215 research outputs found
Modelling avalanches in martensites
Solids subject to continuous changes of temperature or mechanical load often
exhibit discontinuous avalanche-like responses. For instance, avalanche
dynamics have been observed during plastic deformation, fracture, domain
switching in ferroic materials or martensitic transformations. The statistical
analysis of avalanches reveals a very complex scenario with a distinctive lack
of characteristic scales. Much effort has been devoted in the last decades to
understand the origin and ubiquity of scale-free behaviour in solids and many
other systems. This chapter reviews some efforts to understand the
characteristics of avalanches in martensites through mathematical modelling.Comment: Chapter in the book "Avalanches in Functional Materials and
Geophysics", edited by E. K. H. Salje, A. Saxena, and A. Planes. The final
publication is available at Springer via
http://dx.doi.org/10.1007/978-3-319-45612-6_
Diffusion-weighted imaging lesions and risk of recurrent stroke after intracerebral haemorrhage
OBJECTIVE: To determine whether the presence of diffusion-weighted imaging-positive (DWI+) lesions is associated with recurrent stroke after intracerebral haemorrhage (ICH). METHODS: The REstart or STop Antithrombotics Randomised Trial (RESTART) assessed the effect of restarting versus avoiding antiplatelet therapy after ICH on major vascular events for up to 5 years. We rated DWI sequences of MRI done before randomisation for DWI+ lesion presence, masked to outcome and antiplatelet use. Cox proportional hazards regression models were used to quantify associations. RESULTS: Of 537 participants in RESTART, 247 (median (IQR) age 75.7 (69.6-81.1) years; 170 men (68.8%); 120 started vs 127 avoided antiplatelet therapy) had DWI sequences on brain MRI at a median of 57 days (IQR 19-103) after ICH, of whom 73 (30%) had one or more DWI+ lesion. During a median follow-up of 2 years (1-3), 18 participants had recurrent ICH and 21 had ischaemic stroke. DWI+ lesion presence was associated with all stroke, (adjusted HR 2.2 (95% CI 1.1 to 4.2)) and recurrent ICH (4.8 (95% CI 1.8 to 13.2)), but not ischaemic stroke (0.9 (95% CI 0.3 to 2.5)). DWI+ lesion presence (0.5 (95% CI 0.2 to 1.3)) vs absence (0.6 (95% CI 0.3 to 1.5), pinteraction=0.66) did not modify the effect of antiplatelet therapy on a composite outcome of recurrent stroke. CONCLUSIONS: DWI+ lesion presence in ICH survivors is associated with recurrent ICH, but not with ischaemic stroke. We found no evidence of modification of effects of antiplatelet therapy on recurrent stroke after ICH by DWI+ lesion presence. These findings provide a new perspective on the significance of DWI+ lesions, which may be markers of microvascular mechanisms associated with recurrent ICH. TRIAL REGISTRATION NUMBER: ISRCTN71907627
Association between critical care admission and 6-month functional outcome after spontaneous intracerebral haemorrhage
BACKGROUND: There is uncertainty about the clinical benefit of admission to critical care after spontaneous intracerebral haemorrhage (ICH). PURPOSE: We investigated factors associated with critical care admission after spontaneous ICH and evaluated associations between critical care and 6-month functional outcome. METHODS: We included 825 patients with acute spontaneous non-traumatic ICH, recruited to a prospective multicenter observational study. We evaluated the characteristics associated with critical care admission and poor 6-month functional outcome (modified Rankin Scale, mRS > 3) using univariable (chi-square test and Wilcoxon rank-sum test, as appropriate) and multivariable analysis. RESULTS: 286 patients (38.2%) had poor 6-month functional outcome. Seventy-seven (9.3%) patients were admitted to critical care. Patients admitted to critical care were younger (p < 0.001), had lower GCS score (p < 0.001), larger ICH volume (p < 0.001), more often had intraventricular extension (p = 0.008) and underwent neurosurgery (p < 0.001). Critical care admission was associated with poor functional outcome at 6 months (39/77 [50.7%] vs 286/748 [38.2%]; p = 0.034); adjusted OR 2.43 [95%CI 1.36-4.35], p = 0.003), but not with death (OR 1.29 [95%CI 0.71-2.35; p = 0.4). In ordinal logistic regression, patients admitted to critical care showed an OR 1.47 (95% CI 0.98-2.20; p = 0.07) for a shift in the 6-month modified Rankin Scale. CONCLUSIONS: Admission to critical care is associated with poor 6-month functional outcome after spontaneous ICH but not with death. Patients admitted to critical care were a priori more severely affected. Although adjusted for main known predictors of poor outcome, our findings could still be confounded by unmeasured factors. Establishing the true effectiveness of critical care after ICH requires a randomised trial with clinical outcomes and quality of life assessments
The impact of sex on severe asthma: a cross-sectional retrospective analysis of UK primary and specialist care:a cross-sectional retrospective analysis of UK primary and specialist care
After puberty, females are more likely to develop asthma and in a more severe form than males. The associations between asthma and sex are complex with multiple intrinsic and external factors. To evaluate the sex differences in the characteristics and treatment of patients with severe asthma (SA) in a real-world setting. Demographic, clinical and treatment characteristics for patients with SA in the UK Severe Asthma Registry (UKSAR) and Optimum Patient Care Research Database (OPCRD) were retrospectively analysed by sex using univariable and multivariable logistic regression analyses adjusted for year, age and hospital/practice. 3679 (60.9% female) patients from UKSAR and 18â369 patients (67.9% female) from OPCRD with SA were included. Females were more likely to be symptomatic with increased Asthma Control Questionnaire-6 (UKSAR adjusted OR (aOR) 1.14, 95%âCI 1.09 to 1.18) and Royal College of Physicians-3 Question scores (OPCRD aOR 1.29, 95% CI 1.13 to 1.47). However, they had a higher forced expiratory volume in 1 second per cent (FEV %) predicted (UKSAR 68.7% vs 64.8%,
Pro- and antisaccades in children elicited by visual and acoustic targets - does modality matter?
