bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality of Life, Satisfaction, Occlusal Force, and Halitosis after Direct and Indirect Relining of Inferior Complete Dentures
Authors: Sônego Mariana Vilela , Neto Clóvis Lamartinede Moraes Melo , dos Santos Daniela Micheline , Moreno André Luiz de Melo , Bertoz André Pinheiro de Magalhães , Goiato Marcelo Coelho
Published: August 2021

Objective The aim of this study was to compare the direct relining technique with the indirect relining technique in relation to quality of life, satisfaction with the relining, occlusal force, and halitosis of users of acrylic complete dentures.

Materials and Methods Twenty bimaxillary edentulous individuals were selected. They had to use the same pair of complete dentures for a minimum of 1 year and a maximum of 5 years. The subjects were randomly divided in groups of direct relining and indirect relining of the inferior denture (n = 10). Both groups received the same silicone-based relining. The clinical tests verified the quality of life (Oral Health Impact Profile in edentulous individuals), the satisfaction with the relining, the occlusal force, and halitosis. The tests (halitosis and occlusal force) were performed initially (before the relining), immediately after the relining, and 30, 60, 90, and 180 days after the relining. The questionnaires (quality of life and satisfaction with the relining) were performed initially (before the relining), and 30, 60, 90, and 180 days after the relining.

Statistical Analysis Analysis of variance and the Tukey test were used (p < 0.05).

Results There was no statistical difference comparing the two techniques in all the evaluations (p < 0.05). There was a significant statistical difference for the factor of time in all clinical tests for each relining technique (p < 0.05). The quality of life and satisfaction with the relining increased significantly 30 days after the relining when compared with the initial time point, for both techniques (p < 0.05). The occlusal force increased significantly after 90 and 180 days when compared with the initial time point, for both techniques (p < 0.05). Halitosis decreased significantly immediately after the relining when compared with the initial time point, for both techniques (p < 0.05).

Conclusion Independent of the relining technique used, there was an increase in the quality of life, satisfaction with the relining, and occlusal force, as well as a reduction in the level of halitosis. Both techniques generated similar results and therefore can be options in clinical practice.
Effect of Remote Ischemic Conditioning on Bleeding Complications in Surgery: A Systematic Review and Meta-Analysis
Authors: Krag Andreas E. , Hvas Christine L. , Kiil Birgitte J. , Hvas Anne-Mette
Published: August 2021

Remote ischemic conditioning (RIC) is administered with an inflatable tourniquet by inducing brief, alternating cycles of limb ischemia and reperfusion. RIC possibly impacts the hemostatic system, and the intervention has been tested as protective therapy against ischemia-reperfusion injury and thrombotic complications in cardiac surgery and other surgical procedures. In the present systematic review, we aimed to investigate the effect of RIC on intraoperative and postoperative bleeding complications in meta-analyses of randomized controlled trials including adult patients undergoing surgery. A systematic search was performed on November 7, 2020 in PubMed, Embase, and the Cochrane Central Register of Controlled Trials. Randomized controlled trials comparing RIC versus no RIC in adult patients undergoing surgery that reported bleeding outcomes in English publications were included. Effect estimates with 95% confidence intervals were calculated using the random-effects model for intraoperative and postoperative bleeding outcomes. Thirty-two randomized controlled trials with 3,804 patients were eligible for inclusion. RIC did not affect intraoperative bleeding volume (nine trials; 392 RIC patients, 399 controls) with the effect estimate −0.95 [−9.90; 7.99] mL (p = 0.83). RIC significantly reduced postoperative drainage volume (seven trials; 367 RIC patients, 365 controls) with mean difference −83.6 [−134.9; −32.4] mL (p = 0.001). The risk of re-operation for bleeding was reduced in the RIC group (16 trials; 838 RIC patients, 839 controls), albeit not significantly, with the relative risk 0.65 [0.39; 1.09] (p = 0.10). In conclusion, RIC reduced postoperative bleeding measured by postoperative drainage volume in this meta-analysis of adult patients undergoing surgery.
Immunoexpression of CD34, CD117, and p53 in Hypocellular Bone Marrow Disorders
Authors: Sharma Pooja , Palta Anshu , Tahlan Anita , Kaur Manveen , Singh Ram
Published: August 2021

Objectives Hypocellular bone marrow (BM) disorders comprise heterogeneous entities associated with peripheral cytopenias and decreased production of hematopoietic cells in BM. This study was undertaken to analyze immunohistochemical expression of CD34, CD117, and p53 in morphologically diagnosed patients of hypocellular BM (aplastic anemia [AA], hypocellular myelodysplastic syndrome [h-MDS], and hypocellular acute myeloid leukemia [h-AML]).

Materials and Methods BM specimens were obtained from patients presenting with pancytopenia/bicytopenia. On 30 patients diagnosed as hypocellular BM, immunohistochemistry (IHC) for CD34, CD117, and p53 was performed.

