149 research outputs found

    Exophiala dermatitidis Revealing Cystic Fibrosis in Adult Patients with Chronic Pulmonary Disease

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    Cystic fibrosis (CF) is a genetic inherited disease due to mutations in the gene cystic fibrosis transmembrane conductance regulator (CFTR). Because of the huge diversity of CFTR mutations, the CF phenotypes are highly heterogeneous, varying from typical to mild form of CF, also called atypical CF. These atypical features are more frequently diagnosed at adolescence or adulthood, and among clinical signs and symptoms leading to suspect a mild form of CF, colonization or infection of the respiratory tract due to well-known CF pathogens should be a warning signal. Exophiala dermatitidis is a melanized dimorphic fungus commonly detected in respiratory specimens from CF patients, but only very rarely from respiratory specimens from non-CF patients. We described here two cases of chronic colonization of the airways by E. dermatitidis, with recurrent pneumonia and hemoptysis in one patient, which led clinicians to diagnose mild forms of CF in these elderly patients who were 68- and 87-year-old. These cases of late CF diagnosis suggest that airway colonization or respiratory infections due to E. dermatitidis in patients with bronchiectasis should led to search for a mild form of CF, regardless of the age and associated symptoms. On a broader level, in patients with chronic respiratory disease and recurrent pulmonary infections, an allergic bronchopulmonary mycosis or an airway colonization by CF-related fungi like E. dermatitidis or some Aspergillus, Scedosporium or Rasamsonia species, should be considered as potential markers of atypical CF and should led clinicians to conduct investigations for CF diagnosis

    200 mm wafer scale III-V/SOI technology for all-optical network-on-chip and signal processing

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    Integrated components, including microdisk lasers, photodetectors, and wavelength selective circuits, for optical network-on-chip and all-optical signal processing are presented using a complementary metal-oxide-semiconductor compatible III-V/silicon-on-insulator integration technology at 200mm wafer scale

    Interplay between charge trapping and polarization switching in BEOL-compatible bilayer Ferroelectric Tunnel Junctions

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    We here report a joint experimental and theoretical analysis of polarization switching in ferroelectric tunnel junctions. Our results show that the injection and trapping of charge into the ferroelectric-dielectric stack has a large influence on the polarization switching. Our results are relevant to the physical understanding and to the design of the devices, and for both memory and memristor applications

    What can be learned from phenotyping and genotyping analyses of Scedosporium prolificans isolates from diverse origins?

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    Introduction: Scedosporium prolificans is a filamentous fungus considered as an emerging opportunistic member of the order Microascaceae. This fungus has a broad clinical spectrum and can cause different types of infections: localized colonization in immunocompetent hosts or disseminated mycosis in immunocompromised patients. Moreover, S. prolificans resistance to most antifungal agents has been reported. Compared to the well characterized Scedosporium / Pseudallescheria complex, little is known about the fundamental aspects of S. prolificans biology, pathogenicity and epidemiology. Aim of the study: Our goal was to characterize a large population of S. prolificans strains, isolated from animals, human, or environment samples in different countries (European, USA and Australia). Results & methods: All strains were prospectively collected, and grown at 30# C on Sabouraud’s agar medium with kanamycin for 1 week. DNA was extracted from subcultures using UltraClean Fecal# DNA kit (MoBio, France). To improve the knowledge of this species at the phylogenetic level, we combined phenotypic criteria such as macroscopic and microscopic morphology features, antifungal susceptibilities based on E-test# method, and genotypic characterization using multi-loci approaches (superoxide dismutase, beta-tubulin and internal transcript spacer genes). Phylogenetic trees were constructed with unambiguously CLUSTALW aligned sequences using the neighbour-joining method with Kimura-2 parameter as substitution model and maximum parsimony analysis, using the BioEdit version 7.0.0 and Phylip version 2.0 softwares. Discussion: Among our collection composed of 59 isolates, we identified three macroscopically different morphotypes of S. prolificans and some genetic polymorphisms (1.8–2.2% difference between the analyzed sequences). These low sequence polymorphisms reflected intra-specific genetic variations. Therefore, we hypothesized that S. prolificans might be stable in space, and apparently insensitive to xenical or environmental factors. No correlation between clinical-biological characteristics and genotypic or phenotypic criteria of S. prolificans strains was found. In conclusion, our results supported the current perception of S. prolificans as a unique species and an emerging opportunistic pathogen

