bluuebunny/crossref_metadata_2025 huggingface dataset:
The reduced modulus of elasticity of a layered half-space
Authors: Ogar Peter , Kozhevnikov Artem , Fedorov Vyacheslav
Published: October 2018

A layered half-space is represented as the sum of parts of homogeneous half-spaces of coating materials and the base material, the rigidity of which corresponds to the rigidities of the coating and the base. Using a rigid model of a layered elastic body loaded with an axisymmetric distributed load, a new solution is obtained for determining its reduced elasticity modulus and the Poisson’s ratio depending on the elastic characteristics of the base material, the coating material and the relative thickness of the coating. Expressions are given for the reduced elastic modulus and the Poisson’s ratio of a layered body with a two-layer coating.
A study of reconfigurable production system performance
Authors: Kapitanov Alexey , Mitrofanov Vladimir , Egorov Sergey
Published: October 2018

The article studies the methods of evaluating the effectiveness of production is built on the basis of a flexible, reconfigurable systems capable of performing fast-changing market demands. Examines the history of formation of the concept of efficiency of organization of flexible production and its main parameters estimation. Based on the performance of the production system as a communication channel, describes the main performance characteristics of the configurable production systems. Described indicators are General and do not depend on the specific application of the system, which is especially important to determine the appropriate standard values. The time required for calculation of the indicators is determined on the basis of the known methods and the proposed approach, which provides a clear semantic definition of universality, flexibility, mobility and productivity, thus strictly linking the indicators together.
The information model of the modern digital production
Authors: Kapitanov Alexey , Kozlova Aleksandra , Tyasto Sergey
Published: October 2018

The article devoted the analysis and research of modern digital production technologies that ensure the transfer of digital design to a physical object. Five target criteria of production digitalization, such as economic efficiency, prototypiny, quality control, interaction, standardization. The article analyzes the dependence of the cost of implementing new tools at the initial stage of transition to digital production and saving of enterprise resources, as well as basic tools of digital production. The concept under consideration is based on integration of mechatronic technologies, computer systems, as well as engineering analysis and adaptation of the work of various equipment and technological equipment with programmatic control. In conclusion, the list of potential advantages, the creation of digital productions at engineering enterprises on the basis of the development and implementation of new critical and high technologies.
Peculiarities of calculation the running resistances of the wire across the guides wire-tying machines
Authors: Kudryashov Aleksandr , Kopylova Olesya , Kozyr Aleksandr
Published: October 2018

Wire rod manufacturers are interested in using their own materials for strapping coils. Therefore, the competitive advantage of manufacturers of wire-tying machines may be the possibility of using wire rod as a strapping material. At the same time, the rigidity of the rod causes great efforts to feed it along the guides around the strapped section. The presented technique for calculating can be used for the scientifically based design of wire feeders of prospective wire-tying machines.
Principles of innovative reproduction strategic planning of the enterprises fixed assets in rocket and space industry
Authors: Boyko Andrey , Kukartsev Vladislav , Stupina Alena
Published: October 2018

The principles of planning the reproduction of fixed assets of the rocket and space industry enterprises are investigated, taking into account the features of their activities and the requirements for strategic planning.
Analysis of the applicability of die pressing method for ring-shaped parts fabrication
Authors: Lavrinenko Vladislav , Polyakova Anastasiya , Polyakov Artyom
Published: October 2018

This paper analyses die pressing method used for fabrication of ring-shaped parts, which assures significant metal economy. Computer simulation results obtained with PAM-STAMP software are compared with experimental data. The research outcome is the established range of applicability of die-pressing method for manufacturing ring-shaped parts.
Experimental evaluation of the operational properties of snowmobile motor vehicles
Authors: Klubnichkin Vladislav , Klubnichkin Evgeny
Published: October 2018

The article demonstrates the results of the experimental estimate of the speed and load modes as well as operational properties of the oversnow equipment during which a large number of parameters and indicators allowing for their use during designing of new generation of oversnow vehicles have been determined. This work demonstrates the results of the tests in determining speed and brake properties, as well as stability and controllability of the Russkaya Mekhanika’s oversnow vehicles, models RM Buran Leader, RM Tayga Varyag 550, RM Tayga Patrul 800 SWT, RM Vector 551i and over companies’ oversnow vehicles, models BRP Lynx Xtrim Commander 800 E-TEC, Arctic Cat Pantera 7000 XT LTD, Polaris 800 Titan Adventure 155.
Experimental evaluation of traction and coupling properties of snowmobile motor vehicles
Authors: Klubnichkin Evgeny , Klubnichkin Vladislav
Published: October 2018

The article demonstrates the results of the experimental estimate of the drawbar properties of the oversnow equipment during which parameters and indicators allowing for their use during designing of new generation of oversnow vehicles have been determined. This work demonstrates the results of the tests in determining maximum drawbar pull, determining motion resistance force with the arrested and released brake of the Russkaya Mekhanika’s oversnow vehicles, models RM Buran Leader, RM Tayga Varyag 550, RM Tayga Patrul 800 SWT, RM Vector 551i and over companies’ oversnow vehicles, models BRP Lynx Xtrim Commander 800 E-TEC, Arctic Cat Pantera 7000 XT LTD, Polaris 800 Titan Adventure 155.
Hydraulic technological machines with adaptive drive structure
Authors: Lemeshko Mikhail , Molev Mikhail , Golovin Igor
Published: October 2018

