166 research outputs found

    Room temperature demonstration of a sodium superionic conductor with grain conductivity in excess of 0.01 S cm-1 and its primary applications in symmetric battery cells

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    Partial financial support from the German Federal Ministry of Education and Research (BMBF) in the frame of the BenchBatt project (reference number 03XP0047B) is gratefully acknowledged.The lack of suitable candidate electrolyte materials for practical application limits development of all-solid-state Na-ion batteries. Na3+xZr2Si2+xP1-xO12 were the very first series of NASICONs discovered some 40 years ago; however, separation of bulk conductivity from total conductivity at room temperature is still problematic. It has been suggested that the effective Na-ion conductivity is ~10-4 S cm-1 at room temperature for Na3+xZr2Si2+xP1-xO12 ceramics; however using solution-assisted solid-state reaction for preparation of Na3+xZr2Si2+xP1-xO12, total conductivity of 5 × 10-3 S cm-1 was achieved for Na3.4Zr2Si2.4P0.6O12 at 25 °C, higher than previously reported for polycrystalline Na-ion conductors. Bulk conductivity of 1.5 × 10-2 S cm-1 was revealed by high frequency impedance spectroscopy (up to 3 GHz) and verified by low temperature impedance spectroscopy (down to -100 °C) for Na3.4Zr2Si2.4P0.6O12 at 25 °C, indicating further potential of increasing the related total conductivity. A Na/Na3.4Zr2Si2.4P0.6O12/Na symmetric cell showed low interface resistance and high cycling stability at room temperature. A full-ceramic cell was fabricated and tested at 28 °C with good cycling performance.PostprintPeer reviewe

    Coexistence of aneurysmal subarachnoid hemorrhage and surgically identified pituitary apoplexy: a case report and review of the literature

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    INTRODUCTION: A ruptured aneurysm associated with a pituitary apoplexy is rare. We present the first case report of the coexistence of a ruptured posterior communicating aneurysm with a surgically discovered pituitary apoplexy where the pituitary apoplexy had not been diagnosed by a pre-operative computerized tomography scan. CASE PRESENTATION: A 31-year-old right-handed Chinese woman began to experience severe headache, vomiting and blurred vision which continued for two days. On admission to the hospital, a brain computerized tomography scan demonstrated a small amount of increased signal in the basal cisterns; no evidence of intrasellar and suprasellar lesions was seen. The appearance of her brain suggested aneurysmal subarachnoid hemorrhage. She had nuchal rigidity and reduced vision. There was no extra-ocular palsy and no other neurological deficit. Our patient had no stigmata of Cushing’s syndrome or acromegaly. During an interview for further history, she reported normal menses and denied reduced vision. Cerebral digital subtraction angiography was subsequently performed, which revealed a 6mm left posterior communicating aneurysm. Urgent left pterional craniotomy was performed. The left ruptured posterior communicating artery aneurysm was completely dissected prior to clipping. At surgery, a suprasellar mass was discovered, the tumor bulging the diaphragma sella and projecting anteriorly under the chiasm raising suspicion of a pituitary tumor. The anterior part of the tumor capsule was opened and a necrotic tumor mixed with dark old blood was removed. The appearance suggested pituitary apoplexy. Histopathology revealed pituitary adenoma with evidence of hemorrhagic necrosis. Our patient made a good recovery. CONCLUSION: Our case report proves that pituitary apoplexy can be coexistent with the rupture of a posterior communicating aneurysm. This association should be considered when evaluating any case of aneurysm. A normal computerized tomography scan does not exclude pituitary apoplexy. Pre-operative magnetic resonance imaging interpretation is required if a pituitary apoplexy is suspected. Craniotomy allows a coexisting aneurysm and pituitary apoplexy to be simultaneously treated

    Composition-Tuned Pt-Skinned PtNi Bimetallic Clusters as Highly Efficient Methanol Dehydrogenation Catalysts

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    Platinum is the most active anode and cathode catalyst in next-generation fuel cells using methanol as liquid source of hydrogen. Its catalytic activity can be significantly improved by alloying with 3d metals, although a precise tuning of its surface architecture is still required. Herein, we report the design of a highly active low-temperature (below 0 °C) methanol dehydrogenation anode catalyst with reduced CO poisoning based on ultralow amount of precisely defined PtxNi1–x (x = 0 to 1) bimetallic clusters (BCs) deposited on inert flat oxides by cluster beam deposition. These BCs feature clear composition-dependent atomic arrangements and electronic structures stemming from their nucleation mechanism, which are responsible for a volcano-type activity trend peaking at the Pt0.7Ni0.3 composition. Our calculations reveal that at this composition, a cluster skin of Pt atoms with d-band centers downshifted by subsurface Ni atoms weakens the CO interaction that in turn triggers a significant increase in the methanol dehydrogenation activity

