bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of impact cam mechanisms from the point of view of the rationality of their use in drilling machines
Authors: Teplyakova Anna , Zhukov Ivan
Published: November 2021

Modern drilling machines designed for the destruction of rocks have a diverse structure, various performance characteristics and in most cases a well-defined limited scope of application. One of the variants of the design of such machines is the integration of impact cam mechanisms into their structure, the variety of which allows achieving the specified working conditions. The most suitable one for impact machines is the front cam mechanism, in which the rotational movement of the cam is converted into the translational movement of the driven link – the pusher. Only cam mechanisms allow implementing a certain law of motion of the output-working link accurately. This article provides an overview of the well-known patented impact machines equipped with impact cam mechanisms. A brief description of each technical solution is provided, indicating mechanism differences and uniqueness. Based on the results of the critical analysis of the found machines and mechanisms, the tasks of further research are formulated. These results will be the development of scientific knowledge in the field of the use of cam mechanisms in impact machines, namely in drilling machines that can automatically adapt to operating conditions.
Development of the conceptual design of vehicles for off-road container transportation for mining applications
Authors: Evseev Kirill , Kositsyn Boris , Kotiev George , Stadukhin Anton , Smirnov Igor
Published: November 2021

The article substantiates the relevance of off-road container transportation by ground railless transport vehicles and weight-size parameters of the transported cargo for the mining operations. A hierarchy of complex mobility properties is developed to investigate the significance of performance properties, which is divided into levels of properties. Taking into account the hierarchy of properties, the measuring instruments are determined, the indicators of which can be used to determine the priority technical solution for container and rock transportation vehicles. The article provides a classification of tracked vehicles and tracked trains with the analysis of their design and layout variants. As a result, variants of the concepts of vehicles for off-road container and rock transportation have been formed. Based on the analysis of the hierarchy of performance properties, design and layout variants of modern tracked vehicles and considering the selected objects of research, the conceptual design of a semi-trailer tracked train and a tracked train with a double-hinge fifth wheel coupling has been proposed.
Solution of the problem of recultivation of sludge sites at the oil fields by electroosmosis
Authors: Porsev Evgeny , Malozyomov Boris , Rozhkova Marina
Published: November 2021

The problem of reclamation of sludge pits in oil fields is still being solved using the resource-intensive method. An accelerated technology of sludge dewatering by electroosmotic action is proposed. The concept of specific energy consumption for mass transfer is introduced. To eliminate the influence of relaxation of gradient fields, it is proposed to change the parameters of electrical energy. A graphic-analytical method for selecting the power of an energy source is proposed. The article shows that electroosmosis can be the optimal physical process for dewatering drill cuttings. To reduce the time of the process of reclamation of sludge pits, it is advisable to eliminate the relaxation of various force gradient fields by changing the parameters of the electricity supplied to the electrodes. Recommendations are given that the technological cycle of reclamation should be carried out in one summer season, during which, using electroosmosis, reduce the moisture content of the sludge and the concentration of chemical pollutants to an acceptable level, and then sow the barn with plants and thereby return the area to normal use.
Analysis of transport system stability
Authors: Borodulina Svetlana , Tabachnikova Ekaterina
Published: November 2021

The article considers the description of the internal sustainability of regional road transport systems through parameters that reflect potential and realised opportunities in regional freight transport operations. There is the author’s vision of the regional road transport system for the transport of goods by road as a target-oriented set of elements, including vehicles, transport infrastructure, technical devices, equipment, and employees, organisational structures that ensure the achievement of management objectives in the transport sector of the region. They conclude that an important element in the management of the functioning and developing road transport in the region is considering the factors that determine the internal sustainability of the system. The paper provides the author’s definition of the internal sustainability potential of the regional road transport system. It proposes an approach to assess the internal sustainability of regional road transport systems based on the elements of regional transport system capacity, such as infrastructure capacity, operational capacity and freight demand capacity in the region. Researchers developed a system of indicators to assess each capacity element from the perspective of the internal sustainability of the system. The article focuses on the study of system stability based on the assessment of deviations from equilibrium states that ensure the stability of the system within its baseline parameters and characteristics, and its adaptability to deviations from the baseline values. It uses regional statistics to assess the internal sustainability of regional road transport systems and describes their internal instability factors. The authors present a visualisation of a model for assessing the internal sustainability of a regional transport system.
Technological assurance of the quality of processing of products from aluminum alloys with a complex geometric shape using magnetic abrasive processing
Authors: Maksimov Dmitriy , Shcheglova Radmila , Klochkov Dmitriy
Published: November 2021

In the presented article, the issue of the implementation of magnetic abrasive processing is considered in order to ensure the quality of surfaces of complex shapes of parts made of corrosion-resistant aluminum alloys. The implementation was carried out through theoretical and experimental research. In a theoretical study, the features of processing corrosion-resistant aluminum alloys, existing and possible schemes for magnetic-abrasive processing of surfaces of complex geometric shapes, including a combination of various working movements of the workpiece and pole pieces, are considered. In an experimental study, the dependence of the quality of the processed surface (roughness) on the size of the working gap between the workpiece and the working pole was determined. The result of the research is the determination of the optimal treatment schemes for surfaces with a complex geometric shape, as well as the derived exponential dependence of the change in surface roughness on the size of the working gap.
Study of loose bulk cargo storage conditions and water transportation
Authors: Novikova Tatyana , Stikhova Alla , Zhmyrko Tatyana
Published: November 2021

