THE SIMULATION RESULTS OF THE BOAT IN SHALLOW WATER

The questions are considered of the movement vessel in shallow with constant and variable depth. The equations of dynamics vessel are obtained, permitting to allow the impact on the dynamics of shallow vessel by substituting the coefficients of the equations of motion the vessel in deep water relations draft of the vessel to the depth of the waters. The mathematical model has been developed of the vessel on a given curse trajectory in shallow at variable depth

Uso das oportunidades do software messenger na educação à distância

Nowadays, the use of distance learning in the educational process of a university is becoming relevant. The current conditions stimulate and intensify the use of innovative training tools, in particular, network software products. This paper analyzed the possibilities and costs of using various digital products in an educational environment. In particular, they consider the use of mobile digital solutions for distance learning, as well as the requirements for the development of such tools by teachers who do not have the skills to create software at a professional level. The Telegram messenger example describes the experience of using instant messengers in the learning process, namely, a chat bot was created to organize the control of knowledge of students in a higher educational institution. The original chat bot, which was developed using the Telegram API interface and the Chattera chat bot designer, tests the knowledge and skills of students undergoing “General and professional pedagogy” educational discipline. This study showed that the potential of the messenger is not only in communication between users in the form of sending audio, video, and text messages, but also in its educational capabilities.Hoy en día, el uso de la educación a distancia en el proceso educativo de una universidad está cobrando relevancia. Las condiciones actuales estimulan e intensifican el uso de herramientas de formación innovadoras, en particular, productos de software de red. En este trabajo se analizan las posibilidades y costos de utilizar diversos productos digitales en un entorno educativo. En particular, consideran el uso de soluciones digitales móviles para la educación a distancia, así como los requisitos para el desarrollo de dichas herramientas por parte de profesores que no tienen las habilidades para crear software a nivel profesional. El ejemplo de Telegram messenger describe la experiencia de usar mensajería instantánea en el proceso de aprendizaje, es decir, se creó un chat bot para organizar el control del conocimiento de los estudiantes en una institución de educación superior. El chat bot original, que se desarrolló utilizando la interfaz API de Telegram y el diseñador de chat bot Chattera, evalúa los conocimientos y habilidades de los estudiantes de la disciplina educativa de “pedagogía general y profesional”. Este estudio mostró que el potencial del mensajero no está solo en comunicación entre usuarios en forma de envío de mensajes de audio, video y texto, pero también en sus capacidades educativas.Atualmente, o uso do ensino à distância no processo educacional de uma universidade está se tornando relevante. As condições atuais estimulam e intensificam o uso de ferramentas de treinamento inovadoras, em particular, produtos de software de rede. Este trabalho analisou as possibilidades e os custos do uso de vários produtos digitais em um ambiente educacional. Em particular, eles consideram o uso de soluções digitais móveis para o ensino à distância, bem como os requisitos para o desenvolvimento de tais ferramentas por professores que não possuem as habilidades necessárias para criar software a nível profissional. O exemplo do Telegram messenger descreve a experiência do uso de mensageiros instantâneos no processo de aprendizagem, ou seja, foi criado um chat bot para organizar o controle do conhecimento dos estudantes em uma instituição de ensino superior. O chat bot original, que foi desenvolvido utilizando a interface Telegram API e o designer do Chattera chat bot, testa os conhecimentos e habilidades dos estudantes que se submetem à disciplina educacional "Pedagogia geral e profissional". Este estudo mostrou que o potencial do mensageiro não está apenas na comunicação entre usuários na forma de envio de mensagens de áudio, vídeo e texto, mas também em suas capacidades educacionais

