12 research outputs found
Effects of thermal shocks on the release of radioisotopes and on molten metal target vessels
The ISOLDE pulsed proton beam peak power amounts to 500 MW during the 2.4 ms proton pulse. The fraction of the proton pulse energy deposited in the target material is at the origin of severe thermal shocks. Quantitative measurement of their effect on the release of radioelements from ISOLDE targets was obtained by comparison of release profiles measured under different proton beam settings. The thermal shock induced in liquids (Pb, Sn, La) lead to mechanical failure of ISOLDE molten metal target vessels. Failure analysis is presented and discussed in the light of the response of mercury samples submitted to the ISOLDE beam and monitored by high-speed optical systems
Reliability Exercise of Ultrasound Salivary Glands in Sjögren's Disease:An International Web Training Initiative
INTRODUCTION: Major salivary gland ultrasonography (SGUS) demonstrated its good metric properties as an outcome measure for diagnosing primary Sjögren's disease (SD). The objective was to assess SGUS reliability among sonographers with different levels of experience, using web training.METHODS: Sonographers from expert centers participated in the reliability exercise. Before exercises, training was done by videoconferencing. Reliability of the two most experienced sonographers (MES) was assessed and then compared to other sonographers. Intra-reader and inter-reader reliability of SGUS items were assessed by computing Cohen's κ coefficients.RESULTS: All sets were read twice by all 14 sonographers within a 4-month interval. Intra-reader reliability of MES was almost perfect for homogeneity, substantial for Outcome Measures in Rheumatology (OMERACT) scoring system (OMERACTss). Among LES (less experienced sonographers), reliability was moderate to almost perfect for homogeneity, fair to moderate for OMERACTss, and fair to almost perfect for binary OMERACTss. Inter-reader reliability between MES was almost perfect for homogeneity, substantial for diagnosis, moderate for OMERACTss, and substantial for binary OMERACTss. Compared to MES, reliabilities of LES were moderate to almost perfect for both homogeneity and diagnosis, only fair to moderate for OMERACTss, but increased in binary OMERACTss.CONCLUSIONS: Videoconferencing training sessions in an international reliability exercise could be an excellent tool to train experienced and less-experienced sonographers. SGUS homogeneity items is useful to distinguish normal from abnormal salivary glands parenchyma independently of diagnosis. Structural damage evaluations by OMERACT scoring system is a new comprehensive score to diagnose patients with SD and could be easily used by sonographers in a binary method.</p
Physical and cognitive impact following SARS-CoV-2 infection in a large population-based case-control study
© 2023. The Author(s).BACKGROUND: Persistent symptoms are common after SARS-CoV-2 infection but correlation with objective measures is unclear. METHODS: We invited all 3098 adults who tested SARS-CoV-2 positive in Iceland before October 2020 to the deCODE Health Study. We compared multiple symptoms and physical measures between 1706 Icelanders with confirmed prior infection (cases) who participated, and 619 contemporary and 13,779 historical controls. Cases participated in the study 5-18 months after infection. RESULTS: Here we report that 41 of 88 symptoms are associated with prior infection, most significantly disturbed smell and taste, memory disturbance, and dyspnea. Measured objectively, cases had poorer smell and taste results, less grip strength, and poorer memory recall. Differences in grip strength and memory recall were small. No other objective measure associated with prior infection including heart rate, blood pressure, postural orthostatic tachycardia, oxygen saturation, exercise tolerance, hearing, and traditional inflammatory, cardiac, liver, and kidney blood biomarkers. There was no evidence of more anxiety or depression among cases. We estimate the prevalence of long Covid to be 7% at a median of 8 months after infection. CONCLUSIONS: We confirm that diverse symptoms are common months after SARS-CoV-2 infection but find few differences between cases and controls in objective parameters measured. These discrepancies between symptoms and physical measures suggest a more complicated contribution to symptoms related to prior infection than is captured with conventional tests. Traditional clinical assessment is not expected to be particularly informative in relating symptoms to a past SARS-CoV-2 infection.Peer reviewe
Automatic fundus image quality assessment on a continuous scale.
To access publisher's full text version of this article click on the hyperlink belowFundus photography is commonly used for screening, diagnosis, and monitoring of various diseases affecting the eye. In addition, it has shown promise in the diagnosis of brain diseases and evaluation of cardiovascular risk factors. Good image quality is important if diagnosis is to be accurate and timely. Here, we propose a method that automatically grades image quality on a continuous scale which is more flexible than binary quality classification. The method utilizes random forest regression models trained on image features discovered automatically by combining basic image filters using simulated annealing as well as features extracted with the discrete Fourier transform. The method was developed and tested on images from two different fundus camera models. The quality of those images was rated on a continuous scale from 0.0 to 1.0 by five experts. In addition, the method was tested on DRIMDB, a publicly available dataset with binary quality ratings. On the DRIMDB dataset the method achieves an accuracy of 0.981, sensitivity of 0.993 and specificity of 0.958 which is consistent with the state of the art. When evaluating image quality on a continuous scale the method outperforms human raters.
