702 research outputs found

    Untersuchung einer neuen Herzklappe für Herzunterstützungssysteme

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Ein bewährtes Verfahren zur Behandlung erkrankter natürlicher Heizklappen ist die Implantation von Heizklappenprothesen. Neben diesem Einsatz entwickelt sich zur Zeit ein weiteres Anwendungsgebiet; der Einsatz von Herzklappenprothesen in Herzunterstützungssystemen. Eine häufig dabei auftretende Komplikation stellt die Thrombenbildung dar. Diese tritt insbesondere im Bereich der verwendeten Herzklappenprothesen auf. Bei einer Implantation einer Heizklappenprothese ist ihre unmittelbare Umgebung durch die Anatomie vorgegeben. Bei einem Einsatz in einem Herzunterstützungssystem dagegen kann diese Umgebung frei gestaltet werden. Mit diesem Ansatz ergeben sich für die strömungstechnische Gestaltung der Herzklappen für Blutpumpen ganz neue Möglichkeiten. Die unmittelbare Umgebung der Klappe ist der Strömungskanal. Mit dem neuen, hier vorgestellten S-förmigen Strömungskanal der Klappe scheint es möglich zu sein, die Gefahr der Thrombenbildung zu reduzieren. Insbesondere die Vermeidung von Ablösungen führt zu einer Verringerung des Risikos der Thrombenbildung und ermöglicht damit eine verminderte Dosierung von Antikoagulantien

    Adverse Selection and Moral Hazard in Anonymous Markets

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    Endoparasitic infections and prevention measures in sheep and goats under mountain farming conditions in Northern Italy

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    Abstract In mountainous areas, where small ruminants form an integral part of livestock farming, an effective control of parasites is of high importance, because the animals are grazing on communal pasture land during the summer months. But knowledge on the infection status of the animals, which is needed for an effective control, is very limited in these areas. Therefore, this study aimed to assess the prevalence of endoparasitic infections and the use of preventive measures in sheep and goat farms in South Tyrol, a mountainous region of Northern Italy. A questionnaire was used to collect information on farm structure and management as well as routine parasite control measures. Following the survey, a total of 3536 individual fecal samples from 123 sheep and goat flocks were analysed over three periods in autumn 2015, spring and autumn 2016 with routine methods including fecal egg counts (FEC) and oocysts counts (FOC). Animals were classified into 12 months of age. Goat flocks had an average herd size of 31 (range 5–125) and sheep flocks of 28 animals (range 2–100). Mountain sheep and goat breeds were dominant. More than 60% of the sheep and 40% the goat flocks were grazed on communal summer pastures at altitudes >1500 m a.s.l. Both sheep and goat farmers perceived gastrointestinal strongylid nematodes (GIN) as the most frequent parasites. Only 16% of the sheep and 30% of the goat farmers ever before this study did coprological examinations. More than 90% of the farms applied anthelmintic treatments; usually once (sheep: 32%, goats: 53%) or twice (sheep: 68%, goats: 42%) per year. Independent of the season, macrocyclic lactones were the most commonly used anthelmintics. More than 30% of the sheep-12 months and 16% >12 months were GIN-negative. Sheep  0.05). Third-stage larvae identified in coprocultures were dominated by Teladorsagia/Trichostrongylus in both sheep (56.5 ± 24.5%) and goats (60.5 ± 25.8%). While in sheep lambs had a higher FOC than both other age classes, kids did not differ from goats at an age of 7–12 months but only from those >12 months (P  12 months, while these parasites were identified in 18.5, 7.3 and 5.7% in goats 12 months, respectively. The prevalence of lungworms at flock level varied between seasons from 18 to 50% in sheep and 44–78% in goats. This first report on endoparasitic infections of sheep and goats in the mountainous region of South Tyrol reveals a high prevalence of endoparasites, especially GIN at a medium infection level, tapeworms and lungworms. Anthelmintics are regularly used, while fecal sampling for selective treatment only exceptionally. Therefore, parasite control measures should be optimized to reduce the risk for the development of anthelmintic resistance, which was already reported from neighboring regions

    Laminated Monolithic Perovskite/Silicon Tandem Photovoltaics

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    Perovskite/silicon tandem photovoltaics have attracted enormous attention in science and technology over recent years. In order to improve the performance and stability of the technology, new materials and processes need to be investigated. However, the established sequential layer deposition methods severely limit the choice of materials and accessible device architectures. In response, a novel lamination process that increases the degree of freedom in processing the top perovskite solar cell (PSC) is proposed. The very first prototypes of laminated monolithic perovskite/silicon tandem solar cells with stable power output efficiencies of up to 20.0% are presented. Moreover, laminated single-junction PSCs are on par with standard sequential layer deposition processed devices in the same architecture. The numerous advantages of the lamination process are highlighted, in particular the opportunities to engineer the perovskite morphology, which leads to a reduction of non-radiative recombination losses and and an enhancement in open-circuit voltage (Voc). Laminated PSCs exhibit improved stability by retaining their initial efficiency after 1-year aging and show good thermal stability under prolonged illumination at 80 °C. This lamination approach enables the research of new architectures for perovskite-based photovoltaics and paves a new route for processing monolithic tandem solar cells even with a scalable lamination process

    The proteolytic activation of (H3N2) influenza A virus hemagglutinin is facilitated by different type II transmembrane serine proteases

