The nature of lithium perchlorate and gallium chloride salt effect in cycloaddition reactions

Comparing the acceleration effects of (4 + 2)-, (3 + 2)- and (2 + 2)-cycloaddition reactions in the presence of the salts of two types: gallium chloride in inert solvents and lithium perchlorate (LP) in diethyl ether (DE) it was observed that in the presence of GaCl3 the acceleration effect is approximately the same (104 times) for the studied reactions, while in LPDE medium for the same reactions strong increase (up to 104 times), weak increase or even decrease of the rate and equilibrium constants take place even with the common dienophile depending on the nature of the second reagent. it was suggested that the acceleration effect of cycloaddition reactions in the presence of such Lewis acids as aluminum, gallium or boron halides is due to the sharp increase of Π-acceptor properties of dienophiles and therefore increasing energy of orbital interaction, whereas LPDE medium demonstrates strong stabilization of static and/or dynamic polar forms and favors reactions with charge control

Diels-Alder reaction between naphthalene and N-phenylmaleimide under ambient and high pressure conditions

The rate and equilibrium constants for the Diels-Alder reactions between benzene and naphthalene as dienes and tetracyanoethylene, maleic anhydride and N-phenylmaleimide as dienophiles at 25°C were estimated from empirical rule. The highest yield of the adduct was predicted for the reaction of naphthalene with N-phenylmaleimide. The time of adduct formation in 50% yield exceeds 30 years. The use of gallium chloride as a catalyst affords the exo-adduct for seven days at room temperature. The rate ((2±0.5)•10-6 L mol-1 s-1) and equilibrium constants (5±2 L mol-1) of this reaction were determined. Under high pressure conditions (8kbar) reaction occurs with formation of both stereo isomers at 100°C during 80 hours. © ARKAT

Course of COVID-19 in Patients with Inflammatory Bowel Disease: Regional Experience

Aim: to study the course of COVID-19 in patients with inflammatory bowel diseases (IBD) using the example of the region of the Republic of Tatarstan.Material and methods. The study included 101 patients diagnosed with IBD and COVID-19, who were observed in two infectious diseases hospitals in Kazan (Republican Clinical Hospital of the Ministry of Health of the Republic of Tatarstan and City Clinical Hospital No. 7) and on an outpatient basis from April 2020 to March 2022. All patients underwent physical examination, laboratory and instrumental diagnostic methods, including a PCR test for SARSCoV-2. Chest computed tomography was performed in patients with clinical signs of moderate to severe COVID-19.Results. Ulcerative colitis (UC) was diagnosed in 60 (59.4 %) patients, Crohn's disease (CD) — in 41 (40.6 %) patients. The mean age of the patients was 41.0 ± 14.7 years, of which 59 (58.4 %) were men and 42 (41.6 %) were women. A comparative analysis of patients with and without IBD and CT-verified lung disease was carried out. It was found that the development of viral pneumonia was influenced by age over 55 years (39.2 ± 9.7 vs. 46.3 ± 10.6, p < 0.05), increased Body Mass Index (BMI) (23.1 ± 5.35 vs. 30.25 ± 6.17, p < 0.05), hypertension (6 (8.3 %) vs. 8 (27.6 %), p < 0.05), diabetes mellitus (2 (2.7 %) vs. 5 (17.2 %), p < 0.05), the use of corticosteroids in the treatment of IBD (8 (11.1 %) vs. 10 (34.5 %), p < 0.05). In a comparative analysis of patients with IBD and COVID-19 from the SECURE-IBD database and own data, it was found that the average age of patients was comparable (42.7 vs 41.0). At the same time, in our group of male patients, there were slightly more people with DM, increased BMI, and an active course of IBD. The proportion of hospitalized patients was higher. In our cohort, there were fewer patients receiving biological therapy, but more patients on 5-aminosalicylic acid (5-ASA) and systemic corticosteroids. At the same time, lethal outcomes were comparable.Conclusion. In patients with IBD, the development of viral pneumonia was influenced by known risk factors for COVID-19: age over 55 years (p < 0.05, odds ratio (OR) 3.153), increased BMI (p < 0.05, OR 1.667), hypertension  (p < 0.05, OR 2.724), diabetes (p < 0.05, OR 1.489), as well as the use of systemic corticosteroids (p < 0.05, OR 1.5)

