How to control the recombinant prion protein adhesion for successful storage through modification of surface properties

Depletion of neuroproteins on the inner walls of storage tubes influences the accuracy of tests used for identification of various neurodegenerative disorders. In this paper, a strategy is described for surface modification of Eppendorf tubes leading to non-adhesive properties towards the recombinant human prion proteins (PrPrec(hum)). Tubes were pre-activated by helium plasma and grafted with three diverse coatings: pure poly(N-isopropylacrylamide) (PNIPAM), PNIPAM admixed with either neutral PEG(20)sorbitan monolaurate (PEG(20)) or positively charged cetyl trimethylammonium bromide (CTAB) at varying plasma activation times and polymer to surfactant ratios. New functionalized surfaces were analyzed by goniometry, streaming potential measurement and X-ray photoelectron spectroscopy, whereas the protein adhesion was monitored by enzyme linked immunosorbent assays and confocal microscopy. The mapping of PrPrec(hum) adhesion associated with surface analyses enabled us to determine that no or negligible depletion of PrPrec(hum) can be obtained by surfaces possessing basic component in the range between 50 and 60 mJ m(-2) and streaming potential ζ(7.4) - -50 mV.

Suppression of tritium retention in remote areas of ITER by nonperturbative reactive gas injection

A technique based on reactive gas injection in the afterglow region of the divertor plasma is proposed for the suppression of tritium-carbon codeposits in remote areas of ITER when operated with carbon-based divertor targets. Experiments in a divertor simulator plasma device indicate that a 4  nm/min deposition can be suppressed by addition of 1  Pa·m³ s⁻¹ ammonia flow at 10 cm from the plasma. These results bolster the concept of nonperturbative scavenger injection for tritium inventory control in carbon-based fusion plasma devices, thus paving the way for ITER operation in the active phase under a carbon-dominated, plasma facing component background.

EXAFS study of NiAl in thin films

Technologically important coatings of transition-metal aluminides call be produced by thermal or ion beam mixing of multilayer structures sputter deposited on substrates. The quantitative detection of constituents by depth profiling is sufficient to establish the efficiency of mixing methods. However, to decide whether a mixture of nanoparticles or a stoichiometric alloy is formed, EXAFS analysis of the local atomic neighborhood in the film is required. Ni K edge EXAFS spectra are measured on a series of samples of Ni/Al multilayer on Si(111) surface, after ion mixing at different substrate temperatures. The spectra show that with increasing temperature the nickel aluminide phase gradually substitutes the Ni fcc metal phase.

Aseptic meningitis after vaccination against measles and mumps

This retrospective study (1979 to 1986) investigated the possible etiologic relationship between vaccination and aseptic meningitis in 115 hospitalized children who became ill within 30 days of vaccination with the Leningrad 3 strain of mumps virus and the Edmonston-Zagreb strain of measles virus. The etiologic viral diagnosis was based on serologic tests and the isolation of virus from cell cultures which distinguished between attenuated and "virulent" mumps virus. The incidence of mumps vaccine-associated meningitis was 1/1000 vaccine recipients. In 92% of children the incubation period was 11 to 25 days and 28% had associated swelling of the salivary glands. Sixteen cases (13.9%) had a positive cerebrospinal fluid culture (attenuated mumps virus, 6 cases; "virulent" mumps virus, 7 cases; echoviruses, 3 cases). Clustering of cases, seasonal occurrence and age of the patients suggested causal relationship with the vaccination in the majority of children. In 4 patients with attenuated virus isolation from cerebrospinal fluid the incubation period ranged from 17 to 20 days. Clinical findings did not differ from natural mumps meningitis. The course was uncomplicated and at discharge the patients had no sequelae. Measles virus was never found as a cause of the meningitis. The mumps vaccine virus should be recognized as one of the causative agents of aseptic meningitis in countries where less attenuated mumps vaccine is used.