RESUMO
Ti-15Mo alloy samples were irradiated by pulsed Yb: YAG laser beam under air and atmospheric pressure. Calcium phosphate coatings were deposited on the irradiated surfaces by the sol-gel method. The sol was prepared from the precursors Ca (NO3)2.4H2 O and H3 PO4. The modified surfaces were submitted to heat treatment conditions at 350 and 600 °C. The results showed that the two conditions established have a sufficient energy to promote ablation on the laser beam irradiated surfaces. Likewise, it has been demonstrated the processes of fusion and fast solidification from the laser beam irradiation, under ambient atmosphere, inducing the formation of stoichiometric TiO2 and non-stoichiometric titanium oxides, including Ti3O5, TiO, Ti3O and Ti6O with different oxide percentages depending on the fluency used. Besides that, laser modification has allowed a clean and reproducible process, providing no traces of contamination, an important feature for clinical applications. The physico-chemical and morphological properties indicated the formation of a mixture of phases: calcium pyrophosphate, hydroxyapatite and ß-TCP for the procedure (PA: calcination temperature), whereas HA (hydroxyapatite) and ß-TCP (tricalcium phosphate) were obtained by the procedure (PB: calcination temperature). Therefore, it was possible to obtain a Ti-15Mo alloy surface consisted on calcium phosphate ceramics of biological interest using the procedure (PB). Thus, the laser beam irradiation associated to bioactive coatings of calcium phosphates of biological interest have shown to be promising and economically feasible for use in dental and orthopedic implants.
Assuntos
Ligas/química , Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , Transição de Fase , Materiais Revestidos Biocompatíveis/química , Prótese Dentária , Durapatita/química , Lasers , Teste de Materiais , Ortopedia , Próteses e Implantes , Propriedades de Superfície , Temperatura , TitânioRESUMO
Natural rubber latex (NRL) is a flexible biomembrane that possesses angiogenic properties and has recently been used for guided bone regeneration, enhancing healing without fibrous tissue, allergies or rejection. Calcium phosphate (Ca/P) ceramics have chemical, biological, and mechanical properties similar to mineral phase of bone, and ability to bond to the host tissue, although it can disperse from where it is applied. Therefore, to create a composite that could enhance the properties of both materials, NRL biomembranes were coated with Ca/P. NRL biomembranes were soaked in 1.5 times concentrated SBF solution for seven days, avoiding the use of high temperatures. SEM showed that Ca/P has been coated in NRL biomembrane, XRD showed low crystallinity and FTIR showed that is the carbonated type B. Furthermore, hemolysis of erythrocytes, quantified spectrophotometrically using materials (Ca/P, NRL, and NRL + Ca/P) showed no hemolytic effects up to 0.125 mg/mL (compounds and mixtures), indicating no detectable disturbance of the red blood cell membranes. The results show that the biomimetic is an appropriate method to coat NRL with Ca/P without using high temperatures, aiming a new biomembrane to improve guided bone regeneration.
Assuntos
Fosfatos de Cálcio/química , Materiais Revestidos Biocompatíveis/química , Látex/química , Materiais Revestidos Biocompatíveis/farmacologia , Hemólise/efeitos dos fármacos , HumanosAssuntos
Aneurisma Roto/complicações , Cegueira/etiologia , Aneurisma Intracraniano/complicações , Hemorragia Subaracnóidea/complicações , Hemorragia Vítrea/complicações , Aneurisma Roto/diagnóstico , Angiografia Cerebral , Embolização Terapêutica , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Hemorragia Subaracnóidea/diagnóstico , Síndrome , Hemorragia Vítrea/diagnósticoRESUMO
Central venous cannulation is a routine procedure. We describe a rare complication of internal jugular vein catheterization leading to radiculopathy of the right upper arm. MRI of the neck showed compression of the spinal cord and C2-C7 roots by the engorged veins. Digital subtraction angiography demonstrated a fistula between subclavian artery and internal jugular vein. The fistula was successfully occluded by stent placement in the artery.