In a large group of technological machines, drive provides two interlocking working movements. In metalworking, the working process is provided by two movements of the cutting tool relative to the forms or details. As a rule, this is due to the rotational and forward movements. The ratio of speeds of these movements, the ratio of two movements, or the ratio of the brought capacities to each of these movements can be the significant indicators of working process, having the optimum value. The method of automatic maintenance of the ratio for a hydraulic actuator with two engines is considered in the article. Schematic diagrams of the drive for some technological machines are considered. Based on the example of the device intended for processing of curvilinear surfaces, the process of automatic control regulating thickness of hydraulic actuator having adaptive structure is described. The efficiency of self-regulation at rather simple circuitry decisions is shown.
Technical condition parameters affecting the period of safe operation of technological pipelines
Authors: Kulakov Petr , Rubtsov Aleksey , Afanasenko Vitaly , Gracheva Veronica
Published: October 2018

The task is to estimate the period of technological pipelines safe operation depending on the total influence of oil refining equipment technical parameters. 9 feature properties of technological pipelines were singled out, and the estimation was made with the help of such indicator as the residual life of pipelines. The authors constructed a mathematical model, calculated the diagnostic coefficients and informative character of the characteristic for each period accepted by the expert. A mechanism for estimating the safe operational lifetime of pipeline systems is proposed. Conclusions were drawn about the advisability of applying the proposed method for solving this class of problems.
An approach to technological equipment performance information visualization system construction using augmented reality technology
Authors: Chekryzhov Viktor , Kovalev Ilya A. , Grigoriev Anton S.
Published: October 2018

The approach to obtaining the necessary information from heterogeneous technological equipment with its subsequent visualization is considered in the article. It is shown that the available interface screens of control systems are often overloaded with information, which makes it difficult to work with technological equipment. A variant of the solution of the terminal problem with application of the augmented reality technologies is proposed. The basic structural schemes and algorithms of operation of such a system are described. The first test version of the proposed solution is described.
Active reduction of elastic objects oscillation tasks
Authors: Bokhonsky Aleksandr , Golovin Vasiliy , Maistrishin Mikhail
Published: October 2018

Application features of optimal control methods for oscillations of an elastic system stipulated by initial disturbance are being analyzed. The ways of the search control simplifying and their practical implementation are being estimated.
High thickness coating of zirconium dioxide for thermal protection of metal alloys
Authors: Tsareva Irina , Berdnik Olga , Maximov Maksim , Kuzmin Victor
Published: October 2018

A study was made of high thickness thermal barrier coating of zirconium dioxide (up to 2 mm) formed by the method of high-energy plasma spraying on the intermetallic layer, and designed to protect the elements of the fuselage of aircraft.
Research of structural entropy of sheet aluminium alloys depending on annealing temperature
Authors: Nosova Ekaterina , Grechnikov Fedor , Lukonina Natalia
Published: October 2018

Sheet blanks’ structure uniformity determines their ability to sheet stamping. Level of entropy may represent the characteristic of structural uniformity. Structural entropy was received from strain curves recalculation for sheet blanks from aluminium alloys Al-2Mg and Al-6Mg are presented in the work. Stain curves were provided for blanks after cold deformation and annealing at temperatures 250, 350 И 450˚C. Estimation of grain size uniformity was made. Effect of annealing temperature on structural entropy and grain structure uniformity was found. It was shown that annealing temperature increasing leads to structural entropy decreasing. Ununiformity of grain size achieves the minimal values after annealing at temperature 350˚C for both alloys, and then ununiformity grows after annealing at temperature 450˚C.
Investigation of the effect of the coating formed by microarc oxidation on the piston top on the thermal state of the internal combustion engine parts
Authors: Musin Niyaz , Dudareva Natalia
Published: October 2018

The aim of this work is to study the influence of MAO-coatings on the thermal state of the engine piston. The results of numerical modeling of the temperature distribution in the piston are presented for different values of thickness and conductivity of the coating. Regression equations are obtained. For thermal protection of the piston it is recommended to apply MAO-coatings with thermal conductivity of 0.3...0.7 W/m.K and thickness 150…300 µm.
Optimization of process of application plasma hardening coating
Authors: Smolentsev Evgeniy , Kadyrmetov Anvar , Kondratyev Mikhail
Published: October 2018

This article addresses the problem of increasing tool life by applying a wear-resisting coating. However, the lack of technology-based methods and optimal regimes complicate this process. A method for finishing plasma hardening of metals which allows evaluate the quality of the wear-resistant thin-film coatings and optimize application regimes have been advanced.
Improving the operation quality of technical systems using information theory models
Authors: Dulesov Aleksander , Karandeev Denis , Dulesova Natalia
Published: October 2018

Improving the operation quality of the technical system performance while designing and operating is considered through the application of information theory models. The models are based on the mathematical description of the probabilistic state of system elements and the possibility of determining the information entropy. To implement the model, the role of the stochastic behavior of a technical object is emphasized. This role determines its probability state. The basis for the determining of the entropy of object state based on a series of scientific and conceptual positions, developments of well-known scientists in connection with the problems of realization of physical processes. A mathematical model is proposed, that allows using the classical methods to determine the amount of information entropy and to use it to solve several problems: to choose the first preference structure with less uncertainty; to evaluate the behavior ("aging") of a system; to identify the problem areas of structures for the purpose of timely execution of equipment preventative maintenance; to construct the optimal system structure.
Mathematic simulation of the power interchange in the interbucket space of coaxially located impellers of the centrifugal turbo machine
Authors: Podbolotov Sergey , Kolga Anatoly , Dyorina Natalja
Published: October 2018

