Search

We examine the thermal origin of the detected "saw-tooth" shaped Hall resistance (R xy ) signals in the spin–orbit torque switching experiment for antiferromagnetic MnN. Compared with the results of the heavy metal/antiferromagnet bilayers (MnN/Ta), the qualitatively same "saw-tooth" shaped signals also appear in the samples with the heavy metal layer alone (either Ta or Pt) without the MnN layer. In addition, the R xy signal changes oppositely in the devices with Ta and Pt, due to the opposite temperature coefficient of resistivity of the two materials. All those results are consistent with the "localized Joule heating" mechanism in devices with Hall crosses geometry. Moreover, by utilizing a structure with separated writing current paths and Hall cross area, the quadratic relationship between Δ R xy and the writing current's amplitude is observed, which provides quantitative evidence of the thermal contribution. These results reveal the dominant thermal artifact in the widely used Hall crosses geometry for Néel vector probing and also provide a strategy to semi-quantitatively evaluate the thermal effect, which can shed light on a more conclusive experiment design. [ABSTRACT FROM AUTHOR]

The use of voltage induced strain to switch magnetic tunnel junctions (MTJs) is a promising solution for reducing the switching energy in MRAM technologies. The MTJ is integrated with a piezoelectric layer to generate the strain. A very thin layer is needed to switch with small voltages and small energy dissipation. It is challenging to synthesize ultrathin piezoelectric layers that retain a high degree of piezoelectricity. An alternate approach is to use time-varying strain generated by a surface acoustic wave (SAW). This approach does not require a thin piezoelectric layer since the SAW is confined to the surface of the layer. In this study, we fabricated in-plane MTJs on piezoelectric LiNbO3 substrates and used IDTs to generate the SAW signal within the substrate. Our results showed that the SAW signal had a significant influence on the resistance and the tunneling magnetoresistance (TMR) ratio of the MTJs. The influence was much less significant in nanometer size MTJs than in micrometer sized ones. Most surprisingly, the SAW signal caused the tunneling magnetoresistance ratio (TMR) to drop below zero for the micrometer size MTJ, meaning that the antiparallel resistance RAP is temporarily less than the parallel resistance RP under SAW excitation. Our results provide insight into the dynamic behavior of MTJs under periodic strain and the dependence of this behavior on the device dimensions as they are scaled down to nanometer sizes. [ABSTRACT FROM AUTHOR]

Recent advancement in the switching of perpendicular magnetic tunnel junctions with an electric field has been a milestone for realizing ultra-low energy memory and computing devices. To integrate with current spin-transfer torque-magnetic tunnel junction and spin–orbit torque-magnetic tunnel junction devices, the typical linear fJ/V m range voltage controlled magnetic anisotropy (VCMA) needs to be significantly enhanced with approaches that include new materials or stack engineering. A possible bidirectional and 1.1 pJ/V m VCMA effect has been predicted by using heavily electron-depleted Fe/MgO interfaces. To improve upon existing VCMA technology, we have proposed inserting high work function materials underneath the magnetic layer. This will deplete electrons from the magnetic layer biasing the gating window into the electron-depleted regime, where the pJ/V m and bidirectional VCMA effect was predicted. We have demonstrated tunable control of the Ta/Pd(x)/Ta underlayer's work function. By varying the Pd thickness (x) from 0 to 10 nm, we have observed a tunable change in the Ta layer's work function from 4.32 to 4.90 eV. To investigate the extent of the electron depletion as a function of the Pd thickness in the underlayer, we have performed DFT calculations on supercells of Ta/Pd(x)/Ta/CoFe/MgO, which demonstrate that electron depletion will not be fully screened at the CoFe/MgO interface. Gated pillar devices with Hall cross geometries were fabricated and tested to extract the anisotropy change as a function of applied gate voltage for samples with various Pd thicknesses. The electron-depleted Pd samples show three to six times VCMA improvement compared to the electron accumulated Ta control sample. [ABSTRACT FROM AUTHOR]

