450 research outputs found
Le variabili sociodemografiche: generazione, genere, istruzione e famiglia
No full textIl cambiamento nelle scelte elettorali degli italiani fra il 1968 e il 2008 viene analizzato alla luce delle influenze su esso esercitate da: generazione, genere, istruzione e orientamento politico della famiglia di origin
Response to the Letter to the Editor on “The arthroereisis procedure in adult flexible flatfoot grade IIA due to insufficiency of posterior tibial tendon”
No full textPreliminary tests to select operating conditions for the accurate determination of stability constant by cation exchange chromatography: the Cd2+-Cl- and Cd2+-NO3- systems
No full textIon chromatography (IC) has been demonstrated to be a powerful tool for equilibrium constant determination, related to various cation-ligand systems. Nevertheless, no systematic research has been carried out to develop preliminary checks in order to verify whether the variation in ligand concentration in the eluent at constant ionic strength affects the exchange mechanism for the system of interest in the selected chromatographic column. In this paper, tests are proposed which allow one to determine beforehand the experimental conditions to be used in cation-exchange chromatography, whereby parallel mechanisms of elution (mainly in the reversed-phase mode) are avoided. In this way IC becomes an independent rather than an auxiliary means to obtain accurate βi values. Cd(II)Cl- and Cd(II)NO3 - systems were considered and are discussed
The arthroereisis procedure in adult flexible flatfoot grade IIA due to insufficiency of posterior tibial tendon
No full textBackground: To report on the functional, biomechanical, and radiographic results of patients who had undergone arthroereisis plus tensioning of the posterior tibial tendon for flexible flatfoot. The hypothesis is that arthroereisis associated to a tensioning of the posterior tibial tendon give a good correction with great satisfaction in patients with flexible flatfoot in grade IIA. Methods: We evaluated 29 patients (31 feet), mean age of 46.4 years, who had been surgically treated for adult flatfoot grade IIA according to Myerson. Mean follow-up was 34.15 months. For clinical evaluation, the AOFAS hindfoot and VAS-FA scores were used. Results: Postoperative results showed significant increases in both AOFAS and VAS-FA scores: 54.2–81.9 and 61.5–83.2 points, respectively. For the X-ray parameters, we observed a significant variation in the talo-first metatarsal angle, from 13.8° in pre-op to 7.4° in post-op. In lateral view, Djian Annonier angle was improved from 146.6° to 134.1°. The Meary's angle, compared to an average of 8.8° in pre-operative stage improved to 4.3° in the post-operative stage. Postoperative satisfaction was excellent-good according to 23 patients (79.4%). Pain in the tarsal sinus was reported in 5 out of 31 feet (16.1%) for the first three months after surgery. Conclusions: Arthroereisis and tensioning of the posterior tibial tendon provided good functional outcomes for patients under 60 years of age having stage IIA flexible flatfoot without arthritic manifestations
BOOK REVIEW: Il partito di Grillo, Corbetta, P. e Gualmini, E., (a cura di), Bologna, il Mulino, 2013
No full textEnhancing the quality of information obtained by a comparison between experimental and deconvolved peak parameters in ion chromatography
No full textChromatographic peaks are generally asymmetric owing to extra- and intra-column effects. This implies that the experimental retention time, t(R,p), and variance, σ 2/(p), do not properly describe the shape of a peak under the experimental conditions used, nor do they allow one to predict how this shape will change when the composition of the eluent is varied. Consequently, some of the conclusions drawn from these experimental parameters may contain an extent of error that cannot be evaluated. This may occur for instance when some of the lower order statistical moments are used to estimate thermodynamic properties related to the solute-eluent- chromatographic column system. The aim of this paper is to test whether and to what extent information can be improved in ion chromatography when the moments estimated by some suitable fitting functions are compared to the experimental ones. The following fitting functions were tested: the exponentially modified Gaussian (EMG) (the peak deconvolution leads to the Gaussian curve which would be obtained in the absence of distortion), the bi- Gaussian (bi-G) (the deconvolution leads to the sum of two half-Gaussians), and the two-Gaussians (2-G) (the deconvolution leads to two Gaussians). The last one is proposed in this paper for the first time. Once we had evaluated how each component of a modern IC chromatograph (namely loop, column, post- column conditioning module and detector) affects the peak shape, the three fitting models were tested: (i) to compute β 1, and β 2 stability constants for the Cd +2/Cl - system from the measurement of the first-order moments at a variable Cl - concentration and constant ionic strength (0.22). It was found that: β 1 =28.86 (EMG), 28.53 and 28.59 (2-G), 28.99 (bi-G) and β 2 = 57.96 (EMG), 59.01 and 58.98 (2-G), 53.92 (bi-G). The β values calculated from the experimental retention times referred to the peak maximum were: β 1 =27.89 and β 2 =64.95; (ii) to evaluate, for the various solutes, the dependence on the first order moment (m 1) of some parameters of the i fitting functions, such as τ (the time constant of the exponential modifier in the EMG), σ(i) (the square root of peak variance) and the asymmetry a/b (graphically measured as the ratio of the distances of the peak contour from the abscissa of peak maximum, at 0.1 peak height). A linear dependence on m 1 was found for: σ(i) with a slope which depends on the fitting model used and not on the type of solute: τ and a/b with a slope which depends on the solute type. These findings are of interest: (i) to provide a sound tool for the accurate IC estimate of stability constants based on the Gaussian first order moment computed from the deconvolution of the experimentally distorted peak (ii) to evaluate how the shape of the solute peak changes with m 1 when the shift of the peak along the time (or volume) scale due to variations in the eluent composition can be thermodynamically predicted. In the last case the optimized peak separation conditions, which take the effect of peak shape variation into account, might be more efficiently found
- …
