bluuebunny/crossref_metadata_2025 huggingface dataset:
Time of flight measurements of energy and density of laser induced Mg plasma ions and investigation of ablated surface morphology
Authors: Batool Amna , Bashir Shazia , Hayat Asma , Akram Mahreen , Mahmood Khaliq , Javed Mubashir , Hussain Fida , Butt Shariqa Hassan , Ahmad Haroon , Irfan Zulaikha , Dawood Asadullah
Published: January 2021

The energy and density measurements of laser induced Mg plasma ions have been performed by employing a Faraday cup as an ion collector by using the time of flight method. A Nd:YAG laser (532 nm, 8 ns) has been employed as an irradiation source at irradiances ranging from 4.5 GW/cm2 to 8.1 GW/cm2. For the first time, two distinct peaks of ions with the time delay of ns and μs have been identified for low-Z metal corresponding to fast and slow ions. It is revealed that both the energy and density of Mg plasma ions are increased with increasing laser irradiance and are decreased with the increasing distance between the collector and the target. The density of slow ions is 4–12 times higher than the density of fast ions for the selected irradiances. However, the energy of slow ions is in the range of 100's of eV and the energy of fast ions is in the range of 10's of keV. The anisotropic behavior and forward peaking of plasma are confirmed by the investigation of the angular distribution of ions. The plasma assisted laser ablated morphology is investigated by scanning electron microscopy (SEM) analysis. SEM analysis reveals the formation of cavities, cones, and spikes. The increasing trend of ion density and energy with increasing laser irradiance is correlated with the increased ablated areas and number density of cones.
Multiplexed lock-in thermography
Authors: Kopera Bernd A. F. , Retsch Markus
Published: January 2021

Many modern measurement methods for heat transfer work in the frequency domain. A certain average temperature rise in the sample is unavoidable if the sample can only be heated, e.g., by an intensity modulated light source. This average temperature rise influences the measured thermal properties because they are, in general, temperature dependent. Here, we explore square waves and multiplexed sine waves with the goal of reducing the average temperature rise. We apply these signals to lock-in thermography and show the feasibility of a simultaneous measurement at multiple frequencies. In addition, we propose the use of the Goertzel algorithm to efficiently extract individual spectral components from the temperature signal.
Effects of interphase boundaries in Ginzburg–Landau one-dimensional model of two-phase states in clamped systems
Authors: Levanyuk Arkady P. , Minyukov Sergey A. , Burc Misirlioglu I. , Baris Okatan M.
Published: January 2021

Previous Landau-type models of two-phase state formation in clamped systems whose material exhibits first-order phase transitions in free state neglects the existence of interphase boundaries. Here, we take them into account in the framework of a Ginzburg–Landau one-dimensional model to study the dependence of characteristics of the two-phase state on system size. Unlike earlier works, we find that the transition to the two-phase state from both the symmetrical and nonsymmetrical phases is not continuous but abrupt. For a one-dimensional system with length L studied in this work, we show that the formation of two-phase state begins with a region whose size is proportional to L. The latent heat of the transition is also proportional to L so that the specific latent heat goes to zero as L→∞, recovering the earlier result for infinite systems. The temperature width of the two-phase region decreases with decreasing of L, but we are unable to answer the question about the critical length for two-phase state formation because the approximation used in analytical calculations is valid for sufficiently large L. A region of small values of L was studied partially to reveal the limits of validity of the analytical calculations. The main physical results are also obtainable within a simple approximation that considers the energy of interphase boundary as a fixed value, neglecting its temperature dependence and the thickness of the boundary. A more involved but consistent treatment provides the same results within the accepted approximation and sheds light on the reason of validity of the simplified approach.
A high-throughput method to characterize membrane viscosity of flowing microcapsules
Authors: Lin Tao , Wang Zhen , Lu Ruixin , Wang Wen , Sui Yi
Published: January 2021

Microcapsules have many industrial applications and also serve as a widely used mechanical model of living biological cells. Characterizing the viscosity and elasticity of capsules at a high-throughput rate has been a classical challenge, since this is a time-consuming process in which one needs to fit the time-dependent capsule deformation to theoretical predictions. In the present study, we develop a novel efficient method, by integrating a deep convolutional neural network with a high-fidelity mechanistic capsule model, to predict the membrane viscosity and elasticity of a microcapsule from its dynamic deformation when flowing in a branched microchannel. Compared with a conventional inverse method, the present approach can increase the prediction throughput rate by five orders of magnitude while maintaining the same level of prediction accuracy. We also demonstrate that the present approach can deal with capsules with large deformation in inertial flows.
Probing the high mixing efficiency events in a lock-exchange flow through simultaneous velocity and temperature measurements
Authors: Agrawal Tanmay , Ramesh Bhaarath , Zimmerman Spencer J. , Philip Jimmy , Klewicki Joseph C.
Published: January 2021