БАКТЕРИОФАГИ КАК ЭФФЕКТИВНЫЕ ПРОТИВОЭПИДЕМИЧЕСКИЕ СРЕДСТВА ДЛЯ КУПИРОВАНИЯ ВСПЫШЕК ВНУТРИБОЛЬНИЧНЫХ ИНФЕКЦИЙ

Antibiotic resistance threatens the effective prevention and treatment of healthcare associated infections which are the most frequent adverse event in health-care settings worldwide. There is an urgent need to investigate alterative preventive and treatment options while there are still a few antibiotics left. Bacteriophage (phage) therapy has been championed as a promising alternative to antibiotics.The aim of this study was to evaluate the efficacy of a therapeutic bacteriophages to control of Staphylococcus aureus and Klebsiella pneumonia outbreaks in newborn intensive care units.Materials and methods. Commercial bacteriophage cocktails targeting these paphogens was orally and locally given over 5 days to patients of neonatal intensive care units in Saint-Petersburg, Russia.Results. Bacteriophages were used as antimicrobial agents for control of three S.aureus outbreaks and one K.pneumonia outbreak. S.aureus infection incidence during the three outbreaks were 22.2%, 54.5% and 50.0% accordingly, and K.pneumoniae outbreak – 19.0%. After application of the phage cocktails among newborns, the incidence of infections caused by S.aureus and K. pneumoniae decreased to zero. All treatments were well tolerated. No adverse events were reported.Conclusion. Presented results clearly demonstrate high efficiency of bacteriophages. Phages have several features that make them potentially attractive antibacterial agents. Bacteriopahges are highly specific and very effective in destroying targeted bacteria, have only minimally impact on health-protecting normal flora bacteria, safe and rapidly modifiable to combat the emergence of newly arising bacterial threats.Инфекции, связанные с оказанием медицинской по- мощи, являются одной из наиболее значимых проблем современного здравоохранения. Неуклонно растущая устойчивость возбудителей этих инфекций к антибиотикам диктует необходимость использования альтернативных способов борьбы с ними. В качестве таких средств могут выступать бактериофаги.Цель: оценка противоэпидемической эффективности бактериофагов как средств для купирования вспышек в отделениях реанимации новорожденных.Материалы и методы. Для фаготерапии использовались моно- или комбинированные препараты бактериофагов ФГУП «НПО «Микроген». Бактериофаги при- меняли в течение 5 дней местно и перорально путем введения в питательную смесь.Результаты. Бактериофаги использовались для купирования трех вспышек, вызванных S. aureus, и одной вспышки, вызванной K. pneumoniae. Частота внутри- больничного инфицирования S. aureus в ходе трех вспышек составляла 22,2%, 54,5% и 50,0% соответственно, при вспышке K. pneumoniae – 19.0%. После применения бактериофагов по описанной схеме частота инфекций, вызванных данными возбудителями, снизилась до нулевых значений.Заключение. Результаты данного исследования убедительно свидетельствуют о высокой противоэпидемической эффективности бактериофагов в условиях вспышек внутрибольничных инфекций. Ряд свойств, которыми обладают бактериофаги, в частности высокая специфичность в отношении конкретных возбудителей инфекций, дает им преимущество перед другими антибактериальными средствами

Determination of the mass of the neutron star in SMC X-1, LMC X-4 and Cen X-3 with VLT/UVES

We present the results of a spectroscopic monitoring campaign of the OB-star companions to the eclipsing X-ray pulsars SMC X-1, LMC X-4 and Cen X-3. High-resolution optical spectra obtained with UVES on the ESO Very Large Telescope are used to determine the radial-velocity orbit of the OB (super)giants with high precision. The excellent quality of the spectra provides the opportunity to measure the radial-velocity curve based on individual lines, and to study the effect of possible distortions of the line profiles due to e.g. X-ray heating on the derived radial-velocity amplitude. Several spectral lines show intrinsic variations with orbital phase. The magnitude of these variations depends on line strength, and thus provides a criterion to select lines that do not suffer from distortions. The undistorted lines show a larger radial-velocity amplitude than the distorted lines, consistent with model predictions. Application of our line-selection criteria results in a mean radial-velocity amplitude K(Opt) of 20.2 +/- 1.1, 35.1 +/- 1.5, and 27.5 +/- 2.3 km/s (1 sigma errors), for the OB companion to SMC X-1, LMC X-4 and Cen X-3, respectively. Adding information on the projected rotational velocity of the OB companion (derived from our spectra), the duration of X-ray eclipse and orbital parameters of the X-ray pulsar (obtained from literature), we arrive at a neutron star mass of 1.06^{+0.11}_{-0.10}, 1.25^{+0.11}_{-0.10} and 1.34^{+0.16}_{-0.14} M{sun} for SMC X-1, LMC X-4 and Cen X-3, respectively. The mass of SMC X-1 is near the minimum mass (~1 M{sun}) expected for a neutron star produced in a supernova. We discuss the implications of the measured mass distribution on the neutron-star formation mechanism, in relation to the evolutionary history of the massive binaries.Comment: Accepted for publication in Astronomy and Astrophysic

Antioxidative vs cytotoxic activities of organotin complexes bearing 2,6-di-tert-butylphenol moieties