The article presents the results of mathematic simulation to determine the effect of geometric parameters, coaxially installed impellers, a centrifugal turbo machine on the developed pressure, depending on the mode of operation (frequency and relative direction of the impellers rotation). It is established that irrespective of the operation mode, the influence of the circumferential velocity, the ratio of the input and output diameters and the width of the impeller on the value of the pressure developed by the turbo machine is invariable. While the influence of the density of the blades system decreases with the counter rotation of the impellers.
Modeling of public transport waiting time indicator for the transport network of a large city
Authors: Lebedeva Olga , Kripak Marina
Published: October 2018

The need to develop and improve public passenger transport in major cities was noted. It was reflected that waiting time at bus stops is one of the factors that have a big impact on the passenger quality assessment of transport services. The results of an empirical study of the actual and anticipated waiting time at bus stops were given. It was noted that the reliability functions were used in the field of ride duration modeling, traffic restoration time after an accident, and length of making the decision to travel. The waiting time distribution functions using the lognormal function and the Weibull function were chosen. The results of modeling were objective, the dependent variables in it were the expected waiting time of passengers and the difference between the anticipated and the actual waiting time. The explanatory variables were sex, age, time period, purpose of the trip and the actual waiting time. The results of the research showed that the age, purpose of the trip and the time period influence the waiting time perception, prolong it and lead to its reassessment.
Analysis of the execution time of multi-stage control operations with multiple measurements
Authors: Kopp Vadim , Balakin Alexey , Balakina Natalya , Zamoryonov Mikhail
Published: October 2018

Questions related to the management of the process of multiple measurements are considered, depending on the result, which affects their number. In this case, the measurement time can be significantly increased. The above algorithm for controlling the measurement process justifies the random nature of the duration of its execution, which entails the need to study the time of carrying out multiple measurements. The paper constructs a semi-Markov model that allows to determine the distribution functions of time between events in the output flow of products after measurements, which makes it possible to dock this model with models of elements of higher levels of the hierarchy of the production structure. In the model, it is taken into account that some part of the production after a given number of measurements is defective and leaves the system. The constructed semi-Markov model allows to predict the performance of a technical system associated with multiple measurements.
Verification of the protective steam curtain model by means of experiment’s results
Authors: Nasibullin Rail , Valeyev Sergey , Galeyev Ainur
Published: October 2018

To protect the technological furnaces of the oil and gas industry from the penetration into their combustion zone combustible gases that are accidentally released at the production site, steam curtains are used. In the open press, there are practically no methods that allow to evaluate the efficiency of steam curtains, so the solution of this issue seems to be topical. In this paper, we checked the adequacy of the mathematical model developed by the authors of this article. This model describes the operation of the curtain, the movement of the vapor-gas cloud in space, and the scattering of the cloud by the curtain. The verification was carried out by comparing the results of the simulation with the results of laboratory experiments of third-party authors.
Experimental researches of plant protection means
Authors: Belousov Sergey V. , Belousova Anna I.
Published: October 2018

There was presented and investigated the problem of the application of atomizing tips in the system of processing plants with backpack sprayers in small forms of management and conditions of limited land use. Laboratory researches were conducted using the equipment of the company TeeJetTechnologies, namely for the work on the specified equipment there was designed the dispenser for the selection of atomizing tips of the present design of the sprayer. It will allow you to select atomizing tips for wider use. Also there were designed forms of tables to control the operation of the proposed sprayer based on the processing of one row.
Design of the universal agricultural working body and study of its parameters
Authors: Belousov Sergey V. , Pomelyayko Sergey A. , Novikov Vladislav V.
Published: October 2018

The article is devoted to the scientific approach with the help of computer-aided design tools for modeling the processes of interaction of tillage tools with soil. The article has an applied character, which is expressed in the fact that the method of computer-aided design in Mathcad using software CAD COMPASS 3D has been used. The analyses of expressions in the form of three-dimensional graphs are widely presented and their detailed review is given, which can be used to perform the improvement of the design of units that perform the main treatment of the soil with a turnover of a layer. As a result of the work done, there was obtained a combined plowshare with additional flat-cutting working bodies, there was made a matrix of experiment planning, there was obtained a graph of the dependence of the width grip of the flat-cutting razor on the speed of the arable unit. There were substantiated the factors of influence on performance as a result of using the planning of the two-factor experiment due to the orthogonal plan, there were determined the optimal settings of the operation modes of the plowshare.
Modernization of grinding machines of grain cleaning machines
Authors: Dorokhov Aleksey , Khamyev Victor , Lepeshkin Kirill
Published: October 2018

As a result of the analysis of developed earlier mathematical models of the process of seeds purification on a two-tier lattice mill of polymeric materials the possibility of significant improvement in the quality of seed treatment and performance at the same quality at the expense of more rational technological schemes and modernization of the sieve camp’s were revealed. Constructive changes were made in the lattice mill with using a new type of polymer sieves. Result of this experimental studies confirm the identified possibility of intensification of the process of seed cleaning - completeness of waste allocation increased from 0,653 to 0.75, i.e. 15 %, performance for the same quality of cleaning have increased by 24%.
Development of a set of working units from polymeric materials for the design of combine harvesters
Authors: Izmailov Andrey , Moskovskiy Maksim , Podlesniy Dmitriy
Published: October 2018