Gravity currents produced by a lock-exchange flow are studied using high-resolution molecular tagging techniques. Instead of employing salt to produce density stratification, an initial temperature difference is introduced in the system to generate the ensuing gravity currents. The experiments focus on the interface between the hot and cold fluids to characterize the resultant mixing across the interface. The present measurements spatially resolve the flow to smaller than the Kolmogorov scale and close to the Batchelor scale. This enables reasonably accurate estimates of velocity and density gradients. The measured density (temperature) distribution allowed estimation of the background potential energy of the flow that is used to quantify mixing. These measurements yield a mixing efficiency of about 0.13 with a standard deviation of 0.05 for the present Reynolds number range [Re≤O(104)]. An analysis combining flow visualization and quantitative measurements reveals that spatially local values of high mixing efficiency occur after the occurrence of certain dissipative stirring events. These events, largely associated with vortical overturns, are commonly observed near the interface between the two fluids and are a precursor to locally efficient mixing.
Thermodynamics of shear-induced phase transition of polydisperse soft particle glasses
Authors: Khabaz Fardin , Bonnecaze Roger T.
Published: January 2021

The thermodynamics of the shear-induced phase transition of soft particle glasses is presented. Jammed suspensions of soft particles transform into a layered phase in a strong shear flow from a stable glassy phase at lower shear rates. The thermodynamics of the two phases can be computed based on the elastic energy and excess entropy of the system. At a critical shear rate, the elastic energy, the excess entropy, the free energy, the temperature, and the shear stress undergo discontinuous jumps at the phase transitions from the glassy to the layered phase. An effective temperature is defined from the derivative of the elastic energy and the excess entropy. The Helmholtz free energy is constructed using the elastic energy, excess entropy, and derived temperature. At a fixed shear rate, there is no equilibrium between the states. However, at a fixed temperature, the glassy and layered states may coexist, as indicated by the equality of their Helmholtz free energies. While this first-order phase transition is possible, it cannot be observed in simple shear because the stress is the same in both phases at the same temperature. Thus, shear banding cannot be observed in this system. Finally, an equation of state, which relates the shear stress to the excess entropy, is presented. This equation of state shows that all dynamical properties (e.g., shear-induced diffusivity and first and second normal stresses) of these jammed non-Brownian suspensions can be determined solely by measuring the shear stress.
Gate-tunable the interface properties of GaAs–WSe2 (1D–2D) vdWs heterojunction for high-responsivity, self-powered photodetector
Authors: Chen Xue , Jiang Bei , Wang Dengkui , Li Guoli , Wang Hailu , Wang Hao , Wang Fang , Wang Peng , Liao Lei , Wei Zhipeng
Published: January 2021

Integrated mixed-dimensional (MD) van der Waals (vdWs) heterojunctions for self-powered photodetectors have attracted intense attention. Performances of these photodetectors are highly dependent on the interface properties, including the semiconductor–metal interface and the semiconductor–semiconductor interface. To date, how to balance the interface properties remains to be explored. Here, we explore a straightforward strategy to balance the interface properties of the MD-vdWs heterojunction photodetector, by tuning the Fermi level of ambipolar two-dimensional material with a gate bias. The effectiveness of gate-tunable interface properties is verified by a GaAs-WSe2 MD vdWs heterojunction self-powered photodetector with different metal contacts. Under the gate biasing, the responsivity is enhanced from 122.55 mA/W to 510.98 mA/W in the GaAs–WSe2 heterojunction photodetector with the Au/Cr electrodes, which is better than the state-of-the-art GaAs-based self-powered photodetectors. This work provides a simple and effective method to fabricate high-responsivity, self-powered heterojunction photodetectors by gate-tunable interface properties.
High output power density and strong vibration durability in a modified barbell-shaped energy harvester based on multilayer Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals
Authors: Liu Jinfeng , Gao Xiangyu , Qiu Chaorui , Qiao Liao , Yang Jingya , Ma Ming , Song Kexin , Guo Haisheng , Xu Zhuo , Li Fei
Published: January 2021

Traditional piezoelectric energy harvesters are made of piezoelectric ceramics with a cantilever structure, which show a low output energy density. Thus, they are difficult to meet the requirements for self-powered electronics. Herein, we report a modified barbell-shaped piezoelectric energy harvester (BSPEH) based on two d33-mode cuboid Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 multilayer single crystal stacks (ten wafers with a thickness of 0.5 mm and d33 ∼ 1300 pC/N). Due to the electrically parallel and series connections of multilayer piezoelectric elements and the high figure-of-merit d33 × g33 of the single crystal, the maximum power density of BSPEH could reach 39.7 mW cm−3 (under an acceleration of 5 g), which is much higher than that of traditional cantilever piezoelectric energy harvesters (CPEHs), ∼0.1 mW cm−3. A maximum output voltage of 50.4 Vp–p was obtained when two crystal stacks are connected in series, and a maximum output current of 880 µA can be obtained when two crystal stacks are connected in parallel. Furthermore, the energy harvesting properties of BSPEH stay almost the same after 106 vibration cycles, while the properties of CPEH decrease 20% after 105 vibration cycles. This work indicates that BSPEH has a great potential in the application of wireless sensor networks for realizing the self-power of the equipment.
Significant bonding rearrangements triggered by Mg4 clusters
Authors: Vos Eva , Corral Inés , Montero-Campillo M. Merced , Mó Otilia
Published: January 2021

