183 research outputs found

    Navigating paediatric virology through the COVID‑19 era (Review).

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    The present review article presents the key messages of the 8th Workshop on Paediatric Virology organised virtually by the Institute of Paediatric Virology based on the island of Euboea in Greece. The major topics covered during the workshop were the following: i) New advances in antiviral agents and vaccines against cytomegalovirus; ii) hantavirus nephropathy in children; iii) human rhinovirus infections in children requiring paediatric intensive care; iv) complications and management of human adenovirus infections; v) challenges of post‑coronavirus disease 2019 (COVID‑19) syndrome in children and adolescents; and vi) foetal magnetic resonance imaging in viral infections involving the central nervous system. The COVID‑19 era requires a more intensive, strategic, global scientific effort in the clinic and in the laboratory, focusing on the diagnosis, management and prevention of viral infections in neonates and children

    Measuring sub-mm structural displacements using QDaedalus: a digital clip-on measuring system developed for total stations

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    The monitoring of rigid structures of modal frequencies greater than 5 Hz and sub-mm displacement is mainly based so far on relative quantities from accelerometers, strain gauges etc. Additionally geodetic techniques such as GPS and Robotic Total Stations (RTS) are constrained by their low accuracy (few mm) and their low sampling rates. In this study the application of QDaedalus is presented, which constitutes a measuring system developed at the Geodesy and Geodynamics Lab, ETH Zurich and consists of a small CCD camera and Total Station, for the monitoring of the oscillations of a rigid structure. In collaboration with the Institute of Structural Engineering of ETH Zurich and EMPA, the QDaedalus system was used for monitoring of the sub-mm displacement of a rigid prototype beam and the estimation of its modal frequencies up to 30 Hz. The results of the QDaedalus data analysis were compared to those of accelerometers and proved to hold sufficient accuracy and suitably supplementing the existing monitoring techniques

    Evaluation of natural and tracer fluorescent emission methods for droplet size measurements in a diesel spray

