Electron micrographs of fibers

Fig. 4. Dark field electron micrograph of fibers and wide bundles (at B and C) that were anealed Ih at 383 K after drawing ( bamboo-structure ). The fibers consist of crystalline regions (bright areas) extended over the entire fiber cross section (Courtesy J. Petermann, Saarbrucken)...

Fig. 10. Scanning electron micrographs of fibers taken from fabrics given canbination polynerization-crosslinking treatments with a polynerization step of 16 h (WFC-16), 24 h (WFC-24), and 48 h (WFC-24) (49).

Textile Microscopy in Germany, Report No. 13 in the Quartermaster Textile Series (71), provides a valuable set of reference photomicrographs from Germany plus some electron micrographs of fibers, illustrative of techniques employed in the United States and Holland. 

Fibers of the control and selected chemically modified cottons were examined techniques of optical microscopy described previously.Ultra thin cross sections of the fibers were subjected to layer expansion by polymerization of methyl methacrylate and to solubility tests in 0.5 M cupriethylenediamine (cuene) and were examined by the techniques of transmission electron microscopy as previously reported.Scanning electron micrographs of fibers of selected samples before and after subjection to various solvents were also obtained. 

Fig. 8. Electron micrograph of Merino wool fibers in a fabric that have been treated with a typical shrink-resistance polymer, showing fiber—fiber bond...

Fig. 2. Electron micrographs of asbestos fibers (a) cbrysotile (b) crocidolite.

Fig. 5. Scanning electron micrographs of hoUow fiber dialysis membranes. Membranes in left panels are prepared from regenerated cellulose (Cuprophan) and those on the right from a copolymer of polyacrylonitrile. The ceUulosic materials are hydrogels and the synthetic thermoplastic forms a microreticulated open cell foam with a tight skin on the inner wall. Pictures at top are membrane cross sections those below are of the wall region. Dimensions as indicated.

Figure 3.14 Sickle-cell hemoglobin molecules polymerize due to the hydrophobic patch introduced by the mutation Glu 6 to Val in the P chain. The diagram (a) illustrates how this hydrophobic patch (green interacts with a hydrophobic pocket (red) in a second hemoglobin molecule, whose hydrophobic patch interacts with the pocket in a third molecule, and so on. Electron micrographs of sickle-cell hemoglobin fibers are shown in cross-section in (b) and along the fibers in (c). [(b) and (c) from J.T. Finch et al., Proc. Natl. Acad. Set. USA 70 718-722, 1973.)...

The two-phase morphologic structure has also been observed in the electron micrographs of polyethylene films and fibers obtained by orientational crystallization16 in which the amount of ECC was approximately 15 to 20% (the fraction of ECC in Porter s samples47 was 17 to 25%). 

Fig.1. Electron micrograph of a mast cell in human heart tissue. The cytoplasm contains numerous secretory granules. The mast cell is adjacent to a coronary blood vessel, surrounded by collagen fibers and close to a myocyte. Uranyl acetate and lead citrate stained. Orig. magnif. lO.OOOx. 

Figure 11.7 Scanning electron micrograph of pentacene fibers prepared by dewetting of a hot trichlorobenzene solution using the roller apparatus. The fibers are aligned along the rolling direction (reprinted with permission from Ref 71). The scale bar is 5 pm.

Fig. 10. Scanning electron micrograph of a fracture surface parallel to the direction of extrusion of an extrudate of a 45 55 PS-HDPE blend with a viscosity ratio p 1. Fibrous PS is shown at different stages of breakup the diameter of the largest fiber is about 1 pm (Meijer el til., 1988).

Muhlethaler, K. Electron Micrographs of Plant Fibers. Biochem. bio-physica Acta 3, 15 (1949). 

FIGURE 4-4 Electron micrograph of a single peripheral nerve fiber from rabbit. Note that the myelin sheath has a lamellated structure and is surrounded by Schwann cell cytoplasm. The outer mesaxon (arrowhead) can be seen in lower left. AX, axon. (Courtesy of Dr Cedric Raine.)... 

Figure 5.5 Computer-generated model of quadruple helix structures made of D-Glu-8 (1) based upon image-processed electron micrograph of helical fibers. Reprinted with permission from Ref. 35. Copyright 1993 by the American Chemical Society.

Figure 5.8 Electron micrographs of (a) right-handed helices and tubules from A-dodeca-5,7-diyne-D-galactonamide (10) and (b) braided fibers from A-dodeca-5,7-diyne-L-arabonamide (11). Reprinted with permission from Ref. 47. Copyright 1994 by the American Chemical Society.

