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Rolf Schuster

Publications and source records attributed to Rolf Schuster.

7 recordsLinked to original sources
PubMed2007

Electrochemical microstructuring with short voltage pulses.

The application of short (nanosecond) voltage pulses between a tool electrode and a work piece immersed in an electrolyte solution allows the three-dimensional machining of electrochemically active materials with submicrometer resolution. The method is based on the finite charging time constant of the double-layer capacitance, which varies approximately linearly with the local separation between the electrode surfaces. Hence, the polarization of the electrodes during short pulses and subsequent electrochemical reactions are confined to regions where the electrodes are in sufficiently close proximity. This Minireview describes the principles behind electrochemical micro-structuring with short voltage pulses, and its current achievements and limitations.

Journal Article↗
PubMed2004

Nanoscale probing of adsorbed species by tip-enhanced Raman spectroscopy.

Tip-enhanced Raman spectroscopy (TERS) is based on the optical excitation of localized surface plasmons in the tip-substrate cavity, which provides a large but local field enhancement near the tip apex. We report on TERS with smooth single crystalline surfaces as substrates. The adsorbates were CN- ions at Au(111) and malachite green isothiocyanate (MGITC) molecules at Au(111) and Pt(110) using either Au or Ir tips. The data analysis yields Raman enhancements of about 4 x 10(5) for CN- and up to 10(6) for MGITC at Au(111) with a Au tip, probing an area of less than 100 nm radius.

Journal Article↗
PubMed2003

Two-dimensional nanoscale self-assembly on a gold surface by spinodal decomposition.

The structure formation upon spinodal decomposition of a two-dimensional model system, a Au adatom gas on a Au(111) surface, was observed in situ by scanning tunneling microscopy (STM). A thermodynamically unstable state was prepared by applying microsecond voltage pulses to the STM tip in an electrochemical system, causing the random dissolution of Au atoms from the uppermost monolayer. Interconnected, labyrinthine island patterns were formed at Au coverages between 0.4 and 0.9 monolayer with dominating length scales lambda(m) of the order of a few nanometers.

Journal Article↗
PubMed2003

Molecular characterization and differentiation of opisthorchiid trematodes of the species Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1790) using polymerase chain reaction.

Adult specimens of the opisthorchiid liver fluke species Opisthorchis felineus and Metorchis bilis could be identified for the first time by molecular biological methods using species specific primers (OF and MB primers) in the polymerase chain reaction (PCR). The OF or MB primers were based on a part of the mitochondrial cytochrome c oxidase I gene. A specific product of approximately 200 bp could be amplified for O. felineus by means of the specific O. felineus primers. By contrast, the amplification of M. bilis DNA with MB primers produced a fragment of approximately 110 bp. A specificity of 100% could be demonstrated for both primer pairs. The sensitivities of the PCRs were 10 pg for the O. felineus DNA and 100 fg for the M. bilis DNA.

Animals↗
PubMed2003

A sero-epidemiological survey on the occurrence of opisthorchiid liver flukes in red foxes ( Vulpes vulpes) in Berlin, Germany.

Serum samples collected from red foxes in the city of Berlin between 1996 and 1999 were analysed for the presence of antibodies against Opisthorchis felineus and Metorchis bilis using an indirect ELISA. Out of 1,000 specimens, 30.6% and 46.5% reacted positively with specific O. felineus and M. bilis antigens, respectively. Seroprevalence in adult foxes was always higher than in juveniles. While no significant differences were observed in adult foxes throughout the period, in juvenile specimens seroprevalence declined from 1996 to 1997, then stayed at a comparable level in 1998 and increased in 1999. A varying availability of fresh cyprinid fish in different years seems to be the reason for changes in seroprevalence. By grouping the samples from juvenile foxes by season, antibodies against both Metorchis and Opisthorchis antigens started to appear between April and June, increased between July and September()and reached a level comparable to adult foxes in the October to December quarter. The lowest seroprevalence was found in Pankow, which is the district with the lowest share of the surface water.

Animals↗
PubMedDate not supplied

[The helminth fauna of indigenous white storks (Ciconia ciconia)].

120 carcasses of white storks originating from the federal countries Saxonia-Anhalt and Brandenburg where examined between 1994 and 2000 for internal parasites. The established parasite spectrum consisted of 8 trematode (Tylodelphis excavata, Chaunocephalus ferox, Cathemasia hians, Echinostoma revolutum, Echinoparyphium sp., Monilifer spinulosus, Ignavia ciconiae and Brachylaimus sp.), 4 cestode (Anomotaenia discoidea and 3 Hymenolepidae species) and at least 3 nematode species (Capillaria spp., Syngamus palustris and Contracaecum microcephalum). 5 of the helminths are considered to be stork specific. Considering host age groups the highest percentage of infected birds was found in adults.

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