An upwind vertex centred Finite Volume solver for Lagrangian solid dynamics

A vertex centred Jameson–Schmidt–Turkel (JST) finite volume algorithm was recently introduced by the authors (Aguirre et al., 2014 [1]) in the context of fast solid isothermal dynamics. The spatial discretisation scheme was constructed upon a Lagrangian two-field mixed (linear momentum and the deformation gradient) formulation presented as a system of conservation laws [2], [3] and [4]. In this paper, the formulation is further enhanced by introducing a novel upwind vertex centred finite volume algorithm with three key novelties. First, a conservation law for the volume map is incorporated into the existing two-field system to extend the range of applications towards the incompressibility limit (Gil et al., 2014 [5]). Second, the use of a linearised Riemann solver and reconstruction limiters is derived for the stabilisation of the scheme together with an efficient edge-based implementation. Third, the treatment of thermo-mechanical processes through a Mie–Grüneisen equation of state is incorporated in the proposed formulation. For completeness, the study of the eigenvalue structure of the resulting system of conservation laws is carried out to demonstrate hyperbolicity and obtain the correct time step bounds for non-isothermal processes. A series of numerical examples are presented in order to assess the robustness of the proposed methodology. The overall scheme shows excellent behaviour in shock and bending dominated nearly incompressible scenarios without spurious pressure oscillations, yielding second order of convergence for both velocities and stresses

Observational study of HR+/HER2− metastatic breast cancer patients treated with abemaciclib in Spain in the Named Patient Use Program (AbemusS)

Metastatic breast cancer; Abemaciclib; EffectivenessCàncer de mama metastàtic; Abemaciclib; EficàciaCáncer de mama metastásico; Abemaciclib; EficaciaIntroduction/objectives To describe abemaciclib use in patients with hormone receptor-positive, human epidermal growth factor receptor-negative (HR+/HER2−) metastatic breast cancer (mBC) who participated in the Named Patient Use program (NPU) in Spain. Material and methods This retrospective study was based on medical record review of patients across 20 centers during 2018/2019. Patients were followed up until death, enrolment in a clinical trial, loss of follow-up or study end. Clinical and demographic characteristics, treatment patterns and abemaciclib effectiveness were analyzed; time-to-event and median times were estimated using the Kaplan–Meier (KM) method. Results The study included 69 female patients with mBC (mean age 60.4 ± 12.4 years), 86% of whom had an initial diagnosis of early BC and 20% had an ECOG ≥ 2. Median follow-up was 23 months (range 16–28). Metastases were frequently observed in bone (79%) and visceral tissue (65%), with 47% having metastases in > 2 sites. Median number of treatment lines before abemaciclib was 6 (range 1–10). Abemaciclib monotherapy was received by 72% of patients and combination therapy with endocrine therapy by 28% of patients; 54% of patients required dose adjustments, with a median time to first adjustment of 1.8 months. Abemaciclib was discontinued in 86% of patients after a median of 7.7 months (13.2 months for combination therapy and 7.0 months for monotherapy) mainly due to disease progression (69%). Conclusion These results suggest that abemaciclib is effective, as monotherapy and in combination, for patients with heavily pretreated mBC, consistent with clinical trial results.Sponsorship for this study was funded by Lilly. It was conducted with the support of the Clinical Research Organization IQVIA for the following activities: protocol development, site monitoring and statistical analysis

Escoliosis experimental por lesión vascular metamérica a nivel lumbar

Se ha realizado un estudio experimental en 25 híbridos de conejo californiano con conejo blanco gigante neozelandés de 37 ± 3 días, lesionando la vascularización metamé- rica que irriga las vértebras lumbares con el propósito de alterar indirectamente el desarrollo de los cartílagos neurocentrales (CNC). La lesión vascular se produjo por la destrucción unilateral a dos o tres niveles de los vasos metaméricos de las vértebras L3 a L5. Las columnas vertebrales fueron disecadas, realizándose estudios radiológicos, macroscópicos e histológicos. Se obtuvieron curvas escolióticas (13 ±4°) de convexidad hacia el lado contrario al intervenido, con rotación de los cuerpos vertebrales (12 ± 5o ) hacia la concavidad de la curva, y rectificación de la cifosis lumbar fisiológica de los conejos (5 ±7°). El ascpecto macroscópico de las curvas era similar al que se observa en la escoliosis idiopática humana. Estos hallazgos apoyan la idea de que una alteración del desarrollo del CNC por déficit vascular, de forma unilateral, es capaz de inducir la aparición de una escoliosis.We have damaged the vascular supply to the right neurocentral cartilage (NCC) to 25 growing rabbits, in order to induce scoliosis. The employed technique was the section of the right metameric artery and vein at two or three levels in the lumbar region (L3 to L5). The spine was studied histologically macroscopically and radiologically. We got slight curves (13 ±4°) with the convexity towards the opposite side to the operated zone, and with rotation (12 ±5°) and lordosis (5 ± 7°). These lesions are similar to human idiopathic scoliosis and may be explained because of the NCC's physiological properties. Those findings support the idea that any mechanic, metabolic or endocrine alteration that cause damage to the NCC or to its vascularization, unilaterally, will induced a scoliosis development