When transporting such cargos as mineral fertilizers by water, they absorb moisture, which stimulates cargo self-heating and ultimately leads to dangerous temperature limits. When transporting ANP fertilizer in holds, its equilibrium moisture content can change significantly, which can lead to the cargo damage. The article presents the findings on the processes of hydrothermal moistening of porous bodies on the example of ANP fertilizer associated with the phenomena of sorption and desorption. There is no analytical description of moistening processes of porous bodies associated with these phenomena in the scientific literature. The optimal conditions for storage and transportation of bulk materials have been determined on the example of ANP fertilizer transported through the Novorossiysk seaport. As a result of the study, the moisture content intervals associated with various types of absorption were established. Thus, in the range of ⱷ from 0% to 16% moisture content, monomolecular adsorption prevails, which corresponds to the normal moisture content of ANP fertilizer. In the range of ⱷ from 16% to 54%, polymolecular adsorption predominates, and at the value of ⱷ greater than 87%, a smooth transition from predominantly polymolecular adsorption to capillary condensation occurs, which will negatively affect the process of humidification and cargo caking.
Reducing the maximum power consumption of a group of sucker-rod pumps with the mechatronic drive by optimizing the control algorithm
Authors: Larin Mikhail , Volkov Andrey
Published: November 2021

For the development of lowand medium-rate wells, the most commonly used installations are sucker-rod pumps. The group of sucker-rod pumps connected to the same power supply system is installed on the wells of one oilfield. The work of a sucker-rod pump is cyclical. Obviously, there is a relationship between the maximum power consumption of a group of cycle drives and the performance of this group. Selecting such a strategy for reducing the maximum power consumption, in which there will be no significant performance reduction, is an urgent problem. In this article, theoretical approaches are formulated for constructing the simulation model of a sucker-rod pump group as a group of cycle drives with unequal cycles. Several group control strategies that reduce the maximum value of power consumption are considered.
Simultaneous optimization scheduling with two agents on an unbounded serial-batching machine
Authors: He Cheng , Li Shi-Sheng , Wu Jing
Published: November 2021

This paper considers a class of simultaneous optimization scheduling with two competitive agents on an unbounded serial-batching machine. The cost function of each agent depends on the completion times of its jobs only. According to whether the jobs from different agents can be processed in a common batch, compatible model and incompatible model are investigated. For the incompatible model, we consider batch availability and item availability. For each problem, we provide a polynomial-time algorithm that can find all Pareto optimal schedules.
Ensuring the Competitiveness of the Ukrainian Woodworking Industry in the Post-Pandemic Period
Authors: Hubarieva Irina , Hubariev Oleksandr , Zinchenko Volodymyr , Pronoza Pavlo
Published: November 2021

The woodworking industry is one of the most critical components of the forest sector in Ukraine and world countries. This paper aims to develop directions for ensuring the competitiveness of the woodworking industry in the post-pandemic period. The study resulted in the elaboration of the theoretical framework for identifying the main substantive determinants of industrial competitiveness in world countries through bibliometric analysis using VOSviewer v.1.6.10. The conducted cluster analysis provided for the identification of 4 clusters of scientific research dealing with issues of industrial competitiveness (Cluster 1 is focused on the formation of a competitive business strategy for the development of industrial enterprises; Cluster 2 – on the development of the export-import potential of industrial enterprises; Cluster 3 – on the identification of relationships between ensuring industrial competitiveness and globalisation processes; Cluster 4 – on the implementation of Industry 4.0 and innovative technologies). The obtained theoretical conclusions and generalisations became the basis for forming a system of indicators for assessing the competitiveness of economic activities in the country's woodworking industry. An integrated assessment of the competitiveness of the woodworking industry in Ukraine and world countries was carried out. Using cluster analysis (k-means), world countries, including Ukraine, were clustered according to the value of composite indicators for assessing the competitiveness of individual economic activities in the woodworking industry. Ukraine fell into the cluster characterised by the high competitiveness of individual economic activities in the woodworking industry. Measures were formulated to ensure the competitiveness of the Ukrainian woodworking industry in the post-pandemic period.
Smart Specialisation Strategy in the Post-Pandemic Times: the Evidence of Belarus
Authors: Pranuza Yuliya
Published: November 2021

