Equatorial/axial conversion in piperidine and phosphorinane with different substituents wereinvestigated with great details. Three possible routes, i.e. heteroatom inversion and two ring inversiontype were considered. Ring conversion can occur via two pathways one starts with ring flatteningfrom the heteroatom site (nitrogen in piperidine and phosphorous in phosphorinane) and the otherinitiates...

background digital nerve block is commonly performed by care providers in medical fields. this study compares the blocks in terms of effectiveness of anesthesia and pain. methods patients were divided into two groups. first group underwent digital block whereas 2nd group had transmetacarpal digital block. the subcutaneous ring block was performed by two injections of 3 ml of 2% lignocaine in a ...

in this paper we study triangularization of collections of matrices whose entries come from a finite-dimensional division ring. first, we give a generalization of guralnick's theorem to the case of finite-dimensional division rings and then we show that in this case the reduced trace function is a suitable alternative for trace function by presenting two triangularization results. the firs...

the anticoagulant racemic warfarin is synthesized by the michael addition of 4-hydroxycoumarin with benzalacetone in the present of equimolar amounts of imidazolium based ionic liquids [bmim] bf4 and [bmim] br and other reaction solvents such as h2o, pyridine and ammonia in five different tests. also synthesis of a derivative of warfarin (2-methyl-4-phenyl pyrano [3, 2-c] chromen-5(4h)-one) und...

a mild, green and highly efficient route for regio-selective amination of oxiranes was developed via incorporation of mn(ii), fe(ii), co(ii), ni(ii), cu(ii) and zn(ii) cations onto the surface of hydroxyapatite-encapsulated γ-fe2o3 nanoparticles (γ-fe2o3@hap). among six magnetically recoverable catalytic systems denoted as [γ-fe2o3@hap-mii], the catalyst in which m designated as fe(ii) showed t...

polydimethylsiloxane (pdms) has been synthesized by ring-opening polymerization of octamethylcyclotetrasiloxane (d4) in microemulsion with acidic catalyst. the structure and properties of microemulsion were characterized by transmission electron microscopy (tem), fourier transform infrared spectroscopy (ft-ir), photo correlation spectroscopy (pcs). the effect of the variation in ph value, amoun...

It is shown that a commutative reduced ring R is a Baer ring if and only if it is a CS-ring; if and only if every dense subset of Spec (R) containing Max (R) is an extremally disconnected space; if and only if every non-zero ideal of R is essential in a principal ideal generated by an idempotent.

we introduce the class of “right almost v-rings” which is properly between the classes of right v-rings and right good rings. a ring r is called a right almost v-ring if every simple r-module is almost injective. it is proved that r is a right almost v-ring if and only if for every r-module m, any complement of every simple submodule of m is a direct summand. moreover, r is a right almost v-rin...

autism is a complex neuropsychiatric disorder that manifests in early childhood. although the etiology is unknown yet but, new hypothesis focused on identifying the key genes related to autism may elucidate its etiology. the main objective of the present study was to verify the value of karyotyping in autistic children and identifying association between chromosome abnormalities and autism.we e...