113 research outputs found
Fluorine distribution during thermal treatment of sulfuric acid leaching products of complex beryllium raw materials at JSC UMP
X-ray diffraction, infrared spectroscopy, thermogravimetry and mass spectrometry were employed to study the behavior and distribution of fluorine in sulfuric acid treatment of the melt of beryl-bertrandite-phenakite-fluorite concentrates with alkali fluxes. It was established that fluorine in a solid phase is predominantly present in the form of sodium and calcium fluorosilicates and in a gaseous phase it is evolved in the form of silicon tetrafluoride and fluorosulfonic acid
Universal Continuous Model of Active Power Factor Correctors
The purpose of the work is to develop continuous mathematical models of power factor correctors for switch-mode power supplies. The models are designed to solve optimization problems aimed at increasing the energy efficiency of these devices. This goal was achieved by developing a universal continuous averaged model of switch-mode voltage converters, which are an integral part of any active power factor corrector. State-space averaging method was proposed for constructing such a universal model. It has been shown that such a model adequately reproduces the processes in any of the main types of DC-DC voltage converters. The possibility of constructing a mathematical model of an active power factor corrector based on the proposed universal model of a DC-DC voltage converter is substantiated. The features of the structures of active power factor correctors for switching power supplies are considered and the problems that arise when studying their energy efficiency are shown. By simulation in the time domain with using the constructed model, diagrams of transients of the power factor corrector during load and primary network voltage disturbances are obtained. The most important result is the creation of a universal continuous mathematical model of switching voltage regulators. This model, unlike previously proposed models, is suitable for use in the analysis, modeling and design of any power factor correctors without the need to modify it in each specific case. The significance of the results obtained lies in accelerating the design process of active power factor correctors built on the basis of any type of pulsed DC-DC voltage converters. The developed model is intended for use in the Micro-Cap electronic circuit analysis program. However, since it is ultimately a software module in the SPICE language, this model can be used in many circuit analysis programs that support this language
A formalized representation of the target function of the impact of malicious software on the operating environment of a special-purpose automated control system
The article presents the main provisions of the theory of functional modeling in relation to solving an important and relevant problem for the methodology of information security managing – the development of mathematical models characterizing the dynamic capabilities of malware to implement destructive effects on critical information infrastructure objects. As a result of the analysis of the models that pose a threat to information security through the use of malicious codes, such as the "chain of cyber intrusions", the "unified chain of cyber intrusions", the basic and advanced models of Diamond intrusion analysis, the ATT&CK model, an up-to-date version of the functional model in the IDEF0 notation of the process of malware destructive impact on the operating environment of a special-purpose automated control system was built. The process of malware exposure is decomposed into individual stages, tactics, and techniques. The purpose of the research was to develop a variant of the malware impact on a special-purpose automated control system as a method of violating the state of information security and its processes of the system under consideration. The obtained results are a tool for the formalized presentation of the described processes in terms of the Markov processes and the development of analytical models, appropriate temporal and probabilistic characteristics for quantitative assessment of the intruder's ability to implement threats to the information security state in special-purpose automated control systems, through the malware impact
Whole exome sequencing links dental tumor to an autosomal-dominant mutation in ANO5 gene associated with gnathodiaphyseal dysplasia and muscle dystrophies
