Super hygroscopic non-stoichiometric cerium oxide particles as electrode component for PEM fuel cells

The design of highly efficient promoters for the oxygen reduction reaction (ORR) is an important challenge in the large-scale distribution of proton exchange membrane (PEM) fuel cells. Hygroscopic cerium oxide (CeO2) is here proposed as co-catalyst in combination with Pt. Physical chemical characterizations, by means of X-ray diffraction, vibrational spectroscopy, morphological and thermal analyses, were carried out, demonstrating high water affinity of the synthesized CeO2 nanoparticles. Composite catalysts (i. e., Pt : CeO2 1 : 0.5 and 1 : 1 wt:wt), were studied by either rotating disk electrode (RDE) and fuel cell tests performed at 80 °C and 110 °C. Interestingly, the cell adopting the Pt : CeO2 1 : 0.5 catalyst enabled the achievement of high power densities reaching ∼80 and ∼35 mW cm−2 under low relative humidity and high temperatures. This result demonstrates that tuning material surface properties (e. g. oxygen vacancies) could significantly boost the electrochemical performance of cathodes as a combined result of optimized water retention and improved ORR kinetic

Deciphering the Interplay between Binders and Electrolytes on the Performance of Li4Ti5O12 Electrodes for Li-Ion Batteries

Lithium titanium oxide (Li4Ti5O12, LTO) is an attractive negative electrode for the development of safe-next-generation-lithium-ion batteries (LIBs). LTO can find specific applications complementary to existing alternatives for LIBs thanks to its good rate capability at high C-rates, fast lithium intercalation, and high cycling stability. Furthermore, LIBs featuring LTO electrodes are inherently safer owing to the LTO's operating potential of 1.55 V vs. Li+/Li where the commonly used organic-based electrolytes are thermodynamically stable. Herein, we report the combined use of water-soluble sodium alginate (SA) binder and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-tetraglyme (1m-T) electrolyte and we demonstrate the improvement of the electrochemical performance of LTO-based electrodes with respect to those operating in conventional electrolyte 1M LiPF6-ethylene carbonate: dimethyl carbonate (LP30). We also tackle the analysis of the impact of combining the binder/electrolyte on the long-term cycling performance of LTO electrodes featuring SA or conventional polyvinylidene fluoride (PVdF) as binders. Therefore, to assess the impact of the combination of binder/electrolyte on performance, we performed post-mortem characterization by ex situ synchrotron diffraction experiments of LTO electrodes after cycling in LP30 and 1m-T electrolytes

An electrochemical compatibility investigation of RTIL-based electrolytes with Si-based anodes for advanced Li-ion batteries

Silicon is amongst the most attractive anode materials for Li-ion batteries because of its high gravimetric and volumetric capacity; importantly, it is also abundant and cheap, thus sustainable. For a widespread practical deployment of Si-based electrodes, research efforts must focus on significant breakthroughs to addressing the major challenges related to their poor cycling stability. In this work, we focus on the electrolyte-electrode relationships to support the scientific community with a systematic overview of Si-based cell design strategies reporting a thorough electrochemical study of different room temperature ionic liquid (RTIL)-based electrolytes, which contain either lithium bis(fluorosulfonyl)imide (LiFSI) or lithium bis(trifluoromethylsulfonyl)imide (LiTFSI). Their galvanostatic cycling performance with mixed silicon/graphite/few-layer graphene electrodes are evaluated, with first cycle coulombic efficiency approaching 90% and areal capacity ≈2 mAh/cm2 in the limited cut-off range of 0.1–2 V vs. Li+/Li0. The investigation evidences the superior characteristics of the FSI-based RTILs with respect to the TFSI-based one, which is mostly associated with the superior SEI forming ability of FSI-based systems, even without the use of specific additives. In particular, the LiFSI-EMIFSI electrolyte composition shows the best performance in both Li-half cells and Li-ion cells in which the Si-based electrodes are coupled with 4V-class composite NMC-based cathodes

Immune activation, immune senescence and levels of Epstein Barr Virus in kidney transplant patients: Impact of mTOR inhibitors

