bluuebunny/crossref_metadata_2025 huggingface dataset:
On the issue of involving abandoned agricultural land in crop rotation
Authors: Nizkiy Sergei , Muratov Aleksei
Published: November 2020

In the nineties of the last century due to the known economic stress experienced in this time in Russia there were more than fifty million hectors of arable lands withdrawn from the Russian agricultural turnover. There are more than one million hectors of such arable deserted lands in the Amur Region of the Russian Federation (The Far Eastern part of Russia). These arable lands have turned into deteriorating lands in abeyance being colonized by weeds and periodically attacked by fires. As a result of this, these promising agricultural lands, being used for the food supply and forage resources production, have lost their primary purpose of use. It has become a serious national economic problem. Nowadays there is a gradual inclusion of such arable lands into soya and wheat production. The conduction of agrochemical and geo-botanical research needed for suitability evaluation of such arable lands for soya and wheat species cultivation is to a certain degree very expensive and time-consuming procedure. Our research work suggests implementing resources-evaluating method which implies one-time route study in the period of mass flowering of plants and identifying the plants of the arable lands that have resource value. If the number of these plants exceeds eighty percent in relation to the whole species composition, then such arable lands are considered to be suitable for crop rotation. If this ratio is less than sixty percent, then it is necessary to take extra measures in order to reduce the number of weeds and woody plants on such arable lands.
The emergence and development of mycoses in short-day plants under conditions of long daylight hours
Authors: Podkovyrov Igor , Kimsanbaev Oybek , Zhemchuzhina Natalya , Ermak Dmitry , Ilyusinova Laura , Nasonova Tatiana
Published: November 2020

The relevance of the study of mycoses is increasing due to their widespread distribution. Field experiments were carried out on sites in the region with short daylight hours (Dagestan) and long daylight hours (Volgograd). Fungal diseases were investigated on crops with short daylight hours: cucumber, pepper, and cotton according to the methods generally accepted in phytopathology. The species composition of aboriginal and exotic infections was revealed. Each culture under conditions of long daylight hours is characterized by damage by 4-5 species of fungi. The manifestation of exotic infections is observed at the beginning of the growing season at the seedling stage. The role of the introduction of short-day plants to the northern regions in the spread of exotic species of pathogenic fungi is shown. The species composition of fungi on crops in the study areas was found to be identical. They belong to different biological groups, but saprotrophs, biotrophs and hemibiotrophs predominate. It was found that Fusarium lolii (Wm.G. Sm.) Sacc and Rhizoctonia solani Kuehn (on cotton) and Verticillium dahliae Kleb and Rhizoctonia solani J.G. moved to new areas together with seeds. Kuhn (on pepper). These species are capable of causing epiphytotics at the beginning of the growing season with a low natural infectious background. The accumulation of native species of infection in the lands adjacent to the fields during the cultivation period leads to the appearance of epiphytoties in the second half of the growing season. First of all, the assimilation apparatus, flowers, ovaries and fruits are affected.
Study of the parameters and operating modes of the installation for aerosol treatment of seed grain
Authors: Teterin Vladimir , Terentyev Vyacheslav , Andreev Konstantin , Shemyakin Alexander , Teterina Olga
Published: November 2020

One of the modern elements of agrotechnologies is the presowing treatment of seeds with bio-stimulating preparations, providing a complex effect on seeds, which, along with improving the sowing and productive qualities of seeds, can increase the resistance of plants to adverse environmental factors, diseases and pests. Recently, world agricultural production is increasingly focused on environmentally friendly technologies, where preparations based on components of natural origin become important. Preparations based on humic acids are among them. The effectiveness of their use in the process of presowing treatment of seeds to a certain extent depends on the technology and technical means used. This article discusses the design of the developed seed dresser and explores the basic physical processes that affect the quality of seed treatment. The effectiveness of seed treatment with growth stimulants has been studied depending on the intensity of heat exchange processes taking place in the processing chamber of the developed device, where heat transfer from the vapor of humates to the downward flow of grain occurs. Herewith, the dependence of heat transfer on the residence time of the grain in the treatment chamber, heat carrier temperature (aerosol of humates) and uniform distribution of coolant flow in the treatment chamber was determined.
Treatment of electroplating wastewaters
Authors: Belova Larisa , Vialkova Elena , Glushchenko Ekaterina , Burdeev Viacheslav , Parfenov Yuriy
Published: November 2020

In this article, the specificity of wastewaters formed at electroplating plants and problem of its treatment is considered. The purpose of this research is to suggest the technological scheme of wastewater treatment, for one of the typical electroplating plants. Standard research methods were used: gravimetrical, photometrical and fluorimetrical methods of liquid analysis to achieve this goal. This article presents the method of electroplating wastewater treatment, based on chemical precipitation, including addition of the various reagents for removing heavy metals from the effluents. Because of the laboratory research, the effects of pollutants removal are 91% (total iron) and 94.6% (suspended solids). These effects were achieved by the technological scheme that includes averaging and mixing several technological effluents, their chemical precipitation with NaOH, Ca(OH)2 and flocculant during an hour.
Corporate criminal liability on environmental crimes in Vietnam
Authors: Dinh Thi Mai , Dinh Ngoc Thang , Bui Thi Phuong Quynh , Nguyen Anh Duc
Published: November 2020

