The origin and direction of replication of the resistance plasmid R100.1 and its resistance transfer factor derivative, pAR132, were studied by electron microscopy autoradiography of partially denatured molecules and partial denaturation mapping of replicative intermediates. Results of these studies indicate the existence of an origin of replication at 8.8 kilobases on the R100 map. Replication...

Graphene is a two-dimensional form of graphite made up of a single layer of carbon atoms in a honeycomb lattice that has attracted tremendous interest for its novel physical properties. A key challenge that has emerged is how to synthesize large amounts of graphene (large area or mass) at low cost. The objective of this project is to explore an entirely new method to exfoliate graphene from com...

In a previous work we studied the influence of heat treatment on the molecular sieve properties of activated carbons prepared by chemical activation of lignin [1]. The thermal treatment modified the porous structure of the activated carbons, giving rise to solids that separate C6H6 from C6H12, CO2 from CH4 and O2 from N2 with a relative high selectivity. However, the heat treatment drastically ...

Hydroxyphenyl (H-type) and guaiacyl (G-type) lignin model polymers composed of the β–O–4 structure without –hydroxymethyl groups were synthesized. The chemical structures of the Hand G-type lignin models were characterized by Hand C-NMR, as well as MALDI-TOF/MS. The pyrolysis response was analyzed by means of TG-DTG, Py-GC/MS, and a tube furnace technique. H-, C-NMR, and MALDI-TOF/MS showed th...

A short, efficient synthesis of 22-hydroxyacuminatine, starting from a readily accessible hydroxy pyridone, is presented; key steps include a Heck coupling with methyl pentadienoate, a flash vacuum pyrolytic cyclization, and a Friedländer condensation.