Surface encrustation by minerals, which impedes cellular metabolism, is a potential hazard for microbes. The reduction of U(VI) to U(IV) by Shewanella oneidensis strain MR-1 leads to the precipitation of the mineral uraninite, as well as a non-crystalline U(IV) product. The wild-type (WT) strain can produce extracellular polymeric substances (EPS), prompting precipitation of U some distance fro...

Microorganisms have been observed to oxidize Fe(II) at neutral pH under anoxic and microoxic conditions. While most of the mixotrophic nitrate-reducing Fe(II)-oxidizing bacteria become encrusted with Fe(III)-rich minerals, photoautotrophic and microaerophilic Fe(II) oxidizers avoid cell encrustation. The Fe(II) oxidation mechanisms and the reasons for encrustation remain largely unresolved. Her...

Duguid (1946, 1952) extended Rokitansky's earlier observations by suggesting that encrustation of fine platelet deposits and films of fibrin on the endothelium provokes an inflammatory response that results in organization by scarring. This view has been modified by supposing that local fibrinolytic activity in the arterial wall may control the equilibrium between encrustation and solution of f...

The present paper addresses the problem of the encrustation of a high spatial resolution imagette into an image of lower resolution of larger geographical extent. A method is proposed which makes use of the high resolution content of the imagette to simulate the high resolution content in the outer periphery of the imagette area. The originality of this approach lies into its ability to simulta...

OBJECTIVES To present our series of patients with ureteral stent encrustation and give indwelling times and management. Encrustation is one of the most serious complications of ureteral stents. METHODS A retrospective review was undertaken of all encrusted stents during a 4-year period. The inclusion criterion was a stent that required some form of intervention above the ureteral orifice to r...

background ureteral stents are widely used in many urologic practices. however, stents can cause significant complications including migration, fragmentation, and encrustation and it may possibly be forgotten. successful management of a retained, encrusted stent requires combined endourological approaches. objectives to present our experience with the approaches for treating forgotten ureteral ...

Colonization of urinary catheters by bacteria which produce urease leads to an increase in urine pH, followed by deposition of the minerals struvite and hydroxyapatite. Adhesion of these encrusting deposits can be reduced, but not prevented, by using catheters with a smooth surface finish. Chemical methods for preventing encrustation are not completely satisfactory. A better way of preventing e...

Blockages of the ureter, e.g. due to calculi (kidney stones), can result in an increase in renal pelvic pressure. This may be relieved by inserting a stent (essentially a permeable hollow tube). However, a number of complications are associated with stent use. Stents can result in reflux (backflow of urine along the ureter), which will promote recurrent urinary infection and possible renal pare...

Copyright © 2013, Nephrology and Urology Research Center; Licensee Kowsar Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Dear Editor, Catheter encrustation is a chall...