ABSTRACT
Melorheostosis is a rare benign bone pathology involving bone dysplasia and hyperostosis. The disease can be recognized with a characteristic radiographic feature of radiopaque lesions dripping along a long bone's diaphysis. The aberrant bone formation and development manifests mainly as pain, edema, and paresthesia of the affected limb. Severe cases may report limb deformity as well as limited range of motion. Until now, there have been approximately 300 cases reported about melorheostosis worldwide and its diverse clinical picture and age distribution. In Vietnam, there is only one known case of melorheostosis discovered incidentally via radiography. The scarcity of cases presents a challenge within the medical community in recognizing and diagnosing the condition, and a delayed diagnosis can lead to severe contracture and compromised limb motility. In this article, we reported an 82-year-old case of polyostotic melorheostosis with late onset and predominant edema, affecting the sternum, the ribs, and multiple bones of the right extremities and presented our clinical approach for a geriatric patient with chronic limb edema. Our case is distinctive in terms of anatomical location as well as the predominant 20-year non-pitting edema. A prompt diagnosis was made upon the classic dripping candle wax radiographic features emphasizing the role of plain X-ray in establishing the diagnosis without extraneous utilization of other modalities and invasive procedures. Exclusion of other causes of chronic edema such as lymphadenopathy, malignancy as well as parasitic infection is of clinical importance.
ABSTRACT
A nanocomposite of titanium dioxide (TiO(2)) and polyaniline (PANi) was synthesized by in-situ chemical polymerization using aniline (ANi) monomer and TiCl(4) as precursors. SEM pictures show that the nanocomposite was created in the form of long PANi chains decorated with TiO(2) nanoparticles. FTIR, Raman and UV-Vis spectra reveal that the PANi component undergoes an electronic structure modification as a result of the TiO(2) and PANi interaction. The electrical resistor of the nanocomposite is highly sensitive to oxygen and NH(3) gas, accounting for the physical adsorption of these gases. A nanocomposite with around 55% TiO(2) shows an oxygen sensitivity of 600-700%, 20-25 times higher than that of neat PANi. The n-p contacts between TiO(2) nanoparticles and PANi matrix give rise to variety of shallow donors and acceptor levels in the PANi band gap which enhance the physical adsorption of gas molecules.