Innovation is recognised as one of the means of implementation for the entire 2030 Agenda for Sustainable Development. The Covid19 pandemic has resulted in slowed economic development. The innovation will have to play an essential role in recovering from the aftermath of the coronavirus. This article discusses how the application of the Smart Specialisation Strategy (S3) will allow faster recovery from the Covid-19 pandemic. The results of the study indicate that (1) S3 are place-based, innovation-led transformation policy for growth and sustainability; (2) the application of S3 allows to choose the priorities within the framework of innovative development; (3) Smart Specialisation can be an effective tool to help regions recover from the pandemic crisis and find new opportunities for more sustainable economies; (4) European Union (EU) countries have successful experience of the application S3; (5) the approach of Smart Specialisation can be applicable in Belarus for creating a competitive advantage for regions; (6) the areas of national and regional importance for the economy of Belarus were identified that could form the basis of the application of the Smart Specialisation approach in Belarus.
Problem-oriented Management of United Territorial Communities’ Development Based on Decentralization under the Pandemic Influence
Authors: Ivanov Yuriy , Ivanova Olga , Laptiev Viacheslav , Polyakova Olga , Shlykova Viktoriia
Published: November 2021

The article is devoted to the problem-oriented management of spatial development of united territorial communities (UTC) under the conditions of decentralization under the influence of economic consequences of the Covid-19 pandemic. The article aims to justify the problem-oriented approach in the management of UTC based on the development of a cognitive map of the problems of their development and modelling the problem-oriented management of community resources on the example of human resources. The problem-oriented approach to resource management focuses on solving a problem as a specific theoretical or practical problem, which in turn adaptability, flexibility, the ability to make timely management decisions using available resources. The cognitive map of the four groups of problems of UTC development was developed: problems of the spatial development of UTC and administrative-territorial structure; problems of socio-economic development based on self-sufficiency; problems of local self-government system; problems of rural territories development. The example of human resources scenarios of problem-oriented management of community resources at the macro-, meso-; micro-levels were offered. The hypothesis that the effect of measures “from below” will spread more rapidly than “from above” has been proved.
Democracy Backsliding as a Danger of Sustainable Development in the Post-Pandemic Period: Social and Legal aspects of Decision
Authors: Tkach Oleg , Batrymenko Оleh , Nelipa Dmytro , Khylko Mykola
Published: November 2021

The article considers topical issues of the threat of collapse of democracy. Examples of the democracy collapse have shown the lack of free and fair elections in the world, which threatens the independence of the judiciary, restrictions on the right to freedom of speech, which limits the ability of the political opposition to challenge the government, to prosecute, to offer alternatives to the regime. The collapse of democracy in connection with the spread of COVID-19 is being considered, as the democratic spectrum has repeatedly resorted to excessive control, discriminatory restrictions on freedoms such as movement and assembly, and arbitrary or coercive coercion. Attention is drawn to the fact that the outbreak of coronavirus COVID-19 has led to the introduction in all countries of restrictions on the rights and freedoms of the individual in order to prevent the spread of this infectious disease, declared a global pandemic by the World Health Organization. Thus, the unusual nature of the COVID - 19 coronavirus pandemic poses numerous dilemmas to the public, governments, parliaments, the judiciary, law enforcement and many other actors when it comes to the need for effective protection of health and, ultimately, human life, as well as adherence to and ensuring the fundamental democratic principles of man and society.
The Strategy Focuses of Recreation and Tourism Activities of Ichnia National Nature Park (Ukraine) Design Employing Canvas Business-model and SWOT-analysis
Authors: Kiptenko Viktoriia , Mykhailenko Tetiana
Published: November 2021

National parks across the world contribute to the preservation of biodiversity, playing simultaneously an outstanding role in sustainable activities, recreation and tourism in particular. Experience with COVID-19 shows that resilience is fundamental to the sustainability of protected area visitation, which was affected in different ways by pandemics. The last decade challenges for the national nature parks of Ukraine, positive impetuses of several successful projects, enhancement of the community role in the environmental issues caused the search for a framing of the strategy of recreation and tourism activity of the national nature park located in Ichnia, Chernihiv oblast, Ukraine. By employing the Canvas business model and SWOT analysis the client-oriented shift in the above park strategy focuses ground prospects for facts-based decision-making and planning. The focuses advised include restructuring of the organizational patterns of the entity; modernisation of information and communication activities; profiling of demand and diversification of values for travellers of different motivation; networking with stakeholders.
Customer Engagement with Universities’ Social Media after COVID-19: EaP Countries Case
Authors: Chala Nina , Pichyk Kateryna , Voropai Olga , Bilovodska Olena
Published: November 2021

The current research aims at analyzing the social media activity of the universities in EaP countries. During the COVID-19 pandemic, universities had to transfer their education processes and enrollment campaigns online. University management had to introduce new tools for communication and interaction to ensure the efficacy of cooperation between the university community, students, teaching staff, and other stakeholders. In this research, the authors analyze which factors affected the dynamics and directions of customer engagement with Universities' social media and how. The authors propose a framework to reveal the role of countries’ digital environment, educational environment, and university’s SM activity in increasing ER of university stakeholders during the COVID-19 pandemic on Facebook and Instagram. The authors outline managerial proposals for universities, including analytics-based SM content creation and planning, communicating socially essential issues.
Financial Flexibility of Universities in Adaptation to Covid-19 Challenges
Authors: Yurchyshena Liudmyla , Laktionova Olexandra
Published: November 2021

