The first experience of a hybrid approach in the surgical treatment of atrial fibrillation

Background: Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with an increased risk of death, progression of heart failure, and the development of cardiogenic thromboemboli. Despite the significant success in the management of AF in the paroxysmal form, the results of the treatment for patients with persistent forms of AF remain unsatisfactory. Though the surgical approach provides higher rates of efficiency regarding the restoration of a sinus rhythm, transmural lesions are not always attainable, as a result, the rate of AF recurrence in the long-term period remains fairly high. It is also impossible to create ablative patterns to the mitral and tricuspid valves during thoracoscopic epicardial ablation, which can cause the development of recurrent AF, perimitral and typical atrial flutter. Therefore, the development of hybrid approaches combining the advantages of catheter and thoracoscopic techniques is an urgent task of contemporary surgical and interventional arrhythmology. Aims: to estimate the immediate results of a hybrid approach in the management of patients with persistent AF. Methods: We report the first experience of a hybrid treatment of patients with persistent AF. 6 patients aged 53-64 years (1 female, 5 males) were included in the study. At the first stage, thoracoscopic epicardial bipolar ablation was performed (modified GALAXY protocol); the second stage (in 3 to 6 months after the thoracoscopic stage) included an intracardiac electrophysiological study with three-dimensional endocardial mapping followed by endocardial ablation. Results: The thoracoscopic stage of the hybrid treatment included ablation according to the box lesion scheme using a bipolar irrigation equipment. No lethal outcomes and severe, life-threatening complications were registered. The duration of the inpatient period was 510 hospital-days. The 2nd stage of the hybrid treatment was limited to intracardiac electrophysiological examination only in 2 patients. In 4 patients, epicardial radiofrequency ablation was complemented by endocardial radiofrequency exposure. In 3 of the 4 patients who underwent endocardial radiofrequency ablation, catheter ablation of the mitral and cavotricuspid isthmus was required because of the induction of perimitral and typical flutter, respectively. After the 2nd stage of the hybrid treatment, at the time of discharge all the patients maintained a stable sinus rhythm. There were no severe complications or lethal outcomes. Conclusion: a hybrid approach in the AF management is a safe and effective method of treatment, which combines the advantages of minimally invasive surgery and endocardial intervention in patients with persistent AF. The technique is safe and has acceptable short-term results

Formation Nanocrystalline Phases of Palladium and Platinum on a Carbon Support in Autoclave Conditions

Методами электронной микроскопии, газовой адсорбции и рентгенографии охарактеризованы продукты разложения комплексных соединений платины и палладия из аммиачно- щелочных растворов в автоклавных условиях при температуре 170 °С. Установлено, что в результате протекающих реакций образуются высокодисперсные порошки платины и палладия. Показана возможность формирования металлических наночастиц платины и палладия на поверхностях различных углеродных носителей в автоклавных условиях. Методом электронной микроскопии исследовано распределение металлических наночастиц на поверхностях углеродных носителейDecomposition products of platinum and palladium in ammonia- alkaline solutions under autoclave conditions at a temperature of 170 °C were characterized by electron microscopy method, gas adsorption and X-ray diffraction. It is established that as a result of thermolysis the fine-dispersed powders of platinum and palladium are formed. The possibility of forming of platinum and palladium metal nanoparticles on the surfaces of various carbon substrates under autoclave conditions is shown. The distribution of metal particles on the surface of carbon substrates were investigated by electron microscopy metho

Formation Nanocrystalline Phases of Palladium and Platinum on a Carbon Support in Autoclave Conditions

