bluuebunny/crossref_metadata_2025 huggingface dataset:
Features of the introduction of ornamental herbaceous plants native to the Russian Far East region in Laboratory of Ornamental Plants, at Main Botanical Garden of Russian Academy of Science
Authors: Bondorina Irina A. , Kabanov Alexander V. , Khokhlacheva Julia A.
Published: October 2021

Based on a long-term introduction study of the species native to the Russian Far East region, a representative collection was collected, including a wide range of ecological groups. On the basis of the conducted research, the peculiarities of the preservation of individual species in the collection fund (the ability to persist in culture for a long time, vegetative renewal, self-seeding) are revealed. It is noted that for a number of species, in addition to active vegetative overgrowth, mass self-seeding is also noted. Despite the prospects of such species in the introduction work, they can pose a potential threat to invasion. That is why only those species that are not characterized by regular and mass self-seeding are recommended for use in urban landscaping.
The concept of introduction and breeding of non-traditional vegetable plants in Siberia
Authors: Fotev Yury , Artemyeva Anna
Published: October 2021

The introduction of new vegetable crops in the harsh climate of Siberia presupposes the evaluation of resistance to environmental factors (long day, low temperatures, fungal diseases etc.) limiting the growth of plants, using pre-breeding methods.The studies were carried out in the outdoor and unheated plastic greenhouse conditions of the Central Siberian Botanical Garden (CSBS), Novosibirsk (54 ° N 83 ° E) and in the outdoor and the conditions of phytotron of the N.I.Vavilov All-Russian Institute of Plant Genetic Resources (VIR). We used a large collection of species accessions belonging to families Leguminosae, Cucurbitaceae and Brassicaceae. It is proposed to use the taxonomically important, stable traits and other features that affect the possibility of scaling up the cultivation of crops in Siberia. Sequential assessment, e. g. asparagus bean includes evaluation of resistance to a long day, cold resistance in the phase of mature male gametophyte in vitro, the composition of pathogenic micromycetes, and the resistance of accessions to them. Also, it is offered to use the symbiotic systems, including the effective strains of Bradyrhizobium sp. and high-yield cultivars with a neutral response to day length and low variation in biochemical composition, for example, the cultivar ‘Sibirskiy razmer’ bred in the CSBS.
The Introduction and Breeding of Vaccinioideae in Russia
Authors: Gorbunov Aleksey , Tyak Galina , Makeev Valeriy , Kurlovich Tatyana
Published: October 2021

This article briefly reviews the history of researching the introduction and breeding of cranberry, blueberry and cowberry in the world. The results and prospects of research in these areas in the CSBS SB RAS and the CEFES ARRISMF are presented. The article shows the effectiveness of selecting from natural populations promising material for introduction and breeding, and also the usage of intraspecific and interspecific hybridization for Vaccinioidaea breeding. As a result of longterm studies, the collections of Vaccinioidae were made in Russia. In CSBG SB RAS it totals 7 species, 1 subspecies, 54 varieties, 8 hybrids, 101 forms, including 64 selections and world’s first 8 varieties of Vaccinium uliginosum. In CE FES ARRISMF it totals 7 species, 1 subspecies, 82 varieties, 40 hybrids, 58 forms including 40 selections and the first Russian 7 varieties of Oxycoccus palustris and 3 varieties of Vaccinium vitis-idaea.
Biomorphological analysis and developmental features of two short-lived plants: Stachys annua (L.) L. and Clinopodium acinos (L.) Kuntze
Authors: Komarevtseva Elizaveta , Astashenkov Alexey
Published: October 2021

To clarify life form, ontogeny and features shoot formation of individuals Stachys annua and Clinopodium acinos were studied. It was found that the duration ontogeny of species is determined by rate of development shoot of an individual. It was found that both species bloom in the first year, however, individuals of S. annua, having reached their maximum growth, completely die off at the end of the first growing season. Accelerated development of S. annua individuals leads to the formation of powerful synflorescence and inhibition development unrealized buds of basal part shoot. In contrast to S. annua, ontogeny of C. acinos individuals is long (5–6 years). The slowed down development rate of the C. acinos shoot leads formation of a weak generative sphere and development of innovation zone consisting of 1–2 metameres with functionally developed naked buds. The performed biomorphological analysis allows us to classify S. annua as typical annual monocarpic, C. acinos as oligocarpic, belonging to the sensu lato short-lived plants group.
Features of the population organization of Myricaria bracteata in the riverbed of the Ursul River (Gorny Altai)
Authors: Lyakh Elena M. , Astashenkov Alexey Yu.
Published: October 2021

The article represents the analysis of the ontogenetic composition and demographic parameters of 3 cenopopulations of Myricaria bracteata in the riverbed of the Ursul River (Central Altai). It was found that the ontogenetic structure and density of individuals depend on the degree of formation of the phytocenosis and the influence of abiotic factors (features of the substrate, river bend). The invasive cenopopulation formed in a bend of the river in the absence of a phytocenotic pressure; the young normal cenopopulation formed in the river deflection on the grasscover stony shore, and the invasive-regressive cenopopulation formed on an island washed by the river.
Allelopathic activity of Acer negundo L. leaf litter as a vector of invasion species into plant communities
Authors: Nikolaeva Anastasia A. , Golosova Elena V. , Shelepova Olga V.
Published: October 2021

