Micropillar compression study of Fe-irradiated 304L steel

Stainless steel used in nuclear reactors are experiencing heavy neutron irradiation that modify their microstructure, and therefore their mechanical properties. To assess the irradiation-induced hardening and the modification of deformation modes at the grain scale on 304L steels, indentations [1] and in situ microcompression tests were conducted on Fe-ions irradiated and non-irradiated FIB-made pillars [2]. 10 MeV and up to 8 dpa Fe irradiations were conducted at 450°C to surrogate neutron irradiation. Size effect was detected on unirradiated but not on irradiated pillars, revealing a strong impact of the microstructure on the mechanical behavior. Surprisingly, smoother plastic deformation took place in irradiated pillars while localized shear bands were observed in unirradiated ones. TEM investigations helped elaborating some hypothesis for this different behavior. Please click Additional Files below to see the full abstract

Relationships between bone geometry, volumetric bone mineral density and bone microarchitecture of the distal radius and tibia with alcohol consumption

PurposeChronic heavy alcohol consumption is associated with bone density loss and increased fracture risk, while low levels of alcohol consumption have been reported as beneficial in some studies. However, studies relating alcohol consumption to bone geometry, volumetric bone mineral density (vBMD) and bone microarchitecture, as assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), are lacking.MethodsHere we report an analysis from the Hertfordshire Cohort Study, in which we studied associations between HR-pQCT measures at the distal radius and tibia and alcohol consumption in 376 participants (198 men and 178 women) aged 72.1–81.4 years.ResultsA total of 30 (15.2%), 90 (45.5%) and 78 (39.4%) men drank minimal/none (< 1 unit/week), low (? 1 unit/week and < 11 units/week) and moderate/high (? 11 units/week) amounts of alcohol respectively. These figures were 74 (41.8%), 80 (45.2%) and 23 (13.0%) respectively in women for minimal/none (< 1 unit/week), low (? 1 unit/week and < 8 units/week) and moderate/high (? 8 units/week). At the distal radius, after adjustment for confounding factors (age, BMI, smoking status, dietary calcium intake, physical activity and socioeconomic status and years since menopause and HRT use for women), men that drank low alcohol had lower cortical thickness (p = 0.038), cortical vBMD (p = 0.033), and trabecular vBMD (p = 0.028) and higher trabecular separation (p = 0.043) than those that drank none/minimal alcohol. Similar differences were shown between minimal/none and moderate/high alcohol although these only reached statistical significance for the cortical parameters. Interestingly, after similar adjustment, women showed similar differences in the trabecular compartment between none/minimal alcohol and low alcohol at the distal tibia. However, women that drank moderate/high alcohol had significantly higher trabecular vBMD (p = 0.007), trabecular thickness (p = 0.026), and trabecular number (p = 0.042) and higher trabecular separation (p = 0.026) at the distal radius than those that drank low alcohol.ConclusionsOur results suggest that alcohol consumption (low and moderate/high) may have a detrimental impact on bone health in men in both the cortical and trabecular compartments at the distal radius with similar results in women in the trabecular compartment between none/minimal alcohol and low alcohol at the distal tibia suggesting that avoidance of alcohol may be beneficial for bone health.AbbreviationsaBMD, areal bone mineral density; BMI, body mass index; Ct. area, cortical area; Ct.vBMD, cortical density; Ct.Po, cortical porosity; Ct.Th, cortical thickness; DXA, dual energy X-ray absorptiometry; HCS, Hertfordshire Cohort Study; HRpQCT, high-resolution peripheral quantitative computed tomography; pQCT, peripheral quantitative computed tomography; Tt.area, total cross-sectional area; Tb.vBMD, trabecular BMD; Tb.N, trabecular number; Tb.Th, trabecular thickness; Tb.Sp, trabecular separation; vBMD, volumetric bone mineral density

A conservative coupling algorithm between a compressible flow and a rigid body using an Embedded Boundary method

This paper deals with a new solid-fluid coupling algorithm between a rigid body and an unsteady compressible fluid flow, using an Embedded Boundary method. The coupling with a rigid body is a first step towards the coupling with a Discrete Element method. The flow is computed using a Finite Volume approach on a Cartesian grid. The expression of numerical fluxes does not affect the general coupling algorithm and we use a one-step high-order scheme proposed by Daru and Tenaud [Daru V,Tenaud C., J. Comput. Phys. 2004]. The Embedded Boundary method is used to integrate the presence of a solid boundary in the fluid. The coupling algorithm is totally explicit and ensures exact mass conservation and a balance of momentum and energy between the fluid and the solid. It is shown that the scheme preserves uniform movement of both fluid and solid and introduces no numerical boundary roughness. The effciency of the method is demonstrated on challenging one- and two-dimensional benchmarks

Solidaires, unitaires et démocratiques: social movement unionism and beyond?