Comunicación intraventricular traumática

La corrección quirúrgica de defectos intracardíacos producidos por arma blanca o de fuego es una rareza en la literatura científica. Por esto, hemos considerado de interés presentar el siguiente caso, fiel reflejo de la problemática de los mismos

Plasma polyunsaturated fatty acid pattern in active inflammatory bowel disease

Plasma fatty acid patterns were assessed by gas liquid chromatography in 73 patients with active inflammatory bowel disease and 107 healthy controls. The influence of the disease activity on fatty acid profile was also investigated. Plasma fatty acid patterns in patients with ulcerative colitis and Crohn's disease were similar. Plasma C18:3n3 and C22:6n3 were significantly higher in active ulcerative colitis (p = 0.0143 and p < 0.00001 respectively) and in Crohn's disease (p < 0.00001 for both) than in controls, whereas C20:3n6 was significantly lower in patients than in controls, both in ulcerative colitis (p = 0.0001) and in Crohn's disease (p = 0.0041). In more severe disease, plasma polyunsaturated fatty acid concentrations fell with a significant stepwise decrease in the desaturation index (p = 0.0031 in ulcerative colitis and p = 0.0355 in Crohn's disease). Even in patients with severe disease, however, plasma n3 fatty acids (C18:3n3 and C22:6n3) never fell below those of healthy controls. These findings suggest that in active inflammatory bowel disease, an increased biosynthesis might coexist with an increased consumption of polyunsaturated fatty acids. These observations may be of relevance in the pathogenesis of the disease as polyunsaturated fatty acids are involved in tissue eicosanoid synthesis and cellular membrane function, including that of immunocompetent cells. These results also question the rationale of using n3 polyunsaturated fatty acids in the treatment of inflammatory bowel disease

Analysis of the electromagnetic radiation generated by a multipactor discharge occurring within a microwave passive component

International audienceMultipactoring is a non-linear phenomenon that appears in highpower microwave equipments operating under vacuum conditions and causes several undesirable effects. In this manuscript, a theoretical and experimental study of the RF spectrum radiated by a multipactor discharge, occurring within a realistic microwave component based on rectangular waveguides, is reported. The electromagnetic coupling of a multipactor current to the fundamental propagative mode of a uniform waveguide has been analyzed in the context of the microwave network theory. The discharge produced under a single-carrier RF voltage regime has been approached as a shunt current source exciting such a mode in a transmission-line gap-region. By means of a simple equivalent circuit, this model allows predicting the harmonics generated by the discharge occurring in a realistic passive waveguide component. Power spectrum radiated by a third order multipactor discharge has been measured in an E-plane silver-plated waveguide transformer, thus validating qualitatively the presented theory to simulate the noise generated by a single-carrier multipactor discharge

Physicochemical Properties of Lipoproteins Assessed by Nuclear Magnetic Resonance as a Predictor of Premature Cardiovascular Disease. PRESARV-SEA Study

Some lipoprotein disorders related to the residual risk of premature cardiovascular disease (PCVD) are not detected by the conventional lipid profile. In this case-control study, the predictive power of PCVD of serum sdLDL-C, measured using a lipoprotein precipitation method, and of the physicochemical properties of serum lipoproteins, analyzed by nuclear magnetic resonance (NMR) techniques, were evaluated. We studied a group of patients with a first PCVD event (n = 125) and a group of control subjects (n = 190). Conventional lipid profile, the size and number of Very Low Density Lipoproteins (VLDL), Low Density Lipoproteins (LDL), High Density Lipoproteins (HDL) particles, and the number of particles of their subclasses (large, medium, and small) were measured. Compared to controls, PCVD patients had lower concentrations of all LDL particles, and smaller and larger diameter of LDL and HDL particles, respectively. PCVD patients also showed higher concentrations of small dense LDL-cholesterol (sdLDL), and triglycerides (Tg) in LDL and HDL particles (HDL-Tg), and higher concentrations of large VLDL particles. Multivariate logistic regression showed that sdLDL-C, HDL-Tg, and large concentrations of LDL particles were the most powerful predictors of PCVD. A strong relationship was observed between increased HDL-Tg concentrations and PCVD. This study demonstrates that beyond the conventional lipid profile, PCVD patients have other atherogenic lipoprotein alterations that are detected by magnetic resonance imaging (MRI) analysis

