Ultrasound ablation

For the ultrasound ablation two methods are currently available - extracorporeal (transcutaneous) and direct (or percutaneous) via a needle-like applicator. The term high intensity focused ultrasound should be reserved for describing the extracorporeal method. Direct ultrasound ablation means the replacement of an applicator via a percutaneous or laparoscopic insertion. 

Hanajiri K, Maruyama T, Kaneko Y, Mitsui H, Watanabe S, Sata M, Nagai R, Kashima T, Shibahara J, Omata M, Matsumoto Y (2006) Microbubble-induced increase in ablation of liver tumors by high-intensity focused ultrasound. Hepatology Research 36 308-314. 

The examinations are performed in real time and can visualize motion (30 frames per second or even more) respectively, needle biopsies and tissue ablation procedures are often performed under the guidance of ultrasound imaging. 

High-frequency or diagnostic ultrasound in clinical imaging (3-10 MHz) Medium-frequency or therapeutic ultrasound in physical therapy (0.7-3.0 MHz) Low-frequency or power ultrasound for lithotripsy, cataract emulsification, liposuction, tissue ablation, cancer therapy, dental descaling, and ultrasonic scalpels (18-100 kHz)... 

Frontrunner blunt microdissection catheter Radiofrequency ablation with optical Coherence reflectometry guidance Laser guidewire High frequency ultrasound... 

Cedrone, A., Pompili, M., Sallustio, G., Lorenzelli, G.P., Gasbarrini, G., Rapaccini, G.L. Comparison between color power Doppler ultrasound with echo-enhancer and spiral computed tomography in the evaluation of hepatocellular carcinoma vascularization before and after ablation procedures. Amer. J. Gastroenterol. 2001 96 1854-1859... 

In addition to chemical methods variety of physical methods has been employed for the synthesis of AuNPs. UV irradiation is used to improve the quality of the AuNPs when it is used in synergy with micelles or seeds [32,33], Near-IR laser irradiation provokes an enormous size growth of thiol-stabilized AuNPs [34], The presence of an ultrasonic field (200 kHz) allowed the control of the rate of AuC14" reduction in an aqueous solution containing only a small amount of 2-propanol and the sizes of the formed AuNPs are controlled by varying the parameters such as the temperature of the solution, the intensity of the ultrasound, and the positioning of the reactor [35,36], Sonochemistry was also used for the synthesis of AuNPs within the pores of silica and for the synthesis of Au/Pd bimetallic particles [37,38], Radiolysis has been used to control the size of AuNPs [39], Laser photolysis has been used to form AuNPs in block copolymer micelles. Laser ablation is another technique of AuNP synthesis that has been used under various conditions whereby size control can be induced by the laser [40,41],... 

Serial measurement of Tg is most useful in detecting recurrence of DTC following surgical resection or radioactive iodine ablation. Tg determination is used as an adjunct to ultrasound and scanning. Assessment of serum Tg also aids in the management of infants with congenital hypothyroidism, All patients with hyperthyroidism should have elevated Tg low concentrations of Tg may be an indication that thyrotoxicosis factitia is present. 

MRI-guided focused ultrasound fibroid ablation is the newest of the non-invasive techniques and is still in the experimental stages. The ultrasound waves are directed from a transducer into a small focal volume. The tissue at the focal point receives condensed energy and increases in temperature, causing protein denaturation, cell death and coagu-lative necrosis. While a commercial device is available, long term data on this procedure does not yet exist [45]. 

Vacuum is effective in collecting ISF firom skin that has been mechanically penetrated or had the stratum comeum removed. As with blood collection studies, large site-to-site and person-to-person variability is observed. A large vacuum headspace in the collection devise results in a decrease in volume due to evaporation and an increase in analyte concentrations. Outgassing of dissolved gas in the ISF and leaks between the skin and vacuum source lead to the formation of bubbles in the ISF stream over time. The application of one-half atmosphere vacuum through a harvesting head with an aperture of 2.5 mm over a 1 mm pattern of micropores produced by laser ablation of a black dye yields straw-colored interstitial fiuid at fiow rates of 5-15 pL/h for several days [4]. Vacuum collection over a much larger area (about 1 cm ) is required to collect similar amounts of ISF from low-frequency ultrasound-treated skin [8]. 

Many methods have been reported for production of nanodiamonds (NDs) such as laser ablation, " plasma-assisted chemical vapor deposition," autoclave synthesis from supercritical fluids, ion irradiation of graphite, chlorination of carbides, electron irradiation of carbon onions, and ultrasound cavitation. Smaller NDs can be prepared by detonation processes that yield aggregates of NDs with sizes of 4-5 nm embedded in a detonation soot composed of other carbon allotropes and impurities. An explosive mixture having an overall negative oxygen balance provides a source of both carbon and energy for the conversion. Because of their small size (2-10 nm) detonation NDs have also been referred to as ultradispersed, nanocrystalline... 

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