136 research outputs found

    Ordinary differential equations described by their Lie symmetry algebra

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    The theory of Lie remarkable equations, i.e. differential equations characterized by their Lie point symmetries, is reviewed and applied to ordinary differential equations. In particular, we consider some relevant Lie algebras of vector fields on Rk\mathbb{R}^k and characterize Lie remarkable equations admitted by the considered Lie algebras.Comment: 17 page

    Geomorphological Environment: Dunes in Agrigento Coast

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    Geomorphological Environment:

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    La fascia costiera di San Leone (Agrigento-Siclia). è costituita da una spiaggia sabbiosa delimítala verso terra da un complesso dunale di particolare pregio. L'assetto geomorfologico di questo litorale è stato inlluenzato dal forte grado di antropizzazione del luogo. La fascia costiera nel tempo ha súbito degli avanzamenti e arreiramenti. Sono stati quindi analizzati e proposti alcuni rimedi. mirali alia ricostruzione. al mantenimenlo e alia diíesa della duna

    Identification of bolted joint properties through substructure decoupling

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    Substructure decoupling techniques, defined in the frame of Frequency Based Substructuring, allow to identify the dynamic behaviour of a structural subsystem starting from the known dynamics of the coupled system and from information about the remaining components. The problem of joint identification can be approached in the substructuring framework by decoupling jointed substructures from the assembled system. In this case, information about the coupling DoFs of the assembled structure is necessary and this could be a problem if the interface is inaccessible for measurements. Expansion techniques can be used to obtain the dynamics on inaccessible (interface) DoFs starting from accessible (internal) DoFs. A promising technique is the System Equivalent Model Mixing (SEMM) that combines numerical and experimental models of the same component to obtain a hybrid model. This technique has been already used in an iterative coupling–decoupling procedure to identify the linear dynamic behaviour of a joint, with a Virtual Point description of the interface. In this work, a similar identification procedure is applied to the Brake Reus Beam benchmark to identify the linear dynamic behaviour of a three bolted connection at low levels of excitation. The joint is considered as a third independent substructure that accounts for the mass and stiffness properties of the three bolts, thus avoiding singularity in the decoupling process. Instead of using the Virtual Point Transformation, the interface is modelled by performing a modal condensation on remote points allowing deformation of the connecting surfaces between subcomponents. The purpose of the study is to highlight numerical and ill-conditioning problems that may arise in this kind of identification

    Para- and perirenal ultrasonographic fat thickness is associated with 24-hours mean diastolic blood pressure levels in overweight and obese subjects

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    BACKGROUND: Renal sinus fat (RSF) has been recognized as a risk factor for arterial hypertension. This study was addressed to examine whether also para- and perirenal fat accumulation is associated to higher 24-h mean systolic (SBP) and/or diastolic blood pressure (DBP) levels in overweight and obese subjects. METHODS: A cohort of 42 overweight and obese patients, 29 women and 13 men, aged 25-55 years, not treated with any kind of drug, was examined. Body mass index (BMI), waist circumference (WC), fasting insulin and glucose serum levels, insulin resistance (assessed by using the homeostasis model assessment [HOMAIR]), and 24-h aldosterone urine levels were measured. Ambulatory blood pressure monitoring (ABPM) was measured with 15 min intervals from 7.0 a.m. to 11.0 a.m. and with 30 min intervals from 23.0 to 7.0 for consecutive 24 h, starting from 8:30 AM. Measurement of para- and perirenal fat thickness was performed by ultrasounds by a duplex Doppler apparatus. RESULTS: Para- and perirenal ultrasonographic fat thickness (PUFT) was significantly and positively correlated with WC (p < 0.01), insulin (p < 0.01), HOMAIR (p < 0.01), and 24-h mean DBP levels (p < 0.05). 24-h mean DBP was also significantly and positively correlated with 24-h aldosterone urine concentrations (p < 0.001). A multivariate analysis by multiple linear regression was performed; the final model showed that the association of 24-h mean DBP as dependent variable with PUFT (multiple R = 0.34; p = 0.026) and daily aldosterone production (multiple R = 0.59; p = 0.001) was independent of other anthropometric, hormone and metabolic parameters. DISCUSSION AND CONCLUSIONS: This study shows a positive independent association between PUFT and mean 24-h diastolic blood pressure levels in overweight and obese subjects, suggesting a possible direct role of PUFT in increasing daily diastolic blood pressure

    Physical Exercise and Quality of Life in Breast Cancer Survivors

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    An important goal for cancer patients is to improve the quality of life (QOL) by maximising functions affected by the disease and its therapy. Preliminary research suggests that exercise may be an effective intervention for enhancing QOL in cancer survivors. Research has provided preliminary evidence for the safety, feasibility, and efficacy of exercise training in breast cancer survivors. The aim of this study was to assess the association between physical exercise and quality of life in a population of female breast cancer survivors, followed up from diagnosis to the off-treatment time period, and investigated about their exercise habits in pre-diagnosis