Results BM cellularity was < 30% in all (100%) patients. Blast count was increased in h-MDS and h-AML. Features of dysplasia were noted in six (20%) patients. Out of these, three patients were diagnosed as h-MDS having bilineage/trilineage dysplasia, and the other three patients were of AA (11.5% patients) displaying only dyserythropoiesis. On IHC, percentage of BM CD34+ cells was increased in h-MDS+ h-AML (3.87 ± 0.86) as compared with AA (0.19 ± 0.15) and controls (0.81 ± 0.21), p = 0.01. Percentage of BM p53+ cells was also increased in h-MDS+ h-AML (2.9 ± 2.07) as compared with AA and controls, which did not show any p53+ cells, p = 0.0. No statistically significant difference was observed in the expression of CD117 in h-MDS+ h-AML (4.95 ± 3.40) compared with AA (4.49 ± 1.07), p = 0.99.

Conclusion The study demonstrates the usefulness of CD34 and p53 immunoexpression as an important ancillary method in distinguishing various hypocellular BM disorders, especially h-MDS and AA. However, the role of CD117 remains unclear and needs to be evaluated further by larger studies.
Early Neonatal Mortality among Babies Born with Spina Bifida in Finland (2000–2014)
Authors: Kancherla Vijaya , Mowla Sanjida , Räisänen Sari , Gissler Mika
Published: August 2021

Objective We examined early neonatal mortality risk, temporal trends, and selected infant and maternal factors associated with early neonatal mortality among all spina bifida-affected live births in Finland.

Study Design We linked multiregistry population-based data from the national registers in Finland for infants born with spina bifida from 2000 to 2014. Early neonatal mortality was defined as death in 0 to 6 days after birth. Early neonatal mortality risk and 95% confidence intervals (CI) was estimated by using the Poisson approximation of binomial distribution. Poisson regression was used to examine temporal trend in early neonatal mortality from 2000 to 2014 for spina bifida cases and all births in Finland. Selected infant and maternal characteristics were compared between cases that experienced early neonatal mortality and cases that did not. Exact logistic regression was used to estimate unadjusted odds ratios (uORs) and 95% confidence intervals (CIs).

Results A total of 181 babies were born alive with spina bifida in Finland during the study period; 61% had isolated spina bifida. Pooling all study years, 7.2% (95% CI: 4.2–12.4%) of all live-born cases experienced early neonatal death. There was a significant increase in early neonatal mortality among spina bifida births over the study period (p < 0.0001). Low gestational age (<37 weeks; uOR = 6.96; 95% CI: 1.86–29.01), cases occurring as a part of a syndrome (uOR = 125.67; 95% CI: 14.90 to >999.999), and advanced maternal age at gestation (≥35 years; uOR = 5.33; 95% CI: 1.21–21.87) were positively associated with early neonatal mortality.

Conclusion Using national data from Finland, we found high early neonatal mortality with increasing trend over birth period spanning 15 years (2000–2014), and unadjusted positive associations with some infant and maternal factors. Future studies should pool data from Nordic countries to increase study size allowing multivariable analysis.

Key Points
A refined measure of conditional maximum drawdown
Authors: Rossello Damiano , Lo Cascio Silvestro
Published: August 2021

Risks associated to maximum drawdown have been recently formalized as the tail mean of the maximum drawdown distribution, called Conditional Expected Drawdown (CED). In fact, the special case of average maximum drawdown is widely used in the fund management industry also in association to performance management. It lacks relevant information on worst case scenarios over a fixed horizon. Formulating a refined version of CED, we are able to add this piece of information to the risk measurement of drawdown, and then get a risk measure for processes that preserves all the good properties of CED but following more prudential regulatory and management assessments, also in term of marginal risk contribution attributed to factors. As a special application, we consider the conditioning information given by the all time minimum of cumulative returns.
Scanning SQUID microscopy in a cryogen-free dilution refrigerator
Authors: Low D. , Ferguson G. M. , Jarjour Alexander , Schaefer Brian T. , Bachmann Maja D. , Moll Philip J. W. , Nowack Katja C.
Published: August 2021

We report a scanning superconducting quantum interference device (SQUID) microscope in a cryogen-free dilution refrigerator with a base temperature at the sample stage of at least 30 mK. The microscope is rigidly mounted to the mixing chamber plate to optimize thermal anchoring of the sample. The microscope housing fits into the bore of a superconducting vector magnet, and our design accommodates a large number of wires connecting the sample and sensor. Through a combination of vibration isolation in the cryostat and a rigid microscope housing, we achieve relative vibrations between the SQUID and the sample that allow us to image with micrometer resolution over a 150 µm range while the sample stage temperature remains at base temperature. To demonstrate the capabilities of our system, we show images acquired simultaneously of the static magnetic field, magnetic susceptibility, and magnetic fields produced by a current above a superconducting micrometer-scale device.
New design yields robust large-area framing camera
Authors: Lewis Amy , Baker Stuart , Corredor Andrew , Fegenbush Logan , Fitzpatrick Zak , Jones Michael , O’Flarity Kevin , Walters Katie , Claus Liam , Sanchez Marcos
Published: August 2021

