A Monte Carlo study of the Falicov–Kimball model in the perturbative regime

Finite-temperature properties of the Falicov–Kimball model on the square lattice have been studied in the perturbative regime, i.e. for t/U << 1, where t is the hopping constant and U denotes the Coulomb interaction strength. In our study, we have determined the phase diagram of the model in the second-order of the perturbation theory, where the antiferromagnetic Ising model in the magnetic field emerges. In the fourth-order, where our model constitutes the Ising model with more complicated frustrated antiferromagnetic interactions, the sketch of the phase diagram was established. The Monte Carlo method was employed and the behavior of Binder cumulants based on the order parameters was analyzed to determine the type of ordering and phase boundaries in the diagram

Platelet Carbonic Anhydrase II, a Forgotten Enzyme, May Be Responsible for Aspirin Resistance

Background. Thromboembolic events constitute a major health problem, despite the steadily expanding arsenal of antiplatelet drugs. Hence, there is still a need to optimize the antiplatelet therapy. Objectives. The aim of our study was to verify a hypothesis that there are no differences in platelet proteome between two groups of healthy people representing different acetylsalicylic acid (aspirin) responses as assessed by the liquid chromatography/mass spectrometry (LC/MS) technique. Patients/Methods. A total of 61 healthy volunteers were recruited for the study. Physical examination and blood collection were followed by platelet-rich plasma aggregation assays and platelet separation for proteomic LC/MS analysis. Arachidonic acid- (AA-) induced aggregation (in the presence of aspirin) allowed to divide study participants into two groups aspirin-resistant (AR) and aspirin-sensitive (AS) ones. Subsequently, platelet proteome was compared in groups using the LC/MS analysis. Results. The LC/MS analysis of platelet proteome between groups revealed that out of all identified proteins, the only discriminatory protein, affecting aspirin responsiveness, is platelet carbonic anhydrase II (CA II). Conclusions. CA II is a platelet function modulator and should be taken into consideration as a cardiovascular event risk factor or therapeutic target

Contemporary management of Patent Foramen Ovale: A multinational survey on cardiologists' perspective

Objectives. The purpose of our survey is to analyze the clinical approach used by interventional and imaging cardiologists to diagnose, treat, and follow-up patients with PFO-related left circulation thromboembolism in different parts of the world with particular emphasis on adherence to current guidelines. Background. Firm guidelines do not cover many aspects of PFO-related patient care. Consequently, very disparate approaches exist among clinicians in the real-world. Methods. A 24-item electronic questionnaire was sent directly to experienced cardiology specialists practicing at consultant/attending positions directly involved in PFO closure management in the United States, United Kingdom, Gulf countries, and other countries. There were no unanswered questions. Responses were recorded between October 2019 and July 2020. Results. Seventy-one responses were obtained: 31 from the UK, 19 from the US, 16 from Gulf countries, 2 from Poland, and 1 response from Australia, Italy, and Switzerland. The overall response rate was 76%. Significant differences between regions were noted in the duration of ECG monitoring during the diagnostic process, PFO closure for left circulation thromboembolism other than stroke/transient ischemic attack, and intraoperative use of intracardiac echocardiography. A similar pattern was noted in the lack of routine screening for thrombophilia and the use of the long-term single antiplatelet therapy. Conclusions. The study shows a vast spectrum of opinions on the optimal approach to PFO closure with significant differences between the US, UK, and Gulf countries. The results stress the need for systematic, high-quality data on the diagnostic work-up and follow-up strategies to inform the standardized approach

Etiology matters - genomic DNA methylation patterns in three rat models of acquired epilepsy

This study tested the hypothesis that acquired epileptogenesis is accompanied by DNA methylation changes independent of etiology. We investigated DNA methylation and gene expression in the hippocampal CA3/dentate gyrus fields at 3 months following epileptogenic injury in three experimental models of epilepsy: focal amygdala stimulation, systemic pilocarpine injection, or lateral fluid-percussion induced traumatic brain injury (TBI) in rats. In the models studies, DNA methylation and gene expression profiles distinguished controls from injured animals. We observed consistent increased methylation in gene bodies and hypomethylation at non-genic regions. We did not find a common methylation signature in all three different models and few regions common to any two models. Our data provide evidence that genome-wide alteration of DNA methylation signatures is a general pathomechanism associated with epileptogenesis and epilepsy in experimental animal models, but the broad pathophysiological differences between models (i.e. pilocarpine, amygdala stimulation, and post-TBI) are reflected in distinct etiology-dependent DNA methylation patterns

