Diabetic foot disease and oedema

Diabetic foot ulcers (DFUs) are common and disabling, giving rise to significant morbidity and mortality as well as worldwide socioeconomic problems. Despite treatment, DFUs readily become chronic wounds and may lead to major lower limb amputations. The pathogenesis of DFUs is complex and the main aetiologies are peripheral neuropathy, ischaemia from peripheral arterial disease and biomechanical abnormalities. Microvascular disease is also a significant problem for people with diabetes and contributes to foot ulceration. Successful management of DFUs consists of debridement, infection control, the use of offloading appliances and revascularisation where necessary. Foot ulcers are usually associated with infection and inflammation which lead to surrounding oedema of the foot. Standard offloading devices such as total contact casts and removable cast walkers do not actively reduce foot oedema. There is promising evidence that active oedema reduction by intermittent pneumatic compression in the diabetic foot improves ulcer healing. The objective of this article is to review the association of foot oedema and DFUs, including the role of appliances which reduce oedema. The information presented is vital to those involved in the management of DFUs. © The Author(s) 2012

Tipping the balance: theoretical interrogation of divergent extended heterolytic fragmentations.

Herein we interrogate a type of heterolytic fragmentation reaction called a 'divergent fragmentation' using density functional theory (DFT), natural bond orbital (NBO) analysis, ab initio molecular dynamics (AIMD), and external electric field (EEF) calculations. We demonstrate that substituents, electrostatic environment and non-statistical dynamic effects all influence product selectivity in reactions that involve divergent fragmentation pathways. Direct dynamics simulations reveal an unexpected post-transition state bifurcation (PTSB), and EEF calculations suggest that some transition states for divergent pathways can, in principle, be selectively stabilized if an electric field of the correct magnitude is oriented appropriately

Attenuation of stress waves in single and multi-layered structures

Analytical and experimental studies were made of the attenuation of the stress waves during passage through single and multilayer structures. The investigation included studies on elastic and plastic stress wave propagation in the composites and those on shock mitigating material characteristics such as dynamic stress-strain relations and energy absorbing properties. The results of the studies are applied to methods for reducing the stresses imposed on a spacecraft during planetary or ocean landings

Optimum design of structures of composite materials in response to aerodynamic noise and noise transmission

Elastic wave propagation and attenuation in a model fiber matrix was investigated. Damping characteristics in graphite epoxy composite materials were measured. A sound transmission test facility suitable to incorporate into NASA Ames wind tunnel for measurement of transmission loss due to sound generation in boundary layers was constructed. Measurement of transmission loss of graphite epoxy composite panels was also included

Juncture stress fields in multicellular shell structures. Volume III - Stresses and deformations on fixed-edge segmental conical shells Final report

Equations for thin elastic conical shells and digital program for analysis of stress and deformation on fixed edge segmental conical shells - solution by finite difference techniqu

Double-dot charge transport in Si single electron/hole transistors

We studied transport through ultra-small Si quantum dot transistors fabricated from silicon-on-insulator wafers. At high temperatures, 4K<T<100K, the devices show single-electron or single-hole transport through the lithographically defined dot. At T<4K, current through the devices is characterized by multidot transport. From the analysis of the transport in samples with double-dot characteristics, we conclude that extra dots are formed inside the thermally grown gate oxide which surrounds the lithographically defined dot.Comment: 4 pages, 5 figures, to appear in Appl. Phys. Let