46 research outputs found

    Multiscale thermo-mechanical analysis of multi-layered coatings in solar thermal applications

    Get PDF
    Solar selective coatings can be multi-layered materials that optimize the solar absorption while reducing thermal radiation losses, granting the material long-term stability. These layers are deposited on structural materials (e.g., stainless steel, Inconel) in order to enhance the optical and thermal properties of the heat transfer system. However, interesting questions regarding their mechanical stability arise when operating at high temperatures. In this work, a full thermo-mechanical multiscale methodology is presented, covering the nano-, micro-, and macroscopic scales. In such methodology, fundamental material properties are determined by means of molecular dynamics simulations that are consequently implemented at the microstructural level by means of finite element analyses. On the other hand, the macroscale problem is solved while taking into account the effect of the microstructure via thermo-mechanical homogenization on a representative volume element (RVE). The methodology presented herein has been successfully implemented in a reference problem in concentrating solar power plants, namely the characterization of a carbon-based nanocomposite and the obtained results are in agreement with the expected theoretical values, demonstrating that it is now possible to apply successfully the concepts behind Integrated Computational Materials Engineering to design new coatings for complex realistic thermo-mechanical applications

    Autochthonous cases of mucosal leishmaniasis in Northeastern Italy: clinical management and novel treatment approaches

    Get PDF
    Mucosal leishmaniasis (ML) is a rare clinical variant of tegumentary leishmaniasis in Mediterranean Europe. Here we report on three autochthonous cases of head and neck ML in patients living in Northeastern Italy. Patients presented with non-specific, long-standing symptoms of upper respiratory tract involvement, mimicking other diseases. Parasitological diagnosis was reached by histopathology, immunohistochemistry and molecular biology on tissue specimens. Leishmania infantum was identified by molecular typing in all three cases. All patients reached a complete remission with protracted multivalent antileishmanial drugs; in one case, a novel approach of combined medical and endoscopic surgical treatment was carried out. High clinical suspicion led to a prompt diagnosis and deployment of a multivalent treatment. ML should be considered in the differential diagnosis of nasal, oral, and pharyngolaryngeal lesions in endemic areas. A prompt diagnosis is mandatory to establish a correct management; different antileishmanial medications as well as endoscopic surgical options may be required to reach a complete remission

    Acute diverticulitis in immunocompromised patients: evidence from an international multicenter observational registry (Web-based International Register of Emergency Surgery and Trauma, Wires-T)

    Get PDF
    Background: Immunocompromised patients with acute diverticulitis are at increased risk of morbidity and mortality. The aim of this study was to compare clinical presentations, types of treatment, and outcomes between immunocompromised and immunocompetent patients with acute diverticulitis. Methods: We compared the data of patients with acute diverticulitis extracted from the Web-based International Registry of Emergency Surgery and Trauma (WIRES-T) from January 2018 to December 2021. First, two groups were identified: medical therapy (A) and surgical therapy (B). Each group was divided into three subgroups: nonimmunocompromised (grade 0), mildly to moderately (grade 1), and severely immunocompromised (grade 2). Results: Data from 482 patients were analyzed—229 patients (47.5%) [M:F = 1:1; median age: 60 (24–95) years] in group A and 253 patients (52.5%) [M:F = 1:1; median age: 71 (26–94) years] in group B. There was a significant difference between the two groups in grade distribution: 69.9% versus 38.3% for grade 0, 26.6% versus 51% for grade 1, and 3.5% versus 10.7% for grade 2 (p < 0.00001). In group A, severe sepsis (p = 0.027) was more common in higher grades of immunodeficiency. Patients with grade 2 needed longer hospitalization (p = 0.005). In group B, a similar condition was found in terms of severe sepsis (p = 0.002), quick Sequential Organ Failure Assessment score > 2 (p = 0.0002), and Mannheim Peritonitis Index (p = 0.010). A Hartmann’s procedure is mainly performed in grades 1–2 (p < 0.0001). Major complications increased significantly after a Hartmann’s procedure (p = 0.047). Mortality was higher in the immunocompromised patients (p = 0.002). Conclusions: Immunocompromised patients with acute diverticulitis present with a more severe clinical picture. When surgery is required, immunocompromised patients mainly undergo a Hartmann’s procedure. Postoperative morbidity and mortality are, however, higher in immunocompromised patients, who also require a longer hospital stay

