Application of the Waveform Relaxation Technique to the Co-Simulation of Power Converter Controller and Electrical Circuit Models

In this paper we present the co-simulation of a PID class power converter controller and an electrical circuit by means of the waveform relaxation technique. The simulation of the controller model is characterized by a fixed-time stepping scheme reflecting its digital implementation, whereas a circuit simulation usually employs an adaptive time stepping scheme in order to account for a wide range of time constants within the circuit model. In order to maintain the characteristic of both models as well as to facilitate model replacement, we treat them separately by means of input/output relations and propose an application of a waveform relaxation algorithm. Furthermore, the maximum and minimum number of iterations of the proposed algorithm are mathematically analyzed. The concept of controller/circuit coupling is illustrated by an example of the co-simulation of a PI power converter controller and a model of the main dipole circuit of the Large Hadron Collider

Possibility and probability: application examples and comparison of two different approaches to uncertainty evaluation

This paper proposes two interesting applications of the approach to uncertainty evaluation and representation in terms of Random-Fuzzy Variables. One covers the expression of the calibration uncertainty of gauge blocks, and one considers unknown temperature variations, with respect to temperature at calibration time, in expressing a voltmeter uncertainty. Both considered examples show that the proposed approach is more effective than the traditional GUM approach

LIVER STIFFNESS EVALUATION USING ACOUSTIC RADIATION FORCE IMPULSE ELASTOGRAPHY IN PEDIATRIC AND ADULT PATIENTS WITH CONGENITAL HEART DISEASE

Background: Hepatic complications are common in patients with congenital heart disease as a consequence of the primary cardiac defect or as a result of surgical palliation (e.g. Fontan procedure). Liver involvement represents a significant challenge and an adequate hepatic surveillance is fundamental. Liver biopsy represents the gold standard for diagnosis and staging of hepatic fibrosis but it’s an invasive procedure not suitable for a routine setting. Acoustic radiation force impulse (ARFI) elastography is a recently developed technique that allows to assess hepatic stiffness in a non-invasive and reproducible way. The usefulness of ARFI imaging has been described in adult Fontan patients but only few studies have been reported in the pediatric Fontan population and no one in CHD others than Fontan. Aim: The aims of this study were to assess liver stiffness, using ElastPQTM acoustic radiation force impulse elastography, in pediatric and adult patients with CHD, to compare liver stiffness values with healthy controls and to analyze possible associations between ARFI values and clinical, biochemical, cardiac and hepatic parameters. Materials and methods: Pediatric and adult patients that underwent heart surgery for CHD and were followed at the Cardiology Unit of the “Azienda Ospedaliera Universitaria Integrata” of Verona between October 2018 and October 2020 were prospectively enrolled. Controls subjects without any liver or cardiac disease matched for age and sex to the case group were also included. The latest laboratory tests and echocardiogram available were collected. Liver ultrasound and ARFI measurement of liver stiffness were performed by a specifically trained single expert radiologist using the Philips Healtcare® ultrasound with ElastPQTM software. Results: A total of 50 subjects were enrolled for the study: 20 Fontan patients (13 males, median age at ARFI 8.4 years), 13 non-Fontan (9 males, median age at ARFI 4.8 years) and 17 controls (6 males, median age at ARFI 10 years). The median values of ARFI elastography were significantly higher in patients with CHDs (Fontan and non-Fontan patients) compared to control subjects (p<0.01). Patients with morphological right ventricle overload showed significantly higher results (p=0.02). The cut-off of 5.7 kPa at elastography was used to discriminate between normal liver and liver with signs of congestion or fibrosis. All controls subjects showed ARFI values <5.7 kPa whereas only 25% of Fontan patients and 46% of non-Fontan were below that threshold. Liver stiffness values were positively correlated with time from surgery and age at liver evaluation (p<0.01). The number of platelets and white blood cells were inversely related to liver stiffness measurements (p=0.04 and p=0.05 respectively). The AST to platelet ratio index positively correlated with ARFI elastography results (p<0.03). No significant correlations between ARFI results and other biochemical or cardiac parameters were found. Conclusions: Our data showed that the median values of liver stiffness measured with ElastPQTM pSWE were significantly higher in patients with CHDs compared to control subjects and, in particular, in those with morphological right ventricle overload. Liver stiffness values were also correlated with time from surgery and age at liver evaluation. The number of platelets and white blood cells were inversely related to liver stiffness measurements supporting the need of a screening for portal hypertension and splenomegaly in these patients. The AST to platelet ratio index was also correlated to ARFI elastography results suggesting that liver stiffness may reflect the evolution of liver fibrosis. In conclusion, our study demonstrated, for the first time in literature, that acoustic radiation force impulse elastography (pSWE) with ElastPQTM software can be a useful tool to assess liver stiffness in patients with Fontan circulation and other congenital heart disease

combination of measurement uncertainty contributions via the generalized dombi operator

Possibility is considered as a promising mathematical tool to represent that particular case of incomplete information given by a measurement result. A measurement result can be affected by systematic and random effects. The combination of random contributions in the possibility theory returns only approximated results, and it is important to identify an optimal combination method to obtain acceptable uncertainty evaluations. This paper considers the generalized Dombi operator as a promising tool to obtain satisfying results

Arterial tortuosity syndrome in two Italian paediatric patients

<p>Abstract</p> <p>Background</p> <p>Arterial tortuosity syndrome (ATS) (OMIM #208050) is a rare autosomal recessive connective tissue disorder characterized by tortuosity and elongation of the large and medium-sized arteries, propensity to aneurysms formation, vascular dissection, and pulmonary arteries stenosis. ATS is caused by mutations in <it>SLC2A10 </it>gene, encoding for the facilitative glucose transporter 10 (GLUT10). So far, 17 <it>SLC2A10 </it>mutations have been reported in 32 families, two of which were Italian with a total of five patients. Here we present the clinical and molecular characterization of two novel Italian paediatric ATS patients.</p> <p>Methods</p> <p>The exons and intronic flanking regions of <it>SLC2A10 </it>gene were amplified and direct sequencing was performed.</p> <p>Results</p> <p>In both patients, the involvement of major- and medium-sized arteries was characteristic; the nonvascular connective tissue manifestations were mild and not pathognomic of the disorder. Both patients, born from non-consanguineous parents, were heterozygous for two different <it>SLC2A10 </it>mutations, three of which were recurrent and one was novel (p.Arg231Trp). This mutation is localized at the endofacial loop between the transmembrane domains 6 and 7 of GLUT10.</p> <p>Conclusion</p> <p>Two novel ATS patients were characterized at clinical and molecular level. Overall, four ATS unrelated families are known in Italy so far. Though ATS clinical delineation improved in the last years, further works in the comprehension of disease presentation and complications onset, particularly in paediatric age, and on ATS molecular basis are needed to add new insights for diagnosis and prevention strategies for related complications.</p

Sodium Nitroprusside Toxicity in a Young Infant Following Cardiac Surgery

Adverse effects associated with sodium nitroprusside (SNP) administration are rarely observed in children. Monitoring of metabolic changes appears to be the most sensitive and accurate indicator of early toxicity. We report a case of acute toxicity in a 3-month-old boy treated with high-dose SNP infusion for systemic hypertension after elective coarctectomy, who developed seizures and severe lactic acidosis. We suggest blood lactate levels and base excess levels should be carefully monitored during SNP treatment in children, in order to detect early signs of toxicity, particularly when using high infusion rates

Towards a Muon Collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Erratum: Towards a muon collider

The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected