608 research outputs found
Screening of Rayleigh Waves by Open Trenches
This paper presents results of a numerical study on the effectiveness of open trenches in reducing the ground vibration caused by propagating Rayleigh waves. The analysis is performed in the frequency domain and under conditions of plane strain using the Boundary Element Method. The soil is modelled as a homogeneous isotropic linear elastic half space. In order to represent the screening effect due to the installation of the barrier, the index ER is introduced. ER is defined as the ratio of the rate of energy transmission over the area to be protected in the presence of the trench and that without the trench. By means of ER, the influence of several parameters on the screening efficiency of the trench is investigated in some detail
Modeling and simulation of an emulsion copolymerization process
Radical emulsion copolymerization is one of the most widely diffused processes aimed to produce paints easy to use because of their low viscosity. At industrial scale, such processes require a high control level of all the operating variables. Particularly, the repeatability of an emulsion polymerization process within narrow limits is one of the most desirable features because it allows for controlling also other important product qualities as final solids content, average particle size, latex viscosity and polymer average molecular weight. Other important full plant requirements are the minimization of reactants dosing times and the preparation of a latex at the highest possible concentration. In this work, the first step of a complex industrial copolymerization process has been considered. Since different monomer types (butyl acrylate, styrene, acrylic acid and acrylamide) are involved, it has been necessary to propose a complete set of rate constants for all the traditional steps of the radical emulsion
reactions chain (i.e. initiation, propagation, radicals termination, backbiting and long-chain branching,
micelles seeding, etc..). These parameters have then been inserted into a system of ordinary differential
equations expressing all balances and control actions aimed to simulate the full plant synthesis. Finally, the proposed model has been experimentally validated through the comparison with a reaction calorimetry test carried out in an indirectly cooled semibatch reactor (RC1, 1L, Mettler Toledo). Obtained results have confirmed the reliability of the theoretical model
Integrated early warning surveillance. AchillesâČ heel of one health?
Emerging and re-emerging infectious diseases and zoonoses indicate the importance of the One Health (OH) approach for early warning. At present, even when surveillance data are available, they are infrequently timeously shared between the health sectors. In the context of the MediLabSecure (MLS) Project, we investigated the collection of a set of surveillance indicators able to provide data for the implementation of integrated early warning systems in the 22 MLS countries of the Mediterranean, Black Sea and Sahel regions. We used an online questionnaire (covering vector, human, and animal sectors), focusing on seven relevant arboviruses, that was submitted to 110 officially appointed experts. Results showed that West Nile virus was perceived as the most relevant zoonotic pathogen, while Dengue virus was the most relevant non-zoonotic pathogen in the study area. Data collection of early warning indicators is in place at a different level for all the investigated pathogens and in almost all the MLS Countries. Further assessments on the reliability of the collection in place and on the feasibility of piloting an integrated early warning system for arbovirus could verify if integrated early warning really represents the Achillesâ heel of OH
Non-Markovian decay and dynamics of decoherence in private and public environments
We study the decay process in an open system, emphasizing on the relevance of
the environment's spectral structure. Non-Markovian effects are included to
quantitatively analyze the degradation rate of the coherent evolution. The way
in which a two level system is coupled to different environments is
specifically addressed: multiple connections to a single bath (public
environment)or single connections to multiple baths (private environments). We
numerically evaluate the decay rate of a local excitation by using the Survival
Probability and the Loschmidt Echo. These rates are compared to analytical
results obtained from the standard Fermi Golden Rule (FGR) in Wide Band
Approximation, and a Self-Consistent evaluation that accounts for the bath's
memory in cases where an exact analytical solution is possible. We observe that
the correlations appearing in a public bath introduce further deviations from
the FGR as compared with a private bath.Comment: 18 pages, 7 figures. Accepted for publication in Physical Review
