Fibril arrays

C. W. Wang, Z. Wang, M. K. Li, and H. L. Li, Well-aligned polyaniUne nano-fibril array membrane and its field emission property, Chem. Phys. Lett, 341,431-434 (2001). 

Figure 12 Four of the most common collagen fibril array patterns of organization (based on Weiner, S. Wagner, H. D. Annu. Rev. Mater. Sci. 1998,28, 271-298 and modified) (a) array of parallel fibrils, (b) woven fiber structure, (c) plywood-like structure, and (d) radial fibril arrays.

Certain combinations of fibril array organizations result in specific stmctures, like the formation of lamellar bone into secondary osteons, as described in Section 9.03.3.5.2. 

Collagen types I, II, and III form strong, organized fibrils, consisting of staggered arrays of tropocollagen molecules (Figure 6.19). The periodic... 

In this instance, adamantane was present to promote interaction of peptides through its hydrophobicity, but its attachment did not hinder fibril formation. It might be possible to chemically or biologically derivatise this group before being introduced to the peptide, or to select another hydrophobic component that could be suitably modified and attached to the peptide. This research also highlights the feasibility of creating peptide arrays comprised of several different sequences. 

Lamm MS, Sharma N, Rajagopal K et al (2008) Laterally spaced linear nanoparticle arrays templated by laminated beta-sheet fibrils. Adv Mater 20 447M 51... 

Within the scope of thermoelectric nanostructures, Sima et al. [161] prepared nanorod (fibril) and microtube (tubule) arrays of PbSei. , Tej by potentiostatic electrodeposition from nitric acid solutions of Pb(N03)2, H2Se03, and Te02, using a 30 fim thick polycarbonate track-etch membrane, with pores 100-2,000 nm in diameter, as template (Cu supported). After electrodeposition the polymer membrane was dissolved in CH2CI2. Solid rods were obtained in membranes with small pores, and hollow tubes in those with large pores. The formation of microtubes rather than nanorods in the larger pores was attributed to the higher deposition current. 

The polymer fibre is considered to be composed of a parallel array of identical fibrils. A single fibril is a series arrangement of domains with a varying angle to the fibre axis described by the orientation function p(Q) in the unloaded state. The strength of a domain is supposed to be given by... 

While a polar-zipper model was initially proposed for Asp2Glni3Lys2 (Perutz et ah, 1994), more recently a water-filled nanotube was proposed in which the homopolymer in the / -conformation forms a helical array having 20 residues per turn (Perutz et ah, 2002a,b). (In the earlier work, the diffraction pattern had been interpreted as a fiber pattern—that is, with the 4.8-A reflection in the fibril direction.) Rather than being attributed to intersheet stacking, the 8.4-A reflection was not accounted for. Further,... 

In many of the chloroplasts exhibiting incipient changes, clusters of ordered arrays of fibrils and crystalline bodies were observed in the stroma (Fig. 2, 3F). These fibrils and crystalloids were frequently associated with the chloroplast envelope and were often observed in conjunction with regions where small but noticeable alterations of the ultrastructure of the envelope were apparent. These alterations consisted primarily of an increase in the staining density of the envelope membranes (Fig. 2, arrows) and a frequent accumulation of electron-dense material between the two membranes of the envelope (Fig. 3, arrows). Larger deposits of electron-dense material also occurred in association with the membranes in these areas. Another unusual observation was the frequent presence of what appears to be a complex of several membranes including the chloroplast envelope membranes associated with the indentation of the chloroplast surface (Fig. 1, arrows) and the crystalloids in the stroma (Fig. 3F). 

Fu X, Wang Y, Huang L, Sha Y, Gui L, Lai L, Tang Y. Assemblies of metal nanoparticles and self-assembled peptide fibrils—formation of double helical and single-chain arrays of metal nanoparticles. Adv Mater 2003 15 902-906. 

Significantly, the ordered pattern of fibril deposition in the secondary wall of Micrasterias367 was shown to be derived from the structure of the complexes located in the plasma membrane. The results indicated that the widest fibrils, those in the center of a band, are formed by the longest rows of rosettes, those in the center of arosette array. The shorter rows of rosettes within an array give rise to narrower fibrils. This proportionality between the width of a secondary cellulose fibril and the number of rosettes involved in its formation provides strong evidence that the rosette structure plays a significant role in the synthesis of cellulose fibrils. 

The bacterial cellulose synthase from Acetobacter xylinum can be solubilized with detergents, and the resulting enzyme generates characteristic 1.7 ran cellulose fibrils (Fig. 20-4) from UDP-glucose.125/127-129 These are similar, but not identical, to the fibrils of cellulose I produced by intact bacteria.125 130 Each native fibril appears as a left-handed helix which may contain about nine parallel chains in a crystalline array. Three of these helices appear to coil together (Fig. 20-4) to form a larger 3.7-nm left-handed helical fibril. Similar fibrils are formed by plants. In both... 

Marrouche Np et al, Phased-array intracardiac echocardiography monitoring during pulmonary vein isolation in patients with atrial fibrillation impact on outcome and complications. Circulation 2003 107(21 ) 2710-271 6. 

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