71 research outputs found

    An Experimental Investigation of Electrical Conductivities in Biopolymers

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    Tuberculosis is a devastating infectious disease causing many deaths worldwide. Recent investigations have implicated neutrophil extracellular traps (NETs) in the host response to tuberculosis. The aim of the current study was to obtain evidence for NETs release in the circulation during human tuberculosis. For this we measured the plasma concentrations of nucleosomes in conjunction with neutrophil elastase, in 64 patients with active pulmonary tuberculosis and 32 healthy controls. Patients with active tuberculosis had elevated plasma levels of nucleosomes and elastase when compared with local healthy blood donors. Furthermore nucleosome and elastase levels showed a positive correlation. These findings provide the first evidence for the release of NETs in the circulation of patients with active pulmonary tuberculosis

    Graphene/α\alpha-RuCl3_3: An Emergent 2D Plasmonic Interface

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    Work function-mediated charge transfer in graphene/α\alpha-RuCl3_3 heterostructures has been proposed as a strategy for generating highly-doped 2D interfaces. In this geometry, graphene should become sufficiently doped to host surface and edge plasmon-polaritons (SPPs and EPPs, respectively). Characterization of the SPP and EPP behavior as a function of frequency and temperature can be used to simultaneously probe the magnitude of interlayer charge transfer while extracting the optical response of the interfacial doped α\alpha-RuCl3_3. We accomplish this using scanning near-field optical microscopy (SNOM) in conjunction with first-principles DFT calculations. This reveals massive interlayer charge transfer (2.7 ×\times 1013^{13} cm2^{-2}) and enhanced optical conductivity in α\alpha-RuCl3_3 as a result of significant electron doping. Our results provide a general strategy for generating highly-doped plasmonic interfaces in the 2D limit in a scanning probe-accessible geometry without need of an electrostatic gate.Comment: 22 pages, 5 figure

    Moiré nematic phase in twisted double bilayer graphene

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    Graphene moiré superlattices display electronic flat bands. At integer fillings of these flat bands, energy gaps due to strong electron–electron interactions are generally observed. However, the presence of other correlation-driven phases in twisted graphitic systems at non-integer fillings is unclear. Here, we report the existence of three-fold rotational (C3) symmetry breaking in twisted double bilayer graphene. Using spectroscopic imaging over large and uniform areas to characterize the direction and degree of C3 symmetry breaking, we find it to be prominent only at energies corresponding to the flat bands and nearly absent in the remote bands. We demonstrate that the magnitude of the rotational symmetry breaking does not depend on the degree of the heterostrain or the displacement field, being instead a manifestation of an interaction-driven electronic nematic phase. We show that the nematic phase is a primary order that arises from the normal metal state over a wide range of doping away from charge neutrality. Our modelling suggests that the nematic instability is not associated with the local scale of the graphene lattice, but is an emergent phenomenon at the scale of the moiré lattice.S.T. and A.N.P. acknowledge funding from Programmable Quantum Materials, an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award no. DE-SC0019443. STM equipment support (A.N.P.) and 2D sample synthesis (Y.S.) were provided by the Air Force Office of Scientific Research via grant no. FA9550-16-1-0601. C.R.-V. acknowledges funding from the European Union Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreement no. 844271. A.R. acknowledges funding by the European Research Council (ERC-2015-AdG-694097), Grupos Consolidados (IT1249-19) and the Flatiron Institute, a division of the Simons Foundation. L.K., D.M.K. and A.R. acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG) under Germany’s Excellence Strategy-Cluster of Excellence Matter and Light for Quantum Computing (ML4Q) EXC 2004/1-390534769 and Advanced Imaging of Matter (AIM) EXC 2056−390715994 and funding by the Deutsche Forschungsgemeinschaft (DFG) under RTG 1995, within the Priority Program SPP 2244 ‘2DMP’ and GRK 2247. A.R. acknowledges support by the Max Planck Institute-New York City Center for Non-Equilibrium Quantum Phenomena. H.O. is supported by the NSF MRSEC programme grant no. DMR-1420634. Tight-binding and fRG simulations were performed with computing resources granted by RWTH Aachen University under projects rwth0496 and rwth0589. R.S. and M.S.S. acknowledge support from the National Science Foundation under grant no. DMR-2002850. R.M.F. was supported by the DOE-BES under award no. DE-SC0020045. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan (grant no. JPMXP0112101001), JSPS KAKENHI (grant no. JP20H00354) and the CREST (grant no. JPMJCR15F3) JST.Peer reviewe

    Evidence for perinatal and child health care guidelines in crisis settings: can Cochrane help?