Framing cameras provide a discrete series of images over a short period of time in a manner that mimics a high-speed movie camera but with individual shutter times that must be extremely short in order to capture freeze-frame images of rapidly evolving phenomena such as high-explosive shock-driven ejecta, dynamic compression of metals, and high-velocity fluid flow. The Nevada National Security Site has designed and fielded a new, large-area, gated framing camera called Kraken. The camera design emphasized manufacturability and flexibility by improving imager yield and creating a camera architecture to shorten design cycles. Design strategies and field data are presented.
X-ray multi-probe data acquisition: A novel technique for laser pump x-ray transient absorption spectroscopy
Authors: Kinigstein Eli D. , Jennings Guy , Kurtz Charles A. , March Anne Marie , Zuo Xiaobing , Chen Lin X. , Attenkofer Klaus , Zhang Xiaoyi
Published: August 2021

We report the development and implementation of a novel data acquisition (DAQ) technique for synchrotron-based laser pump X-ray Transient Absorption (XTA) spectroscopy, called X-ray Multi-Probe DAQ (XMP DAQ). This technique utilizes high performance analog to digital converters and home-built software to efficiently measure and process the XTA signal from all x-ray pulses between laser excitations. XMP DAQ generates a set of time resolved x-ray absorption spectra at thousands of different pump–probe time delays simultaneously. Two distinct XMP DAQ schemes are deployed to accommodate different synchrotron storage ring filling patterns. Current Integration (CI) DAQ is a quasi-analog technique that implements a fitting procedure to extract the time resolved absorption intensity from the averaged fluorescence detector response. The fitting procedure eliminates issues associated with small drifts in the voltage baseline and greatly enhances the accuracy of the technique. Photon Counting (PC) DAQ is a binary technique that uses a time resolved histogram to calculate the XTA spectrum. While PC DAQ is suited to measure XTA data with closely spaced x-ray pulses (∼10 ns) and a low count rate (<1 detected photon/pulse), CI DAQ works best for widely spaced pulses (tens of ns or greater) with a high count rate (>1 detected photon/pulse). XMP DAQ produces a two-dimensional XTA dataset, enabling efficient quantitative analysis of photophysical and photochemical processes from the sub-nanosecond timescale to 100 μs and longer.
Influence of pyrolysis temperature on bio-oil produced from hazelnut shells: Physico-chemical properties and antioxidant activity of wood vinegar and tar fraction
Authors: Chen Aihui , Liu Xifeng , Zhang Haibin , Wu Hao , Xu Dong , Li Bo , Zhao Chenxi
Published: August 2021

This study focuses on the physico-chemical properties and antioxidant activity of wood vinegar and tar fraction in bio-oil produced from hazelnut shell pyrolysis at 400–1000 °C. In all cases, temperature plays a key role in the two fraction characteristics in bio-oil; phenols are absolutely dominant compounds, accounting for over 41 wt. % in wood vinegar and above 50 wt. % in tar. The hydroxyl radical scavenging experiment revealed that the higher phenol content resulted in the stronger antioxidant activity, and tar contained more phenolic compounds, which should have shown more antioxidant activity compared with wood vinegar, but under the influence of tar complex composition and properties, the hydroxyl radical binding reactions were severely blocked, which led to less antioxidant activity, and wood vinegar showed better potential as a natural antioxidant.
Plasma processing for advanced microelectronics beyond CMOS
Authors: Marchack N. , Buzi L. , Farmer D. B. , Miyazoe H. , Papalia J. M. , Yan H. , Totir G. , Engelmann S. U.
Published: August 2021

The scientific study of plasma discharges and their material interactions has been crucial to the development of semiconductor process engineering and, by extension, the entire microelectronics industry. In recent years, the proliferation of the big data business model has led to heightened interest in technology candidates with the potential to supplant CMOS architectures in critical metrics such as computational capacity or power consumption. These novel technologies share many common material elements with existing logic and memory devices, but the impact of mass fabrication techniques on their performance is largely unknown due to differences in the underlying physics of their operation. Two components are thus vital to this endeavor: fundamental evaluation of any emerging plasma process interactions and the ability to tailor any aspect of the plasma process necessary to produce the desired specifications. In this article, we review relevant advances in the study of plasma-induced damage mechanisms as well as characterization methods such as diagnostic probes and simulation tools. We also provide an outlook for the application of techniques such as plasma doping, area-selective etch/deposition, and heterogeneous integration. The frontiers of any new computing paradigms can only be explored through a focus on atomic scale engineering, and progress in the field of plasma science supplies the necessary toolset.
The Sakaguchi–Kuramoto model in presence of asymmetric interactions that break phase-shift symmetry
Authors: Manoranjani M. , Gupta Shamik , Chandrasekar V. K.
Published: August 2021

The celebrated Kuramoto model provides an analytically tractable framework to study spontaneous collective synchronization and comprises globally coupled limit-cycle oscillators interacting symmetrically with one another. The Sakaguchi–Kuramoto model is a generalization of the basic model that considers the presence of a phase lag parameter in the interaction, thereby making it asymmetric between oscillator pairs. Here, we consider a further generalization by adding an interaction that breaks the phase-shift symmetry of the model. The highlight of our study is the unveiling of a very rich bifurcation diagram comprising of both oscillatory and non-oscillatory synchronized states as well as an incoherent state: There are regions of two-state as well as an interesting and hitherto unexplored three-state coexistence arising from asymmetric interactions in our model.
Dynamics of an unbalanced circular foil and point vortices in an ideal fluid
Authors: Mamaev Ivan S. , Bizyaev Ivan A.
Published: August 2021

