Electrical conductivity for strongly correlated and hybridized Hubbard band

The magnetic and electrical transport properties of strongły correlated Hubbard band (f-band) hybridizing with the non-correlated conduction band (c-band) was studied. The many-body modeł Hamiltonian was treated within the modified alloy analogy scheme and the resulting one-body problem was solved with the use of coherent potential approximation. Within the Kubo-- Greenwood formalism the dc electrical conductivity for bcc magnetic system was calculated and its variation with temperature and number of electrons was examined for different values of the Coulomb and hybridization (V) coupling constants. We found that the effect of strong correlations and hybridization on the conductivity is similar to that produced by the scattering due to the S—f interaction (spin disorder resistivity)

First-principles modeling of the polycyclic aromatic hydrocarbons reduction

Density functional theory modelling of the reduction of realistic nanographene molecules (C42H18, C48H18 and C60H24) by molecular hydrogen evidences for the presence of limits in the hydrogenation process. These limits caused the contentions between three-fold symmetry of polycyclic aromatic hydrocarbon molecules and two-fold symmetry of adsorbed hydrogen pairs. Increase of the binding energy between nanographenes during reduction is also discussed as possible cause of the experimentally observed limited hydrogenation of studied nanographenes.Comment: 18 pages, 7 figures, accepted to J. Phys. Chem.

Features and characteristics of artificial intelligence systems

Artificial intelligence refers to the field of informatics, one of the tasks of which is to simulate human intelligence in an artificial way - with the help of a computer

The Growth and Development of Raspberry Cultivars in the Condition of Uzbekistan

In the article during the growing season the occurence of phenological phases, the buds formation, buds opening, the beginning of flowering, full flowering and the duration and the end of flowering, the time of flowering and the condition of the plants of the raspberry cultivars grown in Uzbekistan are evaluated in points. The results of research to study the beginning of fruit ripening, full ripening, the differences and quality indicators of fruits, the average and maximum weight of the fruit, acidity and sugar content of the fruit are given. Raspberry cultivars with high yields, depending on the ripening period of the fruit, are also recommended herei

Results of surgical treatment of destructive pancreatitis

Based on a retrospective analysis of the methods of surgical correction of ¬various clinical and morphological forms of pancreatic necrosis, the best options for tactics and surgical techniques for this pathology are proposed

Influence of hydrochemical indicators on the age and density of bivalve molluscs, spread in the lower reaches of the Zarafshan river

Hydrochemical parameters of water in ecosystems of Gijdivan district of Bukhara region: O2 content 4,9 ± 0,5 mg / l, Cl2 312 ± 14 mg / l, mineralization - 992-1402 mg / l and oil products about 0,6-0,8 mg / l, it turned out that the amount of these elements in the water exceeds the permissible norm. The following conclusions were made on the basis of the study of the status of the species listed in the “Red Book” in aquatic ecosystems of the lower reaches of the Zarafshan river. We found that the population of the species Colletopterum and Corbicula in the village of Sultanabad in the Navoi region is a growing population, while the population of the species Colletopterum and Corbicula in the Gijduvan region of the Bukhara region is decreasing

Нормотермическая аутоперфузия сердечно‑легочного комплекса ex vivo: оценка функционального статуса и метаболизма

Objective: to carry out a comparative study of the efficacy of a 6-hour normothermic ex vivo heart and lung autoperfusion and cold cardioplegia using Bretschneider’s solution (Custodiol®, Germany).Materials and methods. Landrace pigs weighing 50 ± 5 kg at the age of 4–5 months (n = 10) were used as a model for a series of acute experiments. In the experimental group (n = 5), the cardiopulmonary complex was conditioned by autoperfusion for 6 hours. In the control group, the heart pumping function was restored after 6-hour cold cardioplegia using Bretschneider’s solution. The efficiency of graft preservation was assessed by measuring hemodynamic parameters, myocardial contractile function, and myocardial oxygen consumption.Results. After reperfusion and repeated isolation of the working cardiopulmonary complex, cardiac output was 0.63 [0.37; 0.8] L/min and 0.37 [0.23; 0.37] L/min in the experimental and control groups, respectively (p < 0.05). Indicators – global left ventricular stroke work index and preload recruitable stroke work – were significantly higher in the experimental group (p < 0.05).Conclusion. Normothermic autoperfusion is significantly more effective in preserving the morphofunctional status of a donor heart than static cold storage with Bretschneider solution for 6 hours.Цель: провести сравнительное исследование эффективности 6-часовой нормотермической аутоперфузии сердечного трансплантата ex vivo и фармакохолодовой консервации раствором Bretschneider (Custodiol®, Германия).Материалы и методы. В качестве модели для проведения серии острых экспериментов были использованы свиньи породы ландрас весом 50 ± 5 кг в возрасте 4–5 месяцев (n = 10). В экспериментальной группе (n = 5) кондиционирование сердечно-легочного комплекса проводили методом аутоперфузии в течение 6 часов. В контрольной группе восстановление насосной функции сердца выполняли после 6-часовой фармакохолодовой консервации раствором Bretschneider. Оценку эффективности консервации трансплантата проводили путем измерения параметров гемодинамики, сократительной функции миокарда, потребления миокардом кислорода.Результаты. После реперфузии и повторной изоляции работающего сердечно-легочного комплекса сердечный выброс составил 0,63 [0,37; 0,8] л/мин и 0,37 [0,23; 0,37] л/мин в экспериментальной и контрольной группах соответственно (р < 0,05). Показатели – глобальная ударная работа левого желудочка и рекрутируемая преднагрузкой ударная работа сердца – были значительно выше в экспериментальной группе (р < 0,05).Заключение. В ходе проведенного исследования было показано значительное преимущество нормотермической аутоперфузии в сохранении морфофункционального статуса донорского сердца по сравнению со статической фармакохолодовой консервацией раствором Bretschneider в течение 6 часов