    Analysis of clinical and environmental Candida parapsilosis isolates by microsatellite genotyping – a tool for hospital infections surveillance

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    Candida parapsilosis emerged as an important opportunistic pathogen, causing candidaemia worldwide. Nosocomial outbreaks triggered by this species have been frequently described, particularly in cancer patients. For a better understanding of its epidemiology, several typing methods are used and microsatellite analysis has been reported as highly discriminant. The main objective of this work was to study C. parapsilosis isolates by application of microsatellite genotyping to distinguish epidemiologically related strains, compare clinical and environmental isolates and determine possible routes of dispersion of the isolates in the hospital setting. A total of 129 C. parapsilosis isolates from different origins, including hospital environment and hands of healthcare workers, were genotyped using four microsatellite markers. The isolates were recovered from different health institutions. Analysis of C. parapsilosis isolates from hospital environment showed great genotypic diversity; however, the same or very similar genotypes were also found. The same multilocus genotype was shared by isolates recovered from the hand of a healthcare worker, from the hospital environment and from patients of the same healthcare institution, suggesting that these could be possible routes of transmission and that infections due to C. parapsilosis may be mainly related with exogenous transmission to the patient. Examination of sequential isolates from the same patients showed that colonizing and bloodstream isolates had the same multilocus genotype in the majority of cases. We demonstrate that this typing method is able to distinguish clonal clusters from genetically unrelated genotypes and can be a valuable tool to support epidemiologic investigations in the hospital setting.This research was supported by FCT/MEC, Portugal through Portuguese funds (PIDDAC) - Pest-OE/BIA/UI4050/2014 (CBMA), University of Minho. Raquel Sabino was financially supported by a fellowship from FCT, Portugal (contract BD/22100/2005).info:eu-repo/semantics/publishedVersio

    Random forests to evaluate interspecific interactions in fish distribution models

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    [EN] Previous research indicated that high predictive performance in species distribution modelling can be obtained by combining both biotic and abiotic habitat variables. However, models developed for fish often only address physical habitat characteristics, thus omitting potentially important biotic factors. Therefore, we assessed the impact of biotic variables on fish habitat preferences in four selected stretches of the upper Cabriel River (E Spain). The occurrence of Squalius pyrenaicus and Luciobarbus guiraonis was related to environmental variables describing biotic interactions (inferred by relationships among fish abundances) and channel hydro-morphological characteristics. Random Forests (RF) models were trained and then validated using independent datasets. To build RF models, the conditional variable importance was used together with the model improvement ratio technique. The procedure showed effectiveness in identifying a parsimonious set of not correlated variables, which minimize noise and improve model performance in both training and validation phases. Water depth, channel width, fine substrate and water-surface gradient were selected as most important habitat variables for both fish. Results showed clear habitat overlapping between fish species and suggest that competition is not a strong factor in the study area.This research has been developed in the framework of the HolRiverMed project (FP7-PEOPLE-2010-275577, Marie Curie Actions, Intra-European Fellowships) and the SCARCE project (Assessing and predicting effects on water quantity and quality in Iberian rivers caused by global change, Consolider-Ingenio 2010 CSD2009-00065). Data collection was partially funded by the Spanish Ministry of Environment, Rural and Marine Affairs, the Jucar River Basin District Authority and the Spanish Ministry of Education and Science (POTECOL, CGL2007-66412). We thank Juan Diego Alacaraz-Hernandez, Matias Peredo-Parada and Aina Hernandez-Mascarell for their help with field work and suggestions on data analysis.Vezza, P.; Muñoz Mas, R.; Martinez-Capel, F.; Mouton, A. (2015). Random forests to evaluate interspecific interactions in fish distribution models. Environmental Modelling and Software. 67:173-183. https://doi.org/10.1016/j.envsoft.2015.01.005S1731836
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