3,057 research outputs found

    Effect of a skin-deep surface zone on formation of two-dimensional electron gas at a semiconductor surface

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    Two dimensional electron gases (2DEGs) at surfaces and interfaces of semiconductors are described straightforwardly with a 1D self-consistent Poisson-Schr\"{o}dinger scheme. However, their band energies have not been modeled correctly in this way. Using angle-resolved photoelectron spectroscopy we study the band structures of 2DEGs formed at sulfur-passivated surfaces of InAs(001) as a model system. Electronic properties of these surfaces are tuned by changing the S coverage, while keeping a high-quality interface, free of defects and with a constant doping density. In contrast to earlier studies we show that the Poisson-Schr\"{o}dinger scheme predicts the 2DEG bands energies correctly but it is indispensable to take into account the existence of the physical surface. The surface substantially influences the band energies beyond simple electrostatics, by setting nontrivial boundary conditions for 2DEG wavefunctions.Comment: 9 pages, 7 figures, 2 table

    Anomaly Detection in VoIP Traffic with Trends

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    In this paper we present methodological advances in anomaly detection, which, among other purposes, can be used to discover abnormal traffic patterns under the presence of deterministic trends in data, given that specific assumptions about the traffic type and nature are met. A performance study of the proposed methods, both if these assumptions are fulfilled and violated, shows good results in great generality. Our study features VoIP call counts, but the methodology can be applied to any data following, at least roughly, a non-homogeneous Poisson process (think of highly aggregated traffic flows)

    Altered Connexin 43 Expression Underlies Age-Dependent Decrease of Regulatory T Cell Suppressor Function in Nonobese Diabetic Mice

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    Type 1 diabetes is one of the most extensively studied autoimmune diseases, but the cellular and molecular mechanisms leading to T cell–mediated destruction of insulin-producing β cells are still not well understood. In this study, we show that regulatory T cells (Tregs) in NOD mice undergo age-dependent loss of suppressor functions exacerbated by the decreased ability of activated effector T cells to upregulate Foxp3 and generate Tregs in the peripheral organs. This age-dependent loss is associated with reduced intercellular communication mediated by gap junctions, which is caused by impaired upregulation and decreased expression of connexin 43. Regulatory functions can be corrected, even in T cells isolated from aged, diabetic mice, by a synergistic activity of retinoic acid, TGF-β, and IL-2, which enhance connexin 43 and Foxp3 expression in Tregs and restore the ability of conventional CD4+ T cells to upregulate Foxp3 and generate peripherally derived Tregs. Moreover, we demonstrate that suppression mediated by Tregs from diabetic mice is enhanced by a novel reagent, which facilitates gap junction aggregation. In summary, our report identifies gap junction–mediated intercellular communication as an important component of the Treg suppression mechanism compromised in NOD mice and suggests how Treg mediated immune regulation can be improved

    Fruits of Hippophaë rhamnoides in human leukocytes and Caco-2 cell monolayer models—A question about their preventive role in lipopolysaccharide leakage and cytokine secretion in endotoxemia

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    Preparations from Hippophaë rhamnoides L. (sea buckthorn) have been traditionally used in the treatment of skin and digestive disorders, such as gastritis, gastric and duodenal ulcers, uterine erosions, as well as oral, rectal, and vaginal mucositis, in particular in the Himalayan and Eurasian regions. An influence of an aqueous extract from the fruits of H. rhamnoides (HR) on leakage of lipopolysaccharide (LPS) from Escherichia coli through gut epithelium developed from the human colorectal adenocarcinoma (Caco-2) monolayer in vitro and glucose transporter 2 (GLUT2) translocation were the principal objectives of the study. Additionally, the effect of HR on the production of pro- and anti-inflammatory cytokines (interleukins: IL-8, IL-1β, IL-10, IL-6; tumor necrosis factor: TNF-α) by the Caco-2 cell line, human neutrophils (PMN), and peripheral blood mononuclear cells (PBMC) was evaluated. The concentration of LPS on the apical and basolateral sides of the Caco-2 monolayer was evaluated with a Limulus Amebocyte Lysate (LAL) assay. GLUT2 translocation was evaluated using an immunostaining assay, whereas secretion of cytokines by cell cultures was established with an enzyme-linked immunosorbent (ELISA) assay. HR (500 μg/ml) significantly inhibited LPS leakage through epithelial monolayer in vitro in comparison with non-treated control. The treatment of Caco-2 cells with HR (50–100 μg/ml) showed GLUT2 expression similar to the non-treated control. HR decreased the secretion of most pro-inflammatory cytokines in all tested models. HR might prevent low-grade chronic inflammation caused by metabolic endotoxemia through the prevention of the absorption of LPS and decrease of chemotactic factors released by immune and epithelial cells, which support its use in metabolic disorders in traditional medicine

