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Indicator function identities involving

A powerful tool now employed is that of diode array detection (DAD). This function allows peaks detected by UV to be scanned, and provides a spectral profile for each suspected microcystin. Microcystins have characteristic absorption profiles in the wavelength range 200-300 nm, and these can be used as an indication of identity without the concomitant use of purified microcystin standards for all variants. A HPLC-DAD analytical method has also been devised for measurement of intracellular and extracellular microcystins in water samples containing cyanobacteria. This method involves filtration of the cyanobacteria from the water sample. The cyanobacterial cells present on the filter are extracted with methanol and analysed by HPLC. The filtered water is subjected to solid-phase clean-up using C g cartridges, before elution with methanol and then HPLC analysis. [Pg.118]

There is no doubt that this dispersion effect occurs but the magnitude of the spectral differences appear in most cases to be considerably larger than would be predicted by dispersion effects. For example, the poly(e-caprolactone) (PCL) and poly (vinyl chloride) (PVC) blend has been studied 252,253) and for this system the refractive indices are identical. In this case, there are obvious frequency shifts and broadening of the carbonyl band as a function of PVC concentration as shown in (Fig. 21). Nine percent of the original area of the carbonyl peak is involved in the shifted frequency absorption. Clearly, for this system, chemical interaction effects are being observed. In fact, PCL can be viewed as a macromolecular plasticizer for PVC. The blend system polyO-propiolactone) PPL and PVC was studied 2S3). In contrast to the PCL/PVC system, the PPL/PVC system was incompatible over the entire range of compositions. [Pg.132]

There are three main methods for calculating electron correlation Configuration Interaction (Cl), Many Body Perturbation Theory (MBPT) and Coupled Cluster (CC). A word of caution before we describe these methods in more details. The Slater determinants are composed of spin-MOs, but since the Hamilton operator is independent of spin, the spin dependence can be factored out. Furthermore, to facilitate notation, it is often assumed that the HF determinant is of the RHF type. Finally, many of the expressions below involve double summations over identical sets of functions. To ensure only the unique terms are included, one of the summation indices must be restricted. Alternatively, both indices can be allowed to run over all values, and the overcounting corrected by a factor of 1/2. Various combinations of these assumptions result in final expressions which differ by factors of 1 /2, 1/4 etc. from those given here. In the present book the MOs are always spin-MOs, and conversion of a restricted summation to an unrestricted is always noted explicitly. [Pg.101]

Figure 4. Alignment of PelZ and PelC amino acid sequences. The vertical lines indicate identical amino acids and the two points indicate homologous amino acids. The bold letters correspond to the residues probably involved in Ca + binding or catalytic function(s). The two aspartate residues probably involved in Ca binding are indicated with an asterisk. The invariant residues, probably involved in PGA cleavage, are indicated with an open circle. The folding in p-sheets is characterised by the underlined amino acids. Double underlining of PelZ residues is deduced from Chou Fasman and Robson Gamier folding predictions. Figure 4. Alignment of PelZ and PelC amino acid sequences. The vertical lines indicate identical amino acids and the two points indicate homologous amino acids. The bold letters correspond to the residues probably involved in Ca + binding or catalytic function(s). The two aspartate residues probably involved in Ca binding are indicated with an asterisk. The invariant residues, probably involved in PGA cleavage, are indicated with an open circle. The folding in p-sheets is characterised by the underlined amino acids. Double underlining of PelZ residues is deduced from Chou Fasman and Robson Gamier folding predictions.
Mammalian COX (the illustration shows the enzyme from bovine heart) is a dimer that has two identical subunits with masses of 204 kDa each. Only one subunit is shown in detail here the other is indicated by gray lines. Each subunit consists of 13 different polypeptides, which all span the inner mitochondrial membrane. Only polypeptides I (light blue) and II (dark blue) and the linked cofactors are involved in electron transport. The other chains, which are differently expressed in the different organs, probably have regulatory functions. The two heme groups, heme a (orange) and heme ai (red) are bound in polypeptide 1. The copper center Cua consists of two copper ions (green), which are coordinated by amino acid residues in polypeptide II. The second copper (Cub) is located in polypeptide I near heme... [Pg.132]

The first step in the solution procedure is discretization in the radial dimension, which involves writing the three-dimensional differential equations as an enlarged set of two-dimensional equations at the radial collocation points with the assumed profile identically satisfying the radial boundary conditions. An examination of experimental measurements (Valstar et al., 1975) and typical radial profiles in packed beds (Finlayson, 1971) indicates that radial temperature profiles can be represented adequately by a quadratic function of radial position. The quadratic representation is preferable to one of higher order since only one interior collocation point is then necessary,6 thus not increasing the dimensionality of the system. The assumed radial temperature profile for either the gas or solid is of the form... [Pg.133]

The pH dependence of Ks/Km is similar for step 1 and step 2 reactions as shown in Fig. 26b, but this similarity in the pH curves indicate only that the same titratable groups on the free enzyme and/or free substrate are involved in the two steps. As discussed explicitly by Usher et al. (522) the roles of the two histidines could be reversed and this would make no difference since the ratio of HE EH where these are the two singly protonated species is independent of pH. Similar ks and Ka curves for the two steps would also fail to prove identical roles for the two histidines. Since a pentacovalent species—whether it is a transient activated complex or a more stable intermediate—is common to the various alternatives, pK shifts deduced from ka curves could be the same. Both substrates are monovalent anions with low pK values so that 1 /Km, whether interpreted as an equilibrium binding value or as a function of the kinetic parameters mirroring the total occupancy of all the stable intermediates, could also be the same for both steps. The values for the reverse of step 2 would behave differently since the pj of 3 -CMP, for example, is 5.9. It should also be noted that ks/Km curves should be and are ionic strength dependent (508) in the same way that the His 12 and His 119 pK values are as observed by NMR (280). [Pg.790]

It was noted that the N-tcrminal end of /i. mori PBAN was identical to the incomplete sequence of melanization and reddish coloration hormone (MRCH) also isolated from B. mori. Subsequently, it was shown that B. mori PBAN is the same peptide as MRCH (Matsumoto et al 1990). This was the first indication that these peptides were involved in multiple functions. [Pg.109]


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Indicator function

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