736 research outputs found

    Trapped ion mobility spectrometry and PASEF enable in-depth lipidomics from minimal sample amounts

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    A comprehensive characterization of the lipidome from limited starting material remains very challenging. Here we report a high-sensitivity lipidomics workflow based on nanoflow liquid chromatography and trapped ion mobility spectrometry (TIMS). Taking advantage of parallel accumulation-serial fragmentation (PASEF), we fragment on average 15 precursors in each of 100 ms TIMS scans, while maintaining the full mobility resolution of co-eluting isomers. The acquisition speed of over 100 Hz allows us to obtain MS/MS spectra of the vast majority of isotope patterns. Analyzing 1 mu L of human plasma, PASEF increases the number of identified lipids more than three times over standard TIMS-MS/MS, achieving attomole sensitivity. Building on high intra- and inter-laboratory precision and accuracy of TIMS collisional cross sections (CCS), we compile 1856 lipid CCS values from plasma, liver and cancer cells. Our study establishes PASEF in lipid analysis and paves the way for sensitive, ion mobility-enhanced lipidomics in four dimensions

    ''Amis du monde'' : un projet collaboratif

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    Notre proposition d’intervention a comme but de montrer et de faire connaĂźtre un projet collaboratif dont les acteurs principaux ont Ă©tĂ© des Ă©tudiants du Centre d’Enseignement de Langues ÉtrangĂšres – Didaskaleio – de l’UniversitĂ© nationale et capodistrienne d’AthĂšnes. Ce projet a Ă©tĂ© rĂ©alisĂ© dans le but de participer au Concours « Amis du Monde » organisĂ© par l’APF-fu (GrĂšce) et la Commission de l’Europe de l’Ouest (CEO) pendant l’annĂ©e universitaire 2015-2016. La production conçue et rĂ©alisĂ©e par les Ă©tudiant-e-s s’inscrit dans le cadre de la perspective actionnelle («  je prĂ©fĂšre personnellement “perspective actionnelle” Ă  “approche actionnelle” », Puren, 2011 : 7) et de l’enseignement collaboratif Ă  des fins Ă©ducatives ; l’apprentissage de la langue française Ă  travers la mise en prioritĂ© des objectifs communicatifs et socio-humanistes ; ces derniers renvoyant aux approches plurielles en classe de langue et Ă  l’interculturalitĂ©. Le projet « Amis du Monde » a Ă©tĂ© l’opportunitĂ© pour les Ă©tudiante-s de se sensibiliser en ce qui concerne les rĂ©fugiĂ©s qui ont quittĂ© la Syrie et qui sont arrivĂ©s en GrĂšce, il y a sept mois. Ainsi, ils ont donnĂ© naissance Ă  une Ɠuvre, en langue française, aprĂšs avoir suivi toute une dĂ©marche de collecte de matĂ©riel, de recherche bibliographique ainsi que de conception sur le contenu de la production-vidĂ©o. La participation des Ă©tudiant-e-s au concours, a contribuĂ© au renforcement de l’esprit d’équipe tant des Ă©tudiants que des enseignants, Ă  la collaboration entre les enseignants et les Ă©tudiants afin de crĂ©er un produit en langue cible ainsi qu’à l’autonomie de l’apprenant en langue Ă©trangĂšre. À part l’actualitĂ© qui a beaucoup motivĂ© les Ă©tudiants Ă  s’occuper de ce projet, ce sont aussi les enseignants qui les ont conduits Ă  la signature d’un contrat pĂ©dagogique – de façon implicite – qui mettait en valeur des objectifs sociaux, communicatifs toujours caractĂ©risĂ©s de ce qui nous semble ĂȘtre indispensable en pĂ©dagogie et en classe de langue, c’est-Ă -dire d’une certaine humanitĂ© qui met au centre de l’action l’ĂȘtre humain et qui contribue Ă  la connaissance de l’Autre. Par cette prĂ©sentation, nous voulons partager avec vous tant des tĂ©moignages des Ă©tudiant-e-s que leur production, mais nous avons aussi le but de montrer en dĂ©tail l’approche humaniste qui a Ă©tĂ© suivie pour l’accomplissement de ce projet collaboratif par un public adulte, universitaire

