35 research outputs found
Computing, Design, Art: Reflections on an Innovative Moment in History
The paper is concerned with the role of art and design in the history and philosophy of computing. It offers insights arising from research into a period in the 1960s and 70s, particularly in the UK, when computing became more available to artists and designers, focusing on John Lansdown (1929-1999) and Bruce Archer (1922-2005) in London. Models of computing interacted with conceptualisations of art, design and related creative activities in important ways
Effect of low-frequency, low-amplitude magntic fields on the permeability of cationic liposomes entrapping carbonic anhydrase.I. Evidence for charged lipid involvement.
The influence of low frequency (4–16 Hz), low amplitude (25–75 μT) magnetic fields on the diffusion processes in enzyme-loaded unilamellar liposomes as bioreactors was studied. Cationic liposomes containing dipalmitoylphosphatidylcholine, cholesterol, and charged lipid stearylamine (SA) at different molar ratios (6:3:1 or 5:3:2) were used. Previous kinetic experiments showed a very low self-diffusion rate of the substrate p-nitrophenyl acetate (p-NPA) across intact liposome bilayer. After 60 min of exposure to 7 Hz sinusoidal (50 μT peak) and parallel static (50 μT) magnetic fields the enzyme activity, as a function of increased diffusion rate of p-NPA, rose from 17 ± 3% to 80 ± 9% (P < .0005, n = 15) in the 5:3:2 liposomes. This effect was dependent on the SA concentration in the liposomes. Only the presence of combined sinusoidal (AC) and static (DC) magnetic fields affected the p-NPA diffusion rates. No enzyme leakage was observed. Such studies suggest a plausible link between the action of extremely low frequency magnetic field on charged lipids and a change of membrane permeability
Effects of 2.45 GHz microwave fields on liposomes entrapping glycoenzyme ascorbate oxidase: evidence for oligosaccharide side chains involvement
Previous observations reported by our group indicate that 2.45 GHz microwave fields at specific absorption rate (SAR) of 5.6 W/kg reduce the enzyme activity rate of ascorbate oxidase (AO) trapped in liposomes. In this study, we report dose-response studies on these AO containing liposomes irradiated at different SAR values (1.4, 2.8, 4.2, and 5.6 W/kg). No response was observed for SAR below 5.6 W/kg. Liposomes entrapping functional AO in its deglycated form (AO-D) were also used. In this case, no MW related enzyme activity changes were observed, demonstrating a direct involvement of oligosaccharide chains of AO. Furthermore, the catalytic properties of both AO and AO-D were not impaired by MW irradiation, neither in homogeneous solution nor loaded in liposomes, excluding possible changes in the conformation of enzyme as a mechanism. Our results suggest that the oligosaccharide chains of AO are critical to elicit the microwave observed effects on lipid membrane
Effect of low frequency, low amplitude magnetic fields on the permeability of cationic liposomes entrapping carbonic anhydrase. I-Evidence for charged lipid involvement
A Theoretical and Experimental Methodology for Identifying Dielectric Models of Biological Cells
Permeability changes of cationic liposomes loades with carboniv anhydrase induced by millimeter waves radiation
L'idatidosi vertebrale:stato delle attuali conoscenze della lesione e presentazione di un caso clinico particolare
Vertebral hydatidosis is a rare localization of echinococcosis. In fact, its incidence is less than 1% of the cases in the literature. The authors report a personal observation and describe main features of the disease