Categories of models of R-mingle

We give a new Esakia-style duality for the category of Sugihara monoids based on the Davey-Werner natural duality for lattices with involution, and use this duality to greatly simplify a construction due to Galatos-Raftery of Sugihara monoids from certain enrichments of their negative cones. Our method of obtaining this simplification is to transport the functors of the Galatos-Raftery construction across our duality, obtaining a vastly more transparent presentation on duals. Because our duality extends Dunn's relational semantics for the logic R-mingle to a categorical equivalence, this also explains the Dunn semantics and its relationship with the more usual Routley-Meyer semantics for relevant logics.     

An Improved Method for Site‐Specific End Modification of Zeolite L for the Formation of Zeolite L and Gold Nanoparticle Self‐Assembled Structures

The ability to site‐selectively modify micro‐ and nanosized particles has allowed for directed self‐assembly in two and three dimensions. Site‐selective modification of particles can be a complicated task requiring the pre‐organization of particles or enhanced particle fabrication methods. The aluminum silicate, zeolite L has been reported to undergo site‐specific modification at the zeolite channel entrances, post‐fabrication in a solution‐based method. The process by which the channel entrances are site selectively modified is explored here. The preliminary step of charging the zeolite channels with aqueous acid allows for catalysis of covalent bond formation at the channel entrances. Three new end‐specific modification reagents are described based on silanol and silyl ether functional groups. These reagents are purified by column chromatography and characterized by¹H NMR spectroscopy and high resolution mass spectrometry (HRMS); they provide for reliable end modification of zeolites L. Preferential reactivity at the channel entrances is also observed. The utility of the approach is demonstrated by modifying zeolite L with adamantane at the channel entrances. Site‐specific self‐assembly with β‐cyclodextrin coated gold nanoparticles can be triggered with a chemical stimulus. The resulting multivalent host‐guest interactions give gold clustered nanoparticles at the ends of the micrometer‐sized zeolites.     

POCl3-mediated synthesis of hydrolysis-prone 2-trifluoroethylbenzimidazoles

Loss of a trifluoromethyl group has been observed as an unproductive side reaction in the formation of 2-trifluoroethylbenzimidazoles. A hydrolytic mechanism for this transformation is proposed that is consistent with evidence for the identity of reaction intermediates. Cyclodehydration with POCl₃ suppresses hydrolysis of the trifluoromethyl group and provides 2-trifluoroethylbenzimidazoles in good yields.     

The thermolysis of the neocupferron chelates of yttrium and the rare earth elements

The thermolosis curves of the neocupferron chelates of yttnum, lanthanum, cerium(III), cerium(IV). praseodymium, neodymium, samarium and gadolinuim were determined. It was found that the ehelates were stable up to 8o°, with the oxide levels being reached at 460–750°.     

MR of an adrenal pseudocyst

We describe the appearance of an adrenal pseudocyst on MRI and CT. The MR characteristics of the lesion were noteworthy in that the lesion had two components with different imaging characteristics. The larger component was of low signal intensity on both T₁- and T₂-weighted images and might have been confused with an adrenal adenoma.     

Synthesis of 1,5-dideazariboflavin

1,5-Dideazariboflavin, an analog of riboflavin containing the original conjugated double bond system between positions 1 and 5, was synthesized by the condensation of 4,5-dimethyl- N-ribitylanthranilaldehyde and the sodium salt of 2,4,6-piperidinetrione.     

The thermal decomposition of the 5,7-dihalo-8-quinolinol rare earth metal chelates

The thermal decomposition of the 5,7-dichloro-, 5,7-dibromo- and 5,7-duodo-8-quinohnol chelates of lanthanum, cerium, praseodymium, neodymium, samarium and yttrium was investigated on the thermobalance. The chelates decomposed in the temperature range from 65 to 125°C while the oxide levels were obtained from 395 to 805°C Although the chelate thermal stability temperatures varied little with the chelating agent, the minimum oxide level temperatures were largely dependent on the halogen substitution on the 8-quinolinol molecule. Results of this study were correlated with previous studies on the rare earth metal chclatcs with 8-quinolinol and 2-methyl-8-quinolinol.