Mavacamten has a differential impact on force generation in myofibrils from rabbit psoas and human cardiac muscle
Effects of systemic glucocorticosteroids on peripheral neutrophil functions in asthmatic subjects: an ex vivo study
In 21 asthmatic subjects, several functions of isolated peripheral neutrophils (chemokinesis and chemotaxis toward 10% E. coli; superoxide anion generation after PMA; leukotriene B4 (LTB4) release from whole blood and isolated neutrophtls, before and after different stimuli) were evaluated during an acute exacerbation of asthma, and after 14 â 54 days of treatment with systemic glucocorticosteroids (GCS). During acute exacerbation, superoxide anion generation was higher in asthmatics than in eleven normal subjects (39.2 ± 14.1 vs. 25.2 ± 7.3 nmol, p < 0.05); there was a significant correlation between FEV1 (% of predicted) and neutrophil chemotaxis (r = â0.52, p = 0.04). After treatment, there was no significant change in all neutrophil functions, except for a decrease in neutrophil chemotaxis in subjects who showed an FEV1 increase > 20% after GCS treatment (from 131 ± 18 to 117 ± 21 ÎŒm, p = 0.005). Chemokinesis sicantly decreased in all subjects, and the changes significantly correlated with an arbitrary score of the total administered dose of GCS (r = 0.57, p < 0.05). These data suggest that neutrophil activation plays a minor role in asthma, and that treatment with GCS is not able to modify most functions of peripheral neutrophils in asthmatic subjects; chemotaxis seems to be related only to the severity of the asthma and it could reflect the improvement of the disease
EpiSouth: a network for communicable disease control in the Mediterranean region and the Balkans
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Giant inframuscular lipoma disclosed 14 years after a blunt trauma: A case report
<p>Abstract</p> <p>Introduction</p> <p>Lipoma is the most frequent benign tumor of the soft tissue. This lesion is often asymptomatic except in cases of enormous masses compressing nervous-vascular structures. Although the diagnosis is mostly clinical, imaging tools are useful to confirm the adipose nature of the lesion and to define its anatomic border. Sometimes, lipomas may be the result of a previous trauma, such as in this patient.</p> <p>Case presentation</p> <p>A 45-year-old man presented at our institution with a giant hard firm mass in the upper external quadrant of the right buttock disclosed after a weight loss diet. Subsequent magnetic resonance imaging showed a giant adipose mass developed beneath the large gluteal muscle and among the fibers of the medium and small gluteal muscles. When questioned on his medical history, the patient reported a blunt trauma of the lower back 14 years earlier. He underwent surgery and histological examination confirmed a giant lipoma.</p> <p>Conclusion</p> <p>Lipomas might result from a previous trauma. It is hypothesized that the trigger mechanism is activated by cytokine and growth factors released after the trauma. We herein present an exceptional case of a giant post-traumatic lipoma which caused a painful compression on the right sciatic nerve.</p
Zebrafish patient-derived xenografts identify chemo-response in pancreatic ductal adenocarcinoma patients
It is increasingly evident the necessity of new predictive tools for the treatment of pancreatic ductal adenocarcinoma in a personalized manner. We present a co-clinical trial testing the predic-tiveness of zPDX (zebrafish patient-derived xenograft) for assessing if patients could benefit from a therapeutic strategy (ClinicalTrials.gov: XenoZ, NCT03668418). zPDX are generated xenografting tumor tissues in zebrafish embryos. zPDX were exposed to chemotherapy regimens commonly used. We considered a zPDX a responder (R) when a decrease â„50% in the relative tumor area was reported; otherwise, we considered them a non-responder (NR). Patients were classified as Responder if their own zPDX was classified as an R for the chemotherapy scheme she/he received an adjuvant treatment; otherwise, we considered them a Non-Responder. We compared the cancer recurrence rate at 1 year after surgery and the disease-free survival (DFS) of patients of both groups. We reported a statistically significant higher recurrence rate in the Non-Responder group: 66.7% vs. 14.3% (p = 0.036), anticipating relapse/no relapse within 1 year after surgery in 12/16 patients. The mean DFS was longer in the R-group than the NR-group, even if not statistically significant: 19.2 months vs. 12.7 months, (p = 0.123). The proposed strategy could potentially improve preclinical evaluation of treatment modalities and may enable prospective therapeutic selection in everyday clinical practice
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