From 00:00 on January 1, 2018, all environmental criminal acts of commercial entities are prosecuted for criminal liability. In order to investigate criminal liability for corporate legal entities, up to now, Vietnam have Criminal Code 2015, Criminal Procedure Code 2015 and Law on Execution of Criminal Judgment 2019. However, the competences, order and procedures of judgment excution for corporate legal entities that environmental commit crimes are still controversial and has been urgently discussed. The Penal Code 2015 on corporate legal entities has been in effect for nearly 5 years, but in fact up to July 2020, there has not been a commercial entity prosecuted and tried or excuted yet. The difficult problem is the penalties applied to legal entities different in the nature, order, procedures and ways of conducting compared with individual. This paper introducing the new regulations about the criminal liability on corporate entities for environmental crimes in Vietnam Criminal Code 2015 and analyze and point out some challenges, proposes some suggestions in Vietnam execution of criminal judgments.
Improving the properties of frozen shrimp by improving the characteristics of the surface ice glaze
Authors: Duborasova Tatyana , Kolobov Stanislav , Osipenko Elena
Published: November 2020

Research work was carried out on the introduction of various food additives in the icing of raw-frozen shrimp. This allowed us to pre-serve the quality indicators of shrimp, as well as to increase the shelf life from 4 months. up to six months.
Substantiation of technological approaches to creation of a functional product based on creamy pumpkin composition
Authors: Bibik Irina , Luchay Alexander , Dotsenko Sergey
Published: November 2020

Scientific research and practice show that a certain part of the population of the Russian Federation has nutritional disorders. In particular, the deficiency in β-carotene is within 20%, vitamin C - 25%, iron - 35%, zinc - 35 - 45%. The analysis found that on the basis of widespread raw materials of plant origin and, in particular, carotene-containing, it is possible and advisable to create functional products containing a complex of vitamin and mineral substances with a synergistic (strengthening) effect. At the same time, the assumption was used about the possibility and feasibility of extracting β-carotene from pumpkin pulp by the fatty component of cream with a mass fraction of fat from 10% to 20%. Taking into account this approach, a basic technological scheme for obtaining food systems enriched with β-carotene has been developed. On the basis of the cream and pumpkin composition obtained according to one of the options, the recipe for the dessert chocolate paste “Armeyskaya” was developed. The possibility and expediency of creating a mayonnaise product with a relatively high protein content, a rational ratio of polyunsaturated fatty acids, as well as significant concentrations of vitamins has been substantiated. Rheological dependences and consumer properties of a mayonnaise product with a given physiological effect have been established. It was found that it contains an antioxidant complex: β-carotene + vitamin C + Zn, which has a synergistic effect. It makes it possible to recommend the product as having the effect of maintaining the activity of the cardiovascular system in accordance with the Russian national standard GOST R-54059-2010.
Optimal parameters and modes of extraction of biologically active substances from natural fruit and berry raw materials
Authors: Mironova Elena , Romanenko Elena , Sycheva Olga , Selivanova Maria , Esaulko Natalia
Published: November 2020

Vegetable raw materials serve as a source of a large number of organic compounds of various structures with a variety of preventive and curative nutritional properties. The article presents the results of a study on the establishment of parameters and modes of extraction of biologically active substances from fruit and berry raw materials in order to obtain extracts for the preparation of functional beverages. The work was carried out on the basis of the educational and scientific laboratory of technology of winemaking and food from vegetable raw materials of the Stavropol State Agrarian University according to generally accepted methods in accordance with GOST (State standards). When preparing the extracts, water treatment of the crushed mass of feijoa and blackberries was used. The extraction process was controlled by changing the mass fraction of dry substances. As a result of the research, the optimal conditions for the process of extracting dry substances from feijoa and blackberries were established: hydromodule – 1:1, the duration of the process – 24 hours; the extraction temperature is 25 degrees C. Such conditions of the process provided the greatest extraction of dry substances without destroying the functional ingredients, allowed the extraction to be carried out within a short period of time and reduced the cost of temperature treatment of the medium. The paper presents the results of tasting evaluation of the obtained extracts.
Influence of high hydrostatic pressure on the optical properties of minced fish proteins
Authors: Drobotko Valeriy , Bukin Gennadiy , Sokolov Sergey , Yashonkov Alexander , Falko Alexander
Published: November 2020

In the functioning of various biological systems, an extremely important role is played by the dynamic properties of optically anisotropic protein macromolecules, such as translational movements, temporal correlations, and transfer processes, which are determined by the surface charge, molecular weight, molecular shape, and the nature of intermolecular interactions. An experimental study of the influence of high hydrostatic pressure on the optical properties of pike perch minced fish proteins at room temperature was carried out in this work. The intensities of the radiation transmitted through a thin plane-parallel layer of minced fish were measured, which was subjected to hydrostatic compression at a rate of ≈3 MPa/s and ≈17 MPa/s. It was found that with increasing pressure, the intensity of the transmitted light decreases nonmonotonically; in this case, the experimental plots of the I(P) dependence show the presence of broad attenuation bands of the intensity of the radiation transmitted through the sample, located at pressures of about 150, 300, and 700 MPa. The observed attenuation bands are associated with the appearance of scattering centers formed as a result of denaturation of macromolecules of proteins of various types with different functional purposes contained in the muscle tissue of pike perch.
Innovative-oriented development of AIC complex as an economic priority development vector of the Far Eastern Federal District
Authors: Pashina Lyubov , Pastushenko Svetlana , Reimer Valerii
Published: November 2020

