this article studied static deflection, natural frequency and nonlinear vibration of a clamped-clamped microbeam under discontinues electrostatic actuation. the electrostatic actuation was induced by applying ac-dc voltage between the microbeam and electrode plate. in contrast to previous works, it was assumed that length of the electrode plate was smaller than that of the microbeam. in additio...

In order to study the radiobiological effects of low dose radiation, microbeam irradiation facilities have been developed in the world. This type of facilities now becomes an essential tool for studying bystander effects and relating signaling phenomena in cells or tissues. This review introduces you available microbeam facilities in Japan and in China, to promote radiobiology using microbeam p...

The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the elect...

A novel neutron microbeam is being developed at the Radiological Research Accelerator Facility (RARAF) of Columbia University. The RARAF microbeam facility has been used for studies of radiation bystander effects in mammalian cells for many years. Now a prototype neutron microbeam is being developed that can be used for bystander effect studies. The neutron microbeam design here is based on the...

To study the radiation effect of cosmic heavy ions of low fluxes in electronics and living samples, a focusing heavy ion microbeam facility, for ions with energies of several MeV/u up to 100 MeV/u, was constructed in the Institute of Modern Physics of the Chinese Academy of Sciences. This facility has a vertical design and an experiment platform for both in-vacuum analysis and in-air irradiatio...

The use of microbeam techniques in radiobiology dates back to the 1920’s with the work of Tschachotin who irradiated the spawn of sea urchins and frogs with X-ray and ultraviolet light. In 1953, Zirkle and Bloom designed and constructed a microbeam facility [1] that utilized a 2 MeV proton beam of 2.5 m in diameter. Their facility, however, did not allow counting the radiation particles that en...

This chapter reviews the optics of pulsed laser microbeams and the use of basic instrumentation to provide pulsed laser microbeam capabilities within a microscope platform. Moreover, we review the principal mechanisms by which laser microbeams produce microsurgical effects in cellular targets. We discuss the principal photothermal, photomechanical, and photochemical damage mechanisms as well as...

The stand-alone microbeam, under development at RARAF, presents a novel approach to biological microbeam irradiation studies. Foregoing a conventional accelerator as a source of energetic ions, we propose to use a small, high-specific-activity, alpha emitter. Alpha particles emitted from this source are focused using a compound magnetic lens consisting of 24 permanent magnets arranged in two qu...

The tumoricidal mechanisms of microbeam radiation therapy, and the more recently proposed minibeam radiation therapy, for the treatment of brain tumors are as yet unclear. Moreover, from among the various parameters of beam geometry the impact of changing the beam width is unknown. In this study, suppression of tumor growth in human glioma cells implanted in mice was evaluated experimentally us...

BACKGROUND Nonablative fractionated laser resurfacing improves the texture of treated skin, but little is known about the molecular mechanisms that underlie clinical improvements. OBJECTIVES We sought to examine and quantify the time course and magnitude of dermal matrix changes that occur in response to nonablative fractionated laser resurfacing, with the dual goals of better understanding t...