288 research outputs found

    Bloch's theorem in orbital-density-dependent functionals: Band structures from Koopmans spectral functionals

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    Koopmans-compliant functionals provide an orbital-density-dependent framework for an accurate evaluation of spectral properties; they are obtained by imposing a generalized piecewise-linearity condition on the total energy of the system with respect to the occupation of any orbital. In crystalline materials, due to the orbital-density-dependent nature of the functionals, minimization of the total energy to a ground state provides a set of minimizing variational orbitals that are localized and thus break the periodicity of the underlying lattice. Despite this, we show that Bloch symmetry can be preserved and it is possible to describe the electronic states with a band-structure picture, thanks to the Wannier-like character of the variational orbitals. We also present a method to unfold and interpolate the electronic bands from supercell (Γ\Gamma-point) calculations, which enables us to calculate full band structures with Koopmans-compliant functionals. The results obtained for a set of benchmark semiconductors and insulators show very good agreement with state-of-the-art many-body perturbation theory and experiments, underscoring the reliability of these spectral functionals in predicting band structures.Comment: 34 pages, 4 figure

    Small relative age effect appears in professional female italian team sports

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    : The relative age effect (RAE) concerns those (dis)advantages and outcomes resulting from an interaction between the dates of selection and birthdates. Although this phenomenon is well known in a male context, limited data are available in female sports. Thus, the aim of this study was to quantify the prevalence and magnitude of the RAE in a female Italian context at the professional level in basketball, soccer, and volleyball. A total of 1535 birthdates of elite senior players were analyzed overall and separately between early and late career stages. Chi-square goodness-of-fit tests were applied to investigate the RAE in each sport. An asymmetry in birthdates was observed in all sports (Crammer's V ranged = 0.10-0.12). Players born close to the beginning of the year were 1.62 and 1.61 times more likely to reach first and second Italian divisions of soccer and volleyball, respectively, than those born in the last part of the year. A small over-representation of female athletes born close to the beginning of the year is evident at the senior professional level in all Italian investigated team sports. In soccer, this trend was more evident in the first stage of a senior career

    Benefits on coronary restenosis from elective paclitaxel-eluting stent implantation in patients aged 75 years and older

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    OBJECTIVE: Elderly patients are increasingly referred for revascularisation yet have been underrepresented in some large clinical trials. Although the advent of drug-eluting stents has dramatically reduced clinical events related to restenosis, older age remains one of the most important correlates of adverse outcome, even after an elective percutaneous coronary intervention (PCI). We sought to evaluate the impact of paclitaxel-eluting stents on coronary restenosis in elderly patients undergoing elective PCI. METHODS: Patients undergoing successful elective PCI with stenting of de novo coronary artery lesions were identified and screened for participation in this study. All patients included in our analysis were divided into two cohort groups: patients aged or=75 years (elderly cohort). We evaluated the six-month incidence of target lesion revascularisation (TLR) and major adverse cardiac events, which included TLR, death and myocardial infarction. RESULTS: A total of 171 (58 aged >or=75 years) consecutive patients were enrolled in the study. At six months, TLR rate was similar in both groups [1.77 vs. 1.72%, odds ratio (OR) 0.97, 95% confidence interval (CI) 0.08-10.9, P = 0.98, in the younger and elderly group, respectively]. Even the rate of major adverse cardiac events was comparable between the two groups (7.96 vs. 8.62%, OR 1.09, 95% CI 0.34-3.41, P = 0.88, in the younger and elderly group, respectively). Also the angiographic restenosis rates were comparable between patients or=75 years (4.42 vs. 3.46%, P = 0.76). CONCLUSIONS: After elective paclitaxel-eluting stent implantation, there is no difference in coronary restenosis in younger and elderly patients, suggesting an age-independent efficacy

    Early diagnosis of candidemia in intensive care unit patients with sepsis: a prospective comparison of (1→3)-β-D-glucan assay, Candida score, and colonization index

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    The culture-independent serum (1\u21923)-\u3b2-D-glucan (BG) detection test may allow early diagnosis of invasive fungal disease, but its clinical usefulness needs to be firmly established. A prospective single-center observational study was conducted to compare the diagnostic value of BG assay, Candida score (CS), and colonization index in intensive care unit (ICU) patients at risk for Candida sepsis

    koopmans: an open-source package for accurately and efficiently predicting spectral properties with Koopmans functionals

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    Over the past decade we have developed Koopmans functionals, a computationally efficient approach for predicting spectral properties with an orbital-density-dependent functional formulation. These functionals address two fundamental issues with density functional theory (DFT). First, while Kohn-Sham eigenvalues can loosely mirror experimental quasiparticle energies, they are not meant to reproduce excitation energies and there is formally no connection between the two (except for the HOMO for the exact functional). Second, (semi-)local DFT deviates from the expected piecewise linear behavior of the energy as a function of the total number of electrons. This can make eigenvalues an even poorer proxy for quasiparticle energies and, together with the absence of the exchange-correlation derivative discontinuity, contributes to DFT's underestimation of band gaps. By enforcing a generalized piecewise linearity condition to the entire electronic manifold, Koopmans functionals yield molecular orbital energies and solid-state band structures with comparable accuracy to many-body perturbation theory but at greatly reduced computational cost and preserving a functional formulation. This paper introduces "koopmans", an open-source package that contains all of the code and workflows needed to perform Koopmans functional calculations without requiring expert knowledge. The theory and algorithms behind Koopmans functionals are summarized, and it is shown how one can easily use the koopmans package to obtain reliable spectral properties of molecules and materials.Comment: 60 pages, 5 figures, 2 tables. Document includes supporting informatio

