bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutations Accounting for Congenital Fibrinogen Disorders: An Update
Authors: Richard Maxime , Celeny David , Neerman-Arbez Marguerite
Published: January 2022

Fibrinogen is a complex protein that plays a key role in the blood clotting process. It is a hexamer composed of two copies of three distinct chains: Aα, Bβ, and γ encoded by three genes, FGA, FGB, and FGG, clustered on the long arm of chromosome 4. Congenital fibrinogen disorders (CFDs) are divided into qualitative deficiencies (dysfibrinogenemia, hypodysfibrinogenemia) in which the mutant fibrinogen molecule is present in the circulation and quantitative deficiencies (afibrinogenemia, hypofibrinogenemia) with no mutant molecule present in the bloodstream. Phenotypic manifestations are variable, patients may be asymptomatic, or suffer from bleeding or thrombosis. Causative mutations can occur in any of the three fibrinogen genes and can affect one or both alleles. Given the large number of studies reporting on novel causative mutations for CFDs since the review on the same topic published in 2016, we performed an extensive search of the literature and list here 120 additional mutations described in both quantitative and qualitative disorders. The visualization of causative single nucleotide variations placed on the coding sequences of FGA, FGB, and FGG reveals important structure function insight for several domains of the fibrinogen molecule.
Arthroscopic Resection of a Large Osteochondroma of the Femoral Neck Overlying the Neurovascular Bundle: A Case Report
Authors: Krueger Van Schaumburg , Dove James Houston , Cohen Eric , Tabaddor Ramin
Published: January 2022

Only a few case reports have described the treatment of proximal femoral osteochondromas with excision using hip arthroscopy. We present the case of a 21-year-old male who presented with hip pain caused by an osteochondroma about the right femoral neck. Imaging obtained revealed a lesion that measured 4.4 × 3.2 × 5 cm abutting the neurovascular bundle along its anterior margin. After failed conservative measures, the patient underwent successful arthroscopic resection using two portals. This is the first case report presenting an arthroscopic resection of an osteochondroma located about the femoral neck adjacent to the neurovascular bundle.
The Influence of Flow Velocity in the Feeding Vessel on Flap Perfusion in Deep Inferior Epigastric Artery Perforator Flap
Authors: Cho Jeongmok , Han Hyun Ho , Eom Jin Sup
Published: January 2022

Background Contralateral perfusion of zones II and IV is critical to estimate the amount of fat necrosis and determine intraoperative flap sacrifice during autologous breast reconstruction. We aimed to determine whether perfusion of the contralateral side was affected by the peak flow velocity in the feeding vessels in the deep inferior epigastric artery (DIEA) perforator free flap reconstructions.

Methods This was a retrospective review of patients who received DIEA perforator flap for autologous breast reconstruction from February to July 2020. Intraoperative indocyanine green (ICG) angiography and measurement software (Image J) were used to validate the perfusion of the contralateral side of the flap. Peak flow in the vessels was measured with duplex color Doppler and linear correlation was used to analyze the association between perfusion and blood flow velocity.

Results Forty-two patients received a DIEP flap. The average age of the patients was 48.5 years, and body mass index was 23.84 kg/m2. Peak flow velocity of the internal mammary artery (IMA) was significantly higher than that of the DIEA (p <0.05). Contralateral perfusion confirmed by ICG angiography was higher in the IMA than in the DIEA (p <0.05). A linear correlation was found between peak speed (p = 0.045) and ICG perfusion length (p = 0.00003).

Conclusion The status of flap perfusion depends on the feeding vessel. The velocity of blood flow between IMA and DIEA is different, and the flap perfusion varies accordingly. Therefore, ICG angiography should be performed after anastomosis at the recipient site for an accurate assessment.
On the analyticity of electronic reduced densities for molecules
Authors: Jecko Thierry
Published: January 2022

We consider an electronic bound state of the usual, non-relativistic, molecular Hamiltonian with Coulomb interactions and fixed nuclei. Away from appropriate collisions, we prove the real analyticity of all the reduced densities and density matrices that are associated with this bound state. We provide a similar result for the associated reduced current density.
Applicability of coherent x-ray diffractive imaging to ferroelectric, ferromagnetic, and phase change materials
Authors: Shi Xiaowen , Shi Jian , Fohtung Edwin
Published: January 2022

Rapid development in the field of ferroelectric and magnetic materials has attracted much interest in the past decade. The underlying mechanisms of the fundamental phenomenon of phase transitions in these materials are extremely important in understanding their physical properties and their potential technological applications. Therefore, it is vital for the advancement of high-resolution versatile imaging techniques that enable high-throughput and nano-scale characterization in the nano-crystals and electronic devices. X-ray based imaging techniques such as Bragg coherent x-ray diffractive imaging (CXDI) has been one of the dominant nondestructive imaging tools with high-resolution and refraction sensitivities that provide quantitative information in bulk and nano-scale crystals and their associated nano-devices. In this review, we will focus on the recent developments of using Bragg CXDI at the state-of-art endstations in synchrotron radiation facilities worldwide to understand the structures of ferroelectric and magnetic materials and the structural phase transition of complex materials. We will also present our perspectives on the opportunities and challenges in using Bragg CXDI techniques for materials characterization.
Numerical analysis of the effects of distributed series resistance and lateral conduction in solar cells
Authors: Guo Hongliang , Sun Qiang , Zhang Qiming , Zhang Heng , Yao Liyong , Xue Chao , Wu Yanmei , Tang Yue , Liu Rubin
Published: January 2022