WTAP-VIRMA counteracts dsDNA binding of the m6A writer METTL3-METTL14 complex and maintains N6-adenosine methylation activity Therefore, the RGG of METTL14 helps METTL3-METTL14 bind to nucleic acids and supports the interaction between METTL3-METTL14 and WTAP-VIRMA. Upon addition of the unlabeled WTAP-VIRMA SP 381-1486 sp , ssRNA SB GGACU sb , ssRNA SB UUUUU sb , or dsDNA SB 50 sb to the SP 15 sp N-labeled RGG, a similar set of peaks were found to be perturbed, meaning that WTAP-VIRMA SP 381-1486 sp , dsDNA SB 50 sb , ssRNA SB GGACU sb , and ssRNA SB UUUUU sb interact with the RGG of METTL3-METTL14 via a similar interface, which may lead to their competitive binding to METTL3-METTL14. In METTL3-METTL14, two types of nucleic acid-binding domains were identified[2], including the zinc finger domain (ZFD) in METTL3 and the RGG motif (RGG) in METTL14. [Extracted from the article]

Summary: Bacillus thuringiensis (Bt)‐secreted crystal (Cry) toxins form oligomeric pores in host cell membranes and are a common element in generating insect‐resistant transgenic crops. Although Cry toxin function has been well documented, cellular defences against pore‐formation have not been as well developed. Elucidation of the processes underlying this defence, however, could contribute to the development of enhanced Bt crops. Here, we demonstrate that Cry1Ca‐mediated downregulation of microRNA‐7322‐5p (miR‐7322‐5p), which binds to the 3′ untranslated region of p38, negatively regulates the susceptibility of Chilo suppressalis to Cry1Ca. Moreover, Cry1Ca exposure enhanced phosphorylation of Hsp19, and hsp19 downregulation increased susceptibility to Cry1Ca. Further, Hsp19 phosphorylation occurs downstream of p38, and pull‐down assays confirmed the interactions between Hsp19 and Cry1Ca, suggesting that activation of Hsp19 by the miR‐7322‐5p/p38/Hsp19 pathway promotes Cry1Ca sequestration. To assess the efficacy of targeting this pathway in planta, double‐stranded RNA (dsRNA) targeting C. suppressalis p38 (dsp38) was introduced into a previously generated cry1Ca‐expressing rice line (1CH1‐2) to yield a single‐copy cry1Ca/dsp38 rice line (p38‐rice). Feeding on this rice line triggered a significant reduction in C. suppressalis p38 expression and the line was more resistant to C. suppressalis than 1CH1‐2 in both short term (7‐day) and continuous feeding bioassays as well as field trials. These findings provide new insights into invertebrate epithelium cellular defences and demonstrate a potential new pyramiding strategy for Bt crops. [ABSTRACT FROM AUTHOR]

Contrary to topological insulators, topological semimetals possess a nontrivial chiral anomaly that leads to negative magnetoresistance and are hosts to both conductive bulk states and topological surface states with intriguing transport properties for spintronics. Here, we fabricate highly-ordered metallic Pt3Sn and Pt3SnxFe1-x thin films via sputtering technology. Systematic angular dependence (both in-plane and out-of-plane) study of magnetoresistance presents surprisingly robust quadratic and linear negative longitudinal magnetoresistance features for Pt3Sn and Pt3SnxFe1-x, respectively. We attribute the anomalous negative longitudinal magnetoresistance to the type-II Dirac semimetal phase (pristine Pt3Sn) and/or the formation of tunable Weyl semimetal phases through symmetry breaking processes, such as magnetic-atom doping, as confirmed by first-principles calculations. Furthermore, Pt3Sn and Pt3SnxFe1-x show the promising performance for facilitating the development of advanced spin-orbit torque devices. These results extend our understanding of chiral anomaly of topological semimetals and can pave the way for exploring novel topological materials for spintronic devices. Negative longitudinal magnetoresistance refers to a decrease in resistance with the external magnetic field when the field direction is applied parallel to the current direction. It is considered an experimental signature of topological semimetals. Here, Zhang et al find clear and robust quadratic and linear negative longitudinal magnetoresistance in Pt3Sn and Pt3SnxFe1-x films. [ABSTRACT FROM AUTHOR]

