1,239 research outputs found
Creep behavior of a γ′-strengthened Co-base alloy with zero γ/γ′-lattice misfit at 800 °C, 196 MPa
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Deformation and structural behavior of an experimental γ′-strengthened Co-base alloy during creep at 800 °C and 196 MPa have been investigated. The characteristic features of this alloy are zero γ/γ′-lattice misfit and a fine γ/γ′-microstructure. In the initial condition, the γ′-precipitates in this alloy are small (size of about 100 nm), have polyhedral morphology, and are separated by the very narrow γ-channels (width of about 10 nm). The tests performed up to about 1% creep strain (about 500 h creep time) gave creep curves with a slow constant strain rate and without an apparent transient creep, typical for superalloys with nonzero misfit. In this initial stage of creep, entering of the narrow γ-channels by dislocations is blocked by a strong Orowan force. The micromechanism of creep was identified as an octahedral glide of 〈011〉 superdislocations simultaneously in two phases, γ and γ′. The γ/γ′-microstructure with zero misfit shows no rafting but rapidly coarsens isotropically. It is concluded that zero misfit is beneficial at the initial stages of the creep but is unfavourable for long-term creep because of the continuous microstructural coarsening
760-4 Initial Multicenter Experience with Therapeutic Ultrasonic Coronary Angioplasty in Patients
Therapeutic ultrasonic (195 kHz) catheters with 1.2 or 1.7 mm ball tips for coronary angioplasty have recently been developed. During the first phase of a multi-center European trial (CRUSADE) this system was evaluated in 100 patients (86% male, mean age 57 years) with symptomatic coronary artery disease or acute myocardial infarction. Lesions were located in the LAD (n = 61), CX (n = 17), and RCA (n = 22); 62% were type B or C; 11 lesions were restenotic, 19 occlusive, 9 longer than 20 mm, 37 calcified, 18 thrombotic, and 15 collateralised.ResultsThe ultrasound catheter crossed 82/100 lesions, adjunctive balloon angioplastywas needed in 98 lesions. There was no death and myocardial infarction, or CABG in the first 24 hours. There was no perforation, but 2 acute vessel closures; intimal cleft or dissection was seen in 17 lesions of which 1 required stenting. Procedural success was obtained in 93%. At 24 hours 11/100 vessels were reoccluded. At 6 months angiographic follow-up in 51 patients restenosis (>50% stenosis) occured in 33%.ConclusionsTherapeutic ultrasound angioplasty is a feasible and safe new treatment modality. Adjunctive balloon angioplasty is regularly necessary. Preliminary experience suggests usefulness in lesions with visible thrombus, and undilatable or uncrossable lesions
Literatur der Archäologie: Materialität und Rhetorik im 18. und 19. Jahrhundert
Seit der Einführung des Konzepts einer »Archäologie
des Wissens« ist wiederholt versucht worden, den Begriff
der Archäologie für eine allgemeine Kulturtheorie
zu funktionalisieren. Umfangreich erschienen in der
Folge die Archäologien, als deren Gegenstände nicht
einmal mehr die Gegenwart oder die Zukunft undenkbar
sind. Daneben musste sich, wie alle Kulturwissenschaften,
das institutionelle Fach Archäologie mit dem
prägenden Einfluss sprachlicher Bedingungen auf die
Gewinnung von Erkenntnissen auseinandersetzen. Dies
verweist auf eine zentrale Problematik, die eng an der
Kombination von Archäologie und Germanistik in der
konzeptionellen Gestaltung des Forschungskollegs
Morphomata orientiert ist, nämlich das wechselseitige
Verhältnis visuell wahrgenommener und literarisch
vermittelter Form sowie ihre Bezüge zu einer ihnen
zugrunde liegenden Vorstellung.
Der vorliegende Sammelband will über Fallbeispiele
aus den Blickwinkeln der Fachdisziplinen der Archäologie
und der Literaturwissenschaften Veränderungen
und Persistenzen in der Erschließung von Antike deutlich
machen. Im Zentrum der Beiträge stehen erstens
die Verwendung des Begriffs »Archäologie« außerhalb
des aus heutiger Sicht dafür charakteristischen Feldes
der Ausgrabung und deutenden Erfassung überlieferter
materialer Fundstücke, zweitens die dichterische Darstellung
archäologischer Tätigkeit im modernen Sinne
der sich ausbildenden Fachdisziplin und drittens Literatur
als Medium der Formulierung und Systematisierung
generierter Wissensbestände bzw. intersubjektiver
Diskursivität der Archäologie
Atomically sharp domain walls in an antiferromagnet
The interest in understanding scaling limits of magnetic textures such as
domain walls spans the entire field of magnetism from its relativistic quantum
fundamentals to applications in information technologies. The traditional focus
of the field on ferromagnets has recently started to shift towards
antiferromagnets which offer a rich materials landscape and utility in
ultra-fast and neuromorphic devices insensitive to magnetic field
perturbations. Here we report the observation that domain walls in an epitaxial
crystal of antiferromagnetic CuMnAs can be atomically sharp. We reveal this
ultimate domain wall scaling limit using differential phase contrast imaging
within aberrationcorrected scanning transmission electron microscopy, which we
complement by X-ray magnetic dichroism microscopy and ab initio calculations.
