24 research outputs found

    The Mobilization of Actinides by Microbial Ligands Taking into Consideration the Final Storage of Nuclear Waste - Interactions of Selected Actinides U(VI), Cm(III), and Np(V) with Pyoverdins Secreted by Pseudomonas fluorescens and Related Model Compounds (Final Report BMBF Project No.: 02E9985)

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    The groundwater bacterium Pseudomonas fluorescens (CCUG 32456) isolated at a depth of 70 m in the Äspö Hard Rock Laboratory secretes a pyoverdin-mixture with four main components (two pyoverdins and two ferribactins). The dominant influence of the pyoverdins of this mixture could be demonstrated by an absorption spectroscopy study. The comparison of the stability constants of U(VI), Cm(III), and Np(V) species with ligands simulating the functional groups of the pyoverdins results in the following order of complex strength: pyoverdins (PYO) > trihydroxamate (DFO) > catecholates (NAP, 6­HQ) > simple hydroxamates (SHA, BHA). The pyoverdin chromophore functionality shows a large affinity to bind actinides. As a result, pyoverdins are also able to complex and to mobilize elements other than Fe(III) at a considerably high efficiency. It is known that EDTA may form the strongest actinide complexes among the various organic components in nuclear wastes. The stability constants of 1:1 species formed between Cm(III) and U(VI) and pyoverdins are by a factor of 1.05 and 1.3, respectively, larger compared to the corresponding EDTA stability constants. The Np(V)-PYO stability constant is even by a factor of 1.83 greater than the EDTA stability constant. The identified Np(V)-PYO species belong to the strongest Np(V) species with organic material reported so far. All identified species influence the actinide speciation within the biologically relevant pH range. The metal binding properties of microbes are mainly determined by functional groups of their cell wall (LPS: Gram-negative bacteria and PG: Gram-positive bacteria). On the basis of the determined stability constants raw estimates are possible, if actinides prefer to interact with the microbial cell wall components or with the secreted pyoverdin bioligands. By taking pH 5 as an example, U(VI)-PYO interactions are slightly stronger than those observed with LPS and PG. For Cm(III) we found a much stronger affinity to aqueous pyoverdin species than to functional groups of the cell wall compartments. A similar behavior was observed for Np(V). This shows the importance of indirect interaction processes between actinides and bioligands secreted by resident microbes

    Clinical efficacy and satisfaction of a digital wheeze detector in a multicentre randomised controlled trial: the WheezeScan study.

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    INTRODUCTION: Wheezing is common in preschool children and its clinical assessment often challenging for caretakers. This study aims to evaluate the impact of a novel digital wheeze detector (WheezeScan™) on disease control in a home care setting. METHODS: A multicentre randomised open-label controlled trial was conducted in Berlin, Istanbul and London. Participants aged 4-84 months with a doctor's diagnosis of recurrent wheezing in the past 12 months were included. While the control group followed usual care, the intervention group received the WheezeScan™ for at-home use for 120 days. Parents completed questionnaires regarding their child's respiratory symptoms, disease-related and parental quality of life, and caretaker self-efficacy at baseline (T0), 90 days (T1) and 4 months (T2). RESULTS: A total of 167 children, with a mean±sd age of 3.2±1.6 years, were enrolled in the study (intervention group n=87; control group n=80). There was no statistically significant difference in wheeze control assessed by TRACK (mean difference 3.8, 95% CI -2.3-9.9; p=0.2) at T1 between treatment groups (primary outcome). Children's and parental quality of life and parental self-efficacy were comparable between both groups at T1. The evaluation of device usability and perception showed that parents found it useful. CONCLUSION: In the current study population, the wheeze detector did not show significant impact on the home management of preschool wheezing. Hence, further research is needed to better understand how the perception and usage behaviour may influence the clinical impact of a digital support

    The Mobilization of Actinides by Microbial Ligands Taking into Consideration the Final Storage of Nuclear Waste - Interactions of Selected Actinides U(VI), Cm(III), and Np(V) with Pyoverdins Secreted by Pseudomonas fluorescens and Related Model Compounds (Final Report BMBF Project No.: 02E9985)

