Multiaxial damage assessment and life estimation: Application to an automotive exhaust manifold

AbstractSome mechanical components are subjected to thermo-mechanical fatigue, which occurs when both thermal and mechanical loads vary with time. Due to the complexity of the components geometry, stresses and strains field becomes multiaxial, worsening the fatigue resistance. In this paper several damage models are applied and compared on a case study, an automotive exhaust manifold simulacrum replying the material and the geometrical features of the commercial component. A complete thermo-structural FE analysis has been run and results have been post-processed by means of a numerical code implementing several multiaxial damage models available in literature and based both on a critical plane approach (Kandil-Brown-Miller, Fatemi-Socie) and strain-based models (Von Mises, ASME Code and Sonsino-Grubisic). The model calibration has been carried out by means of literature experimental data referred to commercial exhaust manifolds of similar geometry and material

Node detection using high-dimensional fuzzy parcellation applied to the insular cortex

Several functional connectivity approaches require the definition of a set of regions of interest (ROIs) that act as network nodes. Different methods have been developed to define these nodes and to derive their functional and effective connections, most of which are rather complex. Here we aim to propose a relatively simple “one-step” border detection and ROI estimation procedure employing the fuzzy c-mean clustering algorithm. To test this procedure and to explore insular connectivity beyond the two/three-region model currently proposed in the literature, we parcellated the insular cortex of 20 healthy right-handed volunteers scanned in a resting state. By employing a high-dimensional functional connectivity-based clustering process, we confirmed the two patterns of connectivity previously described. This method revealed a complex pattern of functional connectivity where the two previously detected insular clusters are subdivided into several other networks, some of which are not commonly associated with the insular cortex, such as the default mode network and parts of the dorsal attentional network. Furthermore, the detection of nodes was reliable, as demonstrated by the confirmative analysis performed on a replication group of subjects

Deep Vein Thrombosis and Pulmonary Embolism: Two Complications of COVID-19 Pneumonia?

Coronavirus disease 19 (COVID-19) is a worldwide infection which was recently declared a global health emergency by the WHO Emergency Committee. The most common symptoms are fever and cough, which can progress to pneumonia, acute respiratory distress syndrome (ARDS) and/or end-organ failure. Risk factors associated with ARDS and death are older age, comorbidities (e.g., hypertension, diabetes, hyperlipidaemia), neutrophilia, and organ and coagulation dysfunction. Disseminated intravascular coagulation and coagulopathy can contribute to death. Anticoagulant treatment is associated with decreased mortality in severe COVID-19 pneumonia. In this report we describe two patients with COVID-19 pneumonia who developed venous thromboembolism

A pectin-honey hydrogel prevents postoperative intraperitoneal adhesions in a rat model.

BACKGROUND: Adhesions are a common postoperative surgical complication. Liquid honey has been used intraperitoneally to reduce the incidence of these adhesions. However, solid barriers are considered more effective than liquids in decreasing postoperative intra-abdominal adhesion formation; therefore, a new pectin-honey hydrogel (PHH) was produced and its effectiveness was evaluated in a rat cecal abrasion model. Standardized cecal/peritoneal abrasion was performed through laparotomy in 48 adult Sprague-Dawley rats to induce peritoneal adhesion formation. Rats were randomly assigned to a control (C) and treatment (T) group. In group T, PHHs were placed between the injured peritoneum and cecum. Animals were euthanized on day 15 after surgery. Adhesions were evaluated macroscopically and adhesion scores were recorded and compared between the two groups. Inflammation, fibrosis, and neovascularization were histologically graded and compared between the groups. RESULTS: In group C, 17 of 24 (70.8%) animals developed adhesions between the cecum and peritoneum, while in group T only 5 of 24 (20.8%) did (p = 0.0012). In group C, one rat had an adhesion score of 3, sixteen had scores of 2, and seven rats had scores of 0. In group T, four rats had adhesion scores of 2, one rat had an adhesion score of 1 and nineteen have score 0 (p = 0.0003). Significantly lower grades of inflammation, fibrosis, and neovascularization were seen in group T (p = 0.006, p = 0.001, p = 0.002, respectively). CONCLUSION: PHH is a novel absorbable barrier that is effective in preventing intra-abdominal adhesions in a cecal abrasion model in rats. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-017-0965-z) contains supplementary material, which is available to authorized users

Abdominal Pain: A Real Challenge in Novel COVID-19 Infection

COVID-19 (coronavirus disease 19) is an infectious disease caused by coronavirus SARS-CoV-2. Since its detection in China at the end of 2019, the novel coronavirus has rapidly spread throughout the world and has caused an international public health emergency. The most common manifestation is flu-like symptoms. Mild infections usually improve within a few days, but COVID-19 can cause severe pneumonia with acute respiratory distress syndrome and death. Gastrointestinal symptoms are less common but possible and more difficult to recognize as part of a COVID-19 syndrome. In line with the current opinion of the WHO, we strongly believe that preventive measures and early diagnosis of COVID-19 are crucial to interrupt virus spread and avoid local outbreaks. We report the cases of COVID-19 patients admitted to our Emergency Department who complained of gastrointestinal symptoms at admission