The conformational change of METTL1 induced by WDR4 binding, especially in the vicinity of the SAM-binding pocket, indicated that WDR4 may affect the SAM-binding ability of METTL1. We further inspected the R170-interacting residues within the METTL1-WDR4 complex and found that R170 interacted extensively with other residues within the METTL1-WDR4 complex (Fig. First, METTL1 residues 107-112 (EIRVKV), which are important for SAM binding and recognition, formed an extended loop in the WDR4-bound state, instead of a short loop in apo or SAM-bound METTL1 (Fig. [Extracted from the article]

The Orbital Hall effect, which originates from materials with weak spin-orbit coupling, has attracted considerable interest for spin-orbitronic applications. Here, we demonstrate the inverse effect of the orbital Hall effect and observe orbitronic terahertz emission in the Ti and Mn materials. Through spin-orbit transition in the ferromagnetic layer, the generated orbital current can be converted to charge current in the Ti and Mn layers via the inverse orbital Hall effect. Furthermore, the inserted W layer provides an additional conversion of the orbital-charge current in the Ti and Mn layers, significantly enhancing the orbitronic terahertz emission. Moreover, the orbitronic terahertz emission can be manipulated by cooperating with the inverse orbital Hall effect and the inverse spin Hall effect in the different sample configurations. Our results not only discover the physical mechanism of condensed matter physics but also pave the way for designing promising spin-orbitronic devices and terahertz emitters. [ABSTRACT FROM AUTHOR]

The thermal blooming effect, platform jitter, and other effects of laser beam propagation cause serious deviation, which will have a negative impact on laser tracking systems. It is important to ensure that the laser beam does not deviate. Based on a fast steering mirror, a CMOS camera, and a Flex RIO system, a laser beam jitter control system is designed and implemented. The error is detected by camera and compensated for by the fast steering mirror (FSM), which is controlled by the Flex RIO device. By using LabVIEW and MATLAB, a closed loop model is realized. The results show that the system response is highly stabilized and has a short rise time, providing a reference for engineering applications. [ABSTRACT FROM AUTHOR]

Inorganic polyphosphate (polyP) is an ancient energy metabolite and phosphate store that occurs ubiquitously in all organisms. The vacuolar transporter chaperone (VTC) complex integrates cytosolic polyP synthesis from ATP and polyP membrane translocation into the vacuolar lumen. In yeast and in other eukaryotes, polyP synthesis is regulated by inositol pyrophosphate (PP-InsP) nutrient messengers, directly sensed by the VTC complex. Here, we report the cryo-electron microscopy structure of signal-activated VTC complex at 3.0 Å resolution. Baker's yeast VTC subunits Vtc1, Vtc3, and Vtc4 assemble into a 3:1:1 complex. Fifteen trans-membrane helices form a novel membrane channel enabling the transport of newly synthesized polyP into the vacuolar lumen. PP-InsP binding orients the catalytic polymerase domain at the entrance of the trans-membrane channel, both activating the enzyme and coupling polyP synthesis and membrane translocation. Together with biochemical and cellular studies, our work provides mechanistic insights into the biogenesis of an ancient energy metabolite. The VTC complex generate eukaryotic polyphosphate (polyP). Authors here reveal how the signal-activated VTC synthesize cytosolic polyP and transport polyP across vacuolar membrane into the lumen, by using cryo-EM, in-cell NMR, and smFRET analyses. [ABSTRACT FROM AUTHOR]

N6-methyldeoxyadenine (6mA) has recently been reported as a prevalent DNA modification in eukaryotes. The Tetrahymena thermophila MTA1 complex consisting of four subunits, namely MTA1, MTA9, p1, and p2, is the first identified eukaryotic 6mA methyltransferase (MTase) complex. Unlike the prokaryotic 6mA MTases which have been biochemically and structurally characterized, the operation mode of the MTA1 complex remains largely elusive. Here, we report the cryogenic electron microscopy structures of the quaternary MTA1 complex in S-adenosyl methionine (SAM)-bound (2.6 Å) and S-adenosyl homocysteine (SAH)-bound (2.8 Å) states. Using an AI-empowered integrative approach based on AlphaFold prediction and chemical cross-linking mass spectrometry, we further modeled a near-complete structure of the quaternary complex. Coupled with biochemical characterization, we revealed that MTA1 serves as the catalytic core, MTA1, MTA9, and p1 likely accommodate the substrate DNA, and p2 may facilitate the stabilization of MTA1. These results together offer insights into the molecular mechanism underpinning methylation by the MTA1 complex and the potential diversification of MTases for N6-adenine methylation. [ABSTRACT FROM AUTHOR]

