51 research outputs found

    The noise of many needles: Jerky domain wall propagation in PbZrO3 and LaAlO3

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    Measurements of the sample length of PbZrO3 and LaAlO3 under slowly increasing force (3-30 mN/min) yield a superposition of a continuous decrease interrupted by discontinuous drops. This strain intermittency is induced by the jerky movement of ferroelastic domain walls through avalanches near the depinning threshold. At temperatures close to the domain freezing regime, the distributions of the calculated squared drop velocity maxima N(υm2) follow a power law behaviour with exponents Δ=1.6±0.2. This is in good agreement with the energy exponent Δ=1.8±0.2 recently found for the movement of a single needle tip in LaAlO3 [R. J. Harrison and E. K. H. Salje, Appl. Phys. Lett. 97, 021907 (2010)]. With increasing temperature, N(υm2) changes from a power law at low temperatures to an exponential law at elevated temperatures, indicating that thermal fluctuations increasingly enable domain wall segments to unpin even when the driving force is smaller than the corresponding barrier

    Gerschenkron revisited: The new corporate Russia

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    © 2015, Journal of Economic Issues / Association for Evolutionary Economics. Our analysis is based on firm-specific data compiled from the Russian Trading System stock exchange and SKRIN (CKP-H in Russian) database. We seek to identify the factors behind Russias dramatically improved corporate sector performance from the beginning of the 2000s to December 2007. We argue that improved long-term corporate performance was a consequence of several policy initiatives associated with the state-dominated banking sector, which enabled statesubsidized investment funds to be channeled from a structurally reengineered energy sector to targeted investment projects located in other industries. We claim that Russias industrial strategy closely conforms to Alexander Gerschenkrons catch-up theory

    Genomic investigations of unexplained acute hepatitis in children

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    Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

    Update Chronic Viral Hepatitis B and C

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    Der natĂŒrliche Verlauf einer HepatitisB-Virus(HBV)-Infektion ist komplex und wird einerseits durch das Alter zum Zeitpunkt der Infektion, anderseits durch KomorbiditĂ€ten bzw. Koinfektionen und zum Teil noch nicht identifizierte Faktoren bestimmt. Das HBV wird nie komplett eliminiert. Das Erreichen des inaktiven TrĂ€gerstatus ist aber ein realistisches Therapieziel. Zur Therapie stehen Nukleosid/NukleotidAnaloga sowie pegyliertes Interferonalpha zur VerfĂŒgung. Screening von bestimmten Patientengruppen und eine generelle Impfung sind wichtige prophylaktische Massnahmen. Die chronische Hepatitis-C-Virus(HCV) -Infektion fĂŒhrt in circa einem Drittel der FĂ€lle zur Leberzirrhose. Eine Therapie ist generell ab Fibrosestadium Metavir 2 indiziert. Neue DAA (directly acting antivirals) erlauben kurzfristige, hochpotente und nebenwirkungsarme Therapieschemata.Chronic hepatitis B has a complex natural history. The age at infection, comorbidities, coinfections, and other, yet to be identified factors, determine the probability of developing a chronic infection. The HBV virus can never be completely eliminated and remains in the hepatocytes for life. However, to reach an inactive carrier status is a realistic goal of the therapy. For HBV treatment, pegylated interferon and direct antivirals are available. To screen persons at risk and to vaccinate all of the population are important prophylactic measures. Chronic hepatitis C infection leads, in 30% of cases, to liver cirrhosis. Treatment is recommended from fibrosis stage Metavir 2. New DAA allows short treatment, with a high response rate and very few adverse effects.L’histoire naturelle de l’hĂ©patite chronique B est complexe. L’ñge au moment de l’infection, les comorbiditĂ©s, les coinfections et d’autres facteurs pas encore complĂštement identifiĂ©s dĂ©terminent la probabilitĂ© de dĂ©velopper une infection chronique. Le virus HBV ne peut jamais ĂȘtre Ă©liminĂ© complĂštement. Mais il est possible d’atteindre l’état de porteur inactif avec la thĂ©rapie. Le screening des personnes Ă  risque et la vaccination sont essentiels pour la prophylaxie. La thĂ©rapeutique fait appelĂ© Ă  l’interfĂ©ron pegylĂ© ou les antiviraux directs. L’infection HCV peut provoquer une cirrhose et un hĂ©patocarcinome. Le traitement est indiquĂ© en gĂ©nĂ©ral dĂšs le stade F2 de fibrose. Les nouveaux antiviraux directs permettent un traitement court, efficace et avec peu d’effets secondaires
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