Fiber Assemblies

Outer Fluid Inner Fluid Inner Needle 

The inset in each figure shows the cross-sectional structure of the spinneret system used for fabricating the nanofiber. (Zhao, Y., et. al.. Journal of American Chemical Society, 129, 764-765,2007.) 

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Fig. 1. A, hoUow-fiber spool B, hoUow-fiber cartridge employed ia hemodialysis C, cartridge identical to item B demonstrating high packing density D, hoUow-fiber assembly employed for tissue ceU growth E, hoUow-fiber bundle potted at its ends to be inserted into a cartridge or employed ia a situation...

The solution is dialyzed against the same buffer using a hollow fiber assembly, and then added onto a column of Affi-Gel Blue (50-100 mesh, 2 x 15 cm, Bio-Rad) prepared with the same buffer. The column is washed with the same buffer. Then luciferase is eluted with 50 mM Tris-HCl, pH 8.5, containing 5mM EDTA, 3 mM DTT, and 0.5 M NaCl (Hastings and Dunlap, 1986, state that it may be preferable to omit the Affi-Gel step because of difficulties encountered). 

Chromatin fiber assembly under applied force... 

Fig. 6. Schematic illustration of the stopped-flow magnetic tweezers experiments to follow single chromatin fiber assembly, (a) Flow diagram of how the experiment was performed, (b) A blow-up of the cuvette, with the bead attached to its side note that the DNA tether is not normal to the wall of the cuvette because of the position of the external magnet, i.e., the z direction is out of the plane of the video frame, (c) A schematic explaining the calculation of the distance traveled by the bead across the videoscreen. The X- and y-coordinates of the bead position on each successive video frame are used to calculate the projected traveled distance, (d) The actual shortening of the fiber can be calculated from the projected shortening (travel of bead across screen) and the cosine of the angle theta.

Earlier attempts to use the AFM for mechanically stretching chromatin fibers have run into a rather unexpected artifact. Long native chromatin fibers isolated from chicken erythrocytes, or fibers assembled in vitro from purified histones and relatively short, tandemly repeated DNA sequences were deposited on mica or glass surfaces and pulled with the AFM tip [69,70]. In such stretching experiments the scanning of the sample in the x- and y-direction used for imaging was disabled, and the cantilever-mounted tip was allowed to move only in the z-direction, i.e., upwards and downwards, away and towards the surface. When the AFM tip is pushed into the sample, it may attach to the sample by non-specific adsorption upon retraction it stretches the sample and force-extension curves are recorded (see Fig. lb for an explanation of a typical force curve). 

Three-dimensional textile preforms are continuous fiber assemblies which are fully integrated with multi-axial in-plane and though-the-lhickness fiber orientations. Ko (1989) and Chou (1992) presented comprehensive reviews on this topic, and a brief summary is given in this section. Composites containing three-dimensional textile preforms display many unique advantages which are absent in traditional two-dimensional laminate composites, and they include ... 

SPME holders with one of two fiber assemblies were used ... 

HSSPME Extraction Procedure. Manual SPME holders were used with a 100- am poly(dimethylsiloxane) (PDMS) and 65- am poly(dimethylsiloxane)-divinylbenzene (PDMS-DVB) fiber assembly (Supelco, Bellefonte, PA). The fibers were conditioned as recommended by the manufacturer. 

Figure 4.14 Schematic diagram of the melt infiltration process for flow past a unidirectional fiber assembly.

One lead- in was in contact with the primer plug, the other with the igniter retainer. The bridge and the fiber assembly were encased with a small quantity of LSt(Lead Styphnate) colored green with NC lacquer and around this was placed loose BkPdr chge... 

Lys and Glu residues at the e and g sites are blue and red, respectively the buried, offset Asn residues at a are green. Adapted from Pandya et al (2000). (B) Negative-stain transmission electron micrograph image for fibers assembled from the sticky ended building blocks. Adapted from MacPhee and Woolfson (2004). 

Brown-Augsburger, P. B., Broekelmann, T., Rosenbloom, J., and Mecham, R. P. (1996). Functional domains on elastin and MAGP involved in elastic fiber assembly. Biochem. J. 318, 149-155. 

Fig. 5. Retraction requires Yersinia phosphatase (YOP) plus an additional component in S-100. (A) Time-lapse sequence of phase contrast micrographs of a fiber assembled in S-100 and then perfused with S-100 containing YOP. The vesicle-bearing end of the fiber is at the top. With time, the fiber shortened and its optical density decreased. Numbers in each frame are elapsed time in minutes. (B) Fiber perfused with YOP in KPM assembly buffer. Without S-100 present, the fiber lost optical density but exhibited very litde shortening. (C) A similar sequence showing a fiber perfused with S-100 containing 1 mM ATP, but without added YOP. The fiber continued to grow at its vesicle bearing end and did not retract. Bars, 5 /im. Reproduced from Science, 2003, vol. 302, pp. 1405-1407.

Fig. 9 Cell-fiber sandwiches can be constructed by LbL cell/fiber assembly. The cells are sandwiched between layers of electrospun fiber mashes. The mesh thickness and cell loading can be controlled within this process. Reprinted, with permission, from [190] copyright (2009) Mary Ann...

Morkin, E. 1970. Postnatal muscle fiber assembly localization of newly synthesized myofibrillar proteins. Science 167 1499-1501. 

Baudet J, Rochet M, Salmon M, and Vogt B. Hollow fiber assembly for use in fluid treatment apparatus. US Patent 3,993,816, Nov 1976. 

The Rho family of small GTP-binding proteins functions to regulate the assembly of distinct actin structures in cells Rho regulates stress fiber assembly, Rac regulates lamellipodia protrusion and Cdc42 stimulates protrusion of the plasma membrane to form filopodia (Ridley and Hall, 1992 Ridley et at., 1992 Nobes and Hall, 1995 Kozma et at., 1995). All three regulate attachment of cells to the extracellular matrix via adhesive integrin structures (Nobes and Hall, 1995). 

Fig. 3. C3 transferase inhibits LPA-induced stress fiber assembly. C3 was injected into confluent serum-starved Swiss 3T3 cells at concentrations of 200(xg/ml (a, b), lOOng/ml (c, d) and 20(ig/ml (e, f). Cells were stimulated after 15min with LPA (lOOng/ml), fixed 30 min later and stained for filamentous octin with TRITC-conjugated pholloidin (a, c, e). FITC-conjugated dextran was co-injected with C3 transferase as a marker of injected cells (b, d, f). Note injection of C3 transferase at 200ng/ml caused rapid rounding and detachment of the cells, and stress fibre assembly was not completely inhibited in cells injected with 20ng/ml C3...

A hollow-fiber module consists of a large number of fibers assembled together in a module, as shown in Fig. 13. The free ends of the fibers are often potted with agents such as epoxy resins, polyurethanes, or silicon rubber. The membranes are... 

After sample sorption, the fused-silica fiber is withdrawn into the needle, and the needle is removed from the sample vial and introduced into the GC injector, where the sorbed analytes are thermally desorbed and analyzed. The fiber assembly is reusable. Extraction may be accomplished either by direct sampling in the water or by sampling the headspace above the sample. Because the SPME can attain detection limits of 15 ng/L for both volatile and nonvolatile compounds, the technique can be used for the U.S. Environmental Protection Agency (EPA) Methods and the Ontario Municipal/Industrial Strategy for Abatement (MISA) Program (Arthur et al., 1992). 

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