Xanthine phosphoribosyltransferase (XPRT) and hypoxanthine-guanine (HGPRT) are purine salvaging enzymes of Leishmania donovani with distinct 6-oxopurine specificities. LdXPRT phosphoribosylates xanthine, hypoxanthine, guanine, preference toward whereas LdHGPRT only hypoxanthine guanine. In our study, was used as a model to understand these base Mutating I209 V, the conserved residue found in HG...

Iterated Hopf Ore extensions (IHOEs) over an algebraically closed base field $\Bbbk$ of positive characteristic $p$ are studied. We show that every IHOE satisfies a polynomial identity (PI), with PI-degree power $p$, and it is filtered deformation commutative ring. classify all $2$-step IHOEs $\Bbbk$, thus generalising the classification $2$-dimensional connected unipotent algebraic groups $\Bb...

Given distinct points p1, . . . , pr of a smooth variety V (over an algebraically closed field k) and positive integers mi, Z = m1p1 + · · · +mrpr denotes the subscheme defined locally at each point pi by I mi i , where Ii is the maximal ideal in the local ring OV,pi at pi of the structure sheaf. More briefly, we say Z is a fat point subscheme of V . In the case that V is P for some n, it is of...

Throughout this paper all rings are commutative, with identity, and Noetherian, unless otherwise specified. In particular, “local ring” always means Noetherian local ring, unless otherwise specified. Our objective is to prove a generalization of Faltings’ connectedness theorem [Fal1, Fal2], which asserts that in a complete local domain (R,m,K) of dimension n, if I ⊆ m is an ideal generated by a...

in this paper, we study some ring theoretic properties of the amalgamated duplication ring $rbowtie i$ of a commutative noetherian ring $r$ along an ideal $i$ of $r$ which was introduced by d'anna and fontana. indeed, it is determined that when $rbowtie i$ satisfies serre's conditions $(r_n)$ and $(s_n)$, and when is a normal ring, a generalized cohen-macaulay ring and finally a filter ring.

A $\ast$-ring
 $R$ is called a $\pi$-Baer $\ast$-ring, if for any projection invariant left ideal $Y$ of $R$, the right annihilator $Y $
 generated, as ideal, by projection.
 In this note, we
 study some properties such $\ast$-rings.
 We indicate interrelationships between $\ast$-rings and related classes rings as
 rings, Baer $\ast$-rings, quasi-Baer $\ast$-rings....

The alkali metal cations Na(+) and K(+) have several important physiological roles, including modulating enzyme activity. Recent work has suggested that alkali metal cations may be coordinated by pi systems, such as the aromatic amino acid side chains. The ability of K(+) to interact with an aromatic ring has been assessed by preparing a family of synthetic receptors that incorporate the aromat...

The electronic environment of nitrogen in nucleic acid bases, nucleotides, polynucleotides and DNA has been studied, for the first time using X-Ray Absorption Near-Edge Spectroscopy (XANES). Generally, the spectra of these complex molecules consist of low energy bands corresponding to 1s-->pi* transitions and high energy bands corresponding to 1s-->sigma* transition, as illustrated using severa...

in this paper, we introduce a class of $j$-quasipolar rings. let $r$ be a ring with identity. an element $a$ of a ring $r$ is called {it weakly $j$-quasipolar} if there exists $p^2 = pin comm^2(a)$ such that $a + p$ or $a-p$ are contained in $j(r)$ and the ring $r$ is called {it weakly $j$-quasipolar} if every element of $r$ is weakly $j$-quasipolar. we give many characterizations and investiga...

We report the experimental observation of stable pulse pairs with a +/-pi/2 phase difference in a passively mode-locked stretched-pulse fiber ring laser. In our setup the stabilization of interacting subpicosecond pulses is obtained with a large range of pulse separations, namely, from 2.7 to 10 ps, without the need for external control.