218 research outputs found
Effect of the combination of basic fibroblast growth factor and cysteine on corneal epithelial healing after photorefractive keratectomy in patients affected by myopia
No full textBackground: This study sought to evaluate the effect of basic fibroblast growth factor eye drops and cysteine oral supplements on corneal healing in patients treated with photorefractive keratectomy (PRK). Materials and Methods: One hundred and twenty patients treated bilaterally with PRK for myopia were enrolled at one of two eye centers (Clinica Santa Lucia, Bologna, Italy and Department of Ophthalmology, University of Magna Graecia, Catanzaro, Italy) and were treated at the former center. Sixty patients included in the study group (Group 1) were treated postoperatively with topical basic fibroblast growth factor plus oral L-cysteine supplements, whereas 60 subjects included in the control group (Group 2) received basic fibroblast growth factor eye drops. We recorded the rate of corneal re-epithelialization and patients were followed-up every 30 days for 6 months. Statistical analyses were performed on the collected data. Results: The eyes in Group 1 demonstrated complete re-epithelialization at Day 5, whereas the eyes in Group 2 achieved this status on Day 6. No side-effects were reported. Conclusions : Patients treated with basic fibroblast growth factor eye drops and L-cysteine oral supplements benefit from more rapid corneal re-epithelialization. In human eyes, this combination treatment appeared to be safe and effective in accelerating corneal surfacing after surgery. Financial Disclosure: No author has any financial or proprietary interest in any material or method used in this study. Trial Registration: Current Controlled Trials ISRCTN73824458. © 2005 - Indian Journal of Ophthalmology
Contaminant Transfer Between Soil-Atmosphere Interface. Atmosphere Quality in a Low Polluted Area of North-East Italy
No full textHeavy metal and PAH soil pollution delivered by atmospheric depositions were monitored for 12 months within an industrial area located between the towns of Possagno and Castelcucco (both close to Treviso City, northern Italy). We did not distinguished between dry and wet atmospheric depositions and collected them altogether, so that all samples contained both. After sample filtration, residues left on the filter were made of particulate and dissolved by acidic attack while the filtrates were aqueous phases. Both fractions were analyzed separately, but metals were analyzed in the aqueous phase only. Results were compared with literature data on compost. Atmospheric deposition contribution to the overall soil pollution resulted to be negligible with respect to that of compost normally administered as a "safe" fertilizer. Large data variability occurring when dealing with either atmospheric kinds of depositions (which mainly depends on meteoric conditions and emission typology) did not impair such conclusion. Amongst PAH, fluoranthene confirms to be the most abundant in either fractions, almost always followed by phenanthrene and anthracene. PAH detected in the particulate fractions were not originated by house heating but by road traffic. Among metals, Zn2+ dominates in the Possagno industrial area, while Pb presence was low and might have come from road traffic. Overall dustfall contamination was low, even if PAH presence can be underestimated when the road traffic contribution is not taken into account. No correlation seems to exist between industrial activity and the large majority of the air quality parameters monitored by us. Copyright © EM International
Diagnostic imaging and therapy in a case of myasthenia gravis associated with thymic hyperplasia
No full textThe diagnostic approach to a patient with myasthenia gravis to verify the presence of thymic hyperplasia/thymoma is presented. The study of the mediastinal region was necessary. Mediastinal MRI showed the presence of a mass. The differential diagnosis between a mediastinal and an extramediastinal lesion is possible with MRI for its high contrast resolution, good spatial resolution and multiplanarity that allow the detection, localization, evaluation of the extent and/or infiltration of adjacent tissues/organs based on the analysis of adipose cleavages and typing in the different pulse sequences of pathologic tissue with contrast enhancement. Definitive diagnosis of thymic hyperplasia was established. Therefore surgery should be essentially associated with the severity of the clinical presentation rather than with thymic hyperplasia
DIAGNOSTIC IMAGING INFORMATION SYSTEMS: DREAM. REPORTING MANAGEMENT
No full textFrom the clinical standpoint, the report represents the synthesis of the diagnostic process and it is the central activity of radiology. However, reporting cannot be separated from the entire organizational cycle inside the Diagnostic Imaging Department as well as within the structure as a whole. The effectiveness of the contribution an information system can give to the radiologist is related to the information and functional integration of the various applications operating in the hospital and over the territory. Based on these considerations, the main types of support the information tool can offer, are reported together with the primary objectives which were basic to the development of the reporting module within the DREAM system and the major solutions adopted to facilitate the attainment of these objectives
A fully explicit fluid-structure interaction approach based on PFEM and FEM
No full textThe numerical simulation of fluid-structure interaction (FSI) problems involving free-surfaces is of great interest in many engineering applications. Particle-based methods, like PFEM, are particularly suited for the analysis of free-surface flows and fluid-structure interaction with large displacements of the interface. In the current work, a staggered approach for the solution of the FSI problem is proposed. The fluid domain is discretized with an explicit Particle Finite Element Method (PFEM) while the solid domain with a standard Finite Element Method (FEM). The weakly compressible formulation of fluid flow, originally proposed in for the PFEM, allows for a fully explicit solution scheme. Thanks to the Lagrangian formulation, the free surface is directly defined by the current position of the particles, while the governing equations are imposed like in standard FEM. When the mesh becomes too distorted, a fast remeshing algorithm is used to redefine the connectivities. The structural domain is instead analyzed with a standard commercial explicit FEM (SIMULIA Abaqus\Explicit).
