486 research outputs found
Corrigendum to "2nd St. Gallen EORTC Gastrointestinal Cancer Conference: Consensus recommendations on controversial issues in the primary treatment of rectal cancer" [Eur J Cancer 63 (August 2016) 11-24].
No full textThe authors regret that the name of the co-author Salvatore Pucciarelli was misspelt in the original version of this article. The correct spelling is Salvatore Pucciarelli as given here. The authors would like to apologise for any inconvenience caused
Semiconductor properties of the anodic polymer obtained on platinum from selenocyanate ammoniate
No full textOn the mechanism of final heat transfer restoration at the transition to gas-like fluid at supercritical pressure: A description by CFD analyses
No full textIn this paper, while presenting progresses in the prediction of heat transfer to supercritical pressure carbon
dioxide by a CFD model, a particular focus is assigned to an interesting phenomenon highlighted by the considered
experimental database. This phenomenon is observed in several operating conditions when deteriorated
heat transfer starts because of flow laminarisation, as a consequence of buoyancy effects at sufficiently low inlet
temperature, while it is suddenly suppressed when reaching higher enthalpy along the pipe or when the inlet
temperature is increased. The observed behaviour has a clear root in the density differences between the fluid at
the wall and in bulk, which are firstly responsible for the onset of deterioration and then become no more
sufficient to sustain it. While experimental data can only show the deteriorated heat transfer to appear and
disappear, in terms of values of increasing and decreasing temperatures at the wall, a recently upgraded turbulence
model showed an interesting ability to reproduce these wall temperature data, at the same time providing
a clear picture of the conditions justifying the observed behaviour. In this regard, the good predictions of
wall temperature, as the only measurable data, in some of the addressed conditions give confidence that the
model is helpful to explain the reasons for the observed behaviour, shading light on the mechanisms producing
this interesting phenomenon, so clearly shown in the considered experimental data set
Quality of life and functions after chemoradiation for rectal cancer: A review of recent publications
No full textWe have systematically reviewed studies published in the last three years on patients' self-reported evaluations of quality of life (QoL) and functions after chemoradiotherapy (CRT) for rectal cancer. Overall, the findings from 13 studies confirmed that CRT negatively affect functions and, consequently, patients' QoL, especially for bowel, role, and social function. The studies' heterogeneity limited the possibility of comparison among findings. We discuss and comment on the ideal characteristics of studies assessing QoL and function. We emphasise how this type of evidence is relevant to decision-making at all levels of health-care practice. © 2013 Springer Science+Business Media New York
Analysis of thermal stratification phenomena in the CIRCE-HERO facility
No full textIn the present paper, CFD simulations related to the operating conditions considered during the experimental campaign on CIRCE-HERO facility are presented, with the aim of investigating the observed temperature stratification phenomena. Calculations are performed using the commercial codes STAR-CCM+ and ANSYS Fluent adopting a RANS approach; the numerical results and the experimental data are compared. Four distinct experimental tests are investigated also performing sensitivity analyses regarding the boundary conditions. In particular, assumptions concerning the heat losses distribution and the shape of the pool inlet were taken into account. The numerical results provide support for further understanding of the involved phenomena, suggesting the possible causes of the thermal stratification observed experimentally inside the pool. Similar trends for the predicted and experimental data were obtained and – even from a quantitative point of view - the observed discrepancies can be considered acceptable, assuming the uncertainties in the experimental boundary conditions and measurement
Analysis of the temperature distribution in the pin bundle of the CIRCE facility
No full textIn this paper, a CFD analysis of the Fuel Pin Simulator (FPS) of the CIRCE-HERO facility built at the ENEA research centre in Brasimone was performed. STAR-CCM + code was used with the purpose of reproducing steady-state and transient experimental conditions adopting LBE as working fluid. RANS and URANS simulations were performed comparing the calculated temperature trends with the experimental data. In particular, the FPS average outlet temperature was monitored for the transient case and an exhaustive study of the heat transfer between the FPS and the pool during the transient was carried out. The impact of the involved heat transfer phenomena on the FPS energy balance was studied from a quantitative point of view and the relevant difference in terms of thermal inertia between pool and FPS component was pointed out
Photoelectrochemical effect of the anodic deposit obtained on platinum from selenocyanate ammoniate.
