AIM To observe the ultrastructural changes of liver tissues on normal rabbit ablated by high intensity focused ultrasound (HIFU). METHODS A single shot of 1 1MHz focused ultrasound at an intensity of 500W/cm 2 w...AIM To observe the ultrastructural changes of liver tissues on normal rabbit ablated by high intensity focused ultrasound (HIFU). METHODS A single shot of 1 1MHz focused ultrasound at an intensity of 500W/cm 2 with continuous exposure duration of 20s was applied intraoperatively in normal rabbit livers. Ultrastructural changes of the sonoablated lesion, as viewed by light and electron microscopy were observed. RESULTS Liver cells at the center of the sonoablated lesion were irreversible degeneration immediately after HIFU treatment observed by electron microscopy, although it appeared normal histologically, irregularly shaped cavities of about 0 3μm～0 5μm in diameter were found in its cytoplasm. CONCLUSION Thermal damages may be the main mechanism of HIFU ablating liver tissues and cavitation effect also plays a role in it.展开更多
The membrane microstructures and the mechanism of two coated ureas formed through solid- liquid reaction were observed by scanning electron microscope and infrared spectra, the relation of the structural characteris...The membrane microstructures and the mechanism of two coated ureas formed through solid- liquid reaction were observed by scanning electron microscope and infrared spectra, the relation of the structural characteristics with the nitrogen release feature was also discussed by combining with nitrogen dissolution in water. The results showed that the membranes were made of solid particles tightly connected to each other and were piled up layer by layer through liquid glue. Porosity and aperture of membrane were determined by compactness of piled layers and the particles in a single layer and also related to the characteristics of coating materials. Research of the infrared spectra of membrane, made of a solid powder and a liquid glue, proved that O-H on the solid surface was bonded with the double bond of the liquid glue, thus forming membrane and keeping it stable. It was found that the two coated ureas showed obvious differences in nitrogen releasing due to their membrane structures, the porosity and aperture of membrane were the critical factors for nitrogen releasing.展开更多
文摘AIM To observe the ultrastructural changes of liver tissues on normal rabbit ablated by high intensity focused ultrasound (HIFU). METHODS A single shot of 1 1MHz focused ultrasound at an intensity of 500W/cm 2 with continuous exposure duration of 20s was applied intraoperatively in normal rabbit livers. Ultrastructural changes of the sonoablated lesion, as viewed by light and electron microscopy were observed. RESULTS Liver cells at the center of the sonoablated lesion were irreversible degeneration immediately after HIFU treatment observed by electron microscopy, although it appeared normal histologically, irregularly shaped cavities of about 0 3μm～0 5μm in diameter were found in its cytoplasm. CONCLUSION Thermal damages may be the main mechanism of HIFU ablating liver tissues and cavitation effect also plays a role in it.
基金The project was supported by the National 863 Program(2001AA2 46023)the Guangdong Controlled-Release Fertilizer Project(2KB 05601N)the Guangzhou Controlled-Re-lease Fertilizer Project(2001Z02402),P.R.China.
文摘The membrane microstructures and the mechanism of two coated ureas formed through solid- liquid reaction were observed by scanning electron microscope and infrared spectra, the relation of the structural characteristics with the nitrogen release feature was also discussed by combining with nitrogen dissolution in water. The results showed that the membranes were made of solid particles tightly connected to each other and were piled up layer by layer through liquid glue. Porosity and aperture of membrane were determined by compactness of piled layers and the particles in a single layer and also related to the characteristics of coating materials. Research of the infrared spectra of membrane, made of a solid powder and a liquid glue, proved that O-H on the solid surface was bonded with the double bond of the liquid glue, thus forming membrane and keeping it stable. It was found that the two coated ureas showed obvious differences in nitrogen releasing due to their membrane structures, the porosity and aperture of membrane were the critical factors for nitrogen releasing.
