University of Perugia

About: University of Perugia is a education organization based out in Perugia, Umbria, Italy. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 13365 authors who have published 39516 publications receiving 1265601 citations. The organization is also known as: Universitá degli Studi di Perugia & Universita degli Studi di Perugia.

Influence of the dye molecular structure on the TiO2 conduction band in dye-sensitized solar cells: disentangling charge transfer and electrostatic effects†

Abstract: We report a thorough theoretical and computational investigation of the effect of dye adsorption on the TiO2 conduction band energy in dye-sensitized solar cells that is aimed at assessing the origin of the shifts induced by surface adsorbed species in the position of the TiO2 conduction band. We thus investigate a series of working dye sensitizers and prototypical surface adsorbers and apply an innovative approach to disentangle electrostatic and charge-transfer effects occurring at the crucial dye–TiO2 interface. We clearly demonstrate that an extensive charge rearrangement accompanies the dye–TiO2 interaction, which amounts to transfer of up to 0.3–0.4 electrons from the dyes bound in a dissociative mode to the semiconductor. Molecular monodentate adsorption leads to a much smaller CT. We also find that the amount of CT is modulated by the dye donor groups, with the coumarin dyes showing a stronger CT. A subtle modulation of the semiconductor conduction band edge energy is found by varying the nature of the dye, in line with the experimental data from the literature obtained by capacitance and open circuit voltage measurements. We then decompose the total conduction band shift into contributions directly related to the sensitizer properties, considering the effect of the electric field generated by the dye on the semiconductor conduction band. This effect, which amounts to ca. 40% of the total shift, shows a linear correlation with the TiO2 conduction band shifts. A direct correlation between the dye dipole and the observed conduction band shift is retrieved only for dyes of similar structure and dimensions. We finally found a near-exact proportionality between the amount of charge transfer and the residual contribution to the conduction band shift, which may be as large as 60% of the total shift. The present findings constitute the basis for obtaining a deeper understanding of the crucial interactions taking place at the dye–semiconductor interface, and establish new design rules for dyes with improved DSC functionality.

B7/CD28-Dependent CD4 + CD25 + Regulatory T Cells Are Essential Components of the Memory-Protective Immunity to Candida albicans

Abstract: Protective immunity to the fungus Candida albicans is mediated by Ag-specific Th1 cells. Paradoxically, some Th2 cytokines are required for the maintenance of Th1-mediated immune resistance to the fungus. Therefore, in addition to the Th1/Th2 balance, other mechanisms seem to be involved in the regulation of Th1 immunity to the fungus. Here we show that CD4(+)CD25(+) T cells, negatively regulating antifungal Th1 reactivity, are generated in mice with candidiasis. CD4(+)CD25(+) T cells were not generated in B7-2- or CD28-deficient mice or in condition of IL-10 signaling deficiency. Accordingly, although capable of efficiently restricting the fungal growth, these mice experienced inflammatory pathology and were incapable of resistance to reinfection. CD4(+)CD25(+) T cells poorly proliferated in vitro; were highly enriched for cells producing IL-4, IL-10, and TGF-beta; and required IL-10-producing, Candida hypha-activated dendritic cells for generation. Adoptive transfer of CD4(+)CD25(+) T cells or IL-10-producing dendritic cells restored resistance to reinfection and decreased inflammation in B7-2-deficient mice. These results show that oral tolerance induced by Candida hyphae is required for the occurrence of long-lasting protective immunity after yeast priming. The implication is that preventing reactivation rather than favoring sterilizing immunity to ubiquitous fungal pathogens may represent the ultimate expectation of vaccine-based strategies.

Evidence for Collective Multiparticle Correlations in p-Pb Collisions

Abstract: The second-order azimuthal anisotropy Fourier harmonics, v2, are obtained in pPb and PbPb collisions over a wide pseudorapidity (eta) range based on correlations among six or more charged particles. The pPb data, corresponding to an integrated luminosity of 35 inverse nanobarns, were collected during the 2013 LHC pPb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. A sample of semi-peripheral PbPb collision data at sqrt(s[NN])= 2.76 TeV, corresponding to an integrated luminosity of 2.5 inverse microbarns and covering a similar range of particle multiplicities as the pPb data, is also analyzed for comparison. The six- and eight-particle cumulant and the Lee-Yang zeros methods are used to extract the v2 coefficients, extending previous studies of two- and four-particle correlations. For both the pPb and PbPb systems, the v2 values obtained with correlations among more than four particles are consistent with previously published four-particle results. These data support the interpretation of a collective origin for the previously observed long-range (large Delta[eta]) correlations in both systems. The ratios of v2 values corresponding to correlations including different numbers of particles are compared to theoretical predictions that assume a hydrodynamic behavior of a pPb system dominated by fluctuations in the positions of participant nucleons. These results provide new insights into the multi-particle dynamics of collision systems with a very small overlapping region.