During the adaptation of universities to Covid-19, the problem of their financial flexibility has become crucial. The ability to react quickly during a pandemic crisis with changes of training format and educational activities, the flexibility to respond to external challenges under the scarce resources, maintenance of a competitive position on the market of educational services are the symptoms and implications of financial flexibility. The purpose of the article is to determine the signs of the university’s financial flexibility, which could be the basis for designing and practical application of methodological tools for evaluating the financial flexibility of universities. The concept of financial flexibility of universities is proposed as the ability of university management to generate income, restrain and optimally allocate costs, generate cash flows with constrained budget funding during the crisis, create and implement business models, implement unique valuable educational proposals. Manifestations of financial flexibility concerning state and private financing have been defined. The signs of financial flexibility, such as sensitivity, efficiency, manoeuvrability, alternativeness, economy, have been outlined. Methodical tools and indicators for the evaluation of financial flexibility have been proposed. The degree of the impact of main factors on the financial flexibility of universities is determined.
Carotid Artery Stenosis and Ischemic Strokes in Patients with Giant Cell Arteritis
Authors: Oerding Clemens , Uhlmann Frank , Wollmann Johannes , Kaden Ingmar , Wohlfarth Kai
Published: November 2021

Purpose Ischemic stroke is a relatively rare complication of giant cell arteritis often accompanied by vessel stenosis. Our purpose was to compare the location of internal carotid artery stenosis in GCA patients by performing a literature review suggesting a specific and characteristic pattern.

Methods We performed a PubMed research including all articles and cited articles reporting cases and case series about giant cell arteritis patients with internal carotid artery stenosis and ischemic strokes.

Results In this case series 39 cases were included. We found a clear tendency of giant cell arteritis-related stenosis to be in the intracranial segments (35/39 (89.7%)). Only in 8/39 (20.5%) patients there was further involvement of extracranial segments. Many cases (27/39 [69.2%]) showed a bilateral involvement.

Discussion This literature review reveals a specific pattern of internal carotid artery involvement in patients with giant cell arteritis and ischemic strokes. To our knowledge this pattern has not been reported as a sign strongly pointing toward giant cell arteritis before. We have not found case reports mentioning other common types of vasculitis reporting this involvement pattern.

Conclusion Internal carotid artery stenosis and ischemic stroke is a rare complication in patients with giant cell arteritis. Considering the characteristic features of bilateral distal internal carotid artery stenosis giant cell arteritis should be suspected which potentially leads to an early diagnosis and immunotherapy.
Stem Cell–Based Therapies: What Interventional Radiologists Need to Know
Authors: Yu Hyeon , Commander Clayton W. , Stavas Joseph M.
Published: November 2021

As the basic units of biological organization, stem cells and their progenitors are essential for developing and regenerating organs and tissue systems using their unique self-renewal capability and differentiation potential into multiple cell lineages. Stem cells are consistently present throughout the entire human development, from the zygote to adulthood. Over the past decades, significant efforts have been made in biology, genetics, and biotechnology to develop stem cell–based therapies using embryonic and adult autologous or allogeneic stem cells for diseases without therapies or difficult to treat. Stem cell–based therapies require optimum administration of stem cells into damaged organs to promote structural regeneration and improve function. Maximum clinical efficacy is highly dependent on the successful delivery of stem cells to the target tissue. Direct image-guided locoregional injections into target tissues offer an option to increase therapeutic outcomes. Interventional radiologists have the opportunity to perform a key role in delivering stem cells more efficiently using minimally invasive techniques. This review discusses the types and sources of stem cells and the current clinical applications of stem cell–based therapies. In addition, the regulatory considerations, logistics, and potential roles of interventional Radiology are also discussed with the review of the literature.
Einkaufsgesellschaften in Deutschland: Newcomer – Bund und Bundesländer als neue Einkaufsgemeinschaften
Authors: Weyand Rudolf
Published: November 2021

Was Sie als Krankenhausleiter und Einkäufer wissen sollten.
Investigations on the P2 drive asymmetry and its effect on the shell asymmetry in a symmetry tuning experiment at the 100 kJ laser facility
Authors: Li Chuanying , Ge Fengjun , Wu Changshu , Gu Jianfa , Chen Zhongjing , Dai Zhensheng , Li Xin , Huang Tianxuan , Chen Bolun , Deng Bo , Deng Keli , Zheng Wudi , Zou Shiyang
Published: November 2021

Understanding and controlling time-dependent implosion asymmetry are essential requirements to achieve ignition. In a recent symmetry tuning experiment at the 100 kJ laser facility, an effective time-dependent symmetry control was demonstrated by modifying the ratio of the inner beam power to the outer beam power. The hohlraum radiation and the P2 drive asymmetry of a shot used to measure backlit shell asymmetry have been analyzed, and the sensitivity of the P2 shell asymmetry to the drive asymmetry has been illustrated by using the two-dimensional code LARED. The variation in the shell P2 distortion, resulting from the variation in the P2 drive asymmetry due to the three-dimensional perturbing effects introduced to the hohlraum by the diagnostic windows (DWs) and the eight removed beams, has been assessed quantitatively using a three-dimensional postprocessor. It is found that the DWs and the four removed inner beams do not vary the P2 drive asymmetry, while the four removed outer beams cause a ∼−1% variation in the P2 drive asymmetry, resulting in a more prolate implosion.
New insights of QTAIM and stress tensor to finding non-competitive/competitive torquoselectivity of cyclobutene
Authors: Momen Roya , Azizi Alireza , Morales-Bayuelo Alejandro , Pazhoohesh Mehdi , Ji Xiaobo
Published: November 2021