Tumors of the jaws may represent different human disorders and frequently associate with pathologic bone fractures. In this report, we analyzed two affected siblings from a family of Russian origin, with a history of dental tumors of the jaws, in correspondence to original clinical diagnosis of cementoma consistent with gigantiform cementoma (GC, OMIM: 137575). Whole exome sequencing revealed the heterozygous missense mutation c.1067G \u3e A (p.Cys356Tyr) in ANO5 gene in these patients. To date, autosomal-dominant mutations have been described in the ANO5 gene for gnathodiaphyseal dysplasia (GDD, OMIM: 166260), and multiple recessive mutations have been described in the gene for muscle dystrophies (OMIM: 613319, 611307); the same amino acid (Cys) at the position 356 is mutated in GDD. These genetic data and similar clinical phenotypes demonstrate that the GC and GDD likely represent the same type of bone pathology. Our data illustrate the significance of mutations in single amino-acid position for particular bone tissue pathology. Modifying role of genetic variations in another gene on the severity of the monogenic trait pathology is also suggested. Finally, we propose the model explaining the tissue-specific manifestation of clinically distant bone and muscle diseases linked to mutations in one gene
Остеопороз у больных муковисцидозом: новая проблема и нерешенные вопросы
Osteoporosis in cystic fibrosis patients: a new problem and unresolved issues.Остеопороз у больных муковисцидозом: новая проблема и нерешенные вопросы
High sleep reactivity: clinical, psychological and polysomnographic features
Background. The model of sleep reactivity to stress considers sleep reactivity to stress as a link in the pathogenesis of insomnia disorder – the degree to which stress disturbs sleep, which manifests as difficulty in initiating and maintaining sleep.The aim. To study clinical and psychological features as well as subjective and objective sleep indexes of subjects with high level of sleep reactivity to stress.Materials and methods. The psychological status, subjective indexes of sleep and sleep reactivity to stress according to Ford Insomnia Response to Stress Test were studied among 18–75 year-old subjects without significant sleep disturbances and patients with chronic insomnia. Polysomnography was performed for objective evaluation of sleep parameters.Results. It was found that individuals with high levels of sleep reactivity to stress were characterized by high levels of anxiety, restlessness, and neuroticism. According to results of Pittsburg questionnaire, a lower quality of sleep was revealed. These findings were correlated with objective indexes of sleep according to polysomnographic studies: less deep sleep and its lower efficiency due to sleep disturbances.Conclusions. Individuals with high sleep reactivity to stress are characterized by greater anxiety combined with subjective and objective sleep disturbance like insomnia type
The use of LLIF technology in adult patients with degenerative scoliosis: retrospective cohort analysis and literature review
Introduction Incidence of adult degenerative scoliosis (ADS) among individuals over 50 years old reaches 68%. Surgical interventions aimed at correcting the spinal deformity in patients of the older age group are accompanied by a high risk of complications. The use of LLIF is associated with lower complications as compared with open anterior or posterior fusion. Materials and methods Seventy-one patients with ADS (13 men, 58 women) were operated at the Federal Neurosurgical Center. Their average age was 60.4/60 (average/median) [55;64.5] (1: 3 quartile) years. The follow-up was from 12 to 18 months. X-ray study, SCT, MRI of the lumbar spine were used. Questionnaire surveys were conducted using the visual analog pain scale (VAS), Oswestry Disability Index (ODI) and the Short Form-36 (SF-36). Deformity correction was estimated in the frontal plane with Cobb’s method. Scoliosis was classified according to SRS-Schwab classification. Parameters of sagittal balance were estimated: PI (Pelvic incidence), SS (Sacral slope), PT (Pelvic tilt), LL (Lumbar lordosis). SVA, PT and PILL (PI minus LL) were defined adjusted for the age. Results Back pain according to VAS relieved from 6.1/6 [4;8] to 2.2/2 [2;3] points (p < 0.001) and was statistically significant at 12 months after the surgery. Leg pain according to VAS decreased from 5.4/5 [4;8] to 2.1/2 [1;3] points (p < 0.001) and was statistically significant at 12 months after the surgery. Functional adaptation according to ODI