Synthetic linear

An aqueous solution of APVP was highly viscous, and the reduced viscosity was rather insensitive to polymer concentration, unlike that of usual synthetic linear polyelectrolytes17,18. This suggests that the model compounds were rather stiff in solution, which would be due to the bulkiness and the hydrophobieity of side groups. The stiffness of APVP was also demonstrated by similar insensitivity of the viscosity toward temperature. 

Common biodegradable polymers for medical devices are constructed from synthetic linear aliphatic polyesters. One material commonly used for internal sutures is poly(glycolic acid) (PGA). PGA is synthesized from the dimer of glycolic acid (Fig. 13.1.l). 1... 

In our original column on this topic [1] we had only done a principal component analysis to compare with the MLR results. One of the comments made, and it was made by all the responders, was to ask why we did not also do a PLS analysis of the synthetic linearity data. There were a number of reasons, and we offered to send the data to any or all of the responders who would care to do the PLS analysis and report the results. Of the original responders, Paul Chabot took us up on our offer. In addition, at the 1998 International Diffuse Reflectance Conference (The Chambersburg meeting), Susan Foulk also offered to do the PLS analysis of this data. 

Table 33-1 Summary of results obtained from synthetic linearity data using one PCA or PLS factor. We present only those performance results listed by the data analyst as Correlation Coefficient and Standard Error of Estimate...

These synthetic linear and branched molecules may be important as type polymers, particularly if the interconversion of amylose to amylopectin is intramolecular, in which case the initial molecular weight and molecular-weight distribution would be retained. There is the possibility that the in vitro synthesis may even result in a truly three-dimensional structure, as distinct from that of the natural component. 

Synthetic linear dihydroxamic acids may be considered as models of rhodotorulic acid (3) to investigate steric effects on the formation of mono- or di-iron(III) species (127,128). pH-dependent electrospray ionization-mass spectrometry (ESI-MS) methods show that ferric complexes with dihydroxamates with short linker chains (37 and 38 in Fig. 15) will prefer the dimeric... 

Carothers WH, Hill W. Studies of polymerization and ring formation, xv. Artificial fibers from synthetic linear condensation superpolymers. JAm Chem Soc. 1932 Apr l 54(4) 1579-87. 

Kunitake, T., Enzyme-like Catalysis by Synthetic Linear Polymers, Chap. 4 in Polymer-Supported Reactions in Organic Synthesis, P. Hodge and D. C. Sherrington, eds., Wiley, New York, 1980. 

Indeed, at very high polymer concentrations enhancement of these effects occurs. Recent studies by Franks et al. 23) on the rheological behaviour and freeze fracture electron microscopical analysis of several synthetic linear flexible polymers, including poly(vinylpyrrolidone) and polyethylene glycol) in concentrated solutions, suggest that these molecules do not form a network mesh but rather exhibit aggregation. Anionic polysaccharides, on the other hand, are known to form an anisotropic packing array in condensed films. These films may be stretched to enhance orientation and be used for X-ray diffraction studies... 

The first commercial synthetic linear step reaction or condensation polymer was a polyamide (nylon 66) synthesized by Carothera in... 

Several laboratories have described systems by which synthetic linear peptide chains self-assemble into desirable secondary and tertiary structures. One self-assembly approach has been the creation of a peptide-amphiphile, whereby a peptide head group has the propensity to form a distinct structural element, while a lipophilic tail serves to align the peptide strands and induce secondary and tertiary structure formation, as well as providing a hydrophobic surface for self-association and/or interaction with other surfaces. The preparation of a dialkyl ester tail first involves the acid-catalyzed condensation of H-Glu-OH with the appropriate fatty acid alcohol to form the dialkyl ester of H-Glu-OH a typical example is shown in Scheme 7. The assembly of peptide-amphiphiles with mono- and dialkyl ester tails is shown in Scheme 8. A series of studies have demonstrated that triple-helical and a-helical protein-like molecular architecture is stabilized in the peptide-amphiphile 44,63-65 ... 

Since the work of Kelly, there have been very few reports that focus upon applications of synthetic linear templates to chemical synthesis. Most recent studies have focused on systems that self-replicate [13]. A synthetic system based on a barbituric acid has been shown to organize two cinnamates in apolar media, by way of N-H N and N-H O forces, for a regiocontrolled [2 + 2] ultraviolet-(UV) induced cycloaddition reaction (Figure 3b) [16]. Similar to the system of Kelly, a mixture of products was attributed to free rotation about C-C bonds of the reactants. 

The interaction between con A and a-mannans from a variety of micro-organisms was studied by So and Goldstein.204 The mannans from Saccharomyces cerevisiae, Saccharomyces rouxii, and Sarcina sp., and the phosphomannan from Saccharomyces pini Y-2579, all gave classical precipitin curves similar to those obtained for dextrans,320,362 but unlike the extended curves given by glycogen.369 A synthetic, linear (1—>3)-a-D-mannopyranan did not precipitate204 with con A. 

Bioconjugates play an important role in several fields of biomolecular and biomedicinal sciences. Protein/polypeptide-based conjugates with covalently attached epitope peptides are considered as potential synthetic vaccine candidates and/or target antigens in affinity-based bioassays (e.g., ELISA, BIACORE) (1,2). Drugs such as daunomycin, methotrexate, and a GnRH analog coupled either to monoclonal antibodies or to synthetic linear or branched polypeptides... 

The degree of precipitation with the synthetic linear dextran as compared with the usual native dextrans has been of value in examining anti-dextrans produced in humans, - and in rabbits - and has shown that the heterogeneous populations of antidextran may be mixtures of molecules with specificities directed toward internal chains of a-(1 6) linked residues as well as those with specificities directed toward terminal nonreducing ends of chains. Fractions of such antibodies separated by isoelectric focusing were found to differ in the proportions of their antibodies precipitable by the synthetic linear dextran. 

This section is constrained to synthetic linear polymers whose molecules consist of repeating monomeric units of one or very few kinds (as opposed to natural polymeric substances). A few examples of adsorption of natural macromolecules (proteins, humic substances) are presented in Table 4.4 (organic compounds). 

Interesting colours for mass dyeing of synthetic linear PA are obtained by using 1 2 chromium complexes of 0,01 - dioximonoazo-dyes of benzolazo - 1-phenyl - 3-methylpyrasolon and/or bcnzolazonaphthalene series [98] and chromo - ferrous complex [99]. 

Patent of FRG No 1903244. Method of synthetic linear polyamide dyeing in mass (1978) (in Russian). 

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