Further Remarks on Extra Roots of Rayleigh Equation and Somigliana Waves

The extra roots of the Rayleigh equation for an elastichalfspace contribute to the solution only for large enough values of thePoisson coefficient (a > 0.309). One of them corresponds to leaking modeswith the phase velocity less than the velocity of the longitudinal wave.A similar wave with distinct dispersion may exists in the case where anelastic halfspace is covered by a thin layer with lower velocities of elasticwaves. The thickness of a layer should be not too small in comparisonwith the wave length

Use of Glauconite in Potato Cultivation Technology

In intensive technologies of cultivation of potatoes, the need for trace elements is increasing. The concentration of trace elements in plants is very small, but the importance of these elements in biochemical processes is difficult to overestimate. The deficiency of trace elements is the root cause of many functional disorders. Trace elements in plants are part of enzymes, stimulate and accelerate plant development, increase resistance to adverse environmental conditions, etc. Also, with their shortage, crop productivity decreases. The use of natural minerals, such as glauconite, containing trace elements, allows improving comprehensive nutrition and increase productivity. Getting early production of high quality potatoes in the summer is important and relevant in the modern world. The use of glauconite in the conditions of the Moscow region, along with fertilizers and irrigation, allows obtaining high-quality products and increasing productivity by 6.3... 29.0%

Determination of Fluorescence Polarization and Absorption Anisotropy in Molecular Complexes Having Threefold Rotational Symmetry

The current work concerns investigation of the polarization properties of complex molecular ensembles exhibiting threefold (C3) rotational symmetry, particularly with regard to the interplay between their structure and dynamics of internal energy transfer. We assume that the molecules or chromophores in such complexes possess strongly overlapped spectra both for absorption and fluorescence. Such trimeric structures are widely found in biological preparations, as for example the trimer of C-phycocyanin (C-PC). Higher order aggregates, e.g. hex-amers and three-hexamer rods, are also investigated and compared with the trimer case. The theory addresses both steady-state and 8-pulse excitation and establishes some links between them. Monochromophoric, bichro-mophoric and trichromophoric molecular complexes are individually examined. For steady-state excitation, analytical formulas are reported for the degree of fluorescence polarization and absorption anisotropy. It is shown that the polarization is dependent on the chromophore inclination relative to the symmetry axis, the relative efficiencies of absorption and fluorescence by chromophores of different spectral types, and the rates of energy equilibration. To assess the validity of the theory, it has been applied to C-PC aggregates. Here it was found that different C-PC aggregates provide practically identical polarization response. For S-pulse excitation we give analytical formulas for determination of the fluorescence depolarization, and also the depolarization associated with absorption recovery, both for a monochromophoric trimer and some particular cases of bichromophoric trimer. More complicated systems are analyzed by computer modeling. Thus it transpires that the initial polarization anisotropy r(t = 0) takes the value 0.4 for all considered aggregates; the long-time limit r(t →∞) has about the same value as is associated with steady-state excitation. We also show that with steady-state excitation the degree of fluorescence polarization is practically equal for various C3 aggregates of C-PC, and that the major factor determining the polarization is the chromophore orientation relative to the symmetry axis

Crustal structure below Popocat\'epetl Volcano (Mexico) from analysis of Rayleigh waves

An array of ten broadband stations was installed on the Popocat\'epetl volcano (Mexico) for five months between October 2002 and February 2003. 26 regional and teleseismic earthquakes were selected and filtered in the frequency time domain to extract the fundamental mode of the Rayleigh wave. The average dispersion curve was obtained in two steps. Firstly, phase velocities were measured in the period range [2-50] s from the phase difference between pairs of stations, using Wiener filtering. Secondly, the average dispersion curve was calculated by combining observations from all events in order to reduce diffraction effects. The inversion of the mean phase velocity yielded a crustal model for the volcano which is consistent with previous models of the Mexican Volcanic Belt. The overall crustal structure beneath Popocat\'epetl is therefore not different from the surrounding area, and the velocities in the lower crust are confirmed to be relatively low. Lateral variations of the structure were also investigated by dividing the network into four parts and by applying the same procedure to each sub-array. No well-defined anomalies appeared for the two sub-arrays for which it was possible to measure a dispersion curve. However, dispersion curves associated with individual events reveal important diffraction for 6 s to 12 s periods which could correspond to strong lateral variations at 5 to 10 km depth