No full text
Synthesis and characterization of poly-phosphane coinage metals complexes and study on the protein ligation and catalysis
No full textA series of coinage metals centered poly-phosphane complexes has been synthesized and characterized under photophysical, chemical and biochemical aspects also in combination with a protein. Poly-phosphane metal complexes possess many properties in the field of luminescence,[1] catalysis, [2] chemo sensing, [3] and of anticancer activity [4]. In this study phosphane ligands containing the carboxylic functional group in ortho or para position of PPh3 have been used. The introduction of this polar group has the double aim either to make more hydrophilic the complexes and to tune the binding ability of the phosphane. In the case of gold(I) complexes, the poly-phosphine compound have been studied in comparison with the corresponding [bis-triphenylphosphine-gold(I)chloride], where the carboxylic group is absent, to evaluate the influence of its presence in the photopysical properties as well as on the interaction with dihydrofolate reductase, a protein involved in cell proliferation, DNA duplication and many other biological functions [5]. Affinity constants have been estimated through quenching of fluorescence studies and inhibition constants have been evaluated through rate constant determination of the reduction of dihydrofolate (H2F) to tetrahydrofolate (H4F) with reduced nicotinamide adenide dinucleotide phosphate (NADPH) as hydride donor. The tests highlighted a catalytic activity of the gold(I) compounds versus the H2F, which is the substrate of the enzyme. A strong effect of the enzyme on the luminescence properties of the gold(I) complexes have been observed. A coinage metals homolog series have been also evaluated as antiproliferative agent by in vitro MTT tests.
Scheme. Schematic view of a homolog series of coinage metals complexes under study.
References
1. R. Edward, T. Tiekink, J. G. Kang, Coord. Chem. Rev. 2009, 253, 1627-1648
2. David J. Gorin, Benjamin D. Sherry, and F. Dean Toste, Chem. Rev. 2008, 108, 3351–3378
3. X. He, V. W. Yam, Coord. Chem. Rev. 2011, 2111-2123
4. R. Galassi, A.Burini, O. Camille Simon, A. Dolmella, D. Micozzi, S. Vincenzetti, S. Pucciarelli Dalton Trans., 2015, 44, 3043-3056 DOI: 10.1039/C4DT01542H
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A successful general fluid-to-fluid similarity theory for heat transfer at supercritical pressure
No full textThe present paper introduces a successful and general fluid-to-fluid similarity theory for heat transfer to fluids at supercritical pressure, having a high degree of universality. This work shortly follows the recent publication of a “local” successful similarity theory developed for fluids at supercritical pressures in a range of conditions in which the values of their molecular Prandtl number were quantitatively similar, extending its conclusions to the case of different molecular Prandtl numbers. The reason why this further step requested a short time to be elaborated is due to recognising that previous work by the Authors had actually already solved the related problems, though in a slightly different way, now interpreted in a more significant frame owing to a better problem understanding. The present similarity theory is based on first ideas developed more than one and a half decade ago by one of the authors, while addressing flow stability of supercritical fluids in heated channels, which encountered immediate problems to be applied in a straightforward way to heat transfer. These ideas were revised and considerably improved during the PhD thesis of the other author, also overcoming a sort of prejudicial assumption that finally resulted to limit their applicability. More recently, published DNS data triggered further reflections on the role of the Prandtl number, leading to the mentioned “local” form of the successful similarity theory. This led to the present step, by just recognising that the mentioned PhD thesis had already proposed a sufficient rationale to extend this local interpretation to a broader range of conditions. The rather convincing results presented herein, obtained making use of RANS CFD analyses with four different fluids, demonstrate the interesting capabilities of this final form of the theory. The establishment of an effective set of dimensionless numbers for heat transfer problems is hoped to pave the way for the development of the still lacking successful engineering heat transfer correlations for supercritical pressure fluids. It further calls for dedicated experiments needed to confirm the suitability of the present theory beyond any reasonable doubt
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