The nonlinear effects in 2DEG conductivity investigation by an acoustic method

The parameters of two-dimensional electron gas (2DEG) in a GaAs/AlGaAs heterostructure were determined by an acoustical (contactless) method in the delocalized electrons region ($B\le$2.5T). Nonlinear effects in Surface Acoustic Wave (SAW) absorption by 2DEG are determined by the electron heating in the electric field of SAW, which may be described in terms of electron temperature $T_e$. The energy relaxation time $\tau_{\epsilon}$ is determined by the scattering at piezoelectric potential of acoustic phonons with strong screening. At different SAW frequencies the heating depends on the relationship between $\omega\tau_{\epsilon}$ and 1 and is determined either by the instantaneously changing wave field ($\omega\tau_{\epsilon}$$<1$), or by the average wave power ($\omega\tau_{\epsilon}$$>1$).Comment: RevTeX, 5 pages, 3 PS-figures, submitted to Physica Status Sol.(Technical corrections in PS-figs

Implementation of the state economic policy in the field of education

The relevance of the analyzed issue is caused by the need to study the mutual development of higher education and basic factors of the production system. The purpose of this paper is the development of theoretical positions of state regulation of higher education systems, as well as the development of practical recommendations for the implementation of the economic policy at the present stage of development. The leading approaches in the study of this issue are historic-economic, institutional and evolutionary, econometric modeling elements allowing justifying the trend of the higher education development in the current period. It is proved that changes in economic policy conditions are associated with the implementation of irreversible transformations occurring in the factors of production. It is shown that these changes dictate cyclical fluctuations, as well as the evolution of the behavior and preferences of consumers. The contents of this article may be useful in the development of a state strategy to modernize higher education and the overall economic policy. © 2016 Malikh et al

Electron localization in sound absorption oscillations in the quantum Hall effect regime

The absorption coefficient for surface acoustic waves in a piezoelectric insulator in contact with a GaAs/AlGaAs heterostructure (with two-dimensional electron mobility $\mu= 1.3\times 10^5 cm^2/V\cdot s)$ at T=4.2K) via a small gap has been investigated experimentally as a function of the frequency of the wave, the width of the vacuum gap, the magnetic field, and the temperature. The magnetic field and frequency dependencies of the high-frequency conductivity (in the region 30-210 MHz) are calculated and analyzed. The experimental results can be explained if it assumed that there exists a fluctuation potential in which current carrier localization occurs. The absorption of the surface acoustic waves in an interaction with two-dimensional electrons localized in the energy "tails" of Landau levels is discussed.Comment: RevTeX 6 pages+6 EPS pic

Wound analgesia in a patient with hemophilia in a highly traumatic operation

Given a number of limitations on the use of perioperative analgesia in patients with hemophilia, wound analgesia may be one of the components of multimodal analgesia in this category of patients. The aim of the study was to describe the use of the wound analgesia method in a patient with hemophilia in the case of a clinical case. Materials and methods. A patient with severe hemophilia A underwent postoperative analgesia after total knee replacement (within the first 48 hours) with an extended infusion of local anesthetic (ropivacaine) into the wound. Results. During the first 8 hours, the patient received 20 mg of morphine (with the aid of a device for patient-controlled analgesia), the pain level ranged from 7 to 4 points. Further, there was a sufficient effect (NRS - 2 points), from anesthesia only with ropivacaine, using a system for anesthetizing surgical wounds. Complications and side effects were not noted. Conclusion. The clinical case demonstrates an effective and safe method of prolonged analgesia in patients with hemophilia. Considering encouraging data, further study of wound analgesia in this category of patients is necessary

Magnetic-field-dependent zero-bias diffusive anomaly in Pb oxide-n-InAs structures: Coexistence of two- and three-dimensional states

The results of experimental and theoretical studies of zero-bias anomaly (ZBA) in the Pb-oxide-n-InAs tunnel structures in magnetic field up to 6T are presented. A specific feature of the structures is a coexistence of the 2D and 3D states at the Fermi energy near the semiconductor surface. The dependence of the measured ZBA amplitude on the strength and orientation of the applied magnetic field is in agreement with the proposed theoretical model. According to this model, electrons tunnel into 2D states, and move diffusively in the 2D layer, whereas the main contribution to the screening comes from 3D electrons.Comment: 8 double-column pages, REVTeX, 9 eps figures embedded with epsf, published versio

Курация больных с ревматическими пороками сердца в амбулаторных условиях

The major tasks of a follow-up of patients with rheumatic cardiac defects (RCD) are formulated on the basis of the recommendations of international and national scientific associations. At the same time, a clinicianXs experience and judgments play an important role in supervising patients with chronic rheumatic heart disease and RCD.Сформулированы основные задачи диспансеризации больных с ревматическими пороками сердца (РПС) на основе базовых положений рекомендаций международных и национальных научных ассоциаций. В то же время, по мнению автора, важная роль в курации больных с хронической ревматической болезнью сердца и РПС принадлежит опыту и суждениям клинициста

Towards the matter of genetic consulting in various forms of congenital and hereditary eye diseases