    Neural correlates of working memory and its association with metabolic parameters in early-treated adults with phenylketonuria.

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    BACKGROUND Phenylketonuria (PKU) is an inborn error of metabolism affecting the conversion of phenylalanine (Phe) into tyrosine. Previous research has found cognitive and functional brain alterations in individuals with PKU even if treated early. However, little is known about working memory processing and its association with task performance and metabolic parameters. The aim of the present study was to examine neural correlates of working memory and its association with metabolic parameters in early-treated adults with PKU. METHODS This cross-sectional study included 20 early-treated adults with PKU (mean age: 31.4 years ± 9.0) and 40 healthy controls with comparable age, sex, and education (mean age: 29.8 years ± 8.2). All participants underwent functional magnetic resonance imaging (fMRI) of working memory to evaluate the fronto-parietal working memory network. Fasting blood samples were collected from the individuals with PKU to acquire a concurrent plasma amino acid profile, and retrospective Phe concentrations were obtained to estimate an index of dietary control. RESULTS On a cognitive level, early-treated adults with PKU displayed significantly lower accuracy but comparable reaction time in the working memory task compared to the control group. Whole-brain analyses did not reveal differences in working memory-related neural activation between the groups. Exploratory region-of-interest (ROI) analyses indicated reduced neural activation in the left and right middle frontal gyri and the right superior frontal gyrus in the PKU group compared to the control group. However, none of the ROI analyses survived correction for multiple comparisons. Neural activation was related to concurrent Phe, tyrosine, and tryptophan concentrations but not to retrospective Phe concentrations. CONCLUSION In early-treated adults with PKU, cognitive performance and neural activation are slightly altered, a result that is partly related to metabolic parameters. This study offers a rare insight into the complex interplay between metabolic parameters, neural activation, and cognitive performance in a sample of individuals with PKU

    Contribution à l'implantation de la méthode Lean Six Sigma dans les Petites et Moyennes Entreprises pour l'amélioration des processus

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    A l image des grands groupes, les PME souhaitent, elles aussi, profiter des méthodes modernes de management pour améliorer leurs processus, leurs performances et leur compétitivité. L intérêt du secteur des PME se porte sur les éléments du concept Lean Six Sigma qui leur semblent appropriés pour réaliser ces objectifs. Après avoir constaté une lacune dans les recherches sur ce sujet et une lacune méthodologique concernant l implémentation du LSS dans les PME, nous proposons une méthodologie de conception, d application et de contrôle du LSS pour ces PME, que nous avons appelée LSS Plutus. Elle est dédiée aux PME de la production et elle prend en compte leur spécificité. Dans ce but, nous avons restreint la boîte à outils traditionnelle du LSS utilisée dans les grands groupes. Nous avons également créé deux variantes pour mettre en œuvre notre méthodologie qui correspondent aux besoins, capacités et maturités différents des PME. Nous avons élaboré des indicateurs, des outils, ainsi qu un guide d application de la méthode LSS pour les PME de la production et sa version informatique en TIBCO. Nous avons décidé de renforcer l efficience des améliorations, en déployant les actions de planification, de standardisation et de pérennisation des changements. Dans ce but, nous proposons de modifier les critères du Modèle d Excellence E.F.Q.M. pour qu elles puissent prendre en compte les conditions de fonctionnement de la méthode LSS dans les PME. La méthodologie proposée a été vérifiée dans deux PME de la production en Pologne et en France, ce qui a confirmé son utilité et son efficacité en termes d amélioration des performances et de développement des organisationsAs well as the large companies, also the small and medium-sized enterprises desire to take advantage of modern management methods to improve their process, their performances and competitiveness. The interest of the SMEs is focused on the elements of the Lean Six Sigma concept that seem to be appropriate to achieve these goals. As we have identified a gap in the research on this topic and a methodological gap about the LSS implementation in the small and medium companies, we propose a methodology that we called LSS Plutus to design, apply and control Lean Six Sigma in the SMEs. It is dedicated to the small and medium production enterprises and it takes into account their specificity. For this purpose, we have limited the traditional LSS toolbox used by the large companies. We have also created two variants to apply our methodology according to the different needs, capacities and maturities of the SMEs. We have developed indicators, tools, as well as a practical guide for applying the LSS for the production SMEs and its computerized version in TIBCO. To enhance the efficiency of the improvements, we have deployed the planning, standardization and sustainability of the changes. For this purpose, we propose to modify the criteria of the EFQM Excellence Model in order to adapt it to the operating conditions of the Lean Six Sigma method in the SMEs. The proposed methodology has been verified in two production SMEs in Poland and in France that confirmed its utility and effectiveness in terms of performance improvement and organizational developmentVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF

