An altered form of the cellular prion protein, the PrPScor PrPRes, is implicated in the occurrence of the still untreatable transmissible spongiform encephalopathies. We have previously synthesized and characterized aromatic compounds that inhibit protease-resistant prion protein (PrPRes) accumulation in scrapie-infected cells. These compounds belong to different chemical classes, including acy...

In the presence of alkali metal cations, guanosine-5'-hydrazide (1) forms stable supramolecular hydrogels by selective self-assembly into a G-quartet structure. Besides being physically trapped inside the gel structure, biologically active aldehydes or ketones can also reversibly react with the free hydrazide functions at the periphery of the G-quartet to form acylhydrazones. This particularity...

The preparation of two types of imidazole derivatives bearing a hydrazide group was achieved by treatment of the corresponding esters with NH2NH2·H2O in MeOH at room temperature. In the case of 4-(ethoxycarbonyl)-1H-imidazole 3-oxides 3, hydrazides of type 1 were formed with retention of the N-oxide structure (Scheme 1). Interestingly, due to a strong H-bonding, no deoxygenation of the N-O func...

 Let $R$ be a ring‎, ‎and let $n‎, ‎d$ be non-negative integers‎. ‎A right $R$-module $M$ is called $(n‎, ‎d)$-projective if $Ext^{d+1}_R(M‎, ‎A)=0$ for every $n$-copresented right $R$-module $A$‎. ‎$R$ is called right $n$-cocoherent if every $n$-copresented right $R$-module is $(n+1)$-coprese-nted‎, ‎it is called a right co-$(n,d)$-ring if every right $R$-module is $(n‎, ‎d)$-projective‎. ‎$R$...

MNDO semi-empirical SCF MO calculations are used to study the pyramidal nitrogen atom inversion and configurational equilibria in the title compounds.

let $r$ be a ring‎, ‎and let $n‎, ‎d$ be non-negative integers‎. ‎a right $r$-module $m$ is called $(n‎, ‎d)$-projective if $ext^{d+1}_r(m‎, ‎a)=0$ for every $n$-copresented right $r$-module $a$‎. ‎$r$ is called right $n$-cocoherent if every $n$-copresented right $r$-module is $(n+1)$-coprese-nted‎, ‎it is called a right co-$(n,d)$-ring if every right $r$-module is $(n‎, ‎d)$-projective‎. ‎$r$ ...

mndo semi-empirical scf mo calculations are used to study the pyramidal nitrogen atom inversion and configurational equilibria in the title compounds.

In this article we introduce the notion of n-capable groups. It is shown that every group G admits a uniquely determined subgroup (〖Z^n)〗^* (G) which is a characteristic subgroup and lies in the n-centre subgroup of the group G. This is the smallest subgroup of G whose factor group is n-capable. Moreover, some properties of n-central extension will be studied.

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Let $nin mathbb{N}$. An additive map $h:Ato B$ between algebras $A$ and $B$ is called $n$-Jordan homomorphism if $h(a^n)=(h(a))^n$ for all $ain A$. We show that every $n$-Jordan homomorphism between commutative Banach algebras is a $n$-ring homomorphism when $n < 8$. For these cases, every involutive $n$-Jordan homomorphism between commutative C-algebras is norm continuous.