Self-adaptive STDP-based learning of a spiking neuron with nanocomposite memristive weights.

Neuromorphic systems consisting of artificial neurons and memristive synapses could provide a much better performance and a significantly more energy-efficient approach to the implementation of different types of neural network algorithms than traditional hardware with the Von-Neumann architecture. However, the memristive weight adjustment in the formal neuromorphic networks by the standard back-propagation techniques suffers from poor device-to-device reproducibility. One of the most promising approaches to overcome this problem is to use local learning rules for spiking neuromorphic architectures which potentially could be adaptive to the variability issue mentioned above. Different kinds of local rules for learning spiking systems are mostly realized on a bio-inspired spike-time-dependent plasticity (STDP) mechanism, which is an improved type of classical Hebbian learning. Whereas the STDP-like mechanism has already been shown to emerge naturally in memristive devices, the demonstration of its self-adaptive learning property, potentially overcoming the variability problem, is more challenging and has yet to be reported. Here we experimentally demonstrate an STDP-based learning protocol that ensures self-adaptation of the memristor resistive states, after only a very few spikes, and makes the plasticity sensitive only to the input signal configuration, but neither to the initial state of the devices nor their device-to-device variability. Then, it is shown that the self-adaptive learning of a spiking neuron with memristive weights on rate-coded patterns could also be realized with hardware-based STDP rules. The experiments have been carried out with nanocomposite-based (Co40Fe40B20) х (LiNbO3-y )100-х memristive structures, but their results are believed to be applicable to a wide range of memristive devices. All the experimental data were supported and extended by numerical simulations. There is a hope that the obtained results pave the way for building up reliable spiking neuromorphic systems composed of partially unreliable analog memristive elements, with a more complex architecture and the capability of unsupervised learning.

[SUPPORT LUNG VENTILATION IN COMPLEX OF ANESTETIC MANAGEMENT DURING HIGH TRAUMATIC OPERATIONS IN VASCULAR SURGERY.]

BACKGROUND: Rejection from prolonged mechanical ventilation with conversion to support ventilation modes during the surgery and subsequent immediate extubation at the end of the surgery could be the method ofprophylaxis ofpostoperative respiratory complications. THE AIM: To improve the results of surgical treatment of patients with infrarenal aorta injury due to the development and implementation to the anesthetic management complex the modes of support ventilation. MATERIALS AND METHODS: 2-staged clinical trial on patients undergoing surgery on infrarenal aorta was conducted. At the 1st stage patients were assessed for opportunity of immediate or early extubation and support ventilation initiation. At the 2nd stage support modes during the intraoperative ventilation were introducted into clinical praxis. RESULTS: Based on received data we concluded that not everyone patient needed intra- and postoperative mechanical ventilation in spite ofprolonged duration of the surgery and large surgical trauma. Inclusion in the protocol of anesthesia support ventilation strategy decreases requirement ofparalytic agents and their side effects. CONCLUSION: Applying the support ventilation modes during the anesthesia gives a chance of immediate and early extubation after the surgery and decreases the number of critical events and respiratory complications.

[Liver resection in patient with hcc and right atrium thrombosis].

Presented herein is a case report concerning tumorous thrombosis of the inferior vena cava and right atrium, which is rather an uncommon but severe complication of primary hepatic cancer. The purpose of the article is to demonstrate successful surgical management of locally disseminated hepatic carcinoma complicated by tumorous thrombosis of the inferior vena cava and portal vein, as well as thrombosis of the right atrium. The patient was subjected to dextral hemihepatectomy with thrombectomy from the right portal vein, resection of the right cupola of the diaphragm, marginal resection of the lower lobe of the right lung, thrombectomy from the inferior vena cava and right atrium. The outcome of our case report, as well as literature data suggest that in case of resectability of hepatic tumour complicated by thrombosis of major vessels and even the heart, surgical intervention is justified if there is a possibility to completely remove thrombotic masses along with the primary tumour.

The magnetization processes and critical transition in a nanogranular magnetic film with perpendicular anisotropy.

