The Lifshitz transition, a change in Fermi surface topology, is likely to greatly influence exotic correlated phenomena in solids, such as high-temperature superconductivity and complex magnetism. ...However, since the observation of Fermi surfaces is generally difficult in the strongly correlated systems, a direct link between the Lifshitz transition and quantum phenomena has been elusive so far. Here, we report a marked impact of the pressure-induced Lifshitz transition on thermoelectric performance for SnSe, a promising thermoelectric material without a strong electron correlation. By applying pressure up to 1.6 GPa, we have observed a large enhancement of the thermoelectric power factor by more than 100% over a wide temperature range (10-300 K). Furthermore, the high carrier mobility enables the detection of quantum oscillations of resistivity, revealing the emergence of new Fermi pockets at ∼0.86 GPa. The observed thermoelectric properties linked to the multivalley band structure are quantitatively reproduced by first-principles calculations, providing novel insight into designing the SnSe-related materials for potential valleytronic as well as thermoelectric applications.
Many exotic compounds, such as cuprate superconductors and heavy fermion materials, exhibit a linear in temperature (T) resistivity, the origin of which is not well understood. We found that the ...resistivity of the quantum critical metal Sr(3)Ru(2)O(7) is also T-linear at the critical magnetic field of 7.9 T. Using the precise existing data for the Fermi surface topography and quasiparticle velocities of Sr(3)Ru(2)O(7), we show that in the region of the T-linear resistivity, the scattering rate per kelvin is well approximated by the ratio of the Boltzmann constant to the Planck constant divided by 2π. Extending the analysis to a number of other materials reveals similar results in the T-linear region, in spite of large differences in the microscopic origins of the scattering.
Abstract
Genebanks provide access to diverse materials for crop improvement. To utilize and evaluate them effectively, core collections, such as the World Rice Core Collection (WRC) in the Genebank ...at the National Agriculture and Food Research Organization, have been developed. Because the WRC consists of 69 accessions with a high degree of genetic diversity, it has been used for >300 projects. To allow deeper investigation of existing WRC data and to further promote research using Genebank rice accessions, we performed whole-genome resequencing of these 69 accessions, examining their sequence variation by mapping against the Oryza sativa ssp. japonica Nipponbare genome. We obtained a total of 2,805,329 single nucleotide polymorphisms (SNPs) and 357,639 insertion–deletions. Based on the principal component analysis and population structure analysis of these data, the WRC can be classified into three major groups. We applied TASUKE, a multiple genome browser to visualize the different WRC genome sequences, and classified haplotype groups of genes affecting seed characteristics and heading date. TASUKE thus provides access to WRC genotypes as a tool for reverse genetics. We examined the suitability of the compact WRC population for genome-wide association studies (GWASs). Heading date, affected by a large number of quantitative trait loci (QTLs), was not associated with known genes, but several seed-related phenotypes were associated with known genes. Thus, for QTLs of strong effect, the compact WRC performed well in GWAS. This information enables us to understand genetic diversity in 37,000 rice accessions maintained in the Genebank and to find genes associated with different phenotypes.
The sequence data have been deposited in DNA Data Bank of Japan Sequence Read Archive (DRA) (Supplementary Table S1).
Topologically nontrivial materials host protected edge states associated with the bulk band inversion through the bulk-edge correspondence. Manipulating such edge states is highly desired for ...developing new functions and devices practically using their dissipation-less nature and spin-momentum locking. Here we introduce a transition-metal dichalcogenide VTe
, that hosts a charge density wave (CDW) coupled with the band inversion involving V3d and Te5p orbitals. Spin- and angle-resolved photoemission spectroscopy with first-principles calculations reveal the huge anisotropic modification of the bulk electronic structure by the CDW formation, accompanying the selective disappearance of Dirac-type spin-polarized topological surface states that exist in the normal state. Thorough three dimensional investigation of bulk states indicates that the corresponding band inversion at the Brillouin zone boundary dissolves upon the CDW formation, by transforming into anomalous flat bands. Our finding provides a new insight to the topological manipulation of matters by utilizing CDWs' flexible characters to external stimuli.
•New strength design and evaluation rules were developed for railway axles.•Fatigue damage was evaluated by variations in the in-service conditions.•Safety assessment involved comparing equivalent ...stress with past proven values.•Full-scale fatigue tests of railway axles were performed to clarify the S–N curve.•Inverse values of S–N curve slope were specified for different axle types and parts.
Fatigue-limit-based designs were employed for railway axles in Japan, and new strength design and evaluation rules were developed to achieve more reasonable designs. Design specifications for strength were introduced to describe the detailed processes, whereas other specifications were introduced to propose a method for the estimation of the fatigue damage caused by variations in in-service conditions. Further, safety assessments were implemented by comparing the equivalent stress with the reference values obtained from past safe-operation records. The proposed assessment method is superior to previously used techniques for railway axles because of its low safety risk. To clarify the S–N curve of axles, full-scale fatigue tests were performed on railway axles used in Japan. The slopes of the S–N curve were specified in the damage evaluation rules.
