7,766 research outputs found
Failure of classical elasticity in auxetic foams
A recent derivation [P.H. Mott and C.M. Roland, Phys. Rev. B 80, 132104
(2009).] of the bounds on Poisson's ratio, v, for linearly elastic materials
showed that the conventional lower limit, -1, is wrong, and that v cannot be
less than 0.2 for classical elasticity to be valid. This is a significant
result, since it is precisely for materials having small values of v that
direct measurements are not feasible, so that v must be calculated from other
elastic constants. Herein we measure directly Poisson's ratio for four
materials, two for which the more restrictive bounds on v apply, and two having
values below this limit of 0.2. We find that while the measured v for the
former are equivalent to values calculated from the shear and tensile moduli,
for two auxetic materials (v < 0), the equations of classical elasticity give
inaccurate values of v. This is experimental corroboration that the correct
lower limit on Poisson's ratio is 0.2 in order for classical elasticity to
apply.Comment: 9 pages, 2 figure
Electronic Structure of Electron-doped Sm1.86Ce0.14CuO4: Strong `Pseudo-Gap' Effects, Nodeless Gap and Signatures of Short Range Order
Angle resolved photoemission (ARPES) data from the electron doped cuprate
superconductor SmCeCuO shows a much stronger pseudo-gap
or "hot-spot" effect than that observed in other optimally doped -type
cuprates. Importantly, these effects are strong enough to drive the
zone-diagonal states below the chemical potential, implying that d-wave
superconductivity in this compound would be of a novel "nodeless" gap variety.
The gross features of the Fermi surface topology and low energy electronic
structure are found to be well described by reconstruction of bands by a
order. Comparison of the ARPES and optical data from
the sample shows that the pseudo-gap energy observed in optical data is
consistent with the inter-band transition energy of the model, allowing us to
have a unified picture of pseudo-gap effects. However, the high energy
electronic structure is found to be inconsistent with such a scenario. We show
that a number of these model inconsistencies can be resolved by considering a
short range ordering or inhomogeneous state.Comment: 5 pages, 4 figure
Replicated Data Types
International audienceA CRDT is an abstract data type that implements some familiar object, such as a counter, a set or a sequence. Internally, a CRDT is replicated, to provide reliability, availability. A CRDT supports concurrent updates, and encapsulates some strategy that provably ensures that replicas of the CRDT will converge despite this concurrency
The Hamiltonian boundary term and quasi-local energy flux
The Hamiltonian for a gravitating region includes a boundary term which
determines not only the quasi-local values but also, via the boundary variation
principle, the boundary conditions. Using our covariant Hamiltonian formalism,
we found four particular quasi-local energy-momentum boundary term expressions;
each corresponds to a physically distinct and geometrically clear boundary
condition. Here, from a consideration of the asymptotics, we show how a
fundamental Hamiltonian identity naturally leads to the associated quasi-local
energy flux expressions. For electromagnetism one of the four is distinguished:
the only one which is gauge invariant; it gives the familiar energy density and
Poynting flux. For Einstein's general relativity two different boundary
condition choices correspond to quasi-local expressions which asymptotically
give the ADM energy, the Trautman-Bondi energy and, moreover, an associated
energy flux (both outgoing and incoming). Again there is a distinguished
expression: the one which is covariant.Comment: 12 pages, no figures, revtex
The use of stained cytologic direct smears for ALK gene rearrangement analysis of lung adenocarcinoma
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100150/1/cncy21286.pd
Up-regulation of adipogenin, an adipocyte plasma transmembrane protein, during adipogenesis
The original publication is available at www.springerlink.com.ArticleMOLECULAR AND CELLULAR BIOCHEMISTRY. 276(1-2): 133-141 (2005)journal articl
Application of immunocytochemistry and BRAF mutational analysis to direct smears of metastatic melanoma
BACKGROUND: The cytodiagnosis of melanoma in fine‐needle aspiration (FNA) specimens can be challenging, often requiring the use of immunocytochemistry. As constitutively activating mutations in the BRAF oncogene are present in at least 40% of melanomas, the use of FNA material to interrogate the BRAF mutational status is likely to increase. Because cell blocks, traditionally used for these studies, can occasionally exhibit insufficient tumor cellularity, the authors investigated the utility of direct smears for immunocytochemistry and BRAF mutational analysis. METHODS: Immunocytochemistry for S‐100, HMB‐45, and Mart‐1 was prospectively performed on direct smears in 17 FNAs of metastatic melanoma. Next, BRAF sequencing was performed using DNA isolated from archived Diff‐Quik–stained direct smears for 15 cases. In parallel, sequencing was performed using DNA obtained from corresponding cell blocks. RESULTS: S‐100 positivity in the tumor cells was observed in all 17 cases. HMB‐45 and Mart‐1 positivity was noted in 81% and 88% of cases, respectively. All 3 markers were positive in 76% of cases. Next, of the 15 archived melanoma FNAs tested, BRAF mutations were observed in 8 (53%); 5 and 3 melanomas harbored the V600E and V600K mutation, respectively. Corresponding cell blocks were also tested for all 15 cases, yielding concordant BRAF results in 14 (93%); 1 cell block yielded a false‐negative result. CONCLUSIONS: Cytologic direct smears represent a robust and valuable source of cellular material for immunocytochemistry and molecular studies, especially in instances in which inadequate cell block cellularity is anticipated or encountered. Cancer (Cancer Cytopathol) 2012. © 2011 American Cancer Society. This study demonstrates that direct smears represent a robust and valuable source of cellular material for ancillary studies used in the cytologic diagnosis of melanoma. Direct smears can be effectively used for confirmatory immunocytochemical studies and molecular assays designed to interrogate the BRAF mutational status of melanoma, especially in scenarios in which inadequate cell block cellularity is anticipated or encountered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90193/1/20180_ftp.pd
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