In this paper we presents the results of research on the use of new types of products from polymeric materials in the designs of combine harvesters. The use of these modernized polymer structures will reduce the damage of grain by more than 20%, increase the reliability of ongoing technological processes, increase the operational life of the combine.
Justification of the construction of a self-propelled selection seeder with an intelligent seeding system
Authors: Lavrov Alexander , Smirnov Igor , Litvinov Maksim
Published: October 2018

Aim of the state’s programs is development of selection and seed production in Russia. It is required researching related to the creation of new intelligent technical systems which implemented in techniques for selection, in particular in a self-propelled selection seeder. It is proposed to develop an intelligent seed sowing technology and it will be realize on the basis of a self-propelled selection seeder.
The determination of the single piece dispenser parameters
Authors: Smekhunov Evgeny , Chaika Evgeny , Gritsay Irina
Published: October 2018

Automatic processing of fruits, root crops, single-piece vegetables is complicated by the need of single object supplying with the guaranteed intervals between them into the control zone. There is a need to create the simple, reliable single-piece giving piece dispensers. The information and the attention of researchers and at this issue is not enough. The questions of justification of the parameters substantiation of the conveyor single-piece dispenser are considered. The main conveyor speed positions, shaft diameters, profile configurations, the ways of setting a tuber on the conveyor, etc. are tested experimentally. The conclusion of the possibility and expediency of using the roller version of the single-piece dispenser is made.
Analysis of the threshing process in the interriffle space of the threshing device
Authors: Fisunova Elena , Groshev Leonid , Baryshnikova Olga
Published: October 2018

By implementing a factor experiment in the laboratory the regularity of the change in the degree of threshing of ears in the space between the riffles of the flail’s threshing drum was stated. A mathematical model of the threshing process in the space between the riffles is given. The obtained results broaden the understanding of the nature of threshing by grinding in the threshing space of a combine harvester. The tests used unmilled ears of Donskaya ostistaya wheat, freed from grains by 70-80%. It is determined that the complete threshing is carried out for one impact of the flail and with minimal compression of the plant mass. Conclusions are made about the results obtained.
Automatization of settings of working organs of technological process of combine harvester
Authors: Tsarev Yuri , Adamcikova Elena , Najie Martin
Published: October 2018

The development of scientific and technological progress is currently in the direction of the introduction of electronic control systems that can help a human being in everyday affairs that does not require special creativity, for example, in unmanned driving, in aviation - the inclusion of an autopilot. The same happens in agricultural machinery. So in the modern harvester uses a system of precision agriculture, however, has reached the introduction of electronic systems that would regulate the optimum process flow of the operations, to take account of changing agricultural conditions on the field. Everything necessary for this purpose in combine harvesters is, it is electric and hydraulic drives that regulate the speed of the combine, the speed of rotation of the reel, the speed of rotation of the threshing unit, the speed of the fan, the amount of opening of the blinds, etc. However, now the combine operator sets it all manually. In the DSTU for several years as a program for on-Board computer (BC) and received a Patent for the invention, allowing to start the implementation of the process setup of the combine in automatic mode, but often the developer is easier to buy something abroad than to design and implement.
Leitliniengerechte Indikationsstellung der Herzschrittmacher- und ICD-Therapie
Authors: Schlichting Andrea , Gosau Nils
Published: October 2018

In 2016, there were 77 293 pacemakers and 28 953 ICDs implanted in Germany. This makes pacemaker- and ICD-implantations part of the most frequently performed operations in Germany. This article addresses questions of correct indication and patient selection.
Optische Kohärenztomografie
Authors: Schneider Hartmut , Ziebolz Dirk , Krause Felix , Häfer Matthias , Rüger Claudia , Haak Rainer
Published: October 2018

Mit Telematik und Technologien wie „Digitale Abformung“, „CAD/CAM“ oder „3-D-Röntgen“ hat die Digitalisierung die zahnärztliche Praxis längst erreicht. Den Wunsch nach effizienterer Diagnostik verfolgt dabei besonders das 3-D-Röntgen. Ein nichtinvasiv abbildendes Verfahren, dem wir erhebliches diagnostisches Potenzial zubilligen, ist die optische Kohärenztomografie. In diesem Beitrag werden Beispiele aus der Zahnerhaltung dargestellt, die ein breites Anwendungsspektrum dieser neuartigen Technologie auch in der Zahnheilkunde erwarten lassen.
Strahlenrisiko auf Langzeitraumflügen
Authors: Hellweg Christine E. , Berger Thomas , Baumstark-Khan Christa
Published: October 2018