The article shows the results of the influence of different concentrations of allelochemicals of Acer negundo L. leaf litter, germination energy, absolute germination of seeds and plant growth. The seeds of Raphanus sativus L. and Avena sativa L. were used as model objects. Active substances contained in leaf litter A. negundo, have a selective inhibitory effect on the germination of seeds and the growth of seedlings of monocotyledonous and dicotyledonous plants. The allelopathic effect of the fall is not a limiting factor for the germination of seeds of herbaceous plants of the above-ground cover of the studied plantation.
Research improvement of the strength characteristics of rocks under volumetric compression
Authors: Pudov Eugeny , Bedarev Nikolay , Shakhmanov Vitaly , Lyubimov Oleg
Published: October 2021

The article describes some aspects of the research and applied works, which the authors carried out to expand the scope of application in the study of rock strength indicators in the laboratory of KuzSTU (Prokopyevsk branch) on a complex equipment. It consists of an extreme deformation chamber and a volumetric compression chamber. It describes the disadvantages of the volumetric compression chamber. The disadvantages have been eliminated by using a special device for fixing the sample when descending into the volumetric compression chamber. The article also gives the description of the operation of a volumetric compression chamber with the possibility of testing rock samples for a breakage under the volumetric compression. The first test results are presented.
Study of composition and properties of carbon-containing industrial rubber waste pyrolyzates
Authors: Makarevich Evgeniуa , Papin Andrey , Cherkasova Tatiana
Published: October 2021

The study of mining industry rubber waste pyrolyzates and the search for new opportunities to expand the areas of their application remains an urgent research task. The study of the solid residue of industrial rubber waste pyrolysis is presented in the work. Possibilities of improving the quality characteristics of solid carbon residue are considered. The results of studying the composition by various methods are presented. The adsorption properties of the obtained product are studied and the content of oxygen-containing functional groups in the initial and the upgraded carbon residue of pyrolysis are determined.
Unorganized sources of inorganic dust emissions. Dust suppression at mining enterprises during coal extraction, transportation, transshipment, and storage
Authors: Begunov Artem , Udovitskiy Vladimir , Kandinskiy Vladimir
Published: October 2021

Emissions of inorganic dust belong to the group of unorganized emissions that are generated from large areas. Air pollution in the area of coal industry enterprises depends on climatic and mining and geological conditions. The solution of the current mining technical problem of improving the efficiency and safety of mining operations in the development of mineral deposits, which is of great economic and social importance, is inextricably linked with the improvement of methods for fixing dusty surfaces on the objects of the mining complex. Methods of dust suppression are considered and analyzed. Industrial tests of special preventive drugs were carried out and the necessary expenditures of funds and methods of their effective use were determined.
Analysis of efficiency of drilling equipment use in mining operations
Authors: Masaev Yuriy , Masaev Vladislav , Drozdenko Yuriy
Published: October 2021

When developing coal and ore deposits by underground method, it is necessary to carry out a large volume of preparatory mine workings using drilling and blasting operations. Minerals are found in rocks under various conditions and their physical and mechanical properties change in a wide range. Under such conditions, it is necessary to use drilling machines this different to the principle of action and structural features. The article considers geometric parameters of roc cutters, peculiarities of drilling modes, affecting energy intensity and drilling productivity in rocks with different strength coefficient.
Convergence as a Structural Goal of Sustainable Economic Development: the Overview of Approaches
Authors: Zhironkin Sergey , Zhironkina Olga , Cehlar Michal
Published: October 2021

The processes of a green economy development, changes in approaches to the production and use of energy, the emergence of new sources of investment in the technological transition - all this is a consequence and, at the same time, the cause of structural shifts in the economies of advanced countries. In this light, the technological backwardness of the Russian economy, caused by a negative structural shift during the period of market reforms, impedes the transition to a green economy, rationalization of the use of natural resources and reduction of environmental pollution. Therefore, the development of theoretical provisions for the convergence of environmental and economic policies, the development of appropriate incentives for business are considered as an important step in the transition to sustainable development. For this purpose, the authors examine the original approaches to various paths of transition to sustainable development caused by structural shifts of a convergent nature in the economy.
Perioperativer Umgang mit der Dauermedikation bei kardialen Vorerkrankungen
Authors: Ninke Tobias , Kilger Erich
Published: October 2021

Arterielle Hypertonie, Herzinsuffizienz und koronare Herzerkrankung kann man in Deutschland als Volkskrankheiten betrachten. Somit ist der Anästhesist täglich mit Patienten konfrontiert, die kardial wirksame Medikamente einnehmen. Welche soll man perioperativ weiter verabreichen und welche besser pausieren? Dieser Beitrag stellt hierzu internistische Behandlungskonzepte und den perioperativen Umgang mit kardialen Medikamenten vor.
Der schwierige Atemweg mit Tracheostoma
Authors: Kösler Markus , Kabitz Hans-Joachim , Walterspacher Stephan
Published: October 2021

Falldarstellung einer 51-jährigen Patientin mit beatmungspflichtigem Charcot-Marie-Tooth-Hoffmann-Syndrom (HMSN I) sowie Spondylodese der Halswirbelsäule bei Skoliose mit komplexem Trachealkanülenmanagement. Nach anfänglicher nichtinvasiver Beatmung über 16 Jahre erfolgte bei dauerhafter Abhängigkeit von der nichtinvasiven Beatmung über 24 Stunden und progredienter respiratorischer Insuffizienz die elektive plastische Tracheotomie mit invasiver Beatmung. Aufgrund der zervikalen Spondylodese konnte mit herkömmlichen Trachealkanülen keine zufriedenstellende Versorgung erreicht werden und es erfolgte eine individuelle Anpassung einer Trachealkanüle anhand eines 3D-Druckmodells des trachealen Verlaufs mit nachfolgender hervorragender Beatmungsqualität und Sprechmöglichkeit unter invasiver Beatmung.
Organic Isocyanates and Isothiocyanates: Versatile Intermediates in Agrochemistry
Authors: Lamberth Clemens
Published: October 2021

