Fraction studies

Recently, Icenogle and Klingensmith (IB) carried out a detailed fractionation study of three polybutylene samples. 

Paralleling the work at CCDC were the critical solvent deashing and fractionation studies done on a continuous bench-scale unit at Kerr-McGee Technical Center, Oklahoma City, Oklahoma, Figure 3. The Kerr-McGee Critical Solvent Deashing and Fractionation Process has been previously discussed (3). 

Mullen et al. (1989) reported that Bacillus cereus, B. subtilis, E. coli and P. aeruginosa were able to sorb an average of 89% of the total Ag+ and 12-27% of the total Cd2+, Cu2+ and La3+ from a ImM solution. Using polyacrylamide-entrapped cells of Brevibacterium sp strain PBZ, Simine et al. (1998) measured a sorption capacity of 40 mg g-1 and 13 mg g-1 dry biomass for Pb and Cd, respectively. Hall et al. (2001) isolated two bacterial strains of P. syringae that were tolerant to 1000 mg L-1 Cu. Similarly, Amoroso et al. (2001) were able to obtain Streptomyces spp. strains R22 and R25 with a high tolerance to Cr from sediments of the Sail River, Argentina. The cells of R22 and R25 could accumulate 10.0 and 5.6 mg Cr g-1 dry weight, respectively, from a concentration of 50 mg Cr mL 1. Cell fractionation studies with strain R22 showed that most of the chromium... 

Histamine synthesis in the brain is controlled by the availability of L-histidine and the activity of histidine decarboxylase. Although histamine is present in plasma, it does not penetrate the blood-brain barrier, such that histamine concentrations in the brain must be maintained by synthesis. With a value of 0.1 mmol/1 for L-histidine under physiological conditions, HDC is not saturated by histidine concentrations in the brain, an observation that explains the effectiveness of large systemic doses of this amino acid in raising the concentrations of histamine in the brain. The essential amino acid L-histidine is transported into the brain by a saturable, energy-dependent mechanism [5]. Subcellular fractionation studies show HDC to be localized in cytoplasmic fractions of isolated nerve terminals, i.e. synaptosomes. 

Considerable evidence suggests that the major site of calcium sequestration and the source of intracellular calcium for signaling is the ER. In addition to the points already made, subcellular fractionation studies have demonstrated positive correlations of ATP-dependent Ca2+ accumulation and of IP3-mediated Ca2+ release with classical enzymatic markers for ER. Calcium uptake into the IP3-sensitive store is augmented by oxalate this augmentation is a property generally associated with the ER. 

Understanding of the intracellular localization of steroid receptors has gone through a number of phases, beginning with the view that receptors translocated from cytoplasm to nucleus in the presence of hormone. Indeed, with the exception of thyroid hormone receptors, which are exclusively nuclear in location, cell fractionation studies have revealed that in the absence of hormone, steroid receptors are extracted in the soluble or cytosolic fraction. However, when steroid is present in the cell, many occupied receptors are retained by purified cell nuclei. Histological procedures, such as immunocytochemistry, have confirmed the largely nuclear localization of occupied receptors, but... 

Taylor, R. E., Slota, P., Fraction Studies on Marine Shell and Bone Samples for Radiocarbon Analyses, In Radiocarbon Dating, pp. 422-432, Berkeley University of California Press, 1979. 

The development of modem methods, suitable for the analysis of ampholytes in biological fluids, provided means for isolating from urine some chemically better defined fractions containing peptide compounds. The methods used did not, however, exclude the existence of some other forms of combined amino acids in the fractions studied. 

Gleyzes C, Tellier S, Astruc M. Fractionation studies of trace elements in contaminated soils and sediments a review of sequential extraction procedures. TrAC Trend Anal. Chem. 2002 21 451—467. 

The present research was conducted to evaluate selected physicochemical properties of the dry roasted and air-classified navy, pinto, and black bean flour fractions. Studies were conducted to determine the chemical composition and to characterize the functional properties of dry-roasted bean flour fractions and to evaluate the suitability of the flours for use in foods systems. 

Experiments using fluorescein-labelled fMet-Leu-Phe indicate that the majority of re-expressed receptors that appear on the plasma membrane within 4-10 min after stimulation arise from the mobilisation of internal pools. Subcellular fractionation studies indicate that the pools of these receptors are the membranes of specific granules, although it is possible that these are on other membranes (e.g. on gelatinase-containing granules or se-... 

O Neil JR, Truesdell AH (1991) Oxygen isotope fractionation studies of solute-water interactions. In Stable Isotope Geochemistry A Tribute to Samuel Epstein. Taylor Jr. HP, O Neil JR, Kaplan IR (eds), Geochem Soc Spec Pub 3 17-25... 

Harrison AG, Thode HG (1958) Mechanism of the bacterial reduction of sulphate from isotope fractionation studies. Trans Faraday Soc. 54 84-96... 

Table II. Chemical Reactions Occurring during Irradiation Crosslinking and Scission (Soluble Fraction-Gel Fraction Study)...

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