This paper addresses the problem of the motion of an unbalanced circular foil and point vortices in an ideal incompressible fluid. Using Bernoulli's theorem for unsteady potential flow, the force due to the pressure from the fluid on the foil is obtained for an arbitrary vortex motion. A detailed analysis is made of the case of free vortex motion in which a Hamiltonian reduction by symmetries is performed. For the resulting system, relative equilibria corresponding to the motion of an unbalanced foil and a vortex in a circle or in a straight line are found and their stability is investigated. New examples of stationary configurations of a vortex and a foil are given. Using a Poincaré map, it is also shown that in the general case of an unbalanced circular foil the reduced system exhibits chaotic trajectories.
Reconstruction of numerical inlet boundary conditions using machine learning: Application to the swirling flow inside a conical diffuser
Authors: Véras Pedro , Balarac Guillaume , Métais Olivier , Georges Didier , Bombenger Antoine , Ségoufin Claire
Published: August 2021

A new approach to determine proper mean and fluctuating inlet boundary conditions is proposed. It is based on data driven techniques, i.e., machine learning approach, and its goal is to use any known information about the downstream flow to reconstruct the unknown or incomplete inlet boundary conditions for a numerical simulation. The European Research Community On Flow, Turbulence And Combustion (ERCOFTAC) test case of the swirling flow inside a conical diffuser is investigated. Despite its relatively simple geometry, it constitutes a very challenging test case for numerical simulations due to incomplete experimental data and to the delicate balance between core flow recirculation and boundary layer separation. Simulations are performed using both Reynolds averaged Navier–Stokes (RANS) and large-eddy simulations (LES) turbulence methods. The mean velocity and turbulence kinetic energy profiles obtained with the machine learning approach in RANS are found to be in very good agreement with the experimental measurements and the numerical predictions are greatly improved as compared to the previous results using basic inlet boundary conditions. They are indeed comparable to the best previous RANS using empirical ad hoc inlet conditions to accurately simulate the downstream flow. In LES, in addition to the mean velocity profiles, the machine learning approach also allows us to properly reconstruct the fluctuating part of the turbulent field. In particular, the methodology allows us to circumvent the lack of turbulent correlations associated with classical inlet synthetic turbulence.
Impact of visible light and humidity on the stability of high-power light emitting diode packaging material
Authors: Shabir Abdul , Tan Cher Ming
Published: August 2021

There are many advantages of LEDs in energy and environmental conservation, but their short life in many outdoor applications prompt a necessity to have a detailed understanding of their degradations to prolong their lifetime, which can also conserve LED material and even expand their applications. Using ab initio density functional theory formulation, we identify the detail paths of the LED degradation in outdoor applications. We discovered that the main stressors are humidity and the light that is emitted from the LED chip itself. This is rather ironical. A mathematical model is developed based on the ab initio study, and excellent experimental agreements are found. With this model, we can predict the situations where no and slow degradations can be achieved, and these are verified experimentally here. We can also predict quantitatively the time to a specific degradation severity. Quality index of the housing material for LEDs can also be determined.
Exploring the structure of atom-precise silver–palladium bimetallic clusters prepared via improved single-pot co-reduction synthesis protocol
Authors: Sulaiman Kazeem O. , Purves Randy W. , Scott Robert W. J.
Published: August 2021

Designing atom-precise bimetallic clusters with a relatively cost-effective and more abundant metal than Au (i.e., Ag) is desirable for the development of heterogeneous bimetallic cluster catalysts for industrial applications. Atom-precise Ag-based bimetallic clusters, which are analogs of the well-studied Au based clusters, are yet to be fully explored as catalysts. Establishing the Pd loading limit and the position of the Pd dopant in AgPd bimetallic clusters will further give an insight into the structure–activity relationships for these atom-precise AgPd heterogeneous catalysts. In this study, an improved single-pot co-reduction strategy was employed to prepare the bimetallic clusters, which were then characterized by mass spectrometry, x-ray photoelectron spectroscopy (XPS), and x-ray absorption spectroscopy (XAS) to identify the loading and position of the dopant metal. Our results show that only a single dopant Pd atom can be incorporated, and in comparison with monometallic Ag25 clusters, the absorption peaks of Ag24Pd1(SPhMe2)182− bimetallic clusters are blue shifted due to the incorporation of Pd. The XPS and XAS results show that the Ag24Pd1(SPhMe2)182− bimetallic clusters have multivalent Ag(0) and Ag(I) atoms and surprisingly show Pd(II) species with significant Pd–S bonding, despite the prevailing wisdom that the Pd dopant should be in the center of the cluster. The XAS results show that the singly doped Pd atom predominantly occupies the staple position, albeit we cannot unambiguously rule out the Pd atom in an icosahedral surface position in some clusters. We discuss the ramifications of these results in terms of possible kinetically vs thermodynamically controlled cluster formation.
Epitaxial pillar–matrix nanocomposite thin films of Bi–Ti–Fe–O and CoFe2O4 grown on SrTiO3 (110)
Authors: Kawahira Y. , Harada R. , Maruyama S. , Koganezawa T. , Yasui S. , Itoh M. , Matsumoto Y.
Published: August 2021