Purpose. To evaluate the results in genetic consulting of patients with various forms of congenital and hereditary eyes pathology.Material and methods. The study is based on an analysis of results in genetic consulting and molecular genetic investigations of DNA samples of 18 patients: congenital corneal dystrophy (n=3); congenital cataract (n=11); Norrie disease (n = 4). All patients had a comprehensive ophthalmologic clinical and functional examination according to the forms of pathology. Geneticist physician conducted a genealogical analysis. A study of exons and flanking intronic regions was performed using methods of analysis of amplified fragment length polymorphism, restriction fragments and direct sequencing.Results. The clinical diagnosis of endothelial corneal dystrophy with autosomal recessive mode of inheritance using molecular genetic methods in 2 of the 3 cases was confirmed, and a de novo mutation in the gene SLC4A11 non-described previously was found. In the group with hereditary diseases the lens pathogenic mutations were detected in the GJA3 andGJA8 genes in 2 of 11 cases (18%). Pathogenic mutations in NDP gene were detected only in 2 of 4 family members studied, and its sibling proband, directed to the genetic analysis of patients with a clinical diagnosis Norrie disease. In another of the studied probands the diseasecausing mutation was not reveled, and thus, the molecular genetic diagnosis of Norrie disease was not confirmed.Conclusion. For the first time in the Russian Federation pathogenic mutations in the gene SLC4A11 collagen, previously did not described in the literature, were revealed in patients with congenital endothelial corneal dystrophy, in a patient with congenital cataract in the gene GJA8. The success of genetic consulting depends on the complete genealogical analysis, and the correct determination of the clinical and genetic form of pathology

Factors associated with the efficiency of maintenance therapy in patients with metastatic colorectal cancer

Objective: to evaluate tolerability and efficacy of maintenance treatment in the absence of progression after 16 weeks of first-line therapy in patients with unresectable metastatic colon cancer.Materials and methods. We have analyzed medical case histories of patients with metastatic colorectal cancer who underwent treatment in the department of clinical pharmacology and chemotherapy of N. N. Blokhin Russian Cancer Research Center from 2007 to 2015 years. Inclusion criteria were the following: 16–24 weeks of first-line chemotherapy with no signs of progression and the inability to perform metastasectomy. Progression-free survival was the main criterion for effectiveness in our study.Results. 160 (44.5 %) of 359 treated patients met the inclusion criteria. 102 (63.7 %) patients were followed up, while the other 58 (36.3 % – comparison group) patients underwent maintenance chemotherapy. Grade I–II toxic reactions and grade III complications associated with first-line chemotherapy were insignificantly more common in the group of patients left on maintenance chemotherapy: 72.4 % and 37.9 % versus 57.8 % and 24.5 % in the comparison group, p = 0.07 and p = 0.07 respectively. The frequency of grade I–II toxic reactions and grade III complications in the second-line treatment did not differ between treatment groups (p = 0.9 and p = 0.8). The median of progression-free survival in observation group and comparison group was 4, and 6 months (odds ratio (OR) 0.6; p = 0.009), and life expectancy – 23 and 31 months (OR 0.75; p = 0.1), respectively. Statistically significant differences between groups with respect to achieving the objective response and/or normalization of carcinoembryonic antigen level were revealed: median of progression-free survival was 13 (n = 26 of 57; 45.6 %) and 4 months (n = 31 of 57, 54.4 %), respectively (HR 0.38; p = 0.002), median of life expectancy – 34 months versus 26 months (OR 0.37; p = 0.3). Conclusions. Carrying out maintenance therapy is associated with increased incidence of grade III complications during the first-line treatment, but does not affect the tolerability of the second-line treatment. Supportive chemotherapy with fluoropyrimidines remains to be the most effective in patients with favorable prognostic factors such as normalization of carcinoembryonic antigen and/or achievement of the objective response on the background of first-line chemotherapy

The Role of Native Language and the Fundamental Design of the Auditory System in Detecting Rhythm Changes

Accepted December 13, 2018Purpose: We investigated whether rhythm discrimination is mainly driven by the native language of the listener or by the fundamental design of the human auditory system and universal cognitive mechanisms shared by all people irrespective of rhythmic patterns in their native language. Method: In multiple experiments, we asked participants to listen to 2 continuous acoustic sequences and to determine whether their rhythms were the same or different (AX discrimination). Participants were native speakers of 4 languages with different rhythmic properties (Spanish, French, English, and German) to understand whether the predominant rhythmic patterns of a native language affect sensitivity, bias, and reaction time in detecting rhythmic changes in linguistic (Experiment 2) and in nonlinguistic (Experiments 1 and 2) acoustic sequences. We examined sensitivity and bias measures, as well as reaction times. We also computed Bayes factors in order to assess the effect of native language. Results: All listeners performed better (i.e., responded faster and manifested higher sensitivity and accuracy) when detecting the presence or absence of a rhythm change when the 1st stimulus in an AX test pair exhibited regular rhythm (i.e., a syllable-timed rhythmic pattern) than when the 1st stimulus exhibited irregular rhythm (i.e., stress-timed rhythmic pattern). This result pattern was observed both on linguistic and nonlinguistic stimuli and was not modulated by the native language of the participant. Conclusion: We conclude that rhythm change detection is a fundamental function of a processing system that relies on general auditory mechanisms and is not modulated by linguistic experience.The authors acknowledge support from Spanish Ministry of Economy and Competitiveness Grant PSI2017-82563-P (awarded to A. G. S.), the “Severo Ochoa” Programme for Centres/Units of Excellence in R&D Grant SEV-2015-490 (BCBL), and the Basque Foundation for Science Grant IKERBASQUE (awarded to A. G. S. and M. O.). D. M. G. was supported by Grant PIA/Basal FB0003 from the Chilean Research Council. L. P. was supported by the Spanish Ministry of Economy and Competitiveness via Juan de la Cierva fellowship