219 research outputs found

    Critical fluctuation conductivity in layered superconductors in strong electric field

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    The paraconductivity, originating from critical superconducting order-parameter fluctuations in the vicinity of the critical temperature in a layered superconductor is calculated in the frame of the self-consistent Hartree approximation, for an arbitrarily strong electric field and zero magnetic field. The paraconductivity diverges less steep towards the critical temperature in the Hartree approximation than in the Gaussian one and it shows a distinctly enhanced variation with the electric field. Our results indicate that high electric fields can be effectively used to suppress order-parameter fluctuations in high-temperature superconductors.Comment: 11 pages, 2 figures, to be published in Phys. Rev.

    Microscopic theory of the pseudogap and Peierls transition in quasi-one-dimensional materials

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    The problem of deriving from microscopic theory a Ginzburg-Landau free energy functional to describe the Peierls or charge-density-wave transition in quasi-one-dimensional materials is considered. Particular attention is given to how the thermal lattice motion affects the electronic states. Near the transition temperature the thermal lattice motion produces a pseudogap in the density of states at the Fermi level. Perturbation theory diverges and the traditional quasi-particle or Fermi liquid picture breaks down. The pseudogap causes a significant modification of the coefficients in the Ginzburg-Landau functional from their values in the rigid lattice approximation, which neglects the effect of the thermal lattice motion. To appear in Physical Review B.Comment: 21 pages, RevTeX, 5 figures in uuencoded compressed tar fil

    ONCOR: design of the Dutch cardio-oncology registry

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    Background: The relative new subspecialty ‘cardio-oncology’ was established to meet the growing demand for an interdisciplinary approach to the management of cancer therapy–related cardiovascular adverse events. In recent years, specialised cardio-oncology services have been implemented worldwide, which all strive to improve the cardiovascular health of cancer patients. However, limited data are currently available on the outcomes and experiences of these specialised services, and optimal strategies for cardio-oncological care have not been established. / Aim: The ONCOR registry has been created for prospective data collection and evaluation of cardio-oncological care in daily practice. / Methods: Dutch hospitals using a standardised cardio-oncology care pathway are included in this national, multicentre, observational cohort study. All patients visiting these cardio-oncology services are eligible for study inclusion. Data collection at baseline consists of the (planned) cancer treatment and the cardiovascular risk profile, which are used to estimate the cardiotoxic risk. Information regarding invasive and noninvasive tests is collected during the time patients receive cardio-oncological care. Outcome data consist of the incidence of cardiovascular complications and major adverse cardiac events, and the impact of these events on the oncological treatment. / Discussion: Outcomes of the ONCOR registry may aid in gaining more insight into the incidence of cancer therapy–related cardiovascular complications. The registry facilitates research on mechanisms of cardiovascular complications and on diagnostic, prognostic and therapeutic strategies. In addition, it provides a platform for future (interventional) studies. Centres with cardio-oncology services that are interested in contributing to the ONCOR registry are hereby invited to participate

    Original Article

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    Objective: Glucagon is well known to regulate blood glucose but may be equally important for amino acid metabolism. Plasma levels of amino acids are regulated by glucagon-dependent mechanism(s), while amino acids stimulate glucagon secretion from alpha cells, completing the recently described liver-alpha cell axis. The mechanisms underlying the cycle and the possible impact of hepatic steatosis are unclear. Methods: We assessed amino acid clearance in vivo in mice treated with a glucagon receptor antagonist (GRA), transgenic mice with 95% reduction in alpha cells, and mice with hepatic steatosis. In addition, we evaluated urea formation in primary hepatocytes from ob/ob mice and humans, and we studied acute metabolic effects of glucagon in perfused rat livers. We also performed RNA sequencing on livers from glucagon receptor knock-out mice and mice with hepatic steatosis. Finally, we measured individual plasma amino acids and glucagon in healthy controls and in two independent cohorts of patients with biopsy-verified non-alcoholic fatty liver disease (NAFLD). Results: Amino acid clearance was reduced in mice treated with GRA and mice lacking endogenous glucagon (loss of alpha cells) concomitantly with reduced production of urea. Glucagon administration markedly changed the secretion of rat liver metabolites and within minutes increased urea formation in mice, in perfused rat liver, and in primary human hepatocytes. Transcriptomic analyses revealed that three genes responsible for amino acid catabolism (Cps1, Slc7a2, and Slc38a2) were downregulated both in mice with hepatic steatosis and in mice with deletion of the glucagon receptor. Cultured ob/ob hepatocytes produced less urea upon stimulation with mixed amino acids, and amino acid clearance was lower in mice with hepatic steatosis. Glucagon-induced ureagenesis was impaired in perfused rat livers with hepatic steatosis. Patients with NAFLD had hyperglucagonemia and increased levels of glucagonotropic amino acids, including alanine in particular. Both glucagon and alanine levels were reduced after diet-induced reduction in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR, a marker of hepatic steatosis). Conclusions: Glucagon regulates amino acid metabolism both non-transcriptionally and transcriptionally. Hepatic steatosis may impair glucagon-dependent enhancement of amino acid catabolism. (C) 2020 The Author(s). Published by Elsevier GmbH