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s12239-012-0070-zSpray sizing that records fluorescent emission and scattered light has been widely applied to spray diagnostics over the last two decades. Different experimental strategies have been developed, but comparing the different solutions offered has remained of interest to experimentalists. In this work, a comparison of two fluorescence strategies for measuring droplet size in the liquid phase of a last-generation DI diesel spray is conducted. The natural fluorescent emission of a commercial diesel fuel and the fluorescence emitted by a tracer (Rhodamine B) are compared using theoretical and experimental approaches. The LIF/Mie ratio commonly called Planar Droplet Sizing (PDS) technique is applied in two different ways to elucidate the possible advantages of using a fluorescent dopant. The sprays were injected under non-evaporative conditions into a constant pressure vessel that simulates densities present at the moment of injection in currently used passenger car diesel engines. Characterization of the signal properties was performed by measuring the absorption coefficient, fluorescence emission spectrum, quantum yield and lifetime of both configurations. The scattered light and fluorescence intensities were calculated to verify the dependencies of the droplet surface and volume. When applying the two techniques to quantify droplet size in dense diesel sprays, the results show that signal weakness and lack of control over the properties of natural fluorescence produce distortion in the shape of the spray and cause measurements to be unreliable. © 2012 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.This research has been funded in the frame of the project PROFUEL reference TRA2011-26293 from Ministerio de Ciencia e Innovacion. The injectors are part of the ECN international project.Pastor Soriano, JV.; Payri, R.; Salavert Fernandez, J.; Manin, J. (2012). Evaluation of natural and tracer fluorescent emission methods for droplet size measurements in a diesel spray. International Journal of Automotive Technology. 13(5):713-724. https://doi.org/10.1007/s12239-012-0070-zS713724135Albrecht, H. E., Damaschke, N., Borys, M. and Tropea, C. (2003). Laser Doppler and Phase Doppler Measurement Techniques. Springer. Berlin.Barnes, M. D., Whitten, W. B. and Ramsey, J. M. (1994). Enhanced fluorescence yields through cavity quantumelectrodynamic effects in microdroplets. J. Optical Society of America B 11,7, 1297–1304.Benajes, J., Molina, S., Novella, R., Amorim, R., Ben Hadj Hamouda, H. and Hardy, J. (2010). Comparison of two injection systems in an HSDI diesel engine using split injection and different injector nozzles. Int. J. Automotive Technology 11,2, 139–146.Charalampous, G. and Hardalupas, Y. (2011). Method to reduce errors of droplet sizing based on the ratio of fluorescent and scattered light intensities (laser-induced fluorescence/Mie technique). Applied Optics, 50, 3622–3637.Chen, G., Mazumder, M., Chang, R. K., Swindal, J. C. and Acker, W. P. (1996). Laser diagnostics for droplet characterization: Application of morphology dependent resonances. Progress in Energy and Combustion Science 22,2, 163–188.Desantes, J. M., Payri, R., Garcia, J. M. and Salvador, F. J. (2007). A contribution to the understanding of isothermal diesel spray dynamics. Fuel 86,7–8, 1093–1101.Domann, R. and Hardalupas, Y. A. (2000). Study of parameters that influence the accuracy of the planar droplet sizing (PDS) technique. Part. Part. Syst. Charact. 3–11.Domann, R. and Hardalupas, Y. A. (2001). Spatial distribution of fluorescence within large doplets and its dependence on dye concentration. Applied Optics 40,21, 3586–3597.Domann, R. and Hardalupas, Y. A. (2002). Quantitative measurement of planar droplet sauter mean diameter in sprays using planar droplet sizing. 11th Int. Symp. Application of Laser Techniques to Fluid Mechanics, Lisbon, Portugal.Eckbreth, A. C. (1988). Laser Diagnostics for Combustion Species and Temperature. Abacus. Cambridge. Mass.Greenhalgh, D. A. (1999). Planar measurements of fuel vapour, liquid fuel, liquid droplet size and soot. Planar Optical Measurement Methods for Gas Turbine Components, 1–7.Im, K., Lin, K., Lai, M. and Chon, M. (2011). Breakup modeling of a liquid jet in cross flow. Int. J. Automotive Technology 12,4, 489–496.Jermy, M. C. and Greenhalgh, D. A. (2000). Planar dropsizing by elastic and fluorescence scattering in sprays too dense for phase doppler measurement. Appl. Phys. B, 71, 703–710.Kim, Y., Kim, K. and Lee, K. (2011). Effect of a 2-stage injection strategy on the combustion and flame characteristics in a PCCI engine. Int. J. Automotive Technology 12,5, 639–644.Ko, F. H., Weng, L. Y., Ko, C. J. and Chu, T. C. (2006). Characterization of imprinting polymeric temperature variation with fluorescent Rhodamine B molecule. Microelectronic Engineering, 83, 864–868.Lakowicz, J. R. (2006). Principles of Fluorescence Spectroscopy. 3rd Edn. Springer.Lee, S. H., Teong, J., Lee, J. T., Ryou, H. S. and Hong, K. (2005). Investigation on spray characteristics under ultrahigh injection pressure conditions. Int. J. Automotive Technology 6,2, 125–131.Lee, B., Song, J., Chang, Y. and Jeon, C. (2010). Effect of the number of fuel injector holes on characteristics of combustion and emissions in a diesel engine. Int. J. Automotive Technology 11,6, 783–791.LeGal, P., Farrugia, N. and Greenhalgh, D. A. (1999). Laser sheet dropsizing of dense sprays. Optics and Laser Techn., 31, 75–83.Lockett, R. D., Richter, J. and Greenhalgh, D. A. (1998). The characterisation of a diesel spray using combined laser induced fluorescence and laser sheet dropsizing. Conf. 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    Metagenomic identification of severe pneumonia pathogens in mechanically-ventilated patients:a feasibility and clinical validity study