Copyright © 2018 John Wiley & Sons, Ltd. Two series of organotin(IV) complexes with Sn–S bonds on the base of 2,6-di-tert-butyl-4-mercaptophenol (L1SH) of formulae Me2Sn(L1S)2 (1); Et2Sn(L1S)2 (2); Bu2Sn(L1S)2 (3); Ph2Sn(L1S)2 (4); (L1)2Sn(L1S)2 (5); Me3Sn(L1S) (6); Ph3Sn(L1S) (7) (L1 = 3,5-di-tert-butyl-4-hydroxyphenyl), together with the new ones [Me3SnCl(L2)] (8), [Me2SnCl2(L2)2] (9) (L2 = 2-(N-3′,5′-di-tert-butyl-4′-hydroxyphenyl)-iminomethylphenol) were used to study their antioxidant and cytotoxic activity. Novel complexes 8, 9 of MenSnCl4 − n (n = 3, 2) with Schiff base were synthesized and characterized by 1H, 13C NMR, IR and elemental analysis. The crystal structures of compounds 8 and 9 were determined by X-ray diffraction analysis. The distorted tetrahedral geometry around the Sn center in the monocrystals of 8 was revealed, the Schiff base is coordinated to the tin(IV) atom by electrostatic interaction and formation of short contact Sn–O 2.805 Å. In the case of complex 9 the distorted octahedron coordination of Sn atom is formed. The antioxidant activity of compounds as radical scavengers and reducing agents was proved spectrophotometrically in tests with stable radical DPPH, reduction of Cu2+ (CUPRAC method) and interaction with superoxide radical-anion. Moreover, compounds have been screened for in vitro cytotoxicity on eight human cancer cell lines. A high activity against all cell lines with IC50 values 60–160 nM was determined for the triphenyltin complex 7, while the introduction of Schiff base decreased the cytotoxicity of the complexes. The influence on mitochondrial potential and mitochondrial permeability for the compounds 8 and 9 has been studied. It is shown that studied complexes depolarize the mitochondria but don't influence the calcium-induced mitochondrial permeability transition