In recent decades, organic isocyanates and isothiocyanates have been often applied as reactive intermediates in research syntheses or manufacturing routes of many agrochemicals. These heterocumulenes allowed the installation of crucial carboxylic functions, such as carbamates, ureas, and semicarbazones, but have also been used for the construction of five- and six-membered heterocycles, such as tetrazolones, thiazoles, and uracils.

1 Introduction

2 Preparation of Carboxylic Acid Functions

3 Preparation of Heterocyclic Rings

4 Conclusion
Iron-Catalyzed One-Pot Synthesis of Indole-Tethered Tetrasubstituted Pyrroles and Their Transformations to Indolizino[8,7-b]indole Derivatives
Authors: Cui Hai-Lei , Xiao Xue , Chen Xiao-Hui , Wang Xian-Xun , Li Wan-Zhen
Published: October 2021

We have developed an efficient iron-catalyzed one-pot reaction of tryptamines, ynones and nitroolefins, affording indole-tethered tetrasubstituted pyrroles in acceptable to good yields. Other aromatic and aliphatic amines can also be utilized in this process, delivering the corresponding highly functionalized tetrasubstituted pyrroles. Indolizino[8,7-b]indole derivatives could be obtained through TFA-, TfOH- or Fe(OTf)3-mediated cyclizations via dearomatization of indole. Unexpected dibrominated products, 7,9-dibromo-6,11-dihydro-5H-indolizino[8,7-b]indoles, were formed when trimethylphenylammonium tribromide (PTAP) was employed as electrophilic cyclization promoter.
Biceps, Brachialis, and Triceps
Authors: Willaume Thibault , Bierry Guillaume
Published: October 2021

Tendon injuries at the elbow affect mostly the distal biceps and can progressively degenerate over time or rupture in an acute event. The degree of retraction may depend on the integrity of the lacertus fibrosus, a fibrous expansion that merges with the forearm flexor fascia. Biceps disorders are frequently associated with fluid or synovitis of the adjacent bicipital bursa; primary bursal disorders (primary inflammatory synovitis) can also be observed. Distal triceps is less frequently injured than the distal biceps, and tears usually manifest as distal ruptures with avulsion of a small flake of bone from the tip of the olecranon. Brachialis injuries are uncommon and the consequence of sudden muscle stretching during forced elbow hyperextension, as in posterior elbow luxation.
Pediatric Imaging of the Elbow: A Pictorial Review
Authors: Vanmarsnille Tim , Laloo Frederiek , Herregods Nele , Jaremko Jacob L. , Verstraete Koenraad L. , Jans Lennart
Published: October 2021

The elbow is a complex joint, subject to a wide range of traumatic, inflammatory, metabolic and neoplastic insults. The pediatric elbow has several diagnostic pitfalls due to the normal developmental changes in children. Knowledge of these normal variants is essential for both diagnosis and management of their elbow injuries. Radiography remains the first imaging modality of choice. Magnetic resonance imaging is excellent in evaluating lesions within the bone and soft tissues. In this pictorial essay, we provide insights into pediatric elbow imaging, show a range of entities specific to the pediatric elbow, and discuss diagnostic pitfalls that result from normal elbow growth in children.
Increasing Rates of RSV Hospitalization among Preterm Infants: A Decade of Data
Authors: Kong Amanda M. , Winer Isabelle H. , Zimmerman Nicole M. , Diakun David , Bloomfield Adam , Gonzales Tara , Fergie Jaime , Goldstein Mitchell , Krilov Leonard R.
Published: October 2021

Objective In 2014, the American Academy of Pediatrics (AAP) changed its policy on the use of respiratory syncytial virus immunoprophylaxis (RSV-IP) so that RSV-IP was no longer recommended for use among infants without other medical conditions born >29 weeks of gestational age (wGA). This study examines 10-year trends in RSV-IP and RSV hospitalizations among term infants and preterm infants born at 29 to 34 wGA, including the 5 RSV seasons before and 5 RSV seasons after the AAP guidance change.

Study Design A retrospective observational cohort study of a convenience sample of infants less than 6 months of age during RSV season (November–March) born between July 1, 2008, and June 30, 2019, who were born at 29 to 34 wGA (preterm) or >37 wGA (term) in the IBM MarketScan Commercial and Multi-State Medicaid databases. We excluded infants with medical conditions that would independently qualify them for RSV-IP. We identified RSV-IP utilization along with RSV and all-cause bronchiolitis hospitalizations during each RSV season. A difference-in-difference model was used to determine if there was a significant change in the relative rate of RSV hospitalizations following the 2014 policy change.

Results There were 53,535 commercially insured and 85,099 Medicaid-insured qualifying preterm infants and 1,111,670 commercially insured and 1,492,943 Medicaid-insured qualifying term infants. Following the 2014 policy change, RSV-IP utilization decreased for all infants, while hospitalization rates tended to increase for preterm infants. Rate ratios comparing preterm to term infants also increased. The relative rate for RSV hospitalization for infants born at 29 to 34 wGA increased significantly for both commercially and Medicaid-insured infants (1.95, 95% CI: 1.67–2.27, p <0.001; 1.70, 95% CI: 1.55–1.86, p <0.001, respectively). Findings were similar for all-cause bronchiolitis hospitalizations.