Peer reviewedPublisher PD
Transarterial chemoembolisation (TACE) using irinotecan-loaded beads for the treatment of unresectable metastases to the liver in patients with colorectal cancer: an interim report
<p>Abstract</p> <p>Background</p> <p>Following failure of standard systemic chemotherapy, the role of hepatic transarterial therapy for colorectal hepatic metastasis continues to evolve as the experience with this technique matures. The aim of this study to gain a better understanding of the value of drug eluting bead therapy when administered to patients with unresectable colorectal hepatic metastasis.</p> <p>Methods</p> <p>This was an open-label, multi-center, single arm study, of unresectable colorectal hepatic metastasis patients who had failed standard therapy from 10/2006-10/2008. Patients received repeat embolizations with Irinotecan loaded beads(max 100 mg per embolization) per treating physician's discretion.</p> <p>Results</p> <p>Fifty-five patients underwent 99 treatments using Irinotecan drug eluting beads. The median number of total treatments per patient was 2(range of 1-5). Median length of hospital stay was 23 hours(range 23 hours - 10 days). There were 30(30%) sessions associated with adverse reactions during or after the treatment. The median disease free and overall survival from the time of first treatment was 247 days and 343 days. Six patients(10%) were downstaged from their original disease status. Of these, four were treated with surgery and two with RFA.</p> <p>Neither number of liver lesions, size of liver lesions or extent of liver replacement(<= 25% vs >25%) were predictors of overall survival. Only the presence of extrahepatic disease(p = 0,001), extent of prior chemotherapy (failed 1<sup>st </sup>and 2<sup>nd </sup>line vs > 2 line failure)(p = 0,007) were predictors of overall survival in multivariate analysis.</p> <p>Conclusion</p> <p>Chemoembolization using Irinotecan loaded beads was safe and effective in the treatment of patients as demonstrated by a minimal complication rate and acceptable tumor response.</p
Antihypertensive, antidyslipidemic and endothelial modulating activities of Orchis mascula
The objective of this study was to investigate the possible mode(s) of action for the medicinal use of Orchis mascula (OM) (family Orchidaceae) in hypertension and dyslipidemia. In spontaneously hypertensive rats (SHRs), OM significantly (
Concepts for risk-based surveillance in the field of veterinary medicine and veterinary public health: Review of current approaches
BACKGROUND: Emerging animal and zoonotic diseases and increasing international trade have resulted in an increased demand for veterinary surveillance systems. However, human and financial resources available to support government veterinary services are becoming more and more limited in many countries world-wide. Intuitively, issues that present higher risks merit higher priority for surveillance resources as investments will yield higher benefit-cost ratios. The rapid rate of acceptance of this core concept of risk-based surveillance has outpaced the development of its theoretical and practical bases. DISCUSSION: The principal objectives of risk-based veterinary surveillance are to identify surveillance needs to protect the health of livestock and consumers, to set priorities, and to allocate resources effectively and efficiently. An important goal is to achieve a higher benefit-cost ratio with existing or reduced resources. We propose to define risk-based surveillance systems as those that apply risk assessment methods in different steps of traditional surveillance design for early detection and management of diseases or hazards. In risk-based designs, public health, economic and trade consequences of diseases play an important role in selection of diseases or hazards. Furthermore, certain strata of the population of interest have a higher probability to be sampled for detection of diseases or hazards. Evaluation of risk-based surveillance systems shall prove that the efficacy of risk-based systems is equal or higher than traditional systems; however, the efficiency (benefit-cost ratio) shall be higher in risk-based surveillance systems. SUMMARY: Risk-based surveillance considerations are useful to support both strategic and operational decision making. This article highlights applications of risk-based surveillance systems in the veterinary field including food safety. Examples are provided for risk-based hazard selection, risk-based selection of sampling strata as well as sample size calculation based on risk considerations
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