    Get PDF
    The groundwater bacterium Pseudomonas fluorescens (CCUG 32456) isolated at a depth of 70 m in the Äspö Hard Rock Laboratory secretes a pyoverdin-mixture with four main components (two pyoverdins and two ferribactins). The dominant influence of the pyoverdins of this mixture could be demonstrated by an absorption spectroscopy study. The comparison of the stability constants of U(VI), Cm(III), and Np(V) species with ligands simulating the functional groups of the pyoverdins results in the following order of complex strength: pyoverdins (PYO) > trihydroxamate (DFO) > catecholates (NAP, 6­HQ) > simple hydroxamates (SHA, BHA). The pyoverdin chromophore functionality shows a large affinity to bind actinides. As a result, pyoverdins are also able to complex and to mobilize elements other than Fe(III) at a considerably high efficiency. It is known that EDTA may form the strongest actinide complexes among the various organic components in nuclear wastes. The stability constants of 1:1 species formed between Cm(III) and U(VI) and pyoverdins are by a factor of 1.05 and 1.3, respectively, larger compared to the corresponding EDTA stability constants. The Np(V)-PYO stability constant is even by a factor of 1.83 greater than the EDTA stability constant. The identified Np(V)-PYO species belong to the strongest Np(V) species with organic material reported so far. All identified species influence the actinide speciation within the biologically relevant pH range. The metal binding properties of microbes are mainly determined by functional groups of their cell wall (LPS: Gram-negative bacteria and PG: Gram-positive bacteria). On the basis of the determined stability constants raw estimates are possible, if actinides prefer to interact with the microbial cell wall components or with the secreted pyoverdin bioligands. By taking pH 5 as an example, U(VI)-PYO interactions are slightly stronger than those observed with LPS and PG. For Cm(III) we found a much stronger affinity to aqueous pyoverdin species than to functional groups of the cell wall compartments. A similar behavior was observed for Np(V). This shows the importance of indirect interaction processes between actinides and bioligands secreted by resident microbes

    The Mobilization of Actinides by Microbial Ligands Taking into Consideration the Final Storage of Nuclear Waste - Interactions of Selected Actinides U(VI), Cm(III), and Np(V) with Pyoverdins Secreted by Pseudomonas fluorescens and Related Model Compounds (Final Report BMBF Project No.: 02E9985)

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    The groundwater bacterium Pseudomonas fluorescens (CCUG 32456) isolated at a depth of 70 m in the Äspö Hard Rock Laboratory secretes a pyoverdin-mixture with four main components (two pyoverdins and two ferribactins). The dominant influence of the pyoverdins of this mixture could be demonstrated by an absorption spectroscopy study. The comparison of the stability constants of U(VI), Cm(III), and Np(V) species with ligands simulating the functional groups of the pyoverdins results in the following order of complex strength: pyoverdins (PYO) > trihydroxamate (DFO) > catecholates (NAP, 6­HQ) > simple hydroxamates (SHA, BHA). The pyoverdin chromophore functionality shows a large affinity to bind actinides. As a result, pyoverdins are also able to complex and to mobilize elements other than Fe(III) at a considerably high efficiency. It is known that EDTA may form the strongest actinide complexes among the various organic components in nuclear wastes. The stability constants of 1:1 species formed between Cm(III) and U(VI) and pyoverdins are by a factor of 1.05 and 1.3, respectively, larger compared to the corresponding EDTA stability constants. The Np(V)-PYO stability constant is even by a factor of 1.83 greater than the EDTA stability constant. The identified Np(V)-PYO species belong to the strongest Np(V) species with organic material reported so far. All identified species influence the actinide speciation within the biologically relevant pH range. The metal binding properties of microbes are mainly determined by functional groups of their cell wall (LPS: Gram-negative bacteria and PG: Gram-positive bacteria). On the basis of the determined stability constants raw estimates are possible, if actinides prefer to interact with the microbial cell wall components or with the secreted pyoverdin bioligands. By taking pH 5 as an example, U(VI)-PYO interactions are slightly stronger than those observed with LPS and PG. For Cm(III) we found a much stronger affinity to aqueous pyoverdin species than to functional groups of the cell wall compartments. A similar behavior was observed for Np(V). This shows the importance of indirect interaction processes between actinides and bioligands secreted by resident microbes