    312 MAX Phases: Elastic Properties and Lithiation

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    Interest in the Mn+1AXn phases (M = early transition metal; A = group 13–16 elements, and X = C or N) is driven by their ceramic and metallic properties, which make them attractive candidates for numerous applications. In the present study, we use the density functional theory to calculate the elastic properties and the incorporation of lithium atoms in the 312 MAX phases. It is shown that the energy to incorporate one Li atom in Mo3SiC2, Hf3AlC2, Zr3AlC2, and Zr3SiC2 is particularly low, and thus, theoretically, these materials should be considered for battery applications

    Intrinsic Defects and H Doping in WO3.

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    WO3 is widely used as industrial catalyst. Intrinsic and/or extrinsic defects can tune the electronic properties and extend applications to gas sensors and optoelectonics. However, H doping is a challenge to WO3, the relevant mechanisms being hardly understood. In this context, we investigate intrinsic defects and H doping by density functional theory and experiments. Formation energies are calculated to determine the lowest energy defect states. O vacancies turn out to be stable in O-poor environment, in agreement with X-ray photoelectron spectroscopy, and O-H bond formation of H interstitial defects is predicted and confirmed by Fourier transform infrared spectroscopy

    Diagnostic Clinical and Laboratory Findings in Response to Predetermining Bacterial Pathogen: Data from the Meningitis Registry

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    BACKGROUND: Childhood meningitis continues to be an important cause of mortality in many countries. The search for rapid diagnosis of acute bacterial meningitis has lead to the further exploration of prognostic factors. This study was scheduled in an attempt to analyze various clinical symptoms as well as rapid laboratory results and provide an algorithm for the prediction of specific bacterial aetiology of childhood bacterial meningitis. METHODOLOGY AND PRINCIPAL FINDINGS: During the 32 year period, 2477 cases of probable bacterial meningitis (BM) were collected from the Meningitis Registry (MR). Analysis was performed on a total of 1331 confirmed bacterial meningitis cases of patients aged 1 month to 14 years. Data was analysed using EPI INFO (version 3.4.3-CDC-Atlanta) and SPSS (version 15.0-Chicago) software. Statistically significant (p<0.05) variables were included in a conditional backward logistic regression model. A total of 838 (63.0%) attributed to Neisseria meningitidis, 252 (18.9%) to Haemophilus influenzae, 186 (14.0%) to Streptococcus pneumoniae and 55 (4.1%) due to other bacteria. For the diagnosis of Meningococcal Meningitis, the most significant group of diagnostic criteria identified included haemorrhagic rash (OR 22.36), absence of seizures (OR 2.51), headache (OR 1.83) and negative gram stain result (OR 1.55) with a Positive Predictive Value (PPV) of 96.4% (95%CI 87.7-99.6). For the diagnosis of Streptococcus pneumoniae, the most significant group of diagnostic criteria identified included absence of haemorrhagic rash (OR 13.62), positive gram stain (OR 2.10), coma (OR 3.11), seizures (OR 3.81) and peripheral WBC > or = 15000/microL (OR 2.19) with a PPV of 77.8% (95%CI 40.0-97.2). For the diagnosis of Haemophilus influenzae, the most significant group of diagnostic criteria included, absence of haemorrhagic rash (OR 13.61), age > or = 1 year (OR 2.04), absence of headache (OR 3.01), CSF Glu < 40 mg/dL (OR 3.62) and peripheral WBC < 15,000/microL (OR 1.74) with a PPV of 58.5% (95%CI 42.1-73.7). CONCLUSIONS: The use of clinical and laboratory predictors for the assessment of the causative bacterial pathogen rather than just for predicting outcome of mortality seems to be a useful tool in the clinical management and specific treatment of BM. These findings should be further explored and studied

