313 research outputs found
Subkelvin tunneling spectroscopy showing Bardeen-Cooper-Schrieffer superconductivity in heavily boron-doped silicon epilayers
Scanning tunneling spectroscopies in the subKelvin temperature range were
performed on superconducting Silicon epilayers doped with Boron in the atomic
percent range. The resulting local differential conductance behaved as expected
for a homogeneous superconductor, with an energy gap dispersion below +/- 10%.
The spectral shape, the amplitude and temperature dependence of the
superconductivity gap follow the BCS model, bringing further support to the
hypothesis of a hole pairing mechanism mediated by phonons in the weak coupling
limit.Comment: 4 pages, 3 figure
Mortality risk and mental disorders: longitudinal results from the Upper Bavarian Study
The object of the study was the assessment of the mortality risk for persons with a mental disorder in an unselected representative community sample assessed longitudinally. Subjects from a rural area in Upper Bavaria (Germany) participated in semi-structured interviews conducted by research physicians in the 1970s (first assessment) and death-certificate diagnoses were obtained after an interval up to 13 years later. The sample consisted of 1668 community residents aged 15 years and over. Cox regression estimates resulted in an odds ratio of 1·35 (confidence interval 1·01 to 1·81) for persons with a mental disorder classified as marked to very severe. The odds ratio increased with increasing severity of mental illness from 1·04 for mild disorders, 1·30 for marked disorders, to 1·64 for severe or very severe disorders. The relative risk (odds ratio) for persons with a mental disorder only and no somatic disorder was 1·22, for persons with only a somatic disorder 2·00, and for those with both a mental and a somatic disorder 2·13. The presence of somatic illness was responsible for most of the excess mortality. Somatic disorders associated with excess mortality in mental disorders were diseases of the nervous system or sensory organs, diseases of the circulatory system, diseases of the gastrointestinal tract, and diseases of the skeleton, muscles and connective tissue (ICD-8). Thus, while mental illness alone had a limited effect on excess mortality, comorbidity with certain somatic disorders had a significant effec
Band structure parameters of metallic diamond from angle-resolved photoemission spectroscopy
International audienceThe electronic band structure of heavily boron doped diamond was investigated by angle-resolved photoemission spectroscopy on (100)-oriented epilayers. A unique set of Luttinger parameters was deduced from a comparison of the experimental band structure of metallic diamond along the Delta (GammaX) and Sigma(GammaK) high-symmetry directions of the reciprocal space, with theoretical band structure calculations performed both within the local density approximation and by an analytical k·p approach. In this way, we were able to describe the experimental band structure over a large three-dimensional region of the reciprocal space and to estimate hole effective masses in agreement with previous theoretical and experimental papers
Acoelomorpha: earliest branching bilaterians or deuterostomes?
The Acoelomorpha is an animal group comprised by nearly 400 species of misleadingly inconspicuous flatworms. Despite this, acoelomorphs have been at the centre of a heated debate about the origin of bilaterian animals for 150 years. The animal tree of life has undergone major changes during the last decades, thanks largely to the advent of molecular data together with the development of more rigorous phylogenetic methods. There is now a relatively robust backbone of the animal tree of life. However, some crucial nodes remain contentious, especially the node defining the root of Bilateria. Some studies situate Acoelomorpha (and Xenoturbellida) as the sister group of all other bilaterians, while other analyses group them within the deuterostomes which instead suggests that the last common bilaterian ancestor directly gave rise to deuterostomes and protostomes. The resolution of this node will have a profound impact on our understanding of animal/bilaterian evolution. In particular, if acoelomorphs are the sister group to Bilateria, it will point to a simple nature for the first bilaterian. Alternatively, if acoelomorphs are deuterostomes, this will imply that they are the result of secondary simplification. Here, we review the state of this question and provide potential ways to solve this long-standing issue. Specifically, we argue for the benefits of (1) obtaining additional genomic data from acoelomorphs, in particular from taxa with slower evolutionary rates; (2) the development of new tools to analyse the data; and (3) the use of metagenomics or metatranscriptomics data. We believe the combination of these three approaches will provide a definitive answer as to the position of the acoelomorphs in the animal tree of life
Ancestry of the Brazilian TP53 c.1010G>A (p.Arg337His, R337H) founder mutation : clues from haplotyping of short tandem repeats on Chromosome 17p