Controlling nanostructures and crystallographic orientations in epitaxial nanocomposite thin films are important for tuning their physical properties. Here, we present epitaxial nanocomposite thin films of (110) oriented CoFe2O4 (CFO) and (1110) oriented Bi5Ti3FeO15 (BTFO15) grown on SrTiO3 (110) substrates with a vertically aligned pillar–matrix type structure. The size and density of CFO pillars embedded in the BTFO matrix were controlled by the growth temperature and CFO concentration. Moreover, BTFO takes intergrowth phases with the general formula of Bi4Ti3O12 • nBiFeO3 (n = 1–∼1.5) depending on the growth temperature. Scanning probe analysis on the ferroelectric properties of BTFO15–CFO nanocomposite thin films suggested that the BTFO has a switchable out-of-plane polarization component originating from the tilted orientation of its a–b plane polarization. For high CFO pillar density, however, a non-negligible number of conductive paths which might be formed at the pillar–matrix interface are likely to prevent the polarization reversal.
Fermi level controlled point defect balance in ion irradiated indium oxide
Authors: Borgersen Jon , Magnus Johansen Klaus , Vines Lasse , von Wenckstern Holger , Grundmann Marius , Kuznetsov Andrej Yu.
Published: August 2021

Fermi level controlled point defect balance is demonstrated in ion irradiated indium oxide (In2O3). Specifically, our observations can be sub-divided into the formation of isolated Frenkel pairs and secondary defects, correlated with an increase and decrease in resistance, respectively. Importantly, by considering the net charge contribution from the most energetically stable Frenkel pair configurations, we explain the data trends for low doses and determine an upper limit for the Fermi level pinning. Moreover, by comparing the corresponding number of generated carriers with the ballistic defect generation rates, we estimate the dynamic annealing efficiency. Further irradiation toward higher doses is consistent with the buildup of secondary defects. As such, the present data may be of practical use in a variety of In2O3 device applications requiring predictions of its radiation tolerance. In a broader perspective, the present methodology may be valuable for benchmarking defect simulation data in semiconductors in general.
Simulation of convective combustion reactions in PBX based on DEM–CPM
Authors: Wang Shuo , Liang Wen , Lu Fangyun , Chen Rong
Published: August 2021

Convective combustion is a characteristic process in the violent evolution of polymer-bonded explosives (PBX), which increases the reaction and causes rapid pressurization, high reaction violent explosion, or deflagration to detonation. Thus, simulations of convective combustion reactions are necessary to predict the risks associated with violence properly. There is rapid pressurization in the crack and flame penetration that are the main characteristics of convective combustion. Traditional numerical simulation methods are not applicable to simulate PBX convective combustion reactions. Therefore, in this paper, a discrete element method coupled with the corpuscular method was proposed, combined with the Ward-Son-Brewster (WSB) burn model. By using this method, the dynamic mechanical responses of PBX, the reaction products, and the combustion of PBX are modeled by the discrete element, gas particle, and WSB combustion mode, respectively. This coupled method has been validated by the simulation of the slot-pressurization experiment. Furthermore, the reaction evolution after ignition in PBX was simulated, as well as the process of flame penetration into charge. The analysis of flame penetration into the charge contributes to a deeper understanding of the violent event of PBX.
Evidence of spin reorientation and anharmonicity in kagome ferromagnet Fe3Sn2
Authors: Wu Peng , Song Jiuhui , Yu Xiaoxiang , Wang Yihao , Xia Kang , Hong Bin , Zu Lin , Du Yinchang , Vallobra Pierre , Liu Fengguang , Torii Shuki , Kamiyama Takashi , Xiong Yimin , Zhao Weisheng
Published: August 2021

Recently discovered massive Dirac fermions and room temperature skyrmions in the ferromagnetic kagome metal Fe3Sn2 have attracted extensive attention due to the potential applications in topological and spintronic devices. Because of its centrosymmetric lattice, the topological spin texture in Fe3Sn2 arises primarily from the competition between anisotropy and exchange interaction. In this Letter, we have identified the spin-reorientation at around 80 K by the magnetization and AC-susceptibility measurements. The evolution of the anisotropy is revealed by neutron powder diffraction data from 18 to 700 K, where the “breathing”-like kagome structure evolves into an ideal kagome lattice at higher temperature. Meanwhile, the deviation between the experimental and calculated results on heat capacity at high temperature and the softening of optical phonon modes in Raman spectra suggest the presence of anharmonic phonons in Fe3Sn2, which is responsible for the degeneracy of lattice thermal conductivity at high temperature. Our study indicates that Fe3Sn2 possesses a promising future in the design and development of topological, spintronic as well as thermoelectric devices.
Effect of transverse displacement of charged particle beams on quantum electrodynamic processes during their collision
Authors: Filipovic M. , Baumann C. , Pukhov A.M. , Samsonov A.S. , Kostyukov I.Yu.
Published: August 2021

Collisions of ultrarelativistic electron beams are considered using full-scale 3D particle-in-cell simulation. In this process, the particles can be affected by the superintense fields of the counterpropagating beam, and the interaction can pass to the regime of nonperturbative quantum electrodynamics. In this experimentally unexplored regime, the emission of photons and the production of electron – positron pairs are extremely probable processes. It is shown that due to the transverse displacement of the beams and an increase in the number of particles located in the region of the field maximum, it is possible to increase the yield of both photons and electron – positron pairs.
Laser-plasma acceleration of polarised electrons up to energies of several TeV
Authors: Pugacheva D.V. , Andreev N.E.
Published: August 2021