Conclusion We found that the previously identified increase in RSV hospitalization rates among infants born at 29 to 34 wGA persisted for at least 5 years following the policy change.

Key Points
Prolonged Operative Time Associated with Increased Healthcare Utilization after Open Reduction and Internal Fixation of Intra-Articular and Extra-Articular Distal Radial Fractures: An Analysis of 17,482 Cases
Authors: Scollan Joseph P. , Ohliger Erin , Emara Ahmed K. , Grits Daniel , McConaghy Kara , Ng Mitchell , Styron Joseph
Published: October 2021

Background The current literature does not contain a quantitative description of the associations between operative time and adverse outcomes after open reduction and internal fixation (ORIF) of distal radial fractures (DRF).

Questions/Purpose We aimed to quantify associations between DRF ORIF operative time and 1) 30-day postoperative health care utilization and 2) the incidence of local wound complications.

Methods The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for DRF ORIF cases (January 2012–December 2018). A total of 17,482 cases were identified. Primary outcomes included health care utilization (length of stay [LOS], discharge dispositions, 30-day readmissions, and reoperations) per operative-time category. Secondary outcome was incidence of wound complications per operative-time category. Multivariate regression was conducted to determine operative-time categories associated with increased risk while adjusting for demographics, comorbidities, and fracture type. Spline regression models were constructed to visualize associations.

Results The 121 to 140-minute category was associated with significantly higher risk of a LOS > 2 days (odds ration [OR]: 1.64; 95% confidence interval [CI]:1.1–2.45; p = 0.014) and nonhome discharge (OR: 1.72; 95% CI:1.09–2.72; p = 0.02) versus 41 to 60-minute category. The ≥ 180-minute category exhibited highest odds of LOS > 2 days (OR: 2.08; 95%CI: 1.33–3.26; p = 0.001), nonhome discharge disposition (OR: 1.87; 95% CI: 1.05–3.33; p = 0.035), and 30-day reoperation occurrence (OR: 3.52; 95% CI: 1.59–7.79; p = 0.002). There was no association between operative time and 30-day readmission (p > 0.05 each). Higher odds of any-wound complication was first detected at 81 to 100-minute category (OR: 3.02; 95% CI: 1.08–8.4; p = 0.035) and peaked ≥ 181 minutes (OR: 9.62; 95% CI: 2.57–36.0; p = 0.001). Spline regression demonstrated no increase in risk of adverse outcomes if operative times were 50 minutes or less.

Conclusion Our findings demonstrate that prolonged operative time is correlated with increased odds of health care utilization and wound complications after DRF ORIF. Operative times greater than 60 minutes seem to carry higher odds of postoperative complications.
Konzertierte Aktion Pflege: In der Summe sind die Ergebnisse positiv
Authors: Napp Barbara
Published: October 2021

Kennen Sie die Konzertierte Aktion Pflege? Vor wenigen Wochen wurde von den verantwortlichen Bundesministerien der zweite Zwischenbericht vorgelegt. An diesem wurde von Seiten der Pflegeverbände harsche Kritik geübt, der Bericht sei geprägt von Schönfärberei. Der Vorwurf: Vor Ende der Legislaturperiode sei es offenbar darum gegangen, Erfolge präsentieren zu können. Um beurteilen zu können, ob diese Kritik berechtigt ist, müssen wir den Blick auf die einzelnen Pflegesektoren richten. Nur so können die Ergebnisse differenziert eingeordnet werden.
Discursive structures and power relations in Covid-19 knowledge production
Authors: Bisiada Mario
Published: October 2021

This article critically examines the discourse around the Covid-19 pandemic to investigate the widespread polarisation evident in social media debates. The model of epidemic psychology holds that initial adverse reactions to a new disease spread through linguistic interaction. The main argument is that the mediation of the pandemic through social media has fomented the effects of epidemic psychology in the reaction to the Covid-19 pandemic by providing continued access to commentary and linguistic interaction. This social interaction in the absence of any knowledge on the new disease can be seen as a discourse of knowledge production, conducted largely on social media. This view, coupled with a critical approach to the power relations inherent in all processes of knowledge production, provides an approach to understanding the dynamics of polarisation, which is, arguably, issue-related and not along common ideological lines of left and right. The paper critiques two discursive structures of exclusion, the terms science and conspiracy theory, which have characterised the knowledge production discourse of the Covid-19 pandemic on social media. As strategies of dialogic contraction, they are based on a hegemonic view of knowledge production and on the simplistic assumption of an emancipated position outside ideology. Such an approach, though well-intentioned, may ultimately undermine social movements of knowledge production and thus threaten the very values it aims to protect. Instead, the paper proposes a Foucauldian approach that problematises truth claims and scientificity as always ideological and that is aware of power as inherent to all knowledge production.
Renewable approach to synthesizing ammonia using single-atom catalysts
Authors: Cockshott Anne
Published: October 2021

Manufacturing ammonia is a critical part of the global economy, requiring the development of renewable processes to replace current expensive and environmentally unfriendly ones.
Challenges in simulating and modeling the airborne virus transmission: A state-of-the-art review
Authors: Pourfattah Farzad , Wang Lian-Ping , Deng Weiwei , Ma Yong-Feng , Hu Liangquan , Yang Bo
Published: October 2021

