Coil-globule transition in aqueous solutions of quaternized poly(4-vinylpyridine) derivatives and sodium dodecyl sulfate

Aqueous solutions of cationic polyelectrolytes (quaternized derivatives of poly(vinylpyridine)) and an anionic surfactant (sodium dodecyl sulfate) were studied by potentiometric titration using surfactant-selective and bromide-selective electrodes, as well as by the methods of microelectrophoresis, viscometry, spectrophotometry, dye solubilization, and pH control. The experimental evidence obtained revealed a new phenomenon: at a certain concentration of surfactant in polymer solutions, once the macromolecular ion has been saturated with surfactant molecules, a noticeable fraction of surfactant ions is expelled from the polyelectrolyte complex, and the vacant sites are occupied by inorganic counterions. This structural transition was discussed within the framework of the theory of coil-globule conformational transition. Schematic representation of pretransition and posttransition states of the polyelectrolyte-surfactant associates was advanced

Легочный амилоидоз

Amyloidosis is an orphan disease. Amyloidosis is uncommonly associated with respiratory disorders. The present article is a review of recently published data on pulmonary amyloidosis and a case report of alveolar and septal amyloid lung injury. Clinical heterogeneity of lung lesions in systemic and limited AL amyloidosis (precursor proteins are light chains of immunoglobulins, λ dimer and κ monomer), AA amyloidosis (inflammatory acute-phase proteins), and ATTR amyloidosis (senile and inherited amyloidosis; precursor protein is transthyretin) have been discussed. One chart of the review has been devoted to the pathogenesis of diffuse parenchymatous (unilateral and bilateral) amyloidosis, nodular and tracheobronchial amyloidosis (with amyloid deposits in proximal, medium and distal airways, intrathoracic lymph node involvement (amyloid lymphadenopathy), amyloidosis of the pleura and the diaphragm, and differential diagnosis of these types of pulmonary amyloidosis.Амилоидоз относится к классу орфанных заболеваний. Среди других систем организма с амилоидозом в наименьшей степени ассоциирована дыхательная система. Современные данные по проблеме легочного амилоидоза представлены на основе литературного обзора и авторского описания редкого примера альвеолярно-септальной формы поражения легких; рассмотрены вопросы клинической неоднородности пульмонологической патологии при системном и местном амилоидозе (AL – белок-предшественник – легкие цепи иммуноглобулинов, димер λ и мономер κ; АА – воспалительные острофазовые белки; ATTR – старческий и наследственный, белок-предшественник транстиретин). Один из разделов посвящен патогенезу диффузного паренхиматозного (одностороннего и двустороннего), узлового и трахеобронхиального (с депозитами амилоида в проксимальных, средних или дистальных отделах бронхиального дерева) вариантов болезни, вовлечению в процесс внутригрудных лимфатических узлов (амилоидная аденопатия), плевры и диафрагмы, вопросам дифференциальной диагностики данных вариантов легочного амилоидоза

Floristic analysis of a high-speed railway embankment in a Mediterranean landscape

We analyzed the floristic composition of a 4.5 km-long segment of a high-speed railway in Lazio, central Italy, which travels on an artificial embankment through an intensively-farmed landscape. In total, 287 vascular plant species were recorded. The life-form distribution was found to be similar to that of the regional species pool, with high percentages of therophytes (38%) and phanerophytes (13%). In the chorological spectrum the Mediterranean floristic element prevailed (44%), while alien species were 8% of the flora. The phytosociological spectrum showed a high diversity of characteristic species from the class Stellarietea mediae or its subordinate syntaxa (26%), and in particular from the order Thero-Brometalia (Mediterranean, sub-nitrophilous annual communities). Species from forest syntaxa had a relatively high diversity (9%). These results suggest that the ecological filtering provided by the Mediterranean regional climate controlled species assemblage even in a completely artificial habitat, preventing floristic homogenization: the flora of the studied railway section is only partially »ruderalized«, while it keeps strong links with the regional (semi-) natural plant communities. However, in contrast to what is observed in central and north Europe, the railway sides studied in the present paper do not seem to represent a refugial habitat for rare species from grassland communities, mainly because in Italy semi-natural dry grasslands are still widely represented