The transition of the agro-industrial complex of the Far Eastern Federal District to innovative-oriented development objectively enforces the activation of innovative and investment processes, as well as ensuring effective management of innovative development as a single complex of interrelated economic processes. The specific territorial zoning of the region’s AIC requires differentiation of the innovative development strategies of its individual sectors in accordance with the certain conditions of their functioning. The research is based on the study and generalization of scientific approaches to the issues of innovative-oriented development of the AIC, taking into account various factors: territoriality, zonality, economic potential, etc. The article formulates a set of provisions underlying the development of the innovative-oriented development concept of the AIC of the region. There was determined the set of strategic goals of its innovative development regarding the specifics of the subjects. The purpose of research is to develop a conceptual approach to innovative-oriented development of AIC of the region, in appliance with its specifications.
Impact of the spread of epidemics, pandemics and mass diseases on economic security of transport
Authors: Chernogor Nikolay , Zemlin Alexander , Kholikov Ivan , Mamedova Irada
Published: November 2020

The problem of the spread of the coronavirus epidemic is now being widely discussed not only in the media, but also in legislative and executive authorities, business and scientific circles around the world, including in Russia. The article provides a brief overview of the main epidemics that occurred in modern world history, their impact on the economy of individual countries and the world economy as a whole. The main attention is paid to the analysis of the impact degree of epidemics and pandemics on the transport sector of the economy. The specificity of the impact of the spread of mass diseases on the functioning of transport system and its’ economic security is shown. Possible directions of organizational and legal support for the activities aimed at minimizing the consequences of the pandemic on the economic security of transport are substantiated.
Modelling of state support for biodiesel production
Authors: Zhichkin Kirill , Nosov Vladimir , Zhichkina Lyudmila , Panchenko Vladimir , Zueva Elena , Vorob’eva Darya
Published: November 2020

Government support for the development of biofuel production is a relevant part of the system of budget regulation of agricultural production in the Russian Federation. Currently, there is no sound financing method for mechanisms of state regulation of biofuel production which impedes impartial allocation of funds and makes this procedure non-transparent and not motivated enough. In view of this situation, a mathematical economic model was developed that allows one to calculate the optimum level of government support for every type of biofuel considering main areas of state support. We propose to consider three scenarios for the determination of the optimum level of public funding. The first one allows for optimization of the level of government support considering sizes of agricultural production for the i-th crop to provide farms of the region. The second scenario suggests the determination of the maximum profit from the biofuel production through increased agriculturally used areas. Finally, the third one considers calculation of the minimum expenses of achieving the volume of production that provides the farm with raw materials. According to the first scenario, the optimum level of government support for the field should be 1163.6 million rubles. In the implementation of the second scenario in the Samara region, the agriculturally used area planted with oil crops should be increased by 47.1 thousand ha.
Twin relationship in between the variant-pair of η precipitates in the Al-Zn-Mg-Cu aluminium alloy
Authors: Chung Tsai-Fu , Yang Yo-Lun , Hsiao Chien-Nan , Li Wei-Chih , Yang Jer-Ren
Published: November 2020

For Al-Zn-Mg-Cu aluminium alloys, 15 types of η precipitates would possess the symmetrically variants distributed on the closed planes of the Al matrix, parallel to the (0001)η, (21̅1̅0)η, or (101̅0)η interfaces of precipitates. The η2 precipitates, possessing the crystallographic orientation of (111̅1̅)al // (0001)η2 and [110]al // [101̅0]η2, would exhibit four equivalent variants, i.e., η2(1)to η2(4), on the (11̅1̅)al habit planes. In the present work, along the zone axis of [110]al // [101̅0]η, the edge-on configurations showing the twin-like atomic arrays would occur as the growth/coalescence of two η2 variants grown on (111̅1̅)al and (11̅1)al planes, respectively. The twin relationship can be revealed in term of the crystallographic relationship at 70.5° with respect to their habit planes. Alternatively, on the (11̅1̅0)al image, it also indicates the nearly-twinning configuration in between the variant-pair of η2.
Using Artificial Intelligence to Aid Vehicle Lightweighting in Crashworthiness with Aluminum
Authors: Kohar Christopher P. , Connolly Daniel S. , Liusko Timofei , Inal Kaan
Published: November 2020

