9 research outputs found

    Multi-Scale Modeling of Microstructure Evolution during Multi-Pass Hot-Rolling and Cooling Process

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    In this work, a 6-pass hot-rolling process followed by air cooling is studied by means of a coupled multi-scale simulation approach. The finite element method (FEM) is utilized to obtain macroscale thermomechanical parameters including temperature and strain rate. The microstructure evolution during the recrystallization and austenite (γ) to ferrite (α) transformation is simulated by a mesoscale cellular automaton (CA) model. The solute drag effect is included in the CA model to take into account the influence of manganese on the γ/α interface migration. The driving force for α-phase nucleation and growth also involves the contribution of the deformation stored energy inherited from hot-rolling. The simulation renders a clear visualization of the evolving grain structure during a multi-pass hot-rolling process. The variations of the nonuniform, deformation-stored energy field and carbon concentration field are also reproduced. A detailed analysis demonstrates how the parameters, including strain rate, grain size, temperature, and inter-pass time, influence the different mechanisms of recrystallization. Grain refinement induced by recrystallization and the γ→α phase transformation is also quantified. The simulated final α-fraction and the average α-grain size agree reasonably well with the experimental microstructure

    Muscle wasting in patients with chronic heart failure: results from the studies investigating co-morbidities aggravating heart failure (SICA-HF)

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    Aims To assess the prevalence and clinical impact of reductions in the skeletal muscle mass of patients with chronic heart failure (HF). Chronic HF is accompanied by co-morbidities that influence the quality of life and outcomes. Methods and results We prospectively enrolled 200 patients with chronic HF. The appendicular skeletal muscle mass of the arms and the legs combined, was assessed by dual energy X-ray absorptiometry. We analysed the muscle strength in arms and legs, and all patients underwent a 6-min walk test, a 4-m walk test, and spiroergometry testing. Muscle wasting was defined as the appendicular muscle mass 2 SD below the mean of a healthy reference group of adults aged 18–40 years, as suggested for the diagnosis of muscle wasting in healthy ageing (sarcopenia). Muscle wasting was detected in 39 (19.5%) subjects. Patients with muscle wasting had significantly lower values for handgrip and quadriceps strength as well as lower total peak oxygen consumption (peakVO2, 1173 ± 433 vs. 1622 ± 456 mL/min), lower exercise time (7.7 ± 3.8 vs. 10.22 ± 3.0 min, both P < 0.001), and lower left ventricular ejection fraction (LVEF, P = 0.05) than patients without. The distance walked during 6 min and the gait speed during the 4-m walk were lower in patients with muscle wasting (both P < 0.05). Serum levels of interleukin-6 were significantly elevated in patients with muscle wasting (P = 0.001). Logistic regression showed muscle wasting to be independently associated with reduced peak VO2 adjusted for age, sex, New York Heart Association class, haemoglobin, LVEF, distance walked in 6 minutes, and the number of co-morbidities (odds ratio 6.53, p = 0.01). Conclusion Muscle wasting is a frequent co-morbidity among patients with chronic HF. Patients with muscle wasting present with reduced exercise capacity and muscle strength, and advanced disease

    New Evidence for Therapies in Stroke Rehabilitation

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    Neurologic rehabilitation aims to reduce impairments and disabilities so that persons with serious stroke can return to participation in usual self-care and daily activities as independently as feasible. New strategies to enhance recovery draw from a growing understanding of how types of training, progressive task-related practice of skills, exercise for strengthening and fitness, neurostimulation, and drug and biological manipulations can induce adaptations at multiple levels of the nervous system. Recent clinical trials provide evidence for a range of new interventions to manage walking, reach and grasp, aphasia, visual field loss, and hemi-inattention

    Answer ALS, a large-scale resource for sporadic and familial ALS combining clinical and multi-omics data from induced pluripotent cell lines.

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    Answer ALS is a biological and clinical resource of patient-derived, induced pluripotent stem (iPS) cell lines, multi-omic data derived from iPS neurons and longitudinal clinical and smartphone data from over 1,000 patients with ALS. This resource provides population-level biological and clinical data that may be employed to identify clinical-molecular-biochemical subtypes of amyotrophic lateral sclerosis (ALS). A unique smartphone-based system was employed to collect deep clinical data, including fine motor activity, speech, breathing and linguistics/cognition. The iPS spinal neurons were blood derived from each patient and these cells underwent multi-omic analytics including whole-genome sequencing, RNA transcriptomics, ATAC-sequencing and proteomics. The intent of these data is for the generation of integrated clinical and biological signatures using bioinformatics, statistics and computational biology to establish patterns that may lead to a better understanding of the underlying mechanisms of disease, including subgroup identification. A web portal for open-source sharing of all data was developed for widespread community-based data analytics
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