Реокинетическое исследование процесса каталитического отверждения олигодиенуретанового форполимера глицерином в условиях избытка изоцианатных групп

For the first time the results of a rheokinetic study on the interaction of an oligodienuerethane prepolymer with glycerol under excessive content of isocyanate groups [NCO/OH = 1.5 (mol/mol)] are presented. It was found that, when conversion degree х ≈ 30 %, the interaction of isocyanate and hydroxyl groups is governed by the first order equation with adiabatic self-acceleration. Then (at х > 30 %) the curing process is described by the second order equation. A specific feature of the studied interactions is that, while temperature increases to 50 ° C, the role of the curing catalysts at the final stage is played by urethane and allophanate groups.Впервые представлены результаты реокинетических исследований процесса взаимодействия олигодиенуретанового форполимера с глицерином при избыточном содержании изоцианатных групп ( NCO / OH = 1.5 (моль / моль)). Установлено, что до степени превращения х ≈ 30% взаимодействие изоцианатных и гидроксильных групп подчиняется уравнению первого порядка с адиабатическим автоускорением, затем (при х > 30 %) процесс отверждения описывается уравнением второго порядка. Выявленной спецификой изученных взаимодействий является то, что с увеличением температуры до 50ºС роль катализаторов отверждения на завершающем этапе выполняют уретановые и аллофанатные группы

Bazovye cennosti nositelej russkoj kul'tury

The dictionary includes 68 values and anti-values selected as a result of experiments in the study of the life values of Russians. The book presents the basic values of modern Russian culture

FEATURES OF LOCAL IMMUNITY IN PATIENTS WITH OROPHARYNGEAL CANCER

Background. Oropharyngeal cancer is the second most frequent cancer among patients with head and neck tumors in the Russian Federation. Patients usually seek medical assistance in the late stages of the disease (stages III–IV). The mortality rate in such patients during the first year after treatment varies from 30 % to 40 %. This makes it necessary to improve the methods of its diagnosis and treatment. Modern laboratory techniques allow predicting patient’s condition before and during the course of treatment; they were implemented into clinical practice for successful treatment correction. An important role is given to assessing the practical experience of related medical institutions.Objective: to develop an algorithm for the diagnosis and treatment of patients with oropharyngeal cancer using the experience of medical institutions dealing with these patients. We explored the experience of the Rostov Research Institute of Oncology and the Republican Specialized Scientific and Practical Medical Center of Oncology and Radiology of the Ministry of Health of the Republic of Uzbekistan.Materials and methods. The study included 40 patients with oropharyngeal cancer who received treatment in the departments of head and neck tumors of the Rostov and Uzbek Oncology Institutes between 2007 and 2014. Twenty-five patients had stage III (T1–3N0–1) oropharyngeal cancer, seven patients were diagnosed with stage IV (T4N0–1) cancer, and eight patients had a widespread relapse. Before admission to the hospital for surgery, all patients received neoadjuvant radiation therapy (40 Gy). The surgeries included radical removal of the primary tumor; patients with cervical metastases underwent simultaneous cervical lymph node dissection (levels IB, IIA–B, III, and VA). Samples of tumor tissues and pertumoral tissues were collected during the surgery. They were homogenized and used for the assessment of the levels of pro- and antiinflammatory cytokines: interleukins (IL) 1β, 6, 8, 10; IL-1 receptor antagonist; interferons (IF) α, and γ; tumor necrosis factor (TNF) α, and secretory immunoglobulin А. Results. Among newly diagnosed patients without regional metastases, the level of proinflammatory cytokines was significantly higher in the tumor tissue compared the peritumoral tissue. Patients with regional metastases had similar differences. In patients with relapses, such difference was observed only for interleukin-6. It should be mentioned that patients with relapses (unlike the participants from the two remaining groups) usually have no difference in the levels of IL-1β, IL-6, and IL-8 between tumor and peritumoral tissues. This may indicate the transformation of visually non-malignant tissue into the malignant one in terms of its immunological characteristics, which is likely to reflect the loss of ability to limit the proliferative potential. In the peritumoral tissue, the levels of tumor necrosis factor α and interleukin 1β were higher in patients with relapses than in newly diagnosed patients without regional metastases. No difference in the level of secretory immoglobulin A between the tumor and peritumoral tissue was observed among patients with or without metastases, whereas patients with relapses were found to have higher levels of secretory immoglobulin A in the tumor tissue compared to the peritumoral tissue. In these patients, the level of secretory immoglobulin A in the tumor tissue was significantly higher than that in patients with metastases who demonstrated its minimal concentrations, which probably indicates the inhibition of its local synthesis. In the peritumoral tissue, this parameter did not vary across the groups. Conclusions. 1. Both clinical data and immunological parameters should be evaluated to supplement the objective assessment of the status of patients with oropharyngeal cancer. 2. The increasing level of pro-inflammatory cytokines in the tumor tissue promotes its progression and dissemination, which may be caused either by their production by tumor cells or by the local inflammatory process; the levels of cytokines in the tumor tissue exceed their levels in the peritumoral tissue. 3. The level of secretory immoglobulin A is minimal in the tissue of the metastatic tumor and maximal in the tissue of the recurrent tumor. However, the differences failed to reach statistical significance