The role of oxygen vacancies on the structure and the density of states of iron doped zirconia

In this paper we study, both with theoretical and experimental approach, the effect of iron doping in zirconia. Combining density functional theory (DFT) simulations with the experimental characterization of thin films, we show that iron is in the Fe3+ oxidation state and accordingly that the films are rich in oxygen vacancies (VO). VO favor the formation of the tetragonal phase in doped zirconia (ZrO2:Fe) and affect the density of state at the Fermi level as well as the local magnetization of Fe atoms. We also show that the Fe(2p) and Fe(3p) energy levels can be used as a marker for the presence of vacancies in the doped system. In particular the computed position of the Fe(3p) peak is strongly sensitive to the VO to Fe atoms ratio. A comparison of the theoretical and experimental Fe(3p) peak position suggests that in our films this ratio is close to 0.5. Besides the interest in the material by itself, ZrO2:Fe constitutes a test case for the application of DFT on transition metals embedded in oxides. In ZrO2:Fe the inclusion of the Hubbard U correction significantly changes the electronic properties of the system. However the inclusion of this correction, at least for the value U = 3.3 eV chosen in the present work, worsen the agreement with the measured photo-emission valence band spectra.Comment: 24 pages, 8 figure

Exploiting magnetic properties of Fe doping in zirconia

In this study we explore, both from theoretical and experimental side, the effect of Fe doping in ZrO2 (ZrO2:Fe). By means of first principles simulation we study the magnetization density and the magnetic interaction between Fe atoms. We also consider how this is affected by the presence of oxygen vacancies and compare our findings with models based on impurity band and carrier mediated magnetic interaction. Experimentally thin films (~ 20 nm) of ZrO2:Fe at high doping concentration are grown by atomic layer deposition. We provide experimental evidence that Fe is uniformly distributed in the ZrO2 by transmission electron microscopy and energy dispersive X-ray mapping, while X-ray diffraction evidences the presence of the fluorite crystal structure. Alternating gradient force magnetometer measurements show magnetic signal at room temperature, however with low magnetic moment per atom. Results from experimental measures and theoretical simulations are compared.Comment: 8 pages, 9 figures. JEMS 201

Burnout in cardiac anesthesiologists. results from a national survey in italy

Objective: There is increasing burnout incidence among medical disciplines, and physicians working in emergency settings seem at higher risk. Cardiac anesthesiology is a stressful anesthesiology subspecialty dealing with high-risk patients. The authors hypothesized a high risk of burnout in cardiac anesthesiologists. Design: National survey conducted on burnout Setting: Italian cardiac centers. Participants: Cardiac anesthesiologists. Interventions: The authors administered via email an anonymous questionnaire divided into 3 parts. The first 2 parts evaluated workload and private life. The third part consisted of the Maslach Burnout Inventory test with its 3 constituents: high emotional exhaustion, high depersonalization, and low personal accomplishment. Measurements and Main Results: The authors measured the prevalence and risk of burnout through the Maslach Burnout Inventory questionnaire and analyzed factors influencing burnout. Among 670 contacts from 71 centers, 382 cardiac anesthesiologists completed the survey (57%). The authors found the following mean Maslach Burnout Inventory values: 14.5 ± 9.7 (emotional exhaustion), 9.1 ± 7.1 (depersonalization), and 33.7 ± 8.9 (personal accomplishment). A rate of 34%, 54%, and 66% of respondents scored in “high” or “moderate-high” risk of burnout (emotional exhaustion, depersonalization, and personal accomplishment, respectively). The authors found that, if offered to change subspecialty, 76% of respondents would prefer to remain in cardiac anesthesiology. This preference and parenthood were the only 2 investigated factors with a protective effect against all components of burnout. Significantly lower burnout scores were found in more experienced anesthesiologists. Conclusion: A relatively high incidence of burnout was found in cardiac anesthesiologists, especially regarding high depersonalization and low personal accomplishment. Nonetheless, most of the respondents would choose to remain in cardiac anesthesiology

