Linking Symptom Inventories using Semantic Textual Similarity

An extensive library of symptom inventories has been developed over time to measure clinical symptoms, but this variety has led to several long standing issues. Most notably, results drawn from different settings and studies are not comparable, which limits reproducibility. Here, we present an artificial intelligence (AI) approach using semantic textual similarity (STS) to link symptoms and scores across previously incongruous symptom inventories. We tested the ability of four pre-trained STS models to screen thousands of symptom description pairs for related content - a challenging task typically requiring expert panels. Models were tasked to predict symptom severity across four different inventories for 6,607 participants drawn from 16 international data sources. The STS approach achieved 74.8% accuracy across five tasks, outperforming other models tested. This work suggests that incorporating contextual, semantic information can assist expert decision-making processes, yielding gains for both general and disease-specific clinical assessment

Temporal changes in the epidemiology, management, and outcome from acute respiratory distress syndrome in European intensive care units: a comparison of two large cohorts

Background: Mortality rates for patients with ARDS remain high. We assessed temporal changes in the epidemiology and management of ARDS patients requiring invasive mechanical ventilation in European ICUs. We also investigated the association between ventilatory settings and outcome in these patients. Methods: This was a post hoc analysis of two cohorts of adult ICU patients admitted between May 1–15, 2002 (SOAP study, n = 3147), and May 8–18, 2012 (ICON audit, n = 4601 admitted to ICUs in the same 24 countries as the SOAP study). ARDS was defined retrospectively using the Berlin definitions. Values of tidal volume, PEEP, plateau pressure, and FiO2 corresponding to the most abnormal value of arterial PO2 were recorded prospectively every 24 h. In both studies, patients were followed for outcome until death, hospital discharge or for 60 days. Results: The frequency of ARDS requiring mechanical ventilation during the ICU stay was similar in SOAP and ICON (327[10.4%] vs. 494[10.7%], p = 0.793). The diagnosis of ARDS was established at a median of 3 (IQ: 1–7) days after admission in SOAP and 2 (1–6) days in ICON. Within 24 h of diagnosis, ARDS was mild in 244 (29.7%), moderate in 388 (47.3%), and severe in 189 (23.0%) patients. In patients with ARDS, tidal volumes were lower in the later (ICON) than in the earlier (SOAP) cohort. Plateau and driving pressures were also lower in ICON than in SOAP. ICU (134[41.1%] vs 179[36.9%]) and hospital (151[46.2%] vs 212[44.4%]) mortality rates in patients with ARDS were similar in SOAP and ICON. High plateau pressure (> 29 cmH2O) and driving pressure (> 14 cmH2O) on the first day of mechanical ventilation but not tidal volume (> 8 ml/kg predicted body weight [PBW]) were independently associated with a higher risk of in-hospital death. Conclusion: The frequency of and outcome from ARDS remained relatively stable between 2002 and 2012. Plateau pressure > 29 cmH2O and driving pressure > 14 cmH2O on the first day of mechanical ventilation but not tidal volume > 8 ml/kg PBW were independently associated with a higher risk of death. These data highlight the continued burden of ARDS and provide hypothesis-generating data for the design of future studies

Guided Wave Testing

Guided waves can propagate long distances in thin-walled structures, such as pipelines or plates. This allows for the efficient monitoring and testing of large structures and for the detection of hidden or inaccessible defects. Guided wave propagation is dispersive and multi-modal, requiring a thorough understanding of the wave propagation and scattering phenomena from simulations. Guided wave dispersion diagrams, mode shapes, and typical signals are illustrated for the example of isotropic plates. Both low and high frequency guided waves have been used for the testing of plate structures, with different wave modes and applications including tomography and arrays for the detection and localization of defects. For multilayered and anisotropic structures, guided wave propagation becomes more complex, and often the fundamental guided wave modes are employed for defect detection. For pipelines different commercially available testing systems have been developed and long propagation distances up to 100 m have been achieved. Careful selection of guided wave mode and excitation frequency allows the minimization of attenuation due to viscoelastic coatings and in buried pipelines. Synthetic focusing using non-axisymmetric modes improves defect imaging and localization. Experimental methods differ from standard ultrasonic testing, as good control of the excited guided wave mode shape and signal are required to achieve improved sensitivity for small defects. In addition to contact piezoelectric transducers, electromagnetic and laser techniques allow for noncontact measurements. Finite Element Analysis is one of the numerical simulation techniques used to obtain a better understanding of guided wave testing and to improve defect characterization

Copper uptake and trafficking in the brain

The aim of this chapter is to give a general view on the current status of the scientific basis for the role of copper in human health and disease, outlining the roles of copper in human metabolism and bioenergetics, its coordination chemistry as well as the biological ligands involved in the multiple steps of metal incorporation. In particular, our attention has been focused towards the interaction of copper status and brain function in health and disease, with particular consideration to the role of copper in the pathogenesis of Wilson’s, of Menkes’s, and of human neurodegenerative diseases. Data on interactions between essential trace elements and copper, from the level of absorption in the gut to other systems in the body, are also presented. Particular attention is paid to copper-dependent enzymes in the central nervous system and to copper uptake and trafficking in brain cells

Comparison of European ICU patients in 2012 (ICON) versus 2002 (SOAP)

Purpose: To evaluate differences in the characteristics and outcomes of intensive care unit (ICU) patients over time. Methods: We reviewed all epidemiological data, including comorbidities, types and severity of organ failure, interventions, lengths of stay and outcome, for patients from the Sepsis Occurrence in Acutely ill Patients (SOAP) study, an observational study conducted in European intensive care units in 2002, and the Intensive Care Over Nations (ICON) audit, a survey of intensive care unit patients conducted in 2012. Results: We compared the 3147 patients from the SOAP study with the 4852 patients from the ICON audit admitted to intensive care units in the same countries as those in the SOAP study. The ICON patients were older (62.5 ± 17.0 vs. 60.6 ± 17.4 years) and had higher severity scores than the SOAP patients. The proportion of patients with sepsis at any time during the intensive care unit stay was slightly higher in the ICON study (31.9 vs. 29.6%, p = 0.03). In multilevel analysis, the adjusted odds of ICU mortality were significantly lower for ICON patients than for SOAP patients, particularly in patients with sepsis [OR 0.45 (0.35–0.59), p < 0.001]. Conclusions: Over the 10-year period between 2002 and 2012, the proportion of patients with sepsis admitted to European ICUs remained relatively stable, but the severity of disease increased. In multilevel analysis, the odds of ICU mortality were lower in our 2012 cohort compared to our 2002 cohort, particularly in patients with sepsis. © 2018, The Author(s)