8 research outputs found

    Dosimetry and calorimetry performance of a scientific CMOS camera for environmental monitoring

    Get PDF
    This paper explores the prospect of CMOS devices to assay lead in drinking water, using calorimetry. Lead occurs together with traces of radioisotopes, e.g.,210 Pb, producing γ-emissions with energies ranging from 10 keV to several 100 keV when they decay; this range is detectable in silicon sensors. In this paper we test a CMOS camera (OXFORD INSTRUMENTS Neo 5.5) for its general performance as a detector of X-rays and low energy γ-rays and assess its sensitivity relative to the World Health Organization upper limit on lead in drinking water. Energies from 6 keV to 60 keV are examined. The CMOS camera has a linear energy response over this range and its energy resolution is for the most part slightly better than 2%. The Neo sCMOS is not sensitive to X-rays with energies below ∼ 10 keV. The smallest detectable rate is 40 ± 3 mHz, corresponding to an incident activity on the chip of 7 ± 4 Bq. The estimation of the incident activity sensitivity from the detected activity relies on geometric acceptance and the measured efficiency vs. energy. We report the efficiency measurement, which is 0.08(2)% (0.0011(2)%) at 26.3 keV (59.5 keV). Taking calorimetric information into account we measure a minimal detectable rate of 4 ± 1 mHz (1.5 ± 0.1 mHz) for 26.3 keV (59.5 keV) γ-rays, which corresponds to an incident activity of 1.0 ± 0.6 Bq (57 ± 33 Bq). Toy Monte Carlo and Geant4 simulations agree with these results. These results show this CMOS sensor is well-suited as a γ-and X-ray detector with sensitivity at the few to 100 ppb level for210 Pb in a sample

    Cardiotrophin-1: A new predictor of atrial fibrillation relapses after successful cardioversion

    No full text
    We aimed to investigate whether or not cardiotrophin-1 (CT-1) can be used as a predictor of sinus rhythm constancy in patients with atrial fibrillation (AF) converted to sinus rhythm. Thirty two patients with AF (48-78 years), without any structural heart disease were enrolled for the study. The control group consisted of 32, age and gender matched healthy persons. Measurements of CT-1 were made after transthoracic and transesophageal echocardiography prior to cardioversion (CV). Relapses of AF were investigated by monthly electrocardiograms (ECGs) and ambulatory ECGs at 1st, 3rd, and 6th month. At the end of 6th month, measurements of CT-1 were repeated. At the beginning patients with AF had increased CT-1 levels when compared to controls (0.94 +/- 0.32 pg/mL vs. 0.30 +/- 0.12 pg/mL, [p < 0.001]). At the end of follow-up of the 32 patients, 17 (53%) had AF relapse. Age, initial duration of AF, left ventricle diameters, ejection fraction, left atrium appendix flow rates were similar among patients with and without AF relapse. However, basal left atrium diameter (4.24 +/- 0.14 cm vs. 4.04 +/- 0.22 cm, p = 0.005), pulmonary artery pressure (32.82 +/- 5 vs. 28.60 +/- 6.23 mmHg, p = 0.004) and CT-1 values (1.08 +/- 0.37 vs. 0.82 +/- 0.16 pg/mL, p = 0.02) were significantly increased in patients with AF relapse. Furthermore, patients with relapsed AF had higher CT-1 levels at 6th month when compared to those in sinus rhythm (1.00 +/- 0.40 vs. 0.71 +/- 0.23 pg/mL). We conclude that post-CV, AF relapses are more frequent among patients with increased baseline CT-1 levels, and CT-1 may be a potential predictor of AF relapse

    Cardiotrophin-1: A new predictor of atrial fibrillation relapses after successful cardioversion

    No full text
    We aimed to investigate whether or not cardiotrophin-1 (CT-1) can be used as a predictor of sinus rhythm constancy in patients with atrial fibrillation (AF) converted to sinus rhythm. Thirty two patients with AF (48-78 years), without any structural heart disease were enrolled for the study. The control group consisted of 32, age and gender matched healthy persons. Measurements of CT-1 were made after transthoracic and transesophageal echocardiography prior to cardioversion (CV). Relapses of AF were investigated by monthly electrocardiograms (ECGs) and ambulatory ECGs at 1st, 3rd, and 6th month. At the end of 6th month, measurements of CT-1 were repeated. At the beginning patients with AF had increased CT-1 levels when compared to controls (0.94 ± 0.32 pg/mL vs. 0.30 ± 0.12 pg/mL, [p < 0.001]). At the end of follow-up of the 32 patients, 17 (53%) had AF relapse. Age, initial duration of AF, left ventricle diameters, ejection fraction, left atrium appendix flow rates were similar among patients with and without AF relapse. However, basal left atrium diameter (4.24 ± 0.14 cm vs. 4.04 ± 0.22 cm, p = 0.005), pulmonary artery pressure (32.82 ± 5 vs. 28.60 ± 6.23 mmHg, p = 0.004) and CT-1 values (1.08 ± 0.37 vs. 0.82 ± 0.16 pg/mL, p = 0.02) were significantly increased in patients with AF relapse. Furthermore, patients with relapsed AF had higher CT-1 levels at 6th month when compared to those in sinus rhythm (1.00 ± 0.40 vs. 0.71 ± 0.23 pg/mL). We conclude that post-CV, AF relapses are more frequent among patients with increased baseline CT-1 levels, and CT-1 may be a potential predictor of AF relapse

    Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

    No full text
    Background: Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation. Methods: WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109. Findings: Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital. Interpretation: In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates. Funding: European Society of Intensive Care Medicine, European Respiratory Society

    Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

    No full text
    Background Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation. Methods WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109. Findings Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0–4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2–6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital. Interpretation In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates
    corecore