    Profiling of Phenolic Compounds and Antioxidant Activity of Dry Extracts from the Selected Sorbus Species

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    The antioxidant efficiency of dry extracts from inflorescences and/or leaves of seven Sorbus species was studied using four in vitro tests of SET (single electron transfer) and HAT-type (hydrogen atom transfer) mechanisms. The 70% methanol extracts and its diethyl ether, ethyl acetate, n-butanol and water fractions were tested in parallel with the phenolic standards, e.g., caffeic acid, quercetin, BHA, BHT, and TroloxÒ. The SET-type activity of the extracts depended primarily on the extraction solvent. The most valuable extracts were n-butanol and ethyl acetate ones, which activity was high in the DPPH (EC50 = 3.2–5.2 μg/mL), TEAC (2.8–4.0 mmol Trolox®/g), and FRAP (9.8–13.7 mmol Fe2+/g) tests, and strongly correlated with the total phenolic levels (39.6–58.2% of gallic acid equivalents). The HPLC-PDA analysis of the extracts led to the identification of chlorogenic acid, isoquercitrin, hyperoside, rutin, quercetin 3-O-sophoroside, and sexangularetin 3-O-b-D-glucopyranoside as the main components. Apart from flavonoids and hydroxycinnamic acids, proanthocyanidins have also a significant impact on the SET-type activity. The HAT-reactivity of the extracts in the linoleic acid peroxidation test (IC50 = 36.9–228.3 μg/mL) depended more strongly on the plant tissue than on the extraction solvent, and its correlation with the phenolic content was weak. Both SET and HAT-type activity of the most potent Sorbus extracts was comparable with the activity of the standards, indicating their great potential as effective sources for health products

    Patient factors associated with titration of medical therapy in patients with heart failure with reduced ejection fraction: data from the QUALIFY international registry

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    Aims: Failure to prescribe key medicines at evidence-based doses is associated with increased mortality and hospitalization forpatients with Heart Failure with reduced Ejection Fraction (HFrEF). We assessed titration patterns of guideline-recommendedHFrEF medicines internationally and explored associations with patient characteristics in the global, prospective, observational,longitudinal registry. Methods and results: Data were collected from September 2013 through December 2014, with 7095 patients from 36 coun-tries [>18 years, previous HF hospitalization within 1–15 months, left ventricular ejection fraction (LVEF)≤40%] enrolled, withdosage data at baseline and up to 18 months from 4368 patients. In 4368 patients (mean age 63 ± 17 years, 75% male)≥100%target doses at baseline: 30.6% (ACEIs), 2.9% (ARBs), 13.9% (BBs), 53.8% (MRAs), 26.2% (ivabradine). Atfinal follow-up,≥100%target doses achieved in more patients for ACEI (34.8%), BB (18.0%), and ivabradine (30.5%) but unchanged for ARBs (3.2%)and MRAs (53.7%). Adjusting for baseline dosage, uptitration during follow-up was more likely with younger age, highersystolic blood pressure, and in absence of chronic kidney disease or diabetes for ACEIs/ARBs; younger age, higher body massindex, higher heart rate, lower LVEF, and absence of coronary artery disease for BBs. For ivabradine, uptitration was morelikely with higher resting heart rate. Conclusions: The international QUALIFY Registry suggests that few patients with HFrEF achieve target doses ofdisease-modifying medication, especially older patients and those with co-morbidity. Quality improvement initiatives are ur-gently required

