68 research outputs found

    Critical evaluation of the FeeNi, FeeTi and FeeNieTi alloy systems

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    The FeeNieTi alloy system has been evaluated, together with FeeNi and FeeTi binary subsystems, to provide reliable information for applications and in view of a thermodynamic modelling of the system. Available literature has been critically evaluated, mainly considering phase constitution and phase equilibria, thermochemical and diffusion data, as well as ab initio atomistic calculations. A discussion of the presently available CALPHAD-type thermodynamic assessments is also presented. Finally, new experimental investigations needed to solve uncertain and contradictory data are suggested

    A European multicentre evaluation of detection and typing methods for human enteroviruses and parechoviruses using RNA transcripts

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    Polymerase chain reaction (PCR) detection has become the gold standard for diagnosis and typing of enterovirus (EV) and human parechovirus (HPeV) infections. Its effectiveness depends critically on using the appropriate sample types and high assay sensitivity as viral loads in cerebrospinal fluid samples from meningitis and sepsis clinical presentation can be extremely low. This study evaluated the sensitivity and specificity of currently used commercial and in-house diagnostic and typing assays. Accurately quantified RNA transcript controls were distributed to 27 diagnostic and 12 reference laboratories in 17 European countries for blinded testing. Transcripts represented the four human EV species (EV-A71, echovirus 30, coxsackie A virus 21, and EV-D68), HPeV3, and specificity controls. Reported results from 48 in-house and 15 commercial assays showed 98% detection frequencies of high copy (1000 RNA copies/5 mu L) transcripts. In-house assays showed significantly greater detection frequencies of the low copy (10 copies/5 mu L) EV and HPeV transcripts (81% and 86%, respectively) compared with commercial assays (56%, 50%; P = 7 x 10(-5)). EV-specific PCRs showed low cross-reactivity with human rhinovirus C (3 of 42 tests) and infrequent positivity in the negative control (2 of 63 tests). Most or all high copy EV and HPeV controls were successfully typed (88%, 100%) by reference laboratories, but showed reduced effectiveness for low copy controls (41%, 67%). Stabilized RNA transcripts provide an effective, logistically simple and inexpensive reagent for evaluation of diagnostic assay performance. The study provides reassurance of the performance of the many in-house assay formats used across Europe. However, it identified often substantially reduced sensitivities of commercial assays often used as point-of-care tests.Peer reviewe

    Molecular Epidemiology and Evolutionary Trajectory of Emerging Echovirus 30, Europe

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    In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >= 2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections.Peer reviewe

    A European multicentre evaluation of detection and typing methods for human enteroviruses and parechoviruses using RNA transcripts

    Get PDF
    Polymerase chain reaction (PCR) detection has become the gold standard for diagnosis and typing of enterovirus (EV) and human parechovirus (HPeV) infections. Its effectiveness depends critically on using the appropriate sample types and high assay sensitivity as viral loads in cerebrospinal fluid samples from meningitis and sepsis clinical presentation can be extremely low. This study evaluated the sensitivity and specificity of currently used commercial and in-house diagnostic and typing assays. Accurately quantified RNA transcript controls were distributed to 27 diagnostic and 12 reference laboratories in 17 European countries for blinded testing. Transcripts represented the four human EV species (EV-A71, echovirus 30, coxsackie A virus 21, and EV-D68), HPeV3, and specificity controls. Reported results from 48 in-house and 15 commercial assays showed 98% detection frequencies of high copy (1000 RNA copies/5 mu L) transcripts. In-house assays showed significantly greater detection frequencies of the low copy (10 copies/5 mu L) EV and HPeV transcripts (81% and 86%, respectively) compared with commercial assays (56%, 50%; P = 7 x 10(-5)). EV-specific PCRs showed low cross-reactivity with human rhinovirus C (3 of 42 tests) and infrequent positivity in the negative control (2 of 63 tests). Most or all high copy EV and HPeV controls were successfully typed (88%, 100%) by reference laboratories, but showed reduced effectiveness for low copy controls (41%, 67%). Stabilized RNA transcripts provide an effective, logistically simple and inexpensive reagent for evaluation of diagnostic assay performance. The study provides reassurance of the performance of the many in-house assay formats used across Europe. However, it identified often substantially reduced sensitivities of commercial assays often used as point-of-care tests

    Molecular epidemiology and evolutionary trajectory of emerging echovirus 30, Europe

    Get PDF
    In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >= 2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections.Molecular basis of virus replication, viral pathogenesis and antiviral strategie

    Freeze-Lining Formation of a Synthetic Lead Slag: Part II. Thermal History

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    Recently, freeze linings have been selected more frequently to protect pyrometallurgical reactor walls, due to a number of advantages over conventional refractory lining such as a self-regenerating capability and the possibility of operating under high-intensity process conditions. A freeze lining is formed on a cooled reactor wall in a time-dependent temperature gradient. To model freeze-lining behavior, input data on several assumptions, such as the phase formation and the temperature at the bath-freeze-lining interface during freeze-lining formation, are needed. In order to provide experimental data, the freeze-lining formation of a synthetic lead slag system (PbO-FeO-Fe2O3-ZnO-CaO-SiO2) is investigated. A lab-scale freeze lining was produced by submerging an air-cooled probe into a liquid slag bath for 120 minutes. The temperature evolution during freeze-lining formation was estimated using the experimentally determined position and composition of the phases, the phase-temperature relations predicted with the thermodynamic computer package FactSage, and the results of reference experiments. For the studied slag system, it is concluded that heat transfer is much faster than mass transfer and crystallization. As a result, the liquid in front of the freeze lining undercools. The degree of undercooling depends on the solidification rate. It is concluded that the temperature at the bath-freeze-lining interface varies between the glass transition and liquidus temperatures of the slag bath during freeze-lining formation

    Epidemiologische surveillance van poliomyelitis. Poliovirus en niet-polio enterovirussen - 2018

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    België&#8239;—&thinsp;Laatste autochtoon geval van poliomyelitis in 1979; laatste geïmporteerd geval in&nbsp;1989. Implicaties voor de Volksgezondheid&#8239;—&thinsp;Het risico op een epidemie in België blijft verwaarloosbaar dankzij een hoge vaccinatiegraad in de 3 gewesten. Maar zolang het virus nog circuleert in de wereld, kan een geval van poliomyelitis worden geïmporteerd in België en kan het virus worden overgedragen op personen die niet of onvolledig gevaccineerd zijn. Het surveillancesysteem moet dus kunnen aantonen dat het poliovirus niet circuleert op het grondgebied en een herintroductie van het virus snel kunnen&nbsp;detecteren.</p

    Modelling of a lead blast furnace

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