Large-area solar cells are more susceptible to imperfect surfaces, such as edges or cracks. Numerical two-dimensional methods are developed and applied to study the effects of the imperfect surface in solar cells. The two-dimensional effects investigated in this work reveal the lateral conduction of solar cells, which causes inconsistent potentials and a deviation of photocurrent. The mask effects from distributed series resistance on luminescence techniques, such as photoluminescence and electroluminescence, are also explored. Lateral conduction hides the information of the real distribution of defects, and numerical methods are applied to eliminate the effect. In multijunction solar cells, lateral conduction in the interlayer leads to the complementarity between the luminescence of top and bottom cells. Furthermore, the distributed series resistance also causes a knee in the I–V curves, resulting in a decrease in the efficiency of the cell. The research in this work demonstrates that different categories of defects show different influences on solar cells, and the effect is more obvious on the open-circuit voltage rather than the short-circuit current. The study of distributed series resistance and lateral conduction in this work not only gives an explanation of experimental data but also provides instructions for the developments of large-area solar cells.
Single photon randomness originating from the symmetric dipole emission pattern of quantum emitters
Authors: Hoese Michael , Koch Michael K. , Breuning Felix , Lettner Niklas , Fehler Konstantin G. , Kubanek Alexander
Published: January 2022

Quantum random number generation is a key ingredient for quantum cryptography and fundamental quantum optics and could advance Monte Carlo simulations and machine learning. An established generation scheme is based on single photons impinging on a beam splitter. Here, we experimentally demonstrate quantum random number generation solely based on the symmetric emission profile of a dipole aligned orthogonal to the laboratory frame. The demonstration builds on defect centers in hexagonal boron nitride that emit photons in random directions within the dipole emission profile and benefits from the ability to manipulate and align the emission directionality. We prove the randomness in correlated photon detection events making use of the NIST randomness test suite and show that the randomness remains for two independently emitting defect centers. The scheme can be extended to random number generation by coherent single photons with potential applications in solid-state based quantum communication at room temperature.
Ab initio study of ultrafast spin dynamics in Gdx(FeCo)1−x alloys
Authors: Dewhurst J. K. , Shallcross S. , Radu I. , Elliott P. , Korff Schmising C. v. , Sharma S.
Published: January 2022

Using an ultrashort laser pulse, we explore ab initio the spin dynamics of Gdx(FeCo)1−x at femtosecond time scales. Optical excitations are found to drive charges from Fe majority d-states to unoccupied Gd f-minority states with f-electron character excited occupation lagging behind that of the d-electron character, leading to substantial demagnetization of both species while leaving the global moment almost unchanged. For x > 0.33, this results in the creation of an ultrafast ferromagnetic (FM) transient by the end of the laser pulse with the Gd demagnetization rate slower than that of Fe. For all concentrations, the Gd moments begin to rotate from their ground state orientations developing in-plane moments of between 0.2 and 0.5 μB. Thus, the ultrafast spin dynamics of the material captures three important ingredients of all optical switching that occurs at much later (picosecond) times: (i) the development of a FM transient, (ii) the different rates of demagnetization of Fe and Gd, and (iii) the breaking of the collinear symmetry of the ground state. Furthermore, several predictions are made about the behavior of Fe–Gd alloys that can be experimentally tested and can lead to a spin-filtering device.
Nonlinear collision shifts of the 0–0 hyperfine transition due to van der Waals molecule formation
Authors: Camparo James
Published: January 2022

We consider the origin of nonlinear collision shifts for the 0–0 hyperfine transition in alkali/noble-gas systems due to van der Waals molecule formation. Developing a semi-empirical model, we describe the shift as arising from three fundamental interactions: (1) a fractional change in the alkali’s valence electron density at the alkali nucleus, η, which affects the hyperfine contact term; (2) a mixing of p-wavefunction character into the alkali ground state (characterized by the probability for p-state character appearing in the perturbed wavefunction ξ12), which gives rise to an electric quadrupole term in the ground-state hyperfine splitting; and (3) an interaction of the alkali’s valence electron with the magnetic field produced by molecular rotation, characterized by a magnetic field strength BvdW. In addition to these molecular parameters, the model also depends on the formation rate of van der Waals molecules, kfP2, and the breakup rate of the molecules, kbP, where P is the noble-gas pressure. Fitting the model to the 85Rb/Xe and 87Rb/Xe experimental data of McGuyer and co-workers (and taking previously measured values for kf and BvdW), we find that η = 9 × 10−3, ξ12 = 5 × 10−3, and kb = 2.9×107 s−1/Torr.
Phonons of metallic hydrogen with quantum Monte Carlo
Authors: Ly Kevin K. , Ceperley David M.
Published: January 2022

We describe a simple scheme to perform phonon calculations with quantum Monte Carlo (QMC) methods and demonstrate it on metallic hydrogen. Because of the energy and length scales of metallic hydrogen and the statistical noise inherent to QMC methods, the conventional manner of calculating force constants is prohibitively expensive. We show that our alternate approach is nearly 100 times more efficient in resolving the force constants needed to calculate the phonon spectrum in the harmonic approximation. This requires only the calculation of atomic forces, as in the conventional approach, and otherwise little or no programmatic modification.
Room-temperature magnetoresistive and magnetocaloric effect in La1−xBaxMnO3 compounds: Role of Griffiths phase with ferromagnetic metal cluster above Curie temperature
Authors: Zhang Hui , Wang Yan , Wang Haiou , Huo Dexuan , Tan Weishi
Published: January 2022

