Concentration, assessment

The values ( )o for the calibration standards are estimated by plotting log fe values as a function of organic modifier concentrations assessed from at least three iso-cratic experiments and obtained with [39] ... 

Chudy, M., Wroblewaski, W., Dybko, A., Brzozka, Z., PMMA/PDMS based microfluidic system with optical detection for total heavy metals concentration assessment. Micro Total Analysis Systems, Proceedings 5th pTAS Symposium, Monterey, CA, Oct. 21-25, 2001, 521-522. 

In many references that describe the relationship between the concentration of a contaminant in the pore water and the total concentration in soil, the kind of pore water concentration assessed (inclusive or exclusive of organic and inorganic metal complexes) is not mentioned. 

For the preparation of carbonyl-free solvents see Section 5.3.2.2.) The cells are washed three times in serum-free medium and harvested by scraping. The harvested cells are washed again with PBS, pH 7.4. Cell disruption is effected by light sonication and after centrifugation (600 x g, 15 min) the insoluble material is removed. The supernatant fraction is retained and the protein concentration assessed by the Lowry assay. 

GHb has been firmly established as an index of long-term blood glucose concentrations and as a measure of the risk for the development of complications in patients with diabetes mellitus. GHb was a cornerstone of the DCCT. (To prevent assay variability [see section on assay standardization later in this chapter], all GHb assays in the DCCT were done in a central laboratory that measured Hb Aj by HPLC.) The DCCT documented that there is a direct relationship between blood glucose concentrations (assessed by... 

Samples believed to be contaminated with copper sulphate from respirometer (EC50 values >90% exceed highest effluent concentration assessed in the 100% test). d Composite sample consisted of equal volumes of replicates 1 to 3. 

Ultraviolet Absorption The ultraviolet absorption characteristics of the aromatic side chains of the primary amino acid sequence are often used to estimate an extinction coefficient for a protein. The extinction coefficient is calculated based upon the number of tyrosine, tryptophan, and phenylalanine (aromatic) residues in the protein. Phenylalanine has a relatively weaker absorptivity and may not be included in the calculations. One advantage of this approach is the fact that it is relatively nondisruptive, leaving protein conformation undisturbed. In addition, the same solution used for the concentration assessment can be removed from the cuvette and used for additional experiments. The measurement is based upon Beer s law ... 

Dal belo, S. E., Rigo Caspar, L., Campos, B. G. M. and Maria, P. 2006. Moisturizing effect of cosmetic formulations containing Aloe vera extract in different concentrations assessed by skin bioengineering techniques. Skin Research and Technology, 12 (4), pp. 241—246. Defronzo, R.A., Bonadonna, R.C., Ferrannini, E., 1992. Pathogenesis of NIDDM. A balanced... 

At least five concentrations of each of the expected oxygenates should be prepared. The standards should be as equally spaced as possible within the range and may contain more than one oxygenate. A blank for zero concentration assessments must also be included before each standard. Additional standards should be prepared for other oxygenates of concern. 

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