    Atomic Insights into Aluminium-Ion Insertion in Defective Anatase for Batteries

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    International audienceAluminium batteries constitute a safe and sustainable high‐energy‐density electrochemical energy‐storage solution. Viable Al‐ion batteries require suitable electrode materials that can readily intercalate high‐charge Al3+ ions. Here, we investigate the Al3+ intercalation chemistry of anatase TiO2 and how chemical modifications influence the accommodation of Al3+ ions. We use fluoride‐ and hydroxide‐doping to generate high concentrations of titanium vacancies. The coexistence of these hetero‐anions and titanium vacancies leads to a complex insertion mechanism, attributed to three distinct types of host sites: native interstitial sites, single vacancy sites, and paired vacancy sites. We demonstrate that Al3+ induces a strong local distortion within the modified TiO2 structure, which affects the insertion properties of the neighbouring host sites. Overall, specific structural features induced by the intercalation of highly polarising Al3+ ions should be considered when designing new electrode materials for polyvalent batteries

    Cluster Beam Deposition of Ultrafine Cobalt and Ruthenium Clusters for Efficient and Stable Oxygen Evolution Reaction

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    Ultrafine cobalt and ruthenium clusters are deposited on carbon paper substrates by cluster beam deposition using a matrix assembly cluster source and a pulsed microplasma cluster source, respectively. When used to catalyze the oxygen evolution reaction (OER), the cobalt and ruthenium clusters show electrocatalytic performance superior to the state-of-the-art Ru/C and RuO2 nanoparticle catalysts on both a mass and a specific-surface-area basis. Typically, the cobalt clusters can deliver 10 mA cm–2 at a low overpotential of 320 mV and show a small Tafel slope of 50 mV dec–1 and a mass-based turnover frequency of 0.01 s–1 at an overpotential of 300 mV, outperforming many cobalt-based OER catalysts

    A Novel Nanobody Specific for Respiratory Surfactant Protein A has Potential for Lung Targeting

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    Lung-targeting drugs are thought to be potential therapies of refractory lung diseases by maximizing local drug concentrations in the lung to avoid systemic circulation. However, a major limitation in developing lung-targeted drugs is the acquirement of lung-specific ligands. Pulmonary surfactant protein A (SPA) is predominantly synthesized by type II alveolar epithelial cells, and may serve as a potential lung-targeting ligand. Here, we generated recombinant rat pulmonary SPA (rSPA) as an antigen and immunized an alpaca to produce two nanobodies (the smallest naturally occurring antibodies) specific for rSPA, designated Nb6 and Nb17. To assess these nanobodies\u27 potential for lung targeting, we evaluated their specificity to lung tissue and toxicity in mice. Using immunohistochemistry, we demonstrated that these anti-rSPA nanobodies selectively bound to rat lungs with high affinity. Furthermore, we intravenously injected fluorescein isothiocyanate-Nb17 in nude mice and observed its preferential accumulation in the lung to other tissues, suggesting high affinity of the nanobody for the lung. Studying acute and chronic toxicity of Nb17 revealed its safety in rats without causing apparent histological alterations. Collectively, we have generated and characterized lung-specific nanobodies, which may be applicable for lung drug delivery

    Boosting Photoelectrochemical Water Oxidation of Hematite in Acidic Electrolytes by Surface State Modification

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    State-of-the-art water-oxidation catalysts (WOCs) in acidic electrolytes usually contain expensive noble metals such as ruthenium and iridium. However, they too expensive to be implemented broadly in semiconductor photoanodes for photoelectrochemical (PEC) water splitting devices. Here, an Earth-abundant CoFe Prussian blue analogue (CoFe-PBA) is incorporated with core-shell FeO/FeTiO type II heterojunction nanowires as composite photoanodes for PEC water splitting. Those deliver a high photocurrent of 1.25 mA cm at 1.23 V versus reversible reference electrode in acidic electrolytes (pH = 1). The enhancement arises from the synergic behavior between the successive decoration of the hematite surface with nanolayers of FeTiO and then, CoFe-PBA. The underlying physical mechanism of performance enhancement through formation of the FeO/FeTiO/CoFe-PBA heterostructure reveals that the surface states' electronic levels of hematite are modified such that an interfacial charge transfer becomes kinetically favorable. These findings open new pathways for the future design of cheap and efficient hematite-based photoanodes in acidic electrolytes