Basic properties of the preparation "Loramor" in the complex treatment of purulent-inflammatory diseases of the objective facial region

The article reflects the results of the study of the main properties of the drug "Loramor" in the complex treatment of purulent-inflammatory diseases of the maxillofacial region (МFR) among patients who were treated in the department of maxillofacial surgery of the city medical association of Samarkand. The results of the study prove the effectiveness of the use of the drug "Loramor" in the complex treatment of purulent-inflammatory diseases of the maxillofacial region.В статье отражены результаты исследования основных свойств препарата «Лорамор» в комплексном лечении гнойно-воспалительных заболеваний челюстно-лицевой области среди пациентов,находившихся на лечении в отделении челюстно-лицевой хирургии Самаркандского городского медицинского объединения. Полученные результаты исследования доказывают эффективность использования препарата «Лорамор» в комплексном лечении гнойно-воспалительных заболеваний челюстно-лицевой области

Lattice vibrations of alpha'-NaV2O5

We have measured far infrared reflectance and transmittance spectra as well as Raman scattering spectra of \alpha'-NaV2O5 single crystals for all the principal polarizations. The temperature range above the phase transition temperature T_c=35 K was investigated, mainly. On the basis of this experimental study and of the lattice dynamics calculations we conclude that the symmetry of NaV2O5 in the high temperature phase is described by the centrosymmetric D_{2h}^{13} space group. The assignment of the observed phonons is given. Values of dielectric constants are obtained from the infrared data. Asymmetric shapes of several infrared lines as well as higher order infrared vibrational spectra are discussed. The crystal field energy levels of the 3d electron localized at the V^{4+} site have been calculated in the framework of the exchange charge model using the values of effective charges obtained from the lattice dynamics calculations. According to the results of these calculations, the earlier observed broad optical bands in the region of 1 eV can be interpreted as phonon assisted d-d transitions.Comment: 12 pages, 8 figures, 5 tables; submitted to PR

Identifying patterns of alumni commitment in key strategic relationship programmes

Higher education institutions (HEIs) need to understand their alumni when drawing strategic relationship programmes. This paper aims to identify clusters of alumni based on their commitment relationship and to analyse factors influencing their intention to collaborate with the HEI. The study took place at a Portuguese university, considering a dataset of 1075 of alumni asserting intention to collaborate. First, a cluster analysis was conducted to identify patterns of commitment relationship. Secondly, a logistic regression was run to identify determinants of intention to collaborate. Both techniques revealed the decisive role of HEI commitment in the process. Relationship advantages and positive feelings towards the HEI were also pointed out as important. Alumni asserted recommendations, further training, sharing experiences and giving help as ways to collaborate with HEI. Regression results suggest that sociodemographic variables such as gender, marital status and volunteering are significantly associated with a probability to collaborate. Results also show that affiliation in sororities/fraternities and participation in extracurricular activities are significantly associated with that collaborative intention. The findings provide clues to support strategic relationship programmes based on consistent marketing campaigns, while bringing value to the literature in the European context, where alumni culture requires real insights to evolve.info:eu-repo/semantics/publishedVersio

