Partial specific volume of thermotropic polybibenzoates with different spacers

Summary Partial specific volume (v ₂ ^o ) of polybibenzoates with all-methylene and oxyethylene spacers have been determined in chloroalifatic solvents. The polybibenzoate with a heptamethylene spacer exhibits a more expanded state than the ones with one, two and three oxyethylene units in the spacer. A solvent effect on v ₂ ^o has been observed. Nevertheless, the values of v ₂ ^o in tetrachloroethane are in accord with the calculated by group contributions from rubbery polymers.     

Partial specific volume of poly(D-β-hydroxybutyrate) in chloroaliphatic solvents

Partial specific volumes, v ⁰₂, of poly(D -β-hydroxybutyrate), PHB, were determined by density measurements in several chloroaliphatic hydrocarbons. We observed that v ⁰₂ of PHB in tetrachloroethane is influenced only very little by temperature. This can be generalized for the group of solvents used. The experimental results are comapred with the data obtained theoretically using the concept of additivity of group contributions.     

Synthesis and characterization of novel polyarylates bearing NLO moieties

A series of thermally stable second‐order nonlinear optical polyarylates containing azo side‐chain groups have been obtained by interfacial polycondensation. Theoretical calculations of the static hyperpolarizabilities, first‐ and second‐order hyperpolarizability, were carried out. The structures of the obtained monomers and polymers were confirmed by infrared, ¹H NMR and ultraviolet spectroscopies. Thermal and optical properties of the obtained polymers were evaluated. The investigations show that some of the new polymers obtained in this study may find use in optical applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2195–2201, 2006     

Reactions of hydroxymethyl derivatives of uric acid with oxiranes. II. An analysis of reaction course and product structure

Polyetherols containing thermostable purine rings are obtained in reactions of hydroxymethyl derivatives of uric acid with an excess of ethylene oxide or propylene oxide. By using elementary analytical tools and ¹H‐NMR spectroscopy, it was possible to follow the course of reaction at various molar ratios of reagents. A migration of formaldehyde molecules from N‐hydroxymethyl groups or from oligooxymethylene bridges to the end of oxyalkyl chains was observed. At the same time, the O‐hydroxymethyl groups are successively blocked by oxiranes. The most probable structure of polyetherols is proposed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1955–1962, 2002     

The Role of NLRP1, NLRP3, and AIM2 Inflammasomes in Psoriasis: Review

Inflammasomes are high-molecular-weight protein complexes that may cleave the two main proinflammatory cytokines, pro-interleukin-1β and pro-interleukin-18, into active forms, and contribute to psoriasis. Despite recent advances made in the pathogenesis of psoriasis, mainly studied as an autoimmune condition, activation of immune response triggers of psoriasis is still not completely understood. Recently, focus was placed on the role of inflammasomes in the pathogenesis of psoriasis. Multiple types of inhibitors and activators of various inflammasomes, inflammasome-related genes, and genetic susceptibility loci were recognized in psoriasis. In this systemic review, we collect recent and comprehensive evidence from the inflammasomes, NLRP1, NLRP3, and AIM2, in pathogenesis of psoriasis.     

UV-Sensitive polyarylates as photolithographic emulsions

Several UV-sensitive polyarylates based on bisbenzylidenoketones for use as potential pho-tolithographic emulsions were obtained by interfacial polycondensation. The structures of obtained UV-sensitive monomers and polymers were confirmed by infrared, ¹H-NMR, and UV spectroscopies. Mechanical and dielectric properties of the obtained polyarylates (in-cluding dielectric loss factor, dielectric constant, volume and surface resistivity, and dielectric strength) were evaluated. The investigations show that some of the new polymers obtained in this study may find application as photoresists. © 1996 John Wiley & Sons, Inc.     

Reactions of hydroxymethyl derivatives of uric acid with oxiranes. I. Synthesis of polyetherols with purine rings

Preliminary results on the utilization of uric acid in the synthesis of a new group of polyetherols with purine rings are presented. The polyetherols were prepared in a two‐stage process. First, hydroxymethyl derivatives of uric acid were obtained from an uric acid and formaldehyde solution. This intermediate was then reacted with ethylene oxide or propylene oxide without any additional solvent. The structure of the intermediates and polyetherols and some of their physical properties were determined, and the possibilities of application of the polyetherols in manufacturing thermostable polyurethane foams were tested. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2667–2677, 2000     

The potentiodynamic investigations of the overcharge and self-discharge of nickel hydroxide electrode

Potentiodynamic investigations of the nickel hydroxide electrodes were carried out. We have tried to explain the mechanisms of the overcharge and self-discharge of these electrodes.     

Comparitative Research of Pollen Morphology of Common Flax Cultivars (Linum usitatissimum L., Linaceae)

Pollen morphology of 11 cultivars of different purpose use of Linum usitatissimum was studied with LM and SEM microscopy. On average, pollen grains were radially symmetrical, isopolar, and prolate spheroidal in shape, tricolpate and of large size. All grains were semitectate with discontinuous tectum due to partial fusion of heads of the clavae. The clavae were dimorphic, clearly differ in size, but morphologically similar. The smaller ones were dominant. All observed cultivars were very similar in pollen structure and the differences among their pollen grains were primarily quantitative.     

The effect of side chains on the partial specific volumes of poly(o-alkylphenyl methacrylate)s and polydiitaconates

Partial specific volumes ν of a series of poly(o-alkyl phenyl methacrylate)s and polydiitaconates were determined by density measurements, in toluene and tetrahydrofuran solutions, respectively. The effect of the size and nature of the side groups on partial specific volume is analyzed. Good agreement is found between the experimental ν values and those obtained theoretically from the group contribution method.