Paramagnons and high-temperature superconductivity in a model family of cuprates

Cuprate superconductors have the highest critical temperatures (Tc) at ambient pressure, yet a consensus on the superconducting mechanism remains to be established. Finding an empirical parameter that limits the highest reachable Tc can provide crucial insight into this outstanding problem. Here, in the first two Ruddlesden-Popper members of the model Hg- family of cuprates, which are chemically nearly identical and have the highest Tc among all cuprate families, we use inelastic photon scattering to reveal that the energy of magnetic fluctuations may play such a role. In particular, we observe the single-paramagnon spectra to be nearly identical between the two compounds, apart from an energy scale difference of ~30% which matches their difference in Tc. The empirical correlation between paramagnon energy and maximal Tc is further found to extend to other cuprate families with relatively high Tc’s, hinting at a fundamental connection between them

Povezanost polimorfizma pojedinačnog nukleotida gena ARID4A i kvalitete sperme kineskog vodenog bivola

ARID4A (AT-rich interaction domain 4A) is closely related to animal sperm quality traits. In the present study, the association between ARID4A gene polymorphisms of Chinese water buffalo (Bubalus bubalis) with sperm quality traits was examined, including ejaculate volume, sperm concentration, post-thaw sperm motility, and sperm abnormality of buffalo semen. Seven single-nucleotide polymorphisms (SNPs) of ARID4A gene were detected in 156 Chinese water buffaloes by Sanger sequencing and identifying overlap peaks. Among the SNPs, six were associated with at least one sperm quality trait. In brief, g.21192G>C, g.21285C>G, and g.21364A>G could be used as potential markers for selecting semen with low sperm abnormality, high ejaculate volume, sperm concentration, and sperm motility. Furthermore, 10 haplotypes (H1: -CTCGG, H2: GTGGCA, H3: GCGGCA, H4: GCTGCA, H5: GCTCGA, H6: GTGGGG, H7: GCTCCG, H8: -CGGGA, H9: GCGGCG, and H10: GTTGCA) were formed by the six SNPs through linkage disequilibrium analysis, and then 14 different combined haplotypes were collected. Correlation analysis showed that the combined H1H2 haplotype had the highest genotype frequency. Notably, the combined H1H2 haplotype had low sperm concentration, low sperm motility, and high sperm abnormality. The combined H2H3 haplotype could be used as a potential molecular marker for selecting semen with high sperm motility. In general, we illustrated a significant correlation between SNPs in ARID4A and sperm quality traits of Chinese water buffalo, which may be useful in the marker-assisted selection of buffalo breeding. This study was the first to analyze the genetic polymorphisms of ARID4A and association with sperm qualities of Chinese buffalo.Gen ARID4A (engl AT-rich interaction domain 4A) usko je povezan s kvalitetom sperme. U ovom je radu istraživana povezanost polimorfizma gena ARID4A u kineskih vodenih bivola (Bubalus bubalis) s kvalitetom sperme, uključujući volumen ejakulata, koncentraciju sperme, pokretljivost spermija nakon odmrzavanja i abnormalnost spermija u sjemenu bivola. U 156 kineskih vodenih bivola otkriveno je sedam polimorfizama pojedinačnog nukleotida (SNPs) gena ARID4A Sangerovim sekvenciranjem i identifikacijom preklopljenih vrhova. Među SNP-ovima njih je šest bilo povezano s barem jednim svojstvom kvalitete spermija. Ukratko, g. 21192G>C, g. 21285C>G i g. 21364A>G mogu se upotrijebiti kao potencijalni markeri za selekciju sjemena s niskom abnormalnošću spermija, većim volumenom ejakulata, većom koncentracijom i pokretljivošću spermija. Nadalje, šest SNP-ova formiralo je 10 haplotipova (H1: -CTCGG, H2: GTGGCA, H3: GCGGCA, H4: GCTGCA, H5: GCTCGA, H6: GTGGGG, H7: GCTCCG, H8: -CGGGA, H9: GCGGCG i H10: GTTGCA) analizom povezanosti nepodudarnosti te je ustanovljeno 14 različitih kombiniranih haplotipova. Analiza korelacije pokazala je da kombinirani haplotip H1H2 ima najveću učestalost. Kombinirani haplotip H1H2 imao je najmanju koncentraciju sperme, slabu pokretljivost seprmija i znatnu abnormalnost spermija. Kombinirani haplotip H2H3 može se upotrijebiti kao potencijalni molekularni marker za odabir sjemena s većom pokretljivošću. Općenito je pokazana znakovita korelacija između SNP-ova u ARID4A i kvalitete sperme kineskog vodenog bivola, što može biti korisno u selekciji bivola potpomognutoj markerima. Ovo je prvo istraživanje koje je analiziralo genske polimorfizme ARID4A i njihovu povezanost s kvalitetom sjemena kineskih vodenih bivola