A stabilised Petrov-Galerkin formulation for linear tetrahedral elements in compressible, nearly incompressible and truly incompressible fast dynamics

A mixed second order stabilised Petrov-Galerkin finite element framework was recently introduced by the authors (Lee et al., 2014) [46]. The new mixed formulation, written as a system of conservation laws for the linear momentum and the deformation gradient, performs extremely well in bending dominated scenarios (even when linear tetrahedral elements are used) yielding equal order of convergence for displacements and stresses. In this paper, this formulation is further enhanced for nearly and truly incompressible deformations with three key novelties. First, a new conservation law for the Jacobian of the deformation is added into the system providing extra flexibility to the scheme. Second, a variationally consistent Petrov-Galerkin stabilisation methodology is derived. Third, an adapted fractional step method is presented for both incompressible and nearly incompressible materials in the context of nonlinear elastodynamics. For completeness and ease of understanding, these three improvements are presented both in small and large strain regimes, studying the eigenstructure of the resulting systems. A series of numerical examples are presented in order to demonstrate the robustness of the enhanced methodology with respect to the work previously published by the authors

A vertex centred Finite Volume Jameson-Schmidt-Turkel (JST) algorithm for a mixed conservation formulation in solid dynamics

A vertex centred Finite Volume algorithm is presented for the numerical simulation of fast transient dynamics problems involving large deformations. A mixed formulation based upon the use of the linear momentum, the deformation gradient tensor and the total energy as conservation variables is discretised in space using linear triangles and tetrahedra in two-dimensional and three-dimensional computations, respectively. The scheme is implemented using central differences for the evaluation of the interface fluxes in conjunction with the Jameson-Schmidt-Turkel (JST) artificial dissipation term. The discretisation in time is performed by using a Total Variational Diminishing (TVD) two-stage Runge-Kutta time integrator. The JST algorithm is adapted in order to ensure the preservation of linear and angular momenta. The framework results in a low order computationally efficient solver for solid dynamics, which proves to be very competitive in nearly incompressible scenarios and bending dominated applications

Improving interMediAte Risk management. MARK study

<p>Abstract</p> <p>Background</p> <p>Cardiovascular risk functions fail to identify more than 50% of patients who develop cardiovascular disease. This is especially evident in the intermediate-risk patients in which clinical management becomes difficult. Our purpose is to analyze if ankle-brachial index (ABI), measures of arterial stiffness, postprandial glucose, glycosylated hemoglobin, self-measured blood pressure and presence of comorbidity are independently associated to incidence of vascular events and whether they can improve the predictive capacity of current risk equations in the intermediate-risk population.</p> <p>Methods/Design</p> <p>This project involves 3 groups belonging to REDIAPP (RETICS RD06/0018) from 3 Spanish regions. We will recruit a multicenter cohort of 2688 patients at intermediate risk (coronary risk between 5 and 15% or vascular death risk between 3-5% over 10 years) and no history of atherosclerotic disease, selected at random. We will record socio-demographic data, information on diet, physical activity, comorbidity and intermittent claudication. We will measure ABI, pulse wave velocity and cardio ankle vascular index at rest and after a light intensity exercise. Blood pressure and anthropometric data will be also recorded. We will also quantify lipids, glucose and glycosylated hemoglobin in a fasting blood sample and postprandial capillary glucose. Eighteen months after the recruitment, patients will be followed up to determine the incidence of vascular events (later follow-ups are planned at 5 and 10 years). We will analyze whether the new proposed risk factors contribute to improve the risk functions based on classic risk factors.</p> <p>Discussion</p> <p>Primary prevention of cardiovascular diseases is a priority in public health policy of developed and developing countries. The fundamental strategy consists in identifying people in a high risk situation in which preventive measures are effective and efficient. Improvement of these predictions in our country will have an immediate, clinical and welfare impact and a short term public health effect.</p> <p>Trial Registration</p> <p>Clinical Trials.gov Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01428934">NCT01428934</a></p