Shunt equation

The purpose of the shunt equation is to give a ratio of shunt blood flow to total blood flow. The normal ratio is 0.3. Under abnormal conditions, the ratio will tend to increase and so markedly reduce the Pao2. 

The P(A-a) 2 also used in calculating the amount of shunt present (equation 8)... 

Normally the shunt is 2-6% for room air conditions equation 9 becomes... 

The 02 content of the mixed venous (shunt) and arterial blood can be calculated from the relevant samples by using the equations below, which are explained later in the section. 

Ortiz-Conde A, Sanchez FJG, Muci J (2000) Exact analytical solutions of the forward nonideal diode equation with series and shunt parasitic resistances. Solid-State Electron 44 1861 Jain A, Kapoor A (2004) Exact analytical solutions of the parameters of real solar cells using Lambert W-function. Sol Energy Mater Sol Cells 81 269... 

When R2 R, the polymer is more conducting than the pores. The Randles circuit, which is located at the polymer/electrolyte interface (case b), shunts the resistive ionic rail through the polymer. At high frequencies, the equation can be simplified to... 

In a very imaginative piece of research Frost and coworkers have developed a plasmid-based method for synthesizing aromatic amino acids, by incorporating the genes that code for the enzymes that perform the series of conversions from D-fructose-6-phosphate to D-erythrose-4-phosphate to 3-deoxy-D-arabinoheptulosonic acid-7-phos-phate (DAHP) near each other on a plasmid that can be transformed in E. coli. The enzymes are the thiamin diphosphate-dependent enzyme transketolase in the nonoxida-tive pentose shunt and DAHP synthase. The DAHP is then converted to the cyclic dehydroquinate, a precursor to all aromatic amino acids L-Tyr, L-Phe and L-Trp165,166 (equation 27). 

The P450 shunt pathway and peroxygenase activity of peroxidases share identical overall reaction equations. P450s generally have high Km values for H 202 values of 15 mM... 

The loss terms in N-cycle models that transform particulate and dissolved organic nitrogen into other forms can include a variety of processes (e.g., phytoplankton exudation, zooplankton grazing, sloppy feeding, phytoplankton and zooplankton mortality, bacterial remineralization, etc.). Different models may differ substantially in terms of which of these are included and their formulation (Christian and Anderson, 2002). Many N-cycle models now include significant phytoplankton exudation loss terms. This is often parameterized by simply specifying that some fixed fraction of the DIN uptake by phytoplankton is shunted directly to the DON pool (e.g., Anderson and Williams, 1998). Sloppy feeding by zooplankton can be similarly accounted for. Many models also include linear loss terms in the phytoplankton equation that represent either natural mortality or phytoplankton respiration (e.g.. Hood et ai, 2001). 

When portosystemic shunting is present total hepatic blood flow (Q) equals the sum of perfusion flow (Q ) and shunt flow (Qs). Portocaval shunting will impair the efficiency of hepatic extraction and reduce the extraction ratio as indicated by the following modification of Equation 7.5 (23). 

Equation 7.13 emphasizes the central point that changes in perfusion and protein binding, as well as intrinsic clearance, will affect the hepatic clearance of a number of drugs. The intact hepatocyte theory has been proposed as a means of simplifying this complexity (33). This theory is analogous to the intact nephron theory (see Chapter 5) in that it assumes that the increase in portocaval shunting parallels the loss of functional cell mass, and that the reduced mass... 

Calculation of Uterine and Umbilical 02 Tensions with Vascular Shunts. Vascular shunting could also explain the po2 of uterine vein being greater than that of umbilical vein, despite equilibration in endcapillary blood predicted by our model. The equations allowing one to calculate the effect of shunts on the placental V-o difference are ... 

Using these equations one finds that a 26% shunt on maternal and fetal placental sides of the placenta results in values of uterine and... 

The -V characteristics of this PV device in the dark and under 0.9 suns of simulated AM1.5 solar illumination are shown in Figure 12.7b. The device shows excellent rechfying behavior in the dark with a rectification ratio of approximately 10 at 1V, and has a very low leakage current, corresponding to a shunt resistance l sh 1 MO cm. The dark J-V characteristics can be well described using the modified diode equation (Sze and Ng, 2007) ... 

Equations (3.36) and (3.37) represent stock balances for loaded and unloaded RTCs. Both stocks are interconnected by RTC transfer flows rz and rz. E.g. unloading of RTCs in period t at site i immediately reduces the number of loaded RTCs. However, t periods are required for unloading and shunting before these RTCs can be handled as empty RTCs again. Both stocks are replenished by incoming RTCs from other sites... 

Equation (IL5.36) shows that the Warburg impedance cannot be represented as a series combination of frequency-independent elements in an equivalent circuit. This is possible, however, by a semi-infinite resistive-capacitive transmission line with a series resistance R per unit length and a shunt capacity C per unit length (Fig. IL5.4). 

Although most of the glucose catabolised in animal tissues is via glycolysis to pyruvate which then enters the Krebs cycle, there are some minor metabolic pathways which lead to alternative products. One of the most important of these is the Pentose Phosphate pathway (also known as the pentose shunt or the phosphogluconate pathway). In this pathway, glucose-6-phosphate is oxidised to ribose-5-phosphate with the generation of two molecules of NADPH. The overall equation may be written as... 

Sah [1970] introduced the use of networks of electrical elements of infinitesimal size to describe charge carrier motion and generation/recombination in semiconductors. Barker [1975] noted that the Nemst-Planck-Poisson equation system for an unsupported binary electrolyte could be represented by a three-rail transmission line (Figure 2.2.8fl), in which a central conductor with a fixed capacitive reactance per unit length is connected by shunt capacitances to two resistive rails representing the individual ion conductivities. Electrical potentials measured between points on the central rail correspond to electrostatic potential differences between the corresponding points in the cell while potentials computed for the resistive rails correspond to differences in electrochemical potential. This idea was further developed by Brumleve and Buck [1978], and by Franceschetti [1994] who noted that nothing in principle prevents extension of the model to two or three dimensional systems. 

The shunt model [59] is proposed by taking into account the shunting effect of the electrode that is, the potential on the electrode is constant. In addition, in the shunt model, the boundary condition represented by the continuum (Equation 30.3) model is modified with a more reliable condition given by... 

To obtain better EIT results in a real subject, the complete electrode model is proposed. The complete electrode model works by taking into account both the shunting effect of the electrodes and the contact impedances for the electrode-electrolyte interface [59]. The complete electrode model consists of Equation 30.1 and the boundary conditions as follows ... 

The L network is shown in Fig. 13.39 The loaded Q of the networkis determined from Equation 1. Equation 2 defines the shunt leg reactance, which is negative (capacitive) when 9 is negative, and positive (inductive) when 9 is positive. The series leg reactance is found using Equation 3, the phase shift via Equation 4, and the currents and voltages via Ohm s law. Note that R2 (the resistance on the shunt leg side of the L network) must always be greater than An L network cannot be used to match equal resistances, or to adjust phase independently of resistance. 

Equations 5 through 14 describe the tee network. It is a simple matter to find the input and output currents via Ohm s law, and the shunt leg current can be found via the Cosine law (Equation 12). Note that this current increases with increasing phase shift. Equation 13 describes the mid-point resistance of a tee network, which is always higher than Ri or Rj. Equation 14 is useful when designing a. phantom tee network that is, where X2 is made up only of the antenna reactance and there is no physical component in place of X2. Keep in mind that a tee network is considered as having a lagging or negative phase shift... 

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