Two-dimensional array of magnetic particles: The role of an interaction cutoff

Based on theoretical results and simulations, in two-dimensional arrangements of a dense dipolar particle system, there are two relevant local dipole arrangements: (1) a ferromagnetic state with dipoles organized in a triangular lattice, and (2) an anti-ferromagnetic state with dipoles organized in a square lattice. In order to accelerate simulation algorithms we search for the possibility of cutting off the interaction potential. Simulations on a dipolar two-line system lead to the observation that the ferromagnetic state is much more sensitive to the interaction cutoff $R$ than the corresponding anti-ferromagnetic state. For $R \gtrsim 8$ (measured in particle diameters) there is no substantial change in the energetical balance of the ferromagnetic and anti-ferromagnetic state and the ferromagnetic state slightly dominates over the anti-ferromagnetic state, while the situation is changed rapidly for lower interaction cutoff values, leading to the disappearance of the ferromagnetic ground state. We studied the effect of bending ferromagnetic and anti-ferromagnetic two-line systems and we observed that the cutoff has a major impact on the energetical balance of the ferromagnetic and anti-ferromagnetic state for $R \lesssim 4$. Based on our results we argue that $R \approx 5$ is a reasonable choice for dipole-dipole interaction cutoff in two-dimensional dipolar hard sphere systems, if one is interested in local ordering.Comment: 8 page

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd

Phenotypes Determined by Cluster Analysis and Their Survival in the Prospective European Scleroderma Trials and Research Cohort of Patients With Systemic Sclerosis

Objective: Systemic sclerosis (SSc) is a heterogeneous connective tissue disease that is typically subdivided into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) depending on the extent of skin involvement. This subclassification may not capture the entire variability of clinical phenotypes. The European Scleroderma Trials and Research (EUSTAR) database includes data on a prospective cohort of SSc patients from 122 European referral centers. This study was undertaken to perform a cluster analysis of EUSTAR data to distinguish and characterize homogeneous phenotypes without any a priori assumptions, and to examine survival among the clusters obtained. / Methods: A total of 11,318 patients were registered in the EUSTAR database, and 6,927 were included in the study. Twenty‐four clinical and serologic variables were used for clustering. / Results: Clustering analyses provided a first delineation of 2 clusters showing moderate stability. In an exploratory attempt, we further characterized 6 homogeneous groups that differed with regard to their clinical features, autoantibody profile, and mortality. Some groups resembled usual dcSSc or lcSSc prototypes, but others exhibited unique features, such as a majority of lcSSc patients with a high rate of visceral damage and antitopoisomerase antibodies. Prognosis varied among groups and the presence of organ damage markedly impacted survival regardless of cutaneous involvement. / Conclusion: Our findings suggest that restricting subsets of SSc patients to only those based on cutaneous involvement may not capture the complete heterogeneity of the disease. Organ damage and antibody profile should be taken into consideration when individuating homogeneous groups of patients with a distinct prognosis

High neutrophil-to-lymphocyte ratio as an early sign of cardiotoxicity in breast cancer patients treated with anthracycline.

BACKGROUND: Cardiotoxicity, defined mainly as left ventricle (LV) dysfunction, is a significant side effect of anthracyclines (ANT) therapy. The need for an early simple marker to identify patients at risk is crucial. A high neutrophil-to-lymphocyte ratio (NLR) has been associated with poor prognosis in cancer patients; however, its role as a predictor for cardiotoxicity development is unknown. OBJECTIVE: Evaluating whether elevated NLR, during ANT exposure, plays a predictive role in the development of cardiotoxicity as defined by LV global longitudinal strain (LV GLS) relative reduction (≥10%). METHODS AND RESULTS: Data were prospectively collected as part of the Israel Cardio-Oncology Registry. A total of 74 female patients with breast cancer, scheduled for ANT therapy were included. NLR levels were assessed at baseline (T1) and during ANT therapy (T2). All patients underwent serial echocardiography at baseline (T1) and after the completion of ANT therapy (T3). NLR ≥ 2.58 at T2 was found to be the optimal predictive cutoff for LV GLS deterioration. A relative LV GLS reduction ≥10% was significantly more common among patients with high NLR (50% vs. 20%, p = .009). NLR ≥ 2.58 at T2 increases the risk for LV GLS reduction by fourfold (odds ratio [OR]: 4.63, 95% confidence interval [CI]: 1.29-16.5, p = .02), with each increase of 1-point NLR adding an additional 15% risk (OR: 1.15, 95% CI: 1.01-1.32, p = .046). CONCLUSIONS: Our study provides novel data that high NLR levels, during ANT exposure, have an independent association with the development of LV dysfunction. Routine surveillance of NLR may be an effective means of risk-stratifying