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    <p>Abstract</p> <p>Background</p> <p>It is important that healthcare provided in crisis settings is based on the best available research evidence. We reviewed guidelines for child and perinatal health care in crisis situations to determine whether they were based on research evidence, whether Cochrane systematic reviews were available in the clinical areas addressed by these guidelines and whether summaries of these reviews were provided in Evidence Aid.</p> <p>Methods</p> <p>Broad internet searches were undertaken to identify relevant guidelines. Guidelines were appraised using AGREE and the clinical areas that were relevant to perinatal or child health were extracted. We searched The Cochrane Database of Systematic Reviews to identify potentially relevant reviews. For each review we determined how many trials were included, and how many were conducted in resource-limited settings.</p> <p>Results</p> <p>Six guidelines met selection criteria. None of the included guidelines were clearly based on research evidence. 198 Cochrane reviews were potentially relevant to the guidelines. These reviews predominantly addressed nutrient supplementation, breastfeeding, malaria, maternal hypertension, premature labour and prevention of HIV transmission. Most reviews included studies from developing settings. However for large portions of the guidelines, particularly health services delivery, there were no relevant reviews. Only 18 (9.1%) reviews have summaries in Evidence Aid.</p> <p>Conclusions</p> <p>We did not identify any evidence-based guidelines for perinatal and child health care in disaster settings. We found many Cochrane reviews that could contribute to the evidence-base supporting future guidelines. However there are important issues to be addressed in terms of the relevance of the available reviews and increasing the number of reviews addressing health care delivery.</p

    Fatal outcome of Bacillus cereus septicaemia

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    Bacillus cereus is a ubiquitous environmental micro-organism which is often a contaminant of clinical cultures. Infections due to B. cereus are described, but mostly in immunocompromised patients. We report a fatal outcome of B. cereus septicaemia in an immunocompetent patient with a mechanical mitral valv

    Efficacy and safety of ceftaroline: systematic review and meta-analysis

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    Background: Resistance to antibiotics is steadily increasing. Ceftaroline has a broad spectrum of activity against clinically relevant gram-positive strains including methicillin-resistant Staphylococcus aureus . Objectives: This systematic review was conducted to evaluate whether ceftaroline is effective and safe, leading to a lower rate of treatment failures than comparators. Material and methods: Studies were included if they were comparing the efficacy and safety of ceftaroline with other antibiotics. Data sources: Using the search terms ‘ceftaroline’ or ‘ceftaroline fosamil’, a search strategy was developed. The efficacy endpoint was the rate of treatment failure, while the safety endpoint was the incidence of adverse events. Heterogeneity bias was estimated using the Q -test, and publication bias was estimated using Egger’s test. Null hypothesis was rejected if p value was less than 0.05. Results: Only 10 studies were included. Synthesis of results: The risk of treatment failure was significantly lower for ceftaroline than for comparators, and cumulative meta-analysis showed that the effect size was relevant and precise. Pooled risk ratio was 0.79 (95% confidence interval = 0.65–0.95). The rates of adverse events were similar among the studies, and there were no statistically significant differences between groups. For this endpoint, there was a significant heterogeneity among studies ( p  = 0.03). Pooled risk ratio for adverse events was 0.98 (95% confidence interval = 0.87–1.10), without a statistical difference. Discussion: The risk of treatment failure was significantly lower for ceftaroline than comparators, while the rate of adverse events was similar. To the best of our knowledge, this is the first systematic review on the efficacy and safety of ceftaroline including children and adults. A limitation is that no randomized controlled trials were found in non-complicated skin- and soft-tissue infection and non-community-acquired pneumonia infections; only few cases with methicillin-resistant Staphylococcus aureus isolations and no patients admitted to the intensive care unit were evaluated. Interpretation: Ceftaroline may be an option of treatment in complicated skin- and soft-tissue infection and community-acquired pneumonia

    Herpes Zoster after COVID-vaccination

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    COVID-19 presents in various ways, but mainly as a pulmonary disease (Marzano, 2020). Skin manifestations have been reported, including reactivation of the varicella-zoster virus (Marzano, 2020). Our case report describes two adults developing herpes zoster after vaccination with tozinameran (the Pfizer-BioNTech COVID-19 mRNA vaccine). A possible cause for this reaction is a transient lymphocytopenia that occurs after the vaccination — similar to that in COVID-19 disease (Mulligan, 2020; Wang, 2020; Qin, 2020; Brabilla, 2020; Wang, 2020; Wei, 2017). In the context of vaccinating older and/or immunocompromised adults, our observations can be the starting point for further evaluation of a possible relationship between COVID-19, COVID vaccines, and herpes zoster
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