The process of multistage acceleration of polarised electrons in the wakefield of a relativistic femtosecond laser pulse is investigated. The main mechanism of the growth of slice emittance for a moderately nonlinear regime of laser-plasma acceleration is demonstrated. The main conditions for setting the initial parameters of the electron bunch are determined, which allow minimising the mixing of the phases of betatron oscillations of particles in the bunch slice and the emittance growth during acceleration. The method of smooth input of an electron bunch into the accelerating stage and its smooth removal from this stage is studied, which allows the main characteristics of the bunch to be preserved, such as emittance and polarisation, for further particle transportation and acceleration. The effect of the radiation friction force and the radiation polarisation mechanism on the process of particle depolarisation in acceleration to energies of ∼4 TeV in model fields characteristic of moderately nonlinear and strongly nonlinear regimes of laser-plasma acceleration is considered.
Generation of electron – positron pairs by laser-ion implosion of a target with a spherical microbubble inside
Authors: Serebryakov D.A. , Kostyukov I.Yu. , Murakami M.
Published: August 2021

Laser targets with microbubbless have recently been intensely studied, including with the aim of generating superintense electromagnetic fields. Under the action of laser radiation, ion beams are formed in the target, converging to the centre of the microbubbles. In the central region, the ion density can be several times higher than the target density, leading to the generation of an extremely intense electric field and high-energy ions. Using PIC simulation, the dynamics of target electrons is investigated taking into account the effects of quantum electrodynamics (QED) and the development of a QED cascade in the intense field region. It is shown that an increase in the electron temperature leads to a much more efficient formation of electron – positron pairs. The contribution of bremsstrahlung to the generation of photons in the central region of the microbubbles is analysed. It is found that the contribution of bremsstrahlung is insignificant in comparison with the synchrotron mechanism of electron emission in the collective field of ions.
Specific features of radiation emitted upon tunnel ionisation of atoms in extremely intense laser fields
Authors: Popruzhenko S.V. , Kalymbetov E.B.
Published: August 2021

Radiation emitted by fast electrons in the process of multiple tunnel ionisation of heavy atoms in the focus of a laser pulse with extreme intensity exceeding 1022W cm−2is studied. It is shown that the spectral-angular distribution of emitted photons in a wide range of angles is qualitatively determined by relations of the synchrotron radiation theory. The dependences of the number and the characteristic frequency of emitted photons on the laser pulse parameters are estimated. The obtained results can be used to determine the maximum laser intensity in the focus.
Generation of IR radiation in the interaction of an ultrashort laser pulse with a gas jet
Authors: Golovanov A.A. , Kostyukov I.Yu.
Published: August 2021

We consider the generation of IR radiation during the interaction of a high-power ultrashort laser pulse with a gas jet using numerical simulation by the particle-in-cell method. The laser pulse parameters correspond to the capabilities of the PEARL sub-petawatt laser facility in Nizhny Novgorod (Russia) when using the compression after compressor approach (CafCA). It is demonstrated that about 1 % of the energy can be converted into radiation in the wavelength range of 5 – 10 μm.
Design of the front-end system for a subexawatt laser of the XCELS facility
Authors: Mukhin I.B. , Soloviev A.A. , Perevezentsev E.A. , Shaykin A.A. , Ginzburg V.N. , Kuzmin I.V. , Mart’yanov M.A. , Shaikin I.A. , Kuzmin A.A. , Mironov S.Yu. , Yakovlev I.V. , Khazanov E.A.
Published: August 2021

A concept of the front-end system of the XCELS (eXawatt Center for Extreme Light Studies) facility is presented. Its design is aimed at achieving high stability of laser radiation parameters and possibility of their control in a wide range. Optically synchronised chirped signal (wavelength 910 nm, bandwidth more than 100 nm, and duration ∼3 ns) and pump (wavelength 1054 nm, bandwidth ∼1 nm, and duration ∼4 ns) pulses for XCELS parametric amplifiers will be implemented at the output of the front-end system. Chirped femtosecond pulses with energies above 100 mJ [no more than 15 fs long after compression, with carrier-envelope phase (CEP) stabilisation] will have a repetition rate up to 100 Hz, which will allow one to implement active energy stabilisation and to minimise the angular jitter of the emitted beam at the XCELS output. The application of picosecond pumping in the parametric amplifier of the front-end system should provide a high contrast of femtosecond pulses. The pump pulse will be linearly frequency-modulated; this approach will not affect the parametric amplification efficiency but make it possible to use spectral methods to control the pump pulse shape in order to form a pulse of specified shape at the output of power amplifiers, even under conditions of their strong saturation.
Illustrated Plant Glossary
Authors: Mayfield Enid
Published: August 2021

The Illustrated Plant Glossary is a comprehensive glossary of over 4000 terms related to plant sciences, featuring many superb colour illustrations to aid understanding.

The topics covered in this glossary include anatomy, angiosperms, bryophytes, chemistry, cytology, family specific terms, ferns and fern allies, flowers, fruit, genetics, gymnosperms, habit and growth, habitat and ecology, indumentum, inflorescence, leaves, reproduction, roots, seeds, systematics and more.

