Dynamical Dark Energy and Spontaneously Generated Gravity

We study the cosmological evolution of an induced gravity model with a scale symmetry breaking potential for the scalar field. The radiation to matter transition, following inflation and reheating, influences the dynamics of such a field through its non minimal coupling. We illustrate how, under certain conditions on the potential, such a dynamics can lead to a suitable amount of dark energy explaining the present accelerated expansion.Comment: 14 pages, 3 figure

The impact of light and heavy hydrocarbons on the NH3-SCR activity of commercial Cu- and Fe-zeolite catalysts

Low temperature operation of NH3-SCR systems for NOx abatement in lean burn and Diesel engines poses new demanding challenges due to the necessity of solving issues related to poor catalyst activity, urea injection management and system control. A typical example of these problems is represented by unconverted hydrocarbons (HCs) slip (e.g. during cold start or long idling) onto the SCR catalyst leading to a subsequent decrease of the DeNOx activity. In the present work, a detailed evaluation of the impact of different hydrocarbons (namelyC3H6and C10H22) on the performances of two new generation commercial zeolite SCR catalysts promoted with Fe and Cu is carried out by means of transient response method (TRM) experiments. Particular attention is devoted to elucidate the interaction between HCs and the typical constituents of SCR feed such as NH3, NO, NO2, O2and H2O and their influence on the overall reactivity, in order to possibly clarify the associated mechanistic steps

Dietary supplementation of chestnut and quebracho tannins mix: Effect on caecal microbial communities and live performance of growing rabbits

The interest in antimicrobial compounds as feed additives is currently increasing. Among different options, tannins seem to have several beneficial effects when employed in animals diet. The present study aimed at investigating the influence on caecal microbial communities of the supplementation of a chestnut and quebracho tannins mix in meat rabbit's diet, also considering animals live performances. Four groups of rabbits were fed with a different diet: a control diet (C); a control diet with coccidiostat (CC), and two experimental diets with 0.3% (T0.3) and 0.6% (T0.6) chestnut and quebracho tannins mix. For microbial analysis, culture-dependent and culture-independent methods were employed. Live performances were not significantly affected by tannins mix supplementations, as well as culturable microbial loads of E. coli, Enterobacteriaceae, Bacteroides spp. and Bifidobacterium spp. C. perfringens was always under the detection limit. A consistent result was obtained by qPCR. As for PCR-DGGE analysis, the Richness and evenness (Shannon-Weiner index) of bacterial communities in caecum resulted significantly higher in control samples (C and CC) than in those from rabbit fed with tannin-containing diets. Sequencing analysis revealed that the phylum Firmicutes was less represented in samples from control groups. As for the methanogen archaeal DGGE, no significant differences were found in richness and diversity among different groups, all dominated by Methanobrevibacter spp.. This work highlights the potential antimicrobial effect of chestnut and quebracho tannins mix in an in vivo system revealed by molecular analysis

Discontinuation of anti-PD1 in advanced melanoma: an observational retrospective study from the Italian Melanoma Intergroup

Background: Immunotherapy has improved the survival of patients with stage IV melanoma. In responders, clinical benefits may be long-lasting and persist even after treatment discontinuation. The optimal duration of anti-PD1 (anti-Programmed cell death-1) therapy in metastatic melanoma patients remains to be elucidated. Moreover, limited data are available on clinical outcomes of patients that discontinued anti-PD1 immunotherapy in a real-life setting. The aim of this study was to evaluate the progression-free survival (PFS) in patients with metastatic melanoma who interrupted anti-PD-1 treatment in the in the absence of disease progression. Methods: We retrospectively reviewed patients with advanced/metastatic melanoma treated with anti-PD1 immunotherapy at 23 Italian Melanoma Intergroup (IMI) centres. The study investigated the risk of relapse in patients who stopped anti-PD1 therapy due to CR (Complete response), treatment-related toxicity, or by their own choice after a long period of treatment. Clinical and biological factors associated with or without recurrence were evaluated. Results: The study population included 237 patients. The median age of patients was 68.9 years (standard deviation: 13; range 33-95). The median time on treatment was 33 months (standard deviation: 18, 7; range 1-98). Among the 237 patients, 128 (54%) interrupted the anti-PD1 for CR, 74 patients (31.2%) for adverse events (37 patients in CR, 27 patients in partial response (PR), ten patients in stable disease (SD), and 35 patients (14.8%) by their own choice (12 patients in CR, 17 patients in PR, and 6 patients in SD). After a mean follow-up of 21 months (range 1-81), PFS after anti-PD1 discontinuation was 85.7%. Thirty-four patients (14.3%) developed disease progression after a median of 12 months (range 1-35): ten patients (29.4%) after discontinuation in CR, 17 patients (50%) after discontinuation for treatment-related toxicity (seven in CR, five in PR, five in SD), and seven (20.6%) after discontinuation due to the patient's decision (two in CR, four in PR, one in SD). Only 7.8% of patients who interrupted in CR (10/128), along with 23% of patients who interrupted for limiting toxicity (17/74) and 20% of patients who interrupted by their own choice (7/35), developed recurrence. Regarding patients who discontinued therapy because of CR, we observed a negative association between recurrence and site of primary melanoma, especially mucosal sites (p = <0.05, HR (Hazard ratio) 15.57 IC (confidence interval) 95% 2.64-91.73). Moreover, M1b patients who achieved a CR showed a lower number of relapses (p = <0.05, HR 3.84 IC 95% 1.40-8.48). Conclusions: This study shows in a real-life setting that, with anti-PD-1 therapy, long-lasting responses, can be maintained after anti-PD1 interruption. In 70.6% of cases, recurrences were observed among patients who did not obtain a CR at treatment discontinuation

