RESUMEN
Diabetic foot ulcer often leads to amputation, and both nutritional status and immune function have been associated with this process. We aimed to investigate the risk factors of diabetic ulcer-related amputation including the Controlling Nutritional Status score and neutrophil-to-lymphocyte ratio biomarker. We evaluated data from hospital in patients with diabetic foot ulcer, performing univariate and multivariate analyses to screen for high-risk factors and Kaplan-Meier analysis to correlate high-risk factors with amputation-free survival. Overall, 389 patients underwent 247 amputations over the follow-up period. After correction to relevant variables, we identified five independent risk factors for diabetic ulcer-related amputation: ulcer severity, ulcer site, peripheral arterial disease, neutrophil-to-lymphocyte ratio and nutritional status. Amputation-free survival was lower for the moderate-to-severe versus mild cases, for the plantar forefoot versus hindfoot location, for the concomitant peripheral artery disease versus without and in the high versus low neutrophil-to-lymphocyte ratio (all p < 0.01). The results showed that ulcer severity (p < 0.01), ulcer site (p < 0.01), peripheral artery disease (p < 0.01), neutrophil-to-lymphocyte ratio (p < 0.01) and Controlling Nutritional Status score (p < 0.05) were independent risk factors for amputation in diabetic foot ulcer patients and have predictive values for diabetic foot ulcer progression to amputation.
Asunto(s)
Diabetes Mellitus , Pie Diabético , Enfermedad Arterial Periférica , Humanos , Pie Diabético/complicaciones , Estado Nutricional , Neutrófilos , Factores de Riesgo , Linfocitos , Amputación Quirúrgica , Enfermedad Arterial Periférica/complicaciones , Estudios RetrospectivosRESUMEN
To improve the wear resistance and fatigue life of Cu alloys, surface modification by combining the magnetron sputtering of Ti film followed by vacuum thermal diffusion is always applied, where the structure and composition of the fabricated film play a determinant role on the mechanical properties. In the present work, the evolution of the layered structure and the element distribution of the formed multi-phases coating on C17200 Cu alloy are investigated by mathematical calculation based on Fick's law, and the experimental verification by the thermal diffusion of the gradient Cu-Ti film was undertaken under different temperatures and durations. The results show that the layered structure of the fabricated coating is dependent on the Cu-Ti atom concentration, the increasing time and the temperature, where a single or stratified layer is formed due to the generated Cu-Ti intermetallics for the inter-diffusion between the Cu and Ti atoms. The atom distribution by the proposed simulation method based on Fick's law corresponds to the experimental results, which can be applied to designing the structure of the modification layer.
RESUMEN
The interactions between double-stranded DNA (dsDNA) and three different kinds of surfactants, i.e., cationic, anionic, and nonionic surfactants, were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and UV-vis spectroscopy. Multilayer films composed of DNA and surfactants were prepared at gold electrode by electrostatic or hydrophobic interactions. It was found that the cationic surfactant, CTAB, can bind to DNA by electrostatic interaction, and the electron transfer resistance of CTAB-DNA complex film increases first and then decreases with CTAB concentration. The anionic surfactant, LAS, can bind to DNA but by hydrophobic interaction, and the electron transfer resistance of the complex film keeps decreasing with LAS concentration. Nonionic surfactants can also directly bind to DNA by hydrophobic interaction. All the three different kinds of surfactants can form multilayer films with DNA on the electrode surface. The chemical structure of DNA keeps unchanged during interacting with these surfactants. The binding modes of DNA with these three different kinds of surfactants were also deduced.