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Fluorescence is a very powerful tool for work at the frontier of cell biology, photobiology and bioinstrumentation. The stated aim of the workshop was to highlight the significance of fluorescence work for the understanding of cell and tissue physiology, physiopathology and pharmacology, particulary in terms of the analytical use of fluorescent probes in oncology. In the organization of the workshop a multidisciplinary approach was selected. The purpose of the Advanced Research Workshop (ARW) was to bring together researchers in the various disciplines of tissue optics, imaging, microspectrofluorometry and state of the art probes, in order to explore the full benefits that can be derived in biomedicine through the convergence of these approaches. When applied to in vivo and in situ studies, fluorescence and related optical methods enable us to explore within tissues, cells and organelles photon effects previously understood only in solution photochemistry. Processes which can be studied at the molecular level by photophysics, photochemistry and physical chemistry can be evaluated in living tissue by fluorescence spectroscopy and imaging at the intracellular level in terms of structure and function. Thus, fluorescence adds a new dimension to cell biology and physiology. This approach is now supported by a full and versatile, rapidly growing armamentarium of new selective probes for organelles, enzymes, cations, cytoskeleton and metabolic control.
Over the last several decades, the number of people who are actively involved in the hobby or science of mineral collecting has grown at an increasing pace. In response to the growing demand for informa- tion which this large and active group has created, a number of books have been published dealing with mineralogy. As a result, the reader now has a choice among mineral locality guides, field handbooks, photo collections, or books dedicated to the systematic description of minerals. However, as interest in mineralogy has grown, as collectors have become increasingly knowledgeable and aware of mineralogy in its many facets, the need for more specialized information has also grown. Nowhere is this need greater than in the subject of the fluorescence of minerals. The number of collectors who now main- tain a fluorescent collection is substantial, interest is constantly increasing, and manufacturers have recently responded by the intro- duction of new ultraviolet equipment with major improvements in utility and performance. Yet when the collector searches for any information on this subject, little will be found. He or she will seek in vain for the answers to questions which present themselves as in- terest in fluorescent minerals grows and matures. Which minerals fluoresce? Where are fluorescent minerals found? What makes a mineral fluoresce? Why does ultraviolet light produce fluorescence? What is an activator, and how does it contribute to fluorescence? On these matters, the available mineralogy books are largely silent.
Fluorescence microscopy images can be easily integrated into current video and computer image processing systems. People like visual observation; they like to watch a television or computer screen, and fluorescence techniques are thus becoming more and more popular. Since true in vivo experiments are simple to perform, samples can be directly seen and there is always the possibility of manipulating the samples during the experiments; it is an ideal technique for biology and medicine. Images are obtained by a classical (now called wide-field) fluorescence microscope, a confocal scanning microscope, upright or inverted, with epifluorescence or transmission. Computerized image processing may improve definition, and remove glare and scattered light signal. It also makes it possible to compute ratio images (ratio imaging both in excitation and in emission) or lifetime imaging. Image analysis programs may supply a great deal of additional data of various types, starting with calculations of the number of fluorescent objects, their shapes, brightness, etc. Fluorescence microscopy data may be complemented by classical measurement in the cuvette yr by flow cytometry.
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