Recently, the COVID-19 virus pandemic has led to many studies on the airborne transmission of expiratory droplets. While limited experiments and on-site measurements offer qualitative indication of potential virus spread rates and the level of transmission risk, the quantitative understanding and mechanistic insights also indispensably come from careful theoretical modeling and numerical simulation efforts around which a surge of research papers has emerged. However, due to the highly interdisciplinary nature of the topic, numerical simulations of the airborne spread of expiratory droplets face serious challenges. It is essential to examine the assumptions and simplifications made in the existing modeling and simulations, which will be reviewed carefully here to better advance the fidelity of numerical results when compared to the reality. So far, existing review papers have focused on discussing the simulation results without questioning or comparing the model assumptions. This review paper focuses instead on the details of the model simplifications used in the numerical methods and how to properly incorporate important processes associated with respiratory droplet transmission. Specifically, the critical issues reviewed here include modeling of the respiratory droplet evaporation, droplet size distribution, and time-dependent velocity profile of air exhaled from coughing and sneezing. According to the literature review, another problem in numerical simulations is that the virus decay rate and suspended viable viral dose are often not incorporated; therefore here, empirical relationships for the bioactivity of coronavirus are presented. It is hoped that this paper can assist researchers to significantly improve their model fidelity when simulating respiratory droplet transmission.
Optical constants of Al0.85Ga0.15As0.56Sb0.44 and Al0.79In0.21As0.74Sb0.26
Authors: Guo B. , Jones A. H. , Lee S. , Kodati S. H. , Liang B. , Xue X. , Pfiester N. A. , Schwartz M. , Winslow M. , Grein C. H. , Ronningen T. J. , Krishna S. , Campbell J. C.
Published: October 2021

Digital alloy Al0.85Ga0.15As0.56Sb0.44 and random alloy Al0.79In0.21As0.74Sb0.26 avalanche photodiodes with a 1-μm multiplication layer exhibit low excess noise under 543-nm laser illumination comparable to Si avalanche photodiodes. This has motivated a study of the optical characteristics of these materials. The absorption coefficients and complex refractive indices were extracted via variable-angle spectroscopic ellipsometry. Features of three semiconductor layer fitting approaches are compared, and a Kramers–Kronig-consistent basis spline function was chosen due to its flexibility and accuracy of approximating optical constants of quaternary materials. The external quantum efficiency has been calculated based on the extracted absorption coefficients and is shown to agree well with the measured external quantum efficiency.
Stabilization of thick, rhombohedral Hf0.5Zr0.5O2 epilayer on c-plane ZnO
Authors: Zheng Maoyuan , Yin Zhigang , Cheng Yong , Zhang Xingwang , Wu Jinliang , Qi Jing
Published: October 2021

Metastable rhombohedral hafnia-based ferroelectric films are emerging as a promising candidate in ferroelectric nonvolatile memory technologies, but the limited critical thickness impedes their applications. Herein, a 35-nm-thick rhombohedral Hf0.5Zr0.5O2 epilayer was stabilized on ZnO(0001) under an oxygen-deficient condition. Domain matching epitaxy, which facilitates the accommodation of misfit strain, allows the epitaxial growth of the (111)-oriented rhombohedral Hf0.5Zr0.5O2 film. We propose that a strong symmetry constraint is imposed on the epilayer at the initial epitaxial growth stage, i.e., the plane adjacent to ZnO(0001) should have a threefold symmetry. Although the bulk monoclinic phase is much more stable than the rhombohedral phase, our first principles calculations reveal that these two phases are energetically comparable with each other when this symmetry constraint is considered. Moreover, our results show that the incorporation of doubly charged oxygen vacancies is also powerful in shifting the energy balance between competing phases, making the metastable rhombohedral phase more stable.
Vibrational line shape effects in plasmon-enhanced stimulated Raman spectroscopies
Authors: Mandal Aritra , Ziegler L. D.
Published: October 2021

A density matrix treatment of plasmon-enhanced (PE) stimulated Raman spectroscopies is developed. Specifically, PE stimulated Raman Gain/Loss (PE-SRG/L) and coherent anti-Stokes Raman scattering (PE-CARS) due to monochromatic excitation and PE femtosecond stimulated Raman spectroscopy (PE-FSRS) are considered. A Lorentz oscillator model is used to explicitly describe the time dependence of plasmon-enhanced optical fields. These temporal characteristics are required for a density matrix based description of all plasmon-enhanced nonlinear molecular spectroscopies. Dispersive vibrational line shapes in PE-SRG/L and PE-FSRS spectra are shown to result primarily from terms proportional to the square of the complex optical field enhancement factor. The dependence on the plasmon resonance, picosecond and femtosecond pulse characteristics, and molecular vibrational properties are evident in the density matrix derived PE-FSRS intensity expression. The difference in signal detection mechanisms accounts for the lack of dispersive line shapes in PE spontaneous Raman spectroscopy. This density matrix treatment of PE-FSRS line shapes is compared with prior coupled wave results.
Geometry and dynamics of passive scalar structures in compressible turbulent mixing
Authors: Buchmeier Jonas , Bußmann Alexander , Gao Xiangyu , Bermejo-Moreno Iván
Published: October 2021