The muscle fibrils are embedded in sarcoplasm, each individual fibril showing the banding pattern of the whole fiber (Bowman, 1840). Myosin could be extracted from muscle with strong salt solutions. From the altered appearance of the bands after extraction it was suggested that this protein was a major component of the A bands (Kuhne,1864 Danilewsky, 1881). The localization of myosin in the A bands and of actin in the I bands was convincingly shown by Jean Hanson and Hugh Huxley (1954-1955) in electron micrographs of transected fibers and confirmed after selective extraction to remove myosin (Hasselbach, 1953 Hanson and H.E. Huxley, 1953-1955). 

Fig. 8.1 Electron micrographs of different nanocarbon composite types (top) and their schematic representation (bottom). The nanocarbons can be dispersed as a filler (left), combined with macroscopic fibers in a hierarchical composite (middle), or assembled as a continuous nanostructured fiber (right). Micrographs from references [7, 8, 9], with kind permission from Elsevier (2010, 2008, 2009).

Fig. 8.9 Different methods for spinning CNT fibers and scanning electron micrographs of representative samples, (a) Wet spinning of nanocarbons dispersed in liquid, (b) drawing from a forest of aligned CNTs and (c) direct spinning from the gas phase during CNT synthesis by CVD. Images from references [53,59, 60, 61,62], With kind permission from AMS (2000, 2013), Elsevier (2007, 2011), Wiley (2010).

FlC. 3. Electron micrographs of assembled histone fibers (a) H4, acid-extracted (b) H3-H4, acid-extracted (c) H3-H4, salt-extracted (d) H2AH2BH3H4, acid-extracted (magnification x 78,000). 

Euchromatin generally corresponds to looped 30-nm fibers. Heterochromatin is more highly condensed. Figure 1-1-14 shows an electron micrograph of an interphase nucleus containing euchromatin, heterochromatin, and a nucleolus. The nudeolus is a nuclear region spedalized for ribosome assembly (discussed in Chapter 3). 

With the demise of the uniform fiber model in 1974, it became necessary to devise other models to account for the early electron micrographs of chromatin fibers and the X-ray diffraction studies (see Ref. [1], Chapter 1). Two models appeared in 1976, and were the major contenders for consideration in 1978. The superbead model of Franke et al. [36] envisioned the chromatin fiber as a compaction of multi-nucleosome superbeads . The solenoid model of Finch and Klug [37] postulated a regular helical array of nucleosomes, with approximately six nucleosomes per turn and a pitch of 10 nm. Although a number of competing helical models appeared in the 1980s (see Ref. [1], Chapter 7) the solenoid model remains a serious contender to this day. Structural details of this model, such as the precise disposition of linker DNA, are still lacking. 

Fig. 55a. In the presence of detergents, e.g. SDS, micellar fibers do not rearrange to crystals, because crystallization nuclei with head-to-tail sheets cannot be formed, b Electron micrograph of a 2-month-old gluconaniide D-28-8 gel, which was kept at 60 °C in the presence of SDS (molar ratio 10 1). Micelles and double helices occur (PTA 2% post-strained, bar = lOOnm). c Electron micrograph of a gel, which was kept at 20 °C and contained more SDS (molar ratio 2.5 1). Vesicles and multiple helices are apparent (PTA 2% poststained, bar — lOOnm) [377]...

Eig. 20. Scanning Electron Micrographs of the fracture surfaces of epoxy composites made with the same A carbon fiber with three different interphase conditions. Fracture is perpendicular to the... 

FIGURE 5-31 Structure of skeletal muscle, (a) Muscle fibers consist of single, elongated, multinucleated cells that arise from the fusion of many precursor cells. Within the fibers are many myofibrils (only six are shown here for simplicity) surrounded by the membranous sarcoplasmic reticulum. The organization of thick and thin filaments in the myofibril gives it a striated appearance. When muscle contracts, the I bands narrow and the Z disks come closer together, as seen in electron micrographs of (b) relaxed and (c) contracted muscle. 

Figure 17-26 Electron micrograph of the tip of a Nation-coated carbon fiber electrode. The carbon inside the electrode has a diameter of 10 ixm. Nafion permits cations to pass but excludes anions. /Photo courtesy R. M. WigMman. From R. M. Wightman. L. J. May, and A C. Michael. Detection of Dopamine Dynamics in the Brain, Anal. Chem. 1988, 60. 76VA ]...

Figure 2. The scanning electron micrographs of the as-prepared samples (a) without hydroxymenthyl fiber, (b) containing hydroxymenthyl fiber.

Figure 8-1 Electron micrograph of a thin section of a fat storage cell or adipocyte. L, the single large fat droplet N, nucleus M, mitochondria En, endothelium of a capillary containing an erythrocyte (E) CT, connective tissue ground substance which contains collagen fibers (Co) and fibroblasts (F). The basement membranes (BM) surrounding the endothelium and the fat cell are also marked. From Porter and Bonneville.6 Courtesy of Mary Bonneville.

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