Irradiation resistance of MAX phases Ti3SiC2 and Ti3AlC2: Characterization and comparison

The microstructural evolution and the changes in mechanical properties of 7 MeV Xe26+-ion-irradiated Ti3SiC2 and Ti3AlC2 were investigated. At room temperature (RI), compared with Ti3SiC2, Ti3AlC2 showed a better resistance to irradiation damage, but underwent a more severe phase transition from a phase to beta phase. Rietveld refinement of X-ray diffraction patterns showed that the fraction of beta phase of Ti3SiC2 and Ti3AlC2 samples irradiated at RT to a dose of 2 x 10(15) ions/cm(2) are 28.05% and 57.42%, respectively. At a dose of 4 x 10(15) ions/cm(2), the crystal lattice of Ti3AlC2 was hardly damaged, while the lattice of Ti3SiC2 was heavily distorted. The hardness of Ti3SiC2 and Ti3AlC2 increased after RT irradiation, due to defect pinning effect. Moreover, both MAX phases irradiated at 600 degrees C shoved much better stabilities than after irradiation at RT. (C) 2015 Elsevier B.V. All rights reserved

Design of GSH-Responsive Curcumin Nanomicelles for Oesophageal Cancer Therapy

Oesophageal cancer is a malignant tumor with high morbidity and mortality. Surgical treatment, radiotherapy, and chemotherapy are the most common treatment methods for oesophageal cancer. However, traditional chemotherapy drugs have poor targeting performance and cause serious adverse drug reactions. In this study, a GSH-sensitive material, ATRA-SS-HA, was developed and self-assembled with curcumin, a natural polyphenol antitumor drug, into nanomicelles Cur@ATRA-SS-HA. The micelles had a suitable particle size, excellent drug loading, encapsulation rate, stability, biocompatibility, and stable release behaviour. In the tumor microenvironment, GSH induced disulfide bond rupture in Cur@ATRA-SS-HA and promoted the release of curcumin, improving tumor targeting. Following GSH-induced release, the curcumin IC50 value was significantly lower than that of free curcumin and better than that of 5-FU. In vivo pharmacokinetic experiments showed that the drug-loaded nanomicelles exhibited better metabolic behaviour than free drugs, which greatly increased the blood concentration of curcumin and increased the half-life of the drug. The design of the nanomicelle provides a novel clinical treatment for oesophageal cancer

Paramagnons and high-temperature superconductivity in mercury-based cuprates

We present a comparative study of magnetic excitations in the first two Ruddlesden-Popper members of the Hg-family of high-temperature superconducting cuprates, which are chemically nearly identical and have the highest critical temperature ($T_\mathrm{c}$) among all cuprate families. Our inelastic photon scattering experiments reveal that the two compounds' paramagnon spectra are nearly identical apart from an energy scale factor of $\sim130\%$ that matches the ratio of $T_\mathrm{c}$'s, as expected in magnetic Cooper pairing theories. By relating our observations to other cuprates, we infer that the strength of magnetic interactions determines how high $T_\mathrm{c}$ can reach. Our finding can be viewed as a magnetic analogue of the isotope effect, thus firmly supporting models of magnetically mediated high-temperature superconductivity.Comment: 6 pages, 4 figures, SM available via link in pd