Synthesis of Fmoc-protected N(δ)-acetyl-N(δ)-(tert-butoxy)-l-ornithine has revealed it to be a metal-chelating amino-acid precursor. This protected amino acid was compatible with the preparation of ferrichrome peptides by standard Fmoc-based solid-phase peptide synthesis. Evaluation of deferriferrichrysin for metal ion chelation revealed that zirconium(IV) and titanium(IV) formed complexes with...

In the last years, fixed point theorems have been applied to show the existence and uniqueness of the solutions of differential equations, integral equations and many other branches mathematics see, e.g., 1–3 . Some common fixed point theorems for weakly commuting, compatible, δ-compatible and weakly compatible mappings under different contractive conditions in metric spaces have appeared in 4–...

!! Ui // X The modules Mi are “restrictions“ or pullbacks of M along Ui → X, and are compatible in that if Mi,j is the pullback of Mi over Ui along Ui ×X Uj → Ui, then we have isomorphisms Mi,j ∼= Mj,i that satisfy a coherence condition known as the cocycle condition. We say that modules over affine schemes have the property of descent for a family {Ui → X} if any family of compatible modules M...

It is proven that a ring R is δ-semiperfect if and only if every right R-module is (amply) cofinitely δ-supplemented. Mathematics Subject Classification: 16L30, 16E50

We place ourselves in a so-called meet-closed description context; that is a context consisting of a finite nonempty entity set E whose elements are described in a complete meet-semilattice D, by means of a descriptor δ. Then we consider multiway quasi-ultrametric dissimilarities on E, a class of multiway dissimilarities that, with their relative k-balls, extend the fundamental in classificatio...

Let A be a hereditary algebra over an algebraically closed field k andA(m) be them-replicated algebra of A. Given an A(m)-module T , we denote by δ(T ) the number of non isomorphic indecomposable summands of T . In this paper, we prove that a partial tilting A(m)module T is a tilting A(m)-module if and only if δ(T ) = δ(A(m)), and that every partial tilting A(m)-module has complements. As an ap...

let $r$ be an arbitrary ring with identity and $m$ a right $r$-module with $s=$ end$_r(m)$. the module $m$ is called {it rickart} if for any $fin s$, $r_m(f)=se$ for some $e^2=ein s$. we prove that some results of principally projective rings and baer modules can be extended to rickart modules for this general settings.

For a ring endomorphism α and an α-derivation δ, we introduce α-compatible ideals which are a generalization of α-rigid ideals and study the connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x;α, δ] and the skew power series R[[x;α]]. As a consequence we obtain a generalization of Hong, Kwak and Rizvi, 2005.