The evolution of the Griffiths phase (GP) with a ferromagnetic metal (FMM) cluster above the Curie temperature (TC) and its effect on the magnetic properties, electrical transport, magnetoresistance (MR), and magnetocaloric effect (MCE) is studied comprehensively, using bulk compounds of La1−xBaxMnO3 (0.15 ≤ x ≤ 0.25) with different lattice distortions but with the same structural symmetry and space group. These La1−xBaxMnO3 samples show ferromagnetic transition at TC increasing from 229 K for x = 0.15–300 K for x = 0.25, in addition to the presence of GP with FMM clusters in the paramagnetic (PM) region, which have been confirmed by the combination of magnetization (susceptibility) measurements, the GP theory, and electron paramagnetic resonance technology. With increasing the Ba2+ ion doping, GP temperature (TG) and TC of La1−xBaxMnO3 are increased, and the GP regime is strengthened. The GP ratio in the PM region reached 27.7% for the sample with x = 0.20. The resistivity decreases and the FMM phase increases with increasing x from 0.15 to 0.25, which can be explained by the decrease in the bandgap (Eg) and the enhancement of the double-exchange effect. Remarkably, large room-temperature MR (∼44.7%) can be observed in the sample with x = 0.25 under 60 kOe, which is related to the presence of the GP regime. Furthermore, the MCE is also affected by the GP regime, and it is deduced that the magnetic transition is of second order. The value of magnetic entropy change (|ΔSM|) reaches 3.04 J/kg  K near room temperature for the sample with x = 0.25 under 50 kOe. This value is associated with a relative cooling power (RCP) of 248.1 J/kg. For the sample with x = 0.15, the value of RCP reaches 307.6 J/kg under 50 kOe. The discovery of the MR and MCE near room temperature is of great significance from the practical application of perovskite manganites in magnetic sensors and magnetic refrigerants.
Hot-carrier infrared detection in PbS with ultrafast and highly sensitive responses
Authors: Wu Shiteng , Qin Liyun , Li Qinliang , Wu Ziyu , Nie Zhongquan , Jiang Yiqi , Wang Jianyu , Wang Zhendong , Zhou Yangbo , Yu Kuai , Wang Li , Wang Qisheng
Published: January 2022

Traditional infrared semiconductors with direct narrow bandgaps, such as HgCdTe, InGaAs, and lead salts (PbS, PbSe, and PbTe), have been commercialized for decades in various infrared technologies, such as night vision, military communication, and health monitoring. However, traditional infrared (specifically middle- and long-wave infrared) semiconductors suffer from serious noise generation via thermal excitation and external current bias. Although thermal infrared detectors can operate at room temperature, their response speed is very slow, typically on the order of milliseconds or worse, which limits their applications. Herein, we reinvent a classical lead salt semiconductor (PbS) as a room temperature, high speed, and high-detectivity infrared detector. The detection is operated via the self-driven (no bias voltage necessary) photothermoelectric (PTE) effect with a response time reaching 500 ns (limited by the measurement setup)—three orders of magnitude faster than commercial PTE and photoconductive PbS detectors. Furthermore, the physical principle of hot-carrier-dominated heat energy conversion is proposed to understand the unconventional ultrafast response behavior. Combined with high sensitivity at room temperature (noise equivalent power 0.3 pW Hz−1/2) and broadband detection range (0.4–2.3 μm), this hot carrier makes the traditional commercial semiconductor PbS applicable to a class of infrared detection applications.
Cross-relaxation interactions in ZnO:Mn2+: The ground state optical pumping
Authors: Azamat D. V. , Badalyan A. G. , Romanov N. G. , Hrabovsky M. , Jastrabik L. , Dejneka A. , Yakovlev D. R. , Bayer M.
Published: January 2022

A steady-state population inversion in the ground state of Mn2+ in ZnO was detected by application of continuous microwave and circularly polarized optical pumping in the temperature range of 3–6 K. Multiple spin-flip processes occur in view of a simultaneous saturation in the harmonically related transitions of Mn2+ spins. It is found that an additional relaxation channel arises at 2.7 K due to dynamic polarization of the 55Mn nuclei through the saturation of the first order electron-nuclear forbidden transitions. The transient populations are created between 55Mn nuclear sublevels.
Demonstration of ultra-small 5 × 5 μm2 607 nm InGaN amber micro-light-emitting diodes with an external quantum efficiency over 2%
Authors: Li Panpan , Li Hongjian , Yang Yunxuan , Zhang Haojun , Shapturenka Pavel , Wong Matthew , Lynsky Cheyenne , Iza Mike , Gordon Michael J. , Speck James S. , Nakamura Shuji , DenBaars Steven P.
Published: January 2022

Red micro-size light-emitting diodes (μLEDs) less than 10 × 10 μm2 are crucial for augmented reality (AR) and virtual reality (VR) applications. However, they remain very challenging since the common AlInGaP red μLEDs with such small size suffer from a dramatic reduction in the external quantum efficiency. In this work, we demonstrate ultra-small 5 × 5 μm2 607 nm amber μLEDs using InGaN materials, which show an EQE over 2% and an ultra-low reverse current of 10−9 A at −5 V. This demonstration suggests promising results of ultra-small InGaN μLEDs for AR and VR displays.
Random matrix description of dynamically backscattered coherent waves propagating in a wide-field-illuminated random medium
Authors: Miao Peng , Zhang Yifan , Wang Cheng , Tong Shanbao
Published: January 2022