Der alte Menschheitstraum, nach den Sternen zu greifen und den Fuß auf unbewohnte Planeten zu setzen, rückt für den heutigen Menschen in unmittelbare Nähe. Die technisch mögliche Reise zu Mond oder Mars kann für den „Homo spatialis“ mit Sonnenstürmen und Partikelbeschuss gepflastert sein und birgt medizinische Risiken: Vor allem die erhöhte Strahlendosis der solaren und galaktischen Komponenten der Weltraumstrahlung (Elektronen, Protonen und hochenergetische schwere Teilchen) kann zu einem bedrohlichen Gesundheitsrisiko werden. Je nach Missionsdesign besteht die Möglichkeit, durch unvorhersehbare Sonnenstürme akute Strahlenschäden zu erleiden und, bedingt durch die erhöhte biologische Wirksamkeit der galaktischen Strahlung, Langzeitschäden zu entwickeln. Abschätzungen zeigen, dass Astronauten während einer Marsreise mit einer Strahlenbelastung zu rechnen haben, die weit über dem amtlichen Grenzwert von jährlich 20 mSv für beruflich strahlenexponierte Personen in Europa liegt. Die Karrieredosis von Astronauten kann möglicherweise zu einem 3–4 % erhöhten zusätzlichen Krebsrisiko führen. Des Weiteren ist mit einem früheren und häufigeren Auftreten von Katarakten zu rechnen. Das Risiko für neurodegenerative Effekte ist zurzeit schwer einschätzbar. Gegenmaßnahmen umfassen Abschirmung, Warnsysteme für Sonnenstürme und unter Umständen auch diätetische und pharmakologische Mittel.
Medizinische Versorgung bei Langzeitmissionen in der Raumfahrt
Authors: Kerkhoff Steffen , Komorowski Matthieu , Schmitz Jan , Jansen Stefanie , Meyer Moritz F. , Warnecke Tobias , Hinkelbein Jochen
Published: October 2018

Im Lichte zukünftiger Langzeitraumfahrtmissionen fernab der Erdumlaufbahn besitzt die Fähigkeit der Crew zur autonomen, medizinischen Versorgung einen besonderen Stellenwert. Hier ist insbesondere die Durchführung einer Anästhesie bei einer dringend notwendigen Operation von entscheidender Bedeutung, um unter Umständen die Mission weiter fortsetzen zu können. Bisher musste noch keine Allgemeinanästhesie in der Raumfahrt durchgeführt werden, sodass die praktische Erfahrung entsprechend limitiert ist. Es erscheint sinnvoll, in Umgebungen mit vergleichbaren medizinischen Versorgungssituationen nach Erfahrungswerten und Behandlungsstrategien zu suchen. Diese Umgebungen sollten über eine oder mehrere der Eigenschaften von Raumfahrtmissionen verfügen. Beispielsweise könnten dies Limitationen bei medizinischem Personal und Ausstattung oder die Unmöglichkeit einer zeitnahen Evakuierung zu einer höherwertigen Versorgungseinrichtung sein. Die vorliegende Übersichtsarbeit fasst die bisher zu diesem Thema publizierte Literatur zusammen und gibt einen Überblick über wichtige und bisher bekannte medizinische Maßnahmen in Schwerelosigkeit.
Jahrestagung der dggö 2019 – Servus in Augsburg
Authors: Nuscheler Robert
Published: October 2018

2019 kommt die 11. Jahrestagung der Deutschen Gesellschaft für Gesundheitsökonomie (dggö) nach Augsburg: Die Tagung findet vom 18. bis 19. März 2019 auf dem
Campus der Universität Augsburg statt. Mit dem Tagungsthema „Gesundheitsverhalten und Prävention“ wird die Bedeutung individuellen Verhaltens und der
persönlichen Lebensumstände für die eigene Gesundheit ins Zentrum gerückt sowie die sich daraus ergebenden gesundheitspolitischen Implikationen.
Partizipative Entscheidungsfindung – Patientenpartizipation im Kontext der medizinischen Entscheidungsfindung bei Ekzemen
Authors: Potempa Christoph
Published: October 2018

Block J. Improving Value for Patients with Eczema. Value Health 2018; 21: 380–385

Die Autorin Block stellt in ihrem Artikel ein Zentrum zur partizipativen Entscheidungsfindung vor, dass die Patienten verstärkt in Behandlungsentscheidungen
integriert und ihnen eine aktive, gestaltende und dem Arzt gleichgestellte Rolle im Behandlungskontext einräumt. Die langfristigen Auswirkungen dieser
erhöhten Patientenpartizipation sind vielversprechend und mit schnelleren Heilungsraten sowie einer erhöhten Compliance und Lebensqualität der Patienten
verbunden.
Schwannoma plexiforme en eminencia tenar
Authors: Rodríguez Rodríguez Miriam , García Frasquet María Ángeles , Nieto Díaz de los Bernardos María Isabel
Published: October 2018

El schwannoma plexiforme es un tumor raro, que suele aparecer en tronco, cabeza y cuello. Su diagnóstico definitivo es anatomopatológico, siendo de especial relevancia su distinción con el neurofibroma plexiforme. No se ha descrito potencial de malignización y el tratamiento de elección es la extirpación quirúrgica. Presentamos el caso de un varón de 34 con una tumoración dolorosa en eminencia tenar derecha. Tras realizar RNM que sugiere hemangioma cavernoso, se interviene quirúrgicamente realizándose escisión de la tumoración, cuyo estudio histológico diagnostica de schwannoma plexiforme. A los 12 meses de la cirugía, el paciente se encuentra asíntomático, sin mostrar signos de recidiva o enfermedades asociadas.
Advanced Glycation End Products:Receptors for Advanced Glycation End Products Axis in Coronary Stent Restenosis: A Prospective Study
Authors: Pearce Colin , Islam Naorin , Bryce Robyn , McNair Erick
Published: October 2018

