Let R be a finite commutative ring. We prove that a MacWilliams type relation between the m-spotty weight enumerators of a linear code over R and its dual hold, if and only if, R is a Frobenius (equivalently, Quasi-Frobenius) ring, if and only if, the number of maximal ideals and minimal ideals of R are the same, if and only if, for every linear code C over R, the dual of the dual C is C itself...

The C-branched sugar d-apiose (Api) is essential for plant cell-wall development. An enzyme-catalyzed decarboxylation/pyranoside ring-contraction reaction leads from UDP-α-d-glucuronic acid (UDP-GlcA) to the Api precursor UDP-α-d-apiose (UDP-Api). We examined the mechanism of UDP-Api/UDP-α-d-xylose synthase (UAXS) with site-selectively 2 H-labeled and deoxygenated substrates. The analogue UDP-2...

nitro-containing heteroaromatic derivatives structurally related to nitroimidazole (metronidazole) are being extensively evaluated against helicobacter pylori isolates. on the other hand, 1,3,4-thiadiazole derivatives have also demonstrated promising antibacterial potential. in present study, we evaluated anti-h. pylori activity of novel hybrid molecules bearing nitroaryl and 1,3,4-thiadiazole ...

Reaction of a nucleobase with nitrosonium ion leads to its diazotization. Due to the instability,the nucleobase-diazonium assumingly falls in dediazotization and successive ring openingreactions. The resulting intermediate of the ring opening reaction is able to covalently cross-linkthe opposite strands of DNA. To examine this assumption for cytosine, some 4-amino-5-cyanopyrimidines were synthe...

A contact mapping strategy was applied to identify putative amino acid residues that influence the oxidosqualene-lanosterol B-ring cyclization reaction. A bicyclic intermediate with two altered deprotonation products, in conjunction with lanosterol, were isolated from the ERG7(Y707X) mutants, indicating that the Tyr707 residue may play a functional role in stabilizing the chair-boat bicyclic C-...

(S)-2-Hydroxypropylphosphonic acid [(S)-HPP] epoxidase (HppE) is a mononuclear iron enzyme that catalyzes the last step in the biosynthesis of the antibiotic fosfomycin. HppE also processes the (R)-enantiomer of HPP but converts it to 2-oxo-propylphosphonic acid. In this study, all four stereoisomers of 3-methylenecyclopropyl-containing substrate analogues, (2R, 3R)-8, (2R, 3S)-8, (2S, 3R)-8, a...

in this article, we study the artin-rees property in  c(x), in the  rings of fractions of  c(x) and in the factor rings of c(x) . we show that c(x)/(f) is an artin-rees ring if and only if  z(f)  is an open p-space. a necessary and sufficient condition for the local rings of  c(x)   to be artin-rees rings is that each prime ideal in  c(x)  becomes minimal and it turns out that every local ring ...

the mean fiber length of three beech trees (fagus orientalis l.) at the lower and higher points (1% and 75% tree height) of the stem at an intermediate altitude (500-1000m) in the caspian forests in sari region were 1.36 and 1.22mm respectively, close to the values in three trees at high altitude (1000-1500m), that were found to be 1.39 and 1.36 mm. the mean fiber lengths of the whole stem, usi...

In the 1- (4-fluorophenyl) -2,3-dihydro-1 H-naphto- [1 and 2-e] [1 and 3] oxazine-3-n, there are 4 rings, respectively, rings from the side attached to the halogen They are named C, B, A, and D. Calculations and studies show that the amount of aromatics in the halogen-ring A in all cases has the highest number. In the B loop, the predicted aromatism level is zero, and in the ring C and D, relat...

Let $(R,fm,k)$ be a local Gorenstein ring of dimension $n$. Let $H_{I,J}^i(R)$ be the  local cohomology with respect to a pair of ideals $I,J$ and $c$ be the $inf{i|H_{I,J}^i(R)neq0}$. A pair of ideals $I, J$ is called cohomologically complete intersection if $H_{I,J}^i(R)=0$ for all $ineq c$. It is shown that, when $H_{I,J}^i(R)=0$ for all $ineq c$, (i) a minimal injective resolution of $H_{I,...