Anesthetic-induced loss of consciousness (LOC) has been studied using functional connectivity (FC) and functional network analysis (FNA), manifested as fragmentation of the whole-brain functional network. However, how the fragmented brain networks reversibly recover during the recovery of consciousness (ROC) remains vague. This study aims to investigate the changes in brain network structure during ROC, to better understand the network fragmentation during anesthesia, thus providing insights into consciousness monitoring. We analyzed EEG data recorded from 15 individuals anesthetized by sevoflurane. By investigating the properties of functional networks generated using different brain atlases and performing community detection for functional networks, we explored the changes in brain network structure to understand how fragmented brain networks recover during the ROC. We observed an overall larger FC magnitude during LOC than in the conscious state. The ROC was accompanied by the increasing binary network efficiency, decreasing FC magnitude, and decreasing community similarity with the functional atlas. Furthermore, we observed a negative correlation between modularity and community number ($\text{p} < 0.001$ and $\textit {BF}_{{10}} >4000$ , linear regression test), in which modularity increased and community number decreased during ROC. Our results show that a larger FC magnitude reveals excessive synchronization of neuronal activities during LOC. The increasing binary network efficiency, decreasing community number, and decreasing community similarity indicate the recovery of functional network integration. The increasing modularity implies the recovery of functional network segregation during ROC. The results suggest the limitation of FC magnitude and modularity in monitoring anesthetized states and the potential of integrated information theory to evaluate consciousness. [ABSTRACT FROM AUTHOR]

Various kinds of cap structures, such as m7G, triphosphate groups, NAD and dpCoA, protect the 5′ terminus of RNA. The cap structures bond covalently to RNA and affect its stability, translation, and transport. The removal of the caps is mainly executed by Nudix hydrolase family proteins, including Dcp2, RppH and NudC. Numerous efforts have been made to elucidate the mechanism underlying the removal of m7G, triphosphate group, and NAD caps. In contrast, few studies related to the cleavage of the RNA dpCoA cap have been conducted. Here, we report the hydrolytic activity of Escherichia coli NudC towards dpCoA and dpCoA-capped RNA in vitro. We also determined the crystal structure of dimeric NudC in complex with dpCoA at 2.0 Å resolution. Structural analysis revealed that dpCoA is recognized and hydrolysed in a manner similar to NAD. In addition, NudC may also remove other dinucleotide derivative caps of RNA, which comprise the AMP moieties. NudC homologs in Saccharomyces cerevisiae and Arabidopsis thaliana exhibited similar dpCoA decapping (deCoAping) activity. These results together indicate a conserved mechanism underpinning the hydrolysis of dpCoA-capped RNA in both prokaryotes and eukaryotes. [ABSTRACT FROM AUTHOR]

Spintronic devices, especially electric‐field and spin–orbit torque driven magnetic tunnel junctions (MTJs), are promising candidates to replace the current memory and logic components for satisfying future computing demands. Current spin–orbit torque based MTJ devices with a single free layer and spin Hall channel still face high current density for switching. Here, 150‐nm perpendicular MTJs are designed and fabricated with a synthetic‐antiferromagnetic free layer and a bilayered spin Hall channel. The switching behavior is investigated via combination of forces from electric‐field and spin–orbit torque, where the electric field can modulate the exchange coupling of the synthetic‐antiferromagnetic free layer. Through an assistance of spin–orbit torque, bidirectional switching is obtained with switching current density as low as 3 × 103 A cm−2, which is two orders of magnitude lower than that of the current best reported values. These results suggest that electric‐field switching of synthetic‐antiferromagnetic MTJs could be a promising approach for reducing write current density of spintronic devices. [ABSTRACT FROM AUTHOR]

