754 research outputs found
Intravascular Large B-Cell Lymphoma Presenting as Dementia and Hemolytic Anemia
Background: Intravascular lymphoma (IVL) is an uncommon disease characterized by atypical lymphoid cells growing inside the lumina of small vessels. The diversity of clinical presentation due to possible involvement of multiple organs often complicates its diagnosis. Case Report: Here, we report on a case of IVL with rapidly progressive dementia and Coombs-negative hemolytic anemia. Interestingly, the erythrocytes exhibited a decreased osmotic resistance. Bone marrow histopathology revealed increased erythropoiesis and, finally, a small monoclonal B lymphocyte population. Cerebral magnetic resonance imaging (MRI) demonstrated few micro-bleedings. Computed tomography (CT) showed bilateral ground-glass opacity of the lungs. Within a few days, the patient developed respiratory failure and died. On post-mortem examination, intravascular large B-cell lymphoma with almost complete infiltration of the brain and lungs was diagnosed. Conclusion: IVL should be considered early in situations of unexplained neuropsychiatric disease along with markedly elevated levels of lactic dehydrogenase, anemia, and hemolysis
Synthese, Untersuchung und Anwendung neuartiger Fluorophore fĂĽr organische Leuchtdioden und Sensorik
Die vorliegende Arbeit beschäftigt sich im ersten Teil mit der Synthese, Charakterisierung
und Anwendung neuartiger TADF-Emittermaterialien zur Optimierung der Quantenausbeute
und der Effizienz des Triplett-Singulett-Ăśbergangs. Auf Grundlage von Diphenylsulfonen
wurden zunächst durch zeiteffiziente Synthesen zahlreiche Akzeptorstrukturen mit
systematischen Variationen hergestellt und mit Carbazol als Donor in Lösung spektroskopisch
untersucht. Im zweiten Schritt wurden die Donoren durch bekannte und neu entwickelte
ausgetauscht, um die Quantenausbeuten zu erhöhen und die Lebenszeiten
angeregter Zustände zu senken sowie eine Prozessierung aus Lösung zu ermöglichen. Dies
gelang durch sterische Verdrehung der aromatischen Ringe der Diphenyleinheit. Die hier
gezeigten Moleküle wurden in Lösung und im Film detailliert spektroskopisch und
energetisch untersucht und in ausreichender Menge hergestellt, sodass sie durch
Kooperationspartner als Emitter in OLEDs verwendet wurden.
Mit Quantenausbeuten von ungefähr 80 % sowohl in Lösung als auch im Film lagen die entwickelten
Materialien unter den besten bekannten blauen TADF-Emittern.
Im Rahmen des zweiten Teils der Arbeit wurden Distyrylbenzole entwickelt, die intramolekulare
Wechselwirkungen zwischen einer (Diethylamino)methylen-Seitenkette sowie
einer Carbonylgruppe aufweisen.