Survey of period variations of superhumps in SU UMa-type dwarf novae. VI. The sixth year (2013-2014)

© The Author 2014. Published by Oxford University Press on behalf of the Astronomical Society of Japan. All rights reserved. Continuing the project undertaken by Kato et al. (2009), we collected times of superhump maxima for 56 SU UMa-type dwarf novae mainly observed during the 2013-2014 season and characterized these objects. We detected negative superhumps in VW Hyi and indicated that the low number of normal outbursts in some supercycles can be interpreted as a result of disk tilt. This finding, combined with the Kepler observation of V1504 Cyg and V344 Lyr, suggests that disk tilt is responsible for modulating the outburst pattern in SU UMa-type dwarf novae. We also studied the deeply eclipsing WZ Sge-type dwarf nova MASTER OT J005740.99+443101.5 and found evidence of a sharp eclipse during the phase of early superhumps. The profile can be reproduced by a combination of the eclipse of the axisymmetric disk and the uneclipsed light source of early superhumps. This finding shows the lack of evidence for a greatly enhanced hot spot during the early stage of WZ Sge-type outburst. We detected growing (stage A) superhumps in MN Dra and give a suggestion that some of SU UMa-type dwarf novae situated near the critical condition of tidal instability may show long-lasting stage A superhumps. The large negative period derivatives reported in such systems can be understood as a result of the combination of stage A and B superhumps. Two WZ Sge-type dwarf novae, AL Com and ASASSN-13ck, showed a long-lasting (plateau-type) rebrightening. In the early phase of their rebrightenings, both objects showed a precursor-like outburst, suggesting that the long-lasting rebrightening is triggered by a precursor outburst

Thermally coupled FEM analysis of diesel engine components

Praca zawiera wyniki analizy numerycznej w ujęciu metody elementów skończonych rozkładów naprężeń, temperatur oraz odkształceń w elementach silnika diesla ZS. Zakres obliczeń obejmował sprzężoną analizę temperaturowoprzemieszczeniową elementów konstrukcji z uwzględnieniem zagadnień geometrycznie nieliniowych oraz liniowosprężystych własnościach materiałowych. Istotne znaczenie w procesie prowadzonych obliczeń miało zastosowanie analizy sprzężonej, umożliwiającej jednoczesne uwzględnienie zagadnień termicznych oraz wynikających z nich efektów naprężeniowych. Takie podejście umożliwia prowadzenie kompleksowej analizy konstrukcji obciążonych cieplnie, jednakże wiąże się to z koniecznością zastosowania specjalnych typów elementów skończonych, posiadających dodatkowy stopień swobody pozwalający na uwzględnienie zagadnień termicznych.The paper contains results of numerical analysis of stress, temperature and deformation distributions in diesel engine components, performed by means of MES. The scope of calculations include thermally coupled analysis of structural components, in which linear elastic properties and geometrically nonlinear problems were taken into account. The application of thermally coupled analysis, which enabled to consider simultaneously thermal fields and related deformation distributions, had a significant effect on the results obtained. Such approach enables to carry out a complex analysis of thermally loaded structures and requires application of special type elements with an additional degree of freedom to take thermal problems into consideration

Conditions which ensure that a simple map does not raise dimension

The present paper deals with those continuous maps from compacta into metric spaces which assume each value at most twice. Such maps are called here, after Borsuk and Molski (1958) and as in our previous paper (1990), simple. We investigate the possibility of decomposing a simple map into essential and elementary factors, and the so-called splitting property of simple maps which raise dimension. The aim is to get insight into the structure of those compacta which have the property that simple maps from them do not raise dimension. In what follows a map means a continuous map, unless explicitly stated otherwise. A space is, except in some general lemmas, understood to be metrizable. A compactum means a compact metric space