Unidirectional spin Hall magnetoresistance (USMR) is a magnetoresistance effect with potential applications to read two-terminal spin–orbit-torque (SOT) devices directly. In this work, we observed a large USMR value (up to 0.7 × 10−11 per A/cm2, 50% larger than reported values from heavy metals) in sputtered amorphous PtSn4/CoFeB bilayers. Ta/CoFeB bilayers with interfacial MgO insertion layers are deposited as control samples. The control experiments show that increasing the interfacial resistance can increase the USMR value, which is the case in PtSn4/CoFeB bilayers. The observation of a large USMR value in an amorphous spin–orbit-torque material has provided an alternative pathway for USMR application in two-terminal SOT devices. [ABSTRACT FROM AUTHOR]

Genetically modified plants with insecticidal proteins from Bacillus thuringiensis (Bt) have been successfully utilized to control various kinds of pests in crop production and reduce the abuse of pesticides. However, a limited number of genes are available for the protection of crops from rice planthopper. Recently, Cry78Aa protein from Bt strain C9F1 has been found to have high insecticidal activity against Laodelphax striatellus and Nilaparvata lugens. It is the first reported single-component protein in the world to combat rice planthoppers, making it very promising for use in transgenic crops. The ambiguous mechanism of Cry78Aa functions prevented further engineering or application. Here, we report the crystal structure of Cry78Aa, which consists of two domains: a C-terminal β-pore forming domain belonging to the aerolysin family and an N-terminal trefoil domain resembling the S-type ricin B lectin. Thus, Cry78Aa could represent a distinctive type of β-pore forming toxin. We also found that Cry78Aa binds carbohydrates such as galactose derivatives and is essential for insecticidal activity against Laodelphax striatellus. Our results suggest a mechanism underlying the function of Cry78Aa against rice planthoppers and pave the way to maximizing the usage of the toxin. The crystal structure of the Bacillus thuringiensis protein Cry78Aa shows it consists of a C-terminal β-pore forming domain and an N-terminal trefoil domain and suggests a mechanism underlying the function of Cry78Aa against rice planthoppers. [ABSTRACT FROM AUTHOR]

Carbonaceous materials are considered strong candidates as anode materials for sodium‐ion batteries (SIBs), which are expected to play an indispensable role in the carbon‐neutral era. Herein, novel braided porous carbon fibres (BPCFs) are prepared using the chemical vapour deposition (CVD) method. The BPCFs possess interwoven porous structures and abundant vacancies. The growth mechanism of the BPCFs can be attributed to the polycrystalline transformation of the nanoporous copper catalyst in the early stage of CVD process. Density functional theory calculations suggest that the Na+ adsorption energies of the mono‐vacancy edges of the BPCFs (−1.22 and −1.09 eV) are lower than that of an ideal graphene layer (−0.68 eV), clarifying in detail the adsorption‐dominated sodium storage mechanism. Hence, the BPCFs as an anode material present an outstanding discharge capacity of 401 mAh g−1 at 0.1 A g−1 after 500 cycles. Remarkably, this BPCFs anode, under high‐mass‐loading of 5 mg cm−2, shows excellent long‐term cycling ability with a reversible capacity of 201 mAh g−1 at 10 A g−1 over 1000 cycles. This study provided a novel strategy for the development of high‐performance carbonaceous materials for SIBs. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease. Misfolded Cu, Zn-superoxide dismutase (SOD1) has been linked to both familial and sporadic ALS. SOD1 fibrils formed in vitro share toxic properties with ALS inclusions. Here we produced cytotoxic amyloid fibrils from full-length apo human SOD1 under reducing conditions and determined the atomic structure using cryo-EM. The SOD1 fibril consists of a single protofilament with a left-handed helix. The fibril core exhibits a serpentine fold comprising N-terminal segment (residues 3–55) and C-terminal segment (residues 86–153) with an intrinsic disordered segment. The two segments are zipped up by three salt bridge pairs. By comparison with the structure of apo SOD1 dimer, we propose that eight β-strands (to form a β-barrel) and one α-helix in the subunit of apo SOD1 convert into thirteen β-strands stabilized by five hydrophobic cavities in the SOD1 fibril. Our data provide insights into how SOD1 converts between structurally and functionally distinct states. Misfolded SOD1 has been linked to both familial and sporadic ALS. Here the authors have determined the cryo-EM structure of SOD1 fibrils, providing insights into the conversion of SOD1 from its immature form into an aggregated form during pathogenesis of ALS. [ABSTRACT FROM AUTHOR]