The coupling between the fluid and solid domains is treated with the GC Domain Decomposition approach. On each subdomain the problem is solved independently and then the two solutions are linked at the interface using a Lagrange multiplier technique. The proposed method allows for different time-steps in the two subdomains and for non-conforming meshes at the interfaces between the solid and fluid domains. Moreover, this approach allows for an explicit coupling, without iterations, between the two subdomains.
2D test-cases will be presented to validate the proposed coupling technique. The explicit scheme for both the fluid and solid subdomains, together with the explicit treatment of the coupling, makes this method appealing for applications in a variety of engineering problems with fast dynamics and/or a high degree of non-linearity
Nonsymmetric alpha-diimines in Pd-catalyzed ehtene/polar monomer copolymerization
No full textOne of the major unsolved problems in polymer chemistry is represented by the synthesis of functionalized polyolefines, that are currently produced through radical processes, a technology that suffers from high energy consumption, low cost efficiency and poor control over the macromolecule structure.1 The direct, controlled, homogeneously catalyzed copolymerization of ethylene with polar vinyl monomers represents a sustainable technology to overcome these limits. The main catalytic systems reported in the literature are based on Pd(II) compounds with either -diimines or phosphino-sulfonate ligands.2 Their productivity is thus far low from the values required for an industrial application, and better performing catalysts are strongly needed.
With this aim we are studying Pd(II) complexes with new nonsymmetric -diimines (Ar,Ar'-BIAN) featured by an acenaphthene skeleton and one aryl ring substituted in meta positions with electron-withdrawing groups, while the other ring bears electron-releasing substituents on the ortho positions (Figure up). The related monocationic complexes, [Pd(CH3)(Ar,Ar'-BIAN)(L)][PF6], that include both acetonitrile and dimethyl sulfoxide derivatives, have been applied as precatalysts in the ethylene/methyl acrylate copolymerization under mild conditions of temperature and pressure showing a remarkably different catalytic behaviour depending on the nature of the L ligand (Figure below).3 While the catalyst originated from the acetonitrile precursor was found to be less active than the dmso counterpart and to deactivate within 16 h of reaction, that obtained from the dmso derivative was still active after 48 h achieving a productivity of 350 g P/g Pd. The catalysts with the nonsymmetric Ar,Ar'-BIAN showed a productivity twice as high as that of the catalysts with the corresponding symmetric ligands together with a higher incorporation of the polar monomer into the catalytic product. The latter is a mixture of ethylene oligomers and ethylene/methyl acrylate cooligomers, having the polar monomer at the end of the branches. Detailed investigation on the studied catalytic system will be presented.
1A. Nakamura, S. Ito and K. Nozaki, Chem. Rev., 2009, 109, 5215.
2 a) L.K. Johnson, S. Mecking and M. Brookhart, J. Am. Chem. Soc., 1996, 118, 267; b) E. Drent, R. van Dijk, R. van Ginkel B. van Oort and R.I. Pugh, Chem. Commun., 2002, 744.
3A. Meduri, T. Montini, F. Ragaini, P. Fornasiero, E. Zangrando and B. Milani, ChemCatChem published on the web, DOI: 10.1002/cctc.201200520
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