21 research outputs found

    Electrical resistivity at large temperatures: Saturation and lack thereof

    Full text link
    Many transition metal compounds show saturation of the resistivity at high temperatures, T, while the alkali-doped fullerenes and the high-Tc cuprates are usually considered to show no saturation. We present a model of transition metal compounds, showing saturation, and a model of alkali-doped fullerenes, showing no saturation. To analyze the results we use the f-sum rule, which leads to an approximate upper limit for the resistivity at large T. For some systems and at low T, the resistivity increases so rapidly that this upper limit is approached for experimental T. The resistivity then saturates. For a model of transition metal compounds with weakly interacting electrons, the upper limit corresponds to a mean free path consistent with the Ioffe-Regel condition. For a model of the high Tc cuprates with strongly interacting electrons, however, the upper limit is much larger than the Ioffe-Regel condition suggests. Since this limit is not exceeded by experimental data, the data are consistent with saturation also for the cuprates. After "saturation" the resistivity usually grows slowly. For the alkali-doped fullerenes, "saturation" can be considered to have happened already for T=0, due to orientational disorder. For these systems, however, the resistivity grows so rapidly after "saturation" that this concept is meaningless. This is due to the small band width and to the coupling to the level energies of the important phonons.Comment: 22 pages, RevTeX, 19 eps figures, additional material available at http://www.mpi-stuttgart.mpg.de/andersen/fullerene

    Identification of independent association signals and putative functional variants for breast cancer risk through fine-scale mapping of the 12p11 locus.

    Get PDF
    BACKGROUND: Multiple recent genome-wide association studies (GWAS) have identified a single nucleotide polymorphism (SNP), rs10771399, at 12p11 that is associated with breast cancer risk. METHOD: We performed a fine-scale mapping study of a 700 kb region including 441 genotyped and more than 1300 imputed genetic variants in 48,155 cases and 43,612 controls of European descent, 6269 cases and 6624 controls of East Asian descent and 1116 cases and 932 controls of African descent in the Breast Cancer Association Consortium (BCAC; http://bcac.ccge.medschl.cam.ac.uk/ ), and in 15,252 BRCA1 mutation carriers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Stepwise regression analyses were performed to identify independent association signals. Data from the Encyclopedia of DNA Elements project (ENCODE) and the Cancer Genome Atlas (TCGA) were used for functional annotation. RESULTS: Analysis of data from European descendants found evidence for four independent association signals at 12p11, represented by rs7297051 (odds ratio (OR) = 1.09, 95 % confidence interval (CI) = 1.06-1.12; P = 3 × 10(-9)), rs805510 (OR = 1.08, 95 % CI = 1.04-1.12, P = 2 × 10(-5)), and rs1871152 (OR = 1.04, 95 % CI = 1.02-1.06; P = 2 × 10(-4)) identified in the general populations, and rs113824616 (P = 7 × 10(-5)) identified in the meta-analysis of BCAC ER-negative cases and BRCA1 mutation carriers. SNPs rs7297051, rs805510 and rs113824616 were also associated with breast cancer risk at P < 0.05 in East Asians, but none of the associations were statistically significant in African descendants. Multiple candidate functional variants are located in putative enhancer sequences. Chromatin interaction data suggested that PTHLH was the likely target gene of these enhancers. Of the six variants with the strongest evidence of potential functionality, rs11049453 was statistically significantly associated with the expression of PTHLH and its nearby gene CCDC91 at P < 0.05. CONCLUSION: This study identified four independent association signals at 12p11 and revealed potentially functional variants, providing additional insights into the underlying biological mechanism(s) for the association observed between variants at 12p11 and breast cancer risk.UK funding includes Cancer Research UK and NIH.This is the final version of the article. It first appeared from BioMed Central via http://dx.doi.org/10.1186/s13058-016-0718-

    Total hip arthroplasty and sexual activity: a systematic review

    No full text
    Hip discomfort due to degenerative pathologies causes limitations in the everyday activities of patients, including sexual activity. To address such limitations, patients are usually treated with total hip arthroplasty (THA). The aim of this systematic review was to investigate the success of this surgical procedure to ameliorate sexual activity of patients. We performed a comprehensive research of four electronic databases for articles pertaining to the benefits of THA on sexual activity. Exclusion criteria included articles not in English. The search initially yielded 34 articles. Two authors subsequently read all abstracts and excluded all studies unrelated to the topic, leaving 16 articles for further evaluation. Sixteen articles filtered by orthopaedic departments were included in this review. A total of 2391 patients were considered. Pre- and postoperative reports on sexual concerns have been evaluated and compared. The current literature suggests that sexual life is improved after THA. Patient education regarding postoperative expectations and resumption of sexual activity is severely lacking and the majority of surgeons offer little or no information on the subject. Specifically designed studies on the subject are required to evaluate the effects of surgery and approaches on postoperative restrictions. © 2020, Istituto Ortopedico Rizzoli

    EAES rapid guideline: updated systematic review, network meta-analysis, CINeMA and GRADE assessment, and evidence-informed European recommendations on the management of common bile duct stones.