improved from 51.2/52.2 [38.6;64.1] to 31.8/33.3 [26.1;35.9] (p < 0.001). According to SF36, PH before the surgery was 25.7/24.3 [21.8;28.9] on average and at 12 months after the surgery - 38.7/38.7 [35.4;41.2] (p < 0.001). SF-36 MH before surgery was 27.1/26.3 [21.8;31.4] on average and 12 months later – 41.3/40.6 [36.5;43.7] (p < 0.001). PT before the surgery was 23.3/22° [17.5;28], 12 months later it was 17.9/17° [15;20] (p < 0.001). PI-LL was 11.5/10 ° [4;17.5], 12 months later – 8.4/8 ° [5.5;11.5] (p = 0.11). Transient paresis of femur flexors on the ipsilateral side was observed in five (7 %) cases; transient hyposthesia on the anterior thigh surface occurred in eight (11.2 %) cases. There were two cases of medial malposition (0.4 %) of pedicle screws (474 screws), pseudoarthrosis at two levels (1.2 %) (Grade 4 Bridwell) out of 166 levels performed, and seven (4.2 %) cases of damage to cortical endplates. Conclusion Restoration of local sagittal balance in ADS patients by short-segment fixation using LLIF technology leads to a statistically significant improvement in the quality of life and increases functional adaptation. Few early and late postoperative complications, less intraoperative blood loss and shorter hospital stay make LLIF in combination with MIS transpedicular fixation a method of choice in determining the surgical tactics for ADS in elderly and old age patients
Local representative democracy and protest politics:the case of the Five-star Movement
In recent years, protest politics has become a relevant phenomenon in various European countries. Italy has witnessed the rise of the Five-star Movement (M5S), an anti-establishment party, which, at the 2013 general election, obtained one-fourth of the total votes. However, the story of this ‘party-movement’ started at the local level, as a civic network aimed at changing administrative practices in municipal government. By using an original dataset on representation in 671 Italian municipalities from 2010 to 2014, this article aims to explain not only the subnational political success of the M5S but also the challenges and contradictions that a newly formed movement faces in multi-level electoral arenas
Ингаляционный маннитол – новый муколитический препарат для лечения муковисцидоза
Mucolytics with efficacy approved for cystic fibrosis (CF) have been reviewed by the authors. Currently, investigators search for new mucoactive agents to improve sputum rheology and expectoration in CF. One the promising mucolytics is inhaled dry powder mannitol which was effective and safe in several international trials. Inhaled mannitol has been implemented in clinical practice for CF treatment in some countries. Therefore, goals of new studies should be optimization the use, determination the target population and investigation of combined therapy with different mucolytics in CF.Обзор посвящен использованию современных муколитических препаратов с доказанной эффективностью при муковисцидозе. Подробно представлены результаты клинических исследований применения гипертонического раствора и маннитола у пациентов с муковисцидозом. Приводится краткая информация о проводимых в настоящее время клинических исследованиях экспериментальных муколитических препаратов
ВАЗОНЕВРАЛЬНАЯ КОМПРЕССИЯ: СООТНОШЕНИЯ СОСУДА И REZ У ПАЦИЕНТОВ С ТРИГЕМИНАЛЬНОЙ НЕВРАЛГИЕЙ
Trigeminal neuralgia in most cases caused by compression of trigeminal nerve or its branches with vessels. Compression may locate in root entry zone (REZ) or in a distance from it. The aim of the study is to compare distances from REZ of trigeminal nerve to offending vessel on the symptomatic side to distance to the same vessel on asymptomatic side. Comparing this distances showed significantly shorter distance on symptomatic side. Thus, it could be concluded that this factor has its part in development of trigeminal neuralgia.Тригеминальная невралгия чаще всего вызывается компрессией тройничного нерва или его ветвей сосудистыми структурами. Компрессия может происходить как в зоне выхода корешка из ствола, так называемой root entry zone (REZ), так и на его протяжении. Целью данного исследования является сравнение расстояния от выходной зоны нервного корешка 5-го нерва до «виновного» сосуда в сравнении с аналогичным параметром асимптомной стороны. При сравнении этих показателей расстояние на симптомной стороне было меньше, чем на асимптомной. Это позволяет сделать вывод о влиянии данного фактора на развитие тригеминальной невралгии
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