Zahlreiche Derivate mit diesem Substitutionsmuster konnten synthetisiert und die Veränderung
der Fluoreszenz bei Aufhebung der beschriebenen Wechselwirkung durch Säure
gezeigt werden, was eine Verwendung als Sensoren ermöglicht. Mit Nitril- und Sulfonresten
konnte das Konzept auf weitere Substituenten mit polarisierten Mehrfachbindungen, jedoch
ohne Carbonylgruppen, ausgeweitet werden
Origin of high Zn contents in Jurassic limestone of the Jura mountain range and the Burgundy: evidence from Zn speciation and distribution
In order to better understand the origin and enrichment mechanisms leading to elevated Zn concentrations in Jurassic limestone of the Jura mountain range (JMR) and the Burgundy (B), we investigated four locations of Bajocian age (JMR: Lausen-Schleifenberg, Gurnigel; B: Vergisson-Davayé, Lucy-le-Bois) and two locations of Oxfordian age (JMR: Dornach, Pichoux) for their Zn distribution and speciation. Measurements of the acid-extractable and bulk Zn contents showed that Zn is stratigraphically and spatially heterogeneously distributed, in association with permeable carbonate levels. Up to 3,580 and 207mg/kg Zn was detected in Bajocian and Oxfordian limestone, respectively, with numerous limestone samples having Zn contents above 50mg/kg. Using X-ray absorption near edge structure spectroscopy and micro-X-ray fluorescence spectrometry, the speciation and micro-scale distribution of Zn was investigated for selected limestone samples. In Bajocian limestone sphalerite and/or Zn-substituted goethite and a minor fraction of Zn-bearing carbonates were identified. In contrast, Zn-bearing carbonates (Zn-substituted calcite and hydrozincite) were accounting for most of the total Zn in Oxfordian limestone. The micro-scale distribution of Zn for Bajocian and Oxfordian limestone was however similar with localized Zn-rich zones in the limestone cement and at the rim of oolites. The stratigraphic sporadicity and microscale heterogeneity of the Zn distribution together with the Zn speciation results point to a hydrothermal origin of Zn. Occurence of Zn-goethite is probably linked to the oxidative transformation of framboidal pyrite and hydrothermal sphalerite in contact with meteoritic waters. Difference in speciation between Bajocian limestone and Oxfordian limestone may be related to differences in rock permeability and/or to various hydrothermal events. Isotopic dating of the different mineralizations will be needed to decipher differences in Zn speciation and the precise chronology of hydrothermal episode
Interactions of ferrous iron with clay mineral surfaces during sorption and subsequent oxidation
In submerged soils and sediments, clay minerals are often exposed to anoxic waters containing ferrous iron (Fe2+). Here, we investigated the sorption of Fe2+ onto a synthetic montmorillonite (Syn-1) low in structural Fe (<0.05 mmol Fe per kg) under anoxic conditions and the effects of subsequent oxidation. Samples were prepared at two Fe-loadings (0.05 and 0.5 mol Fe added per kg clay) and equilibrated for 1 and 30 days under anoxic conditions (O2 < 0.1 ppm), followed by exposure to ambient air. Iron solid-phase speciation and mineral identity was analysed by 57Fe Mössbauer spectroscopy and synchrotron X-ray absorption spectroscopy (XAS). Mössbauer analyses showed that Fe(ii) was partially oxidized (14-100% of total added Fe2+) upon sorption to Syn-1 under anoxic conditions. XAS results revealed that the added Fe2+ mainly formed precipitates (layered Fe minerals, Fe(iii)-bearing clay minerals, ferrihydrite, and lepidocrocite) in different quantities depending on the Fe-loading. Exposing the suspensions to ambient air resulted in rapid and complete oxidation of sorbed Fe(ii) and the formation of Fe(iii)-phases (Fe(iii)-bearing clay minerals, ferrihydrite, and lepidocrocite), demonstrating that the clay minerals were unable to protect ferrous Fe from oxidation, even when equilibrated 30 days under anoxic conditions prior to oxidation. Our findings clarify the role of clay minerals in the formation and stability of Fe-bearing solid phases during redox cycles in periodically anoxic environments.ISSN:2050-7887ISSN:2050-789
Accuracy of chest radiographs in the emergency diagnosis of heart failure
