10 research outputs found
Magnetic Coupling of Gd 3 N@C 80 Endohedral Fullerenes to a Substrate
Using magnetic endohedral fullerenes for molecular spintronics requires
control over their encapsulated magnetic moments. We show by field-dependent
x-ray magnetic circular dichroism measurements of Gd3N@C80 endohedral
fullerenes adsorbed on a Cu surface that the magnetic moments of the
encapsulated Gd atoms lie in a 4f7 ground state and couple ferromagnetically
to each other. When the molecules are in contact with a ferromagnetic Ni
substrate, we detect two different Gd species. The more abundant one couples
antiferromagnetically to the Ni, whereas the other one exhibits a stronger and
ferromagnetic coupling to the substrate. Both of these couplings to the
substrate can be explained by an indirect exchange mechanism mediated by the
carbon cage. The origin of the distinctly different behavior may be attributed
to different orientations and thus electronic coupling of the carbon cage to
the substrate, as revealed by scanning tunneling microscopy of the fullerenes
on Cu
Lethal hemorrhage from a uretericâarterialâenteric fistula diagnosed by postmortem CT angiography
Use of post-mortem computed tomography in disaster victim identification. Updated positional statement of the members of the disaster victim identification working group of the International Society of Forensic Radiology and Imaging; July 2019
Interception of Small Particles by Flocculent Structures, Sessile Ciliates, and the Basic Layer of a Wastewater Biofilm
We investigated attachment processes of hydrophobic and hydrophilic particles (diameter = 1 ÎŒm) to mature biofilms grown on clay marbles in a sequencing batch biofilm reactor. During a treatment cycle with filtered wastewater containing different fluorescent beads, the progression of particle density in various biofilm compartments (carrier biofilm, basic biofilm layer, biofilm flocs, and sessile ciliates) was determined by flow cytometry, confocal laser scanning microscopy and automated image analysis. Particles were almost completely removed from wastewater by typical processes of particle retention: up to 58% of particles attached to clay marbles, up to 15% were associated with suspended flocs, and up to 10% were ingested by sessile ciliates. Ingestion of particles by ciliates was exceptionally high immediately after wastewater addition (1,200 particles grazer(â1) h(â1)) and continued until approximately 14% of the water had been cleared by ciliate filter feeding. Most probably, ciliate bioturbation increases particle sorption to the basic biofilm. Backwashing of the reactor detached pieces of biofilm and thus released approximately 50% of the particles into rinsing water. Clay marbles in the upper part of the reactor were more efficiently abraded than in the lower part. No indications for selective attachment of the applied hydrophobic and hydrophilic beads were found. As a consequence of interception patterns, organisms at elevated biofilm structures are probably major profiteers of wastewater particles; among them, ciliates may be of major importance because of their highly active digestive food vacuoles