32 research outputs found
Anomalous Workfunction Anisotropy in Ternary Acetylides
Anomalous anisotropy of workfunction values in ternary alkali metal
transition metal acetylides is reported. Workfunction values of some
characteristic surfaces in these emerging semiconducting materials may differ
by more than 2 eV as predicted by Density Functional Theory
calculations. This large anisotropy is a consequence of the relative
orientation of rod-like [MC] negatively charged polymeric
subunits and the surfaces, with M being a transition metal or metalloid element
and C refers to the acetylide ion C, with the rods embedded
into an alkali cation matrix. It is shown that the conversion of the seasoned
CsTe photo-emissive material to ternary acetylide CsTeC
results in substantial reduction of its 3 eV workfunction down to
1.71-2.44 eV on the CsTeC(010) surface while its high quantum yield
is preserved. Similar low workfunction values are predicted for other ternary
acetylides as well, allowing for a broad range of applications from improved
electron- and light-sources to solar cells, field emission displays, detectors
and scanners.Comment: Accepted for publication in Phys. Rev.
Deep-Sea Nematodes Actively Colonise Sediments, Irrespective of the Presence of a Pulse of Organic Matter: Results from an In-Situ Experiment
A colonisation experiment was performed in situ at 2500 m water depth at the
Arctic deep-sea long-term observatory HAUSGARTEN to determine the response of
deep-sea nematodes to disturbed, newly available patches, enriched with organic
matter. Cylindrical tubes,laterally covered with a 500 µm mesh, were
filled with azoic deep-sea sediment and 13C-labelled food sources
(diatoms and bacteria). After 10 days of incubation the tubes were analysed for
nematode response in terms of colonisation and uptake. Nematodes actively
colonised the tubes,however with densities that only accounted for a maximum of
2.13% (51 ind.10 cm−2) of the ambient nematode
assemblages. Densities did not differ according to the presence or absence of
organic matter, nor according to the type of organic matter added. The fact that
the organic matter did not function as an attractant to nematodes was confirmed
by the absence of notable 13C assimilation by the colonising
nematodes. Overall, colonisationappears to be a process that yields reproducible
abundance and diversity patterns, with certain taxa showing more efficiency.
Together with the high variability between the colonising nematode assemblages,
this lends experimental support to the existence of a spatio-temporal mosaic
that emerges from highly localised, partially stochastic community dynamics
Pharmacologically Reversible, Loss of Function Mutations in the tm2 and tm4 Inner Pore Helices of Trek-1 k2p Channels
A better understanding of the gating of TREK two pore domain potassium (K2P) channels and their activation by compounds such as the negatively charged activator, flufenamic acid (FFA) is critical in the search for more potent and selective activators of these channels. Currents through wild-type and mutated human K2P channels expressed in tsA201 cells were measured using whole-cell patch-clamp recordings in the presence and absence of FFA. Mutation of the TM2.6 residue of TREK-1 to a phenylalanine (G171F) and a similar mutation of TM4.6 (A286F) substantially reduced current through TREK-1 channels. In complementary experiments, replacing the natural F residues at the equivalent position in TRESK channels, significantly enhanced current. Known, gain of function mutations of TREK-1 (G137I, Y284A) recovered current through these mutated channels. This reduction in current could be also be reversed pharmacologically, by FFA. However, an appropriate length MTS (MethaneThioSulfonate) cross-linking reagent (MTS14) restricted the activation of TREK-1_A286C channels by repeated application of FFA. This suggests that the cross-linker stabilises the channel in a conformation which blunts FFA activation. Pharmacologically reversible mutations of TREK channels will help to clarify the importance of these channels in pathophysiological conditions such as pain and depression
Highly Dynamic Chalcogen Chains in Silver(I) (Poly)Chalcogenide Halides: a New Concept for Thermoelectrics?
Flavanols and Methylxanthines in Commercially Available Dark Chocolate: A Study of the Correlation with Nonfat Cocoa Solids
Erfolgreiche Umsetzung dienstleistungsorientierter Strategien von Industriegüterunternehmen
Industrielle Dienstleistungen bieten Industriegüterunternehmen eine große Chance,
die Beziehungen zu ihren Kunden zu stärken und somit den Unternehmenserfolg zu
steigern. Damit diese Chance wirkungsvoll ausgeschöpft werden kann, ist es
notwendig, dass sich diese Unternehmen mit wichtigen Aspekten einer
Dienstleistungsstrategie auseinandersetzen. Hierzu zählen die Breite des Angebots
und die Intensität der Vermarktung industrieller Dienstleistungen. Darüber hinaus ist
die Frage, wie die gewählte Dienstleistungsstrategie erfolgreich umgesetzt werden
kann, von besonderer Bedeutung. Die vorliegende Arbeit setzt sich auf Basis einer
branchenübergreifenden Studie mit dieser Frage auseinander. Dabei konnte die theoretisch abgeleitete Erfolgsrelevanz ienstleistungsorientiert gestalteter Unternehmensführungsteilsysteme
bei der Implementierung von Dienstleistungsstrategien belegt werden