    Digitalization in Construction, Computer-based Design for Structural Elements, PArt 2: Analyses and Validation of Compliance to EuroCodes

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    A classic structural analysis is characterized by the usage of a wide spectrum of manual, specialized analysis methods. An engineer has to break down the complex problem into small manageable sub-problems. This procedure will be completely superseded by the advent of numerical methods. A full model of the spatial structure will be built up. A similar revolution has already begun by the introduction of finite shell and volume elements into commercially available FE software. The idea is that these models are closer to reality and allow us to capture both global and local effects in one single comprehensive model. This, however, introduces modelling questions and numerical effects, which are explicitly excluded from simplified theory, and questions arise regarding the trustworthiness of these results. Shell elements have already been fairly well established in practical engineering. The next step could be the use of volume elements to overcome certain restriction inherent in shell formulations. One driving force for this tendency is BIM (Building Information Modelling). Here the geometrical model is, like nature itself, fully 3D. It can be directly translated into the Finite Element Method (FEM). However, structural design in the 27 EU member states and 4 EFTA countries has to be performed according to the Eurocodes (EC), representing harmonized European Standards (EN) for the structural design. These design codes regulate essential requirements regarding mechanical resistance and stability as well as safety aspects. The current Eurocodes essentially stipulate engineering design models which can easily be transferred to classical structural analyses, but often do not give comprehensive references to the application and evaluation of advanced numerical simulations. The application of associated software products is not regulated by norms. This situation often results in discussions and different interpretations of the design results. Ultimately, false computational assumptions and misinterpretations can lead to damages and unsafe designs. Guidance for the verification of the software results is required and the link to the current and upcoming second generation of Eurocodes is also presented by the project. In parallel the possibilities by digitalization in construction by Building Information Modelling and the transfer of data from the architectural model to the structural model have been investigatedAugutst 202

    Contemporary management of octogenarians hospitalized for heart failure in Europe: Euro Heart Failure Survey II

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    Aims International guidelines are frequently not implemented in the elderly population with heart failure (HF). This study determined the management of octogenarians with HF enrolled in Euro Heart Failure Survey II (EHFS II) (2004-05). Methods and results We compared the clinical profile, 12 month outcomes, and management modalities between 741 octogenarians (median age 83.7 years) and 2836 younger patients (median age 68.4 years) hospitalized for acute/decompensated HF. Management modalities were also compared with those observed in EHFS I (2000-01). Female gender, new onset HF (de novo), hypertension, atrial fibrillation, co-morbidities, disabilities, and low quality of life were more common in the elderly (all P < 0.001). Mortality rates during hospital stay and during 12 months after discharge were increased in octogenarians (10.7 vs. 5.6% and 28.4 vs. 18.5%, P < 0.001). Underuse and underdosage of medications recommended for HF were observed in the elderly. However, a significant improvement was observed when compared with EHFS I both in the overall HF octogenarian population and in the subgroup with ejection fraction ≤45% for prescription rates of ACE-I/ARBs, beta-blockers, and aldosterone antagonists at discharge (82 vs. 71%; 56 vs. 29%; 54 vs. 18.5%, respectively, all P < 0.01), as well as for recommended combinations and dosage. Prescription rates remained stable for 12 months after discharge in survivors. Conclusion Our study confirms that the contemporary management of very elderly patients with HF remains suboptimal but that the situation is improvin
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