Nanometer-scale electrical characterization of stressed ultrathin SiO2 films using conducting atomic force microscopy

A conductive atomic force microscope has been used to electrically stress and to investigate the effects of degradation in the conduction properties of ultrathin (<6 nm) SiO2 films on a nanometer scale (areas of ≈100 nm2). Before oxide breakdown, switching between two states of well-defined conductivity and sudden changes of conductivity were observed, which are attributed to the capture/release of single charges in the defects generated during stress

Non-homogeneuos conduction of conductive filaments in Ni/HfO2/Si resistive switching structures observed with CAFM

Altres ajuts: ERDF/TEC2011-2792-C02-02Conductive filaments (CFs) in Ni/HfO₂/Si resistive switching structures are analysed at the nanoscale by means of Conductive Atomic Force Microscopy (CAFM). Differences in the CF conductivity are measured depending on the resistive state of the device. Moreover, for both resistance states, non-homogeneous conduction across the CF area is observed, in agreement with a tree-shaped CF

Diet and lifestyle behaviour disruption related to the pandemic was varied and bidirectional among US and UK adults participating in the ZOE COVID Study

Evidence of the impact of the COVID-19 pandemic on health behaviours in the general population is limited. In this retrospective longitudinal study including UK and US participants, we collected diet and lifestyle data pre-pandemic (896,286) and peri-pandemic (291,871) using a mobile health app, and we computed a bidirectional health behaviour disruption index. Disruption of health behaviour was higher in younger, female and socio-economically deprived participants. Loss in body weight was greater in highly disrupted individuals than in those with low disruption. There were large inter-individual changes observed in 46 health and diet behaviours measured peri-pandemic compared with pre-pandemic, but no mean change in the total population. Individuals most adherent to less healthy pre-pandemic health behaviours improved their diet quality and weight compared with those reporting healthier pre-pandemic behaviours, irrespective of relative deprivation; therefore, for a proportion of the population, the pandemic may have provided an impetus to improve health behaviours. Public policies to tackle health inequalities widened by the pandemic should continue to prioritize diet and physical activity for all, as well as more targeted approaches to support younger females and those living in economically deprived areas

Disability progression markers over 6-12 years in interferon-beta-treated multiple sclerosis patients

Objective: To investigate the association between activity during interferon-beta (IFNβ) therapy and disability outcomes in patients with relapsing–remitting multiple sclerosis (RRMS). Methods: A longitudinal study based on two previously described cohorts of IFNβ-treated RRMS patients was conducted. Patients were classified according to clinical activity after 2 years (clinical cohort) or to clinical and radiological activity after 1 year (magnetic resonance imaging (MRI) cohort). Multivariate Cox models were calculated for early disease activity predicting long-term disability. Results: A total of 516 patients from two different cohorts were included in the analyses. Persistent clinical disease activity during the first 2 years of therapy predicted severe long-term disability (clinical cohort). In the MRI cohort, modified Rio score and no or minimal evidence of disease activity (NEDA/MEDA) did not identify patients with risk of Expanded Disability Status Scale (EDSS) worsening. However, a Rio score ≥ 2 (hazard ratio (HR): 3.3, 95% confidence interval (CI): 1.7–6.4); ≥3 new T2 lesions (HR: 2.9, 95% CI: 1.5–5.6); or ≥2 Gd-enhancing lesions (HR: 2.1, 95% CI: 1.1–4) were able to identify patients with EDSS worsening. Conclusion: Although early activity during IFNβ therapy is associated with poor long-term outcomes, minimal degree of activity does not seem to be predictive of EDSS worsening over 6.7-year mean follow-up

GATA6 Activates Wnt Signaling in Pancreatic Cancer by Negatively Regulating the Wnt Antagonist Dickkopf-1

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease characterized by late diagnosis and treatment resistance. Recurrent genetic alterations in defined genes in association with perturbations of developmental cell signaling pathways have been associated with PDAC development and progression. Here, we show that GATA6 contributes to pancreatic carcinogenesis during the temporal progression of pancreatic intraepithelial neoplasia by virtue of Wnt pathway activation. GATA6 is recurrently amplified by both quantitative-PCR and fluorescent in-situ hybridization in human pancreatic intraepithelial neoplasia and in PDAC tissues, and GATA6 copy number is significantly correlated with overall patient survival. Forced overexpression of GATA6 in cancer cell lines enhanced cell proliferation and colony formation in soft agar in vitro and growth in vivo, as well as increased Wnt signaling. By contrast siRNA mediated knockdown of GATA6 led to corresponding decreases in these same parameters. The effects of GATA6 were found to be due to its ability to bind DNA, as forced overexpression of a DNA-binding mutant of GATA6 had no effects on cell growth in vitro or in vivo, nor did they affect Wnt signaling levels in these same cells. A microarray analysis revealed the Wnt antagonist Dickopf-1 (DKK1) as a dysregulated gene in association with GATA6 knockdown, and direct binding of GATA6 to the DKK1 promoter was confirmed by chromatin immunoprecipitation and electrophoretic mobility shift assays. Transient transfection of GATA6, but not mutant GATA6, into cancer cell lines led to decreased DKK1 mRNA expression and secretion of DKK1 protein into culture media. Forced overexpression of DKK1 antagonized the effects of GATA6 on Wnt signaling in pancreatic cancer cells. These findings illustrate that one mechanism by which GATA6 promotes pancreatic carcinogenesis is by virtue of its activation of canonical Wnt signaling via regulation of DKK1

Nanometer-scale electrical characterization of stressed ultrathin SiO2 films using conducting atomic force microscopy

A conductive atomic force microscope has been used to electrically stress and to investigate the effects of degradation in the conduction properties of ultrathin (<6 nm) SiO2 films on a nanometer scale (areas of ≈100 nm2). Before oxide breakdown, switching between two states of well-defined conductivity and sudden changes of conductivity were observed, which are attributed to the capture/release of single charges in the defects generated during stress

Contribution of the symptomatic lesion in establishing MS diagnosis and prognosis

Objective: To study the contribution of the symptomatic lesion in establishing multiple sclerosis (MS) diagnosis and prognosis. Methods: We performed an observational study based on a prospective clinically isolated syndrome (CIS) cohort of 1,107 patients recruited for clinical and brain MRI follow-up from 1995 to 2014. Eligible patients (n = 954) were divided into 4 groups according to baseline MRI: patients with a normal MRI (n = 290); patients with a single asymptomatic lesion (n = 18); patients with a single cord/brainstem symptomatic lesion (n = 35); and patients with more than 1 lesion (n = 611). For each group, we studied the risk of second attack, with 2005 McDonald MS and Expanded Disability Status Scale 3.0, using univariable and multivariable regression models adjusted by age, sex, oligoclonal bands, and disease-modifying treatments. We tested the diagnostic performance of a modified dissemination in space (DIS) criterion that includes symptomatic lesions in the total count and compared it to the DIS criteria (at least 1 asymptomatic lesion in at least 2 of the 4 MS characteristic MS locations) for all patients and for the subgroup of patients with brainstem or spinal cord topography. Results: Patients with a cord/brainstem single symptomatic lesion have a higher risk of second attack and disability accumulation than patients with 0 lesions but have a similar risk compared to patients with 1 asymptomatic lesion. Diagnostic properties are reasonably maintained when the symptomatic lesion qualifies for DIS. Conclusions: Despite the recommendations of the 2010 McDonald criteria, symptomatic lesions should be taken into account when considering the diagnosis and prognosis of patients with CIS