This study aims to investigate the phenomenon of torquoselectivity through three thermal cyclobutene ring-opening reactions (N1–N3). This research focuses on the nature of the chemical bond, electronic reorganization, predicting non-competitive or competitive reactions, and torquoselectivity preference within Quantum Theory of Atoms in Molecules (QTAIM) and stress tensor frameworks. Various theoretical analyses for these reactions, such as metallicity ξ(rb), ellipticity ε, total local energy density H(rb), stress tensor polarizability ℙσ, stress tensor eigenvalue λ3σ, and bond-path length, display differently for non-competitive and competitive reactions as well as for the conrotatory preferences either it is the transition state outward conrotatory (TSout) or transition state inward conrotatory (TSin) directions by presenting degeneracy or non-degeneracy in their results. The ellipticity profile provides the motion of the bond critical point locations due to the different substituents of cyclobutene. In agreement with experimental results, examinations demonstrated that N1 is a competitive reaction and N2–N3 are non-competitive reactions with TSout and TSin preference directions, respectively. The concordant results of QTAIM and stress tensor scalar and vectors with experimental results provide a better understanding of reaction mechanisms.
Atomic mass dependency of a localized phonon mode in SiGe alloys
Authors: Yee Chung Sylvia Yuk , Tomita Motohiro , Yokogawa Ryo , Ogura Atsushi , Watanabe Takanobu
Published: November 2021

Using molecular dynamics, the effect of an atomic mass difference on a localized phonon mode in SiGe alloys was investigated. Phonon dispersion relations revealed that a change in atomic mass causes the optical and acoustic modes to shift frequency. The results indicate that the local mode is sensitive to both Si and Ge atomic mass changes; reducing the Si atomic mass shifts the local mode to higher frequencies, and increasing the Ge atomic mass shifts the local mode to lower frequencies. Furthermore, the results suggest that the local mode originates from the Si–Ge bond vibration. Although the Si–Si, Si–Ge, and Ge–Ge optical mode frequencies are well approximated by the two-body harmonic oscillator model, a much heavier effective mass than that of the Si–Ge pair must be assumed to reproduce the local mode frequency. A plausible interpretation of the local mode is a collective vibration of Ge clusters embedded within the Si lattice.
Light and Life
Authors: Dakin James T.
Published: November 2021

Light has had a significant impact on life in general, and Homo sapiens in particular, since their beginnings, and even more so in modern times. Photosynthesis is key to life. Aspects of the eye and vision are described, and biological effects beyond the visible in the infrared (IR) and ultraviolet (UV) are discussed. Human pigmentation changes associated with vitamin D took place as our ancestors migrated away from the equator and toward the poles. Seasonal affective disorder (SAD) and circadian sleep disorder are both associated with light. The role of light and color in design is discussed. Important modern applications of light include electric lighting (discussed in much more detail in earlier chapters), data transmission, flat-panel displays, solar photovoltaics, digital imaging, and lasers.
Episodic memory enhancement versus impairment is determined by contextual similarity across events
Authors: Cox Wouter R. , Dobbelaar Simone , Meeter Martijn , Kindt Merel , van Ast Vanessa A.
Published: November 2021

Significance

It is not well understood why and how memories of similar events sometimes strengthen each other, but at other times compete, causing either facilitation or impairment of memory recollection. Reasoning that the environment (spatial context) in which events occur is a critical component of memory function, we show that similar memories strengthen each other’s retrievability when the events occurred in the same context, whereas memories impair each other’s recall when experiences took place across different contexts. Interestingly, these patterns may change or even reverse if contextual cues are present during recall. Our results thus suggest that episodic memory alterations are adjustable rather than permanent, and provide strategies to optimize memory retention and reduce interference in educational and legal settings.
Th17 cell master transcription factor RORC2 regulates HIV-1 gene expression and viral outgrowth
Authors: Wiche Salinas Tomas Raul , Zhang Yuwei , Sarnello Daniele , Zhyvoloup Alexander , Marchand Laurence Raymond , Fert Augustine , Planas Delphine , Lodha Manivel , Chatterjee Debashree , Karwacz Katarzyna , Oxenford Sally , Routy Jean-Pierre , Irlbeck David , Amrine-Madsen Heather , Ancuta Petronela , Fassati Ariberto
Published: November 2021