    Dissociation of Motor Task-Induced Cortical Excitability and Pain Perception Changes in Healthy Volunteers

    Get PDF
    Background: There is evidence that interventions aiming at modulation of the motor cortex activity lead to pain reduction. In order to understand further the role of the motor cortex on pain modulation, we aimed to compare the behavioral (pressure pain threshold) and neurophysiological effects (transcranial magnetic stimulation (TMS) induced cortical excitability) across three different motor tasks. Methodology/Principal Findings Fifteen healthy male subjects were enrolled in this randomized, controlled, blinded, cross-over designed study. Three different tasks were tested including motor learning with and without visual feedback, and simple hand movements. Cortical excitability was assessed using single and paired-pulse TMS measures such as resting motor threshold (RMT), motor-evoked potential (MEP), intracortical facilitation (ICF), short intracortical inhibition (SICI), and cortical silent period (CSP). All tasks showed significant reduction in pain perception represented by an increase in pressure pain threshold compared to the control condition (untrained hand). ANOVA indicated a difference among the three tasks regarding motor cortex excitability change. There was a significant increase in motor cortex excitability (as indexed by MEP increase and CSP shortening) for the simple hand movements. Conclusions/Significance: Although different motor tasks involving motor learning with and without visual feedback and simple hand movements appear to change pain perception similarly, it is likely that the neural mechanisms might not be the same as evidenced by differential effects in motor cortex excitability induced by these tasks. In addition, TMS-indexed motor excitability measures are not likely good markers to index the effects of motor-based tasks on pain perception in healthy subjects as other neural networks besides primary motor cortex might be involved with pain modulation during motor training

    Time for a paradigm shift in shared decision-making in trauma and emergency surgery? Results from an international survey

    Get PDF
    Background: Shared decision-making (SDM) between clinicians and patients is one of the pillars of the modern patient-centric philosophy of care. This study aims to explore SDM in the discipline of trauma and emergency surgery, investigating its interpretation as well as the barriers and facilitators for its implementation among surgeons. Methods: Grounding on the literature on the topics of the understanding, barriers, and facilitators of SDM in trauma and emergency surgery, a survey was created by a multidisciplinary committee and endorsed by the World Society of Emergency Surgery (WSES). The survey was sent to all 917 WSES members, advertised through the society’s website, and shared on the society’s Twitter profile. Results: A total of 650 trauma and emergency surgeons from 71 countries in five continents participated in the initiative. Less than half of the surgeons understood SDM, and 30% still saw the value in exclusively engaging multidisciplinary provider teams without involving the patient. Several barriers to effectively partnering with the patient in the decision-making process were identified, such as the lack of time and the need to concentrate on making medical teams work smoothly. Discussion: Our investigation underlines how only a minority of trauma and emergency surgeons understand SDM, and perhaps, the value of SDM is not fully accepted in trauma and emergency situations. The inclusion of SDM practices in clinical guidelines may represent the most feasible and advocated solutions

    Atherosclerosis and Alzheimer - diseases with a common cause? Inflammation, oxysterols, vasculature

    Full text link

    Factors associated with vitamin D deficiency in HIV-1 infected patients on combination antiretroviral therapy: a case-control study.

