20 research outputs found
Numerical Simulations of the flow field and chemical reactions of the Storage/Oxidation process within a NSC Pt - BaO Catalyst
A NOxStorage Catalyst (NSC) has been studied by means of reactive CFD simulations. In the scenario of automotive pollutant emission reduction, due to the stringent regulation, the detailed description of the chemical and physical phenomena within catalysts represents a key point in order to improve their conversion efficiency. The active part of the catalyst has been simulated as a porous medium. In this zone, surface reactions take place, which are modelled by means of an Arrhenius chemical kinetic approach, involving the Pt and BaO sites on the active surface of the matrix. Actually, two chemical mechanisms are considered, the simplest involves only BaO site, the other one includes both BaO and Ptsites. Both models are validated against data available in the literature and then applied to a real automotive catalyst geometry. Thus, a detailed description of the spatial distribution of the species is provided for both models. Lean condition is simulated in order to check the catalyst behaviour according to experimental results
Real-Life Clinical Data of Cabozantinib for Unresectable Hepatocellular Carcinoma
Introduction: Cabozantinib has been approved by the European Medicine Agency (EMA) for hepatocellular carcinoma (HCC) previously treated with sorafenib. Cabozantinib is also being tested in combination with immune checkpoint inhibitors in the frontline setting. Real-life clinical data of cabozantinib for HCC are still lacking. Moreover, the prognostic factors for HCC treated with cabozantinib have not been investigated. Methods: We evaluated clinical data and outcome of HCC patients who received cabozantinib in the legal context of named patient use in Italy. Results: Ninety-six patients from 15 centres received cabozantinib. All patients had preserved liver function (Child-Pugh A), mostly with an advanced HCC (77.1%) in a third-line setting (75.0%). The prevalence of performance status (PS) > 0, macrovascular invasion (MVI), extrahepatic spread, and alpha-fetoprotein (AFP) >400 ng/mL was 50.0, 30.2, 67.7, and 44.8%, respectively. Median overall survival (OS) and progression-free survival were 12.1 (95% confidence interval 9.4–14.8) and 5.1 (3.3–6.9) months, respectively. Most common treatment-related adverse events (AEs) were fatigue (67.7%), diarrhoea (54.2%), anorexia (45.8%), HFSR (43.8%), weight loss (24.0%), and hypertension (24.0%). Most common treatment-related Grade 3–4 AEs were fatigue (6.3%), HFSR (6.3%), and increased aminotransferases (6.3%). MVI, ECOG-PS > 0, and AFP >400 ng/mL predicted a worse OS. Discontinuation for intolerance and no new extrahepatic lesions at the progression were associated with better outcomes. Conclusions: In a real-life Western scenario (mostly in a third-line setting), cabozantinib efficacy and safety data were comparable with those reported in its registration trial. Data regarding the prognostic factors might help in patient selection and design of clinical trials
Three-dimensional analysis of flow-chemical interaction within a single square channel of a lean NOx trap catalyst
A fully 3D unsteady Computational Fluid Dynamics (CFD) approach coupled with heterogeneous reaction chemistry is presented in order to study the behavior of a single square channel as part of a Lean NOx Traps. The reliability of the numerical tool has been validated against literature data considering only active BaO site. Even though the input/output performance of such catalyst has been well known, here the spatial distribution within a single channel is investigated in details. The square channel geometry influences the flow field and the catalyst performance being the flow velocity distribution on the cross section non homogeneous. The mutual interaction between the flow and the active catalyst walls influences the spatial distribution of the volumetric species. Low velocity regions near the square corners and transversal secondary flows are shown in several cross-sections along the streamwise direction at different instants. The results shed light on the three-dimensional characteristic of both the flow field and species distribution within a single square channel of the catalyst with respect to 0-1D approaches
Numerical simulation of the flow field and chemical reactions within a NSC diesel catalyst
In the present work three-dimensional steady and unsteady numerical simulations of the flow field and chemical reactions within aNOx Storage Converter (NSC) diesel catalyst have been made. In the first part of the paper, only the flow characteristics within a catalyst have been investigated by mean of a steady three-dimensional Reynolds-Averaged Navier-Stokes approach and a transport equation for each of the incoming chemical species. For flow simulations, the catalyst volume has been split in three zones: inlet, catalytic monolith, treated as porous media, and outlet, medium. The results have been reported in three different working points. Evidences on how the non-uniform flow distribution affects the catalyst efficiency have been described. In the second part, the fluid-dynamic solver has been coupled with a chemical reaction mechanism in order to catch the chemical surface reaction within a NSC catalyst. This coupled model has been validated according to the literature. Volumetric and superficial species concentration have been calculated imposing the site density and the kinetic of the reactions on a substrate Ba/Al2O3. NOx spatial distributions within the catalyst during a dsorption phase are reported. The model represent a reliable tool to investigate in detail the complex flow/chemistry interaction within the modern diesel engine catalysts
Numerical Simulation of the Flow Field and Chemical Reactions within a NSC Diesel Catalyst
Pharmacological approach and adherence to treatment recommendations in frequently and non-frequently exacerbating COPD patients from Italy: MISTRAL - The prospective cohort, observational study
