155 research outputs found

    Diagnostic imaging in adult non-cystic fibrosis bronchiectasis.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadRadiology plays a key role in the diagnosis of bronchiectasis, defined as permanent dilatation of the bronchial lumen. Volumetric thin-section multidetector computed tomography is an excellent noninvasive modality to evaluate bronchiectasis. Bronchiectasis is categorised by morphological appearance. Cylindrical bronchiectasis has a smooth tubular configuration and is the most common form. Varicose bronchiectasis has irregular contours with alternating dilating and contracting lumen. Cystic bronchiectasis is the most severe form and exhibits saccular dilatation of bronchi. Bronchial dilatation is the hallmark of bronchiectasis and is evaluated in relation to the accompanying pulmonary artery. A broncho-arterial ratio exceeding 1:1 should be considered abnormal. Normal bronchi are narrower in diameter the further they are from the lung hila. Lack of normal bronchial tapering over 2 cm in length, distal from an airway bifurcation, is the most sensitive sign of bronchiectasis. Findings commonly associated with bronchiectasis include bronchial wall thickening, mucus plugging and tree-in-bud opacities. Bronchiectasis results from a myriad of conditions, with post-infectious bronchiectasis being the most common. Imaging can sometimes discern the cause of bronchiectasis. However, in most cases it is nonspecific or only suggestive of aetiology. While morphological types are nonspecific, the distribution of abnormality offers clues to aetiology. KEY POINTS: Bronchiectasis is a chronic progressive condition with significant disease burden and frequent exacerbations, for which the diagnosis relies on cross-sectional imaging.The major imaging findings include bronchial dilatation, bronchial contour abnormalities and visualisation of the normally invisible peripheral airways.Bronchiectasis is the end result of various conditions, including immunodeficiencies, mucociliary disorders and infections. Imaging is often nonspecific with regard to aetiology but can be suggestive.Distribution of abnormality in the lung offers helpful clues for establishing aetiology. EDUCATIONAL AIMS: To review the cross-sectional imaging appearance of bronchiectasis and the common associated findings.To get a sense of how radiology can aid in establishing the aetiology of bronchiectasis

    Transient magnetotransport through a quantum wire

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    We consider an ideal parabolic quantum wire in a perpendicular magnetic field. A simple Gaussian shaped scattering potential well or hill is flashed softly on and off with its maximum at t=0t=0, mimicking a temporary broadening or narrowing of the wire. By an extension of the Lippmann-Schwinger formalism to time-dependent scattering potentials we investigate the effects on the continuous current that is driven through the quantum wire with a vanishingly small forward bias. The Lippmann-Schwinger approach to the scattering process enables us to investigate the interplay between geometrical effects and effects caused by the magnetic field.Comment: RevTeX (pdf-LaTeX), 11 pages with 15 included jpg figure

    Volcanic eruptions and toxic gases

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    Pulmonary embolism: victories and future hopes.

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    Time-dependent magnetotransport of a wave packet in a quantum wire with embedded quantum dots

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    We consider wave packet propagation in a quantum wire with either an embedded antidot or an embedded parallel double open quantum dot under the influence of a uniform magnetic field. The magnetoconductance and the time evolution of an electron wave packet are calculated based on the Lippmann-Schwinger formalism. This approach allows us to look at arbitrary embedded potential profiles and illustrate the results by performing computational simulations for the conductance and the time evolution of the electron wave packet through the quantum wire. In the double-dot system we observe a long-lived resonance state that enhances the spatial spreading of the wave packet, and quantum skipping-like trajectories are induced when the envelop function of the wave packet covers several subbands in appropriate magnetic fields.Comment: RevTeX, 9 pages with 8 included postscript figure

    Long-term survival in patients hospitalized for chronic obstructive pulmonary disease: a prospective observational study in the Nordic countries.

