White-Taylor cell

Other dichroic display types to improve the viewing angle of standard TN-cells can be found in the literature. The most popular are dichroic phase change effect displays or White-Taylor mode displays [21 ] and Heil-meier type dichroic LCDs [20, 22, 23]. 

Figure 38. Schematic operation of the White-Taylor dye guest-host chiral nematic electrooptic cell. In (a) for zero applied field the axis of each focal-conic domain is random in the x, y plane, as therefore is the dye, using homeotropic surface alignment. In (b) the texture is planar for the zero field state and therefore the dye spirals around the z direction. In (c) the focal conic (a) or planar (b) transition to homeotropic nematic has taken place above the threshold voltage V,], (WT). The black ellipses represent the dyes in the chiral nematic matrix.

Fig. 9.4 Osteoblast secretion and matrix vesicle formation. The outer surface of all bones is covered by fibroblast-like cells that differentiate into pre-osteoblasts that secrete osteoid matrix to remodel the surface as necessary. The surface osteoblasts extend into the osteoid tissue by long processes that attach to osteocytes (fully differentiated, nondividing osteoblasts) within the bone. Changes in the environment may be sensed by the osteocytes, which transmit them as remodeling signals to the osteoblasts. The osteoid matrix is filled with many small membrane-covered matrix vesicles containing various amounts of precipitated basic calcium phosphate (white circles) (Modified from Fig. 22-52 in The Molecular Biology of the Cell. B. Alberts et al., 4th Ed. 2002. Garland Science, Taylor Francis Group, New York)...

FIGURE 32.16 Physical compartmentalization. (a) 3D schematic representation and 2D cross section of the device shows how neurons loaded in the somal side of the device (black) are unable to cross through the narrow constriction, unlike their axons, which can extend into the axonal side (white), (b) Texas red dextran injected in the axonal side (right) does not cross into the somal side showing fluidic isolation between the compartments, (c) When green cell tracker dye is loaded into the axonal side it retrograde labels the axons and somas of the neurons. (Adapted from Taylor, A. M., et al., Nat Methods, 2, 8, 599. Copyright 2005. With permission from Macmillan Publishers Ltd.)... 

White and Taylor have described a new device that combines both the guest-host effect and the cholesteric-to-nematic transition. The pleochroic dye is added to a cholesteric material and the cell transmission changes when the cholesteric undergoes the cholesteric-to-nematic transition. Because of the rotational symmetry of the long axes of the dye molecules about the cholesteric helical axes, contrast ratios of greater than 4 to 1 were obtained without the use of a polarizer. 

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