Post-transplant lymphoproliferative disorders (PTLD) represent a severe complication in transplanted patients and Epstein-Barr Virus (EBV) is the main driver. Besides immunodepression, immune activation/chronic inflammation play an important role in both virus reactivation and expansion of EBV-positive B cells. The aim of this study was to assess the impact of immunosuppressive strategies on factors involved in the PTLD's pathogenesis. 124 kidney transplanted patients were enrolled in this study: 71 were treated with mycophenolic acid (MPA) and 53 treated with mTOR inhibitor (mTORi), both in combination with different doses of calcineurin inhibitor. At the time of the transplant (T0), profile of inflammation/immune activation and immune senescence didn't differ between the two groups, but after one year of treatment (T1) markers were significantly higher in MPA-treated patients; their immunosenescence process was supported by the greater erosion of telomeres despite their younger age. Percentages of activated B cells and levels of EBV-DNA significantly increased in MPA-treated patients, and at T1 were significantly higher in MPA- than in mTORi-treated patients. Overall, these findings indicate that mTOR inhibitors constrain the inflammation/immune activation and senescence status, thus reducing the expansion of EBV-infected B cells and the risk of virus-associated PTLD in kidney transplant recipients. \ua9 2019 The Author

EVALUATION OF THE INFLUENCE OF PIG HAM POST – SLAUGHTERING REFRIGERATION ON HYGIENIC PARAMETERS SET IN REGULATION EC 2073/2005

In order to evaluate the influence of refrigeration on hygienic parameters, issued by EC Regulation n. 2073:2005 (amended by EC Regulation n. 1441:2007) for swine carcasses, 15 pig hams were tested for microbiological analysis, i.e. enumeration of microorganisms at 30°C and enumeration of enterobacteriacee. Ham swabbing was carried out at the end of slaughtering and after 24 hours of storing in refrigeration cells. The temperature-monitoring recorders were put in the hams at the end of cutting operations of carcasses, when the hams were placed in the refrigeration cells. The drop in the inner temperature of hams was monitored during the 24-hour storing time. In most cases, hams with an increase of background flora after 24 hours, had lower temperature at the beginning of refrigeration and the inner temperature need a shorter time to drop below 20°C, 10°C and 4°C, rather than hams associated with bacterial reduction. Therefore there was no correlation between dropping of temperature and bacterial load of hams, because the hygienic conditions of cutting operations prior to refrigeration have a greater influence on hygienic parameters than refrigeration alone

I progetti gestiti dai Coordinatori: analisi del loro profilo e successo

Obiettivo. Descrivere la storia dei progetti affidati/ gestiti dai Coordinatori infermieristici ospedalieri. Metodi. \uc8 stato incluso un campione di 56 Coordinatori in ruolo da almeno un anno nei reparti di 13 Ospedali del nord Italia, contattati con criterio di convenienza. Tramite un\u2019intervista strutturata sono stati raccolti dati sui progetti gestiti nel 2009, tipologia, origine (bottom up; top down), il numero di operatori coinvolti e stato del progetto al momento dell\u2019intervista (concluso, incompleto, abbandonato). Risultati. Nel 2009 i Coordinatori hanno gestito 114 progetti, in media 1.8/ciascuno (\ub11.2): 94 (82.5%) erano progetti di miglioramento, 17 (14.9%) di accreditamento, e 3 (2.6%) di ricerca. I progetti avevano coinvolto complessivamente 2.732 persone (73.7% dei team) con un impegno medio di 84 ore ciascuno; 55 (48.2%) progetti erano ancora in corso, 52 (45.6%) conclusi, 5 (4.4%) incompleti (ovvero mancavano di valutazione) mentre 2 (1.8%) erano stati abbandonati. Conclusioni. Gli infermieri sono coinvolti in numerosi progetti nelle aziende sanitarie. La fase pi\uf9 trascurata \ue8 il monitoraggio dei risultati e il loro consolidamento: i progetti assorbono molte risorse e per questo \ue8 fondamentale che siano correttamente gestiti e partano da reali problemi ed esigenze dei pazienti

Thermodynamic model of hardness: Particular case of boron-rich solids

A number of successful theoretical models of hardness have been developed recently. A thermodynamic model of hardness, which supposes the intrinsic character of correlation between hardness and thermodynamic properties of solids, allows one to predict hardness of known or even hypothetical solids from the data on Gibbs energy of atomization of the elements, which implicitly determine the energy density per chemical bonding. The only structural data needed is the coordination number of the atoms in a lattice. Using this approach, the hardness of known and hypothetical polymorphs of pure boron and a number of boron-rich solids has been calculated. The thermodynamic interpretation of the bonding energy allows one to predict the hardness as a function of thermodynamic parameters. In particular, the excellent agreement between experimental and calculated values has been observed not only for the room- temperature values of the Vickers hardness of stoichiometric compounds, but also for its temperature and concentration dependencies