The wave propagation in a random medium plays a critical role in optics and quantum physics. Multiple scattering of a coherent wave in a random medium determines the transport procedure. Brownian motions of scatterers perturb each propagation trajectory and form dynamic speckle patterns in the backscattered direction. In this study, we applied the random matrix theory to investigate the eigenvalue density of the backscattered intensity matrix. We find that the dynamic speckle patterns can be utilized to decouple the single and multiple backscattered components. The Wishart random matrix of the multiple scattering component is well described by the Marčenko–Pastur law, while the single scattering part has a low-rank characteristic. We, therefore, propose a strategy for estimating the first and second order moments of single and multiple scattering components, respectively, based on the Marčenko–Pastur law and trace analysis. Electric field Monte Carlo simulation and in vivo experiments demonstrate its potential applications in hidden absorbing object detection and blood flow imaging. Our method can be applied to other coherent domain elastic scattering phenomena for wide-field propagation of microwave, ultrasound, etc.
Structural design and optimization of a turning tool embedded with thin-film strain sensors for in-process cutting force measurement
Authors: Cheng Yunping , Wu Wenge , Liu Lijuan , He Zhenyu , Song Ding
Published: January 2022

A tool system integrated with machining and measurement is constructed by using thin film strain sensors and tool integration technology, which provides a new research method for studying the machining mechanism and automatic monitoring of the machining process. In this paper, three kinds—elastic sleeve type, fast insert type, and insert type—of tool cutting force measurement systems of the turning tool embedded with thin-film micro-sensors are designed. High strain sensitivity can be obtained through setting the elastic region of the tool bar on the premise of meeting the tool strength and stiffness. The system can realize integration between the thin-film strain sensor and tool bar quickly and efficiently. It is simplified as a cantilever beam structure for analysis after setting the shape of the sensor elastic substrate as a rectangle. The expression between strain and deflection of the elastic substrate is established when the free end is subjected to tangential force and bending moment, and the influence of the substrate’s structural parameters on the deflection is analyzed. In order to further improve the strain effect, six kinds of other shapes of the substrate structure are optimized, deducing the expression between the structure parameters and deflection; the corresponding substrate structure atlas is established, comparing and analyzing the deflection of the rectangular structure substrate. Five kinds of metal substrate materials are selected. In the functional film system of the thin-film strain sensor, the scheme of aluminum oxide and titanium nitride as the transition layer, silicon nitride as the insulating layer, and Ni–Cr alloy as the resistance grid layer is adopted. The research results show that this scheme can improve the adhesion between the insulating layer and the substrate, improve the resistance sensitivity coefficient of the sensor, and meet the application requirements of the cutting force measurement system.
Carbon emissions reductions from Indonesia’s moratorium on forest concessions are cost-effective yet contribute little to Paris pledges
Authors: Groom Ben , Palmer Charles , Sileci Lorenzo
Published: January 2022

Significance

More than a decade after the global adoption of REDD+ as a climate change mitigation strategy, countries have started accessing results-based payments. However, the extent to which payments are actually based on results is unknown, necessitating program evaluations to establish the contribution of REDD+ to the Paris NDCs. We undertake a microeconometric evaluation of one of the most globally significant REDD+ initiatives, Indonesia’s moratorium on forest concessions, in which a payment has been awarded. At the agreed US$5/tCO
2
-eq, the value of our estimated cumulative carbon emissions far exceeds the proposed payment from the donor, Norway. Although cost-effective, the emissions reductions only contribute 3 to 4% of Indonesia’s NDC. This contribution could be increased in new initiatives with better-designed incentives and institutional arrangements.
Myeloid cell TBK1 restricts inflammatory responses
Authors: Gao Tianxiao , Liu Ting , Ko Chun-Jung , Zhang Lingyun , Joo Donghyun , Xie Xiaoping , Zhu Lele , Li Yanchuan , Cheng Xuhong , Sun Shao-Cong
Published: January 2022

