Characteristics of the electric field accompanying a longitudinal acoustic wave in a metal. Anomaly in the superconducting phase

The temperature dependence of the amplitude and phase of the electric potential arising at a plane boundary of a conductor when a longitudinal acoustic wave is incident normally on it is investigated theoretically and experimentally. The surface potential is formed by two contributions, one of which is spatially periodic inside the sample, with the period of the acoustic field; the second is aperiodic and arises as a result of an additional nonuniformity of the electron distribution in a surface layer of the metal. In the nonlocal region the second contribution is dominant. The phases of these contributions are shifted by approximately \pi /2. For metals in the normal state the experiment is in qualitative agreement with the theory. The superconducting transition is accompanied by catastrophically rapid vanishing of the electric potential, in sharp contrast to the theoretical estimates, which predict behavior similar to the BCS dependence of the attenuation coefficient for a longitudinal sound.Comment: 9 pages, 6 figure

TWO STOCHASTIC MODELS FOR AIR TRAFFIC CONTROL OPTIMIZATION

Розглянуто дві стохастичні оптимізаційні моделі: для системи планування польотів вантажних літаків, що обслуговує рейси двох типів, та для системи планування польотів регулярних та спеціальних пасажирських рейсів. Рассмотрены две стохастические оптимизационные модели: для системы планирования полетов грузовых самолетов, обслуживающих рейсы двух типов, и для системы планирования полетов регулярных и специальных пассажирских рейсов

Magnus force and acoustic Stewart-Tolman effect in type II superconductors

At zero magnetic field we have observed an electromagnetic radiation from superconductors subjected by a transverse elastic wave. This radiation has an inertial origin, and is a manifestation of the acoustic Stewart-Tolman effect. The effect is used for implementing a method of measurement of an effective Magnus force in type II superconductors. The method does not require the flux flow regime and allows to investigate this force for almost the whole range of the existence of the mixed state. We have studied behavior of the gyroscopic force in nonmagnetic borocarbides and Nb. It is found that in borocarbides the sign of the gyroscopic force in the mixed state is the same as in the normal state, and its value (counted for one vortex of unit length) has only a weak dependence on the magnetic field. In Nb the change of sign of the gyroscopic force under the transition from the normal to the mixed state is observed.Comment: 4 pages, 5 figure

Elastic constants of borocarbides. New approach to acoustic Measurement technique

A new version of the phase method of determining the sound velocity is proposed and implemented. It utilizes the ``Nonius'' measurement technique and can give acceptable accuracy (~1%) in samples of submillimeter size. Measurements of the sound velocity are made in single-crystal samples of the borocarbides RNi2B2C (R = Y,Lu,Ho). The elastic constants and the Debye temperature are calculated.Comment: 5 figures, 2 table

Influence of antibiotic treatment duration on the development of antibiotic resistance

Avoidance of unnecessary antimicrobial administration is a key point of antimicrobial stewardship; knowing the optimal duration of therapy obviates over-treatment. In this article we have highlighted the results of modern research on the influence of the duration of antibiotic use on the success of treatment and the development of resistance of microorganisms. Foreign literary sources and the results of scientific research by experts in this field are analyzed. Based on the research results, the following conclusions were made. The results of modern studies on the duration of antibiotic use show that short-course antibiotic therapy is superior to usual long-course antimicrobial treatment. A short course of antibiotic therapy usually leads to the same positive clinical outcomes, a lower rate of antibiotic resistance and the number of clinical relapses. The two most important potential complications associated with the duration of antibiotic therapy are incomplete treatment and the emergence of antibiotic resistance. The time points used for antibiotic treatment (clinical or bacteriological cure, relapses, etc.) are subjective, complex and unreliable. The effectiveness of procalcitonin or other blood parameters for use in monitoring antibiotic treatment requires more focused studies. Despite the high relevance and publicity of various aspects of antibiotic therapy in the practice of human and animal healthcare, research on the efficacy and consequences of short-term antibiotic therapy in veterinary medicine is limited. More attention should be paid to this issue, especially in the field of animal husbandry

