scholarly journals New route toward nanosized crystalline metal borides with tuneable stoichiometry and variable morphologies

2016 ◽  
Vol 191 ◽  
pp. 511-525 ◽  
Author(s):  
Guillaume Gouget ◽  
Patricia Beaunier ◽  
David Portehault ◽  
Clément Sanchez

Herein we highlight for the first time the ability to tune the stoichiometry of metal boride nanocrystals through nanoparticle synthesis in thermally stable inorganic molten salts. Two metal–boron systems are chosen as case studies: boron-poor nickel borides and boron-rich yttrium borides. We show that NiB, Ni4B3, Ni2B, Ni3B, and YB6 particles can be obtained as crystalline phases with good selectivity. Anisotropic crystallization is observed in two cases: the first boron-rich YB4 nanorods are reported, while boron-poor NiB nanoparticles show a peculiar crystal habit, as they are obtained as spheres with uniaxial defects related to the crystal structure. Crystallization mechanisms are proposed to account for the appearance of these two kinds of anisotropy at the nanoscale.

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 298
Author(s):  
Yefen Zhu ◽  
Yanlei Kang ◽  
Ling Zhu ◽  
Kaxi Yu ◽  
Shuai Chen ◽  
...  

Canagliflozin (CG) was a highly effective, selective and reversible inhibitor of sodium-dependent glucose co-transporter 2 developed for the treatment of type 2 diabetes mellitus. The crystal structure of CG monohydrate (CG-H2O) was reported for the first time while CG hemihydrate (CG-Hemi) had been reported in our previous research. Solubility and dissolution rate results showed that the solubility of CG-Hemi was 1.4 times higher than that of CG-H2O in water and hydrochloric acid solution, and the dissolution rates of CG-Hemi were more than 3 folds than CG-H2O in both solutions. Hirshfeld surface analysis showed that CG-H2O had stronger intermolecular forces than CG-Hemi, and water molecules in CG-H2O participated three hydrogen bonds, forming hydrogen bond networks. These crystal structure features might make it more difficult for solvent molecules to dissolve CG-H2O than CG-Hemi. All these analyses might explain why the dissolution performance of CG-Hemi was better than CG-H2O. This work provided an approach to predict the dissolution performance of the drug based on its crystal structure.


2020 ◽  
Vol 251 ◽  
pp. 123101
Author(s):  
Wei Cai ◽  
Jiayao Deng ◽  
Huimin Lu ◽  
Yuan Cao

1998 ◽  
Vol 51 (1) ◽  
pp. 83-129 ◽  
Author(s):  
Annegret Fauser

In 1903, one hundred years after the Prix de Rome had been created in music composition, women were allowed to participate in the competition for the first time. In 1913, Lili Boulanger became the first woman to win the prize, crowning the efforts of three others-Juliette Toutain, Hélène Fleury, and Nadia Boulanger-to achieve this goal. Their stories are fascinating case studies of the strategies women employed to achieve success and public recognition within the complex framework of French cultural politics at the beginning of the twentieth century.


RSC Advances ◽  
2016 ◽  
Vol 6 (14) ◽  
pp. 11211-11217 ◽  
Author(s):  
Xue Chen ◽  
Qidi Wang ◽  
Fengzhu Lv ◽  
Paul K. Chu ◽  
Yihe Zhang

RbCaGd(PO4)2:Eu2+ was prepared by the Pechini-type sol–gel method. The crystal structure was determined in the first time. The dipole–dipole interaction plays a major role in the mechanism of concentration quenching of Eu2+ in this phosphor.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 946
Author(s):  
Tom E. Forshaw ◽  
Julie A. Reisz ◽  
Kimberly J. Nelson ◽  
Rajesh Gumpena ◽  
J. Reed Lawson ◽  
...  

Human peroxiredoxins (Prx) are a family of antioxidant enzymes involved in a myriad of cellular functions and diseases. During the reaction with peroxides (e.g., H2O2), the typical 2-Cys Prxs change oligomeric structure between higher order (do)decamers and disulfide-linked dimers, with the hyperoxidized inactive state (-SO2H) favoring the multimeric structure of the reduced enzyme. Here, we present a study on the structural requirements for the repair of hyperoxidized 2-Cys Prxs by human sulfiredoxin (Srx) and the relative efficacy of physiological reductants hydrogen sulfide (H2S) and glutathione (GSH) in this reaction. The crystal structure of the toroidal Prx1-Srx complex shows an extended active site interface. The loss of this interface within engineered Prx2 and Prx3 dimers yielded variants more resistant to hyperoxidation and repair by Srx. Finally, we reveal for the first time Prx isoform-dependent use of and potential cooperation between GSH and H2S in supporting Srx activity.


2018 ◽  
Vol 32 (5) ◽  
pp. 23-25 ◽  
Author(s):  
Lucie Cuvelier

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings An operative approach is described that is designed to structure the debriefing along three axes. Practical implications The paper provides strategic insights and practical thinking that have influenced some of the world’s leading organizations. Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.


2017 ◽  
Vol 73 (10) ◽  
pp. 1497-1500
Author(s):  
Khamid U. Khodjaniyazov ◽  
Utkir S. Makhmudov ◽  
Kambarali K. Turgunov ◽  
Burkhon Z. Elmuradov

Selective C-formylation of 8,9,10,11-tetrahydropyrido[2′,3′:4,5]pyrimido[1,2-a]-azepin-5(7H)-one has been studied for the first time. It was revealed that formylation proceeds by the formation of an intermediate salt, which due to the re-amination process on treatment with aqueous ammonia transformed into the corresponding (E)-11-(aminomethylene)-8,9,10,11-tetrahydropyrido[2′,3′:4,5]-pyrimido[1,2-a]azepin-5(7H)-one, C13H14N4O, as anE-isomer. Formylation was carried out by Vilsmeier–Haack reagent and the structure of the synthesized compound was confirmed by X-ray structural analysis, spectroscopic and LC–MS methods. In the molecule, the seven-membered pentamethylene ring adopts a twist-boat conformation.


1989 ◽  
Vol 31 (8) ◽  
pp. 411-419 ◽  
Author(s):  
H.M. Edwards ◽  
J.B. Thompson ◽  
P Smith
Keyword(s):  

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