We present a structure-based numerical analysis of passive scalar mixing in decaying homogeneous isotropic turbulence (DHIT) and shock-turbulence interaction canonical configurations. The analysis focuses on the temporal evolution of ensembles of passive scalar structures, initialized as spheres of different sizes relative to the Taylor microscale. An algorithm is introduced to track the evolution of each individual structure and the interactions with other structures in the ensemble, relating changes in the surface geometry and the underlying physical processes (turbulent transport, scalar dissipation, and shock compression). The tracking algorithm is applied to datasets from shock-capturing direct numerical simulations of DHIT, with Taylor microscale Reynolds number Reλ=40 and turbulence Mach number Mt=0.2, and STI cases in which the turbulence is processed by a shock wave at Mach numbers M = 1.5 and 3.0. Temporal surface convolution increases for initially larger structures, resulting in a higher probability of locally hyperbolic geometries where breakup into smaller structures occurs. Shock-induced deformation of the structures amplifies breakup processes, enhancing mixing, particularly for larger structures. Mixing enhancement by the shock is manifested as an amplification of the surface-averaged scalar gradient, which increases for initially larger structures. The alignment between the scalar gradient and the most extensional strain-rate eigendirection on the scalar isosurfaces also increases across the shock. Larger magnitudes of the scalar gradient and its alignment with the most compressive strain-rate eigendirection correlate with flatter surface regions. Shock-induced structure compression increases the area coverage of flat regions, where the amplification of scalar gradient is localized.
Single-shot imaging of ultrafast all-optical magnetization dynamics with a spatiotemporal resolution
Authors: Zalewski T. , Stupakiewicz A.
Published: October 2021

We present a laboratory system for single-shot magneto-optical (MO) imaging of ultrafast magnetization dynamics with less than 8 fs temporal, micrometer spatial resolutions and a MO Faraday’s rotation sensitivity of 4 mdeg/μm. We create a stack of MO images repeatedly employing a single pair of pump and defocused probe pulses to induce and visualize MO changes in the sample. Both laser beams are independently wavelength-tunable, allowing for a flexible, resonant adjustable two-color pump and probe scheme. To increase the MO contrast, the probe beam is spatially filtered through a 50 μm aperture. We performed the all-optical switching experiment in Co-doped yttrium iron garnet films (YIG:Co) to demonstrate the capability of the presented method. We determine the spatiotemporal distribution of the effective field of photo-induced anisotropy, driving the all-optical switching of the magnetization in the YIG:Co film without an external magnetic field. Moreover, using this imaging method, we tracked the process of the laser-induced magnetization precession.
Simulations of hybrid charge-sensing single-electron-transistors and CMOS circuits
Authors: Tanamoto Tetsufumi , Ono Keiji
Published: October 2021

Single-electron transistors (SETs) have been extensively used as charge sensors in many areas, such as quantum computations. In general, the signals of SETs are smaller than those of complementary metal–oxide–semiconductor (CMOS) devices, and many amplifying circuits are required to enlarge the SET signals. Instead of amplifying a single small output, we theoretically consider the amplification of pairs of SETs, such that one of the SETs is used as a reference. We simulate the two-stage amplification process of SETs and CMOS devices using a conventional SPICE (Simulation Program with Integrated Circuit Emphasis) circuit simulator. Implementing the pairs of SETs into CMOS circuits makes the integration of SETs more feasible because of direct signal transfer from the SET to the CMOS circuits.
Ab initio study of nuclear quantum effects on sub- and supercritical water
Authors: Thomsen Bo , Shiga Motoyuki
Published: October 2021

The structures of water in the ambient, subcritical, and supercritical conditions at various densities were studied systematically by ab initio path integral molecular dynamics simulations. It was found that the nuclear quantum effects (NQEs) have a significant impact on the structure of hydrogen bonds in close contact, not only in the ambient condition but also in the sub- and supercritical conditions. The NQEs on the structure beyond the hydrogen bond contact are important in ambient water, but not much for water in the sub- and supercritical conditions. The NQEs are furthermore important for determining the number of hydrogen bonds in the ambient conditions, and this role is, however, diminished in the sub- and supercritical conditions. The NQEs do, nevertheless, show their importance in determining the intramolecular structure of water and the close contact structures of the hydrogen bonds, even at sub- and supercritical conditions. Using the RPBE-D3 functional, the computed radial distribution functions for ambient water are in excellent agreement with experimental data, upgrading our previous results using the BLYP-D2 functional [Machida et al., J. Chem. Phys. 148, 102324 (2018)]. The computed radial distribution functions for water in the sub- and supercritical conditions were carefully compared with experiment. In particular, we found that the first peak in hydrogen pair distribution functions matches only when the NQEs are taken into account.
Strain and ferroelectricity in wurtzite ScxAl1−xN materials
Authors: Clima Sergiu , Pashartis Christopher , Bizindavyi Jasper , McMitchell Sean R. C. , Houssa Michel , Van Houdt Jan , Pourtois Geoffrey
Published: October 2021

Density functional theory predicts an abrupt drop in the stability, in the kinetic barrier for polarization reversal and spontaneous polarization of a ScxAl1−xN wurtzite phase, when the Sc:Al ratio approaches 50:50. The same effect is obtained by the application of a tensile strain. The resulting polarization reversal barrier correlates with experimental coercive fields, and highly textured film measurements exhibit polarization values close to the theoretically predicted ones. Film thickness below 5 nm has a significant impact on the elastic properties.
Transcorrelated coupled cluster methods
Authors: Schraivogel Thomas , Cohen Aron J. , Alavi Ali , Kats Daniel
Published: October 2021

