1,108 research outputs found

    High resolution shadow mask patterning in deep holes and its application to an electrical wafer feed-through

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    The paper presents a technique to pattern materials in deep holes and/or on non-planar substrate surfaces. A rather old technique, namely, electron-beam evaporation of metals through a shadow mask, is used. The realization of high-resolution shadow masks using micromachining techniques is described. Further, a low ohmic electrical wafer foed-through with a small parasitic capacitance to the substrate and a high placing density is presented

    Clinical implications of microvascular obstruction and intramyocardial haemorrhage in acute myocardial infarction using cardiovascular magnetic resonance imaging

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    OBJECTIVES: To investigate the clinical implications of microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH) in acute myocardial infarction (AMI). METHODS: Ninety patients with a first AMI undergoing primary percutaneous coronary intervention (PCI) were studied. T2-weighted, cine and late gadolinium-enhanced cardiovascular magnetic resonance imaging was performed at 5 ± 2 and 103 ± 11 days. Patients were categorised into three groups based on the presence or absence of MVO and IMH. RESULTS: MVO was observed in 54% and IMH in 43% of patients, and correlated significantly (r = 0.8, p < 0.001). Pre-PCI thrombolysis in myocardial infarction 3 flow was only observed in MVO(−)/IMH(−) patients. Infarct size and impairment of systolic function were largest in MVO(+)/IMH(+) patients (n = 39, 23 ± 9% and 47 ± 7%), smallest in MVO(−)/IMH(−) patients (n = 41, 8 ± 8% and 55 ± 8%) and intermediate in MVO(+)/IMH(−) patients (n = 10, 16 ± 7% and 51 ± 6%, p < 0.001). LVEF increased in all three subgroups at follow-up, but remained intermediate in MVO(+)/IMH(−) and was lowest in MVO(+)/IMH(+) patients. Using random intercept model analysis, only infarct size was an independent predictor for adverse LV remodelling. CONCLUSIONS: Intramyocardial haemorrhage and microvascular obstruction are strongly related. Pre-PCI TIMI 3 flow is less frequently observed in patients with MVO and IMH. Only infarct size was an independent predictor of LV remodelling

    Diagnostic evaluation of chest pain:The role of non-invasive cardiac imaging

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    Chest pain is a common symptom and can be caused by both cardiac and non-cardiac disorders. Non-invasive diagnostics is increasingly regarded as an essential part of the diagnostic evaluation in patients with chest pain, but inefficient and excessive use must be prevented. This dissertation describes the role of non-invasive diagnostics in patients with acute and chronic chest pain. In short, non-invasive diagnostics: 1) has no role in low risk acute chest pain, 2) can improve selection for invasive heart catheterizations in acute chest pain and suspicion of a heart attack, 3) can identify low risk patients if the test result is "negative" in patients with chronic chest pain, 4) cardiac MRI can identify an acute heart attack

    Orthopedic surgery increases atherosclerotic lesions and necrotic core area in ApoE-/- mice

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    Background and aims Observational studies show a peak incidence of cardiovascular events after major surgery. For example, the risk of myocardial infarction increases 25-fold early after hip replacement. The acuteness of this increased risk suggests abrupt enhancement in plaque vulnerability, which may be related to intra-plaque inflammation, thinner fibrous cap and/or necrotic core expansion. We hypothesized that acute systemic inflammation following major orthopedic surgery induces such changes. Methods ApoE−/− mice were fed a western diet for 10 weeks. Thereafter, half the mice underwent mid-shaft femur osteotomy followed by realignment with an intramedullary K-wire, to mimic major orthopedic surgery. Mice were sacrificed 5 or 15 days post-surgery (n = 22) or post-saline injection (n = 13). Serum amyloid A (SAA) was measured as a marker of systemic inflammation. Paraffin embedded slides of the aortic root were stained to measure total plaque area and to quantify fibrosis, calcification, necrotic core, and inflammatory cells. Results Surgery mice showed a pronounced elevation of serum amyloid A (SAA) and developed increased plaque and necrotic core area already at 5 days, which reached significance at 15 days (p = 0.019; p = 0.004 for plaque and necrotic core, respectively). Macrophage and lymphocyte density significantly decreased in the surgery group compared to the control group at 15 days (p = 0.037; p = 0.024, respectively). The density of neutrophils and mast cells remained unchanged. Conclusions Major orthopedic surgery in ApoE−/− mice triggers a systemic inflammatory response. Atherosclerotic plaque area is enlarged after surgery mainly due to an increase of the necrotic core. The role of intra-plaque inflammation in this response to surgical injury remains to be fully elucidated. © 2016 Elsevier Ireland Lt