АКТУАЛЬНЫЕ ПРИРОДНО-ОЧАГОВЫЕ ИНФЕКЦИИ, ПЕРЕДАВАЕМЫЕ КЛЕЩАМИ, В САНКТ-ПЕТЕРБУРГЕ

Purpose: to conduct a comparative analysis and to identify the epidemiological and clinical features of tick-borne encephalitis (TBE) and Lyme borreliosis as a mono- and coinfections in St. Petersburg. Materials and methods. 718 cases of TBE, 4353 cases of Lyme borreliosis and 127 combined diseases registered by the St. Petersburg epidemiological bureau in 2006-2017 were studied. Identification of combined diseases was carried out by a special software that allows to identify co-morbid diseases from the array of monoinfections. To identify clinical and epidemiological features, 144 cases of TBE, 286 Lyme borreliosis, and 43 cases of co-infection were studied. Age and sex characteristics, places of human contagion, infection rates of ticks, clinical forms of mono- and associated diseases, morbidity dynamics changes and patients’ IgM seropositivity were studied. Results. The long-term dynamics of TBE and Lyme borreliosis incidence had did not have significant upward or downward trends, it was characterized by synchronous fluctuations. The priority of the incidence of men over women is revealed. 61–69% cases of TBE and Lyme borreliosis occurred in Leningrad region, 19–30% – in the adjacent territories of Russia, 5,7–6,7% of cases were imported from other countries. High tick infection rates of TBE virus and Borrelia was revealed. Borrelia аnd virus of TBE and were detected in 81,6–87,5% of the examined ticks removed from patients with a later established diagnosis. Seasonal distribution of Lyme borreliosis was shifted by a month to the right in comparison with TBE. The clinical forms of both diseases did not differ in their structure from the country data, however after 2012 subclinical forms were more common in women. The proportion of non-erythematous forms of Lyme borreliosis in 2011–2015 compared with the 2006–2010 observation period increased almost 1,5-fold mainly forms, including those with co-infection. The IgM seropositivity rate in the dynamics of the disease testifies to the incomplete rehabilitation of patients. Conclusion. The clinical and epidemiological characteristics of TBE, Lyme borreliosis and combined infection in the North-West region of Russia, with the example of St. Petersburg, have certain distinctive features. The reasons for the revealed features need further study.Цель: провести сравнительный эпидемиологический анализ и выявить эпидемиологические и клинические особенности клещевого энцефалита и боррелиоза как моно- , так и одновременного сочетания этих инфекций у больных в Санкт-Петербурге. Материалы и методы: ретроспективно изучено 718 случаев клещевого энцефалита, 4353 случая клещевого боррелиоза и 127 сочетанных заболеваний, зарегистрированных в отделе учета и регистрации инфекционных и паразитарных заболеваний Центра гигиены и эпидемиологии Санкт-Петербурга за 2006–2017 гг. Идентификация сочетанных заболеваний происходила с помощью специальной программы, позволяющей выявлять сочетанные заболевания из массива моноинфекций. Для выявления клинико-эпидемиологических особенностей изучено 144 истории болезни клещевым энцефалитом, 286 – клещевым боррелиозом и 43 истории болезни в случаях сочетания этих инфекций. Проанализированы возрастно-половые характеристики, места заражения людей, вирусо- и борелиафорность клещей, клинические формы моно- и сочетанных заболеваний, изменения, происходящие во времени. Коэффициент серопозитивности IgM у больных оценивался в динамике обследования пациентов. Результаты: многолетняя динамика заболеваемости клещевым энцефалитом и клещевым боррелиозом не имела выраженных тенденций к росту или снижению и характеризовалась синхронными колебаниями. Выявлен приоритет заболеваемости мужчин над женщинами. Заражения клещевым энцефалитом и боррелиозами в 61–69% случаев происходили в Ленинградской области, в 19–30% – на сопредельных территориях России, в 5,7–6,7% – в странах ближнего и дальнего зарубежья. Выявлена высокая инфицированность клещей вирусом клещевого энцефалита и боррелиями. Боррелии и вирус клещевого энцефалита выявлены у 81,6 и 87,5% исследованных переносчиков, снятых с больных с позднее установленным диагнозом. Сезонное распределение заболеваний боррелиозом было сдвинуто на месяц вправо по сравнению с клещевым энцефалитом. Клинические формы как клещевого энцефалита, так и боррелиоза по своей структуре не отличались от литературных данных по стране, однако субклинические формы чаще встречались у женщин в период после 2012 г. Доля безэритемных форм боррелиоза в 2011–2015 гг. по сравнению с 2006–2010 гг. наблюдения увеличилась почти в 1,5 раза, в том числе и при сочетанной инфекции. Коэффициент серопозитивности IgM в динамике болезни свидетельствует о неполном выздоровлении больных. Заключение: клинико-эпидемиологическая картина клещевого энцефалита, клещевого боррелиоза и сочетания этих инфекций в Северо-Западном регионе России на примере Санкт-Петербурга имеет определенные отличительные особенности. Причины выявленных особенностей нуждаются в дальнейшем изучении

BACTERIOPHAGES AS EFFECTIVE ANTIEPIDEMIC AGENTS FOR CONTROL OF HOSPITAL-ACQUIRED INFECTION OUTBREAKS

Antibiotic resistance threatens the effective prevention and treatment of healthcare associated infections which are the most frequent adverse event in health-care settings worldwide. There is an urgent need to investigate alterative preventive and treatment options while there are still a few antibiotics left. Bacteriophage (phage) therapy has been championed as a promising alternative to antibiotics.The aim of this study was to evaluate the efficacy of a therapeutic bacteriophages to control of Staphylococcus aureus and Klebsiella pneumonia outbreaks in newborn intensive care units.Materials and methods. Commercial bacteriophage cocktails targeting these paphogens was orally and locally given over 5 days to patients of neonatal intensive care units in Saint-Petersburg, Russia.Results. Bacteriophages were used as antimicrobial agents for control of three S.aureus outbreaks and one K.pneumonia outbreak. S.aureus infection incidence during the three outbreaks were 22.2%, 54.5% and 50.0% accordingly, and K.pneumoniae outbreak – 19.0%. After application of the phage cocktails among newborns, the incidence of infections caused by S.aureus and K. pneumoniae decreased to zero. All treatments were well tolerated. No adverse events were reported.Conclusion. Presented results clearly demonstrate high efficiency of bacteriophages. Phages have several features that make them potentially attractive antibacterial agents. Bacteriopahges are highly specific and very effective in destroying targeted bacteria, have only minimally impact on health-protecting normal flora bacteria, safe and rapidly modifiable to combat the emergence of newly arising bacterial threats