    No full text
    The aim of our study was to assess risk factors associated with vitamin D deficiency among HIV-1-infected patients on combination antiretroviral therapy (cART). A retrospective, case-control study was conducted to assess risk factors associated with vitamin D deficiency among HIV-1-infected adults on stable cART. Vitamin D deficiency was defined as 25-OH vitamin D concentration <30 ng/mL. A total of 195 patients (77% males, mean age 49.2 years) were enrolled into the study: 98 subjects with vitamin D deficiency (cases) and 97 with normal vitamin D serum concentration (controls). The mean serum concentration + standard deviation (SD) of vitamin D was 18.2+6.7 ng/mL among cases and 39.6+13.4 ng/ mL among controls. Current cART including tenofovir disoproxil fumarate (TDF) (OR 1.65; 95% CI, 1.31 to 1.94), osteoporosis (OR 1.78; 95% CI, 1.25 to 2.09), males who have sex with males (MSM) risk category (OR 1.59; 95% CI, 1.19 to 2.21), chronic hepatitis C (OR 1.44; 95% CI, 1.17 to 1.86), previous or current cancer (OR 1.47; 95% CI, 1.13 to 1.79), metabolic syndrome (OR 2.57; 95% CI, 1.96 to 2.98), and hepatic steatosis (OR 1.59; 95% CI, 1.17 to 2.05) were significant associated with an increased risk of vitamin D deficiency. On the other hand, current CD4+ lymphocyte count >600 cells/mm3 and current HIV RNA <20 copies/mL were significantly associated with a lower risk of vitamin D deficiency. In our case-control study, vitamin D deficiency is associated with TDF exposure, osteoporosis, and metabolic disturbances

    A case of Leishmania infection with focal splanchnic involvement without systemic symptoms: a potential anti-inflammatory role for vitamin D

    No full text
    We report the case of a 59 year-old woman with persistent nausea, hyporexia, fatigue and mild abdominal discomfort. The patient was hospitalized upon suspicion of malignancy due to multiple hepatic and splenic nodules found on an abdominal ultrasound. Hypercalcemia emerged at initial diagnostic workup, which was considered secondary to iatrogenic vitamin D intoxication. After an adequate management of hypercalcemia and normalization of serum calcium level, all symptoms presented by the patient completely regressed. In order to characterize splanchnic lesions, several biochemistry, microbiology and radiological tests were performed, including two bioptic specimens of a focal hepatic lesion. Eventually, a diagnosis of leishmanial infection was made. The patient started a specific anti-leishmanial treatment, and the focal hepatic and splenic lesions progressively disappeared

    Serum bactericidal titres for monitoring antimicrobial therapy: current status and potential role in the management of multidrug-resistant Gram-negative infections

    No full text
    none8noBackground: Serum bactericidal titres (SBTs) were widely used in the 1970s and 1980s to monitor antimicrobial therapy but are now seldom recommended. It is the only laboratory test that integrates drug pharmacodynamics, host pharmacokinetics and synergistic or antagonistic interactions of antimicrobial combinations into a single index of antimicrobial activity. We hypothesized that SBTs could play a renewed role in monitoring antibiotic treatment of multidrug-resistant Gram-negative infections. However, the last critical appraisal of the test was published over 30 years ago. Objectives: This narrative review provides an updated assessment of the SBT test and its methodological limitations. We performed a diagnostic meta-analysis to estimate the value of SBTs for predicting clinical failure or death during antibiotic treatment. Sources: A comprehensive literature search of PubMed including all English publications was performed in December 2019 using the Medical Subject Headings (MeSH search terms “serum”, “bactericidal”, “inhibitory”, “titre”, “monitoring”, “anti-infective agents” “antimicrobial therapy” and “therapeutic drug monitoring”). Content: Although standardized methods for performing SBTs were approved in 1999, the test remains labour intensive, and results may not be available until 72 hr. However, the use of non-culture-based endpoints (i.e. spectrophotometric or fluorescent) may shorten test time to 24 hr. Despite considerable heterogeneity in published studies, a meta-analysis of 11 evaluable studies published from 1974 to 2007 indicated a critical SBT result (peak SBT ≤1:8 or trough ≤1:2) is associated with a diagnostic odds ratio for clinical failure during antibiotic treatment of 12.27 (95% confidence interval 5.28–28.54) and a 5.32 (95% 1.32–21.42) odds of death. Implications: SBTs have prognostic value for identifying patients at high risk for antibiotic treatment failure, but the slow turnaround time of the current test limits its clinical utility. Standardization of a more rapid SBT testing method is needed.mixedZaghi I.; Gaibani P.; Campoli C.; Bartoletti M.; Giannella M.; Ambretti S.; Viale P.; Lewis R.E.Zaghi I.; Gaibani P.; Campoli C.; Bartoletti M.; Giannella M.; Ambretti S.; Viale P.; Lewis R.E
    corecore