Pulse fusion

ABSTRACT A brief history of the behavior of materials in nonuniform electrical fields is presented, followed by a theory of dielectrophoretic force and the derivation of the general force equation. Attention is paid to the several classes of polarization which lead to the experimental considerations of induced cellular dielectrophoresis. A distinction between batch and continuous methods is discussed, with a focus on a new microtechnique. While dielectrophoresis can induce aggregation of materials, i.e., cells, other orientational applications exist. Cell division, cellular spin resonance, and pulse-fusion of cells form topics appropriate to the realm of high-frequency electrical oscillations and are discussed in the context of living material. 

Electrical pulse-fusion can be done with a wide variety of cells, including bacterial, yeast, and higher plant cell protoplasts, as well as on erythrocytes and other mammalian cells. Because of the great potential of this technique it deserves close attention. The DEP-t-pulse-fusion technique has been used to meld mesophyll cell protoplasts of Avena saliva (oat), of Petunia inflata, and Vida faba (broad bean). The fused protoplasts proved to be viable as judged by vital stain (trypan blue), and could be developed into ex-plants in the case of Petunia i. 

The course in 1974 was Pulsed Fusion Reactors and opened with a wide ranging and stimulating talk by Dr R S Pease. A worthy quotation ... 

The plasma source implantation system does not use the extraction and acceleration scheme found in traditional mass-analy2ing implanters, but rather the sample to be implanted is placed inside a plasma (Fig. 4). This ion implantation scheme evolved from work on controlled fusion devices. The sample is repetitively pulsed at high negative voltages (around 100 kV) to envelope the surface with a flux of energetic plasma ions. Because the plasma surrounds the sample, and because the ions are accelerated normal to the sample surface, plasma-source implantation occurs over the entire surface, thereby eliminating the need to manipulate nonplanar samples in front of the ion beam. In this article, ion implantation systems that implant all surfaces simultaneously are referred to as omnidirectional systems. 

The small (<1 cm) sizes and brief (<1 //s) lifetimes of the fusion research plasmas preclude the use of most probe techniques. Laser pulse imaging... 

Pulsed plasmas containing hydrogen isotopes can produce bursts of alpha particles and neutrons as a consequence of nuclear reactions. The neutrons are useful for radiation-effects testing and for other materials research. A dense plasma focus filled with deuterium at low pressure has produced 10 neutrons in a single pulse (76) (see Deuterium AND TRITIUM). Intense neutron fluxes also are expected from thermonuclear fusion research devices employing either magnetic or inertial confinement. 

An important point is that these advances have been complemented by the concomitant development of innovative pulse-characterisation procedures such that all the features of femtosecond optical pulses - their energy, shape, duration and phase - can be subject to quantitative in situ scrutiny during the course of experiments. Taken together, these resources enable femtosecond lasers to be applied to a whole range of ultrafast processes, from the various stages of plasma formation and nuclear fusion, through molecular fragmentation and collision processes to the crucial, individual events of photosynthesis. 

Pulse-Chase Experiment for the Analysis of Protein Stability in Cultured Mammalian Cells by Covalent Fluorescent Labeling of Fusion Proteins... 

Pulse-Chase Experiments of Halo-Tag-Fusion Proteins... 

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