Significance

HIV-1 infects CD4 T cells, and, among these, T helper 17 (Th17) cells are known to be particularly permissive for virus replication. The infection of Th17 cells is critical for AIDS pathogenesis and viral persistence. It is, however, not clear why these cells are highly permissive to HIV-1. We found that Th17 cell permissiveness depends on the expression of the hormone receptor RORC2, which is the master transcriptional regulator of Th17 cell differentiation. We identify RORC2 as a cell-specific host-dependency factor that can be targeted by small molecules. Our results suggest that RORC2 may be a cell-specific target to mitigate the loss of Th17 cells as a consequence of their preferential HIV-1 infection.
Plant–environment microscopy tracks interactions of
Bacillus subtilis
with plant roots across the entire rhizosphere
Authors: Liu Yangminghao , Patko Daniel , Engelhardt Ilonka , George Timothy S. , Stanley-Wall Nicola R. , Ladmiral Vincent , Ameduri Bruno , Daniell Tim J. , Holden Nicola , MacDonald Michael P. , Dupuy Lionel X.
Published: November 2021

Significance

The lack of suitable approaches for studying root–microbe interactions, live and in situ, has severely limited our ability to understand the rhizosphere. In this study, we overcome this major limitation with an imaging system that combines transparent soils with cutting edge light sheet microscopy. The study revealed that the root cap is a point of first contact for microbes before establishment and reveals how the pore structure influences the patterns of interactions between the microbe and the plant. With the combined use of light sheet microscopy and transparent soils, we shed light on previously unseen interaction phenomena and accelerate the understanding of how rhizospheres are formed.
Liquid walls and interfaces in arbitrary directions stabilized by vibrations
Authors: Apffel Benjamin , Hidalgo-Caballero Samuel , Eddi Antonin , Fort Emmanuel
Published: November 2021

Significance

On Earth, the surface of a liquid is expected to be horizontal due to gravity. However, new equilibria with an arbitrary direction can be created by shaking the bath hard enough at a few tens of Hertz. The inertial forces resulting from the shaking produce an effective gravity in the direction of the forcing that can overcome gravity. The noncompressibility of the liquid limits the interface stability, but this can be alleviated in liquid layers trapped between two air interfaces. Thus, it is possible to obtain stable vertical liquid walls stabilized by horizontal “artificial gravity.” Buoyancy is also stabilized on all these interfaces. These results open the possibility to explore interfacial phenomena in simulated gravity environments.
C-ferroptosis is an iron-dependent form of regulated cell death in cyanobacteria
Authors: Aguilera Anabella , Berdun Federico , Bartoli Carlos , Steelheart Charlotte , Alegre Matías , Bayir Hülya , Tyurina Yulia Y. , Kagan Valerian E. , Salerno Graciela , Pagnussat Gabriela , Martin María Victoria
Published: November 2021

Ferroptosis is an oxidative and iron-dependent form of regulated cell death (RCD) recently described in eukaryotic organisms like animals, plants, and parasites. Here, we report that a similar process takes place in the photosynthetic prokaryote Synechocystis sp. PCC 6803 in response to heat stress. After a heat shock, Synechocystis sp. PCC 6803 cells undergo a cell death pathway that can be suppressed by the canonical ferroptosis inhibitors, CPX, vitamin E, Fer-1, liproxstatin-1, glutathione (GSH), or ascorbic acid (AsA). Moreover, as described for eukaryotic ferroptosis, this pathway is characterized by an early depletion of the antioxidants GSH and AsA, and by lipid peroxidation. These results indicate that all of the hallmarks described for eukaryotic ferroptosis are conserved in photosynthetic prokaryotes and suggest that ferroptosis might be an ancient cell death program.
Mechanical reliability of silicon microstructures
Authors: Tsuchiya Toshiyuki
Published: November 2021

In this article, an overview of the mechanical reliability of silicon microstructures for micro-electro-mechanical systems is given to clarify what we now know and what we still have to know about silicon as a high-performance mechanical material on the microscale. Focusing on the strength and fatigue properties of silicon, attempts to understand the reliability of silicon and to predict the device reliability of silicon-based microstructures are introduced. The effective parameters on the strength and the mechanism of fatigue failure are discussed with examples of measurement data to show the design guidelines for highly reliable silicon microstructures and devices.
A comparison of pad metallization in miniaturized microfabricated silicon microcantilever-based wafer probes for low contact force low skate on-wafer measurements
Authors: Daffe Khadim , Marzouk Jaouad , Boyaval Christophe , Dambrine Gilles , Hadaddi Kamel , Arscott Steve
Published: November 2021

Miniaturized, microfabricated microelectromechanical systems-based wafer probes are used here to evaluate different contact pad metallization at low tip forces (<mN) and low skate on the on-wafer pads. The target application is low force RF probes for on-wafer measurements which cause minimal damage to both probes and pads. Low force enables the use of softer, more conductive metallisation. We have studied four different thin film contact pad metals based on their thin film electrical resistivity and micro-hardness: gold, nickel, molybdenum, and chromium. The contact pads sizes were micrometre (1.9 × 1.9 µm2) and sub-micrometre (0.6 × 0.6 µm2). The contact resistance of Au–Au, Ni–Au, Mo–Au, and Cr–Au was measured as a function of tip deflection. The tip force (loading) of the contacts was evaluated from the deflection of the cantilever. It was observed that an overtravel of 300 nm resulting in a contact force of ∼400 µN was sufficient to achieve a contact resistance <1 Ω for a sub-micrometre gold contact pad. Our results are compared with an analytical model of contact resistance in loaded metal-metal contacts—a reasonable fit was found. A larger contact resistance was observed for the other metals—but their hardness may be advantageous when probing other materials. Using a combination of a rigid silicon cantilever (>1000 Nm−1) and small contact pads enabled us to show that it is the length of the pad (in contact with the surface) which determines the contact resistivity rather than the total contact pad area.
Beta-decay half-lives of the extremely neutron-rich nuclei in the closed-shell N = 50, 82, 126 groups
Authors: Uyen Nguyen Kim , Chae Kyung Yuk , Duy Nguyen Ngoc , Ly Nguyen Duy
Published: November 2021

