to calculation non-bonded interaction of the [cocl6]3- complex embedded in nano ring, we focus on the single wall boron-nitride b18n18 nano ring. thus, the geometry of b18n18 nano ring has been optimized by b3lyp method with epr-ii (electron paramagnetic resonance) basis set and geometry of the [cocl6]3- complex has been optimized at b3lyp method with aldrich’s vtz basis set and stuttgart rsc 1...

how to cite this article: shetty g, avabratha k.s, rai b.s. ring-enhancing lesions in the brain: a diagnostic dilemma. iran j child neurol. 2014 summer;8(3): 61-64. abstract the most common radiological abnormality seen in young indian patients with epilepsy is single small enhancing (ring/disc) computed tomographic (ct) lesions. the two most common differential diagnosis of this lesion in clin...

In the title mol-ecule, C(34)H(53)BrO(4), all the cyclo-hexane rings adopt chair conformations, while the cyclo-pentane ring adopts an envelope conformation. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into corrugated sheets parallel to the ab plane.

In the title compound, C(25)H(30)O, the adamantane cage consists of three fused cyclo-hexane rings in classical chair conformations, with C-C-C angles in the range 107.15 (9)-111.55 (9)°. The dihedral angle between the benzene rings is 46.91 (4)° and the conformation is stabilized by a weak intra-molecular C-H⋯π inter-action.

In the title compound, C(26)H(32)N(2), the cyclo-hexane and piperazine rings each adopt a chair conformation. Both phenyl rings and the two propen-3-yl residues are in equatorial positions. There are no C-H⋯N hydrogen bonds nor π-π inter-actions between the aromatic rings. The absolute configuration was assigned with reference to the starting material.

In the title compound, C(21)H(24)N(2)O(4), the piperidine ring adopts a distorted boat conformation. The crystal structure is stabilized by C-H⋯π inter-actions involving one of the methoxy-phenyl rings.

In the title compound, C18H22O4, the cyclo-hexane and cyclo-hexa-none rings adopt normal chair and half-chair conformations, respectively. The dioxolane ring is almost planar, with an r.m.s. deviation of 0.094 (3) Å. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds, forming 21 helical chains along the a-axis direction. The chains are further connected by C-H⋯O hydrogen bonds.

Let R be a commutative ring with identity and M be a unitary R-module. Let : S(M) −! S(M) [ {;} be a function, where S(M) is the set of submodules ofM. Suppose n 2 is a positive integer. A proper submodule P of M is called(n − 1, n) − -prime, if whenever a1, . . . , an−1 2 R and x 2 M and a1 . . . an−1x 2P(P), then there exists i 2 {1, . . . , n − 1} such that a1 . . . ai−1ai+1 . . . an−1x 2 P...

let $r$ be an associative ring with identity. an element $x in r$ is called $mathbb{z}g$-regular (resp. strongly $mathbb{z}g$-regular) if there exist $g in g$, $n in mathbb{z}$ and $r in r$ such that $x^{ng}=x^{ng}rx^{ng}$ (resp. $x^{ng}=x^{(n+1)g}$). a ring $r$ is called $mathbb{z}g$-regular (resp. strongly $mathbb{z}g$-regular) if every element of $r$ is $mathbb{z}g$-regular (resp. strongly $...