Curve, area under

Fig. 3.28 The Kiselev method for calculation of specific surface from the Type IV isotherm of a compact of alumina powder prepared at 64 ton in". (a) Plot of log, (p7p) against n (showing the upper (n,) and lower (n,) limits of the hysteresis loop) for (i) the desorption branch, and (ii) the adsorption branch of the loop. Values of. 4(des) and /4(ads) are obtained from the area under curves (i) or (ii) respectively, between the limits II, and n,. (6) The relevant part of the isotherm.

The values for both P.I.G. and P.S.G. are computed from the areas under curves generated, using impact sensy devices, by plotting the num-... 

In the total plasma response approach, the bioavailability of a compound is determined by measuring its plasma concentration at different times (up to weeks) after single or long-term ingestion of the compound from supplements or food sources. Generally, a plasma concentration-versus-time plot is generated, from which is determined the area-under-curve (AUC) value used as an indicator of the absorption of the componnd. Here, the term relative bioavailability is more appropriate since AUC valnes of two or more treatments are usually compared. This is in contrast to absolnte bioavailability for which the AUC value of the orally administered componnd is compared to that obtained with intravenous administration taken as a reference (100% absorption). 

ATHERO-ELAM A montxyte adhesion molecule ATL Adult T cell leukaemia ATP Adenosine triphosphate ATPase Adenosine triphosphatase ATP-ys Adenosine 3 thiotriphosphate AITP Autoimmune thrombcKytopenic purpura AUC Area under curve AVP Arginine vasopressin... 

Obtaining Eft), t, and of from experimental tracer data involves determining areas under curves defined continuously or by discrete data. The most sophisticated approach involves die use of E-Z Solve or equivalent software to estimate parameters by nonlinear regression. In this case, standard techniques are required to transform experimental concentration versus time data into Eft) or F(t) data the subsequent parameter estimation is based on nonlinear regression of these data using known expressions for Eft) and F t) (developed in Section 19.4). In the least sophisticated approach, discrete data, generated directly from experiment or obtained from a continuous response curve, are... 

Figure 7. Comparison of (a, solid) electrochemical and (b, dashed) UHV measurements of the H, coverage/potentiaI differential versus potential on Pt(lll).1.) cathodic sweep (25 mV/s) voltammogram in 0.3 M HF from Ref. 20, constant double layer capacity subtracted, b.) dB/d(A ) versus A plot derived from A versus B plot of Ref. 26. Potential scales aligned at zero coverage. Areas under curves correspond to a.) 0.67 and b.) 0.73 M per surface Pt atom.

Additionally, with the inclusion of computers as part of an instrument, mathematical manipulation of data was possible. Not only could retention times be recorded automatically in chromatograms but areas under curves could also be calculated and data deconvoluted. In addition, computers made the development of Fourier transform instrumentation, of all kinds, practical. This type of instrument acquires data in one pass of the sample beam. The data are in what is termed the time domain, and application of the Fourier transform mathematical operation converts this data into the frequency domain, producing a frequency spectrum. The value of this methodology is that because it is rapid, multiple scans can be added together to reduce noise and interference, and the data are in a form that can easily be added to reports. 

AUC, area under curve of plasma concentration Av, avidin NLA, neutral avidin SA, streptavidin cHSA, cationized human serum albumin HIR MAb, human insulin receptor mAb PS product, permeability surface area product. 

Figure 3-5 Residence times in CSTR (shaded rectangle) and PFTR (area under curve) from the 1/r plot.

Let us return to the graphical construction we developed in earlier chapters for isothermal reactors, because for nonisothermal reactors T is stiU the area under curves of plots of 1/r versus Cao — CA. For the first-order irreversible reaction in an adiabatic reactor 1/fad is given by... 

Figure 3.3 Determination of area under curve (AUC) of a compound in the body (see Table 3.1 for calculations).

The area under curve for the sample (AUCsaj pie), reduced by the area under curve plotted for the blank sample (AUCbianJ is referred to as "net AUC". Moreover, the net AUC is calculated for a series of dilutions of Trolox and a calibration curve is plotted, showing the relationship between net AUC and the concentration of Trolox. The results of the assay which refer the net AUC of the sample to the calibration curve are expressed as Trolox equivalent. 

FIGURE 9.12 Meaning of standard deviation for a normal distribution. The hatched area represents 68% of total area under curve. 

Area under curve (AUC] The total area under the plot-of-drug concentration versus time following either a single dose or multiple doses of a specific drug product (e.g., formulation) in a specific patient by a specific route of administration. 

The results of the analysis of one SBS sample are summarized in Table III, in which the ultraviolet optical density and the average height in GPC obtained from the area under curve are listed for each fraction in columns 2 and 3, respectively. A conversion factor of 7.2 obtained from polystyrene (PS) calibration was used to convert the optical density to the styrene contribution to the average chromatogram height which is tabulated in column 4. The difference between columns 3 and 4 was taken as the relative weight of butadiene after being multiplied by 1.37, a correction for the difference in refractive indices of styrene and butadiene (column 5). 

From day 6 onwards, the slope of the curve corresponds to the effective half-life of 131I on herbage, namely 5 d. Assuming that this continues indefinitely, the area under curve A in Fig. 3.6 is 1.4 m2 d l-1. This is equivalent to the transfer factor km, defined by equation (2.12). Values of Fm for 131I and 137Cs are about the same, but the radioactive decay of 131I reduces km compared with that for137Cs (Table 2.19). Also shown in Fig. 3.6 are values of C/ as deduced from measurements near... 

ORAC R-Phycoerythrin ABAP Fluorimetric (area under curve) C6, C15... 

TOSC assay KMBA ethylene ABAP Gas chromatography (area under curve) W12... 

Fig. 4. Various ways of quantitation of TAC in inhibition assays measurement of induction time, absorbance (fluorescence) after fixed time, and area the kinetic curve of time course of changes in absorbance or fluorescence. Dashed line, reference solid line, sample measured. Differences between the areas under curves for sample and reference (protection area) indicated only.

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