Numerical investigation of the equipment set-up in triaxial testing of soft soils

Element testing of soft soils is challenging due to the large strains attained in the pre-failure range. Besides the heterogeneity of natural samples, the set-up configuration is the main driving factor for non-homogenous response. Stress, strain and pore pressure non-uniformities induced by the loading system affect the observed behaviour and complicate proper interpretation of the results. Among the difficulties encountered in the interpretation of laboratory data, the unexpected decrease of the stress ratio frequently observed on Dutch organic soft clays on the wet side of critical state is investigated by numerically back-analysing the triaxial test set-up. A 3D finite element simulation using an advanced constitutive model for soft clays developed at TU Delft was performed to clarify the nature of the response. The results indicate that a decrease in the deviatoric stress up to critical state may be interpreted as a true feature of the soil response. However, the response at large strains is very much influenced by the triaxial shear apparatus, in particular, by the rotation of the top cap which triggers geometrical instability. Practical recommendations are given to limit the effects of the set-up configuration on the determination of the undrained shear strength to be used for field applications

Interpreting repeated CPT in unsaturated soils

Cone penetration tests, CPTs, are extensively used in the Netherlands to assess the stability of fourteen thousand kilometres of dykes protecting the country from flooding. On the regional dykes, site testing is planned and executed only from spring to autumn. The data collected in the drier season of the year must be used then in safety factor calculation for dyke stability with reference to the worst expected conditions, including the highest weights and the highest water pressures over the year. Inferring reliable values of the shear strength in a different season implies understanding the unsaturated response of the dyke material and the effect of variable water content on the CPT response. In previous studies referring to CPTs in unsaturated soils, it was observed that both the cone resistance and the sleeve friction depend on suction, however, only the cone resistance was used to determine the shear strength in combination with water content or suction probes installed into the ground. In this contribution, we analyse an extensive set of data, coming from repeated CPTs performed over one year on the Maasdijk near Oijen in the Netherlands. The data are elaborated to investigate whether the entire set of data can be exploited to try to derive the water content and the constant water content shear strength at the same time, if the test is repeated in different seasons

Worse Physical Disability Is Associated With the Expression of PD-1 on Inflammatory T-Cells in Multiple Sclerosis Patients With Older Appearing Brains

Background: Magnetic Resonance Imaging (MRI) analysis method “brain-age” paradigm could offer an intuitive prognostic metric (brain-predicted age difference: brain-PAD) for disability in Multiple Sclerosis (MS), reflecting structural brain health adjusted for aging. Equally, cellular senescence has been reported in MS using T-cell biomarker CD8+CD57+. Objective: Here we explored links between MRI-derived brain-age and blood-derived cellular senescence. We examined the value of combining brain-PAD with CD8+CD57+(ILT2+PD-1+) T-cells when predicting disability score in MS and considered whether age-related biological mechanisms drive disability. Methods: Brain-age analysis was applied to T1-weighted MRI images. Disability was assessed and peripheral blood was examined for CD8+CD57+ T-cell phenotypes. Linear regression models were used, adjusted for sex, age and normalized brain volume. Results: We included 179 mainly relapsing-remitting MS patients. A high brain-PAD was associated with high physical disability (mean brain-PAD = +6.54 [5.12–7.95]). CD8+CD57+(ILT2+PD-1+) T-cell frequency was neither associated with disability nor with brain-PAD. Physical disability was predicted by the interaction between brain-PAD and CD8+CD57+ILT2+PD-1+ T-cell frequency (AR2 = 0.196), yet without improvement compared to brain-PAD alone (AR2 = 0.206; AICc = 1.8). Conclusion: Higher frequency of CD8+CD57+ILT2+PD-1+ T-cells in the peripheral blood in patients with an older appearing brain was associated with worse disability scores, suggesting a role of these cells in the development of disability in MS patients with poorer brain health

In-room test results at CNAO of an innovative PT treatments online monitor (Dose Profiler)