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.Mortality rate is high in patients with chronic obstructive pulmonary disease (COPD). Our aim was to investigate long-term mortality and associated risk factors in COPD patients previously hospitalized for a COPD exacerbation. A total of 256 patients from the Nordic countries were followed for 8.7 ± 0.4 years after the index hospitalization in 2000-2001. Prior to discharge, the St George's Respiratory Questionnaire was administered and data on therapy and comorbidities were obtained. Information on long-term mortality was obtained from national registries in each of the Nordic countries. In total, 202 patients (79%) died during the follow up period, whereas 54 (21%) were still alive. Primary cause of death was respiratory (n = 116), cardiovascular (n = 43), malignancy (n = 28), other (n = 10), or unknown (n = 5). Mortality was related to older age, with a hazard risk ratio (HRR) of 1.75 per 10 years, lower forced expiratory volume in 1 second (FEV(1)) (HRR 0.80), body mass index (BMI) <20 kg/m(2) (HRR 3.21), and diabetes (HRR 3.02). Older age, lower BMI, and diabetes were related to both respiratory and cardiovascular mortality. An association was also found between lower FEV(1) and respiratory mortality, whereas mortality was not significantly associated with therapy, anxiety, or depression. Almost four out of five patients died within 9 years following an admission for COPD exacerbation. Increased mortality was associated with older age, lower lung function, low BMI, and diabetes, and these factors should be taken into account when making clinical decisions about patients who have been admitted to hospital for a COPD exacerbation.Boehringer Ingelheim Swedish Heart and Lung Association Swedish Heart Lung Foundatio

    Ambient nitrogen dioxide is associated with emergency hospital visits for atrial fibrillation: a population-based case-crossover study in Reykjavik, Iceland.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: In Iceland air quality is generally good; however, previous studies indicate that there is an association between air pollution in Reykjavik and adverse health effects as measured by dispensing of medications, mortality, and increase in health care utilisation. The aim was to study the association between traffic-related ambient air pollution in the Reykjavik capital area and emergency hospital visits for heart diseases and particularly atrial fibrillation and flutter (AF). Methods: A multivariate time-stratified case-crossover design was used to study the association. Cases were those patients aged 18 years or older living in the Reykjavik capital area during the study period, 2006-2017, who made emergency visits to Landspitali University Hospital for heart diseases. In this population-based study, the primary discharge diagnoses were registered according to International Classification of Diseases, 10th edition (ICD-10). The pollutants studied were NO2, PM10, PM2.5, and SO2, with adjustment for H2S, temperature, and relative humidity. The 24-h mean of pollutants was used with lag 0 to lag 4. Results: During the study period 9536 cases of AF were identified. The 24-h mean NO2 was 20.7 ÎĽg/m3. Each 10 ÎĽg/m3 increase in NO2 was associated with increased risk of heart diseases (ICD-10: I20-I25, I44-I50), odds ratio (OR) 1.023 (95% CI 1.012-1.034) at lag 0. Each 10 ÎĽg/m3 increase in NO2 was associated with an increased risk of AF (ICD-10: I48) on the same day, OR 1.030 (95% CI: 1.011-1.049). Females were at higher risk for AF, OR 1.051 (95% CI 1.019-1.083) at lag 0, and OR 1.050 (95% CI 1.019-1.083) at lag 1. Females aged younger than 71 years had even higher risk for AF, OR 1.077 (95% CI: 1.025-1.131) at lag 0. Significant associations were found for other pollutants and emergency hospital visits, but they were weaker and did not show a discernable pattern. Conclusions: Short-term increase in NO2 concentrations was associated with heart diseases, more precisely with AF. The associations were stronger among females, and among females at younger age. This is the first study in Iceland that finds an association between air pollution and cardiac arrhythmias, so the results should be interpreted with caution. Keywords: Atrial fibrillation; Cardiac arrhythmia; Case-crossover; Hospital registry; Ischemic heart diseases; Nitrogen dioxide; Population-based

    Ambient air pollution and emergency department visits and hospitalisation for cardiac arrest : a population-based case-crossover study in Reykjavik, Iceland