The Illustrated Plant Glossary is a must-have reference for plant scientists, plant science teachers and students, libraries, horticulturalists, ecologists, gardeners and naturalists.
Is Australia’s environmental legislation protecting threatened species? A case study of the national listing of the greater glider
Authors: Ashman Kita R. , Watchorn Darcy J. , Lindenmayer David B. , Taylor Martin F. J.
Published: August 2021

Effective environmental legislation that mitigates threats and strengthens protection are critical in arresting the decline of global biodiversity. We used the national listing of an Australian marsupial, the greater glider (Petauroides spp.), vulnerable to extinction under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC), as a case study to evaluate the effectiveness of legislation for protecting threatened species habitat. We quantified the extent of greater glider habitat destroyed (or extensively modified) due to deforestation and logging in Queensland and New South Wales (NSW), and logging in Victoria, 2 years before (2014–2016) and after (2016–2018) EPBC listing. We quantified the extent of greater glider habitat that burned in the 2019–2020 wildfires. Destruction of habitat increased in NSW and Queensland after the species was listed as vulnerable (NSW: 7602 ha/annum c.f. 7945 ha/annum; Qld: 1501 ha/annum c.f. 5919 ha/annum). In Victoria, the amount of habitat logged remained relatively consistent pre- and post-listing (4916.5 ha logged pre-listing c.f. 4758.5 ha logged post-listing). Australia-wide, we estimate that 29% of greater glider habitat burned in the 2019–2020 wildfires. Fire severity was severe or extreme in 37% of greater glider habitat that burnt, suggesting that few gliders would persist in these areas. We demonstrate that since EPBC listing, greater glider habitat destruction and population decline has continued as a result of human activities, both directly (i.e. deforestation and logging) and indirectly (i.e. severe wildfire facilitated by human-induced climate change). We recommend that state and federal protections should be strengthened urgently to better conserve threatened species and the environment.
Histone H3K27 methylation–mediated repression of
Hairy
regulates insect developmental transition by modulating ecdysone biosynthesis
Authors: Yang Yan , Zhao Tujing , Li Zheng , Qian Wenliang , Peng Jian , Wei Ling , Yuan Dongqin , Li Yaoyao , Xia Qingyou , Cheng Daojun
Published: August 2021

Significance

PRC2-mediated H3K27 methylation functions in epigenetic transcriptional repression and is involved in various developmental processes in eukaryotes. Insect developmental transitions are regulated by juvenile hormone (JH) and ecdysone in an antagonistic manner. Here, we used
Bombyx
and
Drosophila
to show that PRC2-mediated H3K27 methylation at the
Hairy
gene involved in JH signaling suppresses
Hairy
transcription in the prothoracic gland (PG), which is required for steroidogenic enzyme transcription, ecdysone biosynthesis, and the larval–pupal transition. JH impairs PRC2-mediated H3K27 methylation in the PG. Our findings establish an essential role for PRC2-mediated H3K27 methylation in hormone-mediated developmental transitions and further deepen our understanding of epigenetic regulatory mechanisms underlying the antagonistic actions of JH and ecdysone in insects.
Strong within-host selection in a maternally inherited obligate symbiont:
Buchnera
and aphids
Authors: Perreau Julie , Zhang Bo , Maeda Gerald P. , Kirkpatrick Mark , Moran Nancy A.
Published: August 2021

Significance

Many animals depend on maternally transmitted symbiotic bacteria that provide nutrients or other benefits. The evolution of these symbionts is complicated: natural selection can act on hosts, favoring symbionts that increase host reproduction, or on symbionts, favoring symbionts that spread within hosts. Furthermore, transmission bottlenecks can facilitate the spread of mutations deleterious to both. By measuring changes in frequencies of symbiont genotypes within individual insect matrilines, we estimated within-host selection and transmission bottleneck size. Results revealed surprisingly strong selection, with some symbiont genotypes more successful in colonizing progeny, as well as a severe transmission bottleneck, consistent with observations of deleterious mutation accumulation in symbiont genomes. Findings elucidate the forces driving evolution of heritable symbionts and generating their distinctive genomic features.
Robust high-temperature potassium-ion batteries enabled by carboxyl functional group energy storage
Authors: Lu Xianlu , Pan Xuenan , Zhang Dongdong , Fang Zhi , Xu Shang , Ma Yu , Liu Qiao , Shao Gang , Fu Dingfa , Teng Jie , Yang Weiyou
Published: August 2021

Significance

Distinctively different from the popularly reported works, an energy storage mechanism is proposed for exploring robust high-temperature potassium-ion batteries (PIBs) with high cycle stability. This is based on an example of p-phthalic acid with two carboxyl functional groups as the redox centers. The cycle stabilities achieved under both low and high current densities are the best among those of high-temperature PIBs reported previously.
Stories behind post-verbal negation clustering
Authors: Mithun Marianne
Published: August 2021