Методами электронной микроскопии, газовой адсорбции и рентгенографии охарактеризованы продукты разложения комплексных соединений платины и палладия из аммиачно- щелочных растворов в автоклавных условиях при температуре 170 °С. Установлено, что в результате протекающих реакций образуются высокодисперсные порошки платины и палладия. Показана возможность формирования металлических наночастиц платины и палладия на поверхностях различных углеродных носителей в автоклавных условиях. Методом электронной микроскопии исследовано распределение металлических наночастиц на поверхностях углеродных носителейDecomposition products of platinum and palladium in ammonia- alkaline solutions under autoclave conditions at a temperature of 170 °C were characterized by electron microscopy method, gas adsorption and X-ray diffraction. It is established that as a result of thermolysis the fine-dispersed powders of platinum and palladium are formed. The possibility of forming of platinum and palladium metal nanoparticles on the surfaces of various carbon substrates under autoclave conditions is shown. The distribution of metal particles on the surface of carbon substrates were investigated by electron microscopy metho

Interaction of Rhodium with Chloro-Complexes of Palladium at Elevated Temperatures

Синтезированы порошки высокодисперсного родия моно- и полиблочной структуры. Исследованы процессы укрупнения кристаллитов нанодисперсного родия. Методами электронной просвечивающей микроскопии и рентгенофазового анализа детально изучен процесс укрупнения родиевой черни при 130 и 180 °С. Установлено, что в растворах соляной кислоты наблюдается растворение родия (0), связанное с наличием на его поверхности хемосорбированного кислорода. Впервые показана возможность образования твердых родий- палладиевых растворов замещения при протекании реакции цементацииPowders of superfine rhodium with mono- and polyblock structures were obtained. The processes of coarsening of nanodispersed rhodium crystallites were investigated in detail at 130 and 180 °C. In muriatic solutions, dissolution of metal rhodium was found to occur. It was connected with the presence of chemisorbed oxygen at its surface. The possibility of formation of rhodium-palladium substitutional solid solutions on the electrolytic precipitation was firstly establishe

Distribution and morphology of mud volcanoes and other fluid flow-related lake-bed structures in Lake Baikal, Russia

New high-resolution multibeam bathymetry data recorded in 2009 in the deepest lake in the World, Lake Baikal, Siberia, enabled a better understanding of the morphology of ten known lake-bed structures-the Bolshoy, Malenki, Malyutka and Stari mud volcanoes in the South Baikal Basin, the K1-4 structures in the Selenga delta, and the Novosibirsk and St. Petersburg structures in the Central Baikal Basin-and also the discovery of 29 new lake-bed structures. These new structures are the S1, Tolstiy, mTSG and S2 in the South Baikal Basin, the P1-P4, P6-P19 and K5-K8 in the Selenga delta accommodation zone, and the C1, C3 and C4 edifices in the Central Baikal Basin. In all, 39 positive relief structures were identified and their large-scale distribution mapped. Based on their typical shape, the observation of high-reflectivity areas on side-scan sonar data records, and evidence of feeder channels on subsurface data, these structures can be classified as mud volcanoes. This has already been confirmed in other publications for the Bolshoy, Malenki and K2 structures, by the recovery of mud breccias in sediment cores. Most structures occur on or near faults and have orientations parallel with the major faults and main stress orientations in the basins, suggesting a strong structural control on the formation of the mud volcanoes. Their slopes are generally steeper than 5A degrees, consistent with interpretation as mud cones formed by high-viscosity, stiff mud plugs. Only few structures appear to be characterised by a crater, in which case this apparent crater seems to be formed by the coalescence of several single cones, leaving a depression in the centre. Some structures have a moat, which has probably an erosional origin. Furthermore, three depressions have been found, named P5, P20 and C2, which are suggested to be pockmarks

Формирование наноматериалов на основе цветных и благородных металлов в автоклавных условиях

The physicochemical laws of formation of multicomponent phases containing noble metals in hydrothermal conditions were investigated. Approaches to a purposeful variation of structure and composition of mono-, bi- and polymetallic phases based on non-ferrous and noble metals were realized. Structural, phase and chemical stability of polymetallic nanostructures in some carrier materials was investigatedИсследованы физико-химические закономерности формирования в гидротермальных условиях многокомпонентных фаз, содержащих благородные металлы. Реализованы подходы целенаправленного варьирования структуры и состава моно-, би- и полиметаллических фаз на основе цветных и благородных металлов. Исследована структурная, фазовая и химическая стабильность полиметаллических наноструктур в материале носител