RESUMO
Here, we report development of the galvanostatic Fourier transform electrochemical impedance spectroscopy (FTEIS), which monitors impedance of electrochemical reactions activated by current steps. We first derive relevant relations for potential change upon application of a step current, obtain impedances theoretically from the relations by simulation, and verify them with experimental results. The validity of the galvanostatic FTEIS technique is demonstrated by measuring impedances of a semiconductive silicon wafer using the conventional frequency response analysis (FRA), the potentiostatic FTEIS, and the galvanostatic FTEIS methods, and the results are in excellent agreement with each other. This work is significant in that the galvanostatic FTEIS would allow one to record impedance changes during charge/discharge cycles of secondary batteries and fuel cells as well as electrochemically irreversible systems which may produce noise level chronoamperometric currents by potentiostatic techniques.
RESUMO
A membrane bioreactor (MBR) integrates process such as membrane filtration and biological treatment of activated sludge. However, organic, inorganic and biological matters cause membrane fouling, which seriously affects membrane performance. The goal of this study was to evaluate the biofouling inhibition capacity of raffinose during the MBR process. The results showed that 0-1,000 µM raffinose significantly reduced the formation of the P. aeruginosa and S. aureus co-culture biofilm by about 25-52 % in a concentration-dependent manner. In addition, the effect of raffinose on the microfiltration membrane biofilm was tested in a flow reactor and lab-scale MBR unit. The results showed that the co-culture biofilm and transmembrane pressure were decreased by raffinose treatment compared to those by furanone C-30 treatment. These results clearly demonstrated that raffinose, broad-spectrum biofilm inhibitor, inhibits biofilm formation in mixed cultures and could be used to mitigate biofouling in MBR processes.
Assuntos
Incrustação Biológica , Staphylococcus aureus , Biofilmes , Incrustação Biológica/prevenção & controle , Reatores Biológicos , Técnicas de Cocultura , Galactosídeos , Membranas Artificiais , Rafinose , EsgotosRESUMO
OBJECTIVES: To analyze quality of life in people with symptomatic spine osteoarthritis (OA) using the results of a cross-sectional, nationwide survey. MATERIALS AND METHODS: This study used data from the Fifth Korean National Health and Nutrition Examination Survey (KNHANES V-5; 2010-2012). After excluding ineligible subjects, the total number of subjects in the study was 8,963, including 4,091 males and 4,872 females. All participants reported disabilities related to spine OA. Plain radiographs of the spine were taken for all participants. RESULTS: Age, sex, smoking, drinking, education, and income level were significantly related to spine OA morbidity (P<0.05). OA morbidity was significantly higher in female ex-smokers (OR; 2.94, P<0.05). Quality of life (EQ-5D: L1~5) was significantly compromised in the group with spine OA compared to the group without spine OA (P<0.05). Overall, LQ 1, 2, 3, 4, and 5 domain scores were significantly higher in the group with spine OA (P<0.05). In the group with spine OA, quality of life was reduced on more than three questions for 34.3% of the group (EQ-5D: grade≥2); on two questions, for 18.5% of the group; and on one question, for 11.1% of the group. Mental stress, melancholy, and suicidal thinking were also more common in the group with spine OA (P<0.05). The group with radiographic spine OA but without symptoms did not have compromised EQ-5D scores, whereas the group with radiographic OA and symptoms showed a significantly reduced quality of life. CONCLUSIONS: Quality of life was significantly reduced in the group with symptomatic spine OA in a large cross-sectional analysis. Physicians should consider quality of life in the treatment of patients with spine OA.
Assuntos
Osteoartrite da Coluna Vertebral/etiologia , Qualidade de Vida , Fumar , Atividades Cotidianas , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Osteoartrite da Coluna Vertebral/diagnóstico por imagem , Osteoartrite da Coluna Vertebral/epidemiologia , Radiografia , República da Coreia , Autocuidado/estatística & dados numéricos , Fumar/epidemiologia , Fatores SocioeconômicosRESUMO
The purpose of this study was to fabricate BMP-2-immobilized porous poly(lactide-co-glycolide) (PLGA) microspheres (PMS) modified with heparin for bone regeneration. A fluidic device was used to fabricate PMS and the fabricated PMS was modified with heparin-dopamine (Hep-DOPA). Bone morphogenic protein-2 (BMP-2) was immobilized on the heparinized PMS (Hep-PMS) via electrostatic interactions. Both PMS and modified PMS were characterized using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). MG-63 cell activity on PMS and modified PMS were assessed via alkaline phosphatase (ALP) activity, calcium deposition, and osteocalcin and osteopontin mRNA expression. Immobilized Hep-DOPA and BMP-2 on PMS were demonstrated by XPS analysis. BMP-2-immobilized Hep-PMS provided significantly higher ALP activity, calcium deposition, and osteocalcin and osteopontin mRNA expression compared to PMS alone. These results suggest that BMP-2-immobilized Hep-PMS effectively improves MG-63 cell activity. In conclusion, BMP-2-immobilized Hep-PMS can be used to effectively regenerate bone defects.