RESUMO
Bulk metallic glasses (BMGs) possess attractive properties for biomedical applications, including high strength, hardness and corrosion resistance, and low elastic modulus. In this study, we conduct rotating beam fatigue tests on Pd43Ni10Cu27P20 bulk metallic glass in air and Eagle's medium (EM) and measure the corrosive resistance of the alloy by submersion in acidic and basic electrolytes. Fatigue results are compared to those of commonly used biometals in EM. Rotating beam fatigue tests conducted in air and in Eagle's medium show no deterioration in fatigue properties in this potentially corrosive environment out to 10(7) cycles. A specimen size effect is revealed when comparing fatigue results to those of a similar alloy of larger minimum dimensions. Corrosion tests show that the alloy is not affected by highly basic (NaOH) or saline (NaCl) solutions, nor in EM, and is affected by chlorinated acidic solutions (HCl) to a lesser extent than other commonly used biometals. Corrosion in HCl initiates with selective leaching of late transition metals, followed by dissolution of Pd.
Assuntos
Vidro/química , Teste de Materiais , Paládio/química , Estresse Mecânico , Ligas/química , Varredura Diferencial de Calorimetria , Corrosão , Cristalização , Imersão , Espectrofotometria Atômica , Temperatura , Difração de Raios XRESUMO
The objective of this study was to assess the efficacy of five types of disposable protective eyewear devices, to determine variables affecting compliance with the use of protective eyewear, and to determine the frequency of subclinical eye splatter. One hundred volunteer health care providers were assigned to one of five study eyewear groups and given a protective eyewear device to use for 2 weeks in an urban teaching referral center. Questionnaires were used to survey eyewear habits and other variables before the study. The devices were determined to be 88% effective overall, and there was no statistically significant difference between groups. The incidence of subclinical splatter was 50%. Even though disposable eyewear devices providing full frontal and lateral eye coverage are effective in preventing eyesplatter, the incidence of eyesplatter among health care providers working in nonsurgical areas is more common than previously assumed because of the lack of recognition of splatter (subclinical splatter) by the workers.
Assuntos
Equipamentos Descartáveis , Dispositivos de Proteção dos Olhos , Infecções por HIV/prevenção & controle , Pessoal de Saúde , Doenças Profissionais/prevenção & controle , Adulto , Atitude do Pessoal de Saúde , Comportamento do Consumidor , Desenho de Equipamento , Feminino , Infecções por HIV/transmissão , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/etiologia , Fatores de RiscoRESUMO
Seven human immunodeficiency virus-(HIV) positive patients with biopsy proved extensive facial molluscum contagiosum were treated with trichloroacetic acid peels. Peels were performed with 25 to 50% trichloroacetic acid (average 35%) and were repeated every 2 weeks as needed. A total of 15 peels were performed with an average reduction in lesion counts of 40.5% (range 0 to 90%). No spread of molluscum lesions, scarring, or secondary infection developed at 2 months' follow-up. Trichloroacetic acid peeling in concentrations of 35% or less appears to be a safe, effective, adjuvant therapy in the treatment of extensive molluscum contagiosum in immunocompromised patients.