For the first time, 3D printed metal-pipe rectangular waveguides (MPRWGs) have been demonstrated in the WM-380 (500–750 GHz) and WM-250 (750 GHz–1.1 THz) waveguide bands. The ultra-high spatial ...resolution offered by the new RECILS additive manufacturing technology enables the precision fabrication of these prototype MPRWGs at such high frequencies. This enabling technology avoids the need for access to expensive microfabrication resources and, thus, opens up the terahertz spectrum to the low-cost manufacture of passive components.
This study was carried out in order to clarify the effects of rapid intravenous urography performed twice at a three-day interval with contrast medium on renal function and morphologic change in ...normal rabbits as a means to observe progress or to reexamine patients. The ionic high-osmolal amidotrizoate, non-ionic low-osmolal iopamidol, and ionic low-osmolal ioxaglate were used. A second urography was performed and curves of kidney density plotted against time and nephrograms were obtained. Serum BUN and creatinine were measured, and the kidneys were removed for histologic observations. Following amidotrizoate administration, curves of kidney density showed significantly slower clearance than with iopamidol and ioxaglate. Nephrograms at 40 seconds showed that opacification of the renal pelvis and urinary tracts also was poor. Serum creatinine following the second administration of amidotrizoate was significantly higher than the values before and at the first urography, and both serum BUN and creatinine were significantly higher than they were after iopamidol and ioxaglate. Although light microscopic changes were obscure, marked changes were observed by electron microscopy. In conclusion, intravenous urography conducted twice at a close interval with amidotrizoate induces impairment of glomerular function and morphologic change.