Itraconazole Oral Solution as Prophylaxis for Fungal Infections in Neutropenic Patients with Hematologic Malignancies: A Randomized, Placebo-Controlled, Double-Blind, Multicenter Trial

Abstract: To evaluate the efficacy and safety of itraconazole oral solution for preventing fungal infections, a randomized, placebo-controlled, double-blind, multicenter trial was conducted: 405 neutropenic patients with hematologic malignancies were randomly assigned to receive either itraconazole, 2.5 mg/kg every 12 hours (201 patients), or placebo (204 patients). Proven and suspected deep fungal infection occurred in 24% of itraconazole recipients and in 33% of placebo recipients, a difference of 9 percentage points (95% confidence interval [CI], 0.6% to 22.5%; P = .035). Fungemia due to Candida species was documented in 0.5% of itraconazole recipients and in 4% of placebo recipients, a difference of 3.5 percentage points (95% CI, 0.5% to 6%; P = .01). Deaths due to candidemia occurred in none of the itraconazole recipients compared with 4 placebo recipients, a difference of 2 percentage points (95% CI, 0.05% to 4%; P = .06). Aspergillus infection was documented in four itraconazole recipients (one death) and one placebo recipient (one death). Side effects causing drug interruption occurred in 18% of itraconazole recipients and 13% of placebo recipients. Itraconazole oral solution was well-tolerated and effectively prevented proven and suspected deep fungal infection as well as systemic infection and death due to Candida species.

Accuracy of four intraoral scanners in oral implantology: a comparative in vitro study.

Abstract: Background Until now, only a few studies have compared the ability of different intraoral scanners (IOS) to capture high-quality impressions in patients with dental implants Hence, the aim of this study was to compare the trueness and precision of four IOS in a partially edentulous model (PEM) with three implants and in a fully edentulous model (FEM) with six implants Methods Two gypsum models were prepared with respectively three and six implant analogues, and polyether-ether-ketone cylinders screwed on These models were scanned with a reference scanner (ScanRider®), and with four IOS (CS3600®, Trios3®, Omnicam®, TrueDefinition®); five scans were taken for each model, using each IOS All IOS datasets were loaded into reverse-engineering software, where they were superimposed on the reference model, to evaluate trueness, and superimposed on each other within groups, to determine precision A detailed statistical analysis was carried out Results In the PEM, CS3600® had the best trueness (458 ± 16μm), followed by Trios3® (502 ± 25μm), Omnicam® (588 ± 16μm) and TrueDefinition® (614 ± 30μm) Significant differences were found between CS3600® and Trios3®, CS3600® and Omnicam®, CS3600® and TrueDefinition®, Trios3® and Omnicam®, Trios3® and TrueDefinition® In the FEM, CS3600® had the best trueness (606 ± 117μm), followed by Omnicam® (664 ± 39μm), Trios3® (672 ± 69μm) and TrueDefinition® (1064 ± 231μm) Significant differences were found between CS3600® and TrueDefinition®, Trios3® and TrueDefinition®, Omnicam® and TrueDefinition® For all scanners, the trueness values obtained in the PEM were significantly better than those obtained in the FEM In the PEM, TrueDefinition® had the best precision (195 ± 31μm), followed by Trios3® (245 ± 37μm), CS3600® (248 ± 46μm) and Omnicam® (263 ± 15μm); no statistically significant differences were found among different IOS In the FEM, Trios3® had the best precision (315 ± 98μm), followed by Omnicam® (572 ± 91μm), CS3600® (655 ± 167μm) and TrueDefinition® (753 ± 438μm); no statistically significant differences were found among different IOS For CS3600®, For CS3600®, Omnicam® and TrueDefinition®, the values obtained in the PEM were significantly better than those obtained in the FEM; no significant differences were found for Trios3® Conclusions Significant differences in trueness were found among different IOS; for each scanner, the trueness was higher in the PEM than in the FEM Conversely, the IOS did not significantly differ in precision; for CS3600®, Omnicam® and TrueDefinition®, the precision was higher in the PEM than in the FEM These findings may have important clinical implications