Polymerization perturbed

ATP HYDROLYSIS LINKED TO ACTIN POLYMERIZATION PERTURBS THE THERMODYNAMICS OF REVERSIBLE POLYMERIZATION... 

Thus, the mucolytic agent iV-acetyl-L-cys-teine is predicted to have a potential to induce allergic contact dermatitis by virtue of the biophore SH—CHg (Fig. 19.5). Moreover, examination of the chemicals that contribute to that toxicophore reveals that indeed they all have the substructure in an environment that is similar to the one found inN-acetyl-L-cysteine (Table 19.3). On the other hand, the tubulin polymerization perturber (and potential anti-neoplastic agent) epitholone A (Fig. 19.6) is predicted to be a mouse carcinogen by virtue of the toxicophore units shown in bold. That toxicophore is present in five molecules in the learning set. The presence of that toxicophore... 

Presently we have no exact values for the rate constants of the polymeric reactions (P2)-(P5) however, these measurements are in progress. Also some modifications in the MBM mechanism can be expected 1,4), Nevertheless, the present semiquantitative calculations applying estimated rate constants prove that the assumed mechanism of the polymeric perturbations qualitatively predicts the observed perturbation effects due to the polymers. Simulation results are shown in Figure 4. In Figure 4A Ce(IV) oscillations of the unperturbed BZ system are depicted. The perturbation effect due to the polymer backbone reaction is shown separately in Figure 4B. It causes a shortening of the induction... 

Wertheim M S 1987 Thermodynamic perturbation theory of polymerization J Chem. Phys. 87 7323... 

An Experimental Study Using Feed Perturbations for a Free-Radically Initiated Homogeneous Polymerization in a Continuous-Flow Stirred-Tank Reactor... 

Control Policy. The control variables which, if perturbed, are most likely to influence the MWD of the product of a free radically initiated solution polymerization carried out in a well mixed CSTR are ... 

The influence of changes in these other variables on MWD in a homopolymerization has not yet been tested, but whatever perturbations are introduced to the feed in a radical polymerization in a laboratory-scale CSTR, they are unlikely to introduce dramatic changes in the MWD of the product because of the extremely short life-time of the active propagating chains in relation to the hold-up time of the reactor. This small change in MWD could be advantageous in a radically initiated copolymerization where perturbations in monomer feeds could give control over polymer compositions independent of the MWD. This postulate is being explored currently. 

The second procedure, several aspects of which are reviewed in this paper, consists of directly computing the asymptotic value by employing newly-developed polymeric techniques which take advantage of the one-dimensional periodicity of these systems. Since the polarizability is either the linear response of the dipole moment to the field or the negative of the second-order term in the perturbation expansion of the energy as a power series in the field, several schemes can be proposed for its evaluation. Section 3 points out that several of these schemes are inconsistent with band theory summarized in Section 2. In Section 4, we present the main points of the polymeric polarization propagator approaches we have developed, and in Section 5, we describe some of their characteristics in applications to prototype systems. 

These treatments of periodic parts of the dipole moment operator are supported by several studies which show that, for large oligomeric chains, the perturbed electronic density exhibits a periodic potential in the middle of the chain whereas the chain end effects are related to the charge transfer through the chain [20-21]. Obviously, approaches based on truncated dipole moment operators still need to demonstrate that the global polarization effects are accounted for. In other words, one has to ensure that the polymeric value corresponds to the asymptotic limit of the oligomeric results obtained with the full operator. 

Sundqvist B (2004) Polymeric Fullerene Phases Formed Under Pressure 109 85-126 Szalewicz K, Patkowski K, Jeziorski B (2005) Intermolecular Interactions via Perturbation Theory From Diatoms to Biomolecules 116 43-117... 

Bishop MF, Ferrone FA. Kinetics of nucleation-controlled polymerization. A perturbation treatment for use with a secondary pathway. Biophys J 1984 46 631-644. 

The other two approaches divide the excess functional into a hard-core and an attractive part with different approximations for the two. Rosinberg and coworkers [126-129] have derived a functional from Wertheim s first-order perturbation theory of polymerization [130] in the limit of complete association. Woodward, Yethiraj, and coworkers [39,131-137] have used the weighted density approximation for the hard-core contribution to the excess free energy functional, that is,... 

Personal exposure limit (PEL), for nickel compounds, 17 120. See also Permissible exposure limits (PEL) Personal hazard protection, 21 838 Personnel. See also People commitment of, 15 474 health and safety of, 21 826-827 selection and training of, 21 857 training requirements for, 24 345-347 Persulfate redox initiation, in aqueous dispersion polymerization, 11 197-198,199 Persulfates, 18 408 26 189-190 Persulfate salts, 18 409 Persulfuric acid, 18 407—408 Perturbation... 

On the other hand, when sCL is copolymerized with dilactones such as GA [38] and (D- andD,L-)LA [39], tapered or pseudoblock copolymers are obtained with a reactivity ratio much in favor of the dilactone. As an example, the reactivity ratios in the copolymerization of eCL and D,L-LA in toluene at 70 °C are r = 0.92 (e-CL) and r2=26.5 (D,L-LA). Very similar reactivity ratios were calculated for copolymerization between eCL and L-LA, other experimental conditions being kept unchanged. However the control over the polymerization is lost due to transesterification side reactions perturbing the propagation step. Such a behav-... 

Sequential IPN. The preceding analysis does not apply to the case of a sequential IPN. The formation of this system originates with the synthesis of the network (1). Then, network (1) is swollen with monomer (2) which is subsequently polymerized in situ to form a second network. Due to perturbed chain dimensions, the modulus of the first network is higher than the corresponding modulus in the unswollen state by a factor equal to v [ ] ... 

A procedure used to assess the processivity of nucleic acid polymerases In this method, the investigator perturbs the polymerization reaction proceeding on one template by the addition of a new template. See Processivity... 

Miller, S. A., Metallocene-Mediated Olefin Polymerization The Effects of Distal Ligand Perturbations on Polymer Stereochemistry, PhD. Thesis, California Institute of Technology, Pasadena, 2000. 

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