Significant efforts have been made in the automotive industry to reduce vehicle weight in order to improve vehicle fuel economy and reduce greenhouse gas emissions. New innovations in structural lightweight alloys and manufacturing techniques have allowed automakers to replace conventional steel with lighter aluminum structures. However, automakers have an enormous number of material and gauge thickness combinations to consider in the development process of the next generation production vehicle. Furthermore, the design combination of these materials and structures must not compromise the integrity of the vehicle during a vehicle collision. With the proliferation of inexpensive computational resources, automakers can now explore the effect of material selection on the crashworthiness of next-generation vehicles using computer simulations. While information from these simulations can be manually extracted, the vast amount of data lends itself to artificial intelligence (AI) techniques that can extract knowledge faster and provide more useful interpretations that can be convenient for designers and engineers. This work presents a framework for using artificial intelligence to aid the vehicle design cycle in crashworthiness using aluminum. Virtual experiments of a frontal crash condition of a pick-up truck are performed using finite element analysis to generate the data for this method. Different commercially available aluminum alloys and gauge thicknesses are varied in the virtual experiments. An advanced type of recurrent neural network is used to predict the time-series response of the occupant crash-pulse response, which is a key crashworthiness metric that is used for evaluating safety. This work highlights how automotive designs and engineers can leverage this framework to accelerate the development cycle of the next-generation lightweight vehicle.
Effect of ceramic particles on precipitation in an Al-Mg-Si alloy with silicon excess during ageing
Authors: Meyruey Gwenaëlle , Massardier Véronique , Perez Michel
Published: November 2020

Providing a good balance between lightweight and high mechanical properties, the aluminum-based metal matrix composites (MMC) became an interesting alternative for specific industrial applications. However, considering an Al-Mg-Si alloy with a high silicon excess, the ceramic particles added as reinforcement can act on : i) the precipitation kinetics of the coherent and semi-coherent phases, ii) the precipitation sequence of the alloy and iii) the loss of mechanical strength from a peak-aged microstructure obtained by a T6 condition. In order to understand the influence of reinforcement on these aspects, the composite was characterized during isothermal ageing between 100°C and 350°C, allowing us to propose an experimental Isothermal Transformation Curve. Compared to the unreinforced alloy, heterogeneous precipitation of disordered semi-coherent phases occurs on dislocations and the precipitation kinetics were found to be accelerated in the composite leading to an acceleration of the loss of strength from the T6 state, due to the precipitation of the Type-C phase. A study performed on a deformed alloy, demonstrated that the most of the differences observed between the unreinforced alloy and the composite can be explained by the high dislocation density generated in the matrix of the composite due to the presence of ceramic particles. Finally, the JMAK approach turned out to be a powerful tool to model the decrease in mechanical strength occurring during isothermal treatments from T6 state.
Ultrasonic processing of aluminium alloys above the liquidus: the role of Zr
Authors: Eskin Dmitry
Published: November 2020

Ultrasonic melt processing (USP) is gaining quite an interest in recent years due to the benefits of this technology to the melt quality and structure refinement. A number of mechanisms have been identified that govern the effects of USP at different stages of melt processing. Technologically it is advantageous to apply USP to the fluid melt rather than to a mushy solidifying alloy. In this case heterogeneous nucleation on available or activated/multiplied substrates is the main mechanism. Among these substrates, primary crystals of Al3Zr phase were shown to be potent and effective. This paper gives a review of the own research into the role of Al3Zr in structure refinement in various groups of Al alloys, from solid-solution type to hypereutectic. This overview includes the evidence of a possible eutectic reaction between Al and Al3Zr in Al-rich alloys, mechanisms of Al3Zr formation and refinement under USP (that enables these primary crystals to be active substrates for Al and some other primary phases), the role of USP in facilitating primary solidification of Al3Zr in the Al-Zr system, and the additional benefits of solute Ti presence. The paper is illustrated with the data obtained over the last 15 years of research led by the author.
Microstructure and mechanical properties of high-manganese-containing high-speed twin-roll cast Al-Mn-Si alloy strips and their cold-rolled sheets
Authors: Nguyen T.Ha , Song Ram , Harada Yohei , Muraishi Shinji , Kumai Shinji , Maruno Shun , Yoshino Michihide , Iwao Shohei
Published: November 2020

Al-Mn based alloys with high-manganese content are expected to have improved mechanical properties due to solid solution hardening and/or dispersion hardening. However, the increase of Mn solubility of the alloy is difficult by using the conventional DC casting. In order to solve this problem, in the present study, we focused on the twin-roll casting method which is characterized by high cooling rates. Several kinds of high Mn-containing Al-Mn-Si alloy strips were fabricated by using a vertical-type high-speed twin-roll caster equipped with a pair of water-cooled copper rolls. Direct temperature measurement of the liquid melt during the casting was also performed. The alloy strips of various compositions containing up to 4 Mn and 2 Si (wt%) were successfully obtained. By observing the microstructure of the cross section of the strip, we found the characteristic solidified structure. The solidified structure consisted of three layers. Two solidified shells with a columnar dendrite structure grew from the roll surfaces toward the strip center. In the mid-thickness region, the band structure consisting of equiaxed dendrites and globular grains was observed between the solidified shells. Very fine primary particles were observed in the matrix near the strip surface, while, relatively coarse particles with blocky and needle-like shape were observed in the central band of the as-cast strip. The electric conductivity measurement was performed for the as-cast strips. Mn solubility in Al matrix was estimated from the obtained values. The estimated Mn solubility in the Al-2Mn-xSi strips was between 1.5 ~ 1.8wt% Mn. It was over 1.43wt%Mn for the Al-4Mn-xSi strips. We found that the Mn solubility of the as-cast strips was considerably high. The strips were cold-rolled to the sheets and then annealed at various conditions. They were subjected to the tensile tests, and the effects of solid solution hardening and dispersion hardening are discussed.
Lifetime assessment of the process-dependent material properties of additive manufactured AlSi10Mg under low-cycle fatigue loading
Authors: Fischer Carl , Schweizer Christoph
Published: November 2020

