Signature of hidden order and evidence for periodicity modification in URu₂Si₂

The detail of electronic structures near the Fermi level in URu2Si2 has been investigated employing state-of-art laser angle-resolved photoemission spectroscopy. The observation of a narrow dispersive band near the Fermi level in the ordered state as well as its absence in a Rh-substituted sample strongly suggest that the emergence of the narrow band is a clear signature of the hidden-order transition. The temperature dependence of the narrow band, which appears at the onset of the hidden-order transition, invokes the occurrence of periodicity modification in the ordered state, which is shown for the first time by any spectroscopic probe. We compare our data to other previous studies and discuss possible implications

Ultrahigh-resolution laser photoemission study of URu₂Si₂ across the hidden-order transition

We have studied the electronic structures of URu2Si2 employing ultrahigh-resolutionlaser angle-resolved photoemission spectroscopy. The change of photoemission spectra is investigated across the hidden-ordertransition, and the emergence of a narrow band is clearly observed near the Fermi level for both (π,0) and (π,π) directions. In addition, it is shown that tuning of light's polarization allows the signal of a hole-like dispersive feature to enhance. These observations prove that laser angle-resolved photoemission spectroscopy is an effective tool for studying the evolution of electronic structures across the hidden-ordertransition in URu2Si2

Association between the SERPING1 Gene and Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy in Japanese

PURPOSE: Recently, a complement component 1 inhibitor (SERPING1) gene polymorphism was identified as a novel risk factor for age-related macular degeneration (AMD) in Caucasians. We aimed to investigate whether variations in SERPING1 are associated with typical AMD or with polypoidal choroidal vasculopathy (PCV) in a Japanese population. METHODS: We performed a case-control study in a group of Japanese patients with typical AMD (n = 401) or PCV (n = 510) and in 2 independent control groups--336 cataract patients without age-related maculopathy and 1,194 healthy Japanese individuals. Differences in the observed genotypic distribution between the case and control groups were tested using chi-square test for trend. Age and gender were adjusted using logistic regression analysis. RESULTS: We targeted rs2511989 as the haplotype-tagging single nucleotide polymorphism (SNP) for the SERPING1 gene, which was reported to be associated with the risk of AMD in Caucasians. Although we compared the genotypic distributions of rs2511989 in typical AMD and PCV patients against 2 independent control groups (cataract patients and healthy Japanese individuals), SERPING1 rs2511989 was not significantly associated with typical AMD (P = 0.932 and 0.513, respectively) or PCV (P = 0.505 and 0.141, respectively). After correction for age and gender differences based on a logistic regression model, the difference in genotypic distributions remained insignificant (P>0.05). Our sample size had a statistical power of more than 90% to detect an association of a risk allele with an odds ratio reported in the original studies for rs2511989 for developing AMD. CONCLUSIONS: In the present study, we could not replicate the reported association between SERPING1 and either neovascular AMD or PCV in a Japanese population; thus, the results suggest that SERPING1 does not play a significant role in the risk of developing AMD or PCV in Japanese