Coil-globule transition in aqueous solutions of quaternized poly(4-vinylpyridine) derivatives and sodium dodecyl sulfate

Aqueous solutions of cationic polyelectrolytes (quaternized derivatives of poly(vinylpyridine)) and an anionic surfactant (sodium dodecyl sulfate) were studied by potentiometric titration using surfactant-selective and bromide-selective electrodes, as well as by the methods of microelectrophoresis, viscometry, spectrophotometry, dye solubilization, and pH control. The experimental evidence obtained revealed a new phenomenon: at a certain concentration of surfactant in polymer solutions, once the macromolecular ion has been saturated with surfactant molecules, a noticeable fraction of surfactant ions is expelled from the polyelectrolyte complex, and the vacant sites are occupied by inorganic counterions. This structural transition was discussed within the framework of the theory of coil-globule conformational transition. Schematic representation of pretransition and posttransition states of the polyelectrolyte-surfactant associates was advanced

Coil-globule transition in aqueous solutions of quaternized poly(4-vinylpyridine) derivatives and sodium dodecyl sulfate

Aqueous solutions of cationic polyelectrolytes (quaternized derivatives of poly(vinylpyridine)) and an anionic surfactant (sodium dodecyl sulfate) were studied by potentiometric titration using surfactant-selective and bromide-selective electrodes, as well as by the methods of microelectrophoresis, viscometry, spectrophotometry, dye solubilization, and pH control. The experimental evidence obtained revealed a new phenomenon: at a certain concentration of surfactant in polymer solutions, once the macromolecular ion has been saturated with surfactant molecules, a noticeable fraction of surfactant ions is expelled from the polyelectrolyte complex, and the vacant sites are occupied by inorganic counterions. This structural transition was discussed within the framework of the theory of coil-globule conformational transition. Schematic representation of pretransition and posttransition states of the polyelectrolyte-surfactant associates was advanced

Coil-globule transition in aqueous solutions of quaternized poly(4-vinylpyridine) derivatives and sodium dodecyl sulfate

Aqueous solutions of cationic polyelectrolytes (quaternized derivatives of poly(vinylpyridine)) and an anionic surfactant (sodium dodecyl sulfate) were studied by potentiometric titration using surfactant-selective and bromide-selective electrodes, as well as by the methods of microelectrophoresis, viscometry, spectrophotometry, dye solubilization, and pH control. The experimental evidence obtained revealed a new phenomenon: at a certain concentration of surfactant in polymer solutions, once the macromolecular ion has been saturated with surfactant molecules, a noticeable fraction of surfactant ions is expelled from the polyelectrolyte complex, and the vacant sites are occupied by inorganic counterions. This structural transition was discussed within the framework of the theory of coil-globule conformational transition. Schematic representation of pretransition and posttransition states of the polyelectrolyte-surfactant associates was advanced

Crystal structure of (2E,4E)-5-[bis(2-hydroxyethyl)amino]-1-(4-chlorophenyl)-5-phenylpenta-2,4-dien-1-one

In the title compound, C21H22ClNO3, the pentadiene unit is nearly planar [maximum deviation = 0.023 (1) Å], but the carbonyl O atom deviates significantly [by 0.304 (1) Å] from its mean plane, which is twisted with respect to the phenyl and chlorobenzene rings by 71.34 (13) and 46.40 (13)°, respectively. In the crystal, inversion-related molecules are linked by two pairs of O—H...O hydrogen bonds, forming chains propagating along [01-1], enclosing R22(16) and R22(22) ring motifs. The chains are linked via C—H...O hydrogen bonds and C—H...π interactions into a three-dimensional supramolecular architecture

Clinical observation of a combination of diffuse alveolar-septal pulmonary lesion and amyloid cardiomyopathy in systemic AL-amyloidosis in the elderly

A rare observation of systemic AL-amyloidosis with a debut in old age, accompanied by diffuse alveolar-septal lesion of the lungs and me-diastinal lymphadenopathy in combination with amyloid cardiomyopathy in the absence of pathology of kidney and liver function. © 2018 Media Sphera Publishing Group. All rights reserved