Ataxia telangiectasia (AT) is a pleiotropic genetic disorder characterized by progressive neurodegeneration, especially of cerebellar Purkinje cells, immunodeficiency, increased incidence of cancer, and premature aging. The disease is caused by functional inactivation of the ATM (AT-mutated) gene product, which is thought to act as a sensor of reactive oxygen species and oxidative damage of cellular macromolecules and DNA. The compound phenotype of AT might thus be linked to a continuous state of oxidative stress leading to an increase of programmed cell death (apoptosis). To assess this hypothesis, we analyzed lipid peroxidation products and the oxidative stress associated DNA base damage 8-hydroxy-2-deoxyguanosine in patients with AT. Oxidative damage to lipids and DNA was found to be markedly increased in AT patients. These results indicate that ATM might play an important role in the maintenance of cell homeostasis in response to oxidative damage. In this context, a better control of levels of reactive oxygen species could be a rational foundation of therapeutic intervention to help alleviate some of the symptoms associated with AT.
A new Ru oligomer
of formula {[Ru
II
(bda-κ-N
2
O
2
)(4,4′-bpy)]
10
(4,4′-bpy)},
10
(bda is [2,2′-bipyridine]-6,6′-dicarboxylate
and 4,4′-bpy is 4,4′-bipyridine), was synthesized and
thoroughly characterized with spectroscopic, X-ray, and electrochemical
techniques. This oligomer exhibits strong affinity for graphitic materials
through CH−π interactions and thus easily anchors on
multiwalled carbon nanotubes (CNT), generating the molecular hybrid
material
10@CNT
. The latter acts as a water oxidation
catalyst and converts to a new species,
10′(H
2
O)
2
@CNT
, during the electrochemical oxygen evolution process
involving solvation and ligand reorganization facilitated by the interactions
of molecular Ru catalyst and the surface. This heterogeneous system
has been shown to be a powerful and robust molecular hybrid anode
for electrocatalytic water oxidation into molecular oxygen, achieving
current densities in the range of 200 mA/cm
2
at pH 7 under
an applied potential of 1.45 V vs NHE. The remarkable long-term stability
of this hybrid material during turnover is rationalized based on the
supramolecular interaction of the catalyst with the graphitic surface.
Conformational changes induced by ligand substituents in macrocyclic Ru complexes strongly affect their chemical and photocatalytic efficiencies in water oxidation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.