Effects of temperature and concentration factors on the conformational state and reactivity of potassium poly(oxyethylene glycolate)

With the use of pulsed magnetic-field gradient NMR, self-diffusion coefficients of potassium poly(oxyethylene glycolate) macromolecules and solvent molecules (acetone) and the variation in the dimensions of supramolecular structures of potassium poly(oxyethylene glycolate) with temperature and its concentration in acetone are measured. It is discovered that the temperature dependences of change in the rate constants of reactions that proceed during the interaction of potassium poly(oxyethylene glycolate) with 2,4-toluylene diisocyanate do not fit Arrhenius coordinates. © 2010 Pleiades Publishing, Ltd

Immobilization of organic reagents on optically transparent mesoporous polymers and its analytical use

© 2015 Pleiades Publishing, Ltd. Sorption of organic reagents Arsenazo III and 1-(2-pyridylazo)-2-naphthol onto optically transparent mesoporous polymers prepared from macroinitiators and toluene 2,4-diisocyanate was studied. The possibility of preconcentration of organic reagents and their complexation with Cu(II) and Ca(II) ions in the polymer pore voids was demonstrated. Experiments on spectrophotometric analysis using the polymeric support showed that the lower limit of determination was 20 μg mL-1 for Ca(II) and 2 μg mL-1 for Cu(II)

Mössbauer study of structurally ordered iron coordination compounds and polyurethanes crosslinked by them

The structure of a metal-complex system based on ferric chloride and monoethanolamine and the products of interaction of this system with ε-caprolactam and a urethane prepolymer was studied by Mössbauer spectroscopy. It was found that iron ions in the coordination compounds of interest are linked with one another in a chain structure via chloride bridges. The columnar structure of metal complexes, the presence of magnetic ordering in these complexes below 70 K, and the feasibility of formation of metal complexes ordered in the same manner in a flexible-chain polymer matrix containing electron-donating groups were revealed. © Pleiades Publishing, Inc., 2006

Investigation of supramolecular organization of polyetherisocyanatesiloxanes

The characteristics of the supramolecular organization of polyetherisocyanatesiloxanes are inferred from measurements of the temperature dependence of the dielectric loss tangent. It is shown that the mutual influence of macromolecular components on the formation of interpenetrating polymer network depends on the prescription and temperature conditions of synthesis. © 2011 Pleiades Publishing, Ltd

Framed aromatic polyurethanes based on an anionic macroinitiator, 4,4'-diphenylmethane diisocyanate, and 4,4'-dihydroxy-2,2-diphenylpropane: Synthesis and characterization

© 2017, Pleiades Publishing, Ltd. Polyurethanes composed of aromatic components are synthesized using the catalytic effect of potassium alcoholates on the reaction of urethane formation occurring with participation of 4,4'-dihydroxy-2,2-diphenylpropane, 4,4'-diphenylmethane diisocyanate, and polyisocyanate, which is a mixture of 4,4'-diphenylmethane diisocyanate and its branched derivatives. In the case of 4,4'-diphenylmethane diisocyanate, segmented polyurethanes with the predetermined length of the rigid block are formed, while the use of polyisocyanate gives rise to framed aromatic polyurethanes. The use of macroinitiators as carriers of potassium alcoholate groups does not cause microphase separation of flexible and rigid segments

Synthesis and properties of novel polyurethanes based on amino ethers of boric acid for gas separation membranes

© The Royal Society of Chemistry. Herein we present the structural and mechanical properties of polyurethanes synthesized from amino ethers of boric acid for gas separation. The polymers were characterized by light scattering methods, conductivity measurements, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and atomic force microscopy. Additionally, the permeability of ammonia and carbon dioxide, as well as the selectivity for their diffusion and resultant impurity are presented. The results illustrate the steric hindrance, resulting in a branched architecture borate formation, leads to intermolecular complexation which may assist the polymer in ammonia diffusion selectivity

The effect of microporous polymeric support modification on surface and gas transport properties of supported ionic liquid membranes

© 2015 by the authors; licensee MDPI, Basel, Switzerland. Microporous polymers based on anionic macroinitiator and toluene 2,4-diisocyanate were used as a support for 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf2N]) immobilization. The polymeric support was modified by using silica particles associated in oligomeric media, and the influence of the modifier used on the polymeric structure was studied. The supported ionic liquid membranes (SILMs) were tested for He, N2, NH3, H2S, and CO2 gas separation and ideal selectivities were calculated. The high values of ideal selectivity for ammonia-based systems with permanent gases were observed on polymer matrixes immobilized with [bmim][PF6] and [emim][Tf2N]. The modification of SILMs by nanosize silica particles leads to an increase of NH3 separation relatively to CO2 or H2S

Оценка риска осложнений в бариатрической хирургии

Introduction. Surgical treatment of obese patients includes a high risk of complications.Material and methods. The article presents the analysis of the informativeness and reliability of OS-MRS, E. Livingston, P. Turner scores in predicting postoperative complications in patients with overweight and metabolic disorders.Results. According to the study, the OS-MRS score was the most reliable.Введение. Хирургическое лечение пациентов с ожирением несет высокий риск осложнений.Материал и методы. Представлен анализ информативности и достоверности шкал OS-MRS, E. Livingston, P. Turner в прогнозировании послеоперационных осложнений у пациентов с избыточной массой тела и метаболическими нарушениями.Результаты. По данным проведенного исследования, шкала OS-MRS является наиболее достоверной