Case Study: Valle Camonica and the Adamello Park

Capitolo introdduttivo all'area di studio scelta nelle Alpi meridionali come focus per l'ozono e il rischio incendi. Presenta le propiezioni climatiche nell'arfea fino alla fine del secolo

Circulating MicroRNA-15a Associates With Retinal Damage in Patients With Early Stage Type 2 Diabetes

: Circulating microRNAs are potential biomarkers of type 2 diabetes mellitus (T2DM) and related complications. Here, we investigated the association of microRNA-15a with early retinal damage in T2DM. A cohort of untreated subjects screened for intermediate/high risk of T2DM, according to a score assessment questionnaire, and then recognized to have a normal (NGT) or impaired (IGT) glucose tolerance or T2DM was studied. The thickness of the ganglion cell complex (GCC), an early marker of retinal degeneration anteceding overt retinopathy was assessed by Optical Coherence Tomography. Total and extracellular vesicles (EV)-associated microRNA-15a quantity was measured in plasma by real time PCR. MicroRNA-15a level was significantly higher in subjects with IGT and T2DM compared with NGT. MicroRNA-15a abundance was correlated to body mass index and classical diabetes biomarkers, including fasting glucose, HbA1c, insulinemia, and HOMA-IR. Moreover, GCC thickness was significantly reduced in IGT and T2DM subjects compared with NGT controls. Importantly, total microRNA-15a correlated with GCC in IGT subjects, while in T2DM subjects, EV-microRNA-15a negatively correlated with GCC, suggesting that microRNA-15a may monitor initial retinal damage. The assessment of plasma microRNA-15a may help refining risk assessment and secondary prevention in patients with preclinical T2DM

MicroRNA-21/PDCD4 proapoptotic signaling from circulating CD34+ cells to vascular endothelial cells:a potential contributor to adverse cardiovascular outcomes in patients with critical limb ischemia

Dataset related to the article with title: MicroRNA-21/PDCD4 proapoptotic signaling from circulating CD34+ cells to vascular endothelial cells: a potential contributor to adverse cardiovascular outcomes in patients with critical limb ischemia By:Gaia Spinetti1, Elena Sangalli1, Elena Tagliabue1, Davide Maselli1, Ornella Colpani1, David Ferland-McCollough2, Franco Carnelli1, Patrizia Orlando1, Agostino Paccagnella3, Anna Furlan3, Piero Maria Stefani3, Luisa Sambado3, Maria Sambataro3, and Paolo Madeddu2. 1IRCCS MultiMedica, Milan, Italy; 2University of Bristol, Bristol, UK, 3Ca Foncello Hospital, Treviso, Italy. Diabetes Care. 2020 Jul;43(7):1520-1529. doi: 10.2337/dc19-2227. Epub 2020 May 1. Abstract Objective. In patients with type 2 diabetes (T2D) and critical limb ischemia (CLI), migration of circulating CD34+ cells predicted cardiovascular mortality at 18 months post-revascularization. This study aimed to provide long-term validation and mechanistic understanding of the biomarker. Research Design and Methods. The association between CD34+ cell migration and cardiovascular mortality was reassessed at 6 years post-revascularization. In a new series of T2D-CLI and control subjects, immuno-sorted bone marrow (BM)-CD34+ cells were profiled for microRNA expression and assessed for apoptosis and angiogenesis activity. The differentially regulated microRNA-21, and its pro-apoptotic target PDCD4, were titrated to verify their contribution in transferring damaging signals from CD34+ cells to endothelial cells. Results. Multivariable regression analysis confirmed CD34+ cell migration forecasts long-term cardiovascular mortality. CD34+ cells from T2D-CLI patients were more apoptotic and less proangiogenic than controls and featured microRNA-21 downregulation, modulation of several long non-coding RNAs acting as microRNA-21 sponges, and upregulation of the microRNA-21 proapoptotic target PDCD4. Silencing miR-21 in control CD34+ cells phenocopied the T2D-CLI cell behavior. In coculture, T2D-CLI CD34+ cells imprinted naïve endothelial cells, increasing apoptosis, reducing network formation, and modulating the TUG1 sponge/microRNA-21/PDCD4 axis. Silencing PDCD4 or scavenging ROS protected endothelial cells from the negative influence of T2D-CLI CD34+ cells Conclusions. Migration of CD34+ cells predicts long-term cardiovascular mortality in T2D-CLI patients. An altered paracrine signalling conveys anti-angiogenic and pro-apoptotic features from CD34+ cells to the endothelium. This damaging interaction may increase the risk for life-threatening complications

