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[en] Highlights: • Successfully intercalation of dual-surfactants into montmorillonite. • Preparation of phosphonium-ammonium-modified montmorillonites. • Hybrid-organic-montmorillonite (HOMt) with intermediate properties. • Statistical approach to optimize the hybrid montmorillonite properties.
[en] Tilting of a deployed filter in the inferior vena cava (IVC) is a particular kind of periprocedural complication and this can reduce the filter's clot-trapping ability and increase the occlusion of the IVC at a later period. The authors report here on a case of spontaneous tilting of an inferior vena caval filter that was associated with thrombosis in the IVC within 2 weeks of the initially successful placement of the filter without tilting
[en] The supramolecule, p-t-Butyl calix(8)arene, forms inclusion complex with the antiseizure drug molecule, ethosuximide. This feature is explained on the basis of optical absorption spectroscopy. Here p-t-Butyl calix(8)arene is the host molecule and ethosuximide is the guest molecule. The stoichiometry of the host–guest complex and the binding constant has been determined using Benesi–Hildebrand plot. Based on the result obtained the structure of the inclusion complex has been proposed. -- Highlights: ► Third generation supramolecule, t-butyl calix (8) arene, is used as a host molecule. ► Anti seizure drug molecule is used as a guest molecule. ► Inclusion complex is formed between the host and guest molecule
[en] Various equilibrium and nonequilibrium aspects of staging and stage transformations in graphite intercalation compounds are investigated. A simple thermodynamic model of intercalated graphite that allows for variation of in-plane intercalant density and takes explicit account of volume variation is presented. Assuming random occupation of intercalant atoms, pressure-temperature-concentration phase diagrams are calculated. The model is capable of explaining pressure-induced staging transformation, the appearance of fractional stage at high pressure, and other experimentally observed effects in alkali metal-graphite compounds. In order to address the mechanism of stage transformations a set of diffusion equations based on time-dependent Landau-Ginzburg theory is derived. As illustrations of the formalism, stage decomposition in a quenched sample and the intercalation of a dilute sample are studied. Staggered domains of intermediate stages are shown to arise naturally as a consequence of the interactions and the kinetic constraints. Further, it is shown that intercalation proceeds through the formation and migration of islands of intermediate stages. All the results are in qualitative agreement with experiments
[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] This article describes the preparation of a series of inclusion complexes of anhydrolycorine with three cyclodextrins (CDs), namely β-CD, γ-CD, and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), and their successful characterization through UV, TG, DSC, XRD, SEM, 1H NMR, and 2D NMR spectroscopies. The results demonstrated that the water solubility of anhydrolycorine increased notably by about 23-42 times after the inclusion complexation with these CDs. Furthermore, preliminary in vitro cytotoxicity experiments on human colon cancer cell lines HT-29, SW480, HCT116, and DLD-1 were also performed, and the complexes showed remarkable anticancer activity against HT-29, SW480, and HCT116. These results suggested that the inclusion complexes would be potentially useful for applications for human colon cancer chemotherapy. (author)
[en] Real graphene sheets show limited anti-permeation performance deviating from the ideally flat honeycomb carbon lattice that is impermeable to gases. Ripples in graphene are prevalent and they could significantly influence carrier transport. However, little attention has been paid to the role of ripples in the permeation properties of graphene. Here, we report that gases can permeate through graphene ripples at room temperature. The feasibility of gas permeation through graphene ripples is determined by detecting the initial oxidation sites of Cu surface covered with isolated graphene domain. Nudged elastic band (NEB) calculations demonstrate that the oxygen atom permeation occurs via the formation of C–O–C bond, in which process the energy barrier through the rippled graphene lattice is much smaller than that through a flat graphene lattice, rendering permeation through ripples more favorable. Combining with the recent advances in atoms intercalation between graphene and metal substrate for transfer-free and electrically insulated graphene, this discovery provides new perspectives regarding graphene’s limited anti-permeation performance and evokes for rational design of graphene-based encapsulation for barrier and selective gas separation applications through ripple engineering. (paper)