The β
−-decay half-lives of extremely neutron-rich nuclei are important for understanding nucleosynthesis in the rapid neutron capture process (r-process). However, most of their half-lives are unknown or very uncertain, leading to the need for reliable calculations. In this study, we updated the coefficients in recent semi-empirical formulae using the newly updated mass (AME2020) and half-life (NUBASE2020) databases to improve the accuracy of the half-life prediction. In particular, we developed a new empirical model for better calculations of the β
−-decay half-lives of isotopes ranging in Z = 10–80 and N = 15–130. We examined the β
−-decay half-lives of the extremely neutron-rich isotopes at and around the neutron magic numbers of N = 50, 82, and 126 using either five different semi-empirical models or finite-range droplet model and quasi-particle random phase approximation method. The β
−-decay rates derived from the estimated half-lives were used in calculations to evaluate the impact of the half-life uncertainties of the investigated nuclei on the abundance of the r-process. The results show that the half-lives mostly range in 0.001 < T
1/2 < 100 s for the nuclei with a ratio of N/Z < 1.9; however, they differ significantly for those with the ratio of N/Z > 1.9. The half-life differences among the models were found to range from a few factors (for N/Z < 1.9 nuclei) to four orders of magnitude (for N/Z > 1.9). These discrepancies lead to a large uncertainty, which is up to four orders of magnitude, in the r-process abundance of isotopes. We also found that the multiple-reflection time-of-flight technique is preferable for precise mass measurements because its measuring timescale applies to the half-lives of the investigated nuclei. Finally, the results of this study are useful for studies on the β-decay of unstable isotopes and astrophysical simulations.
Phenomenology of dark matter and mirror fermions from a left–right mirror model with singlet scalar
Authors: Alam I S
Published: November 2021

We investigate a left–right mirror model with SU(3)
c
× SU(2)L × SU(2)R × U(1)
Y
and a discrete

Z

2

symmetry, which introduces mirror fields that are copies of the standard model (SM) fields. The mirror fields have the opposite chirality to their SM counterpart fields. We also introduce singlet scalars as dark matter (DM). The new interaction between DM, SM fermions, and mirror fermions can account for DM abundance, charged lepton flavor violation, lepton anomalous magnetic moment, and flavor changing neutral current. We demonstrated that if we choose DM annihilation into muon as the dominant annihilation channel for leptophilic DM, both the observed DM abundance and the observed discrepancy between theory and experiment in the muon anomalous magnetic moment can be explained without contradicting the bound derived from charged lepton flavor violating processes. We briefly discuss how mirror fermions will be produced at the future linear collider, as mirror fermions can interact with neutral gauge bosons in this model. Finally, we discuss the lightest mirror neutrino decay mechanism, which will be highly abundant if stable.
Wave-packet continuum discretisation for nucleon–nucleon scattering predictions
Authors: Miller Sean B S , Ekström Andreas , Forssén Christian
Published: November 2021

In this paper we analyse the efficiency, precision, and accuracy of computing elastic nucleon–nucleon (NN) scattering amplitudes with the wave-packet continuum discretisation method (WPCD). This method provides approximate scattering solutions at multiple scattering energies simultaneously. We therefore utilise a graphics processing unit to explore the benefits of this inherent parallelism. From a theoretical perspective, the WPCD method promises a speedup compared to a standard matrix-inversion method. We use the chiral NNLOopt interaction to demonstrate that WPCD enables efficient computation of NN scattering amplitudes provided one can tolerate an averaged method error of 1–5 mb in the total cross section at scattering energies 0–350 MeV in the laboratory frame of reference. Considering only scattering energies ∼40–350 MeV, we find a smaller method error of ≲ 1–2 mb. By increasing the number of wave-packets we can further reduce the overall method error. However, the parallel leverage of the WPCD method will be offset by the increased size of the resulting discretisation mesh. In practice, a GPU-implementation is mainly advantageous for matrices that fit in the fast on-chip shared memory. We find that WPCD is a promising method for computationally efficient, statistical analyses of nuclear interactions from effective field theory, where we can utilise Bayesian inference methods to incorporate relevant uncertainties.
Particle/wall electroviscous effects at the micron scale: comparison between experiments, analytical and numerical models
Authors: Hernández Meza J Manuel , Vélez-Cordero J Rodrigo , Ramírez Saito A , Aranda-Espinoza S , Arauz-Lara José L , Yáñez Soto Bernardo
Published: November 2021