АТРИОСЕПТОСТОМИЯ С ИМПЛАНТАЦИЕЙ ФЕНЕСТРИРОВАННОГО ОККЛЮДЕРА ПРИ ИДИОПАТИЧЕСКОЙ ЛЕГОЧНОЙ ГИПЕРТЕНЗИИ

Introduction. Pulmonary arterial hypertension (PAH) is a rare disease of unknown etiology, characterized by increased resistance of pulmonary vessels, which leads to right ventriculae heart failure and, eventually, death. At the same time, according to the literature, it has been established that the presence of an atrial septum defect in patients with idiopathic PAH (iPAH), is accompanied by a longer life expectancy, improves its quality and is the prevention of sudden death due to the development of a pulmonary hypertensive crisis. We decided to perform an operation to create an atrial septum communication (ASC) in patients with iPAH.Materials and methods. Clinical cases showed efficiency in creating interatrial septum fenestration by implantation of intentionally fenestrated occluder in patients with PAH.Results. It was in studies revealing that the advantage of this method as compared to others is close good fixation of the device on interatrial baffle which reduces possibility for the device to migrate from fixed position in the heart cavity and to reduce intra-operative complication. After implantation of fenestrated occluder the patients showed significant improvement of life quality: decrement of breathlessness, higher tolerance to physical exertion, less swelling in lower limbs, absence of syncopal condition. Such procedure perhaps prolongs life time.Conclusion. Implantation of fenestrated occluder, modified in intra-operative conditions, can be an adequate method to help patients with iPAH, under conditions of unavailability of special devices in the market. Введение. Легочная артериальная гипертензия (ЛАГ) является прогрессирующим смертельным синдромом, характеризующимся повышенным сопротивлением легочных сосудов, что приводит к правосторонней сердечной недостаточности и в итоге — смерти. Вместе с тем было доказано, что наличие открытого овального окна у больных с идиопатической легочной артериальной гипертензией (иЛАГ) сопровождается большей продолжительностью жизни и значительно более высоким ее качеством. Это является обоснованием исследований по созданию межпредсердного сообщения (МПС) у больных с иЛАГ. Цель создания адекватного МПС — профилактика внезапной смерти вследствие развития легочно-гипертензионного криза.Материалы и методы. На клинических случаях продемонстрирована эффективность cоздания межпредсердного сообщения путем имплантации намеренно фенестрированных окклюдеров пациентам с ЛАГ.Результаты. Установлено, что преимуществом данного метода перед другими является плотная хорошая фиксация устройства на межпредсердной перегородке, что уменьшает возможность миграции устройства из фиксированного положения в полости сердца и интраоперационных осложнений. После имплантации фенестрированного окклюдера у пациентов наблюдалось значительное улучшение качества жизни: снижение одышки, повышение толерантности к физической нагрузке, уменьшение отеков нижних конечностей, отсутствие синкопальных состояний. Данная процедура предположительно способствует увеличению продолжительности жизни.Заключение. Имплантация фенестрированного окклюдера, модифицированного в интраоперационных условиях, может быть адекватным методом помощи пациентам с иЛАГ в условиях недоступности специальных устройств на рынке.

ОПЫТ УСПЕШНОГО ПРИМЕНЕНИЯ ВАКУУМНОЙ ТЕРАПИИ В ЛЕЧЕНИИ НЕСОСТОЯТЕЛЬНОСТИ КУЛЬТИ ЖЕЛУДКА ПОСЛЕ ЛАПАРОСКОПИЧЕСКОЙ ПРОДОЛЬНОЙ РЕЗЕКЦИИ: КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ

Gastric leak is the most dangerous postoperative complication of laparoscopic sleeve gastrectomy. Traditional surgical treatment options and endoscopic stent placement are not always successful. Negative Pressure Wound Therapy (NPWT) has shown itself like a new successful and feasible treatment option for leaks of different etiology after gastro-esophageal surgery.The initial body mass index (BMI) of the patient was 46 and co-morbidity was represented: arterial hypertension, type 2 diabetes and dyslipidemia. NPWT was initiated in 14 days after laparoscopic sleeve gastrectomy. The abdominal part of the system were changed 3 times for14 days. The patient was discharged from the hospital in 14 days after the secondary sutures to the wound. No relevant complications related to the procedure were observed during the course of the vacuum therapy. It combines defect closure, effective drainage and allows doing a periodic inspection of the wound cavity. NPWT is a successful, safety and effective treatment option for the leaks after laparoscopic sleeve gastrectomy Несостоятельность культи желудка является наиболее опасным послеоперационным осложнением лапароскопической продольной резекции желудка. Традиционные варианты хирургического лечения и эндоскопическая установка стентов не всегда успешны. Терапия отрицательным давлением (NPWT) показала, что это новый возможный эффективный метод лечения несостоятельности различной этиологии после операций на желудке и пищеводе.Исходный индекс массы тела пациентки составлял 46 кг/м2 , а сопутствующие заболевания были представлены артериальной гипертензией, сахарным диабетом 2-го типа, дислипидемией. Терапия отрицательным давлением была начата через 14 суток после лапароскопической продольной резекции желудка. В течение 14 дней было произведено 3 смены абдоминальной части системы. Через 14 дней после наложения вторичных швов на рану пациентка была выписана из стационара. За время применения вакуум-терапии не наблюдалось никаких осложнений, связанных с соответствующей методикой. Она сочетает в себе закрытие дефектов и эффективное дренирование, а также позволяет проводить периодический осмотр полости раны. NPWT – успешный, безопасный и эффективный способ лечения несостоятельностей после лапароскопической продольной резекции желудка.