The association between virologic response and human immunodeficiency virus type 1 (HIV-1) subtype was investigated in 113 HIV-1–infected children randomly assigned to receive zidovudine plus ...lamivudine, zidovudine plus abacavir, or lamivudine plus abacavir in the Paediatric European Network for Treatment of AIDS (PENTA) 5 trial. Symptomatic children (n=68) also received nelfinavir; asymptomatic children (n=45) were randomly assigned to receive nelfinavir or placebo. HIV-1 subtypes A, B, C, D, F, G, H, A/E, and A/G were found in 15%, 41%, 16%, 9%, 5%, 2%, 1%, 5%, and 7% of the children, respectively. Resistance assay failure rates were higher for non-B subtypes than for B subtypes (genotype, P=.01; phenotype, P=.02). HIV-1 subtype was not associated with virologic response at 24 and 48 weeks after initiation of treatment. No differences were observed in the frequency of development of resistance mutations L90M (P=1.00) and D30N (P=.61) in B and non-B viruses. In conclusion, no evidence that subtype determined virologic response to therapy was found
The research activity of our group in the last few years has mainly been devoted to the study of ultrathin vanadium oxide films deposited on a (110)-oriented TiO sub(2) single crystal, in order to ...prepare systems which may be largely thought of as simplified models for the investigation of the structure/properties relationships in real world catalysts, sensing and optical devices. The main objective of our work consists of setting up reproducible synthesis routes for the deposition of vanadium oxide ultrathin films on TiO sub(2) (110), through strict control of the reaction parameters. The films obtained are then characterised from a chemical, electronic and structural point of view, and their properties are compared to those of their bulk-related phases. Results are presented concerning growth procedures and structural and electronic properties of vanadium oxide ultrathin films on titania, with a stoichiometry ranging from VO sub(2), down to approximately VO. In particular, it will be shown that the oxidation product of metallic vanadium in an oxygen or water atmosphere (in the 10 super(-6) mbar range) retains the rutile lattice structure typical of stoichiometric VO sub(2), despite the increasing degree of oxygen defectiveness and the electronic properties, very similar to those pertaining to bulk V sub(2)O sub(3). The peculiar behaviour of vanadium oxide on titania demonstrates how important the epitaxial influence of the substrate is on the nature of the overlayer. These results could represent a good starting point to understand why vanadium oxides on TiO sub(2) show an enhanced catalytic activity and selectivity in many industrially relevant reactions. copyright 2001 Elsevier Science B.V. All rights reserved.
The research activity of our group in the last few years has mainly been devoted to the study of ultrathin vanadium oxide films deposited on a (110)-oriented TiO
2 single crystal, in order to prepare ...systems which may be largely thought of as simplified models for the investigation of the structure/properties relationships in real world catalysts, sensing and optical devices. The main objective of our work consists of setting up reproducible synthesis routes for the deposition of vanadium oxide ultrathin films on TiO
2 (110), through strict control of the reaction parameters. The films obtained are then characterised from a chemical, electronic and structural point of view, and their properties are compared to those of their bulk-related phases. Results are presented concerning growth procedures and structural and electronic properties of vanadium oxide ultrathin films on titania, with a stoichiometry ranging from VO
2, down to approximately VO. In particular, it will be shown that the oxidation product of metallic vanadium in an oxygen or water atmosphere (in the 10
−6 mbar range) retains the rutile lattice structure typical of stoichiometric VO
2, despite the increasing degree of oxygen defectiveness and the electronic properties, very similar to those pertaining to bulk V
2O
3. The peculiar behaviour of vanadium oxide on titania demonstrates how important the epitaxial influence of the substrate is on the nature of the overlayer. These results could represent a good starting point to understand why vanadium oxides on TiO
2 show an enhanced catalytic activity and selectivity in many industrially relevant reactions.
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