347 research outputs found

    Lorentz shift measurements in heavily irradiated silicon detectors in high magnetic fields

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    An external magnetic field exerts a Lorentz force on drifting electric charges inside a silicon strip sensor and thus shifts the cluster position of the collected charge. The shift can be related to the Lorentz angle which is typically a few degrees for holes and a few tens of degrees for electrons in a 4 T magnetic field. The Lorentz angle depends upon magnetic field, electric field inside the sensor and temperature. In this study the sensitivity to radiation for fluences up to 10^16 n/cm^2 has been studied. The Lorentz shift has been measured by inducing ionization with 670 nm red or 1070 nm infrared laser beams injected into the back side of the irradiated silicon sensor operated in magnetic fields up to 8 T. For holes the shift as a function of radiation is increasing, while for electrons it is decreasing and even changes sign. The fact that for irradiated sensors the Lorentz shift for electrons is smaller than for holes, in contrast to the observations in non-irradiated sensors, can be qualitatively explained by the structure of the electric field in irradiated sensors.Comment: Accepted publication for RD09 conference in Proceedings of Scienc

    Proceedings of the 3rd International Workshop on Formal Aspects in Security and Trust (FAST2005)

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    The present report contains the pre-proceedings of the third international Workshop on Formal Aspects in Security and Trust (FAST2005), held in Newcastle upon Tyne, 18-19 July 2005. FAST is an event affliated with the Formal Methods 2005 Congress (FM05). The third international Workshop on Formal Aspects in Security and Trust (FAST2005) aims at continuing the successful effort of the previous two FAST workshop editions for fostering the cooperation among researchers in the areas of security and trust. The new challenges offered by the so-called ambient intelligence space, as a future paradigm in the information society, demand for a coherent and rigorous framework of concepts, tools and methodologies to provide user\u27s trust&confidence on the underlying communication/interaction infrastructure. It is necessary to address issues relating to both guaranteeing security of the infrastructure and the perception of the infrastructure being secure. In addition, user confidence on what is happening must be enhanced by developing trust models effective but also easily comprehensible and manageable by users

    From Double-Pancake Coils to a Layer Wound 5 T REBCO-HTS High Field Insert Coil Design

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    A U-HPLC-ESI-MS/MS-based stable isotope dilution method for the detection and quantitation of methotrexate in plasma

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    INTRODUCTION: High-dose methotrexate (MTX) is used in the treatment of proliferative diseases such as acute lymphoblastic leukemia. Therapeutic drug monitoring of plasma MTX is important to monitor efficacy and adverse events. The authors aimed to develop a liquid chromatography, electrospray ionization, tandem mass spectrometry (LC-ESI-MS/MS)-based method to determine MTX in plasma for therapeutic drug monitoring and pharmacokinetic studies. METHODS: Samples were analyzed using a Waters Acquity UPLC and Quattro Premier XE. A Waters Acquity UPLC BEH C18 column (2.1 mm x 100 mm, 1.7 ÎŒm) was used running an isocratic mobile phase of 21% methanol and 10 mM ammonium bicarbonate. The electrospray was operated in the positive ionization mode monitoring the following mass transitions: m/z 455.2 > 308.2 for MTX and m/z 458.2 > 311.2 for MTXd3. The analysis combined straightforward sample preparation, consisting of dilution and protein precipitation, with a 3-minute run time. RESULTS: The method was linear up to 50 ÎŒM (r > 0.99), and the coefficient of variation was 1:10, was 5 nM. Method comparison with the Abbott TDx fluorescent polarization immunoassay (FPIA) showed excellent agreement, and a small but significant negative constant bias was detected (LC-MS/MS = 0.98 x FPIA - 7.3). CONLUSIONS: The authors developed a specific and sensitive stable isotope dilution LC-ESI-MS/MS method to monitor MTX concentrations in plasma within the clinically relevant range. The method can be easily applied in clinical laboratories because it combines straightforward sample pretreatment with LC-MS/MS. Copyrigh

    A New Immortalized Human Alveolar Epithelial Cell Model to Study Lung Injury and Toxicity on a Breathing Lung-On-Chip System

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    The evaluation of inhalation toxicity, drug safety and efficacy assessment, as well as the investigation of complex disease pathomechanisms, are increasingly relying on in vitro lung models. This is due to the progressive shift towards human-based systems for more predictive and translational research. While several cellular models are currently available for the upper airways, modelling the distal alveolar region poses several constraints that make the standardization of reliable alveolar in vitro models relatively difficult. In this work, we present a new and reproducible alveolar in vitro model, that combines a human derived immortalized alveolar epithelial cell line ((AX)iAEC) and organ-on-chip technology mimicking the lung alveolar biophysical environment ((AX)lung-on-chip). The latter mimics key features of the in vivo alveolar milieu: breathing-like 3D cyclic stretch (10% linear strain, 0.2 Hz frequency) and an ultrathin, porous and elastic membrane. (AX)iAECs cultured on-chip were characterized for their alveolar epithelial cell markers by gene and protein expression. Cell barrier properties were examined by TER (Transbarrier Electrical Resistance) measurement and tight junction formation. To establish a physiological model for the distal lung, (AX)iAECs were cultured for long-term at air-liquid interface (ALI) on-chip. To this end, different stages of alveolar damage including inflammation (via exposure to bacterial lipopolysaccharide) and the response to a profibrotic mediator (via exposure to Transforming growth factor ÎČ1) were analyzed. In addition, the expression of relevant host cell factors involved in SARS-CoV-2 infection was investigated to evaluate its potential application for COVID-19 studies. This study shows that (AX)iAECs cultured on the (AX)lung-on-chip exhibit an enhanced in vivo-like alveolar character which is reflected into: 1) Alveolar type 1 (AT1) and 2 (AT2) cell specific phenotypes, 2) tight barrier formation (with TER above 1,000 Ω cm(2)) and 3) reproducible long-term preservation of alveolar characteristics in nearly physiological conditions (co-culture, breathing, ALI). To the best of our knowledge, this is the first time that a primary derived alveolar epithelial cell line on-chip representing both AT1 and AT2 characteristics is reported. This distal lung model thereby represents a valuable in vitro tool to study inhalation toxicity, test safety and efficacy of drug compounds and characterization of xenobiotics