We highlight that the atomically sharp domain walls are outside the remits of
established spin-Hamiltonian theories and can offer device functionalities
unparalleled in ferromagnets.Comment: 8 pages, 4 figures, Supplementary informatio
Protocol for the process evaluation of a complex, statewide intervention to reduce salt intake in Victoria, Australia
Systematic reviews of trials consistently demonstrate that reducing salt intake lowers blood pressure. However, there is limited evidence on how interventions function in the real world to achieve sustained population-wide salt reduction. Process evaluations are crucial for understanding how and why an intervention resulted in its observed effect in that setting, particularly for complex interventions. This project presents the detailed protocol for a process evaluation of a statewide strategy to lower salt intake in Victoria, Australia. We describe the pragmatic methods used to collect and analyse data on six process evaluation dimensions: reach, dose or adoption, fidelity, effectiveness, context and cost, informed by Linnan and Steckler’s framework and RE-AIM. Data collection methods include routinely collected administrative data; surveys of processed foods, the population, food industry and organizations; targeted campaign evaluation and semi-structured interviews. Quantitative and qualitative data will be triangulated to provide validation or context for one another. This process evaluation will contribute new knowledge about what components of the intervention are important to salt reduction strategies and how the interventions cause reduced salt intake, to inform the transferability of the program to other Australian states and territories. This protocol can be adapted for other population-based, complex, disease prevention interventions
The effect of aspirin and nonsteroidal anti-inflammatory drug use after diagnosis on survival of oesophageal cancer patients
Background:Aspirin use has been shown to lower incidence and mortality in cancer patients. The aim of this population-based study was to determine the effect of postdiagnosis low-dose aspirin use on survival of patients with oesophageal cancer.Methods:Patients with oesophageal cancer (1998-2010) were selected from the Eindhoven Cancer Registry and linked with outpatient pharmacy data regarding aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs). Users were subdivided into both prediagnosis and postdiagnosis or only postdiagnosis users. Parametric survival models with an exponential (Poisson) distribution were used with non-specific death as endpoint.Results:In this study 560 patients were included. Overall, 157 patients (28.0%) were non-users, 293 patients (52.3%) pre-and postdiagnosis (89 aspirin and 204 NSAID users) and 110 patients (19.6%) only postdiagnosis users (16 aspirin and 94 NSAID users). Postdiagnosis aspirin use was associated with overall survival (RR 0.45 (95% CI 0.34-0.60; P<0.001); adjusted rat
Evaluation of a Salt-Reduction Consumer Awareness Campaign Targeted at Parents Residing in the State of Victoria, Australia
From 2015 to 2020 a state-wide salt-reduction initiative was launched in Victoria, Australia, including an awareness campaign focused on parents with children <18 years of age. To evaluate the impact of the campaign on salt-related knowledge, attitudes and behaviors (KABs) we have assessed trends in salt-related KAB pre- and post-delivery of the campaign in parents, as well as within the wider adult population. Cross-sectional surveys of adults aged 18–65 years were undertaken pre- (2015: n = 821 parents; n = 1527 general sample) and post-campaign (2019: n = 935 parents; n = 1747 general sample). KABs were assessed via an online survey. Data were analyzed with regression models and adjusted for covariates. Among parents, around one-quarter of salt-related KABs shifted in a positive direction, but changes were small: there was a 6% (95% CI 2, 11%) increase in the percentage who knew the main source of salt in the diet and reductions in the percentage who reported placing a salt shaker on the table (−8% (95%CI −12, −3)) and that their child added salt at the table (−5% (95% −9, −0.2)). Among the wider adult sample, even fewer shifts in KAB were observed, with some behaviors worsening at follow-up. These findings indicate that this consumer awareness campaign had minimum impact
The influence of BRAF and KRAS mutation status on the association between aspirin use and survival after colon cancer diagnosis
Background: Use of aspirin after diagnosis of colon cancer has been associated with improved survival. Identification of cancer subtypes that respond to aspirin treatment may help develop personalized treatment regimens. The aim of this study was to investigate the influence of BRAF and KRAS mutation status on the association between aspirin use and overall survival after colon cancer diagnosis. Methods: A random selection of 599 patients with colon cancer were analyzed, selected from the Eindhoven Cancer Registry, and BRAF and KRAS mutation status was determined. Data on aspirin use (80 mg) were obtained from the PHARMO Database Network. Parametric survival models with exponential (Poisson) distribution were used. Results: Aspirin use after colon cancer diagnosis was associated with improved overall survival in wild-type BRAF tumors, adjusted rate ratio (RR) of 0.60 (95% CI 0.44-0.83). In contrast, aspirin use in BRAF mutated tumors was not associated with an improved survival (RR 1.11, 95% CI 0.57-2.16). P-value for interaction was non-significant. KRAS mutational status did not differentiate in the association between aspirin use and survival. Conclusion: Low-dose aspirin use after colon cancer diagnosis was associated with improved survival in BRAF wild-type tumors only. However, the large confidence interval of the rate ratio for the use of aspirin in patients with BRAF mutation does not rule out a possible benefit. These results preclude BRAF and KRAS mutation status to be used as a marker for individualized treatment with aspirin, if aspirin becomes regular adjuvant treatment for colon cancer patients in the future
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