Transcorrelated coupled cluster and distinguishable cluster methods are presented. The Hamiltonian is similarity transformed with a Jastrow factor in the first quantization, which results in up to three-body integrals. The coupled cluster with singles and doubles equations on this transformed Hamiltonian are formulated and implemented. It is demonstrated that the resulting methods have a superior basis set convergence and accuracy to the corresponding conventional and explicitly correlated methods. Additionally, approximations for three-body integrals are suggested and tested.
Social media’s role in support networks among LGBTQ adolescents: a qualitative study
Authors: Berger Matthew N. , Taba Melody , Marino Jennifer L. , Lim Megan S. C. , Cooper Spring Chenoa , Lewis Larissa , Albury Kath , Chung Kon Shing Kenneth , Bateson Deborah , Skinner S. Rachel
Published: October 2021

Background Adolescents use social media more frequently than other age groups. Social media has been described as a safe environment for lesbian, gay, bisexual, transgender and queer and/or questioning (LGBTQ) adolescents. As part of mixed-methods research investigating the association between social networks and sexual agency, we present qualitative findings on how LGBTQ adolescents connect online to form support networks. Methods We recruited 30 adolescents aged 14–17 years who identified as LGBTQ in terms of their gender or attraction in the longitudinal Social Networks and Agency Project. Semi-structured interviews were conducted online or face-to-face across Australia. Thematic analysis was used to explore perceptions and experiences of participants in relation to social media use and relationships. Results Two overarching themes were identified: LGBTQ adolescents use social media for identity, relationships and wellbeing support. Social media is not always free of discrimination for LGBTQ adolescents. Many LGBTQ participants joined Facebook groups to connect with LGBTQ peers. Facebook was considered a vital support for those with mental health concerns including suicidal ideation. Participants gave and received support from group members, which was considered useful for those feeling isolated or victimised. LGBTQ adolescents formed friendships, romantic relationships and gained information on sex, relationships, and sexual health from these groups. Participants described negative experiences including discrimination within Facebook groups, mismanaged groups and exposure to anti-LGBTQ sentiments. Conclusion Social media is an environment where LGBTQ adolescents can connect, educate and support each other, which may have beneficial effects for this marginalised group. There remain issues with social media including discrimination against and within LGBTQ communities.
Optimisation of a pollen DNA metabarcoding method for diet analysis of flying-foxes (
Authors: Bell Karen L. , Batchelor Kathryn L. , Bradford Matt , McKeown Adam , Macdonald Stewart L. , Westcott David
Published: October 2021

Determining the diet of flying-foxes can increase understanding of how they function as pollinators and seed dispersers, as well as managing any negative impacts of large roosts. Traditional methods for diet analysis are time consuming, and not feasible to conduct for hundreds of animals. In this study, we optimised a method for diet analysis, based on DNA metabarcoding of environmental DNA (eDNA) from pollen and other plant parts in the faeces. We found that existing eDNA metabarcoding protocols are suitable, with the most useful results being obtained using a commercial food DNA extraction kit, and sequencing 350–450 base pairs of a DNA barcode from the internally transcribed spacer region (ITS2), with ~550 base pairs of the chloroplast rubisco large subunit (rbcL) as a secondary DNA barcode. A list of forage plants was generated for the little red flying-fox (Pteropus scapulatus), the black flying-fox (Pteropus alecto) and the spectacled flying-fox (Pteropus conspicillatus) from our collection sites across Queensland. The diets were determined to comprise predominantly Myrtaceae species, particularly those in the genera Eucalyptus, Melaleuca and Corymbia. With more plant genomes becoming publicly available in the future, there are likely to be further applications of eDNA methods in understanding the role of flying-foxes as pollinators and seed dispersers.
Deep learning the slow modes for rare events sampling
Authors: Bonati Luigi , Piccini GiovanniMaria , Parrinello Michele
Published: October 2021

Significance

The use of enhanced sampling simulations is essential in the study of complex physical, chemical, and biological processes. We devise a procedure that, by combining machine learning and biased simulations, removes the bottlenecks that hinder convergence. This approach allows different types of challenging processes to be studied in a near-blind way, thus extending significantly the scope of atomistic simulations.
Cryo-EM structure of the needle filament tip complex of theSalmonellatype III secretion injectisome
Authors: Guo Emily Z. , Galán Jorge E.
Published: October 2021

Significance

Many bacterial pathogens encode type III protein secretion machines, which have the capacity to inject bacterial proteins into host cells to promote virulence. An important component of these machines is the tip complex, a structure located at the end of the needle filament of the secretion machine. This structure is essential for the delivery of effector proteins into host cells. We have used cryoelectron microscopy to visualize at high resolution the tip complex of a type III secretion machine of the bacterial pathogenSalmonellaTyphimurium. This work provides important insight into the assembly and function of type III protein secretion machines and may provide the bases for the development of therapeutic strategies to combat infectious diseases.
A cantilever-based resonator for reconfigurable nanomechanical computing
Authors: Fang Jiawei , Zhang Pengcheng , Yang Rui , Wang Zenghui
Published: October 2021

