Ultrasonic Vibroacoustic Processes, Excited By Heating By Impulse Currents of Metals

When passing impulse currents through a conductor, powerful vibro-acoustic oscillations are generated in it. The parameters of these oscillations are easy to control. Changing the duty cycle of pulses allows for such equipment as welding with the allocation of a large amount of heat, and regimes of controlled cooling and ultrasonic quality control of the welded joint. Keywords: welding, vibration, pulse current, diagnostics, ultrasoun

Analysis of the Relationships for the Vibrational Response to the Excitation of Vibro-acoustic Processes in Conductors from the Action of a Pulsed Current

Evaluation of the mechanisms of formation of mechanical deformations is of great importance for the practical application of the electroplastic effect. Estimations of the efficiency of conversion of the energy of the electric pulse in the energy of the magnetic field and mechanical oscillations are obtained. Keywords: pulse current, metal, vibroacoustic, magnetic field, vibration sensors

Electroplastic Processing of Titanium Implants

The results of experimental studies of samples of titanium for implants when exposed to pulsed electric currents. Excitation of longitudinal and transverse vibrations to the sample under these influences can be used in their electroplastic processing and introduction into the bone tissue. When exposed to pulses of surface layers of titanium sample are experiencing significant dynamic load. The possibility of increasing amplitudes with decreasing duration of pulses of electric current was shown. This allows to exclude the heating of implants during such impacts. The peculiarities of ponderomotive effects in titanium samples related to its uniqueelectrical and mechanical properties, precluding the practical manifestation of the classic skin-effect and its impact on the generation of oscillatory processes in the moments of passage of the leading and trailing edges of current pulse. Keywords: titanium, implant, vibration, acceleration, magnetic field, skin effect

Кремнеорганические полмерные композиции медицинского назначения

Our scientific research, concerned with the opportunities of the application of some new silicon-based polymers at carrying out stomatologic procedures, is briefly submitted in this article. The results of the comparative tests with the silicon-based polymeric materials and the materials on the basis of the natural rubber are represented, as well as the graphic dependences confirming legitimacy of made conclusions. At the end of the article, there is the list of the scientific literature used as theoretical basisВ статье кратко представлено резуль- таты исследования возможностей при- менения новых силаксановых полимеров при проведении стоматологических процедур. Приведены результаты срав- нительных испытаний силаксановых по- лимерных материалов и материалов на основе натурального каучука, имеются графические зависимости, подтвержда- ющие правомерность сделанных выво- дов

Результаты трансплантации почки пациентам с терминальной почечной недостаточностью, обусловленной аутосомно-доминантным поликистозом почек