Systematic low-cycle fatigue (LCF) experiments are carried out on additive manufactured AlSi10Mg specimens for several material conditions with varying layer thickness, heat treatment, building direction and surface quality. The deformation behaviour depends significantly on the heat treatment. It is outlined that the process control and heat treatment can produce fatigue properties comparable with the cast material, whereby an as-built specimen surface leads to a lifetime reduction in all cases. The experiments are accompanied with detailed metallo- and fractographic investigations. For all tested LCF specimens, the defect type and the failure origin defect size are characterized in terms of the √area parameter by using scanning electron microscopy. The failure of the specimen is mostly caused by lack of fusion surface or near-surface defects, whereby the defect size is determined by the SLM process parameters, such as building direction, surface quality and layer thickness. On the basis of the experimental data and the observed defects, a mechanism-based, deterministic lifetime model is developed and adapted to the specific damage mechanisms of the additive manufactured AlSi10Mg alloy.
Similarity and dissimilarity of joint interface morphology in magnetic pulse welded Al/Cu and Al/Ni plates
Authors: Kimura Shingo , Muraishi Shinji , Kumai Shinji
Published: November 2020

A characteristic wavy morphology often appears at the joint interface of magnetic pulse welding (MPW), and an intermediate layer is formed in some metal combinations. It has been known that the wavy morphology changes mainly depend on the density difference between the metals. A sinusoidal wavy interface is formed for the combination of similar metals (Al/Al, Cu/Cu) and that of dissimilar metals having almost the same density (Cu/Ni). In contrast, a trigger-like wavy interface is formed for the combination having a large density difference (Al/Cu, Al/Fe). The difference in strength (hardness) of the solid metal is also assumed to affect the wavy interface morphology. In the present study, two metal combinations (Al/Cu and Al/Ni) were subjected to the MPW to elucidate the effect of hardness difference, since Cu and Ni have almost the same density, but different hardness. Both the MPWed Al/Cu and Al/Ni joints showed a trigger-like wave interface. The wave size (wave-height and wavelength) of Al/Ni was smaller than that of Al/Cu. In Al/Ni, the distribution of intermediate phase was more continuous tracing the outline of the wave. The numerical simulation of the wave formation process was performed using the Smoothed Particle Hydrodynamics (SPH) method. It was revealed that the extent of metal jet penetration into the metal in the process of joining behind the collision point was weaker in Ni than in Cu. This is considered to be due to the larger deformation resistivity of Ni, which is harder than that of Cu.
Development of laser welding of high strength aluminium alloy 2024-T4 with controlled thermal cycle
Authors: Demirorer Mete , Suder Wojciech , Ganguly Supriyo , Hogg Simon , Naeem Hassam
Published: November 2020

An innovative process design, to avoid thermal degradation during autogenous fusion welding of high strength AA 2024-T4 alloy, based on laser beam welding, is being developed. A series of instrumented laser welds in 2 mm thick AA 2024-T4 alloys were made with different processing conditions resulting in different thermal profiles and cooling rates. The welds were examined under SEM, TEM and LOM, and subjected to micro-hardness examination. This allowed us to understand the influence of cooling rate, peak temperature, and thermal cycle on the growth of precipitates, and related degradation in the weld and heat affected area, evident as softening. Although laser beam welding allows significant reduction of heat input, and higher cooling rates, as compared to other high heat input welding processes, this was found insufficient to completely supress coarsening of precipitate in HAZ. To understand the required range of thermal cycles, additional dilatometry tests were carried out using the same base material to understand the time-temperature relationship of precipitate formation. The results were used to design a novel laser welding process with enhanced cooling, such as with copper backing bar and cryogenic cooling.
William Harvey réinterprété à la lumière de l’évolution des espèces (I)
Authors: Michel Jean-Baptiste
Published: November 2020

Au commencement est la pompe cardiaque qui produit un flux sanguin cyclique (énergie cinétique, Ek). En 1619, William Harvey (1578-1657) décrit expérimentalement, en utilisant des garrots veineux ou artériels, l’anatomie fonctionnelle de la circulation sanguine chez l’homme, à l’exception de la circulation capillaire. Pour la première fois est décrite la circulation sanguine en deux circuits fermés parallèles, l’un à haute pression, l’autre à basse pression. Marcello Malpighi (1628-1694) la complète par l’observation en microscopie du réseau capillaire. Un siècle plus tard, apparaissent les premières hypothèses sur l’évolution des espèces. Jean-Baptiste Lamarck (1744-1829) propose en 1809 une théorie de transmission évolutive des caractères phénotypiques par adaptation aux contraintes environnementales. En 1859, Charles Darwin (1809-1882) élabore une théorie de la sélection naturelle. L’interprétation qui prévaut actuellement intègre à la fois la génétique et l’épigénétique dans la transmission intergénérationnelle, et dans la dynamique de développement des caractères phénotypiques individuels, en particulier chez l’homme.
La saga de l’induction neurale : presque un siècle de recherche
Authors: Moreau Marc , Leclerc Catherine , Néant Isabelle
Published: November 2020

