Composite curves biology

Sedimentation FFF, applied in the above manner, yields highly detailed size distribution curves. It is convenient and accurate. Importantly, sedimentation FFF is a highly flexible technique. It can be adapted to nearly all particle types in virtually any suspending medium. It yields particle density as well as size and size distribution. Our recent work has shown that it can be used to probe both size and density distributions in complex colloids, defined as systems having colloidal particles of variable chemical composition. Complex colloids are important in many biological and environmental studies. 

Selectivity in HPLC is obtained by setting optimal chromatographic conditions, such as mobile phase composition, column temperature, and detector wavelength. There are a variety of ways to validate selectivity. One approach is to demonstrate a lack of response in the blank biological matrix. A second approach is to check whether the intercept of the calibration curve is significantly different from zero. 

The accuracy and precision decrease for ill-shaped waves. If, moreover, the composition of the sample with respect to electro-inactive materials that affect the shape of polarographic curves varies from sample to sample (e.g., in samples of biological materials), the error may increase to 5% or even to 20%. However, even this level is often sufficient for clinical analysis, studies of natural products, or other biochemical applications. 

FIGURE 5 Dependence of the cmc and average micelle size on ionic strength and counterion at 25°C. Curve 1, Na dodecyi sulfate with added NaCI curve 2, dodecyltrimethylammonium bromide with added NaBr and curve 3, dodecyitrimethylammonium chloride with added NaCI. [Composite from Tanford, C. (1980). The Hydrophobic Effect Formation of Miceiies and Biological Membranes, Wiley, New York.]... 

Fig. 19.1. Impact of heterogeneity in biological characteristics of tumors on dose-response for local tumor control probability (TCP). Nine different human head and neck squamous cell carcinomas in nude mice were irradiated at the same size with 30 fractions in 6 weeks. Despite that all tumors are of the same entity, the dose relationships differ substantially in position and steepness. The bold curve represents the composite dose-response relationship of all nine tumor lines...

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