    The party politics of Euroscepticism in times of crisis: the case of Greece

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    This article traces the trajectory of party Euroscepticism in Greece drawing upon theories of issue competition. It demonstrates that the economic dimension of the multiple crises facing the EU contributed to a Eurosceptic shift in public opinion; the electoral success of Eurosceptic parties; new parties populating the Europhile end of the spectrum; and the formation of a coalition government united not by ideological affinity but by a common Eurosceptic and anti-austerity agenda. Mainstream parties maintained their pro-EU agendas and challenger parties offered both pro- and anti-EU policy options to the electorate. The prospect of power resulted in the progressive softening of Euroscepticism among challenger parties. EU issue salience was relatively high across the party system and remained so during the crisis. Although Greek parties justified their pro- and anti-EU attitudes using a number of frames, economic arguments were prevalent at the height of the crisis, and challenger parties of the left intensified their claims of the EU interfering in national politics. The findings have implications for our understanding of the evolving nature of Euroscepticism and the ways in which it may feature in domestic party politics

    Efficient and stable air-processed ternary organic solar cells incorporating gallium-porphyrin as electron cascade material

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    Two gallium porphyrins, a tetraphenyl GaCl porphyrin, termed as (TPP)GaCl, and an octaethylporphyrin GaCl porphyrin, termed as (OEP)GaCl, were synthesized to use as an electron cascade in ternary organic bulk heterojunction films. A perfect matching of both gallium porphyrins’ energy levels with that of poly(3-hexylthiophene-2,5-diyl) (P3HT) or poly[N-9â€Č-heptadecanyl-2,7-carbazole-alt-5,5-(4â€Č,7â€Č-di-2-thienyl-2â€Č,1â€Č,3â€Č-benzothiadiazole)] (PCDTBT) polymer donor and the 6,6-phenyl C71 butyric acid methyl ester (PCBM) fullerene acceptor, forming an efficient cascade system that could facilitate electron transfer between donor and acceptor, was demonstrated. Therefore, ternary organic solar cells (OSCs) using the two porphyrins in various concentrations were fabricated where a performance enhancement was obtained. In particular, (TPP)GaCl-based ternary OSCs of low concentration (1:0.05 vv%) exhibited a ~17% increase in the power conversion efficiency (PCE) compared with the binary device due to improved exciton dissociation, electron transport and reduced recombination. On the other hand, ternary OSCs with a high concentration of (TPP)GaCl (1:0.1 vv%) and (OEP)GaCl (1:0.05 and 1:0.1 vv%) showed the poorest efficiencies due to very rough nanomorphology and suppressed crystallinity of ternary films when the GaCl porphyrin was introduced to the blend, as revealed from X-ray diffraction (XRD) and atomic force microscopy (AFM). The best performing devices also exhibited improved photostability when exposed to sunlight illumination for a period of 8 h than the binary OSCs, attributed to the suppressed photodegradation of the ternary (TPP)GaCl 1:0.05-based photoactive film

    Optimization of the hydrogen response characteristics of halogen-doped SnO2

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    The increasing demand for efficient sensing devices with facile low-cost fabrication has attracted a lot of scientific research effort in the recent years. In particular, the scientific community aims to develop new candidate materials suitable for energy-related devices, such as sensors and photovoltaics or clean energy applications such as hydrogen production. One of the most prominent methods to improve materials functionality and performance is doping key device component(s). This paper aims to examine in detail, both from a theoretical and an experimental point of view, the effect of halogen doping on the properties of tin dioxide (SnO2) and provide a deeper understanding on the atomic scale mechanisms with respect to their potential applications in sensors. Density Functional Theory (DFT) calculations are used to examine the defect processes, the electronic structure and the thermodynamical properties of halogen-doped SnO2. Calculations show that halogen doping reduces the oxide bandgap by creating gap states which agree well with our experimental data. The crystallinity and morphology of the samples is also altered. The synergy of these effects results in a significant improvement of the gas-sensing response. This work demonstrates for the first time a complete theoretical and experimental characterization of halogen-doped SnO2 and investigates the possible responsible mechanisms. Our results illustrate that halogen doping is a low-cost method that significantly enhances the room temperature response of SnO2
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