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    BACKGROUND: Metagenomic sequencing of respiratory microbial communities for pathogen identification in pneumonia may help overcome the limitations of culture-based methods. We examined the feasibility and clinical validity of rapid-turnaround metagenomics with Nanopore™ sequencing of clinical respiratory specimens. METHODS: We conducted a case-control study of mechanically-ventilated patients with pneumonia (nine culture-positive and five culture-negative) and without pneumonia (eight controls). We collected endotracheal aspirates and applied a microbial DNA enrichment method prior to metagenomic sequencing with the Oxford Nanopore MinION device. For reference, we compared Nanopore results against clinical microbiologic cultures and bacterial 16S rRNA gene sequencing. RESULTS: Human DNA depletion enabled in depth sequencing of microbial communities. In culture-positive cases, Nanopore revealed communities with high abundance of the bacterial or fungal species isolated by cultures. In four cases with resistant clinical isolates, Nanopore detected antibiotic resistance genes corresponding to the phenotypic resistance in antibiograms. In culture-negative pneumonia, Nanopore revealed probable bacterial pathogens in 1/5 cases and Candida colonization in 3/5 cases. In controls, Nanopore showed high abundance of oral bacteria in 5/8 subjects, and identified colonizing respiratory pathogens in other subjects. Nanopore and 16S sequencing showed excellent concordance for the most abundant bacterial taxa. CONCLUSIONS: We demonstrated technical feasibility and proof-of-concept clinical validity of Nanopore metagenomics for severe pneumonia diagnosis, with striking concordance with positive microbiologic cultures, and clinically actionable information obtained from sequencing in culture-negative samples. Prospective studies with real-time metagenomics are warranted to examine the impact on antimicrobial decision-making and clinical outcomes

    Automated office blood pressure measurements in primary care are misleading in more than one third of treated hypertensives: The VALENTINE-Greece Home Blood Pressure Monitoring study

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    Abstract Background This study assessed the diagnostic reliability of automated office blood pressure (OBP) measurements in treated hypertensive patients in primary care by evaluating the prevalence of white coat hypertension (WCH) and masked uncontrolled hypertension (MUCH) phenomena. Methods Primary care physicians, nationwide in Greece, assessed consecutive hypertensive patients on stable treatment using OBP (1 visit, triplicate measurements) and home blood pressure (HBP) measurements (7 days, duplicate morning and evening measurements). All measurements were performed using validated automated devices with bluetooth capacity (Omron M7 Intelli-IT). Uncontrolled OBP was defined as ≥140/90 mmHg, and uncontrolled HBP was defined as ≥135/85 mmHg. Results A total of 790 patients recruited by 135 doctors were analyzed (age: 64.5 ± 14.4 years, diabetics: 21.4%, smokers: 20.6%, and average number of antihypertensive drugs: 1.6 ± 0.8). OBP (137.5 ± 9.4/84.3 ± 7.7 mmHg, systolic/diastolic) was higher than HBP (130.6 ± 11.2/79.9 ± 8 mmHg; difference 6.9 ± 11.6/4.4 ± 7.6 mmHg, p Conclusions In primary care, automated OBP measurements are misleading in approximately 40% of treated hypertensive patients. HBP monitoring is mandatory to avoid overtreatment of subjects with WCH phenomenon and prevent undertreatment and subsequent excess cardiovascular disease in MUCH

    Global, regional, and national burden of low back pain, 1990–2020, its attributable risk factors, and projections to 2050: a systematic analysis of the Global Burden of Disease Study 2021

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    Background: Low back pain is highly prevalent and the main cause of years lived with disability (YLDs). We present the most up-to-date global, regional, and national data on prevalence and YLDs for low back pain from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021. Methods: Population-based studies from 1980 to 2019 identified in a systematic review, international surveys, US medical claims data, and dataset contributions by collaborators were used to estimate the prevalence and YLDs for low back pain from 1990 to 2020, for 204 countries and territories. Low back pain was defined as pain between the 12th ribs and the gluteal folds that lasted a day or more; input data using alternative definitions were adjusted in a network meta-regression analysis. Nested Bayesian meta-regression models were used to estimate prevalence and YLDs by age, sex, year, and location. Prevalence was projected to 2050 by running a regression on prevalence rates using Socio-demographic Index as a predictor, then multiplying them by projected population estimates. Findings: In 2020, low back pain affected 619 million (95% uncertainty interval 554–694) people globally, with a projection of 843 million (759–933) prevalent cases by 2050. In 2020, the global age-standardised rate of YLDs was 832 per 100 000 (578–1070). Between 1990 and 2020, age-standardised rates of prevalence and YLDs decreased by 10·4% (10·9–10·0) and 10·5% (11·1–10·0), respectively. A total of 38·8% (28·7–47·0) of YLDs were attributed to occupational factors, smoking, and high BMI. Interpretation: Low back pain remains the leading cause of YLDs globally, and in 2020, there were more than half a billion prevalent cases of low back pain worldwide. While age-standardised rates have decreased modestly over the past three decades, it is projected that globally in 2050, more than 800 million people will have low back pain. Challenges persist in obtaining primary country-level data on low back pain, and there is an urgent need for more high-quality, primary, country-level data on both prevalence and severity distributions to improve accuracy and monitor change. Funding: Bill and Melinda Gates Foundation