Management of patients with atopic dermatitis undergoing systemic therapy during COVID‐19 pandemic in Italy: Data from the DA‐COVID‐19 registry

Background Few and small studies have described the management of immunomodulant/immunosuppressive therapies or phototherapy in atopic dermatitis (AD) patients during coronavirus disease 2019 (COVID-19) pandemic.Methods A national registry, named DA-COVID-19 and involving 35 Italian dermatology units, was established in order to evaluate the impact of COVID-19 pandemic on the management of adult AD patients treated with systemic immunomodulant/immunosuppressive medications or phototherapy. Demographic and clinical data were obtained at different timepoints by teledermatology during COVID-19 pandemic, when regular visits were not allowed due to sanitary restrictions. Disease severity was assessed by both physician- and patient-reported assessment scores evaluating itch intensity, sleep disturbances, and AD severity.Results A total of 1831 patients were included, with 1580/1831 (86.3%) continuing therapy during pandemic. Most patients were treated with dupilumab (86.1%, 1576/1831) that was interrupted in only 9.9% (156/1576) of cases, while systemic immunosuppressive compounds were more frequently withdrawn. Treatment interruption was due to decision of the patient, general practitioner, or dermatologist in 39.9% (114/286), 5.6% (16/286), and 30.1% (86/286) of cases, respectively. Fear of increased susceptibility to SARS-CoV-2 infection (24.8%, 71/286) was one of the main causes of interruption. Sixteen patients (0.9%) resulted positive to SARS-CoV-2 infection; 3 of them (0.2%) were hospitalized but no cases of COVID-related death occurred.Conclusions Most AD patients continued systemic treatments during COVID pandemic and lockdown period, without high impact on disease control, particularly dupilumab-treated patients

Management of patients with atopic dermatitis undergoing systemic therapy during COVID-19 pandemic in Italy: data from the DA-COVID-19 registry

Background: Few and small studies have described the management of immunomodulant/immunosuppressive therapies or phototherapy in atopic dermatitis (AD) patients during coronavirus disease 2019 (COVID-19) pandemic. Methods: A national registry, named DA-COVID-19 and involving 35 Italian dermatology units, was established in order to evaluate the impact of COVID-19 pandemic on the management of adult AD patients treated with systemic immunomodulant/immunosuppressive medications or phototherapy. Demographic and clinical data were obtained at different timepoints by teledermatology during COVID-19 pandemic, when regular visits were not allowed due to sanitary restrictions. Disease severity was assessed by both physician- and patient-reported assessment scores evaluating itch intensity, sleep disturbances, and AD severity. Results: A total of 1831 patients were included, with 1580/1831 (86.3%) continuing therapy during pandemic. Most patients were treated with dupilumab (86.1%, 1576/1831) that was interrupted in only 9.9% (156/1576) of cases, while systemic immunosuppressive compounds were more frequently withdrawn. Treatment interruption was due to decision of the patient, general practitioner, or dermatologist in 39.9% (114/286), 5.6% (16/286), and 30.1% (86/286) of cases, respectively. Fear of increased susceptibility to SARS-CoV-2 infection (24.8%, 71/286) was one of the main causes of interruption. Sixteen patients (0.9%) resulted positive to SARS-CoV-2 infection; 3 of them (0.2%) were hospitalized but no cases of COVID-related death occurred. Conclusions: Most AD patients continued systemic treatments during COVID pandemic and lockdown period, without high impact on disease control, particularly dupilumab-treated patients