    The prevalence, correlation, and co-occurrence of neuropathology in old age: harmonisation of 12 measures across six community-based autopsy studies of dementia

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    Background: Population-based autopsy studies provide valuable insights into the causes of dementia but are limited by sample size and restriction to specific populations. Harmonisation across studies increases statistical power and allows meaningful comparisons between studies. We aimed to harmonise neuropathology measures across studies and assess the prevalence, correlation, and co-occurrence of neuropathologies in the ageing population. Methods: We combined data from six community-based autopsy cohorts in the US and the UK in a coordinated cross-sectional analysis. Among all decedents aged 80 years or older, we assessed 12 neuropathologies known to be associated with dementia: arteriolosclerosis, atherosclerosis, macroinfarcts, microinfarcts, lacunes, cerebral amyloid angiopathy, Braak neurofibrillary tangle stage, Consortium to Establish a Registry for Alzheimer's disease (CERAD) diffuse plaque score, CERAD neuritic plaque score, hippocampal sclerosis, limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC), and Lewy body pathology. We divided measures into three groups describing level of confidence (low, moderate, and high) in harmonisation. We described the prevalence, correlations, and co-occurrence of neuropathologies. Findings: The cohorts included 4354 decedents aged 80 years or older with autopsy data. All cohorts included more women than men, with the exception of one study that only included men, and all cohorts included decedents at older ages (range of mean age at death across cohorts 88·0–91·6 years). Measures of Alzheimer's disease neuropathological change, Braak stage and CERAD scores, were in the high confidence category, whereas measures of vascular neuropathologies were in the low (arterioloscerosis, atherosclerosis, cerebral amyloid angiopathy, and lacunes) or moderate (macroinfarcts and microinfarcts) categories. Neuropathology prevalence and co-occurrence was high (2443 [91%] of 2695 participants had more than one of six key neuropathologies and 1106 [41%] of 2695 had three or more). Co-occurrence was strongly but not deterministically associated with dementia status. Vascular and Alzheimer's disease features clustered separately in correlation analyses, and LATE-NC had moderate associations with Alzheimer's disease measures (eg, Braak stage ρ=0·31 [95% CI 0·20–0·42]). Interpretation: Higher variability and more inconsistency in the measurement of vascular neuropathologies compared with the measurement of Alzheimer's disease neuropathological change suggests the development of new frameworks for the measurement of vascular neuropathologies might be helpful. Results highlight the complexity and multi-morbidity of the brain pathologies that underlie dementia in older adults and suggest that prevention efforts and treatments should be multifaceted. Funding: Gates Ventures

    A Family-Wide RT-PCR Assay for Detection of Paramyxoviruses and Application to a Large-Scale Surveillance Study

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    Family-wide molecular diagnostic assays are valuable tools for initial identification of viruses during outbreaks and to limit costs of surveillance studies. Recent discoveries of paramyxoviruses have called for such assay that is able to detect all known and unknown paramyxoviruses in one round of PCR amplification. We have developed a RT-PCR assay consisting of a single degenerate primer set, able to detect all members of the Paramyxoviridae family including all virus genera within the subfamilies Paramyxovirinae and Pneumovirinae. Primers anneal to domain III of the polymerase gene, with the 3â€Č end of the reverse primer annealing to the conserved motif GDNQ, which is proposed to be the active site for nucleotide polymerization. The assay was fully optimized and was shown to indeed detect all available paramyxoviruses tested. Clinical specimens from hospitalized patients that tested positive for known paramyxoviruses in conventional assays were also detected with the novel family-wide test. A high-throughput fluorescence-based RT-PCR version of the assay was developed for screening large numbers of specimens. A large number of samples collected from wild birds was tested, resulting in the detection of avian paramyxoviruses type 1 in both barnacle and white-fronted geese, and type 8 in barnacle geese. Avian metapneumovirus type C was found for the first time in Europe in mallards, greylag geese and common gulls. The single round family-wide RT-PCR assay described here is a useful tool for the detection of known and unknown paramyxoviruses, and screening of large sample collections from humans and animals

    Making sense of big data in health research: Towards an EU action plan.

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    Medicine and healthcare are undergoing profound changes. Whole-genome sequencing and high-resolution imaging technologies are key drivers of this rapid and crucial transformation. Technological innovation combined with automation and miniaturization has triggered an explosion in data production that will soon reach exabyte proportions. How are we going to deal with this exponential increase in data production? The potential of "big data" for improving health is enormous but, at the same time, we face a wide range of challenges to overcome urgently. Europe is very proud of its cultural diversity; however, exploitation of the data made available through advances in genomic medicine, imaging, and a wide range of mobile health applications or connected devices is hampered by numerous historical, technical, legal, and political barriers. European health systems and databases are diverse and fragmented. There is a lack of harmonization of data formats, processing, analysis, and data transfer, which leads to incompatibilities and lost opportunities. Legal frameworks for data sharing are evolving. Clinicians, researchers, and citizens need improved methods, tools, and training to generate, analyze, and query data effectively. Addressing these barriers will contribute to creating the European Single Market for health, which will improve health and healthcare for all Europeans
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