Alkali-ion-crown ether in art and conservation: the applied bioinorganic chemistry approach.

Dried varnish is rich in many ester moieties, which may be broken down into small, soluble compounds by esterase activity or alkaline hydrolysis. Two methods for varnish removal have been developed, including the treatment of either lipase or RbOH / PEG-400 crown ether which allow aged oil varnishes or paint coverings to be removed or thinned. These techniques are designed to proceed in a controlled manner without damaging lower paint or base layers.

TOF-SIMS investigations on weathered silver surfaces.

Silver-coated quartz crystal microbalance (QCM) disks were treated under different environmental conditions (including changes in parameters such as relative humidity (%RH) and SO(2)/H(2)S content) in atmospheres of synthetic air and pure N(2) for 24 h in a weathering chamber. The corroded surfaces were subjected to depth profiling by a time of flight (TOF) secondary ion mass spectrometry (SIMS) instrument, equipped with a Bi(+) analysis gun and Cs(+) sputter gun. The evaluation of the in-depth distribution of several elements and species provides evidence for the formation of a corrosion layer containing Ag(2)SO(3), even in the absence of oxidizing agents, such as H(2)O(2) or NO(2).

Oxygen-dependent regulation of in vivo replication of simian virus 40 DNA is modulated by glucose.

Simian virus 40 (SV40)-infected CV1 cells exposed to hypoxia show an inhibition of viral replication. Reoxygenation after several hours of hypoxia results in new initiations followed by a nearly synchronous round of SV40 replication. In this communication, we examined the effect of glucose on inhibition of viral DNA replication under hypoxia.