    The accelerated scaling attractor solution of the interacting agegraphic dark energy in Brans-Dicke theory

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    We investigate the interacting agegraphic dark energy in Brans-Dicke theory and introduce a new series general forms of dark sector coupling. As examples, we select three cases involving a linear interaction form (Model I) and two nonlinear interaction form (Model II and Model III). Our conclusions show that the accelerated scaling attractor solutions do exist in these models. We also find that these interacting agegraphic dark energy modes are consistent with the observational data. The difference in these models is that nonlinear interaction forms give more approached evolution to the standard Λ\LambdaCDM model than the linear one. Our work implies that the nonlinear interaction forms should be payed more attention.Comment: 9 pages, 10 figures, accepted in Eur. Phys. J.

    Genomewide association study of leprosy.

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    BACKGROUND: The narrow host range of Mycobacterium leprae and the fact that it is refractory to growth in culture has limited research on and the biologic understanding of leprosy. Host genetic factors are thought to influence susceptibility to infection as well as disease progression. METHODS: We performed a two-stage genomewide association study by genotyping 706 patients and 1225 controls using the Human610-Quad BeadChip (Illumina). We then tested three independent replication sets for an association between the presence of leprosy and 93 single-nucleotide polymorphisms (SNPs) that were most strongly associated with the disease in the genomewide association study. Together, these replication sets comprised 3254 patients and 5955 controls. We also carried out tests of heterogeneity of the associations (or lack thereof) between these 93 SNPs and disease, stratified according to clinical subtype (multibacillary vs. paucibacillary). RESULTS: We observed a significant association (P<1.00x10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, and RIPK2 and a trend toward an association (P=5.10x10(-5)) with a SNP in LRRK2. The associations between the SNPs in C13orf31, LRRK2, NOD2, and RIPK2 and multibacillary leprosy were stronger than the associations between these SNPs and paucibacillary leprosy. CONCLUSIONS: Variants of genes in the NOD2-mediated signaling pathway (which regulates the innate immune response) are associated with susceptibility to infection with M. leprae

    Towards a global One Health index: a potential assessment tool for One Health performance

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    BACKGROUND: A One Health approach has been increasingly mainstreamed by the international community, as it provides for holistic thinking in recognizing the close links and inter-dependence of the health of humans, animals and the environment. However, the dearth of real-world evidence has hampered application of a One Health approach in shaping policies and practice. This study proposes the development of a potential evaluation tool for One Health performance, in order to contribute to the scientific measurement of One Health approach and the identification of gaps where One Health capacity building is most urgently needed. METHODS: We describe five steps towards a global One Health index (GOHI), including (i) framework formulation; (ii) indicator selection; (iii) database building; (iv) weight determination; and (v) GOHI scores calculation. A cell-like framework for GOHI is proposed, which comprises an external drivers index (EDI), an intrinsic drivers index (IDI) and a core drivers index (CDI). We construct the indicator scheme for GOHI based on this framework after multiple rounds of panel discussions with our expert advisory committee. A fuzzy analytical hierarchy process is adopted to determine the weights for each of the indicators. RESULTS: The weighted indicator scheme of GOHI comprises three first-level indicators, 13 second-level indicators, and 57 third-level indicators. According to the pilot analysis based on the data from more than 200 countries/territories the GOHI scores overall are far from ideal (the highest score of 65.0 out of a maximum score of 100), and we found considerable variations among different countries/territories (31.8–65.0). The results from the pilot analysis are consistent with the results from a literature review, which suggests that a GOHI as a potential tool for the assessment of One Health performance might be feasible. CONCLUSIONS: GOHI—subject to rigorous validation—would represent the world’s first evaluation tool that constructs the conceptual framework from a holistic perspective of One Health. Future application of GOHI might promote a common understanding of a strong One Health approach and provide reference for promoting effective measures to strengthen One Health capacity building. With further adaptations under various scenarios, GOHI, along with its technical protocols and databases, will be updated regularly to address current technical limitations, and capture new knowledge. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40249-022-00979-9
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