Critical behavior of thermopower and conductivity at the metal-insulator transition in high-mobility Si-MOSFET's

This letter reports thermopower and conductivity measurements through the metal-insulator transition for 2-dimensional electron gases in high mobility Si-MOSFET's. At low temperatures both thermopower and conductivity show critical behavior as a function of electron density which is very similar to that expected for an Anderson transition. In particular, when approaching the critical density from the metallic side the diffusion thermopower appears to diverge and the conductivity vanishes. On the insulating side the thermopower shows an upturn with decreasing temperature.Comment: 4 pages with 3 figure

Surface passivation of crystalline silicon by Cat-CVD amorphous and nanocrystalline thin silicon films

In this work, we study the electronic surface passivation of crystalline silicon with intrinsic thin silicon films deposited by Catalytic CVD. The contactless method used to determine the effective surface recombination velocity was the quasi-steady-state photoconductance technique. Hydrogenated amorphous and nanocrystalline silicon films were evaluated as passivating layers on n- and p-type float zone silicon wafers. The best results were obtained with amorphous silicon films, which allowed effective surface recombination velocities as low as 60 and 130 cms -1 on p- and n-type silicon, respectively. To our knowledge, these are the best results ever reported with intrinsic amorphous silicon films deposited by Catalytic CVD. The passivating properties of nanocrystalline silicon films strongly depended on the deposition conditions, especially on the filament temperature. Samples grown at lower filament temperatures (1600 °C) allowed effective surface recombination velocities of 450 and 600 cms -1 on n- and p-type silicon

Behavior of the thermopower in amorphous materials at the metal-insulator transition

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Lineages, Sub-Lineages and Variants of Enterovirus 68 in Recent Outbreaks

Enterovirus 68 (EV68) was first isolated in 1962. Very few cases of EV68 infection were described over the ensuing 40 years. However, in the past few years, an increase in severe respiratory tract infections associated with EV68 has been reported. We identified two clusters of EV68 infection in South London, UK, one each in the autumn/winters of 2009 and 2010. Sequence comparison showed significant homology of the UK strains with those from other countries including the Netherlands, Japan and the Philippines, which reported EV68 outbreaks between 2008 and 2010. Phylogenetic analysis of all available VP1 sequences indicated the presence of two modern EV68 lineages. The 2010 UK strains belonged to lineage 2. Lineage 1 could be further divided into two sub-lineages: some Japanese and Dutch strains collected between 2004 and 2010 form a distinct sub-lineages (sub-lineage 1.1), whereas other strains from the UK, Japan, Netherlands and Philippines collected between 2008 and 2010 represent sub-lineage 1.2. The UK 2009 strains together with several Dutch and Japanese strains from 2009/2010 represents one variant (1.2.1), whereas those from the Philippines a second variant (1.2.2). Based on specific deletions and substitutions, we suggest rules for the assignment of lineages and sub-lineages. Molecular epidemiological analysis indicates rapid recent evolution of EV68 and this may explain the recent findings of a global resurgence of EV68. Continuous global monitoring of the clinical and molecular epidemiology of EV68 is recommended

Thiolutin is a zinc chelator that inhibits the Rpn11 and other JAMM metalloproteases

Thiolutin is a disulfide-containing antibiotic and anti-angiogenic compound produced by Streptomyces. Its biological targets are not known. We show that reduced thiolutin is a zinc chelator that inhibits the JAB1/MPN/Mov34 (JAMM) domain–containing metalloprotease Rpn11, a deubiquitinating enzyme of the 19S proteasome. Thiolutin also inhibits the JAMM metalloproteases Csn5, the deneddylase of the COP9 signalosome; AMSH, which regulates ubiquitin-dependent sorting of cell-surface receptors; and BRCC36, a K63-specific deubiquitinase of the BRCC36-containing isopeptidase complex and the BRCA1–BRCA2-containing complex. We provide evidence that other dithiolopyrrolones also function as inhibitors of JAMM metalloproteases