Charlson comorbidity index in predicting deaths in COVID-19 patients

Aim. To assess the clinical performance and factors associated with inhospital mortality in patients with coronavirus disease 2019 (COVID-19).Material and methods. Our results are based on data from hospital charts of inpatients hospitalized in the Asinovskaya District Hospital in the period from March 11, 2020 to December 31, 2020, with a verified COVID-19 by polymerase chain reaction. The study included 151 patients, the median age of which was 66,2 (50- 92) years (women, 91; 60,3%). The study endpoints were following hospitalization outcomes: discharge or death. Depending on the outcomes, the patients were divided into 2 groups: the 1st group included 138 patients (survivors), while the 2nd one included 13 patients (death). To objectify the severity of multimorbidity status, the Charlson comorbidity index was used. The final value was estimated taking into account the patient age by summing the points assigned to a certain nosological entity using a calculator table.Results. Hypertension was recorded in the majority of patients — 79,5%, chronic kidney disease — in 61,1%. The prevalence of type 2 diabetes and coronary artery disease was high — 31,8% each. Prior myocardial infarction was diagnosed in 11,3% of cases. The prevalence of percutaneous coronary intervention and coronary bypass surgery was 5,3% and 3,3%, respectively. Stroke was detected in 9,3% of participants. Prior chronic pulmonary pathologies in COVID-19 patients were rare (asthma — 3,3%, chronic obstructive pulmonary disease — 2,0%). In order to predict the death risk in COVID-19 patients, a logistic regression analysis was performed, which showed that age and Charlson comorbidity index were the most significant predictors.Conclusion. Independent factors of inhospital mortality were age and Charlson’s comorbidity index. The risk assessment model will allow clinicians to identify patients with a poor prognosis at an earlier disease stage, thereby reducing mortality by implementing more effective COVID-19 treatment strategies in conditions with limited medical resources

Risk factors for heart failure in patients with COVID-19

Aim. To establish risk factors for heart failure (HF) in patients with coronavirus disease 2019 (COVID-19).Material and methods. Medical records of 151 patients treated in an infectious disease hospital from November 3, 2020 to February 2, 2021 with a confirmed diagnosis of COVID-19 were retrospectively selected. The collection of clinical, history and laboratory data were carried out by analyzing electronic medical records. We analyzed information on age, sex, body mass index, smoking, and comorbidities. Following laboratory studies were analyzed: complete blood count, biochemical blood tests, coagulation profile, acute phase proteins (C-reactive protein (CRP), ferritin, lactate dehydrogenase (LDH)), procalcitonin. The diagnosis of HF was confirmed by clinical performance, echocardiography, and elevated levels of the N-terminal pro-brain natriuretic peptide (NT-proBNP). The risk of HF was taken as the endpoint of the study.Results. The studied sample of patients was divided into two groups depending on HF: the 1st group included 46 patients with HF, the 2nd group — 105 patients without HF. The median age was 66,2 (50-92) years (women, 91 (60,3%)). Laboratory indicators, such as the levels of CRP, LDH, procalcitonin, creatinine, bilirubin, differed significantly from each other, and the median values were higher in patients with HF. The neutrophil-to-lymphocyte ratio (NLR) showed significant intergroup differences: in the group of patients with HF, the median was 4,97% vs 3,62% (p=0,011) in the group of patients without HF. There were following most significant predictors increasing the HF risk: age ≥66 years (odds ratio, 8,038, p<0,001), procalcitonin level, which increases the HF risk in patients by 3,8 times (p><0,001), NLR ≥4,11% (p=0,010), thrombocytopenia ≤220×109/l (p=0,010), history of chronic kidney disease (CKD) (p=0,018). Conclusion. The following predictors of HF were established: age ≥66 years, procalcitonin ≥0,09 ng/ml, NLR ≥4,11%, thrombocytopenia ≤220×109/l, history of CKD, LDH ≥685 U/l and creatinine ≥102 µmol/l, international normalized ratio ≥1,19, QTc interval ≥407,5 ms, bilirubin ≤10,7 µmol/l. It is worth noting that the best accuracy values are demonstrated by the Random Forest algorithm (88,5% on the validation set), but the mathematical model of the neural network turned out to be the most sensitive (90,0% on the validation set). Keywords: novel coronavirus infection, heart failure, prognosis>˂0,001), procalcitonin level, which increases the HF risk in patients by 3,8 times (p˂0,001), NLR ≥4,11% (p=0,010), thrombocytopenia ≤220×109/l (p=0,010), history of chronic kidney disease (CKD) (p=0,018).Conclusion. The following predictors of HF were established: age ≥66 years, procalcitonin ≥0,09 ng/ml, NLR ≥4,11%, thrombocytopenia ≤220×109/l, history of CKD, LDH ≥685 U/l and creatinine ≥102 µmol/l, international normalized ratio ≥1,19, QTc interval ≥407,5 ms, bilirubin ≤10,7 µmol/l. It is worth noting that the best accuracy values are demonstrated by the Random Forest algorithm (88,5% on the validation set), but the mathematical model of the neural network turned out to be the most sensitive (90,0% on the validation set)

