The initial design criteria in the choice of indwelling materials for medical and dental purposes may be pragmatic, and based on the necessary mechanical properties required to fashion a functional device. Orthopedic implants require strong materials for weight-bearing, and articulating surfaces such as joints require durability and resistance to wear. Stents and shunts require flexibility and patency, and sutures require a high tensile strength yet also must be flexible enough for intricate manipulation. As the devices became more sophisticated and developments in materials science provided more options for manufacture, implants are being used more frequently and with longer anticipated lifetimes. Concurrently, the design process increasingly incorporated biocompatibility and comfort into the design criteria. However, with longer lifetimes, the more frequent use of invasive surgical procedures involving indwelling devices and biologically-friendly materials, there has been a rise in the number of incidences of device-related infection. Urinary catheters have been estimated to account for 30% of all nosocomial infections [1]. Between 66 and 88% of these occur after urinary catheterization [2]. It is also reported that almost 100% of catheterized patients develop an infection in an openly draining indwelling catheter which has been in place for four days or more [2]. For some procedures, such as orthopedic joint arthroplasties, the diagnosed surgical site infection rates are relatively low (between 1% and 2%; [3]); however, the increasing number of patients undergoing joint-replacement surgery translates to large numbers of patients afflicted with the consequences of complicating infections per year. Furthermore, infection of artificial joints can be devastating, since oral or IV antibiotic therapy frequently fails to resolve the infection, with the only remaining course of action being surgical debridement or partial or total revision. These two examples, the first with very high numbers of patients but of lesser severity in terms of impact to the individual, and the second, low numbers but severe patient impact, reflect the incentive to pursue a third design criteria—that of infection resistance—into materials and devices [4]. In the following sections we will discuss the role of bacterial biofilms in infection, and the growing literature highlighting biofilms as an important cause of device-related infection.
Norfolk 1: Norwich and North-East and its companion, Norfolk 2: North-West and South, aim to provide a lively and uniquely comprehensive survey of the architectural treasures of Norfolk. Extensively revised and expanded, these new editions of Sir Nikolaus Pevsner's original volumes bring together the latest research on a county which has some of the most attractive buildings in England. The gazetteer is enhanced by an introduction which provides a perceptive overview of the region's architectural inheritance, and is illustrated by numerous text figures, maps and 130 photographs (many specially commissioned). Pre-eminent in this volume is the city of Norwich, rich in major buildings of outstanding quality, from Norman cathedral and castle to twentieth-century city hall and university. Supreme among the ports described in this volume is the medieval walled town of Great Yarmouth, whose highly individual history and buildings are here examined in detail for the first time. There are also full descriptions of many appealing market towns, whilst the rest of the county is revealed through succinct accounts of its parish churches and less well-known buildings. Abbey ruins, brick eighteenth-century farmhouses and estate cottages in quiet inland villages contrast with coastal fishing settlements and resorts. Great barns testify to the significance of agriculture. Country houses range from the magnificent Jacobean Blickling Hall to seaside extravaganzas by Lutyens. Detailed indexes make this not only an essential reference book, but also a guide book for anyone interested in the rich region of Norfolk.
This will help us customize your experience to showcase the most relevant content to your age group
Please select from below
Login
Not registered?
Sign up
Already registered?
Success – Your message will goes here
We'd love to hear from you!
Thank you for visiting our website. Would you like to provide feedback on how we could improve your experience?
This site does not use any third party cookies with one exception — it uses cookies from Google to deliver its services and to analyze traffic.Learn More.