The structure, stability, and bonding of the complexes formed by the interaction of Mg4 clusters and first row Lewis bases, namely, ammonia, water, and hydrogen fluoride, have been investigated through the use of high-level G4 single-reference and CASPT2 multireference formalisms. The adducts formed reflect the high electrophilicity of the Mg4 cluster through electron density holes in the neighborhood of each metallic center. After the adduct formation, the metallic bonding of the Mg4 moiety is not significantly altered so that the hydrogen shifts from the Lewis base toward the Mg atoms lead to new local minima with enhanced stability. For the particular case of ammonia and water, the global minima obtained when all the hydrogens of the Lewis base are shifted to the Mg4 moiety have in common a very stable scaffold with a N or an O center covalently tetracoordinated to the four Mg atoms, so the initial bonding arrangements of both reactants have completely disappeared. The reactivity features exhibited by these Mg4 clusters suggest that nanostructures of this metal might have an interesting catalytic behavior.
Anti-inflammatory effects of low temperature atmospheric plasma on acute pancreatitis induced by L-arginine in rats
Authors: Sun Yuan-song , Wang Qi , Li He , Yang Min , Jin Tao
Published: January 2021

Acute pancreatitis (AP), a sterile inflammation in local pancreas, is well-known as one of the most serious abdominal diseases. It could develop into a systemic inflammation if there is lack of instant supervision. Thus, it is important to find an effective method to solve this clinical challenge. The purpose of our work is to study the anti-inflammatory effect of low temperature atmospheric plasma (LTAP) on AP in vivo, and two treatment doses, namely, 30 s and 60 s, were used in our experiment. The optical emission spectroscopy assay proved that the LTAP produced by an arc discharge reactor contains reactive oxygen and nitrogen species. The histopathologic result showed that the LTAP treatment for 60 s can significantly mitigate AP as compared with the group treated for 30 s. Moreover, the quantity of inflammation cells treated by the LTAP treatment for 60 s and 30 s was markedly reduced, while the 60 s treatment displayed a better suppress effect on AP. Taken together, our study indicated that LTAP can be used as a promising strategy to alleviate AP.
Ab initio predictions of graphite-like phase with anomalous grain boundaries and flexoelectricity from collapsed carbon nanotubes
Authors: Hu Chongze , Dernov Andrei , Xu Hao , Drozdov Grigorii , Dumitrică Traian
Published: January 2021

Although large-radius carbon nanotubes (CNTs) are now available in macroscopic quantities, little is known about their condensed phase. Large-scale density functional theory calculations predict a low energy phase in which the same-diameter “dog-bone” collapsed CNTs form a graphite-like phase with complex, anomalous grain boundaries (GBs). The excess GB volume does not prevent the strong van der Waals coupling of the flattened CNT sides into AB stacking. The associated GB energetics is dominated by the van der Waals energy penalty and high curvature bending of the loop CNT edges, which exhibit reactivity and flexoelectricity. The large density and superior mechanical rigidity of the proposed microstructural organization as well as the GB flexoelectricity are desirable properties for developing ultra-strong composites based on large-radius CNTs.
Elastically tuned defect mode within a cholesteric elastomer doped with metallic nano-spheres
Authors: Reyes Guillermo , Reyes Juan Adrian
Published: January 2021

A composite material, formed by a cholesteric elastomer slab, doped with randomly but uniformly distributed metallic nano-spheres, is studied. The cholesteric elastomer has a twist jump defect consisting of a finite discontinuity in the helical angle of the structure. The transmittance and reflectance spectra of the elastomer sample are studied when circularly polarized electromagnetic waves are impinging, while it is stretched by the action of an externally imposed agent. It has been observed that the co-polarized and cross-polarized transmittance and reflectance depend on the wavelength of the impinging wave and the amount of metallic spheres parameterized by the filling factor, strain, and magnitude of the twist defect. Additionally, we have found that the position of the line defect within the band reflection is red-shifted either by increasing the filling factor or stretching the sample.
Chromaticity manipulation of indoor photovoltaic cells
Authors: Chen Zhi-Hao , Yin Hang , Ho Johnny Ka Wai , Cui Li-Yong , So Shu Kong , Hao Xiao-Tao
Published: January 2021

Organic photovoltaic cells are appealing as indoor illumination harvesters to drive off-grid electronics in the Internet of things. However, a desirable output power usually requires expansive and dark active layers to absorb sufficient incident photons. The deployment of such large-scale dark objects is detrimental to the elaborately designed indoor lighting environment and affects human visual perceptions. Here, we propose a free-contact strategy to adjust the chromaticity of the transmitted indoor light by applying one-dimensional photonic crystals. Combining photonic crystals with various transmittances outside the photovoltaic cells, the spectral power distribution of the transmitted light can be precisely manipulated to realize a broad and consecutive color modulation covering the region from blue to orange. For certain photonic crystals, the chromaticity of propagated light can be recovered close to the light source. This work presents a solution to relieve light-disturbing in the application of organic photovoltaic cells under indoor illuminations.
Effect of Mo monoatomic interlayer on magnetic properties of in-plane anisotropic Nd-Fe-B/Mo/FeCo nanocomposite multilayered films
Authors: Koike Kunihiro , Ohashi Kazuki , Suzuki Takuya , Okita Chihiro , Inaba Nobuyuki , Kato Hiroaki , Itakura Masaru , Hara Shigeo , Saito Yu , Okubo Susumu , Ohta Hitoshi
Published: January 2021