Post-verbal markers of negation were once thought to be rare cross-linguistically, but as more has been learned about more languages, it has become clear that such markers occur in a number of parts of the world. Moreover, they often appear in areal clusters, suggesting that language contact may play a role in their development. Such a cluster can be seen in a well-known linguistic area of North America, Indigenous Northern California. Languages in the area show parallel negative constructions, but without shared substance. Here it is shown how such parallelisms may have come about.
Language of the unheard: police-recorded protests in South Africa, 1997–2013
Authors: Bekker Martin
Published: August 2021

South Africa remains beset by protest. Notwithstanding an impressive literature, quantifying protests remains problematic; most attempts extrapolate from samples or media-derived data sets. Applying machine learning to the world’s largest publicly available, single-country public-event database – the South African Police Service’s Incident Registration Information System – the article classifies 150,000 events into type and levels of ‘tumult’. The author provides the first holistic picture of all police-reported protest in South Africa over a given period (1997–2013), showing a count increase (partly confirming the ‘rebellion of the poor’ thesis), while more nuanced measures (i.e. protestors per capita) demonstrate a less urban and tumultuous phenomenon than previously theorised.
Intracellular wetting mediates contacts between liquid compartments and membrane-bound organelles
Authors: Kusumaatmaja Halim , May Alexander I. , Knorr Roland L.
Published: August 2021

Protein-rich droplets, such as stress granules, P-bodies, and the nucleolus, perform diverse and specialized cellular functions. Recent evidence has shown the droplets, which are also known as biomolecular condensates or membrane-less compartments, form by phase separation. Many droplets also contact membrane-bound organelles, thereby functioning in development, intracellular degradation, and organization. These underappreciated interactions have major implications for our fundamental understanding of cells. Starting with a brief introduction to wetting phenomena, we summarize recent progress in the emerging field of droplet–membrane contact. We describe the physical mechanism of droplet–membrane interactions, discuss how these interactions remodel droplets and membranes, and introduce "membrane scaffolding" by liquids as a novel reshaping mechanism, thereby demonstrating that droplet–membrane interactions are elastic wetting phenomena. “Membrane-less” and “membrane-bound” condensates likely represent distinct wetting states that together link phase separation with mechanosensitivity and explain key structures observed during embryogenesis, during autophagy, and at synapses. We therefore contend that droplet wetting on membranes provides a robust and intricate means of intracellular organization.
JAML promotes CD8 and γδ T cell antitumor immunity and is a novel target for cancer immunotherapy
Authors: McGraw Joseph M. , Thelen Flavian , Hampton Eric N. , Bruno Nelson E. , Young Travis S. , Havran Wendy L. , Witherden Deborah A.
Published: August 2021

T cells are critical mediators of antitumor immunity and a major target for cancer immunotherapy. Antibody blockade of inhibitory receptors such as PD-1 can partially restore the activity of tumor-infiltrating lymphocytes (TILs). However, the activation signals required to promote TIL responses are less well characterized. Here we show that the antitumor activity of CD8 and γδ TIL is supported by interactions between junctional adhesion molecule–like protein (JAML) on T cells and its ligand coxsackie and adenovirus receptor (CXADR) within tumor tissue. Loss of JAML through knockout in mice resulted in accelerated tumor growth that was associated with an impaired γδ TIL response and increased CD8 TIL dysfunction. In mouse tumor models, therapeutic treatment with an agonistic anti-JAML antibody inhibited tumor growth, improved γδ TIL activation, decreased markers of CD8 TIL dysfunction, and significantly improved response to anti–PD-1 checkpoint blockade. Thus, JAML represents a novel therapeutic target to enhance both CD8 and γδ TIL immunity.
Electromagnetically induced transparency in a V-system with 87Rb vapour in the hyperfine Paschen-Back regime
Authors: Higgins Clare R , Hughes Ifan G
Published: August 2021

We observe electromagnetically induced transparency (EIT) in a V-system in a thermal rubidium-87 vapour in the hyperfine Paschen-Back regime, realised with a 0.6 T axial magnetic field. In this regime energy levels are no longer degenerate and EIT features from different initial states are distinct, which we show produces a much cleaner feature than without a magnetic field. We compare our results to a model using the time-dependent Lindblad master equation, and having averaged over a distribution of interaction times, see good qualitative agreement for a range of pump Rabi frequencies. Excited state decay into both ground states is shown to play a prominent role in the generation of the transparency feature, which arises mainly due to transfer of population into the ground state not coupled by the probe beam. We use the model to investigate the importance of coherence in this feature, showing that its contribution is more significant at smaller pump Rabi frequencies.
Elastic and inelastic particles scattering by dust acoustic soliton. A new oscillatory process in dusty plasma
Authors: Trukhachev F M , Gerasimenko N V , Vasiliev M M , Petrov O F
Published: August 2021

The parameters of scattering (reflection) of charged particles by the leading edge of a dust acoustic soliton are analyzed. The soliton profile is calculated using the Sagdeev pseudopotential approach. To analyze the motion of charged particles, the Newton’s second law is used. It is shown theoretically that the charged particle scattering can be elastic and inelastic. The nature of scattering significantly depends on the presence of dissipation. In the dissipative case, charged particles scattering is the process of an oscillatory nature. It is shown that it can be considered as a new type of oscillations of charged particles in plasma. The parameters of the oscillations are calculated both numerically (nonlinear case) and analytically (within the linear approximation). Theoretical results are compared with known experimental results, as well as the applied aspect is stated.