Propagation of an Acoustic Pulse of Finite Amplitude in a Granular Medium

A study of propagation of a wide-band acoustic signal in a granular medium is reported. Experimental data on the propagation of pulses with an amplitude up to 3 MPa and characteristic length about 1 µs through a sample of cobalt-manganese nodules are compared with a computer model of the process. An anomalous sig'rfal absorption in the high-frequency range observed with relatively weak sounding pulses is explained under the assumption of a fractal sample structure on a certain scale. When the signal amplitude increases, the ahsorption assumes a normal power form which is evidence of substance structural changes

ANATOMICO-SURGICAL FOUNDATIONS OF DUODENOJEJUNAL CHANGE AT THE CHRONIC DUODENAL OBSTRUCTION

Anatomic and clinical research of duodenojejunal change in norm, and at the chronic duodenal obstruction, of functional character was realized. Peculiarities of motor-evacuation disorders + were revealed with help of X-ray method and peripheral computed, electrogastroenterography. Sizes, variants of forms of duodenojejunal change in norm, and in pathology were determined with, use of endoscopic method

The Granular Phase Diagram

The kinetic energy distribution function satisfying the Boltzmann equation is studied analytically and numerically for a system of inelastic hard spheres in the case of binary collisions. Analytically, this function is shown to have a similarity form in the simple cases of uniform or steady-state flows. This determines the region of validity of hydrodynamic description. The latter is used to construct the phase diagram of granular systems, and discriminate between clustering instability and inelastic collapse. The molecular dynamics results support analytical results, but also exhibit a novel fluctuational breakdown of mean-field descriptions.Comment: 15 pages, 4 figure

Coefficient of normal restitution of viscous particles and cooling rate of granular gases

We investigate the cooling rate of a gas of inelastically interacting particles. When we assume velocity dependent coefficients of restitution the material cools down slower than with constant restitution. This behavior might have large influence to clustering and structure formation processes.Comment: 3 figures, Phys. Rev. E (in press

РАЗВИТИЕ НАУЧНОГО НАПРАВЛЕНИЯ ПО МИКРОХИРУРГИИ ВНУТРЕННИХ ОРГАНОВ И МАГИСТРАЛЬНЫХ ВЕН В ОРЕНБУРГСКОЙ ГОСУДАРСТВЕННОЙ МЕДИЦИНСКОЙ АКАДЕМИИ

In the article the chronology in the development of the scientific problem on microsurgery of internal organs and main veins are described, the information about departments and authors of investigations is adduced.В статье описана хронология развития научного направления по микрохирургии внутренних органов и магистральных вен в Оренбургской государственной медицинской академии, приведены сведения о кафедрах и авторах исследований.

ОПЫТ ЛЕЧЕНИЯ ГНОЙНО-НЕКРОТИЧЕСКИХ ОСЛОЖНЕНИЙ СИНДРОМА ДИАБЕТИЧЕСКОЙ СТОПЫ С ПРИМЕНЕНИЕМ ОРИГИНАЛЬНОЙ ХИРУРГИЧЕСКОЙ МЕТОДИКИ НА ФОНЕ ЦЕЛЕНАПРАВЛЕННОЙ АНТИБИОТИКОТЕРАПИИ