Thermokraft von Sb/Au-Doppelschichten und amorphen Au_xSb_1_0_0_-_x-Legierungen

The work in hand reports measurements for determination of the thermal e.m.f. and resistance of Sb/Au twin layers and finely crystalline Au films as a function of thickness and temperature. In addition, supplementing measurements are reported showing the temperature dependence of the thermal e.m.f. and resistance of homogenous, amorphous Au_xSb_1_0_0_-_x alloys of 7.5 at%#<=#x#<=#80 at%. The electronic performance of the Sb/Au twin layers has been studied applying photoelectron spectrosocpy. (orig.)In der vorliegenden Arbeit wird ueber Messungen der Temperatur- und Dickenabhaengigkeit der Thermokraft und des Widerstands von Sb/Au-Doppelschichten und feinkristallinen Au-Schichten berichtet. Ergaenzend dazu wurden Messungen der Temperaturabhaengigkeit der Thermokraft und des Widerstands von homogenen amorphen Au_xSb_1_0_0_-_x-Legierungen im Bereich 7.5 at%#<=#x#<=#80 at% durchgefuehrt. Zusaetzlich wurden die elektronischen Eigenschaften der Sb/Au-Doppelschichten mit Hilfe von Photoelektronenspektroskopie (UPS) untersucht. (orig.)SIGLEAvailable from TIB Hannover: H94B468 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Functional Independence Measurement Scale: Analysis of Variables to Determine Predictability to Stroke Patient\u27s Discharge Site

The purpose was to define subsets of variables that are found within the Functional Independence Measurement (FIM) scale that demonstrate a high predictability to right cerebral vascular accident (CVA) patient\u27s discharge site, including home, foster home, and skilled nursing facility. The researchers wanted to find if gait, along with other subsets, has a high prediction to discharge site than overall FIM admission and discharge scores together and separately.; Gait did not show a higher prediction to discharge site compared with subsets of FIM variables and overall FIM admission and discharge scores, together and separately. However, other subsets were found to demonstrate a high prediction to discharge site. Subset one, which includes activities of daily living, and subset five, which includes mobility and cognitive items, demonstrated a high prediction to discharge site. Therefore it is possible to develop a shortened screening tool to decrease the time it takes to determine the most appropriate discharge site

Human autoantibodies against early endosome antigen-1 enhance excitatory synaptic transmission

12 páginas, 6 figuras.Early endosome antigen 1 (EEA1), a peripheral membrane protein associated with the cytoplasmic face of early endosomes, controls vesicle fusion during endocytosis, as extensively studied in non-neuronal cells. In neurons, early endosomes are involved in recycling of synaptic vesicles and neurotransmitter receptors. Since certain patients bearing autoantibodies that target EEA1 develop neurological disease, we studied the subcellular distribution of EEA1 in neurons and the effect on neurotransmission of purified immunoglobulins from the serum of a patient bearing EEA1 autoantibodies. EEA1 was localized in the soma and in the postsynaptic nerve terminals. Electrophysiological recordings in hippocampal slices including purified EEA1 antibodies in the patch pipette solution, revealed a run-up of AMPA, N-methyl-d-aspartate and kainate receptor-mediated excitatory post-synaptic currents recorded from CA3 pyramidal neurons, which was absent in the recordings obtained in the presence of control human immunoglobulin G. Inclusion of human EEA1 antibodies had no effect on inhibitory post-synaptic responses. Recordings in the presence of a dominant-negative C-terminal EEA1 deletion mutant produced a similar effect as observed with human anti-EEA1 antibodies. This specific effect on the excitatory synaptic transmission may be due to the impairment of internalization of specific glutamate receptors and their subsequent accumulation in the synapse. These results may account for the neurological deficits observed in some patients developing EEA1 autoantibodies.This work was supported by grants to J.L. from the MCYT (BFI2003-00161) and the European Union (QLG3- CT2001-00929). S.S. was a recipient of a fellowship from the Program of Foreign Doctors and Technologists in Spain (MCYT) and currently is an I3P Program CSIC Research Fellow.Peer reviewe