tacrine (9-amino-1,2,3,4-tetrahydroacridine) as a reversible inhibitor of acetylcholinesterase (ache),was the first drug for the symptomatic treatment of alzheimer’s disease (ad). nmr structuredetermination still presents some considerable challenges: the method is limited to systems ofrelatively small molecular mass, data collection times are long, data analysis remains a lengthyprocedure, and...

with the aim of recognizing the steric effects on the silylenic r2c6h6si structures, dft calculationsare carried out on 8 structures of r2c6h6si (where r is hydrogen (h), methyl (me), isopropyl (i-pro),and tert-butyl (tert-bu)). these species are at either triplet (t) or singlet (s) states. singlet–tripletenergy separations ( me (20.32) > t-bu (15.92).all singlet states of r2c6h6si, are more st...

‎We firstly prove the completeness of the category of crossed modules in a modified category of interest‎. ‎Afterwards‎, ‎we define pullback crossed modules and pullback cat objects that are both obtained by pullback diagrams with extra structures on certain arrows‎. ‎These constructions unify many corresponding results for the cases of groups‎, ‎commutative algebras and can also be adapted to ...

In addition to exploring constructions and properties of limits and colimits in categories of topological algebras, we study special subcategories of topological algebras and their properties. In particular, under certain conditions, reflective subcategories when paired with topological structures give rise to reflective subcategories and epireflective subcategories give rise to epireflective s...