The Nd-Fe-B/Mo/Fe-Co multilayered films on MgO(001) were fabricated by UHV sputtering method. The as-deposited films showed soft magnetic properties with weak perpendicular magnetic anisotropy, and after annealing above 650°C, these films showed in-plane magnetic anisotropy, good squareness, and hard magnetic properties with high coercivity of about 8 kOe. The (220) peak of Nd2Fe14B was identified in the XRD pattern after annealing of the film, which means that the c-axis, which is the easy axis of magnetization, points in the plane of the film, consistent with the measurement of the magnetization curve. The positive peak of ΔM plot of in-plane direction of the film annealed at 800°C was shown. This result suggests existence of exchange coupling between the Nd-Fe-B and Fe-Co layers in the in-plane anisotropic multilayered film with monoatomic Mo interlayer.
Robustness of the remanent magnetic domain pattern formation and associated stripe-bubble transitions in Co/Pt multilayers against field sequencing
Authors: Gentillon Aaron , Richards Carson , Ortiz-Flores Luis A. , Metzner Jeremy , Montealegre David , Healey Matthew , Cardon Kelsey , Westover Andrew , Hellwig Olav , Chesnel Karine
Published: January 2021

Thin ferromagnetic [Co/Pt] multilayers with perpendicular magnetic anisotropy exhibit a variety of nanoscopic magnetic domain patterns at remanence, from long interlaced stripes to lattices of bubbles, depending on the multilayer structure but also on the magnetic history of the sample. For optimized structural parameters, stripe-bubble transitions accompanied by drastic increases in domain density have been observed when the magnitude of the previously applied perpendicular field Hm is finely tuned throughout the hysteresis loop. Here, we investigate the robustness of these morphological transitions against field sequencing and field cycling. We conducted this study on [Co(x)/Pt(7Å)]N=50 where x varies from 4 to 60 Å. We mapped the morphological transition with Hm varying from 0 to 9 T, following both an ascending sequence (0 → 9 T) and a descending sequence (9 T → 0). We found that the optimal field Hm = H* at which the domain density is maximized and its associated maximal density n* are not significantly affected by the field sequencing direction. We have also investigated possible pumping effects when cycling the applied field at the value H*. We found that n* remains relatively stable through field cycling, and much more stable in the bubble state, compared to longer stripe states. The observed robustness of these morphological transitions against field sequencing and field cycling is of crucial importance for potential magnetic recording applications.
Regulation of salt-stressed sunflower (Helianthus annuus) seedling's water status by the coordinated action of Na+/K+ accumulation, nitric oxide, and aquaporin expression
Authors: Kumari Archana , Bhatla Satish C.
Published: January 2021

Among abiotic stresses, salt stress is a major threat to crop production all over the world. Present work demonstrates the profuse accumulation of Na+ in 2-day-old, dark-grown sunflower (Helianthus annuus L.) seedlings roots in response to salt stress (NaCl). The pattern of K+ accumulation in response to salt stress is similar to that of Na+ but on relatively lower scale. Application of nitric oxide (NO) donor (DETA) scales down Na+ accumulation in salt-stressed seedlings. The impact of NO donor on K+ accumulation is, however, different in control and salt-stressed seedling roots. In control seedlings, it enhances K+ accumulation, whereas, it gets reduced in salt-stressed seedlings. Specialised channels called ‘aquaporins’ (AQPs) play a major role maintaining the water status and transport across plant parts under salt-stress. Thus, accumulation of plasma-membrane intrinsic proteins (PIPs) and tonoplast-intrinsic proteins (TIPs), localised on plasma-membrane and vacuolar-membrane, respectively was undertaken in 2-day-old, dark-grown seedling roots. Salt stress increased the abundance of these isoforms, whereas, NO application resulted in decreased accumulation of PIP2 and TIP1. PIP1 and TIP2 isoforms remained undetectable. Present work thus, puts forward a correlation between AQP expression and ions (Na+ and K+) homeostasis in response to salt stress and NO.
Cell-phone traces reveal infection-associated behavioral change
Authors: Vigfusson Ymir , Karlsson Thorgeir A. , Onken Derek , Song Congzheng , Einarsson Atli F. , Kishore Nishant , Mitchell Rebecca M. , Brooks-Pollock Ellen , Sigmundsdottir Gudrun , Danon Leon
Published: January 2021

Significance

Infectious disease control critically depends on surveillance and predictive modeling of outbreaks. We argue that routine mobile-phone use can provide a source of infectious disease information via the measurements of behavioral changes in call-detail records (CDRs) collected for billing. In anonymous CDR metadata linked with individual health information from the A(H1N1)pdm09 outbreak in Iceland, we observe that people moved significantly less and placed fewer, but longer, calls in the few days around diagnosis than normal. These results suggest that disease-transmission models should explicitly consider behavior changes during outbreaks and advance mobile-phone traces as a potential universal data source for such efforts.
Reassessment of the phylogenetic relationships of the late Miocene apes
Hispanopithecus
and
Rudapithecus
based on vestibular morphology
Authors: Urciuoli Alessandro , Zanolli Clément , Almécija Sergio , Beaudet Amélie , Dumoncel Jean , Morimoto Naoki , Nakatsukasa Masato , Moyà-Solà Salvador , Begun David R. , Alba David M.
Published: January 2021