The use of C, He and O ions as projectiles in Particle Therapy (PT) treatments is getting more and more widespread as a consequence of their enhanced relative biological effectiveness and oxygen enhancement ratio, when compared to the protons one. The advantages related to the incoming radiation improved efficacy are requiring an accurate online monitor of the dose release spatial distribution. Such monitor is necessary to prevent unwanted damage to the tissues surrounding the tumour that can arise, for example, due to morphological changes occurred in the patient during the treatment with respect to the initial CT scan. PT treatments with ions can be monitored by detecting the secondary radiation produced by the primary beam interactions with the patient body along the path towards the target volume. Charged fragments produced in the nuclear process of projectile fragmentation can be emitted at large angles with respect to the incoming beam direction and can be detected with high efficiency in a nearly background-free environment. The Dose Profiler (DP) detector, developed within the INSIDE project, is a scintillating fibre tracker that allows an online reconstruction and backtracking of such secondary charged fragments. The construction and preliminary in-room tests performed on the DP, carried out using the 12C ions beam of the CNAO treatment centre using an anthropomorphic phantom as a target, will be reviewed in this contribution. The impact of the secondary fragments interactions with the patient body will be discussed in view of a clinical application. Furthermore, the results implications for a pre-clinical trial on CNAO patients, foreseen in 2019, will be discussed

EAACI Task force Clinical epidemiology of anaphylaxis: experts’ perspective on the use of adrenaline autoinjectors in Europe

Background Worldwide, guidelines recommend the use of adrenaline autoinjectors (AAIs) for self-medication in patients who experience severe allergic reaction. The European Medical Agency recommends the prescription of two AAIs, which should be carried by patients at all times. The European Academy of Allergy and Clinical Immunology guidelines propose to prescribe a second AAI under some defined conditions. In the present study, we aimed to examine the adherence to these guidelines and prescription behavior of allergy experts regarding the number of AAIs prescribed for a given patient. Methods A standardized questionnaire was applied to the participants of the 5th International Conference of the Network of Online Registration for Anaphylaxis (NORA e. V.). Twenty-six experts (medical doctors with at least 2 years of experience in the field of anaphylaxis) answered the questions regarding the number of autoinjectors prescribed and the reasons influencing their decisions. Results Sixty-eight percent of the experts usually prescribed one AAI, while 32% prescribed two. The pediatricians and physicians with less experience tended to prescribe two autoinjectors more frequently. The experts were more likely to prescribe two adrenaline autoinjectors if the patient was a child, had a previous severe reaction, had mastocytosis, asthma, cardiovascular disease, or high body weight, or lived far from the emergency department. Conclusion Our data confirm the lack of consensus regarding the number of AAIs to prescribe. Despite the European Medical Agency recommendation, the majority of allergy experts prescribed one autoinjector per patient. However, under distinct circumstances (e.g. mastocytosis, asthma, excess body weight, a history of severe anaphylaxis, or restricted access to immediate emergency), experts tended to prescribe more AAIs, which is in accordance with the European Academy of Allergy and Clinical Immunology guidelines

The acute and long-term management of anaphylaxis: protocol for a systematic review

Background:The European Academy of Allergy and Clinical Immunology is in the process of developing its Guideline for Food Allergy and Anaphylaxis, and this systematic review is one of seven inter-linked evidence syntheses that are being undertaken in order to provide a state-of-the-art synopsis of the current evidence base in relation to epidemiology, prevention, diagnosis and clinical management and impact on quality of life, which will be used to inform clinical recommendations.The aims of this systematic review will be to assess the effectiveness of interventions for the acute management of anaphylaxis, and pharmacological and non-pharmacological approaches for the long-term management of anaphylaxis. Methods:A highly sensitive search strategy has been developed, and validated study design filters will be applied to retrieve all articles pertaining to the management of anaphylaxis from electronic bibliographic databases. We will systematically review the literature on the acute management of anaphylaxis by assessing the effectiveness of epinephrine, H1-antihistamines (versus placebo), systemic glucocorticosteroids, methylxanthines or any other treatments for the emergency management of people experiencing anaphylaxis. The main interventions that have been studied in the context of long-term management are anaphylaxis management plans and allergen-specific immunotherapy. Discussion:There is at present little in the way of robust evidence to guide decisions on the acute and/or long-term management of anaphylaxis. Given the risk of death and the considerable morbidity associated with anaphylaxis these evidence gaps need to be filled wherever possible; this systematic review will make a start in this area