Strand plasticity governs fatigue in colloidal gels

Repeated loading of a solid leads to microstructural damage that ultimately results in catastrophic material failure. While posing a major threat to the stability of virtually all materials, the microscopic origins of fatigue, especially for soft solids, remain elusive. Here we explore fatigue in colloidal gels as prototypical inhomogeneous soft solids by combining experiments and computer simulations. Our results reveal how mechanical loading leads to irreversible strand stretching, which builds slack into the network that softens the solid at small strains and causes strain hardening at larger deformations. We thus find that microscopic plasticity governs fatigue at much larger scales. This gives rise to a new picture of fatigue in soft thermal solids and calls for new theoretical descriptions of soft gel mechanics in which local plasticity is taken into account.Comment: 5 pages, 4 figure

Oxygen transport through La@1-x]Sr@x]FeO@3-gamma] membranes. I. Permeation in air/He gradients

Oxygen permeation measurements in air/He gradients were performed on dense La1 ¿ xSrxFeO3 ¿ ¿ membranes in the composition range x = 0.1¿0.4 and temperature range 1123¿1323 K. Pretreatment of the lower oxygen partial pressure side of the membranes in a CO-containing atmosphere for several hours at 1273 K led to higher oxygen fluxes, which were in the range of 0.1¿4.5 mmol m¿2 s¿1. After treatment, the observed oxygen fluxes could be described in terms of bulk diffusion-limited permeation behaviour. Experimental evidence for a bulk-diffusion controlled flux was found from thickness dependence measurements on membranes with thicknesses between 0.5 mm and 2.0 mm. Model calculations, based on Wagner theory in conjunction with data of oxygen nonstoichiometry and vacancy diffusion coefficients from literature, were performed. The experimental flux values deviated from the model calculations with factors up to 2.5. Adjustment of the value of the vacancy diffusion coefficient led to good agreement between the experimental data and the model calculations. The calculated vacancy diffusion coefficients Dv0 were virtually independent of composition and were found to be in the range 5.3¿9.3 × 10¿6 cm2 s¿1

Massive intraventricular haemorrhage from aneurysmal rupture: patient proportions and eligibility for intraventricular fibrinolysis

Massive intraventricular haemorrhage (IVH) complicating aneurysmal subarachnoid haemorrhage (SAH) is associated with a poor prognosis. Small observational studies suggest favourable results from fibrinolysis of the intraventricular blood. We performed an observational study on IVH in a large series of patients with SAH to assess the proportion of patients that may benefit from fibrinolytic treatment. From our prospective database we retrieved patients with aneurysmal SAH admitted between January 2000 and January 2005. We calculated the proportion of patients with massive IVH and the proportion of patients that are eligible for fibrinolysis on basis of clinical and CT-scan characteristics and assessed neurological outcome in a treatment strategy without fibrinolysis. Poor neurological condition was defined as World Federation of Neurological Surgeons scale 4 and 5, poor outcome as death or dependence 3 months after SAH. Of the 573 patients admitted with aneurysmal SAH, 59 (10%; 95% confidence interval CI 8–13%) had massive IVH, of which 55 were in poor clinical condition. For these 55 patients, the case-fatality rate was 78% (95% CI 66–88%) and the proportion with poor outcome 91% (95% CI 81–97%). Of the 55 patients, 31 (56%, and 5% of all patients SAH within the study period) fulfilled our eligibility criteria and were considered suitable for intraventricular fibrinolysis. At 3 months, 30 of these 31 eligible patients (97%; 95% CI 85–100%) had a poor outcome. Massive IVH occurs in 10% of patients with aneurysmal SAH. Half of these patients may benefit from intraventricular fibrinolysis. Without fibrinolysis outcome is almost invariably poor in these patients

Human health in the flood risk management planning under the European Union Floods Directive: Pilot study in the Sava River Basin

The EU Floods Directive (2007/60/EC) has the purpose to establish a framework for the flood risks assessment and management. It requires the implementation of coordinated measures on a basin-wide level for the reduction of adverse consequences to human health and life. However, mainly direct fatalities are taken into consideration in these plans. To develop more integrated and adaptive risk management and governance it is important to include both direct and indirect consequences. To define effective measures clearer understanding of the relation between floods and impact on human health is needed. We present a first attempt to provide a roadmap for the inclusion of health issues of concern to flood risk management within the Sava River Basin as an example. An overview of the potential flood effects to health issues was made and a roadmap plan was set up to analyse and map these flood risks. We concluded that indirect health effects can contribute significantly to the overall adverse consequences to health, and although relations are complex, a preliminary assessment could be made. Mapping of adverse consequences to health issues in the planning stages should lead to systemic insights and proposed measures in the prevention, protection, and preparedness while considering the characteristics of the river basin or sub-basins. By incorporating a health-risk-analysis in the planning process, health-oriented preparation is not only aimed at improving post-flood relief efforts, but to minimise the actual impacts and decrease post flood recovery time and costs

