Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

We theoretically analyze possible multiple conformations of protein molecules immobilized by 1-pyrenebutanoic acid succinimidyl ester (PASE) linkers on graphene. The activation barrier between two bi-stable conformations exhibited by PASE is confirmed to be based on the steric hindrance effect between a hydrogen on the pyrene group and a hydrogen on the alkyl group of this molecule. Even after the protein is supplemented, this steric hindrance effect remains if the local structure of the linker consisting of an alkyl group and a pyrene group is maintained. Therefore, it is likely that the kinetic behavior of a protein immobilized with a single PASE linker exhibits an activation barrier-type energy surface between the bi-stable conformations on graphene. We discuss the expected protein sensors when this type of energy surface appears and provide a guideline for improving the sensitivity, especially as an oscillator-type biosensor.

Optimizing Superconductivity: From Cuprates via Nickelates to Palladates

Motivated by cuprate and nickelate superconductors, we perform a comprehensive study of the superconducting instability in the single-band Hubbard model. We calculate the spectrum and superconducting transition temperature T_{c} as a function of filling and Coulomb interaction for a range of hopping parameters, using the dynamical vertex approximation. We find the sweet spot for high T_{c} to be at intermediate coupling, moderate Fermi surface warping, and low hole doping. Combining these results with first principles calculations, neither nickelates nor cuprates are close to this optimum within the single-band description. Instead, we identify some palladates, notably RbSr_{2}PdO_{3} and A_{2}^{'}PdO_{2}Cl_{2} (A^{'}=Ba_{0.5}La_{0.5}), to be virtually optimal, while others, such as NdPdO_{2}, are too weakly correlated.

Nematicity-enhanced superconductivity in systems with a non-Fermi liquid behavior

We explore the interplay between nematicity (spontaneous breaking of the sixfold rotational symmetry), superconductivity, and non-Fermi liquid behavior in partially flat-band (PFB) models on the triangular lattice. A key result is that the nematicity (Pomeranchuk instability), which is driven by many-body effect and stronger in flat-band systems, enhances superconducting transition temperature in a systematic manner on theT_cdome. There, a plausiblesx2+y2-dx2-y2-dxy-wave symmetry, in place of the conventionaldx2-y2-wave, governs the nematicity-enhanced pairing with a sharp rise in theT_cdome on the filling axis. When the sixfold symmetry is spontaneously broken, the pairing interaction is shown to become stronger with more compact pairs in real space than when the symmetry is enforced. These are accompanied by a non-Fermi character of electrons in the PFBs with many-body interactions.

Anomalous transport due to Weyl fermions in the chiral antiferromagnets Mn3X, X = Sn, Ge

The recent discoveries of strikingly large zero-field Hall and Nernst effects in antiferromagnets Mn₃X (X = Sn, Ge) have brought the study of magnetic topological states to the forefront of condensed matter research and technological innovation. These effects are considered fingerprints of Weyl nodes residing near the Fermi energy, promoting Mn₃X (X = Sn, Ge) as a fascinating platform to explore the elusive magnetic Weyl fermions. In this review, we provide recent updates on the insights drawn from experimental and theoretical studies of Mn₃X (X = Sn, Ge) by combining previous reports with our new, comprehensive set of transport measurements of high-quality Mn₃Sn and Mn₃Ge single crystals. In particular, we report magnetotransport signatures specific to chiral anomalies in Mn₃Ge and planar Hall effect in Mn₃Sn, which have not yet been found in earlier studies. The results summarized here indicate the essential role of magnetic Weyl fermions in producing the large transverse responses in the absence of magnetization.

The large anomalous Hall (AHE) and anomalous Nernst effects (ANE) in antiferromagnets Mn₃Sn/Mn₃Ge are considered fingerprints of Weyl nodes residing near the Fermi energy. Here, the authors review the results from previous studies combining with new transport measurements on Mn₃Sn/Mn₃Ge single crystals, suggesting the essential role of magnetic Weyl fermions in explaining the AHE and ANE.

Quantum Criticality in the Two-Dimensional Periodic Anderson Model

We study the phase diagram and quantum critical region of one of the fundamental models for electronic correlations: the periodic Anderson model. Employing the recently developed dynamical vertex approximation, we find a phase transition between a zero-temperature antiferromagnetic insulator and a Kondo insulator. In the quantum critical region, we determine a critical exponent γ=2 for the antiferromagnetic susceptibility. At higher temperatures, we have free spins with γ=1 instead, whereas at lower temperatures, there is an even stronger increase and suppression of the susceptibility below and above the quantum critical point, respectively.

[Arteriosclerosis obliterans]

Arteriosclerosis obliterans (ASO) has become one of major health problems in the elderly people in Japan. This paper reviews the recent progress in the diagnosis and treatment of ASO. Both medical and surgical treatments, such as atherectomy catheters, endovascular metallic stenting, laser angioplasty and LDL-apheresis have recently been greatly developed. As atherosclerosis is a generalised disease, patients with ASO tend to have other atherosclerotic diseases, i.e., cerebrovascular disease, coronary heart disease and renal vascular disease. For the selection of treatments, we have to consider the whole background of the patients, including a quality of life.

A case of ring chromosome 15 accompanied by almost normal intelligence

A further case of ring chromosome 15 in a 12-year-old boy with growth failure is described. He had minor congenital anomalies, but almost normal intelligence.

Localization of the spherocytosis gene to chromosome segment 8p11.22----8p21

A case of hereditary spherocytosis (HS) is reported. Cytogenetic study revealed a de novo minute deletion of chromosome 8. The critical portion which affected the expression of the HS phenotype appeared to be localized to 8p11.22----8p21.1.