The mechanisms and properties of the equilibrium magnetization process for nanogranular films with perpendicular anisotropy placed in a tilted magnetic field are considered. The contributions of the effects of canting and flipping of the granules' magnetic moments to the process of film magnetization are studied. A critical behavior of the film magnetization at the transition, induced by a tilted magnetic field, from a state with non-uniform orientation of the granules' magnetic moments to one with a similar orientation is revealed. The results obtained within the two-level model of the orientation of the particles' magnetic moments are in good agreement with the experimental data for Co-Al(2)O(3) (61 at.% Co) granular film. The perpendicular anisotropy of the granules in this film originates mainly from their elongated shape. It is shown that in the non-uniform state the magnetostatic energy of a granular film with similarly oriented elongated granules can be described by the sum of contributions of two types: quasi-single-granular and quasi-film. The effective constant of the single-particle anisotropy of the granules in this case turns out to be dependent on the factor of volume filling of the film by granules, but not on its magnetization.

[The rare case of Bland-White-Garland syndrome in adult patient].

We present analysis of a case history of a patient with rare congenital heart disorder - Bland-White-Garland syndrome. The 25 years old women was first diagnosed with this disorder during an examination in the cardiological department of the Moscow clinical hospital No83. The paper contains discussion of difficulties of diagnosis and peculiarities of management of adults with this pathology as well as of a problem of the choice of further therapeutic approaches.

Influence of annealing on magnetic, relaxation and structural properties of composite and multilayer films.

This work is devoted to the research of influence of annealing to ferromagnetic resonance (FMR) properties of films of the A, B series with the compositions of (Co45-Fe45-Zr10)x(Al2O3)y, multilayer films of the D series with compositions {[(Co45-Fe45-Zr10)x(Al2O3)y]-[alpha-Si]}120 and revealing their relationship with the nanostructure characteristics. The films were obtained in an argon atmosphere (the A, D series) and with addition of oxygen (the B series). All samples were deposited on substrates by the ion-beam sputtering method and were annealed. The resonant fields and width of ferromagnetic resonance (FMR) line were measured before and after annealing. The changes in the FMR field and width of the line at varying temperatures of annealing for the composite and multilayer films are analyzed in the work. The character of changes in the structural characteristics of films at different annealing temperatures is determined.

[The concept of training anesthesia-resuscitation specialists for high-technology medical aid-delivering health care facilities].

The paper presents the concept of training specialists in anesthesia-resuscitation for high-technology-delivering facilities. This concept is based on the module-axial type of education based on two basic principles: from complex to simple (from general to particular) (the so-called axis) and the modular organization of an educational process. Education implies the obligatory teaching of the axis (the structuring of the already available knowledge) and specialized programs (modules) are incorporated into a course of subjects if there is a practical need, which permits a student to achieve the necessary level of knowledge and skills.

[Noninvasive cardiac output determinations].

The thermodilution determination of cardiac output (CO) by pulmonary arterial catheterization is considered to be the gold standard. However, a diversity of complications associated with the insertion and use of a catheter has made for the design of CO-measuring devices in a mini- or noninvasive mode. This prospective controlled study has been conducted to compare various CO determination techniques by the shape of the arterial curve (ART), as shown by the use of a transesophageal Doppler ultrasonic sensor (TEDUS) determining the blood flow velocity in the descending thoracic aorta by the Fick's backward equation with partial CO2 recirculation, by measuring thoracic bioimpedance (Tbio) by bolus thermodilution as the reference method (CO BT). In all the study examined, the mean CO values are lower than those in the reference method. In addition, there was a wide scatter of the CO values calculated by alternative methods. The mean difference and its standard deviation are 1.27 +/- 2.26 (ART); 0.87 +/- 1.57 (TEDUS); 1.01 +/- 1.46 (Fick); and 1.46 +/- 1.70 (Tbio). The errors of the methods, as compared to CO BT have the following values: APT, 27% (24-31% conference interval (CI)); TEDUS, 19% (17-21% CI); Fick, 20% (19-22%); Tbio, 25% (22-27%). By taking into account the findings, it should be stated that there is not any accurate mini- or noninvasive CO determination method that could completely substitute for the classical thermodilution technique.

[Combined treatment of posttraumatic arterio-venous aneurysm between the aorta and left renal vein].

The authors present herein a case report of a patient presenting with a posttraumatic arterio-venous aneurysm between the aorta and left renal vein, which is an extremely rarely occurring disease. A method of choice in treatment of an arterio-venous aneurysm is an open operation. The clinical example presented demonstrates a possibility of using roentgenoendovascular occlusion for closing the aorto-venous fistula. We report our own experience in treatment of the diseases by means of the occluders PLUG and Amplatzer ASD, followed by a surgical intervention.

[Metabolic effects of mexidole during cardiosurgical operations using extracorporeal circulation].