The association of genetic predisposition to depressive symptoms with non-suicidal and suicidal self-Injuries

Non-suicidal and suicidal self-injury are very destructive, yet surprisingly common behaviours. Depressed mood is a major risk factor for non-suicidal self-injury (NSSI), suicidal ideation and suicide attempts. We conducted a genetic risk prediction study to examine the polygenic overlap of depressive symptoms with lifetime NSSI, suicidal ideation, and suicide attempts in a sample of 6237 Australian adult twins and their family members (3740 females, mean age\ua0=\ua042.4\ua0years). Polygenic risk scores for depressive symptoms significantly predicted suicidal ideation, and some predictive ability was found for suicide attempts; the polygenic risk scores explained a significant amount of variance in suicidal ideation (lowest p\ua0=\ua00.008, explained variance ranging from 0.10 to 0.16\ua0%) and, less consistently, in suicide attempts (lowest p\ua0=\ua00.04, explained variance ranging from 0.12 to 0.23\ua0%). Polygenic risk scores did not significantly predict NSSI. Results highlight that individuals genetically predisposed to depression are also more likely to experience suicidal ideation/behaviour, whereas we found no evidence that this is also the case for NSSI

High microsatellite and SNP genotyping success rate established in a large number of genomic DNA samples extracted from mouth swabs and genotypes

In this article, we present the genomic DNA yield and the microsatellite and single nucleotide polymorphism (SNP) genotyping success rates of genomic DNA extracted from a large number of mouth swab samples. In total, the median yield and quality was determined in 714 individuals and the success rates in 378,480 genotypings of 915 individuals. The median yield of genomic DNA per mouth swab was 4.1 μg (range 0.1-42.2 μg) and was not reduced when mouth swabs were stored for at least 21 months prior to extraction. A maximum of 20 mouth swabs is collected per participant. Mouth swab samples showed in, respectively, 89% for 390 microsatellites and 99% for 24 SNPs a genotyping success rate higher than 75%. A very low success rate of genotyping (0%-10%) was obtained for 3.2% of the 915 mouth swab samples using microsatellite markers. Only 0.005% of the mouth swab samples showed a genotyping success rate lower than 75% (range 58%-71 %) using SNPs. Our results show that mouth swabs can be easily collected, stored by our conditions for months prior to DNA extraction and result in high yield and high-quality DNA appropriate for genotyping with high success rate including whole genome searches using microsatellites or SNPs

Dutch guidelines on care for extremely premature infants:Navigating between personalisation and standardization

OBJECTIVE: There is no international consensus on what type of guideline is preferred for care at the limit of viability. We aimed to conceptualize what type of guideline is preferred by Dutch healthcare professionals: 1) none; 2) gestational-age-based; 3) gestational-age-based-plus; or 4) prognosis-based via a survey instrument. Additional questions were asked to explore the grey zone and attitudes towards treatment variation. FINDING: 769 surveys were received. Most of the respondents (72.8%) preferred a gestational-age-based-plus guideline. Around 50% preferred 24+0/7 weeks gestational age as the lower limit of the grey zone, whereas 26+0/7 weeks was the most preferred upper limit. Professionals considered treatment variation acceptable when it is based upon parental values, but unacceptable when it is based upon the hospital's policy or the physician's opinion. CONCLUSION: In contrast to the current Dutch guideline, our results suggest that there is a preference to take into account individual factors besides gestational age

Raw genome sequence data for 13 isogenic Aspergillus fumigatus strains isolated over a 2 year period from a patient with chronic granulomatous disease

EB, AB and AW are supported by the Wellcome Trust Strategic Award (grant 097377), and the MRC Centre for Medical Mycology at the University of Aberdeen (grant MR/N006364/1). AB was also supported by the Biotechnology and Biological Research Council (BB/K017365/1) and the Medical Research Council (MR/M026663/1). The work in this paper is funded by a BBSRC EASTBIO grant (BB/M010996/1) awarded to AW. The funders had no role in study design, data interpretation, or the decision to submit the work for publication.Peer reviewedPublisher PD