Significance

Reconstructing the phylogenetic relationships of extinct apes is challenging due to their fragmentary fossil record and the recurrent independent evolution of morphological features. Given the relevance of the phylogenetic signal of the bony labyrinth, here we assess the phylogenetic affinities of the late Miocene great apes
Hispanopithecus
and
Rudapithecus
by studying their inner ear morphology. Our results are consistent with the distinct generic status of these dryopiths, which further differ from the derived condition of orangutans and most closely resemble African apes. However, the latter appear largely primitive (similar to the last common ancestor of great apes and humans). Hence, our results do not conclusively favor a closer relationship with African apes as opposed to great apes as a whole.
SIRT7-dependent deacetylation of NPM promotes p53 stabilization following UV-induced genotoxic stress
Authors: Ianni Alessandro , Kumari Poonam , Tarighi Shahriar , Simonet Nicolas G. , Popescu Daniela , Guenther Stefan , Hölper Soraya , Schmidt Andreas , Smolka Christian , Yue Shijing , Krüger Marcus , Fiorillo Claudia , Vaquero Alejandro , Bober Eva , Braun Thomas
Published: January 2021

Significance

We discovered that the histone/protein deacetylase SIRT7, which is the only member of the mammalian sirtuin family residing primarily in the nucleolus, stabilizes p53 in response to UV-induced DNA damage by enabling binding of deacetylated NPM to MDM2/HDM2. The study unveils a crucial mechanism by which the nucleolus controls cellular stress responses. Furthermore, it characterizes SIRT7 as a potent regulator of cellular stress and offers opportunities to manipulate cellular p53 levels, which is important for the development of antitumor therapies.
The diversity bonus in pooling local knowledge about complex problems
Authors: Aminpour Payam , Gray Steven A. , Singer Alison , Scyphers Steven B. , Jetter Antonie J. , Jordan Rebecca , Murphy Robert , Grabowski Jonathan H.
Published: January 2021

Significance

Groups can collectively achieve an augmented cognitive capability that enables them to effectively tackle complex problems. Importantly, researchers have hypothesized that this group property—frequently known as collective intelligence—may be improved in functionally more diverse groups. This paper illustrates the importance of diversity for representing complex interdependencies in a social-ecological system. In an experiment with local stakeholders of a fishery ecosystem, groups with higher diversity—those with well-mixed members from diverse types of stakeholders—collectively produced more complex models of human–environment interactions which were more closely matched scientific expert opinions. These findings have implications for advancing the use of local knowledge in understanding complex sustainability problems, while also promoting the inclusion of diverse stakeholders for increasing management success.
A protease-mediated mechanism regulates the cytochrome
c
6
/plastocyanin switch in
Synechocystis
sp. PCC 6803
Authors: García-Cañas Raquel , Giner-Lamia Joaquín , Florencio Francisco J. , López-Maury Luis
Published: January 2021

Significance

After the appearance of oxygenic photosynthesis, iron (Fe) became oxidized, and its solubility and availability were greatly decreased. This generated a problem for most organisms since they are strongly dependent on Fe, especially photosynthetic organisms. In response, organisms evolved alternatives to Fe-containing proteins such as plastocyanin, a copper protein that substitutes for cytochrome
c
6
in photosynthesis. Expression of these two proteins in cyanobacteria is regulated by Cu availability, but the regulatory system remains unknown. Herein, we describe the regulatory system for these alternative proteins in photosynthesis in cyanobacteria. The mechanism involves a transcription factor (PetR) and a membrane protease (PetP) that degrades PetR in the presence of Cu.
Structural insights into a dimeric Psb27-photosystem II complex from a cyanobacterium
Thermosynechococcus vulcanus
Authors: Huang Guoqiang , Xiao Yanan , Pi Xiong , Zhao Liang , Zhu Qingjun , Wang Wenda , Kuang Tingyun , Han Guangye , Sui Sen-Fang , Shen Jian-Ren
Published: January 2021

Significance

Photosystem II (PSII) is a light-driven water:plastoquinone oxidoreductase in oxygenic photosynthetic organisms. Several inactive PSII intermediates are involved in the biogenesis of the multisubunit PSII complexes as well as in their repair after unavoidable oxidative damage targeted to PSII under light. Psb27 is one of the assembly factors associated with inactive PSII intermediate and plays important roles in the biogenesis/repair of PSII. Here, we report the structure of a dimeric Psb27-PSII from a thermophilic cyanobacterium
Thermosynechococcus vulcanus
by cryo-electron microscopy. Our results reveal the location and binding properties of Psb27 in the intermediate PSII and show the structural differences between the intermediate and native PSII. These results provide important clues for the roles of Psb27 in the biogenesis/repair of PSII.
Drosophila
Sex Peptide controls the assembly of lipid microcarriers in seminal fluid
Authors: Wainwright S. Mark , Hopkins Ben R. , Mendes Cláudia C. , Sekar Aashika , Kroeger Benjamin , Hellberg Josephine E. E. U. , Fan Shih-Jung , Pavey Abigail , Marie Pauline P. , Leiblich Aaron , Sepil Irem , Charles Philip D. , Thézénas Marie L. , Fischer Roman , Kessler Benedikt M. , Gandy Carina , Corrigan Laura , Patel Rachel , Wigby Stuart , Morris John F. , Goberdhan Deborah C. I. , Wilson Clive
Published: January 2021