    Acquisition of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) carriage after exposure to systemic antimicrobials during travel: systematic review and meta-analysis

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    BACKGROUND: International travel is an important risk factor for colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). Antimicrobial use during travel likely amplifies this risk, yet to what extent, and whether it varies by antimicrobial class, has not been established. METHODS: We conducted a systematic review that included prospective cohorts reporting both receipt of systemic antimicrobials and acquired ESBL-PE isolated from stool or rectum during international travel. We performed a random effects meta-analysis to estimate odds of acquiring ESBL-PE due to antimicrobials during travel, overall and by antimicrobial class. RESULTS: Fifteen studies were included. The study population was mainly female travellers from high income countries recruited primarily from travel clinics. Participants travelled most frequently to Asia and Africa with 10% reporting antimicrobial use during travel. The combined odds ratio (OR) for ESBL-PE acquisition during travel was 2.37 for antimicrobial use overall (95% confidence interval [CI], 1.69 to 3.33), but there was substantial heterogeneity between studies. Fluoroquinolones were the antibiotic class associated with the highest combined OR of ESBL-PE acquisition, compared to no antimicrobial use (OR 4.68, 95% CI, 2.34 to 9.37). CONCLUSIONS: The risk of ESBL-PE colonization during travel is increased substantially with exposure to antimicrobials, especially fluoroquinolones. While a small proportion of colonized individuals will develop a resistant infection, there remains the potential for onward spread among returning travellers. Public health efforts to decrease inappropriate antimicrobial usage during travel are warranted

    Mid- and Late-Life Diabetes in Relation to the Risk of Dementia: A Population-Based Twin Study

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    OBJECTIVE—We aimed to verify the association between diabetes and the risk of dementia, Alzheimer's disease, and vascular dementia in twins and to explore whether genetic and early-life environmental factors could contribute to this association

    Butyrate down-regulates CD44 transcription and liver colonisation in a highly metastatic human colon carcinoma cell line

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    Over-expression of the adhesion molecule CD44 and its splice variants, especially CD44v6, is associated with poor prognosis and metastasis. We aimed at regulating the expression of CD44 in the highly metastatic human colon cancer cell line HM7 and thereby affecting its metastatic ability. HM7 cells show constitutive expression of CD44 standard and variants isoforms, which were significantly down-regulated by treatment with butyrate. Butyrate significantly inhibited transcription of the CD44 gene and abolished epidermal growth factor-mediated up-regulation of the reporter gene luciferase subcloned upstream to the CD44 promoter (−1.1 kb) and transfected to HM7 cells. Nuclear proteins from butyrate-treated cells bound to an epidermal growth factor receptor element motif present in the CD44 promoter. Epidermal growth factor receptor element-site directed mutations eliminated the inducibility of the luciferase reporter gene and did not allowed binding of nuclear proteins harvested from butyrate-treated cells. Butyrate induced CD44 gene repression by specifically interacting with an epidermal growth factor receptor element nuclear transcriptional factor. This interaction affects CD44 transcriptional activity vis-à-vis in vivo metastatic ability of HM7 cells. These results provide additional insight into the anticarcinogenic properties of butyrate

    Assessment of cognitive status in patients with type 2 diabetes through the mini-mental status examination: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Diabetes is considered an independent risk factor for cognitive impairment and some studies observed through neuropsychological tests that cognitive disfunction affects both elderly and younger patients with diabetes. The aims of this study were to evaluate the cognitive status of outpatients with type 2 diabetes and to evaluate factors associated with impaired function.</p> <p>Methods</p> <p>A cross-sectional study was conducted in a group of type 2 diabetic outpatients. They were asked to undergo the Mini-Mental State Examination (MMSE) during routine ambulatory visits between April 2006 and January 2007, with the highest pontuation of the test being 30 points. Patients were classified as having possible dementia according to years of study. Exclusion criteria were blindness, illiterately, stroke, Alzheimer disease and psychiatric disorder. Results are presented as median (interquartile range) or mean ± SD.</p> <p>Results</p> <p>The study group was composed of 346 type 2 diabetic outpatients (216 females), aged 58,6 ± 12,1 years and with duration of diabetes of 12,3 ± 9,1 years. Hypertension was present in 77,2%. The total MMSE score achieved was 26 points (16 - 30) and was correlated with years of study (R<sup>2 </sup>= 0,39, p < 0,001) and 'per capita' income (R<sup>2 </sup>= 0,22, p < 0,0001) and duration of diabetes (R2 = - 0,13, p = 0,01). Patients who needed help to take their medications obtained worst performance in the MMSE (23,16 ± 3,55 <it>vs </it>25,7 ± 2,84, p < 0,01) and were more likely to present possible dementia (p < 0,01). Forty two subjects (12.1%) had diagnosis of possible dementia and this was also associated with years of study (p = 0,045). No association was observed between possible dementia and total MMSE scores with A1C levels.</p> <p>Conclusions</p> <p>We conclude that patients with type 2 diabetes should be regularly evaluated for their cognitive function, because duration of disease could be associated with decline in cognition. The early implementation of mini mental which is a simple method of execution can be done to detect early stages of dementia. This test could be an important tool to access the ability of patient to understand their disease and treatment.</p
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