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    Cleavage of influenza virus hemagglutinin (HA) by host cell proteases is necessary for viral activation and infectivity. In humans and mice, members of the type II transmembrane protease family (TTSP), e.g., TMPRSS2, TMPRSS4, and TMPRSS11d (HAT), have been shown to cleave influenza virus HA for viral activation and infectivity in vitro. Recently, we reported that inactivation of a single HA-activating protease gene, Tmprss2, in knockout mice inhibits the spread of H1N1 influenza viruses. However, after infection of Tmprss2 knockout mice with an H3N2 influenza virus, only a slight increase in survival was observed, and mice still lost body weight. In this study, we investigated an additional trypsin-like protease, TMPRSS4. Both TMPRSS2 and TMPRSS4 are expressed in the same cell types of the mouse lung. Deletion of Tmprss4 alone in knockout mice does not protect them from body weight loss and death upon infection with H3N2 influenza virus. In contrast, Tmprss2-/- Tmprss4-/- double-knockout mice showed a remarkably reduced virus spread and lung pathology, in addition to reduced body weight loss and mortality. Thus, our results identified TMPRSS4 as a second host cell protease that, in addition to TMPRSS2, is able to activate the HA of H3N2 influenza virus in vivo

    Multi-level evidence of an allelic hierarchy of USH2A variants in hearing, auditory processing and speech/language outcomes.

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    Language development builds upon a complex network of interacting subservient systems. It therefore follows that variations in, and subclinical disruptions of, these systems may have secondary effects on emergent language. In this paper, we consider the relationship between genetic variants, hearing, auditory processing and language development. We employ whole genome sequencing in a discovery family to target association and gene x environment interaction analyses in two large population cohorts; the Avon Longitudinal Study of Parents and Children (ALSPAC) and UK10K. These investigations indicate that USH2A variants are associated with altered low-frequency sound perception which, in turn, increases the risk of developmental language disorder. We further show that Ush2a heterozygote mice have low-level hearing impairments, persistent higher-order acoustic processing deficits and altered vocalizations. These findings provide new insights into the complexity of genetic mechanisms serving language development and disorders and the relationships between developmental auditory and neural systems

    Interoperable atlases of the human brain

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    International audienceThe last two decades have seen an unprecedented development of human brain mapping approaches at various spatial and temporal scales. Together, these have provided a large fundus of information on many different as-pects of the human brain including micro-and macrostructural segregation, regional specialization of function, connectivity, and temporal dynamics. Atlases are central in order to integrate such diverse information in a topo-graphically meaningful way. It is noteworthy, that the brain mapping field has been developed along several major lines such as structure vs. function, postmortem vs. in vivo, individual features of the brain vs. population-based aspects, or slow vs. fast dynamics. In order to understand human brain organization, however, it seems inevitable that these different lines are integrated and combined into a multimodal human brain model. To this aim, we held a workshop to determine the constraints of a multi-modal human brain model that are needed to enable (i) an integration of different spatial and temporal scales and data modalities into a common reference system, and (ii) efficient data exchange and analysis. As detailed in this report, to arrive at fully interoperable atlases of the human brain will still require much work at the frontiers of data acquisition, analysis, and represen-tation. Among them, the latter may provide the most challenging task, in particular when it comes to representing features of vastly different scales of space, time and abstraction. The potential benefits of such endeavor, however, clearly outweigh the problems, as only such kind of multi-modal human brain atlas may provide a starting point from which the complex relationships between structure, function, and connectivity may be explored

    Large-scale associations between the leukocyte transcriptome and BOLD responses to speech differ in autism early language outcome subtypes.

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    Heterogeneity in early language development in autism spectrum disorder (ASD) is clinically important and may reflect neurobiologically distinct subtypes. Here, we identified a large-scale association between multiple coordinated blood leukocyte gene coexpression modules and the multivariate functional neuroimaging (fMRI) response to speech. Gene coexpression modules associated with the multivariate fMRI response to speech were different for all pairwise comparisons between typically developing toddlers and toddlers with ASD and poor versus good early language outcome. Associated coexpression modules were enriched in genes that are broadly expressed in the brain and many other tissues. These coexpression modules were also enriched in ASD-associated, prenatal, human-specific, and language-relevant genes. This work highlights distinctive neurobiology in ASD subtypes with different early language outcomes that is present well before such outcomes are known. Associations between neuroimaging measures and gene expression levels in blood leukocytes may offer a unique in vivo window into identifying brain-relevant molecular mechanisms in ASD

    Functional near infrared spectroscopy (fNIRS) to assess cognitive function in infants in rural Africa

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    Cortical mapping of cognitive function during infancy is poorly understood in low-income countries due to the lack of transportable neuroimaging methods. We have successfully piloted functional near infrared spectroscopy (fNIRS) as a neuroimaging tool in rural Gambia. Four-to-eight month old infants watched videos of Gambian adults perform social movements, while haemodynamic responses were recorded using fNIRS. We found distinct regions of the posterior superior temporal and inferior frontal cortex that evidenced either visual-social activation or vocally selective activation (vocal > non-vocal). The patterns of selective cortical activation in Gambian infants replicated those observed within similar aged infants in the UK. These are the first reported data on the measurement of localized functional brain activity in young infants in Africa and demonstrate the potential that fNIRS offers for field-based neuroimaging research of cognitive function in resource-poor rural communities
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