A systematic study of the valence electronic structure of cyclo(Gly–Phe), cyclo(Trp–Tyr) and cyclo(Trp–Trp) dipeptides in the gas phase

The electronic energy levels of cyclo(glycine–phenylalanine), cyclo(tryptophan–tyrosine) and cyclo(tryptophan–tryptophan) dipeptides are investigated with a joint experimental and theoretical approach. Experimentally, valence photoelectron spectra in the gas phase are measured using VUV radiation. Theoretically, we first obtain low-energy conformers through an automated conformer–rotamer ensemble sampling scheme based on tight-binding simulations. Then, different first principles computational schemes are considered to simulate the spectra: Hartree–Fock (HF), density functional theory (DFT) within the B3LYP approximation, the quasi-particle GW correction, and the quantumchemistry CCSD method. Theory allows assignment of the main features of the spectra. A discussion on the role of electronic correlation is provided, by comparing computationally cheaper DFT scheme (and GW) results with the accurate CCSD method

Increased prevalence of unstable HLA-C variants in HIV-1 rapid-progressor patients

HIV-1 infection in the absence of treatment results in progression toward AIDS. Host genetic factors play a role in HIV-1 pathogenesis, but complete knowledge is not yet available. Since less-expressed HLA-C variants are associated with poor HIV-1 control and unstable HLA-C variants are associated with higher HIV-1 infectivity, we investigated whether there was a correlation between the different stages of HIV-1 progression and the presence of specific HLA-C allotypes. HLA-C genotyping was performed using allele-specific PCR by analyzing a treatment-naïve cohort of 96 HIV-1-infected patients from multicentric cohorts in the USA, Canada, and Brazil. HIV-1-positive subjects were classified according to their different disease progression status as progressors (Ps, n = 48), long-term non-progressors (LTNPs, n = 37), and elite controllers (ECs, n = 11). HLA-C variants were classified as stable or unstable according to their binding stability to β2-microglobulin/peptide complex. Our results showed a significant correlation between rapid progression to AIDS and the presence of two or one unstable HLA-C variants (p-value: 0.0078, p-value: 0.0143, respectively). These findings strongly suggest a link between unstable HLA-C variants both at genotype and at allele levels and rapid progression to AIDS. This work provides further insights into the impact of host genetic factors on AIDS progression

Dysregulation of MS risk genes and pathways at distinct stages of disease

OBJECTIVE: To perform systematic transcriptomic analysis of multiple sclerosis (MS) risk genes in peripheral blood mononuclear cells (PBMCs) of subjects with distinct MS stages and describe the pathways characterized by dysregulated gene expressions. METHODS: We monitored gene expression levels in PBMCs from 3 independent cohorts for a total of 297 cases (including clinically isolated syndromes (CIS), relapsing-remitting MS, primary and secondary progressive MS) and 96 healthy controls by distinct microarray platforms and quantitative PCR. Differential expression and pathway analyses for distinct MS stages were defined and validated by literature mining. RESULTS: Genes located in the vicinity of MS risk variants displayed altered expression in peripheral blood at distinct stages of MS compared with the healthy population. The frequency of dysregulation was significantly higher than expected in CIS and progressive forms of MS. Pathway analysis for each MS stage–specific gene list showed that dysregulated genes contributed to pathogenic processes with scientific evidence in MS. CONCLUSIONS: Systematic gene expression analysis in PBMCs highlighted selective dysregulation of MS susceptibility genes playing a role in novel and well-known pathogenic pathways