The effect of mexidole on the levels of glutathione, the activity of its metabolic enzymes, glutathione reductase (GR) and glutathione peroxidase (GP), and antioxidative enzymes, superoxide dismutase (SOD) and catalase (CAT) in the red blood cells under hypothermic perfusion was studied. A total of 96 patients were examined. The study was performed before perfusion, at the cooling and warming stages, an hour after perfusion, and in the morning of a following day. Mexidole was administered to 26 patients in the evening, before surgery, and at the cooling and warming stages (Group 1). The agent was not given to 70 patients (Group 2). In Group 2, there was an association of the level of glutathione and the activity of the enzymes under study with temperature. There were the least changes observed at 30-34 and 26-29 degrees C and a substantial decrease (by more than 30%) at the cooling stage as compared with pre-perfusion values. In the mexidole group, the content of glutathione increased under all temperature conditions at the study stages (by 30 to 58%) and the activity of all the test enzymes: GR and GP up to 33%, SOD up to 20-60%, CAT by 20-30%. The elevated level of all the parameters was also preserved on the following postoperative day. It may be suggested that mexidole activates the biosynthesis of glutathione and antioxidative enzymes, thus enhancing the antioxidative defense of cell membranes.

[The first experience in using sevoflurane].

The paper analyzes the first experience in using the halogen-containing anesthetic sevoflurane, which is new for Russia, as an agent for initial narcosis and anesthesia maintenance in adult patients. For induction, delivery of sevoflurane was initiated in a dose of 0.7 r.% through the mask of an anesthetic-respiratory apparatus. After 3-5 breaths, the dose of sevoflurane was increased up to 2 r.%. The time of inhalation to the level of INEEG being achieved 40-45% was 3.2 +/- 0.5 min, while that with propofol was 3.3 +/- 1.0 min. Initial inhalational anesthesia was smooth, which did not exclude a slight short-term motor activity in 2 patients. Sevofluorane has a pronounced hypnotic, but a weak analgesic effect in adults, which requires the co-administration of fentanyl. Sevofluorane will be mostly demanded for initial narcosis and anesthesia maintenance in children and for the induction and maintenance of anesthesia in ambulatory anesthesiology and thriving one-day hospitals. The foregoing does not rule out the use of servofluorane for the induction and maintenance of anesthesia in adults.

[To the effective concentration of xenon].

The present literature discusses what effective concentration of xenon may be used to induce adequate anesthesia. To examine the analgesic properties of the substance, 38 patients undergone laparoscopic operations for calculous cholecystitis under informational saturation EEG (INEEG) monitoring were included into this study. All the patients were divided into 3 groups in accordance to the mode of anesthesia maintenance and INEEG monitoring. In Groups 1 and 2, the concentration of xenon was maintained at 70%; INEEG monitoring was made in the of-line mode. In Group 3, the concentration of xenon was gradually decreased from 70% to the minimum value at which the level of INEEG was 40-50%, which corresponds to the adequate depth of anesthesia. The use of 70% xenon concentration and the standard doses offentanyl (3.1 +/- 1.6 microg/kg/h) resulted in excessively deep anesthesia (38 +/- 4% INEEG). Reduction of the dose of fentanyl on an average to 1.5 +/- 0.8 microg/kg/h permitted more adequate anesthesia; however, an excessively deep anesthesia is encountered in 40% of cases, as evidenced by INEEG. The active use of INEEG monitoring in Group 3 makes it possible to perform an adequate anesthesia (46 +/- 4% INEEG) and to determine the xenon concentration necessary for this, which is equivalent to 42 +/- 11% with the dose of fentanyl of 0.9 +/- 0.8 microg/kg/h.

[Internal audit based on the recording critical incidents: the first results].

The critical incident concept on which an internal medical audit is based has been proposed to comparatively assess different protocols of anesthesiological support. The purpose of this study was to develop a procedure and to implement it at an anesthesiological unit. The study included and analyzed 361 anesthesiological supports. The list of critical incidents (CIs) contained 53 items and was divided into 8 main groups. CIs were recorded in 42.1% of anesthesias: a total of 304 CIs were noted and the frequency of CIs (the number of recorded CIs per anesthesia was 0.84). The bulk of CIs was associated with the cardiovascular system and varying allergic reactions. The study also yielded data on the distribution of CIs in relation to the type of anesthesiological support, the type of a surgical intervention and the physical status of a patient (according to the ASA classification). This study has only opened a little way to internal audit and showed the importance of its routine use to assess different procedures for anesthesiological support.

