71 research outputs found
Magnetization Plateau of Classical Ising Model on Shastry-Sutherland Lattice
We study the magnetization for the classical antiferromagnetic Ising model on
the Shastry-Sutherland lattice using the tensor renormalization group approach.
With this method, one can probe large spin systems with little finite-size
effect. For a range of temperature and coupling constant, a single
magnetization plateau at one third of the saturation value is found. We
investigate the dependence of the plateau width on temperature and on the
strength of magnetic frustration. Furthermore, the spin configuration of the
plateau state at zero temperature is determined.Comment: 6 pages, 8 figure
Magnetic structure and phase diagram of TmB4
Magnetic structure of single crystalline TmB4 has been studied by
magnetization, magnetoresistivity and specific heat measurements. A complex
phase diagram with different antiferromagnetic (AF) phases was observed below
TN1 = 11.7 K. Besides the plateau at half-saturated magnetization (1/2 MS),
also plateaus at 1/9, 1/8 and 1/7 of MS were observed as function of applied
magnetic field B//c. From additional neutron scattering experiments on TmB4, we
suppose that those plateaus arise from a stripe structure which appears to be
coherent domain boundaries between AF ordered blocks of 7 or 9 lattice
constants. The received results suggest that the frustration among the Tm3+
magnetic ions, which maps to a geometrically frustrated Shastry-Sutherland
lattice lead to strong competition between AF and ferromagnetic (FM) order.
Thus, stripe structures in intermediate field appear to be the best way to
minimize the magnetostatic energy against other magnetic interactions between
the Tm ions combined with very strong Ising anisotropy.Comment: 4 pages, 4 figures, conference contribution - CSMAG 0
Coronary Microvascular Angina: A State-of-the-Art Review
Up to 60-70% of patients, undergoing invasive coronary angiography due to angina and demonstrable myocardial ischemia with provocative tests, do not have any obstructive coronary disease. Coronary microvascular angina due to a dysfunction of the coronary microcirculation is the underlying cause in almost 50% of these patients, associated with a bad prognosis and poor quality of life. In recent years, progress has been made in the diagnosis and management of this condition. The aim of this review is to provide an insight into current knowledge of this condition, from current diagnostic methods to the latest treatments.Copyright © 2022 Spione, Arevalos, Gabani, Sabaté and Brugaletta
Searching for a quantum critical point in YbCu5-xAux
Structural, magnetic, transport and thermal properties of YbCu5-xAux alloys
with Au concentration between the limit of structural stability of AuBe5 type
at x = 0.4 up to x = 0.7 are reported. The outstanding features of this system
are: i) the constant and record high values of Cm /T 7J/molK^2 below a
characteristic temperature T*, ranging between 150 mK and 350 mK. ii) A power
law thermal dependence dependence Cm/T(T>T*)=A/T^q, with q = 1.3 +/- 0.1, and
iii) an arising incoherent electronic scattering observed in the resistivity at
T < 1K for x < 0.6 despite the fact that Yb magnetic atoms are placed in a
lattice. Magnetic frustration, originated in the tetrahedral distribution of Yb
atoms, appears as the responsible of the exotic behavior of this system.Comment: 14 pages, 9 figure
Sirtuin1 protects endothelial Caveolin-1 expression and preserves endothelial function via suppressing miR-204 and endoplasmic reticulum stress.
Sirtuin1 (Sirt1) is a class III histone deacetylase that regulates a variety of physiological processes, including endothelial function. Caveolin1 (Cav1) is also an important determinant of endothelial function. We asked if Sirt1 governs endothelial Cav1 and endothelial function by regulating miR-204 expression and endoplasmic reticulum (ER) stress. Knockdown of Sirt1 in endothelial cells, and in vivo deletion of endothelial Sirt1, induced endothelial ER stress and miR-204 expression, reduced Cav1, and impaired endothelium-dependent vasorelaxation. All of these effects were reversed by a miR-204 inhibitor (miR-204 I) or with overexpression of Cav1. A miR-204 mimic (miR-204 M) decreased Cav1 in endothelial cells. In addition, high-fat diet (HFD) feeding induced vascular miR-204 and reduced endothelial Cav1. MiR-204-I protected against HFD-induced downregulation of endothelial Cav1. Moreover, pharmacologic induction of ER stress with tunicamycin downregulated endothelial Cav1 and impaired endothelium-dependent vasorelaxation that was rescued by overexpressing Cav1. In conclusion, Sirt1 preserves Cav1-dependent endothelial function by mitigating miR-204-mediated vascular ER stress
Oncology trainee perceptions of the prior authorization process: A national survey
Purpose: The medical trainee perspective regarding the prior authorization process has not been previously assessed. Here we evaluate the perceptions of radiation and medical oncology trainees regarding the prior authorization process and its effect on their training and patient care.
Methods and Materials: A 12-question, nonincentivized, electronic national survey of radiation and medical oncology trainees at all Accreditation Council for Graduate Medical Education accredited oncology programs was conducted. Participation, perspectives, and experiences with the prior authorization process were assessed by Likert scale, free response, and multiple response selection.
Results: Between January and March of 2019, the survey was distributed to 1505 trainees at 76 institutions with responses from 174/616 radiation (28.2%) and 139/889 medical oncology trainees (15.6%). The majority (69.2%) reported participating in the prior authorization process (radiation: 78.2% vs medical: 57.6%;
Conclusions: These data indicate that trainees in US oncology programs are active participants in the prior authorization process and report that prior authorization approvals negatively influence their medical training and the quality of patient care. Additional efforts to revise the insurance approval process are warranted
Large, high quality single-crystals of the new Topological Kondo Insulator, SmB6
SmB6 has recently been predicted to be a Topological Kondo Insulator, the first strongly correlated heavy fermion material to exhibit topological surface states. High quality crystals are necessary to investigate the topological properties of this material. Single crystal growth of the rare earth hexaboride, SmB6, has been carried out by the floating zone technique using a high power xenon arc lamp image furnace. Large, high quality single-crystals are obtained by this technique. The crystals produced by the floating zone technique are free of contamination from flux materials and have been characterised by resistivity and magnetisation measurements. These crystals are ideally suited for the investigation of both the surface and bulk properties of SmB6
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