Keywords: Fundus image quality assessment; Fundus imaging; Machine learning; Simulated annealing
Predicting the probability of death using proteomics
Publisher Copyright: © 2021, The Author(s).Predicting all-cause mortality risk is challenging and requires extensive medical data. Recently, large-scale proteomics datasets have proven useful for predicting health-related outcomes. Here, we use measurements of levels of 4,684 plasma proteins in 22,913 Icelanders to develop all-cause mortality predictors both for short- and long-term risk. The participants were 18-101 years old with a mean follow up of 13.7 (sd. 4.7) years. During the study period, 7,061 participants died. Our proposed predictor outperformed, in survival prediction, a predictor based on conventional mortality risk factors. We could identify the 5% at highest risk in a group of 60-80 years old, where 88% died within ten years and 5% at the lowest risk where only 1% died. Furthermore, the predicted risk of death correlates with measures of frailty in an independent dataset. Our results show that the plasma proteome can be used to assess general health and estimate the risk of death.Peer reviewe
Reliability Exercise of Ultrasound Salivary Glands in Sjögren’s Disease: An International Web Training Initiative
Abstract Introduction Major salivary gland ultrasonography (SGUS) demonstrated its good metric properties as an outcome measure for diagnosing primary Sjögren’s disease (SD). The objective was to assess SGUS reliability among sonographers with different levels of experience, using web training. Methods Sonographers from expert centers participated in the reliability exercise. Before exercises, training was done by videoconferencing. Reliability of the two most experienced sonographers (MES) was assessed and then compared to other sonographers. Intra-reader and inter-reader reliability of SGUS items were assessed by computing Cohen’s κ coefficients. Results All sets were read twice by all 14 sonographers within a 4-month interval. Intra-reader reliability of MES was almost perfect for homogeneity, substantial for Outcome Measures in Rheumatology (OMERACT) scoring system (OMERACTss). Among LES (less experienced sonographers), reliability was moderate to almost perfect for homogeneity, fair to moderate for OMERACTss, and fair to almost perfect for binary OMERACTss. Inter-reader reliability between MES was almost perfect for homogeneity, substantial for diagnosis, moderate for OMERACTss, and substantial for binary OMERACTss. Compared to MES, reliabilities of LES were moderate to almost perfect for both homogeneity and diagnosis, only fair to moderate for OMERACTss, but increased in binary OMERACTss. Conclusions Videoconferencing training sessions in an international reliability exercise could be an excellent tool to train experienced and less-experienced sonographers. SGUS homogeneity items is useful to distinguish normal from abnormal salivary glands parenchyma independently of diagnosis. Structural damage evaluations by OMERACT scoring system is a new comprehensive score to diagnose patients with SD and could be easily used by sonographers in a binary method
Effects of thermal shocks on the release of radioisotopes and on molten metal target vessels
On the convergence of zero-point vibrational corrections to nuclear shieldings and shielding anisotropies towards the complete basis set limit in water
Post-anaesthesia pulmonary complications after use of muscle relaxants (POPULAR): a multicentre, prospective observational study
Background Results from retrospective studies suggest that use of neuromuscular blocking agents during general
anaesthesia might be linked to postoperative pulmonary complications. We therefore aimed to assess whether the use
of neuromuscular blocking agents is associated with postoperative pulmonary complications.
Methods We did a multicentre, prospective observational cohort study. Patients were recruited from 211 hospitals in
28 European countries. We included patients (aged ≥18 years) who received general anaesthesia for any in-hospital
procedure except cardiac surgery. Patient characteristics, surgical and anaesthetic details, and chart review at discharge
were prospectively collected over 2 weeks. Additionally, each patient underwent postoperative physical examination
within 3 days of surgery to check for adverse pulmonary events. The study outcome was the incidence of postoperative
pulmonary complications from the end of surgery up to postoperative day 28. Logistic regression analyses were
adjusted for surgical factors and patients’ preoperative physical status, providing adjusted odds ratios (ORadj) and
adjusted absolute risk reduction (ARRadj). This study is registered with ClinicalTrials.gov, number NCT01865513.
Findings Between June 16, 2014, and April 29, 2015, data from 22803 patients were collected. The use of neuromuscular
blocking agents was associated with an increased incidence of postoperative pulmonary complications in patients who
had undergone general anaesthesia (1658 [7·6%] of 21694); ORadj 1·86, 95% CI 1·53–2·26; ARRadj –4·4%, 95% CI
–5·5 to –3·2). Only 2·3% of high-risk surgical patients and those with adverse respiratory profiles were anaesthetised
without neuromuscular blocking agents. The use of neuromuscular monitoring (ORadj 1·31, 95% CI 1·15–1·49;
ARRadj –2·6%, 95% CI –3·9 to –1·4) and the administration of reversal agents (1·23, 1·07–1·41; –1·9%, –3·2 to –0·7)
were not associated with a decreased risk of postoperative pulmonary complications. Neither the choice of sugammadex
instead of neostigmine for reversal (ORadj 1·03, 95% CI 0·85–1·25; ARRadj –0·3%, 95% CI –2·4 to 1·5) nor extubation at
a train-of-four ratio of 0·9 or more (1·03, 0·82–1·31; –0·4%, –3·5 to 2·2) was associated with better pulmonary outcomes.
Interpretation We showed that the use of neuromuscular blocking drugs in general anaesthesia is associated with an
increased risk of postoperative pulmonary complications. Anaesthetists must balance the potential benefits of
neuromuscular blockade against the increased risk of postoperative pulmonary complications