RNF213 was recently reported as a susceptibility gene for moyamoya disease (MMD). Our aim was to clarify the correlation between the RNF213 genotype and MMD phenotype.
The entire coding region of the ...RNF213 gene was sequenced in 204 patients with MMD, and corresponding variants were checked in 62 pairs of parents, 13 mothers and 4 fathers of the patients, and 283 normal controls. Clinical information was collected. Genotype-phenotype correlations were statistically analyzed.
The c.14576G>A variant was identified in 95.1% of patients with familial MMD, 79.2% of patients with sporadic MMD, and 1.8% of controls, thus confirming its association with MMD, with an odds ratio of 259 and p < 0.001 for either heterozygotes or homozygotes. Homozygous c.14576G>A was observed in 15 patients but not in the controls and unaffected parents. The incidence rate for homozygotes was calculated to be >78%. Homozygotes had a significantly earlier age at onset compared with heterozygotes or wild types (median age at onset 3, 7, and 8 years, respectively). Of homozygotes, 60% were diagnosed with MMD before age 4, and all had infarctions as the first symptom. Infarctions at initial presentation and involvement of posterior cerebral arteries, both known as poor prognostic factors for MMD, were of significantly higher frequency in homozygotes than in heterozygotes and wild types. Variants other than c.14576G>A were not associated with clinical phenotypes.
The homozygous c.14576G>A variant in RNF213 could be a good DNA biomarker for predicting the severe type of MMD, for which early medical/surgical intervention is recommended, and may provide a better monitoring and prevention strategy.
Abstract
The heavy fermion paramagnet UTe
2
exhibits numerous characteristics of spin-triplet superconductivity. Efforts to understand the microscopic details of this exotic superconductivity have ...been impeded by uncertainty regarding the underlying electronic structure. Here we directly probe the Fermi surface of UTe
2
by measuring magnetic quantum oscillations in pristine quality crystals. We find an angular profile of quantum oscillatory frequency and amplitude that is characteristic of a quasi-2D Fermi surface, which we find is well described by two cylindrical Fermi sheets of electron- and hole-type respectively. Additionally, we find that both cylindrical Fermi sheets possess considerable undulation but negligible small-scale corrugation, which may allow for their near-nesting and therefore promote magnetic fluctuations that enhance the triplet pairing mechanism. Importantly, we find no evidence for the presence of any 3D Fermi surface sections. Our results place strong constraints on the possible symmetry of the superconducting order parameter in UTe
2
.
Canine haemangiosarcoma (HSA), like human angiosarcoma, is an uncommon malignant vascular endothelial cell tumour associated with a poor prognosis. The peroxiredoxin (PRDX) family of peroxidases, ...which comprises six members in mammals (PRDX1–6), might contribute to cancer cell survival in the face of oxidative stress as these proteins exhibit frequent upregulation in cancer cells. In this study, we investigated the expression levels of PRDX6 in spontaneously arising primary canine HSAs by immunohistochemical analysis, identifying marked expression of this protein. Both PRDX6 mRNA and protein were overexpressed in HSA cell lines compared with normal canine endothelial cells, although some variation was observed between the different HSA cell lines. Small interfering RNA-induced downregulation of PRDX6 promoted apoptosis in the HSA cell lines. The observation that PRDX6 suppression increased the cytotoxicity of these cells suggests that PRDX6 might play an important cytoprotective role.
Platinum-based two-drug combination chemotherapy has been standard of care for patients with advanced nonsmall-cell lung cancer (NSCLC). The primary aim was to compare overall survival (OS) of ...patients with advanced NSCLC between the two chemotherapy regimens. Secondary end points included progression-free survival (PFS), response, safety, and quality of life (QoL).
Patients with previously untreated stage IIIB or IV NSCLC, an Eastern Cooperative Oncology Group performance status of 0–1 and adequate organ function were randomized to receive either oral S-1 80 mg/m2/day on days 1–21 plus cisplatin 60 mg/m2 on day 8 every 4–5 weeks, or docetaxel 60 mg/m2 on day 1 plus cisplatin 80 mg/m2 on day 1 every 3–4 weeks, both up to six cycles.
A total of 608 patients from 66 sites in Japan were randomized to S-1 plus cisplatin (n = 303) or docetaxel plus cisplatin (n = 305). OS for oral S-1 plus cisplatin was noninferior to docetaxel plus cisplatin median survival, 16.1 versus 17.1 months, respectively; hazard ratio = 1.013; 96.4% confidence interval (CI) 0.837–1.227. Significantly higher febrile neutropenia (7.4% versus 1.0%), grade 3/4 neutropenia (73.4% versus 22.9%), grade 3/4 infection (14.5% versus 5.3%), and grade 1/2 alopecia (59.3% versus 12.3%) were observed in the docetaxel plus cisplatin than in the S-1 plus cisplatin. There were no differences found in PFS or response between the two arms. QoL data investigated by EORTC QLQ-C30 and LC-13 favored the S-1 plus cisplatin.
Oral S-1 plus cisplatin is not inferior to docetaxel plus cisplatin and is better tolerated in Japanese patients with advanced NSCLC.
UMIN000000608.
PDF