    Erste Ergebnisse nach Reimplantation bei up-grade des CI Implantates

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    Einleitung: Mittlerweile liegen 30 Jahre Erfahrung in der CI-Versorgung an der MHH vor. Somit taucht die Frage der Reimplantation bei Patienten mit einem technisch "alten", aber intakten Implantat auf. In einer prospektiven Studie werden wir zu den Reimplantationen berichten.Methoden: Die Patientenauswahl orientierte sich am Sprachverstehen unter 30 % Einsilberverstehen (Freiburger Sprachtest) und technischen Unzulänglichkeiten wie einen hohen Energieverbrauch mit häufigem Batteriewechseln. Alle Patienten wurden zur Reimplantation technisch, hno-ärztlich, radiologisch und pädagogisch ausführlich untersucht und beraten. Darauf basierte die abschließende Risikoabwägung. Ergebnis: Bis dato konnten 20 Patienten beraten werden, 3 Patienten reimplantiert werden und weitere 10 Patienten wünschen eine Reimplantation nach Beratung. 2 Patienten wiesen unerwartet in der radiologischen Darstellung den Verdacht auf eine knöchern umbaute Elektrode auf, ohne Hinweise auf eine abgelaufene Infektion. 5 Patienten wiesen eine sehr tief inserierte Elektrode auf. Die Reimplantation der 3 bis dato versorgten Patienten verlief komplikationslos. Erste Ergebnisse im Sprachverstehen zeigen ein gutes Hörvermögen.Schlussfolgerungen: Es besteht die Notwendigkeit auf Patienten zu achten, die aufgrund der bei Ihnen verwendeten Implantate nicht mehr ausreichend versorgt sind. Diese Patienten weisen ein unterdurchschnittliches Sprachverstehen auf und sind in Bezug auf die Energieversorgung und den zur Verfügung stehenden Prozessoren in keinster Weise ausreichend versorgt. Die ersten Ergebnisse dieser Reimplantation zeigen, dass dies weitestgehend komplikationslos mit gutem Erfolg möglich ist. Bis zum Vortragtermin werden weitere Patienten reimplantiert sein und aussagefähige Hörergebnisse vorliegen.Der Erstautor gibt keinen Interessenkonflikt an

    Identification of an AR mutation-negative class of androgen insensitivity by determining endogenous AR activity

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    Context: Only approximately 85%of patients with a clinical diagnosis complete androgen insensitivity syndrome and less than 30%with partial androgen insensitivity syndrome can be explained by inactivating mutations in the androgen receptor (AR) gene. Objective: The objective of the study was to clarify this discrepancy by in vitro determination of AR transcriptional activity in individuals with disorders of sex development (DSD) and male controls. Design: Quantification of DHT-dependent transcriptional induction of the AR target gene apolipoprotein D (APOD) in cultured genital fibroblasts (GFs) (APOD assay) and next-generation sequencing of the complete coding and noncoding AR locus. Setting: The study was conducted at a university hospital endocrine research laboratory. Patients: GFs from 169 individuals were studied encompassing control males (n=68), molecular defined DSD other than androgen insensitivity syndrome (AIS; n = 18), AR mutation-positive AIS (n = 37), and previously undiagnosed DSD including patients with a clinical suspicion of AIS (n=46). Intervention(s): There were no interventions. Main Outcome Measure(s): DHT-dependent APOD expression in cultured GF and AR mutation status in 169 individuals was measured. Results:TheAPODassay clearly separated control individuals (healthy malesandmolecular defined DSD patients other than AIS) from genetically proven AIS (cutoff<2.3-foldAPOD-induction;100%sensitivity, 93.3%specificity, P < .0001). Of 46 DSD individuals with no AR mutation, 17 (37%) fell below the cutoff, indicating disrupted androgen signaling. Conclusions:ARmutation-positive AIS canbereliably identified by theAPODassay. Its combination with next-generation sequencing of the AR locus uncovered an AR mutation-negative, new class of androgen resistance, which we propose to name AIS type II. Our data support the existence of cellular components outside the AR affecting androgen signaling during sexual differentiation with high clinical relevance
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