A contribution to a Special Issue on trade union renewal that focuses on this topic in relation to the radical French trade union Solidaires, Unitaires et Démocratiques (SUD)

Severe osteoporosis: diagnosis and follow-up. Lessons for clinical practice

The management of osteoporosis has improved considerably, leading to the development of new goals. A major concern today is the management of patients with severe osteoporosis, in whom the need for pharmacotherapy is clear [1]. Epidemiological data have established that osteoporosis is associated with severe complications [2,3]. Furthermore, osteoporosis is now recognized as a complication of several chronic diseases, whose presence adversely affects the management of osteoporosis. The ODISSEE task force (Osteoporosis DIagnosis and Surveillance of SEvErity) was established to answer practical questions regarding the management of severe osteoporosis, based on evidence in the literature. Several groups conducted an exhaustive literature review, and advice was obtained from a panel of French rheumatologists. The ODISSEE scientific committee then developed the first consensus statement on the diagnosis, follow-up and management of severe osteoporosis. This statement was validated by a panel of 70 French rheumatologists at the first national ODISSEE meeting held on November 13-14, 2009

Relationship between Low Bone Mineral Density and Fractures with Incident Cardiovascular Disease: A Systematic Review and Meta-analysis

An increasing evidence base suggests that low bone mineral density (BMD) and fractures are associated with cardiovascular disease (CVD). We conducted a systematic review and meta-analysis summarizing the evidence of low BMD and fractures as risk factors for future CVD. Two independent authors searched major databases from inception to 1st August 2016 for longitudinal studies reporting data on CVD incidence (overall and specific CVD) and BMD status and fractures. The association between low BMD, fractures and CVD across longitudinal studies was explored by calculating pooled adjusted hazard ratios (HRs) ± 95% confidence intervals (CIs) with a random-effects meta-analysis. Twenty-eight studies (18 regarding BMD and 10 fractures) followed-up a total of 1,107,885 participants for a median of 5 years. Taking those with higher BMD as the reference, people with low BMD were at increased risk of developing CVD during follow-up (11 studies; HR = 1.33; 95%CI: 1.27-1.38; I2  = 53%), after adjusting for a median of 8 confounders. This finding was confirmed using a decrease in one standard deviation of baseline BMD (9 studies; HR = 1.16; 95%CI: 1.09-1.24; I2  = 69%). The presence of fractures at baseline was associated with an increased risk of developing CVD (HR = 1.20; 95%CI: 1.06-1.37; I2  = 91%). Regarding specific CVD, low BMD was associated with an increased risk of developing coronary artery disease, cerebrovascular conditions, and CVD associated death. Fractures at baseline was associated with an increased risk of cerebrovascular conditions and death due to CVD. In conclusion, low BMD and fractures are associated with a small, but significant increased risk of CVD risk and possibly death

European Cystic Fibrosis Society standards of care: best practice guidelines

Specialised CF care has led to a dramatic improvement in survival in CF: in the last four decades, well above what was seen in the general population over the same period. With the implementation of newborn screening in many European countries, centres are increasingly caring for a cohort of patients who have minimal lung disease at diagnosis and therefore have the potential to enjoy an excellent quality of life and an even greater life expectancy than was seen previously. To allow high quality care to be delivered throughout Europe, a landmark document was published in 2005 that sets standards of care. Our current document builds on this work, setting standards for best practice in key aspects of CF care. The objective of our document is to give a broad overview of the standards expected for screening, diagnosis, pre-emptive treatment of lung disease, nutrition, complications, transplant/end of life care and psychological support. For comprehensive details of clinical care of CF, references to the most up to date European Consensus Statements, Guidelines or Position Papers are provided in Table 1. We hope that this best practice document will be useful to clinical teams both in countries where CF care is developing and those with established CF centres