THERAPEUTIC EQUIVALENCE OF ORIGINAL CLOPIDOGREL (PLAVIX) AND ITS GENERIC (EGITROMB). RESULTS OF COMPARATIVE RANDOMIZED CROSS-OVER BLIND STUDY

Aim. To study therapeutic equivalence (efficacy, safety and tolerability) of original clopidogrel (Plavix) and its generic (Egitromb) in patients of high cardiovascular risk. Material and methods. Thirty one patients with coronary heart disease and indications for clopidogrel therapy were involved into the randomized cross-over blind study. Half of the patients received original clopidogrel (75 mg daily) during the first 2 weeks and then they received generic clopidogrel in the same dose during next 2 weeks. Another half of the patients received the drugs in reverse order. Antiplatelet activity of Plavix and Egitromb was estimated by effects on ADP-induced platelet aggregation initially and after 2 weeks of treatment with each drug. Study blinding was provided by the following approach: doctors of cardiology clinic performed clinical monitoring and drug distribution; coded blood samples for platelet aggregation assessment were studied in independent laboratory of thrombosis; statistical data analysis was performed by biostatistics expert in other research center. Results. 2-week therapy with each drug led to a significant decrease of ADP-induced platelet aggregation which remained low after switching from original drug to generic and vice versa. Aggregation dynamics did not depend on the first administered drug. There were no significant differences between aggregation changes as a result of treatment with original or generic drug. No one adverse event was observed in association with both drugs therapy. Conclusion. Generic drug Egitromb (Egis, Hungary) and original clopidogrel Plavix (Sanofi-Aventis, France) have equivalent antiplatelet effect

Унифицированная модель расчетов производительности технических средств при реализации транспортных и транспортно­технологических операций

Productivity is one of the important performance indicators of transport and transport-technological vehicles. The authors confirmed the necessity to unify this indicator calculations for an extensive range of agricultural goods and extensive works on their movement. (Research purpose) To develop universal interconnected stages of detecting the operational productivity of transport and transport-technological vehicles when performing mechanized work in crop production. (Materials and methods) The values of operational performance were determined based on the analysis of norm-forming factors and statistical processing. A systematic approach was used to identifying individual elements of the cargo transportation cycle. The authors studied each of the methodological approaches and the mathematical tools used to calculate the performance indicators of various technical devices. (Results and discussion) After a step-by-step modeling of transport and transport-technological processes, a unified formula of the target function (optimality criterion) was obtained. Having implemented a more convenient calculation algorithm and having transformed the mathematical apparatus, the authors obtained the vehicle production rates for the transportation of mineral fertilizers to the place of their application. (Conclusions) The authors implemented a detailed mathematical description of the transport and transport-technological process stages. They identified the functional relationships between operational parameters and production and agrolandscape conditions.  A universal algorithm was developed making it possible to determine the values of the operational performance for transport and transport-technological vehicles. The authors determined the values of the coefficient enabling the unification and comparison of the algorithm for identifying the production rates for transport and transport-technological work. It was found out that with an increase in the length of transportation from 3 to 54 kilometers, this coefficient increases 3.8 times. This variation was explained by an increase in the purely transport phase of the process.Производительность – один из важных эксплуатационных показателей транспортных и транспортно-технологических средств. Подтвердили необходимость унифицировать расчеты этого показателя на фоне обширной номенклатуры сельскохозяйственных грузов и большого количества работ по их перемещению. (Цель исследования) Разработать универсальные взаимосвязанные этапы определения эксплуатационной производительности транспортных и транспортно-технологических средств при реализации механизированных работ в растениеводстве. (Материалы и методы) Определили значения эксплуатационной производительности посредством анализа нормообразующих факторов и статистической обработки. Использовали системный подход к определению отдельных элементов цикла транспортировки грузов. Изучили каждый из методических подходов и применяемые математические аппараты для определения производительности технических средств различных типов. (Результаты и обсуждение) После поэтапного моделирования реализации транспортных и транспортно-технологических процессов получили унифицированную формулу целевой функции (критерия оптимальности). В результате реализации более удобного алгоритма расчета и преобразования математического аппарата вычислили значения норм выработки для транспортных средств при транспортировке минеральных удобрений к месту их внесения. (Выводы) Провели детальное математическое описание этапов реализации транспортного и транспортно-технологического процесса. Определили функциональные зависимости между эксплуатационными параметрами и производственными и агроландшафтными условиями. Разработали универсальный алгоритм, для расчета значения эксплуатационной производительности транспортных и транспортно-технологических средств. Определили значения коэффициента, позволяющего унифицировать и сопоставить алгоритм вычисления норм выработки на транспортные и транспортно-технологические работы. Выявили, что с увеличением длины транспортировки от 3 до 54 километров этот коэффициент повышается 3,8 раза. Данное варьирование объяснили ростом чисто транспортной фазы выполнения процесса.