The purpose of this study was to determine the diagnostic accuracy of chest radiographic findings of heart failure (HF) in current patients presenting with dyspnea in the emergency department. In a secondary analysis of the BASEL study, initial chest radiographs of 277 patients with acute dyspnea were evaluated by two radiologists blinded to the adjudicated diagnosis (56% had the final diagnosis of HF). Predefined radiographic criteria of HF were used. Statistical analysis included receiver-operating characteristic (ROC) analysis and calculation of a logistic regression model including B-type natriuretic peptide (BNP) levels. The reader's overall impression showed the highest area under the ROC curve for the diagnosis of HF in both supine and erect patient positions (0.855 and 0.857). Among individual radiographic findings, peribronchial cuffing in the supine position (0.829) showed the highest accuracies. The lowest accuracy was found for the vascular pedicle width in the supine position (0.461). Logistic regression analysis showed no significant differences between the reader's overall impression, the radiographic model, and BNP testing. In our study, the combination of radiographic features provided valuable information and was of comparable accuracy as BNP-testing for the diagnosis of H
The stress-inducible protein DRR1 exerts distinct effects on actin dynamics
Cytoskeletal dynamics are pivotal to memory, learning, and stress physiology, and thus psychiatric diseases. Downregulated in renal cell carcinoma 1 (DRR1) protein was characterized as the link between stress, actin dynamics, neuronal function, and cognition. To elucidate the underlying molecular mechanisms, we undertook a domain analysis of DRR1 and probed the effects on actin binding, polymerization, and bundling, as well as on actin-dependent cellular processes. METHODS: DRR1 domains were cloned and expressed as recombinant proteins to perform in vitro analysis of actin dynamics (binding, bundling, polymerization, and nucleation). Cellular actin-dependent processes were analyzed in transfected HeLa cells with fluorescence recovery after photobleaching (FRAP) and confocal microscopy. RESULTS: DRR1 features an actin binding site at each terminus, separated by a coiled coil domain. DRR1 enhances actin bundling, the cellular F-actin content, and serum response factor (SRF)-dependent transcription, while it diminishes actin filament elongation, cell spreading, and actin treadmilling. We also provide evidence for a nucleation effect of DRR1. Blocking of pointed end elongation by addition of profilin indicates DRR1 as a novel barbed end capping factor. CONCLUSIONS: DRR1 impacts actin dynamics in several ways with implications for cytoskeletal dynamics in stress physiology and pathophysiology
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Formation of Zn-rich phyllosilicate, Zn-layered double hydroxide and hydrozincite in contaminated calcareous soils
Recent studies demonstrated that Zn-phyllosilicate- and Zn-layered double hydroxide-type (Zn-LDH) precipitates may form in contaminated soils. However, the influence of soil properties and Zn content on the quantity and type of precipitate forming has not been studied in detail so far. In this work, we determined the speciation of Zn in six carbonate-rich surface soils (pH 6.2 to 7.5) contaminated by aqueous Zn in the runoff from galvanized power line towers (1322 to 30090 mg/kg Zn). Based on 12 bulk and 23 microfocused extended X-ray absorption fine structure (EXAFS) spectra, the number, type and proportion of Zn species were derived using principal component analysis, target testing, and linear combination fitting. Nearly pure Zn-rich phyllosilicate and Zn-LDH were identified at different locations within a single soil horizon, suggesting that the local availabilities of Al and Si controlled the type of precipitate forming. Hydrozincite was identified on the surfaces of limestone particles that were not in direct contact with the soil clay matrix. With increasing Zn loading of the soils, the percentage of precipitated Zn increased from {approx}20% to {approx}80%, while the precipitate type shifted from Zn-phyllosilicate and/or Zn-LDH at the lowest studied soil Zn contents over predominantly Zn-LDH at intermediate loadings to hydrozincite in extremely contaminated soils. These trends were in agreement with the solubility of Zn in equilibrium with these phases. Sequential extractions showed that large fractions of soil Zn ({approx}30% to {approx}80%) as well as of synthetic Zn-kerolite, Zn-LDH, and hydrozincite spiked into uncontaminated soil were readily extracted by 1 M NH{sub 4}NO{sub 3} followed by 1 M NH{sub 4}-acetate at pH 6.0. Even though the formation of Zn precipitates allows for the retention of Zn in excess to the adsorption capacity of calcareous soils, the long-term immobilization potential of these precipitates is limited
Coming down from the trees: is terrestrial activity in Bornean orangutans natural or disturbance driven?
The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated
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