482 research outputs found

    Raman cross section of spin ladders

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    We demonstrate that a two-triplet resonance strongly renormalizes the Raman spectrum of two-leg spin ladders and moreover suggest this to be the origin of the asymmetry of the magnetic Raman continuum observed in CaV2O5.Comment: 2 pages, 1 figur

    Patient reported burden of asthma on resource use and productivity across 11 countries in europe

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    ACKNOWLEDGMENTS Sponsorship for this study and article processing charges were funded by Mundipharma International Limited (Cambridge, UK). All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship of this manuscript, take responsibility for the integrity of the work as a whole, and have given final approval to the version to be published. We thank Emily Taylor, Incite Marketing Planning Limited (London, UK) for assistance in data analysis and Caoimhe McKerr (Adelphi Values, Bollington, UK) for editorial assistance. Support for this assistance was funded by Mundipharma International Limited. Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Peer reviewedPublisher PD

    Initial interaction of citrate-coated iron oxide nanoparticles with the glycocalyx of THP-1 monocytes assessed by real-time magnetic particle spectroscopy and electron microscopy

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    Interaction with biological material can alter physicochemical parameters of magnetic nanoparticles and might thereby change their magnetic behavior with potentially important implications for various nanoparticle applications. Little is known about changes of the magnetic behavior that occur during the initial phase of cell binding and uptake. We investigate the magnetic behavior of very small superparamagnetic iron-oxide nanoparticles (VSOP) during initial contact with THP-1 monocytes. We combine real-time magnetic particle spectroscopy (MPS), a fast and sensitive method for specific detection of magnetic nanoparticles in biological specimen with high-pressure-freezing/freeze-substitution transmission electron microscopy (HPF/FS-TEM), enabling us to generate snapshots of the interaction of VSOP with the cellular glycocalyx. MPS reveals significant changes of the dynamic magnetic behavior within seconds after VSOP injection into monocyte suspensions that correlate with the formation of nanoparticle clusters in the glycocalyx. The combination of real-time MPS and HPF/FS-TEM provides an ideal platform to analyze magnetic behaviors of nanoparticles upon interaction with cells and tissues

    Characterization of the Interfaces in LiFePO4/PEO-LiTFSI Composite Cathodes and to the Adjacent Layers

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    Interface resistances between the different components of battery cells limit their fast charge and discharge capability which is required for different applications such as electromobility. To decrease interface resistances, it is necessary to understand which individual interface they arise at and how they can be controlled. Electrochemical impedance spectroscopy is a well-established technique for the distinction of different contributions to the internal cell resistance and allows the characterization of interface resistances. Especially the use of suitable cell setups allows one to attribute the measured resistances to specific interfaces. In this contribution, we investigate the impedance of dry polymer full cells containing a lithium iron phosphate/ poly(ethylene oxide)-lithium bis(trifluoromethanesulfonyl)imide composite cathode, a solid polymer electrolyte separator and a lithium-metal anode. Based on the results on different cell setups, we are able to reliably determine the planar resistances between the components as well as the charge transfer resistance inside the composite cathode. For unoptimized systems, we find high planar resistances, which can be significantly reduced by coating and processing strategies. For the charge transfer resistance, we find a dependence on the SOC as well as on the charging direction. Possible mechanisms for the evolution of interface resistances are discussed also based on chemical analysis performed by photoelectron spectroscopy (XPS)

    Macrophage uptake switches on OCT contrast of superparamagnetic nanoparticles for imaging of atherosclerotic plaques

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    Background: Optical coherence tomography (OCT) is an intravascular, high-resolution imaging technique that is used to characterize atherosclerotic plaques. However, the identification of macrophages as important markers of inflammation and plaque vulnerability remains difficult. Here, we investigate whether the uptake of very small iron oxide particles (VSOP) in macrophages, that cluster in phagolysosomes and allow high-quality magnetic resonance imaging (MRI) of atherosclerotic plaques, and uptake of ferumoxytol nanoparticles enhance detection of macrophages by OCT. Materials and methods: RAW 264.7 macrophage cells were incubated with VSOP (1 and 2 mM Fe) that have been clinically tested and ferumoxytol (8.9 mM Fe) that is approved for iron deficiency treatment and currently investigated as an MRI contrast agent. The light scattering of control macrophages, nanoparticle-labeled macrophages (2,000,000 in 500 mu L) and nanoparticle suspensions was measured in synchronous wavelength scan mode using a fluorescence spectrophotometer. For OCT analyses, pellets of 8,000,000 non-labeled, VSOP-labeled and ferumoxytol-labeled RAW 264.7 macrophages were imaged and analyzed on an OPTIS (TM) OCT imaging system. Results: Incubation with 1 and 2 mM VSOP resulted in uptake of 7.1 +/- 1.5 and 12 +/- 1.5 pg Fe per cell, which increased the backscattering of the macrophages in spectrophotometry 2.5- and 3.6-fold, whereas incubation with 8.9 mM Fe ferumoxytol resulted in uptake of 6.6 +/- 2 pg Fe per cell, which increased the backscattering 1.5-fold at 700 nm. In contrast, backscattering of non-clustered nanoparticles in suspension was negligible. Accordingly, OCT imaging could visualize significantly increased backscattering and signal attenuation of nanoparticle-labeled macrophages in comparison with controls. Conclusion: We conclude that VSOP and, to a lesser extent, ferumoxytol increase light scattering and attenuation when taken up by macrophages and can serve as a multimodal imaging probe for MRI and OCT to improve macrophage detection in atherosclerotic plaques by OCT in the future

    Latent infection of human bocavirus accompanied by flare of chronic cough, fatigue and episodes of viral replication in an immunocompetent adult patient, cologne, Germany