Significance

Macrophages play a crucial role in chronic inflammatory diseases, such as nonalcoholic steatohepatitis (NASH) and inflammatory bowel disease, but how the proinflammatory function of macrophages is controlled is not well understood. In this work, we identified TBK1 as a pivotal anti-inflammatory factor in macrophages that restricts inflammation in different disease models. Myeloid cell–specific TBK1 deficiency causes spontaneous development of metabolic disorders in aged mice and exacerbates high-fat diet–induced fatty liver disease with NASH-like symptoms. The
Tbk1
-MKO mice are also hypersensitive to experimental colitis. We obtained genetic evidence that TBK1 is crucial for controlling proinflammatory signaling pathway in macrophages. These findings establish TBK1 as a pivotal anti-inflammatory factor and a potential therapeutic target for the treatment of inflammatory diseases.
Molecular electronics sensors on a scalable semiconductor chip: A platform for single-molecule measurement of binding kinetics and enzyme activity
Authors: Fuller Carl W. , Padayatti Pius S. , Abderrahim Hadi , Adamiak Lisa , Alagar Nolan , Ananthapadmanabhan Nagaraj , Baek Jihye , Chinni Sarat , Choi Chulmin , Delaney Kevin J. , Dubielzig Rich , Frkanec Julie , Garcia Chris , Gardner Calvin , Gebhardt Daniel , Geiser Tim , Gutierrez Zachariah , Hall Drew A. , Hodges Andrew P. , Hou Guangyuan , Jain Sonal , Jones Teresa , Lobaton Raymond , Majzik Zsolt , Marte Allen , Mohan Prateek , Mola Paul , Mudondo Paul , Mullinix James , Nguyen Thuan , Ollinger Frederick , Orr Sarah , Ouyang Yuxuan , Pan Paul , Park Namseok , Porras David , Prabhu Keshav , Reese Cassandra , Ruel Travers , Sauerbrey Trevor , Sawyer Jaymie R. , Sinha Prem , Tu Jacky , Venkatesh A. G. , VijayKumar Sushmitha , Zheng Le , Jin Sungho , Tour James M. , Church George M. , Mola Paul W. , Merriman Barry
Published: January 2022

For nearly 50 years, the vision of using single molecules in circuits has been seen as providing the ultimate miniaturization of electronic chips. An advanced example of such a molecular electronics chip is presented here, with the important distinction that the molecular circuit elements play the role of general-purpose single-molecule sensors. The device consists of a semiconductor chip with a scalable array architecture. Each array element contains a synthetic molecular wire assembled to span nanoelectrodes in a current monitoring circuit. A central conjugation site is used to attach a single probe molecule that defines the target of the sensor. The chip digitizes the resulting picoamp-scale current-versus-time readout from each sensor element of the array at a rate of 1,000 frames per second. This provides detailed electrical signatures of the single-molecule interactions between the probe and targets present in a solution-phase test sample. This platform is used to measure the interaction kinetics of single molecules, without the use of labels, in a massively parallel fashion. To demonstrate broad applicability, examples are shown for probe molecule binding, including DNA oligos, aptamers, antibodies, and antigens, and the activity of enzymes relevant to diagnostics and sequencing, including a CRISPR/Cas enzyme binding a target DNA, and a DNA polymerase enzyme incorporating nucleotides as it copies a DNA template. All of these applications are accomplished with high sensitivity and resolution, on a manufacturable, scalable, all-electronic semiconductor chip device, thereby bringing the power of modern chips to these diverse areas of biosensing.
Direct observation of reversible liquid–liquid transition in a trehalose aqueous solution
Authors: Suzuki Yoshiharu
Published: January 2022

Significance

Recent studies on liquid water suggest that the two liquid waters exist in the supercooled temperature region and that their existence relates to the anomalous behavior of low-temperature liquid water such as the maximum density at 4 °C. However, the experimental investigation of two liquid waters is difficult because of the rapid crystallization. In this study, a reversible liquid–liquid transition in a trehalose aqueous solution by the change in pressure was observed directly. This result suggests strongly that two liquid waters exist in the aqueous solution. This study has implications for wide fields related to liquid water, such as solution chemistry, cryobiology, meteorology, and food engineering.
When danger strikes: A linguistic tool for tracking America’s collective response to threats
Authors: Choi Virginia K. , Shrestha Snehesh , Pan Xinyue , Gelfand Michele J.
Published: January 2022

Significance

People are constantly exposed to threatening language in mass communication channels, yet we lack tools to identify language about threats and track its impact on human groups. We developed a threat dictionary, a computationally derived linguistic tool that indexes threat levels from texts with high temporal resolution, across media platforms, and for different levels of analysis. The dictionary shows convergent validity with objective threats in American history, including violent conflicts, natural disasters, and pathogen outbreaks. Moreover, fluctuations in threat levels from the past 100 years coincide with America’s shifting cultural norms, political attitudes, and macroeconomic activity, demonstrating how this linguistic tool can be applied to understand the collective shifts associated with mass communicated threats.
No sustained increase in zooarchaeological evidence for carnivory after the appearance ofHomo erectus
Authors: Barr W. Andrew , Pobiner Briana , Rowan John , Du Andrew , Faith J. Tyler
Published: January 2022

Significance

Many quintessential human traits (e.g., larger brains) first appear inHomo erectus. The evolution of these traits is commonly linked to a major dietary shift involving increased consumption of animal tissues. Early archaeological sites preserving evidence of carnivory predate the appearance ofH. erectus, but larger, well-preserved sites only appear after the arrival ofH. erectus. This qualitative pattern is a key tenet of the “meat made us human” viewpoint, but data from sites across eastern Africa have not been quantitatively synthesized to test this hypothesis. Our analysis shows no sustained increase in the relative amount of evidence for carnivory after the appearance ofH. erectus, calling into question the primacy of carnivory in shaping its evolutionary history.
The impact of a poverty reduction intervention on infant brain activity
Authors: Troller-Renfree Sonya V. , Costanzo Molly A. , Duncan Greg J. , Magnuson Katherine , Gennetian Lisa A. , Yoshikawa Hirokazu , Halpern-Meekin Sarah , Fox Nathan A. , Noble Kimberly G.
Published: January 2022

