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[en] Here in this paper we report an IR-IR double resonance study of the structural landscape present in the Na+(glucose) complex. Our experimental approach involves minimal modifications to a typical IR predissociation setup, and can be carried out via ion-dip or isomer-burning methods, providing additional flexibility to suit different experimental needs. In the current study, the single-laser IR predissociation spectrum of Na+(glucose), which clearly indicates contributions from multiple structures, was experimentally disentangled to reveal the presence of three α-conformers and five β-conformers. Comparisons with calculations show that these eight conformations correspond to the lowest energy gas-phase structures with distinctive Na+ coordination.
[en] A series of naturally occurring cardenolides that exhibit potent anti-transmissible gastroenteritis virus (TGEV) activity in swine testicular (ST) cells has been identified. In an immunofluorescence assay, these cardenolides were found to diminish the expressions of TGEV nucleocapsid and spike protein, which was used as an indication for viral replication; block TGEV infection induced apoptosis and cytopathic effects; and impart the same trend of inhibitory activity against Na+/K+-ATPase as for anti-TGEV activity. The viral titer inhibition was found to take place in a dose-dependent manner. Knocking down expression of Na+/K+-ATPase, the cellular receptor of cardenolides, in ST cells was found to significantly impair the susceptibility of ST cells to TGEV infectivity. Thus, we have identified Na+/K+-ATPase as an anti-viral drug target and its antagonists, cardenolides, a novel class of anti- TGEV agents. - Highlights: • Cardenolides were identified as a novel class of anti-TGEV agents. • Cardenolides diminished TGEV replication/viral titers in a dose dependent manner. • Cardenolides blocked TGEV infection induced apoptosis and cytopathic effect. • These cardenolides imparted the same trend of inhibitory activity for Na+/K+-ATPase. • Na+/K+-ATPase was identified as an anti-viral drug target.
[en] Highlights: • Seven Sleeping Beauties were identified in Paul Hagenmuller's work. • Sleeping Beauties are papers with delayed recognition in terms of citations. • The Sleeping Beauties relate to work on silicon clathrate, sodium cobaltate, and sodium-ion battery research. • The occurrence of Sleeping Beauties challenges the use of short-term citation-based metrics for the evaluation of scientific impact. - Abstract: Paul Hagenmuller (1921−2017) is an important figure of French solid-state chemistry, who enjoyed scientific and institutional recognition. He published 796 papers and has been cited more than 16,000 times. This paper explores Hagenmuller's work using scientometric analysis to reveal the impact of his work, his main research topics and his collaborations. Although Hagenmuller was a recognized scientist, a subset of his work, now highly cited, attracted little attention at the time of publication. To understand this phenomenon, we detect and study papers with delayed recognition, also called 'Sleeping Beauties' (SBs). In scientometrics, SBs are publications that go unnoticed, or 'sleep' for a long time before suddenly attracting a lot of attention in terms of citations. We identify 7 SBs published between 1965 and 1985, and awakened between 1993 and 2010. The first SB reports the discovery of the clathrate structure of silicon. The second reports the isolation of four new phases with the formula NaxCoO2 (x < =1). The five other SBs investigate the electrochemical intercalation and deintercalation of sodium, and the structure and properties of layered oxides. Through interviews with his coworkers, we attempt to identify the reasons for the delayed recognition and the context of the renewed interest in those papers.
[en] A sodium ion- selective electrode based on dibenzopyridino-18-crown-6 as membrane carrier was successfully prepared. The electrode exhibits a Nernstian response for Na"+ ions within the concentration range of 1.0 x 10"-"4-1.0 x 10"-"1 M. The response time of the sensor is 20 s. The sodium ion-selective electrode exhibited comparatively good selectivities with respect to alkali, alkaline earth and some transition metal ions
[en] As a novel Na-ion battery anode, we studied electrochemical reactions of a LaSn3 electrode, and evaluated its cycling performance by comparison with that of a SmSn3 electrode. The LaSn3 electrode showed a reversible capacity of 580 mA h cm−3 at the first cycle, and a gradual increase in the capacity with cycling number. The LaSn3 electrode exhibited a high capacity of 1470 mA h cm−3 even at the 400th cycle, which is three times higher than that of a hard carbon electrode. The electrode reactions of elemental Sn were observed in a cyclic voltammetry profile of the LaSn3 electrode, indicating that a phase separation of LaSn3 gradually occurs to form Sn. We suggested that the phase separation provides a Na-inactive La3Sn5 matrix, which can suppress the aggregation of Sn particles and can improve the cyclability. On the other hand, the SmSn3 electrode showed a higher initial capacity of 970 mA h cm−3 and an earlier capacity decay by the 200th cycle. It is suggested that the phase separation of SmSn3 progresses more rapidly while that of LaSn3 slowly occurs because of a higher thermodynamic stability for LaSn3 than SmSn3.
[en] Sodium (Na)-ion batteries (NIBs) are considered promising alternative candidates to the well-commercialized lithium-ion batteries, especially for applications in large-scale energy storage systems. The electrochemical performance of NIBs such as the cyclability, rate capability, and voltage profiles are strongly dependent on the structural and morphological evolution, phase transformation, sodium-ion diffusion, and electrode/electrolyte interface reconstruction during charge–discharge cycling. Therefore, in-depth understanding of the structure and kinetics of electrode materials and the electrode/electrolyte interfaces is essential for optimizing current NIB systems and exploring new materials for NIBs. Recently, rapid progress and development in spectroscopic, microscopic, and scattering techniques have provided extensive insight into the nature of structural evolution, morphological changes of electrode materials, and electrode/electrolyte interface in NIBs. Here in this review, a comprehensive overview of both static (ex situ) and real-time (in situ or in operando) techniques for studying the NIBs is provided. Lastly, special focus is placed on how these techniques are applied to the fundamental investigation of NIB systems and what important results are obtained.
[en] Complete text of publication follows. Zinc is one of the essential metals, but high amounts of zinc induce several kinds of tissue damage. In those tissues, pancreatic exocrine cells are very sensitive to zinc, but the cause is still unclear. When 600 μM of zinc was added to AR42J cells, necrosis, but not apoptosis, quickly occurred. Zinc and sodium ions did not increase in the cytosol of AR42J cells even if 600 μM of zinc was added. However, calcium ion immediately increased in the cytosol after the addition of zinc and decreased quickly. Then, cytosol calcium content gradually increased again in a time-dependent manner. When 1.5 mM of calcium was added to the medium, the effect of 600 μM of zinc disappeared. On the contrary, rat pancreatic insulinoma cell line, RIN cells, did not increase cytosolic calcium concentration from zinc and necrosis was not induced by zinc. It is thought that zinc induces necrosis on AR42J cells by the increase of cytosolic calcium concentration, and the increase of extracellular calcium content inhibits the action of zinc that stimulates calcium transportation.
[en] The device's construction designed for sodium zirconate manufacturing has been described. The facility consists of the gas furnace with melting basin. The raw material after finishing the melting process is removed from the furnace by the specially constructed conveyor and cooled in the two rotating drums localized below the bleeder hole of the melting furnace. 2 figs
[en] A re-investigation of the lifetimes of seven 3p levels, seven 3d levels and one 4 s level of Na II has yielded results in fair agreement with earlier results from Lyon, and in excellent agreement with several calculations. The effect of incorporating data for the cascades in the analysis is demonstrated. (orig.)