As silicon transistors face challenges in scaling, nanoelectromechanical systems (NEMS) have emerged as a promising candidate for computing due to the ultralow power consumption and high-temperature compatibility. Yet there is still limited research about highly reconfigurable NEMS-based computing devices that integrate multiple functionalities into a single device. In this work, we present the design, simulation, and verification of a cantilever-based NEMS resonator for highly reconfigurable logic functions. Using a single resonator with multiple inputs, the device can be reconfigured to perform AND, OR, XOR, and NOT logic operations, by changing the combination of inputs. We use both DC and AC voltages as inputs, where AC inputs can be used for better reconfigurability, and DC inputs offer higher On/Off ratio. The cantilever structure has low rigidity and large dynamic range, and thus only requires 5 mV of AC drive to achieve relatively large vibration amplitude. This work presents a unique platform where a single NEMS resonator can be used for reconfigurable computing.
Spectral and intensity control of high energy terahertz radiation from bulk liquids
Authors: Rakesh Kumar V , Jana Kamalesh , Dey Indranuj , Chandra Vardhan K , Lad Amit D , Brown Jeffrey M , Gaarde Mette B , Couairon Arnaud , Ravindra Kumar G
Published: October 2021

High power, broadband terahertz (THz) radiation from liquids, excited by intense, femtosecond 800 nm laser pulses has been demonstrated recently, overturning the long held belief that liquids would not give such emission due to their absorption in the THz region. Given the widespread interest in the use of THz radiation for several applications and the energy and bandwidth limitations of existing sources, liquids are expected to attract great attention in the future. While the emission at tens of microjoules from liquids is very promising, it is important to explore whether control of the THz flux and spectrum is achievable by manipulating the laser or liquid parameters. In this paper we present results on manipulating the spectrum of THz radiation from liquids by chirping the input laser pulse and optimizing the THz output energy by laser chirp as well as optimizing the focal position. We demonstrate tunability by varying the chirp of the laser pulse and show that the THz emission predominantly comes from the region near the end of the liquid path, consistent with the absorption of THz radiation by liquids. This control gives us an opportunity to tune the THz radiation to suit experimental needs. We present simulations that support the results.
Mott transition, magnetic and orbital orders in the ground state of the two-band Hubbard model using variational slave-spin mean field formalism
Authors: Maurya Arun Kumar , Sarder Md Tahir Hossain , Medhi Amal
Published: October 2021

We study the ground state phase diagram of the degenerate two-band Hubbard model at integer fillings as a function of onsite Hubbard interaction U and Hund’s exchange coupling J. We use a variational slave-spin mean field method which allows symmetry broken states to be studied within the computationally less intensive slave-spin mean field formalism. The results show that at half-filling, the ground state at smaller U is a Slater antiferromagnet with substantial local charge fluctuations. As U is increased, the antiferromagnetic (AF) state develops a Heisenberg behavior, finally undergoing a first-order transition to a Mott insulating AF state at a critical interaction U
c which is of the order of the bandwidth. Introducing the Hund’s coupling J correlates the system more and reduces U
c drastically. At quarter-filling with one electron per site, the ground state at smaller U is paramagnetic metallic. At finite J, as interaction is increased beyond a lower critical value U
c1, it goes to a fully spin polarized ferromagnetic state coexisting with an antiferro-orbital order. Further increase in U beyond a higher critical value U
c2 results in the Mott insulating state where local charge fluctuation vanishes.
The accuracy of helium ion CT based particle therapy range prediction: an experimental study comparing different particle and x-ray CT modalities
Authors: Volz L , Collins-Fekete C-A , Bär E , Brons S , Graeff C , Johnson R P , Runz A , Sarosiek C , Schulte R W , Seco J
Published: October 2021

This work provides a quantitative assessment of helium ion CT (HeCT) for particle therapy treatment planning. For the first time, HeCT based range prediction accuracy in a heterogeneous tissue phantom is presented and compared to single-energy x-ray CT (SECT), dual-energy x-ray CT (DECT) and proton CT (pCT). HeCT and pCT scans were acquired using the US pCT collaboration prototype particle CT scanner at the Heidelberg Ion-Beam Therapy Center. SECT and DECT scans were done with a Siemens Somatom Definition Flash and converted to RSP. A Catphan CTP404 module was used to study the RSP accuracy of HeCT. A custom phantom of 20 cm diameter containing several tissue equivalent plastic cubes was used to assess the spatial resolution of HeCT and compare it to DECT. A clinically realistic heterogeneous tissue phantom was constructed using cranial slices from a pig head placed inside a cylindrical phantom (ø150 mm). A proton beam (84.67 mm range) depth-dose measurement was acquired using a stack of GafchromicTM EBT-XD films in a central dosimetry insert in the phantom. CT scans of the phantom were acquired with each modality, and proton depth-dose estimates were simulated based on the reconstructions. The RSP accuracy of HeCT for the plastic phantom was found to be 0.3 ± 0.1%. The spatial resolution for HeCT of the cube phantom was 5.9 ± 0.4 lp cm−1 for central, and 7.6 ± 0.8 lp cm−1 for peripheral cubes, comparable to DECT spatial resolution (7.7 ± 0.3 lp cm−1 and 7.4 ± 0.2 lp cm−1, respectively). For the pig head, HeCT, SECT, DECT and pCT predicted range accuracy was 0.25%, −1.40%, −0.45% and 0.39%, respectively. In this study, HeCT acquired with a prototype system showed potential for particle therapy treatment planning, offering RSP accuracy, spatial resolution, and range prediction accuracy comparable to that achieved with a commercial DECT scanner. Still, technical improvements of HeCT are needed to enable clinical implementation.