Significance

This study demonstrates the causal impact of a poverty reduction intervention on early childhood brain activity. Data from the Baby’s First Years study, a randomized control trial, show that a predictable, monthly unconditional cash transfer given to low-income families may have a causal impact on infant brain activity. In the context of greater economic resources, children’s experiences changed, and their brain activity adapted to those experiences. The resultant brain activity patterns have been shown to be associated with the development of subsequent cognitive skills.
Disruption of MeCP2–TCF20 complex underlies distinct neurodevelopmental disorders
Authors: Zhou Jian , Hamdan Hamdan , Yalamanchili Hari Krishna , Pang Kaifang , Pohodich Amy E. , Lopez Joanna , Shao Yingyao , Oses-Prieto Juan A. , Li Lifang , Kim Wonho , Durham Mark A. , Bajikar Sameer S. , Palmer Donna J. , Ng Philip , Thompson Michelle L. , Bebin E. Martina , Müller Amelie J. , Kuechler Alma , Kampmeier Antje , Haack Tobias B. , Burlingame Alma L. , Liu Zhandong , Rasband Matthew N. , Zoghbi Huda Y.
Published: January 2022

Significance

Loss-of-function mutations in
MECP2
cause the neurological disorder Rett syndrome (RTT), but the precise molecular mechanism driving pathogenesis remains unclear. Using an unbiased approach to identify proteins that interact with MeCP2, we identified the transcription factor 20 (TCF20) complex and discovered that RTT-causing mutations in
MECP2
disrupt this interaction. Using biochemical, morphological, behavioral, and transcriptional studies, we examined the importance of this interaction for brain function and found that the TCF20 complex plays a direct role in MeCP2-dependent gene regulation and modifies
MECP2
-induced synaptic and behavioral deficits. Our data uncovered a previously unknown molecular aspect of MeCP2 function and revealed a converging molecular mechanism, whereby mutations of genes encoding several subunits in the same complex contribute to shared neurological symptoms.
Structures of the peptidase-containing ABC transporter PCAT1 under equilibrium and nonequilibrium conditions
Authors: Kieuvongngam Virapat , Chen Jue
Published: January 2022

Significance

Recent advances in cryo-electron microscopy (cryo-EM) enabled us to determine multiple structures from the same sample. At equilibrium, the Boltzmann distribution law can be applied to identify the lowest energy state of the protein. We found that the conformational distributions of PCAT1, the peptidase-containing ATP-binding cassette (ABC) transporter 1, are completely different in the presence and absence of the Mg
2+
ion. This difference reflects energy inflow from ATP hydrolysis, shifting the system out of equilibrium. The conformational distribution under ATP turnover condition is determined by the transition rates along the transport pathway rather than the energy of each state. This study demonstrates how cryo-EM data can be used to understand thermodynamic and kinetic properties of an active transporter.
Spin eigenmodes of skyrmion bags
Authors: Zeng Zhaozhuo , Song Chengkun , Wang Jianbo , Liu Qingfang
Published: January 2022

Recently, magnetic skyrmion bags have been numerically and experimentally discovered in a thick FeGe plate. Here, we systematically investigated the spin eigenmodes of skyrmion bags in a confined magnetic disk. A weak peak at lower frequency is found for the skyrmion bags with Q ≠ 0 rather than skyrmionium due to the reduced rotational symmetry. In addition, it is found that a lot of spin eigenmodes for skyrmion bags which are more complex than the breathing mode of ordinary skyrmion can also be excited due to the inner interaction between skyrmions. Afterward, the spin eigenmodes at different external fields as well as in different disk sizes are further investigated. The results reveal rich physical phenomena and help us understand the interactions between skyrmions well. In addition, it can also be used as a detection and characterization mechanism for skyrmion bags.
Analysis of the efficiency improvement of 273 nm AlGaN UV-C micro-LEDs
Authors: Qian Zeyuan , Zhu Shijie , Shan Xinyi , Yin Pan , Yuan Zexing , Qiu Pengjiang , Wang Zhou , Cui Xugao , Tian Pengfei
Published: January 2022

UV-C LEDs have great application prospects in the fields of sterilization, disinfection, and non-line-of-sight solar-blind communication. However, their efficiency is currently not high enough to satisfy these applications and needs to be improved. In this work, AlGaN based UV-C LEDs (273 nm) with size from 8 to 200 μm were fabricated to evaluate the size effect of external quantum efficiency (EQE). Higher EQE was detected in smaller-size UV-C micro-LEDs. Simulations on EQE were performed. The analysis on experimental data and the simulation results reveals that higher EQE originates from both higher internal quantum efficiency at high current densities due to better current spreading and higher light extraction efficiency (LEE) due to the larger proportion of sidewall. From the efficiency improvement mechanism, it is concluded that the most sever current density non-uniformity and LEE loss of UV-C devices compared with visible or near ultraviolet LEDs can be effectively restrained by preparing micro-LEDs. Our work helps to optimize the efficiency characteristics for UV-C applications.
Single-crystal growth and magnetic anisotropy in PrFe2Ga8
Authors: Wang Cuixiang , Wang Xingyu , Jia Ke , Wang Le , Yan Dayu , Feng Hai L , Li Shiliang , Shi Youguo
Published: January 2022