This study was aimed to correlate the pre- and 6-month postpercutaneous coronary intervention (PCI) serum concentrations of advanced glycation end products (AGE), soluble receptors for advanced glycation end products (sRAGE), AGE/sRAGE ratio, and serum malondialdehyde (MDA) levels with in-stent restenosis (ISR) among patients receiving either a drug-eluting stent (DES) or a bare-metal stent (BMS).In-stent restenosis remains as an adverse outcome following PCI. Sixty consecutive nondiabetic, Caucasian male patients, diagnosed with a non-ST-elevation myocardial infarction who received either a DES or BMS via PCI, were enrolled. Baseline levels of serum AGE, sRAGE, AGE/sRAGE ratios, MDA, and angiographic parameters were determined at stenting and at 6 months. Patients with and without ISR at 6 months were compared on both baseline and 6-month biomarker levels and within stent types.The pre-PCI serum AGE levels and AGE/sRAGE ratios were higher in ISR patients compared with non-ISR patients, while the pre-PCI and post-PCI serum sRAGE levels were lower in ISR patients compared with non-ISR patients. The pre and post-PCI levels of MDA were also higher in ISR patients. Comparing stent types, relative levels of MDA between those with and without ISR at the respective time points were similar, although changes between time points appeared type specific.Post-PCI ISR correlates with low serum values of sRAGE and high serum values of AGE, MDA, and AGE/sRAGE ratio which are present at stenting. The associations of baseline AGE, sRAGE, AGE/sRAGE, and MDA levels with ISR appear consistent between stent types.
Probability of Success in the Ophthalmology Residency Match: Three-Year Outcomes Analysis of San Francisco Matching Program Data
Authors: Siatkowski R. , Mian Shahzad , Cullican Susan , Green Laura , Sun Grace , Waxman Evan , Wayman Laura , Stoner Julie , Chen Xi , Feldon Steven ,   for the Association of University Professors of Ophthalmology
Published: October 2018

Objective To develop a probability model of matching into a US ophthalmology residency program using San Francisco Matching Program (SF Match) data.

Design Retrospective data analysis of de-identified application and matching data.

Participants Registrants for the 2013, 2014, and 2015 ophthalmology residency matches conducted by the SF Match.

Methods Descriptive statistics of candidates, comparison of continuous and categorical variables between matched and nonmatched candidates, and linear regression modeling were performed. A recursive partitioning method was used to create a probability of matching algorithm.

Main Outcome Measures Probability of successfully matching based on quantifiable candidate characteristics.

Results Over the 3-year period, 1,959 individuals submitted an average of 64 applications and received a mean of nine interview invitations. The overall match rate was 71%, with 78% matching at one of their top five choices. Successful matches were more likely to occur in US medical school graduates (78% vs 20%, p < 0.001) and applicants on their first attempt (76% vs 29%, p < 0.001). The association between matching and number of programs applied became negative with > 48 applications. Probability of matching was “high” (> 80%) among US graduates with a step 1 United States Medical Licensing Examination (USMLE) score >243 (regardless of number of programs applied to), a step 1 USMLE score of 231 to 243 who applied to at least 30 programs, and first-time applicants with a step 1 score >232. No international medical graduates or repeat applicants had a “high” probability of matching.

Conclusions Although advice must be individualized for each candidate, applicants for ophthalmology residency who fall into a “high” probability of matching group are likely to be successful with applications to 45 or fewer programs. Applying to 80 or more programs should be considered for international medical graduates and/or applicants who are previously unmatched. Modification of the match application data form may allow more detailed analysis of variables such as Alpha Omega Alpha or Gold Humanism Honor Society membership, research activity, and composite evaluation on a standardized letter of recommendation.
Importance of Individual Elements for Perineal Protection in Childbirth: An Interventional, Prospective Trial
Authors: Rasmussen Ole , Yding Annika , Lauszus Finn , Andersen Charlotte , Anhøj Jacob , Boris Jane
Published: October 2018

Objective To analyze the association between each element of a hands-on intervention in childbirth and the incidence of obstetric anal sphincter injuries (OASIS).

Study Design We conducted a prospective, interventional quality improvement project and implemented a care bundle with five elements at an obstetric department in Denmark with 3,000 deliveries annually. We aimed at reducing the incidence of OASIS. In the preintervention period, 355 vaginally delivering nulliparous women were included. Similarly, 1,622 nulliparous women were included in the intervention period. The association of each element with the outcome was estimated using a regression analysis.

Results The incidence of OASIS went down from 7.0 to 3.4% among nulliparous women delivering vaginally (p = 0.003; relative risk = 0.48; 95% confidence interval [CI]: 0.30–0.76). Number needed to treat was 28. Logistic regression analysis showed that using hand on the head of the child significantly reduced the risk of OASIS (odds ratio = 0.28; 95% CI: 0.14–0.58).

Conclusion Using a quality improvement framework, we documented the individual elements of the intervention. Hand on the infant's head reduced the risk of OASIS.
Laparoscopic Ventral Mesh Rectopexy: Functional Outcomes after Surgery
Authors: Ahmad Nasir , Stefan Samuel , Adukia Vidhi , Naqvi Syed , Khan Jim
Published: October 2018

Aims Rectal prolapse is a debilitating and unpleasant condition adversely affecting the quality of life. Laparoscopic ventral mesh rectopexy (LVMR) is recognized as one of the treatment options. The aim of this study was to evaluate the functional outcomes after a standardized LVMR.

