Fibrous extraction

Saito, Y., M. Imaizumi, K. Ban, A. Tahara, H. Wada, and K. Jinno. 2004. Development of miniaturized sample preparation with fibrous extraction media. J. Chromatogr. A 1025 27-32. 

The manuf of NC is similar in that it involves the same nitrating acids as used for TNT, but used to treat cotton linters or wood pulp (raw cellulose) in a series of vats and reactors similar to the ones used for TNT. The crude NC is similarly subjected to a series of w and aq soln washes until it is finally delivered as a purified, fibrous mat — ordinarily wet with w or ale for safety. Again, there are major wastewater streams laden with spent reagents and extracted impurities... 

Upon increase in salt concentration to 2 M, histone octamers were obtained (Thomas and Butler, 1978). The octamer could be assembled from acid-extracted as well as from salt-extracted histones (Thomas and Butler, 1978). In a concentrated solution of the four core histones (prepared by acid extraction) at an ionic strength higher than 2 M NaCl (minimum 10 mg/ml histone concentration), there is a small fraction of assembled fibrous structures which can be observed in the electron microscope (Sperling and Bustin, 1976 Wachtel and Sperling, 1979). These fibers (see Fig. 3d) are 60 A in diameter and have a 330 A axial repeat, and were shown to be composed of the four core histones in an equimolar ratio (Wachtel and Sperling, 1979). The percentage of fibers in the solution of the four core histones is promoted by increase in histone and salt concentrations. 

Fig. 1. (opposite page) Distribution of FITC-conjugated BSA in various fibroblast cell lines under different fixation/permeabilization regimes. (A-D) Protein distribution in living cells (A) PtKj, (B) CHO, (C) 3T3, and (D) HeLa cells. The protein is excluded from the nuclei of all cells. (E-H) Protein distribution in cells extracted for 10 min with 0.1% Triton X-100 before fixation for 30 min with 3.7% formaldehyde (E) PtKi, (F) CHO, (G) 3T3, and (H) HeLa cells. Nuclear fluorescence is seen in (E) PtKj and (G) 3T3 cells. (I-L) Protein distribution in cells extracted for 10 min with 1% Triton X-100 before fixation for 30 min with 3.7% formaldehyde (I) PtKj, (J) CHO, (K) 3T3, and (L) HeLa cells. No fluorescence is detected in the cells with the exception of some nuclear fluorescence seen in (L) HeLa cells. (M-P) Protein distribution in cells fixed for 30 min with 3.7% paraformaldehyde before permeabilization for 10 min with 0.1% Triton X-100. Fluorescence is seen primarily in the cytoplasm with the exception that nuclear fluorescence is seen in (M) PtKi and (N) CHO cells. (Q-T) Protein distributions in cells fixed for 5 min with 90% methanol, 50 vaM EGTA at -20°C (Q) PtKj, (R) CHO, (S) 3T3, and (T) HeLa cells. All cells show an overall low fluorescence, fibrous-textured cytoplasmic fluorescence, and bright staining at the periphery of the nucleus. 10 mm per scale division (black bar). (Reproduced with permission from ref. 6.)... 

The hydrodynamics are mainly influenced by the size and form of the particles and by the particle size distribution, which in most cases should be in a range between 0.4 and 0.8 mm. Too small particle sizes can cause channelling which, for example, can occur during the extraction of paprika powder, egg-yolk powder, cocoa powder, and algae powder. Fibrous feed materials such as ginger, black- and green-tea, and paprika have a tendency to swell and block the filters at the outlet of the extractor. The mechanism of transport in the solid phase proceeds in the following parallel and consecutive steps. 

While gravity-fed columns including adsorption or ion exchange are recommended when extensive sample cleanup is required, the analyst should be cautious about contamination and adsorptive effects contributing to sample loss. Liquid-liquid partitioning is the preferred technique. When concentrating solvents, care should be taken to insure against loss of volatile extracts. Plastic equipment or fibrous filters should be avoided. 