Aim. To investigate the renal transplantation results for patients with end-stage renal disease (ESRD) due to autosomal dominant polycystic kidney disease (PKD).Materials and methods. The study included a prospective and retrospective analysis of the kidney transplantation results in 46 patients with ESRD caused by PKD, performed in the period from 2003 to 2018. Two groups of patients were formed. The comparison group consisted of 23 (50%) cases of kidney transplantation in patients whose polycystic-changed kidneys were preserved at the time of transplantation. The study group included 23 (50%) patients who underwent pretransplantation nephrectomy of native kidneys for clinical indications or to prepare for the waiting list. During the study, an algorithm of examination and surgical preparation for inclusion patients with PKD in the waiting list for kidney transplantation was developed and actively used.Results. The mean follow up period of patients who underwent pretransplantation nephrectomy was 3.6 ± 2.5 years, patients with preserved native kidneys - 5.3 ± 3.08 years (p > 0.05). Periodic pain in the lumbar region disturbed 12 (52.2%) patients with preserved polycystic-changed kidneys. The frequency of episodes of leukocyturia, bacteriuria and(or) hematuria significantly differed and amounted to 0.27 ± 0.35 cases per year in the study group, 1.49 ± 0.54 (p < 0.05) in the comparison group. Posttransplant nephrectomy of polycystic-changed kidneys at different times after transplantation was required in 5 (21.7%) patients. Five-year graft survival in the study group was 87.5%, in the comparison group - 76.1%. Among the patients of the comparison group, 76.4% of transplants lost their function after 10 years. The 5 and 10-year survival rates of patients with preserved native kidneys were 90.5% and 80%, respectively. In particular, there was one fatal outcome due to sepsis on the background of infection with cysts of preserved polycystic kidney. There were no deaths in the study group.Conclusion. Among patients whom polycystic-changed kidneys removed, there is a more favorable course of the post-transplant period due to the low frequency of infectious complications. More than 60% of patients with PKD need to perform nephrectomy of native kidneys during life for various reasons, including more than 21,7% need it after kidney transplantation due to complications during immunosuppressive therapy. Reasonable assessment of the polycystic kidneys and timely pretransplantation nephrectomy are an integral part of the preparation and management of the waiting list for transplantation of a patient with PKD.Цель. Целью данного исследования явилось изучение результатов трансплантации почки пациентам с терминальной почечной недостаточностью (тХПН), обусловленной аутосомно-доминантным поликистозом почек (АДПП).Материалы и методы. В ходе исследования был проведен проспективный и ретроспективный анализ результатов трансплантаций почки 46 больным с тХПН, обусловленной АДПП, выполненных в период с 2003-го по 2018 год. Сформировано две группы пациентов. Группа сравнения составлена из 23 (50%) случаев пересадки почки больным, у которых поликистозно-измененные почки (ПКП) на момент трансплантации были сохранены. Исследуемая группа включала 23 (50%) пациента, которым по клиническим показаниям или с целью подготовки в лист ожидания была выполнена предтрансплантационная нефрэктомия нативных почек. В ходе исследования разработан и активно применялся алгоритм обследования и хирургической подготовки к включению в лист ожидания пересадки почки больных с АДПП.Результаты исследования. Средний срок наблюдения пациентов, перенесших предтрансплантационную нефрэктомию, составил 3,6 ± 2,5 года, больных с сохраненными нативными почками - 5,3 ± 3,08 года (р > 0,05). Периодические боли в поясничной области беспокоили 12 (52,2%) пациентов с сохраненными ПКП. Частота эпизодов лейкоцитурии, бактериурии и(или) гематурии значимо отличалась и составила в исследуемой группе 0,27 ± 0,35 случая в год, в группе сравнения - 1,49 ± 0,54 (р < 0,05). Посттрансплантационная нефрэктомия ПКП в различные сроки после трансплантации потребовалась 5 (21,7%) пациентам. Пятилетняя выживаемость трансплантатов в исследуемой группе составила 87,5%, в группе сравнения - 76,1%. Среди больных группы сравнения через 10 лет функцию утратили 76,4% трансплантатов; 5- и 10-летняя выживаемость пациентов с сохраненными нативными почками составила 90,5% и 80% соответственно, в том числе имел место один летальный исход, обусловленный сепсисом на фоне инфицирования кист сохраненных ПКП. В исследуемой группе летальных исходов не было.Выводы. Среди пациентов, которым удалены ПКП, отмечается более благоприятное течение посттрансплантационного периода за счет низкой частоты инфекционных осложнений. Более 60% больных с АДПП нуждаются в выполнении нефрэктомии нативных почек в течение жизни по различным причинам, в том числе более 21,7% - после пересадки почки в связи с осложнениями на фоне иммуносупрессивной терапии. Разумная оценка состояния ПКП и своевременная предтрансплантационная нефрэктомия являются неотъемлемой частью подготовки и ведения в листе ожидания трансплантации пациента с АДПП

Results of kidney transplantation in patients with end-stage renal failure caused by autosomal dominant polycystic kidney disease

Aim. To investigate the renal transplantation results for patients with end-stage renal disease (ESRD) due to autosomal dominant polycystic kidney disease (PKD).Materials and methods. The study included a prospective and retrospective analysis of the kidney transplantation results in 46 patients with ESRD caused by PKD, performed in the period from 2003 to 2018. Two groups of patients were formed. The comparison group consisted of 23 (50%) cases of kidney transplantation in patients whose polycystic-changed kidneys were preserved at the time of transplantation. The study group included 23 (50%) patients who underwent pretransplantation nephrectomy of native kidneys for clinical indications or to prepare for the waiting list. During the study, an algorithm of examination and surgical preparation for inclusion patients with PKD in the waiting list for kidney transplantation was developed and actively used.Results. The mean follow up period of patients who underwent pretransplantation nephrectomy was 3.6 ± 2.5 years, patients with preserved native kidneys - 5.3 ± 3.08 years (p > 0.05). Periodic pain in the lumbar region disturbed 12 (52.2%) patients with preserved polycystic-changed kidneys. The frequency of episodes of leukocyturia, bacteriuria and(or) hematuria significantly differed and amounted to 0.27 ± 0.35 cases per year in the study group, 1.49 ± 0.54 (p < 0.05) in the comparison group. Posttransplant nephrectomy of polycystic-changed kidneys at different times after transplantation was required in 5 (21.7%) patients. Five-year graft survival in the study group was 87.5%, in the comparison group - 76.1%. Among the patients of the comparison group, 76.4% of transplants lost their function after 10 years. The 5 and 10-year survival rates of patients with preserved native kidneys were 90.5% and 80%, respectively. In particular, there was one fatal outcome due to sepsis on the background of infection with cysts of preserved polycystic kidney. There were no deaths in the study group.Conclusion. Among patients whom polycystic-changed kidneys removed, there is a more favorable course of the post-transplant period due to the low frequency of infectious complications. More than 60% of patients with PKD need to perform nephrectomy of native kidneys during life for various reasons, including more than 21,7% need it after kidney transplantation due to complications during immunosuppressive therapy. Reasonable assessment of the polycystic kidneys and timely pretransplantation nephrectomy are an integral part of the preparation and management of the waiting list for transplantation of a patient with PKD