Structured light imaging

Kim Ki H, So P T C, Kochevar I E, Masters B R and Gratton E 1998 Two-photon fluorescence and confocal reflected light imaging of thick tissue structures Proc. SPIE 3260 46-57... 

A further complication is that for a carbon, which has four different groups attached to it in a tetrahedral arrangement, there are two optical isomers called laevo (l-) and dextro (d-) from their different abilities to rotate the plane of polarised light. They are structural mirror images which cannot be superimposed ... 

Figure 30-17 (A) Two-dimensional map of the 260-kDa a subunit of the voltage-gated Na+ channel from the electric eel Electrophorus e/ecfns.438 441 (B) Image of the sodium channel protein obtained by cryo-electron microscopy and image analysis at 1.9 nm resolution. In this side view the protein appears to be bell-shaped with a height of 13.5 nm, a square bottom (cytoplasmic surface) 10 nm on a side, and a hemispherical top with a diameter of 6.5 nm. (C) Bottom view of the protein. (D) Axial section which cuts the bottom, as viewed in (C), approximately along a diagonal. From Sato et al.438 Notice the cavities (dark) and domain structures (light). The black arrow marks a constriction between upper (extracelllar) and lower (cytoplasmic) cavities. White lines indicate approximate position of the lipid bilayer. From Sato et al.i38 Courtesy of Chikara Sato.

X-ray microscopy n. This instrument and technique is similar to an optical microscope except that X-rays are utilized to magnify and study an object instead of visual light. Images beneath a surface can be studied because X-rays penetrate materials including metals. Defects located within the interior of an object (plastic pipe) can be observed without disturbing the structure or cutting a cross-section. The technique is useful for studying the... 

Oscilloscope traces from a line scan across the dark field reflecting light images were used to determine the amount of dispersion in a quantitative manner. However, this technique is not capable of evaluating details of the structure of the dispersed phase. 

Dal MM, Difeto F, Beltramo R et al (2010) Simultaneous two-photon imaging and photo-stimulation with structured light illumination. Opt Express 18 18720-18731... 

When the same structure is imaged by 400 nm, 10 fs laser pulses incident at 65° from the surface normal (Figure 8.3(b)) the contrast is dramatically different. The TR-PEEM image is now dominated by emission from hot spots randomly distributed on the mesa structures. These hot spots correspond to localized SP modes, which are resonant or nearly resonant with the excitation light. The trapping of light in nanometre seale asperities enhances the loeal... 

Irregularities in the fibrous structure, e.g. fibre bundles, were detected by using x-ray and transmitUng-light images of the specimens. These irregularities were analyzed by cross sectional SEM image analysis to determine whether the fibres are completely wetted or not. 

Oriented or crystalline structures such as transcrystalline layers can easily be seen in crossed polars. Many other examples of polarized light images of polymers are shown in Chapter 5 of Sawyer et al When counting randomly oriented birefringent particles such as polymer wear particles in tissue, some would be in their extinction orientation and not be visible under crossed polars. The solution is to use crossed circular polars. A quarter-wave plate, that is, one with a retardation of 2/4, placed after the linear polarizer and set at +45 °... 

A molecule is chiral if it cannot be superimposed on its mirror image (or if it does not possess an alternating axis of symmetry) and would exhibit optical activity, i.e. lead to the rotation of the plane of polarization of polarized light. Lactic acid, which has the structure (2 mirror images) shown exhibits molecular chirality. In this the central carbon atom is said to be chiral but strictly it is the environment which is chiral. 

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