Résumé. Étant donné un anneau de valuation $V$ , corps résiduel $F$ et groupe des valeurs $\Gamma$, on donne une condition suffisante pour qu’un local dominant soit $\Gamma$. Lorsque contient $k$, ce résultat est appliqué à la construction d’un contenant extension donnée $k'$ $\Gamma$ engendré par $F$. Cela s’avère possible, notamment, lorsque ou séparable sur $k$. Abstract. Given a ring $V$, w...

The structure of a new anthra-gamma-pyrone antitumor antibiotic sapurimycin was determined by the spectral studies of its methyl ester. Sapurimycin has the same anthra-gamma-pyrone skeleton as pluramycin, but is distinctly different because of the absence of sugars on the D ring and possessing a carboxylmethyl group on C-5.

gamma-Tubulin is critical for the initiation and regulation of microtubule (MT) assembly. In Drosophila melanogaster, it acts within two main complexes: the gamma-tubulin small complex (gamma-TuSC) and the gamma-tubulin ring complex (gamma-TuRC). Proteins specific of the gamma-TuRC, although nonessential for viability, are required for efficient mitotic progression. Until now, their role during...

Previous studies indicate that gamma tubulin ring complex (gammaTuRC) can nucleate microtubule assembly and may be important in centrosome formation. gammaTuRC contains approximately eight subunits, which we refer to as Xenopus gamma ring proteins (Xgrips), in addition to gamma tubulin. We found that one gammaTuRC subunit, Xgrip109, is a highly conserved protein, with homologues present in yeas...

BACKGROUND Three-ring polyamides containing N-methylimidazole and N-methylpyrrole amino acids bind sequence-specifically to double-helical DNA by forming side-by-side complexes in the minor groove. Simple pairing rules relate the amino-acid sequence of a pyrrole-imidazole polyamide to its expected DNA target site, and polyamides that target a wide variety of DNA sequences have been synthesized....

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.

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...