Hematospermia: norm or pathology? Modern approaches to etiopathogenesis, diagnosis and treatment

In most cases, the cause of blood appearance in the semen remains unknown. According to WHO, about 15 % of men experience only one episode of hematospermia, which is never repeated again. Hematospermia cause determination includes clinical examination by an urologist-andrologist and thorough patient history. The main purpose of the examination is to diagnose or exclude andropathology and also to determine the tactics of patients with hematospermia treatment. Aim. To show the relevance of this problem in reproductive medicine, to describe ethiopatogenesis of hematospermia and consider the basic methods of this pathological symptom modern diagnosis and treatment based on the specialized literature data analysis. The presence of blood in the semen can indicate a serious disease, which is the result of andropathology. The exact percent of hematospermia cases is unknown, because ejaculates go unnoticed in the process of unprotected intercourse. The most of patients consult a specialist immediately after the first episode of hematospermia. The basic points are a clinical examination and careful anamnesis. The main purpose of patients with hematospermia examination is determination of the cause or specific condition, which must be cured, and thus the symptomatology and pathological condition irradiation. To confirm the fact of hemospermia, if it’s necessary, a "contraceptive test" can be used, which consists of pathological ejaculate collection into a condom for examination. Further an urologist-andrologist examine the patient, find out an anamnesis, assign a seminal fluid analysis, a clinical and urine culture analysis, a test of blood clotting factors, a clinical blood analysis, ultrasound of the prostate by the TRUS method, prostate-specific antigen (PSA) test, alpha-fetoprotein (AFP), β-subunit of human chorionic gonadotropin (hCG) and blood serum lactate dehydrogenase (LDH) for oncopathology exclusion. Etiologic factor elimination is essential for patients with hemospermia treatment. Due to increased amount of literature data and great advances in the ultrasound diagnostics, many causes of hemospermia have been identified, so the methods of this symptom treatment are also various: conservative and surgical, which completely depend on the etiologic factor. If the pathological condition is not found, then the doctor should be as a psychotherapist to correct the sexual behavior in such men. Conclusions. Blood in the semen can evidence a serious disease, which is the result of andropathology. To determine the cause of hematospermia, it is necessary to perform a clinical examination by an urologist-andrologist and careful anamnesis. The main purpose of examination is to identify or exclude the pathology and, if it is not defined, doctor should encourage the patient on his good health. There are obligatory procedures: a seminal fluid analysis, a clinical and urine culture analysis, a test of blood clotting factors, a clinical blood analysis and ultrasound examination of the prostate by the TRUS method, PSA, AFP, hCG, LDH blood serum tests for malignant etiology of hematospermia exclusion. Modern methods of investigation allow identifying cause of hematospermia in many cases and the most patients are treated conservatively depending on the etiologic factor, but also surgical correction can be used

ДИСТАНЦІЙНЕ НАВЧАННЯ НА КАФЕДРІ СІМЕЙНОЇ МЕДИЦИНИ ДЗ «ДНІПРОПЕТРОВСЬКА МЕДИЧНА АКАДЕМІЯ МОЗ УКРАЇНИ» ОЧИМА СТУДЕНТІВ-МЕДИКІВ ДРУГОГО КУРСУ (АНАЛІЗ РЕЗУЛЬТАТІВ АНОНІМНОГО АНКЕТУВАННЯ)

