767 research outputs found
p-wave superconductivity in iron-based superconductors
The possibility of p-wave pairing in superconductors has been proposed more than five decades ago, but has not yet been convincingly demonstrated. One difficulty is that some p-wave states are thermodynamically indistinguishable from s-wave, while others are very similar to d-wave states. Here we studied the self-field critical current of NdFeAs(O,F) thin films in order to extract absolute values of the London penetration depth, the superconducting energy gap, and the relative jump in specific heat at the superconducting transition temperature, and find that all the deduced physical parameters strongly indicate that NdFeAs(O,F) is a bulk p-wave superconductor. Further investigation revealed that single atomic layer FeSe also shows p-wave pairing. In an attempt to generalize these findings, we re-examined the whole inventory of superfluid density measurements in iron-based superconductors and show quite generally that single-band weak-coupling p-wave superconductivity is exhibited in iron-based superconductors. © 2019, The Author(s).Japan Science and Technology Corporation, JST: JPMJCR18J4Government Council on Grants, Russian FederationJapan Society for the Promotion of Science, JSPS: 16H04646АААА-А18-118020190104-3The authors thank Prof. Jeffery L. Tallon (Victoria University of Wellington, New Zealand) and Prof. Christian Bernhard (University of Fribourg, Switzerland) for helpful discussions, and also for reading and commenting on the manuscript. EFT is grateful for financial support provided by the state assignment of Minobrnauki of Russia (theme “Pressure” No. АААА-А18-118020190104-3) and by Act 211 of the Government of the Russian Federation, contract No. 02.A03.21.0006. KI and HI acknowledge support by the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Scientific Research (B) Grant Number 16H04646, as well as JST CREST Grant Number JPMJCR18J4. The Article Processing Charge for this publication was provided by Ural Federal University, Russia
Diversification and Intensification in Parallel {SAT} Solving
International audienceIn this paper, we explore the two well-known principles of diversification and intensification in portfolio-based parallel SAT solving. These dual concepts play an important role in several search algorithms including local search, and appear to be a key point in modern parallel SAT solvers. To study their trade-off, we define two roles for the computational units. Some of them classified as Masters perform an original search strategy, ensuring diversification. The remaining units, classified as Slaves are there to intensify their master's strategy. Several important questions have to be answered. The first one is what information should be given to a slave in order to intensify a given search effort? The second one is, how often, a subordinated unit has to receive such information? Finally, the question of finding the number of subordinated units along their connections with the search efforts has to be answered. Our results lead to an original intensification strategy which outperforms the best parallel SAT solver, and solves some open SAT instances
Two-nucleon emission in the longitudinal response
The contribution of the two-nucleon emission in the longitudinal response for
inclusive electron scattering reactions is studied. The model adopted to
perform the calculations is based upon Correlated Basis Function theory but it
considers only first order terms in the correlation function. The proper
normalization of the wave function is ensured by considering, in addition to
the usually evaluated two-point diagrams, also the three-point diagrams.
Results for the 12C nucleus in the quasi-elastic region are presented.Comment: 7 pages, 4 Postscript figure
Laser Machining by short and ultrashort pulses, state of the art and new opportunities in the age of the photons
An overview is given of the applications of short and ultrashort lasers in material processing. Shorter pulses reduce heat-affected damage of the material and opens new ways for nanometer accuracy. Even forty years after the development of the laser there is a lot of effort in developing new and better performing lasers. The driving force is higher accuracy at reasonable cost, which is realised by compact systems delivering short laser pulses of high beam quality. Another trend is the shift towards shorter wavelengths, which are better absorbed by the material and which allows smaller feature sizes to be produced. Examples of new products, which became possible by this technique, are given. The trends in miniaturization as predicted by Moore and Taniguchi are expected to continue over the next decade too thanks to short and ultrashort laser machining techniques. After the age of steam and the age of electricity we have entered the age of photons now
Electroinduced two-nucleon knockout and correlations in nuclei
We present a model to calculate cross sections for electroinduced two-nucleon
emission from finite nuclei. Short-range correlations in the wave functions and
meson-exchange contributions to the photoabsorption process are implemented.