La formation du système nerveux débute par l’induction neurale, un processus qui permet aux cellules de l’ectoderme (tissu cible) d’acquérir un destin neural en réponse à des signaux provenant du mésoderme dorsal (tissu inducteur). Ce processus, décrit en 1924 sur l’amphibien, n’a reçu une explication moléculaire qu’au milieu des années 1990. Pendant cette période, plusieurs auteurs se sont intéressés au rôle joué par la membrane du tissu cible mais peu de travaux décisifs ont décrit la transduction du signal neuralisant. Entre 1990 et 2019, nous avons disséqué la transduction du signal neuralisant, un sujet très peu abordé alors. Nous avons souligné le rôle nécessaire et suffisant du calcium pour orienter les cellules de l’ectoderme vers un destin neural et établi la cascade moléculaire allant de l’activation de canaux membranaires à la transcription de gènes.
Auswirkungen des Lockdowns auf Betätigung – Occupational Transition in der Pandemie
Authors: Lang Rebecca
Published: November 2020

Für viele war der Lockdown in der Corona-Pandemie herausfordernd. Aus Sicht der Occupational Science verdeutlicht die Zeit, welch zentrale Rolle menschliches Handeln in lebensverändernden Situationen einnimmt, wie sich Betätigungsverluste auf das Wohlbefinden auswirken und was zur Anpassung beitragen kann.
Higher Institutional Volume Reduces Mortality in Reoperative Proximal Thoracic Aortic Surgery
Authors: Shea Nicholas J. , D'Angelo Alex M. , Polanco Antonio R. , Allen Philip , Sanchez Joseph E. , Kurlansky Paul , Patel Virendra I. , Takayama Hiroo
Published: November 2020

Objective This study aims to determine the impact of institutional volume on mortality in reoperative proximal thoracic aortic surgery patients using national outcomes data.

Methods The Nationwide Inpatient Sample was queried from 1998 to 2011 for patients with diagnoses of thoracic aneurysm and/or dissection who underwent open mediastinal repair. A total of 103,860 patients were identified. A total of 1,430 patients had prior cardiac surgery. Patients were further stratified into groups by institutional aortic volume: low (<12 cases/year), medium (12–39 cases/year), and high (40+ cases/year) volume. Multivariable risk-adjusted analysis accounting for emergent status and aortic dissection among other factors was performed to determine the impact of institutional volume on mortality.

Results Overall mortality was 12% in the reoperative population. When the redo cohort was divided into tertiles, high-volume group had a 5% operative mortality compared with 9 and 15% for the medium- and low-volume groups, respectively. Multivariable analysis revealed that patients operated on at low- (odds ratio [OR] = 5.0, 95% confidence interval [CI]: 2.6–9.6, p < 0.001) and medium-volume centers (OR = 2.1, 95% CI: 1.1–4.2, p = 0.03) had higher odds of mortality when compared with patients operated on at high-volume centers.

Conclusions High-volume aortic centers can significantly reduce mortality for reoperative aortic surgery, compared with lower volume institutions.
Clinical Practice Variation and Outcomes for Stanford Type A Aortic Dissection Repair Surgery in Maryland: Report from a Statewide Quality Initiative
Authors: Mazzeffi Michael , Ghoreishi Mehrdad , Alejo Diane , Fonner Clifford E. , Tanaka Kenichi , Abernathy James H. , Whitman Glenn , Salenger Rawn , Lawton Jennifer , Ad Niv , Brown James , Gammie James , Taylor Bradley ,   On behalf of the Investigators for the Maryland Cardiac Surgery Quality Initiative
Published: November 2020

Background Stanford Type A aortic dissection repair surgery is associated with high mortality and clinical practice remains variable among hospitals. Few studies have examined statewide practice variation.

Methods Patients who had Stanford Type A aortic dissection repair surgery in Maryland between July 1, 2014 and June 30, 2018 were identified using the Maryland Cardiac Surgery Quality Initiative (MCSQI) database. Patient demographics, comorbidities, surgery details, and outcomes were compared between hospitals. We also explored the impact of arterial cannulation site and brain protection technique on outcome.

Results A total of 233 patients were included from eight hospitals during the study period. Seventy-six percent of surgeries were done in two high-volume hospitals (≥10 cases per year), while the remaining 24% were done in low-volume hospitals. Operative mortality was 12.0% and varied between 0 and 25.0% depending on the hospital. Variables that differed significantly between hospitals included patient age, the percentage of patients in shock, left ventricular ejection fraction, creatinine level, arterial cannulation site, brain protection technique, tobacco use, and intraoperative blood transfusion. The percentage of patients who underwent aortic valve repair or replacement procedures differed significantly between hospitals (p < 0.001), although the prevalence of moderate-to-severe aortic insufficiency was not significantly different (p = 0.14). There were no significant differences in clinical outcomes including mortality, renal failure, stroke, or gastrointestinal complications between hospitals or based on arterial cannulation site (all p > 0.05). Patients who had aortic cross-clamping or endovascualr repair had more embolic strokes when compared with patients who had hypothermic circulatory arrest (p = 0.03).