ASBESTOS. The tenn asbestos is a generic designation referring usually to six types of naturally occurring mineral fibers which are or have been commercially exploited, These fibers are extracted from certain varieties of hydrated alkaline silicate minerals comprising two families seipe.ntin.es and amphiboles. The serpentine group contains a single fibrous variety chrysotile five fibrous forms of amphiboles are known anthophyllite, amosite, crocidolite. tremolite, and actinolite... 

Folklore The name urtica is believed to be derived from the Latin verb urere , to bum, most probably referring to the stinging action of the plant. Nettle is a fibrous plant and was used in cloth manufacture from the Bronze Age until the early twentieth century. The fresh young plant tops have been cooked as a spinach-like vegetable dish, and used to be brewed into a nettle beer in certain parts of the United Kingdom. The herb was known as a blood purifier which, in current terms, is a detox herb. The herb has a high chlorophyll content and has been used as a source for extraction of this natural colour (Bown, 2003 British Herbal Medicine Association, 1983 Graenwald et al, 2002 Hutchens, 1973 Shealy, 1998 Tierra, 1998). 

Solubility of cellulose in the products has also been used to indicate the presence of covalent bonds between cellulose and the polyvinyl copolymer. Thin sections of fibrous cellulosic copolymers, as prepared for electron photomicrography, are examined both before and after successive extractions with solvents for cellulose and for the polymer. The presence of undissolved cellulose and polymer in the extracted thin section is interpreted as evidence for the presence of covalent bonds and for grafting (52). 

Highberger, J. H., Gross, J., and Schmitt, F. O. (1950). Electron microscope observations of certain fibrous structures obtained from connective tissue extracts. /. Am. Chem. Soc. 72, 3321-3322. 

Curare is the arrow poison of the South American Indians, and it may contain as many as 30 different plant ingredients, which may vary widely from tribe to tribe according to local custom. Curare is prepared in the rain forests of the Amazon and Orinoco, and represents the crude dried extract from the bark and stems of various plants. The young bark is scraped off, pounded, and the fibrous mass percolated with water in a leaf funnel. The liquor so obtained is then concentrated by evaporation over a fire. Further vegetable material may be added to make the preparation more glutinous so that it will stick to the arrows or darts. The product is dark brown or black, and tarlike. 

Improvement of fibre diffraction by chemical means was exampled by the results obtained with hydrolytic and other extractions of fungal tissue, in particular with reference to the (1-3)-/ -D-glucan component in the fibrous mycelial ropes (rhizomorphs) of Armillaria mellea. The rhizomorphs in the native state produce only one, oriented but diffuse and weak spacing attributable to (1-3)--D-glucan. After the adequate chemical extractions they yielded a complete fibre... 

Oil extraction produces an undecorticated (hulled) safflower meal with approximately 200-220g/kg CP and 400g/kg CF. The undecorticated meal is also called whole pressed seed meal, whereas the decorticated meal is referred to as safflower meal. Decortication of the hulled meal yields a high protein (420-450g/kg CP), less fibrous (150-160g/kg CF) meal, which is more suitable for inclusion in poultry or pig diets (Darroch, 1990). 

When crystallization is completed the fibrous phosphate can be extracted from the ultraphosphate matrix by leaching the system with hot water. 

Extractives sometimes prevent or inhibit the utilization of wood. For example, woods containing phenolic type extractives cannot be pulped via the sulfite process. The so-called "pitch troubles" in the pulp and paper industry result from the tendency of the resin type extractives to coagulate and adhere to metal and fibrous surfaces. Also the presence of extractives result in a higher consumption of pulping chemicals and in lower pulp yields. 

The most recent publication reviewed was by Einspahr and Harder (63), who discuss the basic properties of hardwood barks that could be important in the manufacture of any fibrous product. This was a progress report showing results for 16 pulpwood species work is in progress on 16 additional species. Measured were such bark factors as specific gravity, extractives content, strength, toughness, reaction to hammermilling, and ash content. 

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