    Learning environment, attitudes and anxiety across the transition from primary to secondary school mathematics

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    Past research has revealed that, relative to primary-school students, high-school students have less-positive attitudes to mathematics and perceive their classroom environments and teacher–student relationships less favourably. This study involved the transition experience of 541 students in 47 classes in 15 primary (year 7) and secondary (year 8) government and Catholic schools in metropolitan and regional South Australia. Scales were adapted from three established instruments, namely, the What Is Happening In this Class?, Test of Mathematics Related Attitudes and Revised Mathematics Anxiety Ratings Scale, to identify changes across the transition from primary to secondary school in terms of the classroom learning environment and students’ attitude/anxiety towards mathematics. Relative to year 7 students, year 8 students reported less Involvement, less positive Attitude to Mathematical Inquiry, less Enjoyment of Mathematics and greater Mathematics Anxiety. Differences between students in Years 7 and 8 were very similar for male and female students, although the magnitude of sex differences in attitudes was slightly different in Years 7 and 8

    Burden of non-communicable diseases among adolescents aged 10–24 years in the EU, 1990–2019: a systematic analysis of the Global Burden of Diseases Study 2019

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    Background: Disability and mortality burden of non-communicable diseases (NCDs) have risen worldwide; however, the NCD burden among adolescents remains poorly described in the EU. Methods: Estimates were retrieved from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Causes of NCDs were analysed at three different levels of the GBD 2019 hierarchy, for which mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) were extracted. Estimates, with the 95% uncertainty intervals (UI), were retrieved for EU Member States from 1990 to 2019, three age subgroups (10–14 years, 15–19 years, and 20–24 years), and by sex. Spearman's correlation was conducted between DALY rates for NCDs and the Socio-demographic Index (SDI) of each EU Member State. Findings: In 2019, NCDs accounted for 86·4% (95% uncertainty interval 83·5–88·8) of all YLDs and 38·8% (37·4–39·8) of total deaths in adolescents aged 10–24 years. For NCDs in this age group, neoplasms were the leading causes of both mortality (4·01 [95% uncertainty interval 3·62–4·25] per 100 000 population) and YLLs (281·78 [254·25–298·92] per 100 000 population), whereas mental disorders were the leading cause for YLDs (2039·36 [1432·56–2773·47] per 100 000 population) and DALYs (2040·59 [1433·96–2774·62] per 100 000 population) in all EU Member States, and in all studied age groups. In 2019, among adolescents aged 10–24 years, males had a higher mortality rate per 100 000 population due to NCDs than females (11·66 [11·04–12·28] vs 7·89 [7·53–8·23]), whereas females presented a higher DALY rate per 100 000 population due to NCDs (8003·25 [5812·78–10 701·59] vs 6083·91 [4576·63–7857·92]). From 1990 to 2019, mortality rate due to NCDs in adolescents aged 10–24 years substantially decreased (–40·41% [–43·00 to –37·61), and also the YLL rate considerably decreased (–40·56% [–43·16 to –37·74]), except for mental disorders (which increased by 32·18% [1·67 to 66·49]), whereas the YLD rate increased slightly (1·44% [0·09 to 2·79]). Positive correlations were observed between DALY rates and SDIs for substance use disorders (rs=0·58, p=0·0012) and skin and subcutaneous diseases (rs=0·45, p=0·017), whereas negative correlations were found between DALY rates and SDIs for cardiovascular diseases (rs=–0·46, p=0·015), neoplasms (rs=–0·57, p=0·0015), and sense organ diseases (rs=–0·61, p=0·0005). Interpretation: NCD-related mortality has substantially declined among adolescents in the EU between 1990 and 2019, but the rising trend of YLL attributed to mental disorders and their YLD burden are concerning. Differences by sex, age group, and across EU Member States highlight the importance of preventive interventions and scaling up adolescent-responsive health-care systems, which should prioritise specific needs by sex, age, and location. Funding: Bill & Melinda Gates Foundation
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