Accelerated Escherichia coli inactivation in the dark on uniform copper flexible surfaces.

The bacterial inactivation of Escherichia coli on Cu/CuO-polyester surfaces prepared by direct current magnetron sputtering was investigated in the dark and under actinic light (360 nm≤ λ ≤ 720 nm; 4.1 mW/cm(2)) as used commonly in hospital facilities. In the dark, complete bacterial inactivation (6log10 reduction) was observed within 150 min and under actinic light within 45 min. Sputtered samples led to nanoparticulate uniform Cu/CuO films ~70 nm thick. The deposition rate used was 2.2×10(15) atoms/cm(2) s as determined by profilometry. X-ray fluorescence was used to determine the sample Cu-content and transmission electron microscopy determined Cu-particles ~20 ± 5 nm in size. The film optical absorption was observed to increase with Cu-content of the sample by diffuse reflection spectroscopy. The bacterial inactivation involved redox processes between Cu/CuO-polyester and the bacteria as observed by x-ray photoelectron spectroscopy. During sample recycling, the amount of Cu-release was determined by inductively coupled plasma-mass spectroscopy. The values required for E. coli inactivation were below the cytotoxicity level threshold allowed for mammalian cells. The E. coli inactivation by Cu/CuO-polyester seems to involve an oligodynamic effect since bacterial inactivation was achieved at very low Cu-concentrations.

Association of selenium with thyroid volume and echostructure in 35- to 60-year-old French adults.

OBJECTIVE: To investigate the relationship between selenium status, thyroid Volume and gland echostructure. DESIGN: Cross-sectional. METHODS: In 792 men (45-60 Years) and 1108 women (35-60 Years) from the SU.VI.MAX study, thyroid Volume and gland echostructure were determined ultrasonographically. At baseline, thyrotropin, free thyroxine, selenium, zinc, alpha-tocopherol, beta-carotene, retinol, urinary iodine and thiocyanate concentrations were measured. Alcohol consumption, smoking, and menopausal status were assessed by a questionnaire. A stepwise linear and a logistic regression model were used, adjusting for antioxidant vitamins, trace elements status and age. RESULTS: In women, there was an inverse association between selenium status and thyroid Volume (P=0.003). A protective effect of selenium against goiter (odds ratio (OR)=0.07, 95% confidence interval (CI)=0.008-0.6) and thyroid tIssue damage (OR=0.2, 95% CI=0.06-0.7) was observed. There was no evidence of an association between menopausal status and other antioxidant elements, thyroid Volume or thyroid hypoechogenicity. Smoking, but not alcohol consumption, was associated with an increased risk of thyroid enlargement in women (OR=3.94, 95% CI=1.64-9.48). No association between thyroid Volume, thyroid structure or selenium was found in men. CONCLUSION: Our findings suggest that selenium may protect against goiter. Selenium was related to thyroid echostructure, suggesting it may also protect against autoimmune thyroid disease.