the aim of this paper is to generalize the‎‎notion of pseudo-almost valuation domains to arbitrary‎ ‎commutative rings‎. ‎it is shown that the classes of chained rings‎ ‎and pseudo-valuation rings are properly contained in the class of‎ ‎pseudo-almost valuation rings; also the class of pseudo-almost‎ ‎valuation rings is properly contained in the class of quasi-local‎ ‎rings with linearly ordere...

For a ring endomorphism $alpha$ and an $alpha$-derivation $delta$, we introduce a concept, so called skew $pi$-Armendariz ring, that is a generalization of both $pi$-Armendariz rings, and $(alpha,delta)$-compatible skew Armendariz rings. We first observe the basic properties of skew $pi$-Armendariz rings, and extend the class of skew $pi$-Armendariz rings through various ring extensions. We nex...

statement of the problem: implant-retained overdenture can improve the stability of dentures and prevent bone loss. overdenture-wearing patients need special hygiene care. purpose: the aim of this study was to evaluate the effects of various denture cleansers on the retention of dio orange o-rings. method and materials : in this experimental study, 40 dio orange o-rings were divided into 4 grou...

Nature has exploited medium-sized 8- to 11-membered rings in a variety of natural products to address diverse and challenging biological targets. However, owing to the limitations of conventional cyclization-based approaches to medium-ring synthesis, these structures remain severely underrepresented in current probe and drug discovery efforts. To address this problem, we have established an alt...

The results of MNDO, AM1 and PM3 semi-empirical calculations and HF/6-31G*, MP/6-31G*, MP2/6-311+G**, and B3LYP/6-311G** and QCISD/6-31G* ab initio methods for angle strain and conjugation effects in twist-boat, boat, and half-chair geometries of (Z,Z,Z)-cycloocta-1,3,5-triene indicate that all methods, except PM3, predict wrong ordering of the conformations.

The aim of this paper is to generalize the‎‎notion of pseudo-almost valuation domains to arbitrary‎ ‎commutative rings‎. ‎It is shown that the classes of chained rings‎ ‎and pseudo-valuation rings are properly contained in the class of‎ ‎pseudo-almost valuation rings; also the class of pseudo-almost‎ ‎valuation rings is properly contained in the class of quasi-local‎ ‎rings with linearly ordere...

Streptomyces coelicolor A3(2) ftsI- and ftsW-null mutants produced aerial hyphae with no evidence of septation when grown on a traditional osmotically enhanced medium. This phenotype was partially suppressed when cultures were grown on media prepared without sucrose. We infer that functional FtsZ rings can form in ftsI- and ftsW-null mutants under certain growth conditions.

The creation of carbon-carbon and carbon-heteroatom bonds by the oxidation of organocuprates is useful in a range of challenging contexts including the formation of biaryl bonds within medium rings, diene synthesis and the coupling of tertiary carbon centres. This tutorial review introduces these applications and recent developments which have served to improve its functional group tolerance an...

Recent ALMA observations have revealed that a large fraction of protoplanetary discs contain bright rings at (sub)millimeter wavelengths. Dust trapping induced by pressure maxima in the gas disc is popular explanation for these rings. However, it unclear whether such bumps can survive evolutionary time-scales disc. In this work, we investigate an alternative scenario, which involves only dust-g...