    No full text
    BACKGROUND: Choledocholithiasis presents in a considerable proportion of patients with gallbladder disease. There are several management options, including preoperative or intraoperative endoscopic cholangiopancreatography (ERCP), and laparoscopic common bile duct exploration (LCBDE). OBJECTIVE: To develop evidence-informed, interdisciplinary, European recommendations on the management of common bile duct stones in the context of intact gallbladder with a clinical decision to intervene to both the gallbladder and the common bile duct stones. METHODS: We updated a systematic review and network meta-analysis of LCBDE, preoperative, intraoperative, and postoperative ERCP. We formed evidence summaries using the GRADE and the CINeMA methodology, and a panel of general surgeons, gastroenterologists, and a patient representative contributed to the development of a GRADE evidence-to-decision framework to select among multiple interventions. RESULTS: The panel reached unanimous consensus on the first Delphi round. We suggest LCBDE over preoperative, intraoperative, or postoperative ERCP, when surgical experience and expertise are available; intraoperative ERCP over LCBDE, preoperative or postoperative ERCP, when this is logistically feasible in a given healthcare setting; and preoperative ERCP over LCBDE or postoperative ERCP, when intraoperative ERCP is not feasible and there is insufficient experience or expertise with LCBDE (weak recommendation). The evidence summaries and decision aids are available on the platform MAGICapp ( https://app.magicapp.org/#/guideline/nJ5zyL ). CONCLUSION: We developed a rapid guideline on the management of common bile duct stones in line with latest methodological standards. It can be used by healthcare professionals and other stakeholders to inform clinical and policy decisions. GUIDELINE REGISTRATION NUMBER: IPGRP-2022CN170

    La filologia classica e umanistica di Remigio Sabbadini

    No full text
    Understanding the regulatory landscape of the human genome is a central question in complex trait genetics. Most single-nucleotide polymorphisms (SNPs) associated with cancer risk lie in non-protein-coding regions, implicating regulatory DNA elements as functional targets of susceptibility variants. Here, we describe genome-wide annotation of regions of open chromatin and histone modification in fallopian tube and ovarian surface epithelial cells (FTSECs, OSECs), the debated cellular origins of high-grade serous ovarian cancers (HGSOCs) and in endometriosis epithelial cells (EECs), the likely precursor of clear cell ovarian carcinomas (CCOCs). The regulatory architecture of these cell types was compared with normal human mammary epithelial cells and LNCaP prostate cancer cells. We observed similar positional patterns of global enhancer signatures across the three different ovarian cancer precursor cell types, and evidence of tissue-specific regulatory signatures compared to non-gynecological cell types. We found significant enrichment for risk-associated SNPs intersecting regulatory biofeatures at 17 known HGSOC susceptibility loci in FTSECs (P = 3.8 × 10(-30)), OSECs (P = 2.4 × 10(-23)) and HMECs (P = 6.7 × 10(-15)) but not for EECs (P = 0.45) or LNCaP cells (P = 0.88). Hierarchical clustering of risk SNPs conditioned on the six different cell types indicates FTSECs and OSECs are highly related (96% of samples using multi-scale bootstrapping) suggesting both cell types may be precursors of HGSOC. These data represent the first description of regulatory catalogues of normal precursor cells for different ovarian cancer subtypes, and provide unique insights into the tissue specific regulatory variation with respect to the likely functional targets of germline genetic susceptibility variants for ovarian cancer

    Cell-type-specific enrichment of risk-associated regulatory elements at ovarian cancer susceptibility loci

    No full text
    Contains fulltext : 154725.pdf (publisher's version ) (Closed access)Understanding the regulatory landscape of the human genome is a central question in complex trait genetics. Most single-nucleotide polymorphisms (SNPs) associated with cancer risk lie in non-protein-coding regions, implicating regulatory DNA elements as functional targets of susceptibility variants. Here, we describe genome-wide annotation of regions of open chromatin and histone modification in fallopian tube and ovarian surface epithelial cells (FTSECs, OSECs), the debated cellular origins of high-grade serous ovarian cancers (HGSOCs) and in endometriosis epithelial cells (EECs), the likely precursor of clear cell ovarian carcinomas (CCOCs). The regulatory architecture of these cell types was compared with normal human mammary epithelial cells and LNCaP prostate cancer cells. We observed similar positional patterns of global enhancer signatures across the three different ovarian cancer precursor cell types, and evidence of tissue-specific regulatory signatures compared to non-gynecological cell types. We found significant enrichment for risk-associated SNPs intersecting regulatory biofeatures at 17 known HGSOC susceptibility loci in FTSECs (P = 3.8 x 10(-30)), OSECs (P = 2.4 x 10(-23)) and HMECs (P = 6.7 x 10(-15)) but not for EECs (P = 0.45) or LNCaP cells (P = 0.88). Hierarchical clustering of risk SNPs conditioned on the six different cell types indicates FTSECs and OSECs are highly related (96% of samples using multi-scale bootstrapping) suggesting both cell types may be precursors of HGSOC. These data represent the first description of regulatory catalogues of normal precursor cells for different ovarian cancer subtypes, and provide unique insights into the tissue specific regulatory variation with respect to the likely functional targets of germline genetic susceptibility variants for ovarian cancer

    Breast and ovarian cancer risks to carriers of the BRCA1 5382insC and 185delAG and BRCA2 6174delT mutations: a combined analysis of 22 population based studies

    No full text
    A recent report estimated the breast cancer risks in carriers of the three Ashkenazi founder mutations to be higher than previously published estimates derived from population based studies. In an attempt to confirm this, the breast and ovarian cancer risks associated with the three Ashkenazi founder mutations were estimated using families included in a previous meta-analysis of populatrion based studies. The estimated breast cancer risks for each of the founder BRCA1 and BRCA2 mutations were similar to the corresponding estimates based on all BRCA1 or BRCA2 mutations in the meta-analysis. These estimates appear to be consistent with the observed prevalence of the mutations in the Ashkenazi Jewish population
    corecore