Silver stain properties

Studies of the antimicrobial and therapeutic properties of silver and its derivatives have yielded an extensive scientific literature, ranging from clinically- to biochemically-based papers. The latter area includes studies in enzymatic and other macromolecular interactions to silver resistance encompassing plasmid-mediated patterns. The reduction to one silver compound (AgSD) in the current British National Formulary and to two compounds (AgSD and silver nitrate ophthalmic solution) in USP XXII may not be a true reflection of the use of silver in health care today. Silver compounds also find use in non-clinical situations, for example, as water disinfectants and, not considered in this review, as silver staining techniques for microscopy. 

Mucous cells, found in the neck of the gland, secrete a mucus with staining properties different from those of the surface epithelium. Argentaffin cells are not seen with ordinary staining or fixation techniques. After fixation with potassium bichromate and silver or chromium impregnation, they stand out as cells scattered singly between the lining of chief cells and the basal membrane. 

Detection.—Many of the reactions described under the properties of ozone can be used for the detection of this gas in the air. Exposure to an ozone-laden atmosphere causes the formation of a film of oxide on the surface of a globule of clean mercury and so causes this to drag or tail when it moves.6 The formation of a stain of silver peroxide on a clean silver surface 7 supplies a very trustworthy test for ozone, but... 

To look at a microscopic section of the C.C. stained by any silver procedure is, in some way, similar to looking at a screen where many pictures are projected simultaneously. If we do not have the proper filters which allow us to see these pictures individually we reach the apparent paradox that, because of the excess of information present on the screen, we do not get the information contained in it. In this respect mathematical models and some special mathematical algorithms are, in a sense, one of the types of "filters" which can be used to obtain the information contained in one section of the C.C. stained according to the rapid Golgi procedure. This makes possible the study of some of the properties of the structure of the neuropil of the C.C., and how this structure is affected by some pathological conditions, such as hypothyroidism. 

The relaxation process significantly alters the stress/strain properties of the fiber and can be incorporated in the drying as a continuous stage, or can be carried out by a batch process where the fiber is subjected to a hot wet environment, normally under a slight pressure, in an autoclave, to elevate the boiling point. As the temperature approaches 150°C, water plasticizes the molecules and the internal cracks and fissures fuse together. Silver sulfide staining (Chapter 17) can be used to examine for cracks and fissures. 

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