КИНЕТИКА ПРОЦЕССА ОКИСЛИТЕЛЬНОГО ХЛОРИРОВАНИЯ МЕТАНА

Heterogeneous oxidative chlorination of methane was investigated. The target product is methyl chloride. The investigated terms and conditions of oxychlorination of methane: process temperature 400°C, pressure 0.1-0.9 MPa, catalyst (% weight.): copper chloride (II) 1-8%; potassium chloride 2.5%; lanthanum chloride 1%; carrier - aluminosilicate. Powder X-ray diffractometry and electron microscopy showed that the active catalyst components (CuCl2, KCl, LaCl3) are unevenly distributed on the support surface (α-Al2O3·SiO2) and form agglomerates with a high salt content, including binary chlorides such as KCuCl3, K2CuCl3 or K2CuCl4, hydrates K2CuCl4·2H2O and CuCl2·2H2O and hydroxychlorides Cu3Cl4(OH)2 and Cu2Cl(OH)3. The kinetics of methane oxychlorination was studied in a gradientless reactor at 400°C and pressure 0.1 - 0.9 MPa by varying the partial pressures of the reactants. Analysis of the products was carried out by GC. An equation of the reaction rate including partial pressures of methane, hydrogen chloride and water to the 0.77, 0.01 and 0.64 power, respectively, but of zero order by oxygen and chlorine provides an adequate description of methyl chloride formation rate. Significant influence of water partial pressure is proved for the reaction under consideration.Гетерогенно-каталитическая реакция окислительного хлорирования метана, целевым продуктом которой является хлористый метил, изучена при температуре 400°С и варьировании давления в диапазоне 0.1-0.9 МПа. Методами дифрактометрии и электронной микроскопии показано, что активные компоненты катализатора (CuCl2, KCl, LaCl3) распределяются неравномерно на поверхности носителя (α-Al2O3·SiO2), образуя агломераты с повышенным содержанием солей, в том числе двойных хлоридов, таких как KCuCl3, K2CuCl3 или K2CuCl4, гидрата K2CuCl4·2H2O и гидроксихлоридов состава Cu3Cl4(OH)2 и Cu2Cl(OH)3. Кинетические закономерности изучены в проточном безградиентном по парциальным давлениям реакторе при 400°С методом однофакторного эксперимента при варьировании парциальных давлений реагентов. Анализ продуктов проводили методом газовой хроматографии. Обработкой кинетических данных степенными уравнениями показано, что адекватное описание скорости образования хлористого метила обеспечивает уравнение, в которое входят парциальные давления метана, хлористого водорода и воды в степенях 0.77, 0.01 и 0.64, соответственно, при нулевых порядках по кислороду и хлору

The nature of lithium perchlorate and gallium chloride salt effect in cycloaddition reactions

Comparing the acceleration effects of (4 + 2)-, (3 + 2)- and (2 + 2)-cycloaddition reactions in the presence of the salts of two types: gallium chloride in inert solvents and lithium perchlorate (LP) in diethyl ether (DE) it was observed that in the presence of GaCl3 the acceleration effect is approximately the same (104 times) for the studied reactions, while in LPDE medium for the same reactions strong increase (up to 104 times), weak increase or even decrease of the rate and equilibrium constants take place even with the common dienophile depending on the nature of the second reagent. it was suggested that the acceleration effect of cycloaddition reactions in the presence of such Lewis acids as aluminum, gallium or boron halides is due to the sharp increase of Π-acceptor properties of dienophiles and therefore increasing energy of orbital interaction, whereas LPDE medium demonstrates strong stabilization of static and/or dynamic polar forms and favors reactions with charge control

THE ROLE OF VASCULAR GROWTH FACTORS IN DIABETIC RETINOPATHY AND MACULAR EDEMA DEVELOPMENT

The paper discusses the key role of VEGF and PlGF in the pathogenesis of diabetic retinopathy and macular edema and describes the mechanisms of retinal neoangiogenesis under the influence of these factors. An overview of treatment methods of retinopathy and macular edema is given, with a focus on anti-VEGF therapy. Anti-VEGF drugs are listed and compared, taking account of the results of their clinical trials. For citation: Iskhakova A.G., Zolotarev A.V., Viktorov D.A., Toropovsky A.N., Nikitin A.G. The role of vascular growth factors in diabetic retinopathy and macular edema development. Russian ophthalmological journal. 2018; 11 (2): 62-9. doi: 10.21516/2072-0076-2018-11-2-62-69 (In Russian)

Diels-Alder reaction between naphthalene and N-phenylmaleimide under ambient and high pressure conditions

The rate and equilibrium constants for the Diels-Alder reactions between benzene and naphthalene as dienes and tetracyanoethylene, maleic anhydride and N-phenylmaleimide as dienophiles at 25°C were estimated from empirical rule. The highest yield of the adduct was predicted for the reaction of naphthalene with N-phenylmaleimide. The time of adduct formation in 50% yield exceeds 30 years. The use of gallium chloride as a catalyst affords the exo-adduct for seven days at room temperature. The rate ((2±0.5)•10-6 L mol-1 s-1) and equilibrium constants (5±2 L mol-1) of this reaction were determined. Under high pressure conditions (8kbar) reaction occurs with formation of both stereo isomers at 100°C during 80 hours. © ARKAT