On the interplay between the slowdown of dynamics and the kinetics of aggregation: The case study of a reactive binary mixture.

Modeling the kinetics of aggregation requires a proper strategy to take into account not only the reactivity of reagents but also the ability they have to diffuse. The lack of direct information about diffusion represents the most serious experimental obstacle to the use of diffusion-corrected mean-field equations, which is usually overcome by using information on the structural relaxation dynamics. A very accurate description of the entire kinetics of aggregation can be made by introducing a single time scale of diffusion, set by the structural relaxation time τ of the system according to ∼τ(ξ), with ξ a fractional exponent. Here, we apply this modeling to the case of a reactive binary mixture made of diglycidyl ether of bisphenol-A and 1,3-phenylenediamine, where the reaction proceeds along an autocatalyic (hydroxyl catalyzed) and a non-catalytic (impurity catalyzed) pathway and find that a very small value of the exponent ξ = 0.27 ± 0.03 is needed to reproduce all the data. Our results help revise some preconceived ideas: contrary to widely held assumptions, we find that (i) the time scale of diffusion neither increases proportionally to the structural relaxation time nor is related to τ by a power law with the same fractional exponent as that relating τ to conductivity; (ii) no direct connection exists between the transition to diffusion-control and the development of a gel network or formation of a glassy phase; and (iii) there is no significant difference in the enthalpy barrier for bond formation in the presence of hydroxyl or other than hydroxyl catalyst groups.

[Pulmonary hydatid disease in childhood: a case report]. / Idatidosi polmonare in età infantile: descrizione di un caso clinico.

Echinococcosis/hydatidosis is a parasitic zoonosis caused in humans by the larval stage of the Echinococcus granulosus cestode. Although notification of infestation is required, there are no reliable data on the prevalence of this parasitosis among humans in Italy. This zoonosis was first reported in ancient times (Hippocrates, fourth century BC) and since then many cases of echinococcosis/hydatidosis have been described. Currently, it is considered one of the main parasitoses affecting animals bred for income and one of the most important parasitic zoonoses. We present the clinical case of a three-year-old child, living in Palermo with a dog in his house, who came to our observation for dyspnea occurring after physical exercise. Diagnosis of echinococcosis was performed on the operating table and by histological examination. The case presented is special in its manifestation from a clinical point of view, because the young patient experienced multiple injuries only to lungs, without involvement of other organs and, although the left lung cysts appeared fissured on the operating table, our patient never presented immunoallergic disorders.

[Hormonal, auxological and clinical follow-up in children with connatal HIV infection: personal records]. / Valutazione plurispecialistica per un follow-up clinico, auxologico ed endocrino di pazienti con infezione connatale da HIV: dati di una casistica personale.

Auxological and endocrinological complications frequently occur in children with connatal HIV infection. These complications seem to be related both to the infection itself and the antiretroviral therapy. Many children consequently show height-weight and pubertal retardation without any evidence of hormonal deficit. We studied 10 children with connatal HIV infection who were enrolled in this analysis and followed up for 7 years in order to evaluate their height-weight growth, pubertal maturation, bone age progression and hormonal pattern [basal Growth hormone (GH) and GH after Clonidine or Insulin stimulation, Insulin-like Growth Factor 1 (IGF-1), Insulin-like Growth Factor Binding Protein 3 (IGFBP-3), FSH, LH, ACTH and Cortisol, TSH, fT4, T4, T3, Ab-TGO, Leptin]. Three children showed a height lower than 3rd centile during the first two years of their life and in prepubertal age, with recurring improvement in their growth rate. Weight growth was very compromised in one girl, remaining firmly lower than 3rd centile during the follow-up. Three children presented a weight lower than 3rd centile until they were two years old. However, a height growth rate higher than 10th centile was found in nine children throughout the follow-up, while it was pathological in five children. The blood level of Leptin was higher at the beginning of the study: 0.82 - 11.68 ng/l (M+/-DS: 3.29+/-4.15) than at its conclusion: 0.2 - 3 ng/l (M+/-DS: 1.65+/-1.01). There was a statistically significant correlation between leptinemia and the CD4/CD8 count (p: 0.010; r: 0.916) and the CDC classification (p: 0.006; r: 0.937), indicating a strong relationship with the degree of virological and immunological impairment. The authors stress the importance of a careful height-weight growth rate control in HIV-infected children, as it reflects the clinical and virological course of the disease. Adequate control of the infection allows physiological growth in most patients. Moreover, we emphasize the utility of IGFBP-3 and IGF-1 measurements, since they represent growth markers which are more exact and better capable of reproduction than GH.