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Unmovable nodal points (UNPs) and lines (UNLs) are band crossings whose positions in the Brillouin zone are unaltered by symmetry preserving perturbations. Not only positions but also the band structure in their vicinity are determined by the little group of wave vectors and its irreducible (co)representations. In this paper, we give the full set of electronic dispersions near all UNPs and UNLs in non-magnetic quasi two-dimensional (2D) materials, both with and without spin–orbit coupling (SOC). Analysis of all layer gray single and double groups gives nineteen different quasiparticles, the great majority of which are unavoidable for a 2D material that belongs to a certain layer group. This includes Weyl and Dirac nodal lines, dispersions with quadratic or cubic splitting, anisotropic Weyl and Dirac cones, whose orientation can be varied by e.g. strain etc. We indicated quasiparticles that are robust to SOC. For convenience, our results are concisely presented graphically—as a map, not in a tabular, encyclopedia form. They may be of use as checkpoints and/or for fitting experimentally (via e.g. ARPES) and numerically obtained electronic band structures data, as well as for deeper theoretical investigations. [ABSTRACT FROM AUTHOR]

One of the more important developments in magnetic materials, polymer bonded magnets, have opened a new world of application opportunities. The Nd–Fe–B/polymer composite materials offer an excellent combination of strong magnetic and dynamical-mechanical properties. However, the transition temperatures of filler and matrix should be selected carefully considering the future application. Uniform particle distribution and good adhesion between Nd–Fe–B powder particles and polymer are essential for the quality of the composite, while stiffness of polymer matrix is one of the influencing factors as well. The damping properties of Nd–Fe–B/polymer composites with 15 wt.%, 50 wt.% and 75 wt.% of Nd–Fe–B powder were studied by dynamic mechanical analysis and compared with a pure polymer sample. Thermal stability was analyzed using a simultaneous differential scanning calorimetric and thermogravimetric analysis technique. [ABSTRACT FROM AUTHOR]

Considered are 80 sets of layer groups, each set consisting of four groups: ordinary single and double, and grey single and double layer groups. The structural properties of layer groups (factorization into cyclic subgroups and the existence of grading according to the sequence of halving subgroups) enable efficient symbolic computation (by the POLSym code) of the relevant properties, real and complex irreducible and allowed (half-)integer (co-)representations in particular. This task includes, as the first step, classification of the irreducible domains based on the group action in the Brillouin zone combined with torus topology. Also, the band (co-)representations induced from the irreducible (co-)representations of Wyckoff-position stabilizers (site-symmetry groups) are decomposed into the irreducible components. These, and other layer group symmetry related theoretical data relevant for physics, layered materials in particular, are tabulated and made available through the web site https://nanolab.group/layer/.

Metabolic syndrome (MetS) is a combination of cardiovascular risk factors associated with type 2 diabetes, obesity, and cardiovascular diseases. The circadian clock gene polymorphisms are very likely to participate in metabolic syndrome genesis and development. However, research findings of the association between circadian rhythm gene polymorphisms and MetS and its comorbidities are not consistent. In this study, a review of the association of circadian clock gene polymorphisms with overall MetS risk was performed. In addition, a meta-analysis was performed to clarify the association between circadian clock gene polymorphisms and MetS susceptibility based on available data. The PubMed and Scopus databases were searched for studies reporting the association between circadian rhythm gene polymorphisms (ARNTL, BMAL1, CLOCK, CRY, PER, NPAS2, REV-ERBα, REV-ERBβ, and RORα) and MetS, and its comorbidities diabetes, obesity, and hypertension. Thirteen independent studies were analyzed with 17,381 subjects in total. The results revealed that the BMAL1 rs7950226 polymorphism was associated with an increased risk of MetS in the overall population. In contrast, the CLOCK rs1801260 and rs6850524 polymorphisms were not associated with MetS. This study suggests that some circadian rhythm gene polymorphisms might be associated with MetS in different populations and potentially used as predictive biomarkers for MetS.

Symmetry indicates that low energy spectra of materials could be richer than well-known Dirac, semi-Dirac, or quadratic, hosting some unusual quasiparticles. Performing the systematic study of exact forms of low energy effective Hamiltonians and dispersions in high-symmetry points with fourfold degeneracy of bands, we found new, previously unreported dispersion, which we named poppy flower (PF) after its shape. This massless fermion exists in non-magnetic two-dimensional (2D) crystals with spin-orbit coupling (SOC), which are invariant under one of the proposed ten noncentrosymmetric layer groups. We suggest real three-dimensional (3D) layered materials suitable for exfoliation, having layers that belong to these symmetry groups as candidates for realization of PF fermions. In 2D systems without spin-orbit interaction, fortune teller (FT)-like fermions were theoretically predicted, and afterward experimentally verified in the electronic structure of surface layer of silicon. Herein, we show that such fermions can also be hosted in 2D crystals with SOC, invariant under additional two noncentrosymmetric layer groups. This prediction is confirmed by density functional based calculation: layered BiIO 4 , which has been synthesized already as a 3D crystal, exfoliates to stable monolayer with symmetry pb 2 1 a , and FT fermion is observed in the band structure. Analytically calculated density of states (DOS) of the PF shows semimetallic characteristic, in contrast to metallic nature of FT having non-zero DOS at the bands contact energy. We indicate possibilities for symmetry breaking patterns which correspond to the robustness of the proposed dispersions as well as to the transition from Dirac centrosymmetric semimetal to PF., (© 2020 IOP Publishing Ltd.)

Spin line groups describe the symmetries of spin arrangements in quasi-one-dimensional systems. These groups are derived for the first family of line groups. Among them, magnetic groups are singled out as a special case. Spin arrangements generated by the derived groups are first discussed for single-orbit systems and then the conclusions are extended to multi-orbit cases. The results are illustrated by the examples of a CuO2 zigzag chain, a (13)C nanotube and the hexaferrite Ba2Mg2Fe12O22. Applications to neutron diffraction and classical ground-state determination are indicated.

The aim of this study was to investigate in what way the outcome of treatment could be influenced by some traits of personality and its functioning, described in psychological literature as "ego strength". Here, one has to take into account the difficulties in studying the complex process of treatment involving numerous personality and environmental factors, which cannot be separated and observed, measured and assessed as isolated values. Therefore, conclusions about the influence of personality strength on the outcome of treatment have a relevant but not absolute significance. The authors presumed that one of the reasons for the unfavourable outcome of treatment was to be found in the alcoholic's personality system. They tested this presumption on samples of successfully and unsuccessfully treated alcoholics, who received the same treatment, and on a control group. As a measuring instrument for assessing the effectiveness of the personality system, Barron's Ego Strength Scale was used. The study showed that the group of unsuccessfully treated alcoholics had statistically significant lower scores on the ES scale, and that they differed from the successfully treated group. Between successfully treated alcoholics and the control group there were no statistically significant ES Scale differences. The study has indicated that it would be appropriate to use ES Scale before beginning the treatment of alcoholics. Thus in the treatment of those with lower scores, additional attention and activities could be devoted to other systems, those of family and work, within the general system of "man-environment", in order to compensate for the relative inadequacy of the personality system.

The Teffect of haemodialysis on the level of TBG and thyroid hormones in the serum of patients, suffering from terminal form of kidney insufficiency, were investigated. It was established that in the majority of patients euthyroid function of the thyroid gland was preserved. According to our results this preservation of euthyroid function results from the decreased concentration of sera TBG, which follows the decrease of total sera proteins as well as increased peripheral conversion of thyroxine mostly in rT3.