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    Publisher Copyright: © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. Publisher Copyright: © 2023 Authors. All rights reserved.OBJECTIVES: To assess the association between traffic-related ambient air pollution and emergency hospital visits for cardiac arrest. DESIGN: Case-crossover design was used with a lag time to 4 days. SETTING: The Reykjavik capital area and the study population was the inhabitants 18 years and older identified by encrypted personal identification numbers and zip codes. PARTICIPANTS AND EXPOSURE: Cases were those with emergency visits to Landspitali University Hospital during the period 2006-2017 and who were given the primary discharge diagnosis of cardiac arrest according to the International Classification of Diseases 10th edition (ICD-10) code I46. The pollutants were nitrogen dioxide (NO2), particulate matter with aerodynamic diameter less than 10 µm (PM10), particulate matter with aerodynamic diameter less than 2.5 µm (PM2.5) and sulfur dioxide (SO2) with adjustment for hydrogen sulfide (H2S), temperature and relative humidity. MAIN OUTCOME MEASURE: OR and 95% CIs per 10 µg/m3 increase in concentration of pollutants. RESULTS: The 24-hour mean NO2 was 20.7 µg/m3, mean PM10 was 20.5 µg/m3, mean PM2.5 was 12.5 µg/m3 and mean SO2 was 2.5 µg/m3. PM10 level was positively associated with the number of emergency hospital visits (n=453) for cardiac arrest. Each 10 µg/m3 increase in PM10 was associated with increased risk of cardiac arrest (ICD-10: I46), OR 1.096 (95% CI 1.033 to 1.162) on lag 2, OR 1.118 (95% CI 1.031 to 1.212) on lag 0-2, OR 1.150 (95% CI 1.050 to 1.261) on lag 0-3 and OR 1.168 (95% CI 1.054 to 1.295) on lag 0-4. Significant associations were shown between exposure to PM10 on lag 2 and lag 0-2 and increased risk of cardiac arrest in the age, gender and season strata. CONCLUSIONS: A new endpoint was used for the first time in this study: cardiac arrest (ICD-10 code: I46) according to hospital discharge registry. Short-term increase in PM10 concentrations was associated with cardiac arrest. Future ecological studies of this type and their related discussions should perhaps concentrate more on precisely defined endpoints.Peer reviewe

    Effects of Eyjafjallajökull volcanic ash on innate immune system responses and bacterial growth in vitro.

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    To access publisher's full text version of this article click on the hyperlink at the bottom of the pageOn 20 March 2010, the Icelandic volcano Eyjafjallajökull erupted for the first time in 190 years. Despite many epidemiological reports showing effects of volcanic ash on the respiratory system, there are limited data evaluating cellular mechanisms involved in the response to ash. Epidemiological studies have observed an increase in respiratory infections in subjects and populations exposed to volcanic eruptions.We physicochemically characterized volcanic ash, finding various sizes of particles, as well as the presence of several transition metals, including iron. We examined the effect of Eyjafjallajökull ash on primary rat alveolar epithelial cells and human airway epithelial cells (20-100 µg/cm(2)), primary rat and human alveolar macrophages (5-20 µg/cm(2)), and Pseudomonas aeruginosa (PAO1) growth (3 µg/104 bacteria).Volcanic ash had minimal effect on alveolar and airway epithelial cell integrity. In alveolar macrophages, volcanic ash disrupted pathogen-killing and inflammatory responses. In in vitro bacterial growth models, volcanic ash increased bacterial replication and decreased bacterial killing by antimicrobial peptides.These results provide potential biological plausibility for epidemiological data that show an association between air pollution exposure and the development of respiratory infections. These data suggest that volcanic ash exposure, while not seriously compromising lung cell function, may be able to impair innate immunity responses in exposed individuals.National Institutes of Health (NIH) R01 HL079901 NIH RO1 HL096625 R21HL109589 National Science Foundation NSF-EAR0821615 National Institute of Environmental Health Sciences (NIEHS) through the University of Iowa Environmental Health Sciences Research Center NIEHS/NIH P30 ES005605 National Center for Research Resources, NI
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