The comparative analysis of the treatment of 1136 patients with purulent- necrotic complications of diabetic foot syndrome (SDS ), treated with traditional surgical technique without suturing the wound ( 357 people ) and using the surgical benefits, based on the radical remove necrosis and closed wounds administered in combination with a targeted antibiotic therapy (779 persons). In the first group of amputation at the hip were performed in 35 cases (9.8%), atthe level of the tibia - in 63 patients (17.7%) and operations atthe foot suffered 259 (72.5 %) patients. In 171 cases (47.9%) were retried surgery and amputation at a higher level. Mortality rate was 16%. In the second group of amputation at the hip were performed in 13 cases (2 %), at the level of the tibia - in 38 patients (4.8%) and operations at the foot suffered 728 (93.2 %) patients. In the main group targeted application antibiotic therapy postoperative contributed favorable course of wound healing and primary wound healing in 71.9 % of cases. The progression of the inflammatory changes observed on the foot, respectively, in 28.1% cases that require repeated surgical implement, and 18 (2.3 %) patients had an amputation at the level of execution tibia or femur. Mortality reported at 3.3%. Application of the developed method for the treatment of purulent- destructive processes in patients with SDS has reduced the number of high amputation and mortality in 4 to 4.8 times.Представлен сравнительный анализ лечения 1136 пациентов с гнойно-некротическими осложнениями синдрома диабетической стопы (СДС), получавших лечение традиционным хирургическим способом без ушивания раны (357 человек) и с применением хирургического пособия, базирующегося на радикальной некрэктомии и закрытом ведении раны в сочетании с целенаправленной антибиотикотерапией (779 человек). В первой группе ампутации на уровне бедра были проведены в 35 случаях (9,8%), на уровне голени - у 63 пациентов (17,7%) и операции на уровне стопы перенесли 259 (72,5%) человек. В 171 случае (47,9%) проводились повторные оперативные вмешательства и ампутации на более высоком уровне. Летальность составила 16%. Во второй группе ампутации на уровне бедра были проведены в 13 случаях (2%), на уровне голени - у 38 пациентов (4,8%) и операции на уровне стопы перенесли 728 (93,2%) человек. В основной группе произошло первичное заживление ран в 71,9% наблюдений. Прогрессирование воспалительных изменений на стопе отмечено, соответственно, в 28,1% случаев, что потребовало повторного хирургического внедрения, а у 18 (2,3%) пациентов выполнения ампутации на уровне голени или бедра. Летальность зарегистрирована на уровне 3,3%. Применение разработанного способа лечения гнойно-деструктивных процессов у больных СДС позволило снизить число высоких ампутаций в 4 и летальность - в 4,8 раза.

ПРИМЕНЕНИЕ МИКРОХИРУРГИЧЕСКИХ ТЕХНОЛОГИЙ В ХИРУРГИИ ТОНКОЙ И ОБОДОЧНОЙ КИШКИ В УСЛОВИЯХ ЭКСПЕРИМЕНТАЛЬНОЙ КИШЕЧНОЙ НЕПРОХОДИМОСТИ И РАЗЛИТОГО ПЕРИТОНИТА

The article contains data of morphological analysis of wound healing and anastomosis of small and middle intestine, formed with appliance of microsurgical operative procedures, taking into consideration the stages of pathological process and type of microsurgical sutures. The article shows the meaning of peculiarities of microanatomy of the wall in small and middle intestine in case of obstruction and peritonitis, at implementation of microsurgical administration of operation. It also shows possibility and effectiveness of implementation of microsurgical technology while wound closure of small and middle intestine in peritonitis and application of colonic anastomosis at intestinal obstruction. Possibility of wound and anastomosis healing is proved.Приведены данные морфологического анализа заживления ран и анастомозов тонкой и ободочной кишки, сформированных с применением микрохирургических оперативных приемов с учетом стадии патологического процесса и вида микрохирургического шва. Определено значение особенностей микроанатомии стенки тонкой и ободочной кишки при непроходимости и перитоните, при применении микрохирургических приемов операции. Показана возможность и эффективность применения микрохирургической технологии при ушивании ран тонкой и ободочной кишки на фоне перитонита и наложения толстокишечных анастомозов при кишечной непроходимости. Доказана возможность заживления ран и анастомозов по типу первичного.

Attacks based on malicious perturbations on image processing systems and defense methods against them

Systems implementing artificial intelligence technologies have become widespread due to their effectiveness in solving various applied tasks including computer vision. Image processing through neural networks is also used in securitycritical systems. At the same time, the use of artificial intelligence is associated with characteristic threats including disruption of machine learning models. The phenomenon of triggering an incorrect neural network response by introducing perturbations that are visually imperceptible to a person was first described and attracted the attention of researchers in 2013. Methods of attacks on neural networks based on malicious perturbations have been continuously improved, ways of disrupting the operation of neural networks in processing various types of data and tasks of the target model have been proposed. The threat of disrupting the functioning of neural networks through these attacks has become a significant problem for systems implementing artificial intelligence technologies. Thus, research in the field of countering attacks based on malicious perturbations is very relevant. This article describes current attacks, provides an overview and comparative analysis of such attacks on image processing systems based on artificial intelligence. Approaches to the classification of attacks based on malicious perturbations are formulated. Defense methods against such attacks are considered, their shortcomings are revealed. The limitations of the applied defense methods that reduce the effectiveness of counteraction to attacks are shown. Approaches and practical measures to detect and eliminate harmful disturbances are proposed