RESUMO
The electromagnetic theory of diffraction and the Babinet principle are applied to the design of artificial metasurfaces and metamaterials. A new particle, the complementary split rings resonator, is proposed for the design of metasurfaces with high frequency selectivity and planar metamaterials with a negative dielectric permittivity. Applications in the fields of frequency selective surfaces and polarizers, as well as in microwave antennas and filter design, can be envisaged. The tunability of all these devices by an applied dc voltage is also achievable if these particles are etched on the appropriate substrate.
RESUMO
OBJECTIVE: To estimate the prevalence and characteristics of urinary incontinence (UI) in the noninstitutionalized elderly population of Madrid, Spain. METHODS: We carried out a cross-sectional study in a representative sample of all community-dwelling people aged 65 or over. Subjects were interviewed in their homes. The question: Do you currently experience any difficulty in controlling your urine? . In other words, does your urine escape involuntarily? was used to identify UI. Type of UI, use of absorbents and specific drugs were also assessed, as well as consultation behavior. RESULTS: 589 persons were interviewed (response rate: 71.2%). The prevalence of UI was 15.5%. No significant difference was observed between men and women. Urge UI was the main type for men and mixed UI for women. Use of pads was referred by 20.2%. A total of 34.3% of subjects never went to the doctor for their problem (25.2% of men and 39.4% of women). CONCLUSION: Compared to other populations the overall prevalence of UI in Spanish elders living at home is relatively high. A very small difference by gender was found, although a lower response rate in women could in part explain this unexpected finding.