Single crystals of PrFe2Ga8 were successfully grown by using Ga self-flux. PrFe2Ga8 crystallizes in the CaCo2Al8-type orthorhombic structure with the space group Pbam (no. 55). By combining the results from the magnetic-susceptibility, specific-heat, and resistivity measurements, we show that PrFe2Ga8 exhibits a magnetic order at 14 K. For H // c, the antiferromagnetic order can be suppressed by magnetic fields. However, the magnetic order is robust against magnetic fields for H ⊥ c. Our results provide basic physical properties of PrFe2Ga8 and will help to further understand the magnetism in this system.
Estimation of population exposure to terrestrial gamma rays in Canada
Authors: Chen Jing , Ford Ken
Published: January 2022

Based on ground gamma ray spectrometry surveys conducted from 2007 to 2010 in populated areas across Canada (i.e. in southern Canada, excluding the northern territories), and with consideration of the exposure outdoors and indoors in various types of buildings as well as exposure to radionuclides in building materials (assuming most building materials are of local origin), the population-weighted annual effective dose from exposure to terrestrial gamma rays was estimated to be 167 ± 43 μSv. Under Canadian-specific average occupancy times, indoor exposures at home contribute 69% of the total annual effective dose, followed by 19% from indoor exposures other than at home, 6.2% from outdoor exposures and 5.8% from exposures inside vehicles. This assessment with measurements in a total of 1057 sites in populated areas across Canada is in general agreement with earlier assessments based on airborne gamma surveys mostly over unpopulated areas of Canada and truck-borne radiometric surveys along paved urban roads in four cities.
Plasma-based positron sources at EuPRAXIA
Authors: Sarri Gianluca , Calvin Luke , Streeter Matthew
Published: January 2022

Plasma-based positron sources are attracting significant attention from the research community, thanks to their rather unique characteristics, which include broad energy tuneability and ultra-short duration, obtainable in a compact and relatively inexpensive setup. Here, we show a detailed numerical study of the positron beam characteristics obtainable at the dedicated user target areas proposed for the EuPRAXIA facility, the first plasma-based particle accelerator to be built as a user facility for applications. It will be shown that MeV-scale positron beams with unique properties for industrial and material science applications can be produced, alongside with GeV-scale positron beams suitable for fundamental science and accelerator physics.
Propagation of dipole structure in an inhomogeneous-density plasma using two-dimensional particle-in-cell simulation
Authors: Hayashi Y , Das A , Habara H , Kaw P K , Tanaka K A
Published: January 2022

We have investigated the propagation of a magnetic dipole assuming a simple model of forward and return flow of fast electrons under a condition of plasma-density inhomogeneity by a particle-in-cell simulation. An exact propagating depiction of the dipolar structure is given under the framework of a simplified ‘electron magnetohydrodynamic’ fluid model (Yadav et al 2008 Phys. Plasmas
15 062308; Yadav et al 2009 Phys. Plasmas
16 040701; Yadav and Das 2010 Phys. Plasmas
17 052306) in a dense plasma. We reproduce this structure in our kinetic calculations. The results indicate that, with a steep plasma density gradient, the structure evolves rapidly toward plasma in a process involving shock formation and rapid dissipation of beam energy, which is consistent with the fluid simulations. In addition, new features are also reported, such as the pinching of the two dipole lobes to form a very strong shear layer, which develops into a Kelvin–Helmholtz instability. The magnetic energy is rapidly converted to kinetic energy of electrons leading to additional plasma heating in inhomogeneous regions, such as the core region in an imploded plasma.
Study of He + 0.2% O2 plasma jet impinging on liquid surface from He(23S1) metastable atoms density measurements
Authors: Invernizzi Laurent , Sadeghi Nader , Sainct Florent P , Guillot Philippe
Published: January 2022

This work presents spatial variations of the helium He(23S1) metastable atom absolute densities in a plasma jet at atmospheric pressure in He + 0.2% O2 gas mixture impinging on a liquid target. The plasma jet is ignited with 6 kV pulses of 2.5 μs duration and 8 ns rise and fall times at 20 kHz repetition rate. Streamers are created in both rising and falling fronts of the high voltage (HV). From Abel inversion of the line averaged absorbance of 1083 nm helium line, measured by laser absorption spectroscopy, the radial profiles of He(23S1) density along the plasma jet are deduced in two sources with different residence time of the gas within the discharge volume, having three different outlet tube diameters and with two gas flow rates. The metastable densities up to ∼3 × 1013 cm−3 have been measured. The radial profile remained always axially centered for the 1.5 mm outlet tube and with 0.5 slm for the larger diameter tubes. But in this later tubes and with 2 slm gas flow rate, the profile changed from a ring shape at the tube exit to axially centered when increasing the distance from the tube edge. In the rising front of the HV, the ring profile of He(23S1) density in the tube exit is attributed to the shape of the electric field, produced by the applied HV to the electrode wrapped around the dielectric tube. In the falling front of the HV, the electric field results from electrons deposited on the inner surface of the dielectric tube and positive ions accumulated on the surface of liquid during the 2.5 μs duration of the HV pulse. The influence of oxygen by-products formed in the plasma volume (O, O2(Δ), O3, positive and negative oxygen ions) on the dynamic of the plasma jet are analyzed.
Influence of geometry constraint in finite space on impact resistance of shear thickening fluid
Authors: Li Anqi , Yang Gang , Yao Chenhui , Yan Xue , Hu Dean
Published: January 2022