Conclusion There remains considerable practice variation in Stanford Type A aortic dissection repair surgery within Maryland including some modifiable factors such as intraoperative blood transfusion, arterial cannulation site, and brain protection technique. Continued efforts are needed within MCSQI and nationally to evaluate and employ the best practices for patients having acute aortic dissection repair surgery.
Electroencephalographic Findings in Pediatric Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis: The San Diego Experience
Authors: Frederick Aliya , Yang Jennifer H. , Guido-Estrada Natalie , Soria-Lopez Jose , Sattar Shifteh
Published: November 2020

Diagnosing anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis clinically can be challenging. There is a growing interest in identifying specific electroencephalographic features to help guide early management. A retrospective chart review was conducted of pediatric patients admitted to Rady Children's Hospital between January 1, 2010 and April 1, 2017. We included patients with the diagnosis of encephalitis who underwent continuous video electroencephalogram (VEEG) for at least 12 hours, and presented with less than 14 days of symptoms. We compared the electroencephalographic features of non-rapid eye movement (NREM) sleep between patients with antibody confirmed anti-NMDAR encephalitis and patients with encephalitis from other etiologies. We identified seven patients who met our inclusion criteria, five of whom were diagnosed with anti-NMDAR encephalitis. Four of the five patients had a significant reduction in NREM sleep, while one patient had increased NREM sleep associated with clinical catatonia and hypersomnolence. Sleep was preserved in the two cases of nonimmune mediated encephalitis. Our results suggest that a prolonged VEEG to capture sleep coupled with clinical features can aid in early diagnosis and treatment of anti-NMDAR encephalitis, often before confirmatory antibody testing is available.
Ein Arzt sollte kein Strohmann sein
Authors: Weimer Tobias
Published: November 2020

Der Bundesgerichtshof hat jüngst entschieden, dass die Gründung eines MVZ über einen gründungsberechtigten vertragsärztlichen Strohmann eine Straftat darstellt. Im besagten Fall hatte ein Apotheker einen Vertragsarzt eingesetzt, um sich gewinnbringend Einfluss auf die Zytostatika-Verordnung in einem MVZ zu erschließen.
Digitalisierung in der Praxis Bei Asklepios: „Digitalisierung verlangt Ausdauer“
Authors: Doelfs Guntram
Published: November 2020

Der private Klinikkonzern Asklepios treibt seit vier Jahren die Digitalisierung der Klinikkette voran. Im Gespräch mit kma schildert CIO Henning Schneider, warum Digitalisierung ein zentrales Vorstandsthema sein muss, Technik eine nachgeordnete Rolle spielt – und clevere Blaupausen das Tempo der Digitalisierung enorm beschleunigen.
Medizintechnikbranche: Umsätze brechen wegen Corona ein
Authors: Doelfs Guntram
Published: November 2020

Die Corona-Pandemie bereitet der Medizintechnikbranche erhebliche wirtschaftliche Probleme. Während einzelne Hersteller wie Drägerwerk ein enormes Umsatzwachstum von bis zu 30 Prozent verzeichnen, rechnet die Gesamtbranche laut Bundesverband Medizintechnologie (BVMed) für dieses Jahr mit einem durchschnittlichen Umsatzrückgang von 4,9 Prozent.
Mobilfunk: 5G als Enabler im Gesundheitswesen
Authors: Hamm Steffen
Published: November 2020

Die Netzbetreiber haben mit dem Roll-out von 5G begonnen. Der neue Mobilfunkstandard unterscheidet sich technologisch gravierend von seinen Vorgängern und schafft dadurch die Voraussetzungen für eine Vielzahl neuartiger Anwendungen. Das Gesundheitswesen kann in besonderer Weise davon profitieren.
Regular random attractors for non-autonomous stochastic evolution equations with time-varying delays on thin domains
Authors: Li Dingshi , Shi Lin , Zhao Junyilang
Published: November 2020

This paper deals with the limiting dynamical behavior of non-autonomous stochastic reaction–diffusion equations with time-varying delays on thin domains. First, we prove the existence and uniqueness of the regular random attractor. Then, we prove the upper semicontinuity of the regular random attractors for the equations on a family of (n + 1)-dimensional thin domains that collapses onto an n-dimensional domain.
Collisionless Rayleigh–Taylor-like instability of the boundary between a hot pair plasma and an electron–proton plasma: The undular mode
Authors: Dieckmann M. E. , Falk M. , Folini D. , Walder R. , Steneteg P. , Hotz I. , Ynnerman A.
Published: November 2020

We study with a two-dimensional particle-in-cell simulation the stability of a discontinuity or piston, which separates an electron–positron cloud from a cooler electron–proton plasma. Such a piston might be present in the relativistic jets of accreting black holes separating the jet material from the surrounding ambient plasma and when pair clouds form during an x-ray flare and expand into the plasma of the accretion disk corona. We inject a pair plasma at a simulation boundary with a mildly relativistic temperature and mean speed. It flows across a spatially uniform electron–proton plasma, which is permeated by a background magnetic field. The magnetic field is aligned with one simulation direction and oriented orthogonally to the mean velocity vector of the pair cloud. The expanding pair cloud expels the magnetic field and piles it up at its front. It is amplified to a value large enough to trap ambient electrons. The current of the trapped electrons, which is carried with the expanding cloud front, drives an electric field that accelerates protons. A solitary wave grows and changes into a piston after it saturated. Our simulations show that this piston undergoes a collisionless instability similar to a Rayleigh–Taylor instability. The undular mode grows and we observe fingers in the proton density distribution. The effect of the instability is to deform the piston but it cannot destroy it.
Basis set extrapolation in pair natural orbital theories
Authors: Sorathia Kesha , Tew David P.
Published: November 2020