[Long-term outcomes of balloon angioplasty for aortic coarctation]. / Otdalennye rezul'taty ballonnoi angioplastiki koarktatsii aorty.

From 1994 to 2001 balloon angioplasty was fulfilled for 19 patients aged from 4 to 28 (mean 11.0+/-7.0) with discrete type aortic coarctation. Early outcomes were satisfactory in all cases. Catheterization showed 10 mm Hg decrease in systolic pressure gradient (SPG). Long-term results (from 6 months to 8 years, mean 3.0+/-2.5) were evaluated with transthoracic EchoCG, Doppler ultrasound, duplex scanning of iliofemoral segment and CT-angiography with 3D reconstruction. Surgical outcomes were considered good when SPG did not exceed 20 mm Hg for Doppler ultrasound and 25 mm Hg for Doppler EchoCG. In the study group there was statistically significant decrease in arterial pressure in right upper limb and SPG (measured with both Doppler EchoCG and Doppler ultrasonography) and rise of ankle-brachial index. Beneficial hemodynamic effect was detected in 15 from 19 patients (79%). Recoarctation has developed in 4 (21%) patients, in 1 (5.3%) case it was combined with true posttraumatic aortic aneurysm. Three patients underwent open surgical intervention with uneventful postoperative period. Aneurysmal dilatation of thoracic aorta has developed in 1 patient (5.3%), non-progressive intimal dissection - in another one (5.3%), 2 patients (10.5%) experienced ipsilateral 40-60% stenosis of right external iliac and femoral arteries. Thus good long-term outcomes of balloon angioplasty in patients with discrete type aortic coarctation were achieved in 79% cases. Patients after balloon angioplasty must be assessed regularly with non-invasive diagnostic methods such as Doppler ultrasonography, Doppler EchoCG, CT-angiography.

[Information method of EEG analysis in anesthesiology]. / Informatsionnyi metod analiza EEG v anesteziologii.

An information concept of nociceptive impulses is proposed. The device for quantitative analysis of information coming to CNS has been constructed and approved. It is demonstrated that monitoring of informative loading of EEG may be used for evaluation of anesthesia adequacy. Level of this index from 40 to 50% corresponds to effective protection.

[Electroencephalogram, informational saturation of electroencephalogram, and bispectral index during xenon anesthesia for laparoscopic operations]. / Elektroéntsefalogramma, informatsionnaia nasyshchennost' élektroéntsefalogrammy i bispektral'nyi indeks pri anestezii ksenonom vo vremia laparoskopicheskikh operatsii.

The depth of xenon anesthesia was never evaluated by modern methods of EEG monitoring, and hence, we studied changes in EEG, INEEG, and BIS during different stages of xenon narcosis and evaluated the possibility of using these values as criteria of xenon anesthesia adequacy. The study was carried out in 60 patients during laparoscopic operations on abdominal organs. The patients were divided into 2 groups receiving different gas anesthetics (xenon or nitric oxide). The results indicate that xenon monoanesthesia caused dose-dependent changes in the native and treated EEG; xenon is a good inhalation anesthetic providing adequate anesthesia for little traumatic operations even in case of mononarcosis; INEEG and BIS monitoring during xenon anesthesia allows an objective evaluation of its depth.

[Genetic and morphological variability of the gastropod mollusk Nucella heyseana (Mollusca, Gastropoda) in the environmental optimum and pessimum]. / Geneticheskaia i morfometricheskaia izmenchivost' briukhonogogo molliuska Nucella heyseana (Mollusca, Gastropoda) v sredovom optimume i pessimume.

Genotypic variability at six allozyme loci and six morphological shell characters was examined in 450 individuals (four samples) of mollusk Nucella heysana from the Vrangel' Bight (Nakhodka Bay) and the Vostok Bay (Peter the Great Gulf, Sea of Japan). An analysis of variation in allele frequencies showed that each of the two localities (Vostok and Nakhodka bays) in the analyzed region is inhabited by a single, albeit genetically heterogeneous, population. A canonical analysis and an analysis of variance of individual heterozygosity (Ho) and morphological variation indicate an association between Ho and morphological variation depending on habitat (interaction) in settlements in the Vrangel' Bight and, to a lesser extent, in the Vostok Bay. These results indicate that, in extreme environmental conditions, allozyme phenotypes may be selected either themselves or as markers of genes linked with them.