Methods A cohort of patients who underwent LVMR from 2011 to 2015 were contacted and asked to fill questionnaires about their symptoms before and after the surgery. Three questionnaires based on measurement of Wexner fecal incontinence (WFI), obstructive defecation syndrome (ODS), and Birmingham Bowel and Urinary Symptom (BBUS) scores were used to assess the changes in postoperative functional outcomes. Some additional questions were also added to further assess bowel dysfunction.

Results There were 58 female patients with a mean age of 62.74 ± 15.20 (26–86) years in this cohort. About 70% of the patients participated in the study and returned the filled questionnaires. There was a significant overall improvement across all three scores (WFI: p = 0.001, ODS: p = 0.001, and BBUS: p = 0.001). Some individual components in the scoring systems did not improve to patient's satisfaction. No perioperative complication or conversion to an open procedure was reported in this study. Three recurrences were seen in the redo cases.

Conclusion LVMR is a promising way of dealing with rectal prolapse. A careful patient selection, appropriate preoperative workup, and a meticulous surgical technique undoubtedly transform the postoperative outcomes.
Besonderheiten des Kniegelenkersatzes beim Rheumatiker
Authors: Gaulke R.
Published: October 2018

Durch die zunehmende Spezialisierung in der operativen Versorgung der Erkrankungen des Bewegungsapparates besteht die Gefahr, dass Patienten mit Systemerkrankungen auf die biomechanischen Defizite des zu behandelnden Gelenkes reduziert werden. Insbesondere die Endoprothetik an Knie- und Hüftgelenk hat durch die Zertifizierung von sogenannten Endoprothesenzentren mit Hauptoperateuren, die nahezu ausschließlich Kniebzw. Hüft-Endoprothesen implantieren, zu einer starken Gewichtung der Operationstechnik im Hinblick auf biomechanische Erfordernisse geführt. Bedauerlicherweise treten die Nebenerkrankungen, die den Verlauf nach der Implantation einer Endoprothese maßgeblich beeinflussen können, hierbei häufig in den Hintergrund. Die stetige Markteinführung neuer Immunsuppressiva mit unterschiedlichen Halbwertszeiten erfordert jedoch dringend, dass bei der Implantation einer Endoprothese die Medikation entsprechend pausiert werden muss, um das Infektionsrisiko so gering wie möglich zu halten. Daneben bestehen beim Rheumatiker besondere Risikofaktoren fernab des zu operierenden Gelenkes, welche unter Umständen zu letalen Komplikationen führen können.
Remote state preparation using Einstein–Podolsky–Rosen representations
Authors: Huang Siendong
Published: October 2018

Because Einstein–Podolsky–Rosen states are well-defined on the Weyl algebra, their canonical cyclic representations are suitable for demonstrating the process of remote state preparation. Local projection-valued measurements and the corresponding recovery unitary operator are formulated in this representation, whereupon generalized equatorial states are prepared remotely and faithfully.
Progress on next generation gamma-ray Cherenkov detectors for the National Ignition Facility
Authors: Herrmann H. W. , Kim Y. H. , Zylstra A. B. , Geppert-Kleinrath H. , Meaney K. D. , Young C. S. , Lopez F. E. , Fatherley V. E. , Pederson B. J. , Oertel J. A. , Hernandez J. E. , Carrera J. , Khater H. , Rubery M. S. , Horsfield C. J. , Gales S. , Leatherland A. , Hilsabeck T. , Kilkenny J. D. , Malone R. M. , Batha S. H.
Published: October 2018

Fusion reaction history and ablator areal density measurements for Inertial Confinement Fusion experiments at the National Ignition Facility are currently conducted using the Gamma Reaction History diagnostic (GRH_6m). Future Gas Cherenkov Detectors (GCDs) will ultimately provide ∼100x more sensitivity, reduce the effective temporal response from ∼100 to ∼10 ps, and lower the energy threshold from 2.9 to 1.8 MeV, relative to GRH_6m. The first phase toward next generation GCDs consisted of inserting the existing coaxial GCD-3 detector into a reentrant well which puts it within 4 m of the implosion. Reaction history and ablator gamma measurement results from this Phase I are discussed here. These results demonstrate viability for the follow-on Phases of (II) the use of a revolutionary new pulse-dilation photomultiplier tube to improve the effective measurement bandwidth by >10x relative to current PMT technology; and (III) the design of a NIF-specific “Super” GCD which will be informed by the assessment of the radiation background environment within the well described here.
A jump in temperature gradient induced by the transition from density-gradient to temperature-gradient driven mode in L-mode edge
Authors: Kim J. Y. , Han H. S.
Published: October 2018

Motivated by a recent work [J. Y. Kim et al., Phys. Plasmas 24, 042503 (2017)], a more detailed study is presented on the transition process from the density gradient to temperature gradient driven one in L-mode edge-like plasmas. Based on an approximate estimate of the turbulent heat flux using the simple mixing length formula, with an assumed form of density profile evolution, it is shown that a jump in the temperature gradient can occur during the transition to meet the power balance. The possible connection of this mechanism to the confinement improvement in temperature, observed in the low to improved mode (L-I) transition, is discussed.
High magnetic field sensitivity in anti-ferromagnetically coupled 001-epitaxial [Co2Fe(Al0.5Si0.5)/Ag]N multilayers
Authors: Shiroyama T. , Sakuraba Y. , Nakatani T. , Sepehri-Amin H. , Jung J. W. , Hono K.
Published: October 2018