Information computer technologies have become an integral part of the educational process of the modern generation of students, including students of medical universities, in complex pandemic conditions, which led to the direction of this study, namely the analysis of the opinion of students of medical universities on the use of distance learning in quarantine during the COVID-19 pandemic. That is why the purpose of our study was to analyze the results of an anonymous questionnaire survey of second year students of the Faculty of Dentistry of Dnipropetrovsk Medical Academy, in order to meet their own expectations regarding the quality of training in a remote format in the COVID-19 quarantine during the study of the discipline “Propaedeutics of Internal Medicine”, which will assess the format of on-line teaching through the “students’ eyes”.  To achieve the above goal, an anonymous online research was conducted on 2 groups of foreign (Russian-speaking) second year students (n = 45 students) using the Google Form platform. Summarizing the results of the anonymous survey stated that there is a different level of assessment (in points from 1 to 10) such a component as the justification of own expectations regarding the quality of training in a remote format – the distribution of the average was 8 points (ME = 8 Q1; Q3 (7; 9,75 )), but the quality of the level of improvement to own practical skills – only 5.5 points (ME = 5.5 Q1; Q3 (5, 8)). A frequent suggestion to improve the quality of education, according to the second year students of the Faculty of Dentistry, is to increase opportunities for practicing skills and professional competencies. In the majority of second year students of the Faculty of Dentistry have an opinion on receiving positive experience of study in a distance format, considering it as an opportunity for self-development and independent deepening of the knowledgebase. The second year students of the Faculty of Dentistry, while studying the discipline “Propaedeutics of Internal Medicine”, consider that the distance form of education can only be an addition to the full-time part, not as a long independent unit of the educational process, so the specificity of the chosen profession is associated with the need to learn and improve practical skills and professional competencies.Інформаційні комп’ютерні технології стали невід’ємною частиною освітянського процесу сучасного покоління студентів, у тому числі і студентів медичних ВНЗ, за складних протипандемічних умов, що обумовило напрямок дійсного дослідження, а саме аналіз думки студентів медичних вузів щодо використання дистанційного навчання в умовах карантину під час пандемії COVID-19. Саме тому метою нашого дослідження було провести аналіз результатів анонімного анкетування студентів 2 курсу стоматологічного факультету ДЗ «ДМА», щодо виправдання власних сподівань у відношенні до якості підготовки в дистанційному форматі в умовах карантину COVID-19 під час вивчення дисципліни «Пропедевтика внутрішньої медицини», що дозволить дати оцінку формату on-line викладання очима студентів. Для реалізації вищезазначеної мети було проведено анонімне онлайн-опитування 2-х груп іноземних (російськомовних) студентів 2 курсу (n = 45 студентів) за допомогою платформи Google Form. Узагальнення результатів анонімного анкетування констатувало наявність різного рівня оцінювання (в балах від 1 до 10) такої складової, як виправдання власних сподівань щодо якості підготовки в дистанційному форматі – інтерквартильний розподіл середньої становив 8 балів (МЕ = 8 Q1; Q3 (7; 9,75)), але якість рівня покращення власних практичних компетенцій – лише 5,5 бала (МЕ = 5,5 Q1; Q3 (5; 8)). Найчастішою пропозицією для покращення якості навчання, на думку студентів 2 курсу стоматологічного факультету, є збільшення можливостей для відпрацювання практичних навичок та професійних компетенцій. У переважній більшості студенти 2 курсу стоматологічного факультету мають думку щодо отримання позитивного досвіду навчання в дистанційному форматі, розцінюючи його як нагоду для саморозвитку та самостійного поглиблення теоретичної бази знань. Студенти 2 курсу стоматологічного факультету при вивченні дисципліни «Пропедевтика внутрішньої медицини» вважають, що дистанційна форма навчання може бути лише доповненням до очної частини, а не як тривала самостійна одиниця освітнього процесу, отже, специфіка обраної професії пов’язана з необхідністю засвоєння і вдосконалення практичних навичок та професійних компетенцій

Fragment-aided recognition of images under poor lighting and additive impulse noises

On the base of the first-order integral disproportion functions, two algorithms recognizing fragments of standard images are proposed. Due to the disproportion functions techniques, the algorithms have special advantages when processing poorly lighted images, as well as with signals transmitted in the presence of additive impulse noises