Electron and hole injection barriers between silicon substrate and RF magnetron sputtered In2O3 : Er films

In2O3 : Er films have been synthesized on silicon substrates by RF magnetron sputter deposition. The currents through the synthesized metal/oxide/semiconductor (MOS) structures (Si/In2O3 : Er/In-contact) have been measured for n and p type conductivity silicon substrates and described within the model of majority carrier thermoemission through the barrier, with bias voltage correction to the silicon potential drop. The electron and hole injection barriers between the silicon substrate and the film have been found to be 0.14 and 0.3 eV, respectively, by measuring the temperature dependence of the forward current at a low sub-barrier bias. The resulting low hole injection barrier is accounted for by the presence of defect state density spreading from the valence band edge into the In2O3 : Er band gap to form a hole conduction channel. The presence of defect state density in the In2O3 : Er band gap is confirmed by photoluminescence data in the respective energy range 1.55–3.0 eV. The band structure of the Si/In2O3 : Er heterojunction has been analyzed. The energy gap between the In2O3 : Er conduction band electrons and the band gap conduction channel holes has been estimated to be 1.56 eV

Preclinical and Clinical Development of a YFV 17 D-Based Chimeric Vaccine against West Nile Virus

Substantial success has been achieved in the development and implementation of West Nile (WN) vaccines for horses; however, no human WN vaccines are approved. This review focuses on the construction, pre-clinical and clinical characterization of ChimeriVax-WN02 for humans, a live chimeric vaccine composed of a yellow fever (YF) 17D virus in which the prM-E envelope protein genes are replaced with the corresponding genes of the WN NY99 virus. Pre-clinical studies demonstrated that ChimeriVax-WN02 was significantly less neurovirulent than YF 17D in mice and rhesus and cynomolgus monkeys. The vaccine elicited neutralizing antibody titers after inoculation in hamsters and monkeys and protected immunized animals from lethal challenge including intracerebral inoculation of high dose of WN NY99 virus. Safety, viremia and immunogenicity of ChimeriVax-WN02 were assessed in one phase I study and in two phase II clinical trials. No safety signals were detected in the three clinical trials with no remarkable differences in incidence of adverse events (AEs) between vaccine and placebo recipients. Viremia was transient and the mean viremia levels were low. The vaccine elicited strong and durable neutralizing antibody and cytotoxic T cell responses. WN epidemiology impedes a classical licensure pathway; therefore, innovative licensure strategies should be explored

Electron and hole injection barriers between silicon substrate and RF magnetron sputtered In2O3 : Er films

In2O3 : Er films have been synthesized on silicon substrates by RF magnetron sputter deposition. The currents through the synthesized metal/oxide/semiconductor (MOS) structures (Si/In2O3 : Er/In-contact) have been measured for n and p type conductivity silicon substrates and described within the model of majority carrier thermoemission through the barrier, with bias voltage correction to the silicon potential drop. The electron and hole injection barriers between the silicon substrate and the film have been found to be 0.14 and 0.3 eV, respectively, by measuring the temperature dependence of the forward current at a low sub-barrier bias. The resulting low hole injection barrier is accounted for by the presence of defect state density spreading from the valence band edge into the In2O3 : Er band gap to form a hole conduction channel. The presence of defect state density in the In2O3 : Er band gap is confirmed by photoluminescence data in the respective energy range 1.55–3.0 eV. The band structure of the Si/In2O3 : Er heterojunction has been analyzed. The energy gap between the In2O3 : Er conduction band electrons and the band gap conduction channel holes has been estimated to be 1.56 eV

Application of replication-defective West Nile virus vector to non-flavivirus vaccine targets

The RepliVax vaccine platform(RV) is based on flavivirus genomes that are rationally attenuated by deletion. The self-limiting infection provided by RV has been demonstrated to be safe, highly immunogenic and efficacious for several vaccine candidates against flaviviruses. Here respiratory syncytial virus (RSV) F, influenza virus HA, and simian immunodeficiency virus (SIV) Env proteins were expressed in place of either prM-E or C-prM-E gene deletions of the West Nile (WN) virus genome. The resulting RV-RSV, -influenza and -SIV vaccine prototypes replicated efficiently in complementing helper cells expressing the WN structural proteins in trans. Expressed antigens exhibited correct post-translational processing and the RV recombinants were shown to be highly attenuated and immunogenic in mice, eliciting strong antigen-specific antibodies as well as detectable T-cell responses. These data support the utility of RV vectors for development of vaccines against non-flavivirus targets including rabies and HIV