Significance

Seminal fluid plays a critical role in reprogramming female physiology and behavior to promote male reproductive success. We show, in the fruit fly, that specific seminal proteins, including the archetypal “female-reprogramming” molecule Sex Peptide, are stored in male seminal secretions in association with large neutral lipid-containing microcarriers, which rapidly disperse in females. Related structures are also observed in other Sex Peptide-expressing
Drosophila
species. Males lacking Sex Peptide have structurally defective microcarriers and exhibit abnormal transfer of many seminal proteins to females. Our data reveal that this key signaling molecule in
Drosophila
seminal fluid is also a microcarrier assembly factor that modulates transfer of other seminal factors and that this may be a more evolutionarily ancient role of this protein.
Timing matters when correcting fake news
Authors: Brashier Nadia M. , Pennycook Gordon , Berinsky Adam J. , Rand David G.
Published: January 2021

Countering misinformation can reduce belief in the moment, but corrective messages quickly fade from memory. We tested whether the longer-term impact of fact-checks depends on when people receive them. In two experiments (total
N =
2,683), participants read true and false headlines taken from social media. In the treatment conditions, “true” and “false” tags appeared before, during, or after participants read each headline. Participants in a control condition received no information about veracity. One week later, participants in all conditions rated the same headlines’ accuracy. Providing fact-checks after headlines (
debunking
) improved subsequent truth discernment more than providing the same information during (
labeling
) or before (
prebunking
) exposure. This finding informs the cognitive science of belief revision and has practical implications for social media platform designers.
Performance of molecular crystals in conversion of light to mechanical work
Authors: Mahmoud Halabi Jad , Ahmed Ejaz , Sofela Samuel , Naumov Panče
Published: January 2021

Significance

Over recent years, the increased reporting on mechanically responsive molecular crystals has accumulated an extensive library of organic crystalline materials with diverse nature-like energy-transduction mechanisms. While the chemistry behind the underlying molecular transformations is elaborate, these single crystals' work-producing capacity remains underexplored due to the need for customized testing setups suitable for delicate organic microstructures. Using a simple setup, we lay out a set of performance metrics by which we characterize the light-driven actuation in azobenzene crystals as an exemplary chemical class of dynamic molecular crystals. This work may guide the quantification of responsive molecular crystals' actuation potential and act as an invitation to ramp up interdisciplinary interest to further develop this class of materials into controlled all-organic actuating elements.
Universal law for the vibrational density of states of liquids
Authors: Zaccone Alessio , Baggioli Matteo
Published: January 2021

An analytical derivation of the vibrational density of states (DOS) of liquids, and, in particular, of its characteristic linear in frequency low-energy regime, has always been elusive because of the presence of an infinite set of purely imaginary modes—the instantaneous normal modes (INMs). By combining an analytic continuation of the Plemelj identity to the complex plane with the overdamped dynamics of the INMs, we derive a closed-form analytic expression for the low-frequency DOS of liquids. The obtained result explains, from first principles, the widely observed linear in frequency term of the DOS in liquids, whose slope appears to increase with the average lifetime of the INMs. The analytic results are robustly confirmed by fitting simulations data for Lennard-Jones liquids, and they also recover the Arrhenius law for the average relaxation time of the INMs, as expected.
DNA methylation-linked chromatin accessibility affects genomic architecture in
Arabidopsis
Authors: Zhong Zhenhui , Feng Suhua , Duttke Sascha H. , Potok Magdalena E. , Zhang Yiwei , Gallego-Bartolomé Javier , Liu Wanlu , Jacobsen Steven E.
Published: January 2021

Significance

Plant DNA methylation, which occurs in three sequence contexts (CG, CHG, and CHH, where H refers to A, T, or C), is established and maintained by different mechanisms. In this study, we present genome-wide chromatin accessibility profiles of
Arabidopsis
mutants that are deficient in CG, CHG, and/or CHH methylation. Through a combination of DNA methylation, chromatin accessibility, and higher-order chromosome conformation profiling of these mutants, we uncover links between DNA methylation, chromatin accessibility, and 3D genome architecture. These results reveal the interplay between CG and non-CG methylation in heterochromatin maintenance and suggest that DNA methylation can directly impact chromatin structure.
Mechanistic basis of propofol-induced disruption of kinesin processivity
Authors: Dutta Mandira , Gilbert Susan P. , Onuchic José N. , Jana Biman
Published: January 2021

Significance

Kinesins are the major transporters of cargos toward the cell periphery, and their dysfunction leads to a range of human pathologies. Anesthetics used in surgery can shorten the distance that kinesins travel. We show that propofol binds at two crucial sites on the motor domain of the leading head, one at the microtubule interface and the other at the neck-linker region. In both cases, propofol disrupts the order–disorder transition of the neck linkers, resulting in loss of the signal for kinesin to step forward. In contrast, there was not an effect by propofol binding at the trailing head. These results provide a mechanism by which propofol disrupts kinesin stepping, which may diminish their ability to transport critical cargos.
Examining L1 influence in L2 word recognition
Authors: Jiang Nan
Published: January 2021