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    Publisher Copyright: © 2016 The Authors.Introduction: The human bocavirus (HBoV) is a parvovirus and is associated with mild to lifethreatening acute or persisting respiratory infections, frequently accompanied by further pathogens. So far, there is limited knowledge on the mechanisms of persistence, and no reports on chronic infections or latency have been published so far. Case presentation: An immunocompetent male patient suffers from a chronic HBoV1 infection, i.e. viral DNA was detected in both serum and bronchoalveolar lavage (BAL) for >5 months without co-infections and with respiratory symptoms resolved spontaneously while receiving symptomatic treatment with montelukast and corticosteroids. Following the symptomatic medication of a chronic infection with HBoV1 viraemia indicating active viral replication lasting over 5 months, the patient cleared the viraemia and no further viral DNA was detectable in the BAL. However, by fluorescence in situ hybridization analyses of mucosal biopsies, it was shown that the virus genome still persisted in the absence of viral shedding but in a more compact manner possibly representing a supercoiled episomal form of this otherwise linear singlestranded DNA genome. This indicated the entry into a latency phase. Moreover, the cytokine profile and the IP-10/TARC ratio, a marker for fibrotization, seem to have been altered by HBoV1 replication. Although specific IgG antibodies were detectable during the whole observation period, they showed an apparently insufficient neutralising activity. Conclusion: On the one hand, these findings suggest that the symptomatic medication may have led to clearance of the virus from blood and airways and, moreover, that the viral DNA persists in the tissue as an altered episomal form favoured by lacking neutralising antibodies. This appears to be important in order to reduce possible long-term effects such as lung fibrosis.publishersversionPeer reviewe

    Linked (Open) Data - Bibliographische Daten im Semantic Web

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    Linked (Open) Data - bibliographic data on the Semantic Web. Report of the Working Group on Linked Data to the plenary assembly of the Austrian Library Network (translation of the title). Linked Data stands for a certain approach to publishing data on the Web. The underlying idea is to harmonise heterogeneous data sources of different origin in order to improve their accessibility and interoperability, effectively making them queryable as a big distributed database. This report summarises relevant developments in Europe as well as the Linked Data Working Group‘s strategic and technical considerations regarding the publishing of the Austrian Library Network’s (OBV’s) bibliographic datasets. It concludes with the mutual agreement that the implementation of Linked Data principles within the OBV can only be taken into consideration accompanied by a discussion about the provision of the datasets under a free license.Linked Data steht für eine bestimmte Form der Veröffentlichung von Daten via Internet. Die zu Grunde liegende Idee ist es, Daten verschiedenster Provenienz, die derzeit teilweise gar nicht oder nur schwer zugänglich sind, in möglichst einheitlicher Form miteinander zu verknüpfen und dadurch in ihrer Gesamtheit abfragbar zu machen. Dieser Bericht fasst die Entwicklungen im europäischen Raum, sowie strategische und technische Überlegungen der AG Linked Data hinsichtlich der Veröffentlichung von bibliothekarischen Daten des Österreichischen Bibliothekenverbundes (OBV) zusammen und schließt mit der gemeinsamen Übereinkunft, dass die Umsetzung von Linked Data-Prinzipien im OBV nur in Zusammenhang mit einer Diskussion über die damit einhergehende Veröffentlichung der Daten unter einer freien Lizenz angedacht werden sollte

    Origin and pathogenesis of nodular lymphocyte–predominant Hodgkin lymphoma as revealed by global gene expression analysis

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    The pathogenesis of nodular lymphocyte–predominant Hodgkin lymphoma (NLPHL) and its relationship to other lymphomas are largely unknown. This is partly because of the technical challenge of analyzing its rare neoplastic lymphocytic and histiocytic (L&H) cells, which are dispersed in an abundant nonneoplastic cellular microenvironment. We performed a genome-wide expression study of microdissected L&H lymphoma cells in comparison to normal and other malignant B cells that indicated a relationship of L&H cells to and/or that they originate from germinal center B cells at the transition to memory B cells. L&H cells show a surprisingly high similarity to the tumor cells of T cell–rich B cell lymphoma and classical Hodgkin lymphoma, a partial loss of their B cell phenotype, and deregulation of many apoptosis regulators and putative oncogenes. Importantly, L&H cells are characterized by constitutive nuclear factor {kappa}B activity and aberrant extracellular signal-regulated kinase signaling. Thus, these findings shed new light on the nature of L&H cells, reveal several novel pathogenetic mechanisms in NLPHL, and may help in differential diagnosis and lead to novel therapeutic strategies

    Exploring the mechanical character of molybdenum grain boundaries via nanoindentation and three-point-bending

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    The interactions of interfaces with dislocations have been extensively studied in the past. Still, there is a lack of high throughput methods, which can potentially be used for systematic studies to cover a wide range of grain boundary types. Nanoindentation offers the opportunity to combine a high spatial resolution with high effectiveness, thus enabling to obtain comprehensive mechanical data in the vicinity of grain boundaries. The present study on coarse-grained molybdenum will show results of mechanical property mapping near grain boundaries. Here, for the first time also the indenter tip rotation angle with respect to the loading axis as well as the grain orientation are considered. Results will show that neglecting these parameters can bias interpretations of the interface/dislocation interactions, as the localized deformation paths around the indentation are thereby significantly changed. Systematic experiments on commercially pure, recrystallized molybdenum have been performed to investigate the dependence of the hardness increase near grain boundaries with respect to the boundary misorientation angle. As a complementary method, three-point-bending is applied on mm-sized specimens until individual grain boundaries delaminate, which in turn will be identified and cross-checked with findings of the nanoindentation tests. Doping molybdenum with elements like carbon and/or boron is known to suppress intercrystalline failure. For this reason, the presented grain boundary characterization methods will be applied to extract mechanical changes caused by these doping elements
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