We report a experimental study of the motion of 1 μm single particles interacting with functionalized walls at low and moderate ionic strengths conditions. The 3D particle’s trajectories were obtained by analyzing the diffracted particle images (point spread function). The studied particle/wall systems include negatively charged particles interacting with bare glass, glass covered with polyelectrolytes and glass covered with a lipid monolayer. In the low salt regime (pure water) we observed a retardation effect of the short-time diffusion coefficients when the particle interacts with a negatively charged wall; this effect is more severe in the perpendicular than in the lateral component. The decrease of the diffusion as a function of the particle–wall distance h was similar regardless the origin of the negative charge at the wall. When surface charge was screened or salt was added to the medium (10 mM), the diffusivity curves recover the classical hydrodynamic behavior. Electroviscous theory based on the thin electrical double layer (EDL) approximation reproduces the experimental data except for small h. On the other hand, 2D numerical solutions of the electrokinetic equations showed good qualitative agreement with experiments. The numerical model also showed that the hydrodynamic and Maxwellian part of the electroviscous total drag tend to zero as h → 0 and how this is linked with the merging of both EDL’s at close proximity.
Unveiling electronic and magnetic properties of Cu3(SeO3)2Cl2 and Cu3(TeO3)2Br2 oxohalide systems via first-principles calculations
Authors: Lafargue-Dit-Hauret William , Rocquefelte Xavier
Published: November 2021

Here, we report a theoretical investigation of the electronic and magnetic properties of two oxohalide compounds, namely Cu3(SeO3)2Cl2 and Cu3(TeO3)2Br2, using density functional theory (DFT). These layered systems are characterized by two inequivalent Cu sites, with CuO4 and CuO4
X (X = Cl, Br) environments, respectively. A new magnetic model is proposed through the calculation of the magnetic exchange couplings. Our study discloses the participation of the Se and Te lone-pairs to the long-range magnetic order, providing potential key informations for future chemical design of original magnetic systems.
Iron-based magnetic superconductors AEuFe4As4 (A
= Rb, Cs): natural superconductor–ferromagnet hybrids
Authors: Liu Ya-Bin , Liu Yi , Cao Guang-Han
Published: November 2021

Superconductivity (SC) and ferromagnetism (FM) are normally antagonistic, and their coexistence in a single crystalline material appears to be very rare. Over a decade ago, the iron-based pnictides of doped EuFe2As2 were found to render such a coexistence, primarily because of the Fe–3d multi-orbitals which simultaneously satisfy the superconducting pairing and the ferromagnetic exchange interaction among Eu local spins. In 2016, the discovery of the iron-based superconductors AEuFe4As4 (A = Rb, Cs) provided an additional and complementary material basis for the study of the coexistence and the interplay between SC and FM. The two sibling compounds, which can be viewed as an intergrowth or a hybrid between AFe2As2 and EuFe2As2, show SC in the FeAs bilayers at T
c = 35–37 K and magnetic ordering at T
m ∼ 15 K in the sandwiched Eu2+-ion sheets. Below T
m, the Eu2+ spins align ferromagnetically within each Eu plane, making the system as a natural atomic-thick superconductor–ferromagnet superlattice. This paper reviews the main research progress in the emerging topic during the past five years. An outlook for the future research opportunities is also presented.
High-responsivity photodetector based on scrolling monolayer MoS2 hybridized with carbon quantum dots
Authors: Zhang Shichao , Gao Feng , Feng Wei , Yang Huihui , Hu Yunxia , Zhang Jia , Xiao Haiying , Li Zhonghua , Hu PingAn
Published: November 2021

The monolayer MoS2 based photodetectors have been widely investigated, which show limited photoelectric performances due to its low light absorption and uncontrollable adsorbates. In this paper, we present a MoS2-based hybrid nanoscrolls device, in which one-dimensional nanoscrollsof MoS2 is hybridized with carbon quantum dots (CQDs). This device architecture effectively enhanced the photodetection performance. The photoresponsivity and detectivity values of MoS2/CQDs-NS photodetectors are respectively 1793 A W−1 and 5.97 × 1012 Jones, which are 830-fold and 268-fold higher than those of pristine MoS2 under 300 nm illumination at V
ds = 5 V. This research indicates a significant progress in fabricating high-performance MoS2 photodetectors.
Silica covered stannic oxide nanoparticles—an easily prepared robust substrate for optical sensors
Authors: Chen Yuan , Ren Tianyu , Bramlitt Sarah , Seitz W Rudolf
Published: November 2021

This paper describes a facile way to prepare a photophysically inert sensor substrate. Stannic oxide encapsulated silica nanoparticles with average diameters between 30 and 70 nm have been prepared by one-pot reverse-phase emulsion methodology. The constituents and core/shell morphology of the nanoparticles were demonstrated by electron microscopic technology, energy-dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy. X-ray diffraction was employed to provide additional constitutional and structural information. It has been shown that nanoparticles prepared by this method are optically clear in suspension. After anchoring optical indicators, this nanoparticle can be utilized as a sensor module both in biology and other analytical areas.