Fiber studies

Bouldin TW, Cavanagh JB. 1979a. Organophosphorus neuropathy. I. A teased-fiber study of the spatio-temporal spread of axonal degeneration. Am J Pathol 94 241-252. 

As noted above, disagreement has often been observed among different studies on the effects of fiber, phytic acid and protein source on mineral utilization. Some possible reasons include (a) estimates of absorption from single meals (with or without previous consumption of the same foods used in the test meal which may also affect results) may not always be equivalent to results from multi-day balance studies, (b) in balance studies, the failure to allow sufficient time (e.g., 1-2 weeks or more) for adaptation may alter the findings, (c) variations in the compositions of meals or diets, including mineral levels, between studies may influence the results obtained, and (d) the persons used as subjects vary and this may have an affect. In addition, in the fiber studies, the levels, types, and particle size of fiber fed have varied widely and levels of other possibly confounding components (e.g., caffeine, tanins, oxalates) may have differed. 

Because of the nonuniform nature of the fibers studied, this work was necessarily empirical in nature. Its main purpose is to illustrate the unique properties and property trends of these elastomeric composites in comparison with conventional rubber compounds. 

Film diffraction data can be obtained by several techniques flat plate camera, cylindrical camera or precession camera. We chose the latter, because it records a relatively undistorted "slice" of diffraction transform (reciprocal space) (19,20). We felt that this characteristic of the precession technique outweighed the disadvantages of longer exposure times (this was lessened by use of a Helium atmosphere in the camera enclosure). For potassium bromide amylose, the fiber studied, this required exposure of a 79y x 79y x 300y fiber specimen for 45 hours (35kv,... 

The fiber studied was kindly provided by Professor G. Berry of Carnegie-Mel Ion University. The authors thank Mr. S. Allen for furnishing the SEM picture of Figure 1. We also thank Dr. A. Kulshreshtha and Mr. W. Adams for helpful discussions throughout this work. Financial support was received from the U.S. Air Force through contract F33615-78-C-5175 and the Materials Research Laboratory of the University of Massachusetts. One of us (EJR) is indebted to the CNRS for favoring his stay at the University of Massachusetts. 

Bupivacaine is more cardiotoxic than other local anesthetics. This reflects the fact that bupivacaine block of sodium channels is potentiated by the long action potential duration of cardiac cells (as compared to nerve fibers). Studies have shown that the most common electrocardiographic finding in patients with bupivacaine intoxication is slow idioventricular rhythm with broad QRS complexes and eventually, electromechanical dissociation. 

The acrylic fibers studied are based on an acrylonitrile (94%), methacrylate (6%) copolymer with a diameter of 12-20 microns. The cell used for the measurement is illustrated in Fig. 7-7. Resolution was 3 cm-1, and 50-150 scans were taken. Figure 7-8 shows the Raman spectra of a blue dye fiber, red dye fiber and an undyed methacrylic fiber. The dye vibrations can be readily observed. Figure 7-9 shows the subtraction spectrum (blue dyed fiber minus the undyed fiber). The subtracted spectrum (a) is compared to a blue cobalt dye (b), and the agreement is excellent. 

TABLE 5 Surface Free Energy Components of High Strength Carbon Fibers Studied by Two-Liquid Tensiometric Method (in mJ/m2)... 

The adsorption energy level or potential of the molecules, f(s)=1/2, for all the carbon fibers studied in this work, is presented in Table 13, which can give an information on the eventual mobility of molecules at an interfaces. 

Comparison with Asbestos and Glass. Tables III, IV, V, and VI catalog the properties obtained when the two polystyrenes were reinforced with asbestos and glass. Table VII compares the reinforcing effects of the several fibers studied at 30 wt %. The data show that particular fibers improve particular properties. The tensile modulus and tensile strength are most improved by glass the heat deflection is most improved by asbestos, and the impact strength is most improved by polyester. 

Elastic Modulus. The third key issue relates to improvements required in the elastic modulus of these ceramic fibers. Studies indicate that modulus improvements will depend on careful control of composition and increases in fiber density (24). Earlier discussions in this chapter summarized the low densities of these ceramic fibers relative to their crystalline counterparts, as well as the existence of considerable pore volume. 

