Spectroradiometer for Monitoring Near-Earth Ultraviolet Solar Radiation

An automated spectroradiometer for monitoring levels and doses of biologically active UV radiation has been developed. An original design of a double grating zero-dispersion monochromator is proposed. The main characteristics of the design have been tested and it has been shown that as to its parameters the spectroradiometer complies with the recommendations of the World Meteorological Organization for network meters of natural UV radiation. The results of monitoring the spectral distribution and daily doses of the solar UV radiation at the Minsk Ozone Station are presented, and the estimated values of their seasonal variations have been determined.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 2, pp. 264–270, March–April, 2005.     

High-speed photography of transient excitation

Transient excitation can cause the unstable growth and collapse of bubble nuclei, as well as enhancing the stable cavitation of larger bubbles. These unstable collapses have been photographed at 8000 f.p.s., the resulting pictures agreeing well with predicted numerical solutions. These cavities, unlike those normally studied with high-speed photography, are generated by purely acoustic methods, and so the events are as would occur during in situ acoustic cavitation.     

Barrier-breaking effects of ultrasonic cavitation for drug delivery and biomarker release

Recently, emerging evidence has demonstrated that cavitation actually creates important bidirectional channels on biological barriers for both intratumoral drug delivery and extratumoral biomarker release. To promote the barrier-breaking effects of cavitation for both therapy and diagnosis, we first reviewed recent technical advances of ultrasound and its contrast agents (microbubbles, nanodroplets, and gas-stabilizing nanoparticles) and then reported the newly-revealed cavitation physical details. In particular, we summarized five types of cellular responses of cavitation in breaking the plasma membrane (membrane retraction, sonoporation, endocytosis/exocytosis, blebbing and apoptosis) and compared the vascular cavitation effects of three different types of ultrasound contrast agents in breaking the blood-tumor barrier and tumor microenvironment. Moreover, we highlighted the current achievements of the barrier-breaking effects of cavitation in mediating drug delivery and biomarker release. We emphasized that the precise induction of a specific cavitation effect for barrier-breaking was still challenged by the complex combination of multiple acoustic and non-acoustic cavitation parameters. Therefore, we provided the cutting-edge in-situ cavitation imaging and feedback control methods and suggested the development of an international cavitation quantification standard for the clinical guidance of cavitation-mediated barrier-breaking effects.