We present the results of a benchmark study of the effect of Pair Natural Orbital (PNO) truncation errors on the performance of basis set extrapolation. We find that reliable conclusions from the application of Helgaker’s extrapolation method are only obtained when using tight PNO thresholds of at least 10−7. The use of looser thresholds introduces a significant risk of observing a false basis set convergence and underestimating the residual basis set errors. We propose an alternative extrapolation approach based on the PNO truncation level that only requires a single basis set and show that it is a viable alternative to hierarchical basis set extrapolation methods.
Deficiencies in compression and yield in x-ray-driven implosions
Authors: Thomas C. A. , Campbell E. M. , Baker K. L. , Casey D. T. , Hohenberger M. , Kritcher A. L. , Spears B. K. , Khan S. F. , Nora R. , Woods D. T. , Milovich J. L. , Berger R. L. , Strozzi D. , Ho D. D. , Clark D. , Bachmann B. , Benedetti L. R. , Bionta R. , Celliers P. M. , Fittinghoff D. N. , Grim G. , Hatarik R. , Izumi N. , Kyrala G. , Ma T. , Millot M. , Nagel S. R. , Patel P. K. , Yeamans C. , Nikroo A. , Tabak M. , Gatu Johnson M. , Volegov P. L. , Finnegan S. M.
Published: November 2020

This paper analyzes x-ray-driven implosions that are designed to be less sensitive to 2D and 3D effects in Hohlraum and capsule physics. Key performance metrics including the burn-averaged ion temperature, hot-spot areal density, and fusion yield are found to agree with simulations where the design adiabat (internal pressure) is multiplied by a factor of 1.4. These results motivate the development of a simple model for interpreting experimental data, which is then used to quantify how improvements in compression could help achieve ignition.
Magnetization dynamics of nanoscale magnetic materials: A perspective
Authors: Barman Anjan , Mondal Sucheta , Sahoo Sourav , De Anulekha
Published: November 2020

Nanomagnets form the building blocks for a gamut of miniaturized energy-efficient devices including data storage, memory, wave-based computing, sensors, and biomedical devices. They also offer a span of exotic phenomena and stern challenges. The rapid advancements of nanofabrication, characterization, and numerical simulations during the last two decades have made it possible to explore a plethora of science and technology applications related to nanomagnet dynamics. The progress in the magnetization dynamics of single nanomagnets and one- and two-dimensional arrays of nanostructures in the form of nanowires, nanodots, antidots, nanoparticles, binary and bi-component structures, and patterned multilayers have been presented in detail. Progress in unconventional and new structures like artificial spin ice and three-dimensional nanomagnets and spin textures like domain walls, vortex, and skyrmions has been presented. Furthermore, a huge variety of new topics in the magnetization dynamics of magnetic nanostructures are rapidly emerging. A future perspective on the steadily evolving topics like spatiotemporal imaging of fast dynamics of nanostructures, dynamics of spin textures, and artificial spin ice have been discussed. In addition, dynamics of contemporary and newly transpired magnetic architectures such as nanomagnet arrays with complex basis and symmetry, magnonic quasicrystals, fractals, defect structures, and novel three-dimensional structures have been introduced. Effects of various spin–orbit coupling and ensuing spin textures as well as quantum hybrid systems comprising of magnon–photon, magnon–phonon, and magnon–magnon coupling and antiferromagnetic nanostructures have been included. Finally, associated topics like nutation dynamics and nanomagnet antenna are briefly discussed. Despite showing great progress, only a small fraction of nanomagnetism and its ancillary topics have been explored so far and huge efforts are envisaged in this evergrowing research area in the generations to come.
Cathodoluminescence spatially resolves optical transitions in thick group-III and N-polar InGaN films
Authors: Bansal Anushka , Redwing Joan M. , Al Balushi Zakaria Y.
Published: November 2020

The growth of thick group-III polar InGaN films beyond the critical thickness remains a challenge due to the large miscibility gap and lattice mismatch between InN and GaN leading to phase separation and inhomogeneous distribution of indium that impacts the luminescence properties across the film. The growth of N-polar InGaN can circumvent these challenges due to the increased stability of InN, thus improving film quality. However, overall luminescence from N-polar InGaN films is consistently lower than that of group-III polar InGaN films grown under identical conditions. In this study, spatially resolved cathodoluminescence (CL) measurements are used to reveal the optical properties of group-III and N-polar thick InGaN films. In the case of group-III polar films, predominant CL luminescence arises from the periphery of V-pits which are regions with a high accumulation of indium, while negligible CL luminescence is observed at the apex of the V-pit, indicative of centers for non-radiative recombination. Large differences in the CL luminescence intensity between the group-III polar and N-polar InGaN are a result of significant differences in the carrier lifetimes of the respective polarities (∼50–200 ps: N-polar, ∼500–700 ps: group-III polar InGaN). Since the decay behavior of the transient in N-polar InGaN is bi-exponential, it is suspected that oxygen impurities play a dominant role in the overall luminescence quenching in N-polar InGaN films.