Search results for "STRESS"
showing 10 items of 6278 documents
Characterization and thermomechanical assessment of a SiC-sandwich material for Flow Channel Inserts in DCLL blankets
2019
Abstract Flow Channel Inserts (FCIs) are key elements in the high-temperature Dual Coolant Lead Lithium (DCLL) blanket, since they insulate electrically the flowing PbLi to avoid MHD effects and protect the steel structure from the hot liquid metal. SiC-based materials are main candidates for high-temperature FCIs, being a dense-porous SiC-based sandwich material an attractive option. The present work is focused on the development of such a SiC-based material. On the one hand, in order to assess the suitability of the concept for FCIs, the main results of a stress analysis, MHD and heat transfer simulations are summarized. On the other hand, the experimental production of the SiC-based mate…
Thermal-hydraulic and thermo-mechanical simulations of Water-Heavy Liquid Metal interactions towards the DEMO WCLL breeding blanket design
2019
Abstract The Water-Cooled Lithium Lead breeding blanket concept foresees the eutectic lithium-lead (Pb-15.7Li) alloy being cooled by pressurized sub-cooled water (temperature 295–328 °C; pressure 15.5 MPa) flowing in double wall tubes. Therefore, the interaction between the Pb-15.7Li and water (e.g. tube rupture) represents one of the main safety concerns for the design and safety analysis. Available LIFUS5/Mod2 experimental data are employed to assess the performances of thermal-hydraulic and thermo-mechanic codes. Thermal-hydraulic simulations, by SIMMER-III code, are focused on the prediction of the thermodynamic interaction among the fluids. ABAQUS Finite Element code, used for the desi…
Cirrhotic patients with minimal hepatic encephalopathy have increased capacity to eliminate superoxide and peroxynitrite in lymphocytes, associated w…
2018
Patients with minimal hepatic encephalopathy (MHE) show increased oxidative stress in blood. We aimed to assess whether MHE patients show alterations in different types of blood cells in (a) basal reactive oxygen and nitrogen species levels; (b) capacity to metabolise these species. To assess the mechanisms involved in the altered capacity to metabolise these species we also analysed: (c) peroxynitrite formation and d) peroxynitrite reaction with biological molecules. Levels of reactive oxygen and nitrogen species were measured by flow cytometry in blood cell populations from cirrhotic patients with and without MHE and controls, under basal conditions and after adding generators of superoxi…
A New Sampling Method for Spleen Stiffness Measurement Based on Quantitative Acoustic Radiation Force Impulse Elastography for Noninvasive Assessment…
2014
In our study, we evaluated the feasibility of a new sampling method for splenic stiffness (SS) measurement by Quantitative Acoustic Radiation Force Impulse Elastography (Virtual Touch Tissue Quantification (VTTQ)).We measured SS in 54 patients with HCV-related cirrhosis of whom 28 with esophageal varices (EV), 27 with Chronic Hepatitis C (CHC) F1–F3, and 63 healthy controls. VTTQ-SS was significantly higher among cirrhotic patients with EV (3.37 m/s) in comparison with controls (2.19 m/s,P<0.001), CHC patients (2.37 m/s,P<0.001), and cirrhotic patients without EV (2.7 m/s,P<0.001). Moreover, VTTQ-SS was significantly higher among cirrhotic patients without EV in comparison with bot…
Hepatitis C virus eradication by direct antiviral agents abates oxidative stress in patients with advanced liver fibrosis
2020
Background and aims: HCV eradication improves non-hepatic outcomes such as cardiovascular diseases, although without clearly defined mechanisms. In this study we aimed to assess whether improvement of carotid atherosclerosis may be linked to a reduction in systemic oxidative stress after viral clearance. Methods: We studied a retrospective cohort of 105 patients (age 62.4 ± 11.2 years; 62 men) with F3/F4 fibrosis, characterized by carotid ultrasonography at baseline and at sustained virologic response (SVR) follow-up. Levels of 8-iso-prostaglandin F2α (F2-isoprostanes) and other oxidative stress markers were measured on frozen sera. Association between change (denoted as Δ) in oxidative str…
The lipid lowering drug lovastatin protects against doxorubicin-induced hepatotoxicity.
2012
Liver is the main detoxifying organ and therefore the target of high concentrations of genotoxic compounds, such as environmental carcinogens and anticancer drugs. Here, we investigated the usefulness of lovastatin, which is nowadays widely used for lipid lowering purpose, as a hepatoprotective drug following the administration of the anthracycline derivative doxorubicin in vivo. To this end, BALB/c mice were exposed to either a single high dose or three consecutive low doses of doxorubicin. Acute and subacute hepatotoxicities were analyzed with or without lovastatin co-treatment. Lovastatin protected the liver against doxorubicin-induced acute pro-inflammatory and pro-fibrotic stress respo…
Mitochondrial oxidative injury: a key player in nonalcoholic fatty liver disease.
2020
Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease worldwide. NAFLD is tightly linked to the metabolic syndrome, insulin resistance, and oxidative stress. Globally, its inflammatory form, nonalcoholic steatohepatitis (NASH), has become the main cause of liver-related morbidity and mortality, mainly due to liver cirrhosis and primary liver cancer. One hallmark of NASH is the presence of changes in mitochondrial morphology and function that are accompanied by a blocked flow of electrons in the respiratory chain, which increases formation of mitochondrial reactive oxygen species in a self-perpetuating vicious cycle. Consequences are oxidation of DNA bases and …
Changes in glucose transporter expression and nitric oxide production are associated with liver injury in diabetes
2015
In diabetes mellitus (DM), both hyperglycaemia and hyperlipidaemia can initiate accumulation of fat in the liver, which might be further mediated by inducible nitric oxide synthase. We have studied changes in GLUT1, nitric oxide (NO(·)) concentration and liver damage in two rat DM models. STZ model was induced by strepozotocin 50 mg/kg. HS model was induced by high-fat diet and 30 mg/kg streptozotocin. GLUT1 expression was studied by means of real-time RT-PCR and immunohistochemistry. Production of NO(·) was monitored by means of erythrocyte sedimentation rate spectroscopy of Fe-DETC-NO complex. Liver damage was assessed using histological activity index (HAI). NO(·) concentration was incre…
A Numerical Approach to Finite Journal Bearings Lubricated With Ferrofluid
1987
Several cases of cylindrical bearings lubricated with ferrofluid are examined by means of a finite-difference numerical procedure. The subregion of cavitation is determined by imposing mass conservation across the “rupture” and “reformation” boundaries of the complete film. The examined cases refer to bearings confined by sealing rings formed by the lubricant itself, for which there is no need of external supply. In each case the most significant parameters are calculated and it is possible to see that the use of these bearings is favorable when speeds are low, clearances large, and loads light, because in such conditions the magnetic effects are comparable with the pure hydrodynamic ones a…
Anterior/Apical single incision mesh (Elevate™): Surgical experience, anatomical and functional results, and long-term complications
2021
Abstract Objective Pelvic organ prolapse is a common condition among post-menopausal women, and surgery is often the standard treatment proposed. Native tissue vaginal surgery is burdened by a high rate of recurrence, and mesh vaginal surgery has become current practice. The purpose of this study was to evaluate the safety and the effectiveness of the vaginal kit Anterior/Apical single incision mesh Elevate™ for the correction of anterior and apical compartment prolapse. Study design Data of patients with symptomatic anterior vaginal prolapse stage ≥ II, receiving mesh repair with the Anterior/Apical Elevate single incision system between January 2010 and January 2015 were retrieved. Prolap…