We have investigated the effects of the number of repetition (N) of ferromagnetic/nonmagnetic bilayers on the magnetic property and current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) in [Co2Fe(Al0.5Si0.5) (CFAS)/Ag]N multilayer for a potential magnetic field sensor application. The antiferromagnetic interlayer exchange coupling (AFM-IEC) between CFAS layers through the Ag(2.1 nm) spacer realized an anti-parallel magnetization configuration between the adjacent CFAS layers with N up to 6, which led to the stable linear response of magnetoresistance (MR) against a magnetic field in the range of 60-70 mT. The resistance change-area product (ΔRA) and the MR ratio were monotonically increased with N from 6.6 mΩ μm2 and 16% for N = 1 (CFAS/Ag/CFAS trilayer) to 23 mΩ μm2 and 43% for N = 6, respectively, giving an enhancement of field sensitivity with N up to 4.5%/mT. We also found nearly 3 times smaller non-linearity (1.2% Full Scale) in the device with N = 6 compared to that with N = 1. This study suggests a potential of Heusler-alloy based multilayer CPP-GMR device having AFM-IEC for magnetic field sensor applications.
A structural subgrid-scale model for relative dispersion in large-eddy simulation of isotropic turbulent flows by coupling kinematic simulation with approximate deconvolution method
Authors: Zhou Zhideng , Wang Shizhao , Jin Guodong
Published: October 2018

A kinematic simulation with an approximate deconvolution (KSAD) hybrid model is proposed to predict the Lagrangian relative dispersion of fluid particles in a large eddy simulation (LES) of isotropic turbulent flows. In the model, a physical connection between the resolved and subgrid scales is established through the energy flux rate at the filter width scale. Due to the lack of subgrid-scale (SGS) turbulent structures and SGS model errors, the LES cannot accurately predict the two- and multi-point Lagrangian statistics of the fluid particles. To improve the predictive capability of the LES, we use an approximate deconvolution model to improve the resolved scales near the filter width and a kinematic simulation to recover the missing velocity fluctuations beneath the subgrid scales. To validate the proposed hybrid model, we compare the Lagrangian statistics of two- and four-particle dispersion with the corresponding results from the direct numerical simulation and the conventional LES. It is found that a significant improvement in the prediction of the Lagrangian statistics of fluid particles is achieved through the KSAD hybrid model. Furthermore, a parametric study regarding the wavenumbers and orientation wavevectors is conducted to reduce the computational cost. Good results can be obtained using a small number of wavenumber modes and orientation wavevectors. Thus, we can improve the prediction of the Lagrangian dispersion of fluid particles in the LES by applying the KSAD hybrid model at an acceptable computational cost.
Revealing the stability, elastic properties and electronic structures of Pd-V intermetallics via first principle calculations
Authors: Zhou YunXuan , Yan Pei , Chong XiaoYu , Feng Jing
Published: October 2018

Precious metals and their alloys are promising high-temperature materials due to the high melting point, high strength and thermodynamically stability, in which Pd-V alloys are one kind of important systems. However, the influence of V concentration on structure stability, mechanical and thermodynamic properties and chemical bonding of Pd-V compounds is unknown. The structures, elastic properties, anisotropic of elastic and electronic structures of thirteen Pd-V compounds as a function of V concentration have been investigated by first principle calculations in this work. We have determined all the possible stable phases of Pd-V system for the first time by thermodynamics convex hull and phonon spectrum. The calculated results show that α-Pd2V has the lowest formation enthalpies as -0.34 eV/atom, indicating more thermodynamically stable than other structures. The elastic constants, bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio of the Pd-V compounds are also calculated and the β-Pd3V has the largest shear modulus and Young’s modulus as 107.1 GPa and 275.7 GPa, respectively. The anisotropic mechanical properties of these Pd-V compounds are discussed in detailed by the anisotropic index, three-dimensional (3D) surface contours and the planer projections on (001) and (110) planes of the Young’s modulus. The values of total density of states (TDOS) of all compounds are nonzero at Fermi energy (EF), indicating metallic feature for all the Pd-V compounds.
Low-voltage operation and high endurance of 5-nm ferroelectric Hf0.5Zr0.5O2 capacitors
Authors: Kim Si Joon , Mohan Jaidah , Kim Harrison Sejoon , Lee Jaebeom , Young Chadwin D. , Colombo Luigi , Summerfelt Scott R. , San Tamer , Kim Jiyoung
Published: October 2018

In this letter, the ferroelectric (FE) properties of 5-nm-thick Hf0.5Zr0.5O2 (HZO) films deposited by atomic layer deposition have been investigated. By reducing the HZO film thickness to 5 nm, low-voltage operation (1.0 V) of the HZO-based capacitor was achieved while maintaining a remnant polarization (Pr) of about 10 μC/cm2 (i.e., 2Pr of 20 μC/cm2). Meanwhile, in order to form an orthorhombic phase, which is responsible for FE properties, a rapid thermal annealing process was performed after TiN top electrode deposition. The FE properties were realized after low temperature annealing (450 °C for 1 min), making them compatible with the back-end of the line. In addition, the low operating voltage and the suppression of an additional monoclinic phase formation by stress-induced crystallization induced a robust endurance (>1010 cycles at 1.2 V) of the 5-nm-thick HZO sample.