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A series of biodegradable porous sponges was prepared by using a combination of collagen and poly(∊-caprolactone) in various compositions. To improve the control on the characteristics of the products, hybrid crosslinking methods were applied. Short-range and long-range crosslinking techniques based on physical and chemical crosslinking approaches were combined, including UV irradiation, the use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxy-succinimide system, sylanols and of a bifunctional poly(∊-caprolactone) reactive derivative. The new hybrid polymeric materials were characterized by Fourier transform infrared (FTIR) spectroscopy and thermal analysis (DSC). The morphology and swelling behavior of the products were also studied. It was found that matrix features depend on the concentration of poly(∊-caprolactone) derivative used as a long-range crosslinker in the initial formulation and on preparation conditions, especially on UV irradiation duration. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxane-α,ω-diol was used as matrix for the preparation of polysiloxane-SiO2-TiO2 composites through in situ incorporation of silica and titania using a solvent-free sol-gel procedure. For this purpose, oxide precursors tetraethyl-orthosilicate and tetrabutyl-orthotitanate, and a proper condensation catalyst, viz. dibuthyltin dilaurate, were added in pre-established amounts to the polymer. The hydrolysis and condensation reactions take place under mild conditions, with the formation of silicon and titanium oxide networks and polymer crosslinking. The effect of SiO2 and TiO2 mass ratio on the morphology of the composites was investigated by scanning electron microscopy (SEM) and X-rays diffraction (XRD), and interpreted in correlation with differential scanning calorimetry (DSC) and energy-dispersive X-ray spectroscopy (EDX) data. The film samples were tested as active elements in actuation devices. [ABSTRACT FROM AUTHOR]

High molecular weight methyl methacrylate (M) - styrene (M) copolymers were obtained by plasma-induced bulk copolymerization. The reactivity ratios, determined by Kelen - Tüdös method, were shown to be r=0.41±0.01 r=0.57±0.01 and the coisotactic alternating addition probability G=0.48±0.02. These data indicate a radical mechanism of copolymerization. [ABSTRACT FROM AUTHOR]

Background. ROHHADNET syndrome is a pleiotropic disorder defined by rapid onset of obesity, hypothalamic-pituitary endocrine dysfunctions, alveolar hypoventilation and hypothalamic autonomic dysregulation and neural tumors. Case presentation. We report the case of a 5.8-year-old female patient with rapid onset of obesity and growth arrest, hypercortisolism, hyperprolactinemia, low IGF1, severe hypernatremia (with no signs of diabetes insipidus) and chronic hyperchloremic metabolic acidosis. Additional symptoms included sleep apnea and two episodes of cardiopulmonary arrest after mild sedation. Brain MRI, chest and abdominal enhanced CT scans were all negative. As no tumors were revealed at the time of diagnosis, ROHHAD syndrome was suspected. Treatment with potassium bicarbonate was initiated in an attempt to control both the severe hypernatremia and chronic hyperchloremic metabolic acidosis. Patient developed dilated cardiomyopathy and kaliopenic nephropathy. Conclusion. The presence of dilated cardiomyopathy is in keeping with only one other reported case, while the severe hypernatremia joined by hyperchloremic metabolic acidosis seen in our patient has not been presented previously. Although it is a very rare medical condition, ROHHAD syndrome has to be considered in the differential diagnosis of any case with rapid onset obesity associated with hypothalamic-pituitary endocrine dysfunctions, and alveolar hypoventilation. [ABSTRACT FROM AUTHOR]