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Irregular Surface (irregular + surface)
Selected AbstractsNEW APPLICATION OF NARROW BAND IMAGING FOR CHOLANGIOPANCREATOSCOPYDIGESTIVE ENDOSCOPY, Issue 2007Mitsuhiro Kida The usefulness of narrow band imaging (NBI), which is based on the principle that the depth of light penetration depends on its wavelength, has been accepted for evaluating malignant or benign lesions in the pharynx, the upper, and lower gastrointestine. The purpose of the present paper was to investigate NBI for diagnosing biliopancreatic disease. Using NBI it has become easy to detect the surface microstructure of biliary mucosa and subjacent vascular network of the bile duct, and inflammatory scarring stenosis is visualized as a whitish scar and multiple inflammatory red spots. However, bile duct cancer was detected as a stenosis with abnormal subjacent vessels and irregular surface. Concerning pancreatic duct, NBI has clearly shown vascular network and spreading of branch-type intraductal papillary mucinous neoplasm to the main pancreatic duct. In contrast, bile juice has been detected as red fluid and bleeding as black red. Therefore, it is important to flush the biliary system before observing with NBI. [source] Wind erosion characteristics of Sahelian surface typesEARTH SURFACE PROCESSES AND LANDFORMS, Issue 12 2010Thomas Maurer Abstract The assessment of wind erosion magnitudes for a given area requires knowledge of wind erosion susceptibilities of the dominant local surface types. Relative wind erosion potentials of surfaces can hardly be compared under field conditions, as each erosion event is unique in terms of duration, intensity and extent. The objective of this study was to determine and compare relative wind erosion potentials of the most representative surface types over a transect comprising most parts of southwestern Niger. For this purpose, mobile wind tunnel experiments were run on 26 dominant surface types. The effects of surface disturbance were additionally determined for 13 of these surfaces. The results, namely measurements of wind fields and mass fluxes, can be classified according to specific surface characteristics. Three basic surface groups with similar emission behaviour and aerodynamic characteristics were identified: (1) sand surfaces, (2) rough stone surfaces and (3) flat crusted surfaces. Sand surfaces feature a turbulent zone close to the surface due to the development of a saltation layer. Their surface roughness is medium to high, as a consequence of the loss of kinetic energy of the wind field to saltating particles. Sand surfaces show the highest mass fluxes due to the abundance of loose particles, but also fairly high PM10 fluxes, as potential dust particles are not contained in stable crusts or aggregates. Rough stone surfaces, due to their fragmented and irregular surface, feature the highest surface roughness and the most intense turbulence. They are among the weakest emitters but, due to their relatively high share of potential dust particles, PM10 emissions are still average. Flat crusted surfaces, in contrast, show low turbulence and the lowest surface roughness. This group of surfaces shows rather heterogeneous mass fluxes, which range from moderate to almost zero, although the share of PM10 particles is always relatively high. Topsoil disturbance always results in higher total and PM10 emissions on sand surfaces and also on flat crusted surfaces. Stone surfaces regularly exhibit a decrease in emission after disturbance, which can possibly be attributed to a reorganization which protects finer particles from entrainment. The results are comparable with field studies of natural erosion events and similar wind tunnel field campaigns. The broad range of tested surfaces and the standardized methodology are a precondition for the future regionalization of the experimental point data. Copyright © 2010 John Wiley & Sons, Ltd. [source] Effects of chitosan solution concentration and incorporation of chitin and glycerol on dense chitosan membrane propertiesJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2007Paula Rulf Marreco Dallan Abstract The aim of this work was to perform a systematic study about the effects induced by chitosan solution concentration and by chitin or glycerol incorporation on dense chitosan membranes with potential use as burn dressings. The membrane properties analyzed were total raw material cost, thickness, morphology, swelling ratio, tensile strength, percentage of strain at break, crystallinity, in vitro enzymatic degradation with lysozyme, and in vitro Vero cells adhesion. While the use of the most concentrated chitosan solution (2.5% w/w) increased membrane cost, it also improved the biomaterial mechanical resistance and ductility, as well as reduced membrane degradation when exposed for 2 months to lysozyme. The remaining evaluated properties were not affected by initial chitosan solution concentration. Chitin incorporation, on the other hand, reduced the membranes cost, swelling ratio, mechanical properties, and crystallinity, resulting in thicker biomaterials with irregular surface more easily degradable when exposed to lysozyme. Glycerol incorporation also reduced the membranes cost and crystallinity and increased membranes degradability after exposure to lysozyme. Strong Vero cells adhesion was not observed in any of the tested membrane formulations. The overall results indicate that the majority of the prepared membranes meet the performance requirements of temporary nonbiodegradable burn dressings (e.g. adequate values of mechanical resistance and ductility, low values of in vitro cellular adhesion on their surfaces, low extent of degradation when exposed to lysozyme solution, and high stability in aqueous solutions). © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007 [source] Cyanoacrylate glue for corneal perforations: a description of a surgical technique and a review of the literatureCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 6 2000Brendan Jt Vote MBBS ABSTRACT The effective early application of a cyanoacrylate glue corneal patch can aid in the management of small corneal perforations, corneal melts and wound leaks. Their use gives improved visual outcomes with reduced enucleation rates (6%vs 19%). It may also avoid the need for tectonic penetrating keratoplasty. Cyanoacrylate glue prevents re-epithelialization into the zone of damaged and naked stroma and prevents the development of the critical setting for collagenase production that leads to stromal melting. Cyanoacrylates also have significant bacteriostatic activity against Gram-positive organisms. We describe a simple and easily reproducible method of cyanoacrylate corneal patch application, with neglible risk of inadvertent glue complications. It has the further advantage of a smooth corneal surface rather than an irregular surface as often occurs with direct application methods. With corneal application, the major concern is toxicity of cyanoacrylates through direct contact with the corneal endothelium and lens. Fibrin glues may be less toxic; however, they are not as readily available. The longer alkyl chains of currently available cyanoacrylate glues (e.g. Histoacryl) slows degradation significantly, limiting accumulation of histotoxic by-products to amounts that can be effectively eliminated by tissues. Vigilance in monitoring for infection/corneal infiltrate is necessary at all times, especially when the glue has been present for more than 6 weeks. Corneal patching with cyanoacrylate glue is a temporizing procedure only, buying time to allow healing secondary to medical treatment of the underlying condition, or allowing surgery to be elective and under more optimal conditions once inflammation has been reduced and the integrity of the globe restored. [source] Case of mesothelioma of the tunica vaginalis testis with characteristic findings on ultrasonography and magnetic resonance imagingINTERNATIONAL JOURNAL OF UROLOGY, Issue 11 2000Masafumi Fujisaki Abstract A case of mesothelioma of the right tunica vaginalis testis in a 32-year-old man is reported. Trans-scrotal ultrasonography revealed hydrocele and multiple nodular masses measuring 1.0,4.5 cm in size attached to the parietal vaginal layer. Magnetic resonance imaging demonstrated more clearly nodular masses with irregular surfaces lined on the hydrocele cavity. Histologic diagnosis of the tumor when orchiectomized was mesothelioma. The patient has been free of disease for approximately 3 years since the treatment. [source] | ||||||||||