The shear thickening area formed by impact load and the restriction boundary conditions play an important role in the impact resistance and energy absorption characteristics of the shear thickening fluid (STF). In order to reveal the low speed impact resistance of STF under finite space constraints, this paper carried out research through the preparation of STF, viscosity test and design of low speed drop weight impact experiment. Firstly, STF samples with different mass fractions were prepared by self-made. Then, the rheological tests were implemented to obtain the characteristics of STF viscosity under different shear rate loads. Next, a straightforward test through rapidly pulling the glass rod out of the STF was adopted to observe the shear thickening mechanism of STF. After that, two kinds of STF samples with different mass fractions and good shear thickening performance were selected for low speed drop weight test. In the drop weight test, three containers with different geometries were designed to equivalent the finite space constraints to reveal the low speed impact resistance of STF under finite space constraints. Finally, combined with the experimental results, a series of numerical models are established to study the influence of geometric parameters in finite space on the impact resistance of STF. Through the research of this paper, the influence of geometry constraint in finite space on impact resistance of STF was obtained, which can provide reference for the geometric design of protective structure filled with STF.
Coaxial 3D printed anisotropic thermal conductive composite aerogel with aligned hierarchical porous carbon nanotubes and cellulose nanofibers
Authors: Wang Feng , Yang Zhijie , Hu Xiangzhou , Pan Yu , Lu Yuan , Jiang Man
Published: January 2022

Thermal management materials are obtaining increasing research interest, due to the requirement on energy conservation and environment protection. However, the complex designs and energy-consuming manufacturing processes prohibit their wide spread practical account. 3D printing is an intriguing revolutionary technology in fabricating anisotropic thermal conductive materials because of its inherent virtues on directional additive manufacturing a complicated subject with designed microstructure. We demonstrate the coaxial 3D printing along with directional freezing processes to obtain anisotropic thermal conductive composite aerogel consisting of carbon nanotubes (CNTs) and cellulose nanofibers (CNFs). The as prepared composite aerogel, with the thermal conductive CNTs as inner layer, and the insulate CNFs as outer layer, presented remarkable anisotropic thermal conductivity with 0.025 W (m K)−1 in the axial direction and 0.302 W (m K)−1 in the radial direction. The Young’s modulus of the CNTs/CNFs composite aerogel was tested to be 10.91 MPa in the axial direction, and 2.62 MPa in the radial direction, respectively. The coaxial 3D printed CNTs/CNFs composite aerogel has great potential application in electronics, especially for those custom-tailored products and the related field.
Design of novel piezoelectric energy harvester utilizing the force generated from human walking
Authors: Sirigireddy Pravallika , Eladi Paul Braineard
Published: January 2022

A novel piezoelectric energy harvester (z-PEH) to harness a significant amount of waste energy from human walking is proposed in the present work. The unique feature of the z-PEH is that a greater number of piezoelectric discs are planted in the z-direction without consuming a wide area of the pavement or road surface, hence termed z-PEH. This enables minimum damage to the existing pavements or roads during installation, maintenance and repair works. The power generating piezoelectric bimorphs are glued to aluminum plates attached to the hollow steel structure which is mounted on a spring. The z-PEH module consists of eight commercially available bimorphs, with each bimorph having two circular piezoelectric discs of diameter 25 mm and a thickness of 0.25 mm. The experimental and numerical open-circuit voltages of a single PZT are 9.38, 15.86 and 29.5 V and 9.23, 18.31 and 28.6 V respectively for applied weights of 24.5, 49 and 73.5 N. The z-PEH module occupied an area of 21.1 × 18 cm2. The numerical design is further carried out in commercially available software ANSYSTM with the objective of enhancing output power of the z-PEH module with in the same area. It is found out that, the optimized z-PEH module with square bimorphs, generated an open-circuit Peak-to-peak voltage of 69.07 V and the maximum DC power generated is 0.56 mW for an applied force of 73.5 N. Also, the z-PEH module with 56 bimorphs resulted in an average DC power of 3.95 mW for a step loading of 490 N (equal to 50 kg) under maximum power transfer conditions. The power density in this case is 2.49 W m−3.
Fast full N-body simulations of generic modified gravity: derivative coupling models
Authors: Hernández-Aguayo César , Ruan Cheng-Zong , Li Baojiu , Arnold Christian , Baugh Carlton M. , Klypin Anatoly , Prada Francisco
Published: January 2022

We present mg-glam, a code developed for the very fast production of full N-body cosmological simulations in modified gravity (MG) models. We describe the implementation, numerical tests and first results of a large suite of cosmological simulations for two broad classes of MG models with derivative coupling terms — the Vainshtein- and Kmouflage-type models — which respectively features the Vainshtein and Kmouflage screening mechanism. Derived from the parallel particle-mesh code glam, mg-glam incorporates an efficient multigrid relaxation technique to solve the characteristic nonlinear partial differential equations of these models. For Kmouflage, we have proposed a new algorithm for the relaxation solver, and run the first simulations of the model to understand its cosmological behaviour. In a companion paper, we describe versions of this code developed for conformally-coupled MG models, including several variants of f(R) gravity, the symmetron model and coupled quintessence. Altogether, mg-glam has so far implemented the prototypes for most MG models of interest, and is broad and versatile. The code is highly optimised, with a tremendous (over two orders of magnitude) speedup when comparing its running time with earlier N-body codes, while still giving accurate predictions of the matter power spectrum and dark matter halo abundance. mg-glam is ideal for the generation of large numbers of MG simulations that can be used in the construction of mock galaxy catalogues and accurate emulators for ongoing and future galaxy surveys.