    Comparison between balloon angioplasty and additional coronary stent implantation for the treatment of drug-eluting stent restenosis: 18-month clinical outcomes

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    OBJECTIVE: To evaluate the long-term outcomes after different modalities of treatment of drug-eluting stent (DES) in-stent restenosis (ISR) in a 'real world' setting. METHODS: Actually, few and conflicting data are available about the management of in-stent restenosis (ISR) after DES implantation. In our 'real world' registry 1082 consecutive patients who received a DES implantation were included. At 9-month angiographic follow-up, 93 patients presented a DES ISR that was treated with 'homo-DES' (HMD) (N = 27), 'hetero-DES' (HTD) (N = 19) and conventional balloon angioplasty (POBA) (N = 47). We evaluated the clinical outcomes in terms of major adverse cardiac event (MACE) (death, myocardial infarction and target vessel revascularization) at 18 months. RESULTS: There was no difference for clinical and angiographic characteristics between the three groups, except for the presence of silent ischaemia as clinical presentation (7.7 HMD vs. 2.2% POBA; P = 0.0001). No late stent thrombosis was found. At 18-month clinical follow-up patients treated with HMD, HTD and POBA presented a rate of MACE of 10.2, 0 and 8.7%, respectively (P = NS). Kaplan-Meier survival probability showed that HTD and POBA treatment tended to have more favourable outcomes at 18 months than the HMD treatment. CONCLUSION: In our registry, POBA seems to be as effective as other DES implantations in cases of DES ISR, especially in cases of focal type (Mehran classification IA, IC), in terms of long-term outcomes

    The cut-off value for classifying active Italian children using the corresponding national version of the physical activity questionnaire

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    The present study aimed to determine a cut-off value following the filling in of a questionnaire (PAQ-C-It) to identify active Italian children. One-hundred-twenty-nine primary school children (5 Piedmont schools; 47.3% female; mean age = 10 ± 1 years) wore an accelerometer (Actigraph wGT3X-BT) to objectively quantify individual moderate-to-vigorous physical activity during one week. Afterwards, the PAQ-C-It was filled in by participants. A ROC curve procedure was applied to obtain an active/non-active cut-off point. Spearman's correlation coefficient was also applied to establish the relationship between the two parameters. According to the ROC analysis, the PAQ-C-It cut-off point value is identifiable at >2.75 to indicate active children (area under the curve = 0.62; standard error = 0.05; p = 0.025; coefficient intervals = 0.518-0.716; sensitivity = 0.592, specificity = 0.382), determining that 65 participants (55%) were non-active (mean PAQ-C-It value = 2.3 ± 0.4; active mean PAQ-C-It value = 3.3 ± 0.4). Spearman's correlation coefficient results were significant but with a small effect size (rho = 0.214; p = 0.008). In conclusion, the present results suggest that the PAQ-C-It can be cautiously used as tool to practically classify active Italian children because of a non-solid relationship between respective accelerometer data and MVPA daily data

    Do Italian consumers value health claims on extra-virgin olive oil?

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    The present study aims to extend the existing literature on EVOO consumers by assessing the importance of health claims in selecting EVOO products by jointly accounting for consumer preferences for the many search, experience, and credence attributes potentially available on EVOO, as well as by accounting for attitudinal and psychographic individual characteristics which affect consumer decision to prefer products with health claims over conventional ones (i.e. subjective nutritional knowledge, nutritional knowledge, nutritional importance, attitudes towards using food as a medicine, general health interest). The latter characteristics play a pivotal role in individual decisions to consider health claims when purchasing food, as indicated in the general literature on consumers and health claims. Such individual related characteristics capture the individual attitude and interest in preventing health losses through food choices and diet (see for instance, Roininen et al. (1999), Van Trijp & Van der Lans (2007) Dean et al. (2012)). To achieve our research goal, we employed a best-worst (BW) approach on a representative sample of Italian household members who are responsible for food shopping. Consumers tested competitively the multiple product attributes of EVOO. The share of consumers interested in health claims was detected by a latent class clustering model and characterized based on their socio-demographic, attitudinal, and psychographic features. Thus, this is the first study attempting to identify the features of consumers interested in health claims while purchasing EVOO using a large sample of household responsible of food purchases

    Novel human anti-claudin 1 mAbs inhibit hepatitis C virus infection and may synergize with anti-SRB1 mAb

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    Hepatitis C virus (HCV) is a major cause of chronic hepatitis and liver carcinoma and new therapies based on novel targets are needed. The tight junction protein claudin 1 (CLDN-1) is essential for HCV cell entry and spread, and anti-CLDN-1 rat and mouse mAbs are safe and effective in preventing and treating HCV infection in a human liver chimeric mouse model. To accelerate translation of these observations into a novel approach to treat HCV infection and disease in humans, we screened a phage display library of human single-chain antibody fragments by using a panel of CLDN-1-positive and -negative cell lines and identified phage specifically binding to CLDN-1. The 12 clones showing the highest levels of binding were converted into human IgG4. Some of these mAbs displayed low-nanomolar affinity, and inhibited infection of human hepatoma Huh7.5 cells by different HCV isolates in a dose-dependent manner. Cross-competition experiments identified six inhibitory mAbs that recognized distinct epitopes. Combination of the human anti-SRB1 mAb C-1671 with these anti-CLDN-1 mAbs could either increase or reduce inhibition of cell culture-derived HCV infection in vitro. These novel human anti-CLDN-1 mAbs are potentially useful to develop a new strategy for anti-HCV therapy and lend support to the combined use of antibodies targeting the HCV receptors CLDN-1 and SRB1, but indicate that care must be taken in selecting the proper combination
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