Оптимальное соотношение основных механизированных работ при прямоточном внесений удобрений

Use of transport and technological means is carried out according to the direct-flow scheme and includes stage-by-stage performance as the main standard-setting operations (fertilizers transportation, movement and their distribution across a field), and auxiliary (return from a field and loading of fertilizers). The method of comparison of main types of operations at fertilizers application is given. An estimation criterion is a ratio of cargo movements on a road and across a field, proportionality coefficient between movement of freight and a fertilizers distribution area across the field. These indicators depend on transportation distances and doses of fertilizers application, and also on technology factor that is freight moving frequency across the field. The last characteristic is taken as the optimized parameter. An extremum of this indicator was searched due to a classical method. Optimum values of estimated indicators with the accounting of a variation of a ratio of load capacity and operating width of technical means are received. Concrete combinations of transportation distances and doses of fertilizers application are specified. The authors defined conditions of effective use of tractor and perspective automobile transport and technological means. They recommended to use the automeans allowing to change operating width. Realization of the stated methodological approach will make it possible to select an optimum ratio of the mechanized operations at direct-flow fertilizers application, to exclude additional cargo movements across the field, to cut fuel consumption, to increase productivity. Productivity of transport and technological means increases by 2.0; 1.3 and 1.15 times respectively to length of furrow 3; 9 and 27 km at fertilizers application by a dose of 0.06 kg per sq.m.Использование транспортно-технологических средств осуществляется по прямоточной схеме и включает поэтапное выполнение как основных нормообразующих работ (перевозку удобрений, перемещение и распределение их по полю), так и вспомогательных (возвращение средств с поля и погрузку удобрений). Приведен метод сопоставления основных видов работ при внесении удобрений. В качестве оценочных критериев приняты соотношение грузоперемещений по дороге и по полю, коэффициент пропорциональности между перемещением груза по полю и площадью распределения удобрений. Эти показатели зависят от расстояний транспортировки и доз внесения удобрений, а также от технологического фактора - плотности перемещений груза по полю. Последняя характеристика принята за оптимизируемый параметр. Поиск экстремума этого показателя проводили классическим методом. Получены оптимальные значения оценочных показателей с учeтом варьирования соотношения грузовместимости и ширины захвата технических средств. Указаны конкретные сочетания расстояний перевозки и доз внесения удобрений. Определены условия эффективного использования тракторных и перспективных автомобильных транспортно-технологических средств. Рекомендовано использовать автосредства, позволяющие изменять ширину захвата. Реализация изложенного методологического подхода к выбору оптимального соотношения механизированных работ при прямоточном внесении удобрений позволит исключить дополнительные грузоперемещения по полю, снизить расход топлива, повысить производительность. Показали, что производительность транспортно-технологических средств возрастает в 2,0; 1,3 и 1,15 раза соответственно для длины гона 3; 9 и 27 км при внесении удобрений дозой 0,06 кг/кв.м