The present study examined L1 influence in visual L2 word recognition in the area of letter case. Whether an English word
is displayed in upper- or lower-case letters may be of little significance to English native speakers, but many ESL speakers from east Asia
have found it more difficult to recognize words printed in upper-case letters. Two experiments were conducted to explore two questions: (a)
whether there was indeed a case effect in L2 word recognition in that ESL speakers took longer in responding to upper-case words, and (b)
whether this case effect only occurred for ESL speakers whose first languages employed a script other than the Roman alphabet. The
participants included English native speakers, ESL speakers whose L1s employed the Roman alphabet (the Romance ESL group) and ESL speakers
whose L1s did not. They were asked to perform a lexical decision task on English words displayed in either upper- or lower-case letters. In
both experiments, a reliable case effect was found for the latter ESL group only. This L1-related case effect raised both theoretical and
pedagogical issues to be explored in future research.
On nonce echo constructions expressing disapproval and annoyance
Authors: Sánchez Fajardo José A.
Published: January 2021

The aim of this paper is to explore and contrast the morphosyntactic and semantic features of two equivalent nonce echo constructions (NECs) expressing disapproval and annoyance (i.e. don’t (you) X me and ni X ni Y) in colloquial English and Spanish. A NEC is defined as a reactive clause containing duplicated words of the initiative, showing the property of nonceness, and having a communicative goal. Two types of NECs are found in both languages: an attitudinal echo construction and a referential one, the former being more idiomatic than the latter. Based on the premise that texts are necessarily dialogic, two sets of examples are obtained from English corpora (The Movie Corpus, The TV Corpus, and the Corpus of American Soap Operas); and from two Spanish corpora and a dataset (CREA, CORPES XXI, and the Dataset of Spanish Dialogic Texts Online). Findings suggest that both languages show negative and restricted syntactic templates. Variables are coinages that originate from the processes of conversion in English (e.g. don’t you John me) and gender polarity in Spanish (e.g. ni luna ni *luno). Hence, although both types of variables are morphologically novel and contextually meaningful, Spanish variables are generally ungrammatical and unlikely to exist outside the discursive frame under study.
Good response to methotrexate is associated with a decrease in the gene expression of ABCG2, a drug transporter, in patients with rheumatoid arthritis
Authors: Muto Satoshi , Minamitani Nana , Ogura Takehisa , Nakajima Arata , Nakagawa Koichi , Masaka Toru , Hiura Sumiko , Kobayashi Hideki , Kato Hiroyoshi , Kameda Hideto
Published: January 2021

Objectives

Methotrexate (MTX) is used as an anchor drug in the treatment of rheumatoid arthritis (RA), although more than a half of the patients with RA require additional treatments. We designed a prospective study involving two medical centers in Japan to examine the association between the expression of MTX-related genes including a drug transporter ATP-binding cassette sub-family G member 2 (ABCG2) gene and the clinical response to MTX in MTX-naive patients with RA.

Methods

The primary endpoint of this study was good response based on the European League Against Rheumatism (EULAR) response criteria by Disease Activity Score using 28-joint count (DAS28). We evaluated the association between the baseline expression of six genes involved in the intracellular pharmacokinetics of MTX, including ABCG2, as well as their temporal changes, and the clinical response at week 12 from the initiation of MTX.

Results

Based on the clinical response at 12 weeks after the initiation of MTX, 24 patients were classified into good responders (n = 9) and non-good responders (n = 15; 10 moderate responders and 5 non-responders) groups. A univariate logistic regression analysis of the baseline gene expression levels to predict the EULAR good response at week 12 showed a significant association with ABCG2 expression alone. Furthermore, the rate of baseline expression of ABCG2 mRNA above the cut-off value determined using a receiver operating characteristic curve was higher in good responders than in non-good responders (p = .012). Moreover, ABCG2 expression decreased in almost all good responders, but not in non-good responders, after MTX treatment for 12 weeks (median −76% vs. +41% from baseline, respectively; p = .011). The ABCG2 expression level did not correlate with DAS28 at baseline or week 12.

Conclusions

Our study revealed that good response to MTX is associated with a decrease in the expression of ABCG2 in patients with RA.
Sodium bicarbonate supplementation and the female athlete: A brief commentary with small scale systematic review and meta‐analysis
Authors: Saunders Bryan , de Oliveira Luana Farias , Dolan Eimear , Durkalec‐Michalski Krzysztof , McNaughton Lars , Artioli Guilherme Giannini , Swinton Paul Alan
Published: January 2021

Sodium bicarbonate (SB) is considered an effective ergogenic supplement for improving high‐intensity exercise capacity and performance, although recent data suggests that women may be less amenable to its ergogenic effects than men. Currently, an apparent paucity of data on women means no consensus exists on whether women benefit from SB supplementation. The aim of the current study was to quantify the proportion of the published literature on SB supplementation that includes women, and to synthesise the evidence regarding its effects on blood bicarbonate and exercise performance in women by performing a systematic review and meta‐analysis. Electronic searches of the literature were undertaken using three databases (MEDLINE, Embase, SPORTDiscus) to identify relevant articles. All meta‐analyses were performed within a Bayesian framework. A total of 149 SB articles were identified, 11 of which contained individual group data for women. Results indicated a pooled blood bicarbonate increase of 7.4 [95%CrI: 4.2–10.4 mmol·L−1] following supplementation and a pooled standardised exercise effect size of 0.37 [95%CrI: −0.06–0.92]. The SB literature is skewed, with only 20% (30 studies) of studies employing female participants, of which only 11 studies (7.4%) provided group analyses exclusively in women. Despite the small amount of available data, results are consistent in showing that SB supplementation in women leads to large changes in blood bicarbonate and that there is strong evidence for a positive ergogenic effect on exercise performance that is likely to be small to medium in magnitude.