    Abiotic stress QTL in lettuce crop–wild hybrids: comparing greenhouse and field experiments

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    The development of stress-tolerant crops is an increasingly important goal of current crop breeding. A higher abiotic stress tolerance could increase the probability of introgression of genes from crops to wild relatives. This is particularly relevant to the discussion on the risks of new GM crops that may be engineered to increase abiotic stress resistance. We investigated abiotic stress QTL in greenhouse and field experiments in which we subjected Recombinant Inbred Lines from a cross between cultivated Lactuca sativa cv. Salinas and its wild relative L. serriola to drought, low nutrients, salt stress, and above ground competition. Aboveground biomass at the end of the rosette stage was used as a proxy for the performance of plants under a particular stress. We detected a mosaic of abiotic stress QTL over the entire genome with little overlap between QTL from different stresses. The two QTL clusters that were identified reflected general growth rather than specific stress responses and co-located with clusters found in earlier studies for leaf shape and flowering time. Genetic correlations across treatments were often higher among different stress treatments within the same experiment (greenhouse or field), than among the same type of stress applied in different experiments. Moreover, the effects of the field stress treatments were more correlated to those of the greenhouse competition treatments than to those of the other greenhouse stress experiments, suggesting that competition rather than abiotic stress is a major factor in the field. In conclusion, the introgression risk of stress tolerance (trans-)genes under field conditions cannot easily be predicted based on genomic background selection patterns from controlled QTL experiments in greenhouses. Especially field data will be needed to assess potential (negative) ecological effects of introgression of these transgenes into wild relatives

    Effects of mixed versus blocked design on stimulus evaluation: combining underaddative effects.

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    (from the journal abstract) According to the asynchronous discrete coding model of Miller, two manipulations should display underadditive effects on reaction time if they slow down noncontingent stages associated with the processing of two separable dimensions of a stimulus. Underadditive effects are also predicted by a dual route model when a task variable is factorially varied with design type (mixed vs blocked). Interpretations of both underadditive effects and their combination were evaluated. Intact and degraded stimuli were presented to 18 young adults either in a single block (mixed) or in separate blocks (blocked). Spatial stimulus-response (S-R) compatibility was manipulated in all conditions. Stimulus degradation and S-R compatibility interacted underadditively, but only in blocked presentations. Both interpretations of underadditive effects were supported. Eye-movement registrations provided additional support for the alternative routes model

    Modeling and Simulation of Multi-Lane Traffic Flow

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    A most important aspect in the field of traffic modeling is the simulation of bottleneck situations. For their realistic description a macroscopic multi-lane model for uni-directional freeways including acceleration, deceleration, velocity fluctuations, overtaking and lane-changing maneuvers is systematically deduced from a gas-kinetic (Boltzmann-like) approach. The resulting equations contain corrections with respect to previous models. For efficient computer simulations, a reduced model delineating the coarse-grained temporal behavior is derived and applied to bottleneck situations.Comment: For related work see http://www.theo2.physik.uni-stuttgart.de/helbing.htm

    International comparisons of sectoral energy- and labour-productivity performance. Stylised facts and decomposition of trends

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    This paper addresses the interplay between economic growth, energy use, change in sectoral composition and technological change, by exploring trends in energy- and labour productivity development for 14 OECD countries and four sectors over the period 1970-1997. A cross-country decomposition analysis reveals that in some countries structural changes contributed considerably to macroeconomic energy-productivity growth while in other countries they partly offset energy-efficiency improvements. In contrast, structural changes only play a minor role in explaining macroeconomic labour-productivity developments. We also find labour productivity growth to be higher on average than energy productivity growth. Over time, this bias towards labour productivity growth is increasing in Transport, Agriculture and Manufacturing, while it is decreasing in Services
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