Fracturing techniques

With the freeze-fracture technique, the fracture plane passes through liposomes which are randomly positioned in the frozen sample. Some liposomes will be cut far from their midplane sections, others through their midplane section. Therefore, the analysis of freeze-fracture pictures requires corrections for nonequatorial fracture. Besides, corrections have to be made for the size-dependent probability of a vesicle being in the fracture plane (Jousma et al., 1987 Guiot et al., 1980). Recently, results with a new technique based on electron microscopy was discussed this technique allows analysis not only of liposome size, but also of the number of bilayers (Lauten-schlager et al., 1988). 

M. J. Hrachovy. Hydraulic fracturing technique employing in situ precipitation. Patent WO 9406998, 1994. 

M Hirsch, G Renard, JP Faure, Y Pouliquen. (1977). Study of the ultrastructure of the rabbit corneal endothelium by the freeze-fracture technique Apical and lateral junctions. Exp Eye Res 25 277-288. 

Matthews, T.M. "Field Use of Superfrac - A New Hydraulic Fracturing Technique," SPE paper 2625, 1969 SPE Annual Meeting of AIME, Denver, September 28-October 1. 

Misak, M.D., Atteberry, R.D., Venditto, J.J. and Fredrickson, S.E. "A Fracturing Technique to Minimize Water Production," SPE paper 7563, 1978 Annual Fall Technical Conference and Exhibition of the SPE of AIME, Houston, October 1-3. 

Hannah, R.R. "Hew Fracturing Technique Leads to Improved Performance in the Mississippian Trend," J. Pet. Technol.(August 1976) 859 864. 

The process of infection of lupine nodule cells by Rhizobia was examined by the thin-section electron microscopic technique, as well as the freeze-fracture technique. Different membranes such as infection thread membranes, peribacterioid membranes, plasma membranes, membranes of cytoplasmic vesicles, and membranes of the Golgi bodies and ER were stained with uranium-lead, silver, phosphotungstic acid, and ZIO (31). ZIO stained the membranes of the proximal face of the Golgi bodies and endoplasmic reticulum. ZIO staining has given good contrast in thick sections such as a cotyledon cell, a root cell, and an aleurone layer for ER, dictyosomes cisternae, mitochondria, and nuclear envelopes (17,32-37). 

Though cellulose is one of the most important biopolymers, it has not yet been possible to completely elucidate its biosynthetic pathway, or establish exactly the cell organellae involved in its synthesis. However, during the last decade, the freeze fracture technique has been applied to investigate cell wall formation, and this has produced much information on the site where cellulose synthesis occurs. It is now generally accepted that both terminal and rosette complexes are responsible for cellulose synthesis (21). Our results (19,22) support that view. In a TEM-autoradiographic investiga-... 

Using the freeze fracture technique, electron microscopy and laser scanning confocal microscopy, it became obvious that these gap junctional channels are arranged as a cluster of channels with about 50 channels within one disk as stated by Gourdie et al. [1990]. 

To improve interwell communication further, a hydraulic fracturing treatment was performed at a depth of 79 to 84 ft in well 5 to ensure the displacement and detonation of the 300-qt charge of NG1. The effectiveness of the three fracturing techniques was determined by measuring airflow rates between selected wells before and after each test. 

Although the nature and extent of fractures created in the oil shale by the various fracturing techniques are not completely known, some... 

Integral proteins are usually free to move in the plane of the bilayer by lateral and rotational movement, but are not able to flip from one side of the membrane to the other (transverse movement). Immunofluorescence microscopy may be used to follow the movement of two proteins from different cells following fusion of the cells to form a hybrid heterokaryon. Immediately after fusion the two integral proteins are found segregated at either end of the heterokaryon but with time diffuse to all areas of the cell surface. The distribution of integral proteins within the membrane can be studied by electron microscopy using the freeze-fracture technique in which membranes are fractured along the interface between the inner and outer leaflets. 

The distribution of proteins in membranes can be revealed by electron microscopy using the freeze-fracture technique (Fig. 3b). In this technique, a membrane specimen is rapidly frozen to the temperature of liquid nitrogen (-196°C) and then fractured by a sharp blow. The bilayer often splits into mono-layers, revealing the interior. The exposed surface is then coated with a film of carbon and shadowed with platinum in order for the surface to be viewed in the electron microscope (see Topic A3). The fractured surface of the membrane is revealed to have numerous randomly distributed protuberances that correspond to integral membrane proteins. 

Parenchymal dissection Instead of the parenchymal-fracture technique used in the past, ultrasound dissection or aqua-jet dissection is now applied. 

Wei, R. P., and Alavi, A., In Situ Fracture Techniques for Studying Transient Reactions With Bare Steel Surfaces, J. of the Electrochem. Soc., 138,10 (1991), 2907-2912. 

---