Rare germline mutations in TP53 (17p13.1) cause a highly penetrant predisposition to a specific spectrum of early cancers, defining the Li-Fraumeni Syndrome (LFS). A germline mutation at codon 337 (p.Arg337His, c1010G>A) is found in about 0.3% of the population of Southern Brazil. This mutation is associated with partially penetrant LFS traits and is found in the germline of patients with early cancers of the LFS spectrum unselected for familial his- tory. To characterize the extended haplotypes carrying the mutation, we have genotyped 9 short tandem repeats on chromosome 17p in 12 trios of Brazilian p.Arg337His carriers. Results confirm that all share a common ancestor haplotype of Caucasian/Portuguese-Ibe- ric origin, distant in about 72–84 generations (2000 years assuming a 25 years intergenera- tional distance) and thus pre-dating European migration to Brazil. So far, the founder p. Arg337His haplotype has not been detected outside Brazil, with the exception of two resi- dents of Portugal, one of them of Brazilian origin. On the other hand, increased meiotic recombination in p.Arg337His carriers may account for higher than expected haplotype diversity. Further studies comparing haplotypes in populations of Brazil and of other areas of Portuguese migration are needed to understand the historical context of this mutation in Brazil.This study was funded by grant # 478430/2012-4 from CNPq (RFA MCT/CNPq - No 14/2012; Universal), Brazil.We would like to thank UFRGS, UFPA, AC Camargo, HC Barretos and University of Minho for their support during this work
HER2 status and response to neoadjuvant anti-HER2 treatment among patients with breast cancer and Li-Fraumeni syndrome
Background: Breast cancer (BC) is the most common cancer among females with Li-Fraumeni syndrome (LFS), but available data on LFS-related BC characteristics are derived from small retrospective cohorts. Prior work has demonstrated a high proportion of HER2-positive BCs, but our understanding of how HER2-positive LFS BCs respond to anti-HER2 treatments is limited. Methods: BCs diagnosed in patients with germline TP53 variants between 2002–2022 were assembled from three institutions. Hormone receptor (HR) and HER2 expression were retrieved from pathology records. Pathologic complete response (pCR) was defined as ypT0/is ypN0. Results: A total of 264 BCs were identified among 232 patients with LFS: 211 (79.9 %) were invasive carcinomas, of which 106 were HER2-positive. Among HER2-positive BCs, most tumors co-expressed HRs (72.6 %) and were more frequent among those diagnosed at younger age (p < 0.001). Mastectomy was the preferred surgical approach among women with nonmetastatic cancers (77.8 %) and most received anti-HER2 targeted therapy (74.7 %). Among 38 patients receiving neoadjuvant therapy with available post-treatment pathology reports, 27 (71.1 %) achieved pCR: 18/26 (69.2 %) among HR-positive and 7/10 (70.0 %) HR-negative. The rate of pCR was 84.6 % among patients treated with an anthracycline-free regimen (all received trastuzumab). Among classifiable HER2-negative BCs (n = 77), 31 (40.3 %) were HER2-low and 46 (59.7 %) HER2-zero. Conclusions: Among females with LFS and BC, HER2-positive subtype was associated with younger age at diagnosis and a predominant HR-positivity. Favorable pCR rates were observed among those receiving neoadjuvant HER2-directed therapies, for both HR-positive and negative tumors. These data may inform the counseling and care of patients with LFS
Occupational Sex Segregation and Management-Level Wages in Germany: What Role Does Firm Size Play?
The paper analyzes the gender pay gap in private-sector management positions based on German panel data and using fixed-effects models. It deals with the effect of occupational sex segregation on wages, and the extent to which wage penalties for managers in predominantly female occupations are moderated by firm size. Drawing on economic and organizational approaches and the devaluation of women's work, we find wage penalties for female occupations in management only in large firms. This indicates a pronounced devaluation of female occupations, which might be due to the longer existence, stronger formalization, or more established old-boy networks of large firms
Die PASS-Panelbefragung nach sechs Wellen
The aim of the Panel Study 'Labour Market and Social Security' (PASS) is to provide a database which allows analysing the dynamics of welfare benefits receipt after the introduction of the Unemployment Benefits II in Germany in 2005. This entails the take up and ending of benefits receipt as well as the social situation of households and individuals receiving benefits, their subjective ways of coping with the situation and the contact to institutions providing the basic income support. PASS is set up as a household panel study with a sample of approx. 10,000 households interviewed in each wave. In addition to household interviews with the heads of the households about 15,000 interviews with individual household members aged 15 and older are carried out. This article provides an overview of the first six waves of PASS. It focuses on the survey's main goals, the questionnaire, the sampling and study design, the number of interviews, data access and methodological research on PASS. The article closes by describing the outlook for future developments
Mortality risk and mental disorders: longitudinal results from the Upper Bavarian Study
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