Endogenous Retroviruses: Thierry Heidmann wins the 2009 Retrovirology prize

Thierry Heidmann wins the 2009 Retrovirology prize

Frequent and Recent Human Acquisition of Simian Foamy Viruses Through Apes' Bites in Central Africa

Human infection by simian foamy viruses (SFV) can be acquired by persons occupationally exposed to non-human primates (NHP) or in natural settings. This study aimed at getting better knowledge on SFV transmission dynamics, risk factors for such a zoonotic infection and, searching for intra-familial dissemination and the level of peripheral blood (pro)viral loads in infected individuals. We studied 1,321 people from the general adult population (mean age 49 yrs, 640 women and 681 men) and 198 individuals, mostly men, all of whom had encountered a NHP with a resulting bite or scratch. All of these, either Pygmies (436) or Bantus (1085) live in villages in South Cameroon. A specific SFV Western blot was used and two nested PCRs (polymerase, and LTR) were done on all the positive/borderline samples by serology. In the general population, 2/1,321 (0.2%) persons were found to be infected. In the second group, 37/198 (18.6%) persons were SFV positive. They were mostly infected by apes (37/39) FV (mainly gorilla). Infection by monkey FV was less frequent (2/39). The viral origin of the amplified sequences matched with the history reported by the hunters, most of which (83%) are aged 20 to 40 years and acquired the infection during the last twenty years. The (pro)viral load in 33 individuals infected by a gorilla FV was quite low (<1 to 145 copies per 105 cells) in the peripheral blood leucocytes. Of the 30 wives and 12 children from families of FV infected persons, only one woman was seropositive in WB without subsequent viral DNA amplification. We demonstrate a high level of recent transmission of SFVs to humans in natural settings specifically following severe gorilla bites during hunting activities. The virus was found to persist over several years, with low SFV loads in infected persons. Secondary transmission remains an open question

Ethanol decomposition on Co(0001):C-O Bond scission on a close-packed cobalt surface

Recently there has been a renewed interest in Co-catalyzed Fischer- Tropsch synthesis (FTS) from natural gas, coal, and biomass, because it offers a realistic alternative to crude oil as a source of transportation fuels. Efforts to understand the FT mechanism on the atomic level have mainly focused on theoretical methods, whereas experimental surface science results have only had little impact on the understanding of the mechanism. An essential step in any FT mechanism is scission of the C-O bond. On a flat Co(0001) surface direct dissociation of the CO molecule is practically impossible at FTS conditions. We have found for the first time experimentally that the C-O bond can be broken at 350 K even on the relatively inert Co(0001) surface if a CxHy group and a hydrogen atom are attached to the C-end of the C-O moiety

The impact of cobalt aluminate formation on the deactivation of cobalt-based Fischer–Tropsch synthesis catalysts

It has been reported that cobalt aluminate formation is a cause of deactivation during Fischer–Tropsch synthesis (FTS), as it forms at the expense of active cobalt and is irreducible during FTS. To study this quantitatively, wax-coated Co/Pt/Al2O3 catalyst samples were removed periodically from an extended demonstration reactor FTS run operated at commercially relevant conditions and analysed with X-ray Absorption Near Edge Spectroscopy (XANES). With XANES, wax protected spent samples could be analysed in a pseudo in-situ mode. Under commercially relevant FTS conditions the catalyst undergoes reduction and minimal amounts of cobalt aluminate were found. It is proposed that the cobalt aluminate is formed from the residual CoO present in the catalyst after reduction. Additionally, the formation of aluminate was investigated with XANES and X-ray photoelectron spectroscopy (XPS) and TPR-MS on catalysts taken from laboratory continuous stirred tank reactor (CSTR) runs with varying water partial pressure (1–10 bar). Even at high water partial pressures (PH2O=10 bar, PH2O/PH2=2.2) only around 10% cobalt aluminate is formed while the metallic fraction of cobalt still increased compared to the fresh catalyst. The work shows that cobalt aluminate formation during FTS at realistic conditions is not a major deactivation mechanism