Background: Several documents and guidelines provide recommendations for effective management of COPD patients. However, there is often a significant imbalance between recommended treatment of COPD patients and the actual care provided both in primary care and specialty setting. This imbalance could result in a significant negative impact on patients\u2019 health status and quality of life, leading to increased hospitalisations and health resource utilisation in COPD patients Methods: MISTRAL was an observational, longitudinal, prospective cohort study, designed to assess the overall pharmacological approach of COPD in routine clinical practice in Italy. Eligible patients were divided into two cohorts based on their exacerbation history in the year prior to the enrolment, frequent exacerbators (FEs; 652 exacerbations), and non-frequent exacerbators (NFEs; 641 exacerbation). The primary objective was to assess adherence to Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 treatment recommendations in FEs and NFEs at baseline and follow-up visits Results: Of the 1489 enrolled patients, 1468 (98.6%; FEs, 526; NFEs, 942) were considered evaluable for analyses. At baseline, 57.8% of patients were treated according to GOLD 2011 recommendations; a greater proportion of FEs were treated according to GOLD recommendations, compared with NFEs patients at baseline (77.1% versus 46.7%; P < 0.0001), and all study visits. At baseline, GOLD group D patients were the most adherent (81.2%) to treatment recommendations, while group A patients were the least adherent (30.3%) at baseline, attributed mainly to overuse of inhaled corticosteroids in less severe GOLD groups. Triple therapy with long-acting muscarinic antagonist (LAMA) + long-acting \u3b22-agonist/inhaled corticosteroid (LABA/ICS) was the most frequent prescribed treatment at all study visits, irrespective of patient's exacerbation history. Changes in treatment were more frequent in FEs versus NFEs Conclusions: The Mistral study reports a scarce adherence to the GOLD 2011 treatment recommendations in routine clinical practice in Italy. The adherence was particularly low in less severe, non-frequent exacerbating patients mostly for ICS overuse, and was higher in high-risk, frequent exacerbating COPD patient
Numerical Simulations of the flow field and chemical reactions of the Storage/Oxidation process within a NSC Pt - BaO Catalyst
Conversion Chemotherapy for Technically Unresectable Colorectal Liver Metastases
The response rate of patients with unresectable liver-limited metastases of colorectal cancer can be improved by converting inoperable disease to operable disease. However, the benefits of conversion chemotherapy for survival are still controversial. Patients considered to have technically inoperable disease by a multidisciplinary team were retrospectively analyzed. Patients were stratified based on the treatment they received, into the chemotherapy only (G1), chemotherapy plus bevacizumab (G2), or chemotherapy plus cetuximab (G3) groups. The primary endpoint was the resection rate. The secondary endpoint was the overall survival (OS), according to both the treatment received and liver surgery status. In total, 104 patients were included: 30 in the G1, 39 in the G2, and 35 in the G3 groups. All G3 patients had the wild-Type KRAS exon 2. The surgical resection rates for patients in the G1, G2, and G3 groups were 43.3% (13/30), 30.7% (12/39), and 51.4% (18/35), respectively. Disease-free survival did not show significant differences among the 3 groups. The median OS was 35.2 months in the G1, 28.8 months in the G2, and 42.1 months in the G3 (P=0.25) groups. The OS was significantly higher in patients who underwent surgical resection than those who did not. The median OS was 28.4 months in patients who did not undergo resection, whereas it had not been reached after a median follow-up period of 37.5 months for patients who underwent surgical resection (events: 21/43). Our data confirmed that the conversion of initially inoperable disease to operable disease conferred a survival benefit, even in patients who relapsed after surgery. The addition of cetuximab to chemotherapy improved the objective response and resection rates, conferring a potential survival benefit even in patients whose diseases were not converted to operable disease, compared to chemotherapy alone or in combination with bevacizumab
The secretory senescence in otorhinolaryngology: principles of treatment
Atrophy or hypofunction of the salivary gland because of aging, radio-therapy or disease causes hyposalivation and impairs the quality of life of patients by compromising mastication, swallowing and speech and by leading to a loss of taste. Moreover, hyposalivation exacerbates dental caries and induces periodontal disease, and oral candidiasis. Currently, no satisfactory therapies have been established to solve salivary hypofunction. Current treatment options for atrophy or hypofunction of the salivary glands in clinical practice are only symptomatic and include saliva substitutes and parasympathetic agonists, such as pilocarpine, to stimulate salivary flow. However, parasympathomimetics have systemic side effects, so different treatment options are necessary, and
research has recently focused on this. The main strategies that have been proposed to restore salivary gland atrophy and hypofunction are gene therapy by gene activation/silencing during stem cell differentiation and by the use of viral vectors, such as adenoviruses; cell-based therapy with salivary gland cells, stem cells and non-salivary gland and/or non-epithelial cells to regenerate damaged salivary gland cells; replacement with tissue bioengineering in which organoids from pluripotent stem cells are used in the development of organ replacement regenerative therapy. Remarkable progression in this research field has been made in the last decade, but a definitive therapy for salivary gland hypofunction has not been developed due to intrinsic challenges that
come with each approach. However, with research efforts in the future, a range of precision medicine therapies may become available individualized to each patient
The role of PNI to predict survival in advanced hepatocellular carcinoma treated with Sorafenib.
BACKGROUND AND AIMS:The present study aims to investigate the role of the prognostic nutritional index (PNI) on survival in patients with advanced hepatocellular carcinoma (HCC) treated with sorafenib. METHODS:This multicentric study included a training cohort of 194 HCC patients and three external validation cohorts of 129, 76 and 265 HCC patients treated with Sorafenib, respectively. The PNI was calculated as follows: 10 Ă— serum albumin (g/dL) + 0.005 Ă— total lymphocyte count (per mm3). Univariate and multivariate analyses were performed to investigate the association between the covariates and the overall survival (OS). RESULTS:A PNI cut-off value of 31.3 was established using the ROC analysis. In the training cohort, the median OS was 14.8 months (95% CI 12-76.3) and 6.8 months (95% CI 2.7-24.6) for patients with a high (>31.3) and low ( 70 years (p31.3 was found to be an independent prognostic factor for predicting OS in all the three validation cohorts. CONCLUSIONS:PNI represents a prognostic tool in advanced HCC treated with first-line Sorafenib. It is readily available and low-cost, and it could be implemented in clinical practice in patients with HCC