Effects of the short-range correlations are studied with the aid of a
perturbation expansion method with various choices of the Jastrow correlation
function. The model is used to investigate the relative importance of the
different reaction mechanisms contributing to the A(e,epn) and A(e,epp)
process. Representative examples for the target nuclei C and O
and for kinematical conditions accessible with contemporary high-duty cycle
electron accelerators are presented. A procedure is outlined to calculate the
two-nucleon knockout contribution to the semi-exclusive (e,ep) cross
section. Using this technique we investigate in how far semi-exclusive
(e,ep) reactions can be used to detect high-momentum components in the
nuclear spectral function.Comment: 51 pages, Latex, uses epsf.sty and elsart.sty, 17 figures (in eps
format
Interactions of a boson in the component theory
The amplitudes for boson-boson and fermion-boson interactions are calculated
in the second order of perturbation theory in the Lobachevsky space. An
essential ingredient of the used model is the Weinberg's component
formalism for describing a particle of spin , recently developed
substantially. The boson-boson amplitude is then compared with the two-fermion
amplitude obtained long ago by Skachkov on the ground of the hamiltonian
formulation of quantum field theory on the mass hyperboloid, , proposed by Kadyshevsky. The parametrization of the amplitudes by
means of the momentum transfer in the Lobachevsky space leads to same spin
structures in the expressions of matrices for the fermion and the boson
cases. However, certain differences are found. Possible physical applications
are discussed.Comment: REVTeX 3.0 file. 12pp. Substantially revised version of IFUNAM
preprints FT-93-24, FT-93-3
Diabetes status and post-load plasma glucose concentration in relation to site-specific cancer mortality: findings from the original Whitehall study
ObjectiveWhile several studies have reported on the relation of diabetes status with pancreatic cancer risk, the predictive value of this disorder for other malignancies is unclear. Methods: The Whitehall study, a 25year follow-up for mortality experience of 18,006 men with data on post-challenge blood glucose and self-reported diabetes, allowed us to address these issues. Results: There were 2158 cancer deaths at follow-up. Of the 15 cancer outcomes, diabetes status was positively associated with mortality from carcinoma of the pancreas and liver, while the relationship with lung cancer was inverse, after controlling for a range of potential covariates and mediators which included obesity and socioeconomic position. After excluding deaths occurring in the first 10years of follow-up to examine the effect of reverse causality, the magnitude of the relationships for carcinoma of the pancreas and lung was little altered, while for liver cancer it was markedly attenuated. Conclusions: In the present study, diabetes status was related to pancreatic, liver, and lung cancer risk. Cohorts with serially collected data on blood glucose and covariates are required to further examine this area
Genome-Wide Association Study and Gene Expression Analysis Identifies CD84 as a Predictor of Response to Etanercept Therapy in Rheumatoid Arthritis
Anti-tumor necrosis factor alpha (anti-TNF) biologic therapy is a widely used treatment for rheumatoid arthritis (RA). It is unknown why some RA patients fail to respond adequately to anti-TNF therapy, which limits the development of clinical biomarkers to predict response or new drugs to target refractory cases. To understand the biological basis of response to anti-TNF therapy, we conducted a genome-wide association study (GWAS) meta-analysis of more than 2 million common variants in 2,706 RA patients from 13 different collections. Patients were treated with one of three anti-TNF medications: etanercept (n = 733), infliximab (n = 894), or adalimumab (n = 1,071). We identified a SNP (rs6427528) at the 1q23 locus that was associated with change in disease activity score (ΔDAS) in the etanercept subset of patients (P = 8×10-8), but not in the infliximab or adalimumab subsets (P>0.05). The SNP is predicted to disrupt transcription factor binding site motifs in the 3′ UTR of an immune-related gene, CD84, and the allele associated with better response to etanercept was associated with higher CD84 gene expression in peripheral blood mononuclear cells (P = 1×10-11 in 228 non-RA patients and P = 0.004 in 132 RA patients). Consistent with the genetic findings, higher CD84 gene expression correlated with lower cross-sectional DAS (P = 0.02, n = 210) and showed a non-significant trend for better ΔDAS in a subset of RA patients with gene expression data (n = 31, etanercept-treated). A small, multi-ethnic replication showed a non-significant trend towards an association among etanercept-treated RA patients of Portuguese ancestry (n = 139, P = 0.4), but no association among patients of Japanese ancestry (n = 151, P = 0.8). Our study demonstrates that an allele associated with response to etanercept therapy is also associated with CD84 gene expression, and further that CD84 expression correlates with disease activity. These findings support a model in which CD84 genotypes and/or expression may serve as a useful biomarker for response to etanercept treatment in RA patients of European ancestry. © 2013 Cui et al
High specificity of BCL11B and GLG1 for EWSR1-FLI1 and EWSR1-ERG positive Ewing sarcoma
Ewing sarcoma (EwS) is an aggressive cancer displaying an undifferentiated small-round-cell histomorphology that can be easily confused with a broad spectrum of differential diagnoses. Using comparative transcriptomics and immunohistochemistry (IHC), we previously identified BCL11B and GLG1 as potential specific auxiliary IHC markers for EWSR1-FLI1-positive EwS. Herein, we aimed at validating the specificity of both markers in a far larger and independent cohort of EwS (including EWSR1-ERG-positive cases) and differential diagnoses. Furthermore, we evaluated their intra-tumoral expression heterogeneity. Thus, we stained tissue microarrays from 133 molecularly confirmed EwS cases and 320 samples from morphological mimics, as well as a series of patient-derived xenograft (PDX) models for BCL11B, GLG1, and CD99, and systematically assessed the immunoreactivity and optimal cut-offs for each marker. These analyses demonstrated that high BCL11B and/or GLG1 immunoreactivity in CD99-positive cases had a specificity of 97.5% and an accuracy of 87.4% for diagnosing EwS solely by IHC, and that the markers were expressed by EWSR1-ERG-positive EwS. Only little intra-tumoral heterogeneity in immunoreactivity was observed for differential diagnoses. These results indicate that BCL11B and GLG1 may help as specific auxiliary IHC markers in diagnosing EwS in conjunction with CD99, especially if confirmatory molecular diagnostics are not available
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