Reversible C-C bond formation in group 4 metal complexes: nitrile extrusion β-aryl elimination.

Pyridylamides of zirconium and hafnium with [C,N,N]-ligands reversibly insert nitriles into M-C bonds leading to an observable equilibrium between the starting [C,N,N]-complexes and newly formed [N,N,N]-complexes with a ketimide moiety in a 7-membered metallacycle. The discovered reversible insertion of nitriles into M-C bonds represents an unprecedented example of β-aryl elimination from a ketimide ligand in early transition metal complexes. Experimental and computational studies suggest thermodynamic and electronic reasons for this reactivity.

[The hyperiricosuria as an indicator of derangement of biologic functions of endoecology and adaptation, biologic reactions of excretion, inflammation and arterial tension].

During millions years in all animals allantoine (oxidized by uricase uric acid) was catabolite of purines and ascorbic acid was an acceptor of active forms of oxygen. The proximal tubules of nephron reabsorbed the trace amounts of uric acid Then during phylogenesis the primates had a mutation of ascorbic acid gen minus. Later on occurred a second spontaneous mutation and uricase gen minus and uric acid became catabolites of purines.

[Basic principles of creation of multilevel multistage mathematical model of aging].

Current knowledge on the aging allows to elaborate approaches to the creation of multilevel model of multistage of human aging taking into consideration events during the aging at various levels of integration: molecular, cellular, tissue, organ, systemic, organism. The present paper have deals with main states of the mathematical model of multistage aging, principles of its construction, applicability and evaluation of its prognostic power. There are 3 levels of integrative systems: homeostatic (organismal), systemic and cellular-molecular.

[Investigation of disability prevalence in men and women of advanced age].

Disability prevalence among men and women are investigated using NLTCS surveys conducted in 1982, 1984, 1989, 1994 and 1999 in the US population, on persons older than 65 years, and data from LSADT surveys conducted in 1995, 1997, 1999 and 2001 in the population of the Danish Twins Registry, on persons older than 75 years. In both surveys women are more disabled than men. The probability of becoming disabled and surviving is higher for women than men.