For fiber studies polyester BB1 was chosen. A method to measure birefringence developed by Yang and co-workers (18) was applied on polymer BB1 fibers and showed no dependence on DR, but remained constant 0.32 within experimental error. Similar observations were made by McIntyre and co-workers with a somewhat similar LC co-polyester with chloro instead of phenyl-hydroquinone and 25 mol% 4,4 -dicarboxydiphenylether (13). 

Other dietary interventions or diet supplements may be useful in certain patients with lipid disorders. Increased intake of soluble fiber in the form of oat bran, pectins, certain gums, and psyllium products can result in useful adj unctive reductions in total and LDL cholesterol, but these dietary alterations or supplements should not be substimted for more active forms of treatment. Total daily fiber intake should be about 20 to 30 g/day, with about 25%, or 6 g/day, being soluble fiber. Studies with psyllium seed in doses of 10 to 15 g/day show reductions in total and LDL cholesterol ranging from about 5% to 20% They have little or no effect on HDL cholesterol or triglyceride concentrations. These products also may be useful in managing constipation associated with the bile acid sequestrants. Psyllium binds cholesterol in the gut but also reduces hepatic production and clearance. Fish... 

The radiation modification of fibers by means of the SEM electron beam was studied in this paper. From the pictures captured, it is observed that the proper selection of SEM radiation wavelength and time can have significant effects on the appearance of fibers studied. The effect of time on this variation is summarized in Table 2. For the case of acrylic fiber it takes 640s to get to a maximum deflation whilst this time for viscose rayon is as short as 30s. 

Riiegg JC, Pfitzer G (1985) Modulation of calcium sensitivity in guinea pig -taenia coli skinned fiber studies. Experientia 41 997-1001 Riiegg JC, Pfitzer G (1991) Contractile protein interactions in smooth muscle. Blood Vessels 28 159-163... 

Expression of MHC Isoforms The expression of MHC isoforms in a muscle determines its functional properties. Single fiber studies have demonstrated an association between MHC isoform composition, force generation and... 

Acid hydrolysis of hitman fecal samples collected after Ingestion of different dietary fibers produced monosaccharides that were related to the fibers Ingested. Dietary fibers studied In five normal male subjects were cellulose, xylan, corn bran and pectin. Increases In monosaccharides In recovered hydrolyzed feces from fiber diets compared to those from the fiber-free diet were galactose for the pectin diet xylose and glucose for the cellulose diet xylose and mannose for the xylan diet and arablnose, xylose, galactose and glucose for the corn bran diet. Comparison of the fecal results to those for the Intact food fibers showed that fermentation of fiber components In the colon was different for each fiber. 

To further the understanding of lignin as a component of the dietary fiber, studies of three aspects of the properties of enzymatically isolated wood lignin are discussed here (1) the effect of cations and com-... 

S. Wang and H. J. Dudek, Structure of phases in the 8-AI2O3 fiber studied by convergent beam electron diffraction. Metal. Mater. Trans., 27A, 3318-3329 (1996). 

Table 9.6 gives the atomic percentages of the surface concentrations of elements determined on a range of carbon fibers studied using wide angle XPS spectrum. 

Sturm H, Schulz E, Atomic force microscopy with simultaneous ac conductivity contrast for the analysis of carbon fibre surfaces. Composites Part A—Appl Sci Manuf, 27(9), 677-684, 1996. Zhdan PA, Grey D, Castle JE, Surface structure of the PAN based carbon fibers studied by the scanning probe microscopy (SPM), 22(1-12), 290-295, 1994. 

The equilibrium between A-DNA and B-DNA is very strongly and subtly influenced by the environment. From the early fiber studies, where conformational transitions to A-DNA were seen at low relative humidity, the prevailing dogma emerged that it is changes in the water activity (specifically lowering the water activity) that lead to stabilization of A-DNA. Although the effective water concentration is clearly a factor in the stabilization of A-DNA, the effect is more... 

Patnaik S, Sarangi S, Mohanty AK, Singh BC (1989) Graft copolymerization of acrylonitrile onto jute fibers (Studies on Ce (IV)- hippuric acid redox system). J Appl Polym Sci 37 2099-2107... 

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