Highlights

This study aimed to quantify the proportion of the published literature on sodium bicarbonate supplementation that includes women and to synthesise the evidence regarding its ergogenic effect on women, using a systematic review and meta‐analytic approach.

The sodium bicarbonate literature is skewed, with only 30 studies (20%) employing female participants, of which only 11 studies (7.4%) provided group analyses exclusively in women.

Despite the small amount of available data, results are consistent in showing that sodium bicarbonate supplementation in women leads to large changes in blood bicarbonate and that there is strong evidence for a positive ergogenic effect on exercise performance that is likely small to medium in magnitude.

Based on these findings, we do not believe there is any evidence to support sex‐specific sodium bicarbonate dosing recommendations and that current recommendations of 0.2–0.3 g·kg−1BM of SB taken 60–180 min prior to high‐intensity exercise appear appropriate for the female athlete.
Arthrogenic muscle inhibition and return to sport after arthrofibrosis complicating anterior cruciate ligament surgery
Authors: Dauty Marc , Menu Pierre , Mesland Olivier , Fouasson‐Chailloux Alban
Published: January 2021

Arthrofibrosis is a devastating complication after Anterior Cruciate Ligament reconstruction (ACLr) characterized by a muscle weakness secondary to an arthrogenic muscle inhibition process. The loss of knee isokinetic strength due to arthrogenic muscle inhibition may be more important after arthrofibrosis, compared to an ACLr population with no complication. The isokinetic strength deficit [Limb Symmetry Index (LSI) at 60 and 180°/s of angular speed] was measured at 4, 7 and 12 post‐operative months. Knee function, return to running and return to sport were evaluated. A comparison of the Quadriceps and the Hamstring LSI between patients with arthrofibrosis and those without post‐operative complication was performed according to time and taking into consideration the type of surgical procedure. 539 primary ACLr patients were assessed. The arthrofibrosis group presented at 4, 7 and 12 post‐operative months a Quadriceps LSI significantly lower compared to the control group, without influence of the graft procedure (LSI: 38, 53, 68% vs 63, 73, 85% at 60°/s, respectively). The Hamstring LSI was significantly lower at 4 and 7 post‐operative months, but comparable at 12 months with an influence of the Hamstring procedure. Knee function was significantly lower at 4 and 7 post‐operative months. Few arthrofibrosis ACLr patients returned to running at 7 post‐operative months (6.8% vs 69.9%; p < .0001). An important and durable Quadriceps muscle weakness occurred after arthrofibrosis, whatever the type of graft procedure. This is explained by an Arthrogenic muscle inhibition which compromised the return to sport at the same level until 12 post‐operative months.

Highlights

An important and durable quadriceps muscle weakness occurred after arthrofibrosis.

The arthrogenic muscle inhibition was significant on the operated side independently of the type of the graft procedure.

Arthrogenic muscle inhibition compromised the return to sport at the same level until 12 post‐operative months.
Einstein’s time dilation and the relativistic Doppler shift: avoiding the pitfalls
Authors: Ataman S
Published: January 2021

Introductory textbooks for the theory of special relativity discuss the time dilation effect after introducing the Lorentz transformations. Reading the dictum ‘moving clocks run slow’ a student is likely to have the impression that this is a measured effect. On the other hand, after considering the relativistic Doppler effect the same student might be puzzled that this effect depends on the relative emitter-observer direction, contrary to Einstein’s time dilation. Simple thought experiments are presented here where the inferred time dilation and the observed relativistic Doppler effect give quite opposite answers. Before solving the puzzle, we show how easily one can get confused and obtain apparently contradictory results.
Numerical analysis of nitrogen fixation by nanosecond pulse plasma
Authors: Cheng He , Li Yiqian , Zheng Kuanlei , Liu Dawei , Lu Xinpei
Published: January 2021

Nonthermal plasma (NTP) provides a novel approach to developing renewable and efficient nitrogen fixation (NF) technology. However, the efficiency optimization of NTP-assisted NF (NTP-NF) remains challenging due to the elusive ultra-fast plasma process, especially in packed-bed dielectric barrier discharge (PB-DBD). Our work presents a unique view on how to optimize the efficiency of NTP-NF based on precise studies of plasma dynamics and chemistry by developing a novel nanosecond pulse driving PB-DBD model. 2D plasma dynamics show that the plasma propagates in the form of surface ionization waves coupled with filamentary micro-discharge. Electron heating by high instantaneously applied power determines the development of ionization waves and NO production. Plasma chemistry shows that selectively enhancing the energy of electronically excited dissociation to produce N* is the most efficient way to increase the production of NO.