    Nanovesicular Mediation of the Gut–Brain Axis by Probiotics: Insights into Irritable Bowel Syndrome

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    Background: Dysbiosis, influenced by poor diet or stress, is associated with various systemic diseases. Probiotic supplements are recognized for stabilizing gut microbiota and alleviating gastrointestinal issues, like irritable bowel syndrome (IBS). This study focused on the tryptophan pathways, which are important for the regulation of serotonin levels, and on host physiology and behavior regulation. Methods: Nanovesicles were isolated from the plasma of subjects with chronic diarrhea, both before and after 60 days of consuming a probiotic mix (Acronelle®, Bromatech S.r.l., Milan, Italy). These nanovesicles were assessed for the presence of Tryptophan 2,3-dioxygenase 2 (TDO 2). Furthermore, the probiotics mix, in combination with H2O2, was used to treat HT29 cells to explore its cytoprotective and anti-stress effect. Results: In vivo, levels of TDO 2 in nanovesicles were enhanced in the blood after probiotic treatment, suggesting a role in the gut–brain axis. In the in vitro model, a typical H2O2-induced stress effect occurred, which the probiotics mix was able to recover, showing a cytoprotective effect. The probiotics mix treatment significantly reduced the heat shock protein 60 kDa levels and was able to preserve intestinal integrity and barrier function by restoring the expression and redistribution of tight junction proteins. Moreover, the probiotics mix increased the expression of TDO 2 and serotonin receptors. Conclusions: This study provides evidence for the gut–brain axis mediation by nanovesicles, influencing central nervous system function

    First national analysis of severe obesity hospitalizations in Italy: insights from discharge card database

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    BackgroundObesity is associated with numerous severe diseases necessitating intensive healthcare for diagnosis and treatment. Most patients with obesity, especially in its severe form, require at least one hospitalization. However, few studies in Italy have assessed the burden of obesity on the National Health System. This study aims to routinely estimate the ‘disease burden’ by analyzing hospital admissions related to severe obesity.SubjectsWe analyzed the medical records of the Italian national hospital discharge database, including all patients older than 18 years discharged with the diagnosis of ‘severe obesity’.’ We included patients who underwent bariatric surgery, even without an explicit obesity code, such as laparoscopic restrictive gastric procedures, other stomach operations, and high gastric bypass. Special focus was given to those who underwent abdominal reshaping surgery. The cross-sectional survey PASSI in Italy served as an additional data source to estimate. The phenomenon was described using appropriate indicators, including rates and ratios between rates. Linear regression was employed to analyze trends in standardized rates over time.ResultsBetween 2014 and 2021, a total of 243,325 patients were discharged with a severe obesity code in Italy. Among these patients, 36.8% underwent at least one bariatric surgery procedure. We investigated the types of bariatric surgery procedures performed. The most frequent procedure was “other operations on the stomach,” where sleeve gastrectomy is included which also appears to be steadily increasing during the study period together with the gastric bypass, while the gastric bondage is decreasing over time.ConclusionThese findings underscore the significant burden of severe obesity on Italy’s healthcare system, a burden that is progressively increasing. The growing utilization of bariatric surgery suggests an escalating trend toward adopting drastic solutions to combat this health issue

    CD90+ liver cancer cells modulate endothelial cell phenotype through the release of exosomes containing H19 lncRNA.

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    BACKGROUND: CD90+ liver cancer cells have been described as cancer stem-cell-like (CSC), displaying aggressive and metastatic phenotype. Using two different in vitro models, already described as CD90+ liver cancer stem cells, our aim was to study their interaction with endothelial cells mediated by the release of exosomes. METHODS: Exosomes were isolated and characterized from both liver CD90+ cells and hepatoma cell lines. Endothelial cells were treated with exosomes, as well as transfected with a plasmid containing the full length sequence of the long non-coding RNA (lncRNA) H19. Molecular and functional analyses were done to characterize the endothelial phenotype after treatments. RESULTS: Exosomes released by CD90+ cancer cells, but not by parental hepatoma cells, modulated endothelial cells, promoting angiogenic phenotype and cell-to-cell adhesion. LncRNA profiling revealed that CD90+ cells were enriched in lncRNA H19, and released this through exosomes. Experiments of gain and loss of function of H19 showed that this LncRNA plays an important role in the exosome-mediated phenotype of endothelial cells. CONCLUSIONS: Our data indicate a new exosome-mediated mechanism by which CSC-like CD90+ cells could influence their tumor microenvironment by promoting angiogenesis. Moreover, we suggest the lncRNA H19 as a putative therapeutic target in hepatocellular carcinoma
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