Interlayer exchange coupling in polycrystalline Co2FeAl/Cr/Co2FeAl multilayers with Ta and MgO capping layers is investigated. Compared with Ta‐capped samples, the MgO capping layer induces the oscillatory coupling periods, ≈2.1 nm for Si substrate and ≈4.0 and ≈1.9 nm for SiO2 substrate. The oscillatory coupling period originates from the formation of quantum well states at the Cr/Co2FeAl interface due to the MgO capping layer. Meanwhile, Δ1 Bloch state in the majority spin and Δ2' Bloch state in the minority spin contribute to the short (≈2.1 and ≈1.9 nm) and long oscillatory period (≈4.0 nm) in the disordered B2 Co2FeAl multilayers, respectively. [ABSTRACT FROM AUTHOR]

Keywords: photoreceptors; photobody; cryptochromes; phase separation; NMR EN photoreceptors photobody cryptochromes phase separation NMR 460 462 3 02/23/23 20230301 NES 230301 In plants, cryptochromes (CRYs) are blue light receptors that regulate various developmental progress. (g) Speckles morphology of CRY2 N538-R557-EGFP and CRY2 N538-R557-EGFP+T-NLS in Arabidopsis protoplasts. The introduction of CRY2-EGFP but not EGFP, CRY2 SP PHR sp -EGFP+T-NLS or CRY2 SP D387A sp -EGFP rescued the long hypocotyl phenotype. [Extracted from the article]

Phosphate (Pi) starvation response (PHR) transcription factors play key roles in plant Pi homeostasis maintenance. They are negatively regulated by stand-alone SPX proteins, cellular receptors for inositol pyrophosphate (PP-InsP) nutrient messengers. How PP-InsP-bound SPX interacts with PHRs is poorly understood. Here, we report crystal structures of the rice SPX2/InsP6/PHR2 complex and of the PHR2 DNA binding (MYB) domain in complex with target DNA at resolutions of 3.1 Å and 2.7 Å, respectively. In the SPX2/InsP6/PHR2 complex, the signalling-active SPX2 assembles into a domain-swapped dimer conformation and binds two copies of PHR2, targeting both its coiled-coil (CC) oligomerisation domain and MYB domain. Our results reveal that the SPX2 senses PP-InsPs to inactivate PHR2 by establishing severe steric clashes with the PHR2 MYB domain, preventing DNA binding, and by disrupting oligomerisation of the PHR2 CC domain, attenuating promoter binding. Our findings rationalize how PP-InsPs activate SPX receptor proteins to target PHR family transcription factors. SPX receptors regulate plant phosphate response via PHR transcription factors. Here, based on crystal structure analysis of rice PHR2 complexes, the authors propose that SPX2 regulates PHR2 by preventing DNA binding and oligomerisation of the PHR2 CC domain. [ABSTRACT FROM AUTHOR]

Perpendicular magnetic tunnel junctions (pMTJs) with synthetic antiferromagnetic (SAF) free layers have attracted much interest for applications on spintronic memory devices with ultrafast speed and ultralow energy. In this work, SAF free layer pMTJs (SAF-pMTJs) were designed and fabricated, in which a Ru/Ta bilayer spacer is used to form the SAF structure. We first characterized the magnetization dynamics of the SAF free layer by using ferromagnetic resonance and found that the Gilbert damping constant of the SAF free layer is around 0.019. Then, in device level studies that span from 900 nm down to 200 nm lateral size, we observed a transition of the SAF free layer from a preferred antiparallel to parallel magnetic configuration at small device sizes, which can be explained by the increased dipole interaction. The impact of the operating current was also investigated. We report an extraordinarily strong dependence, up to 144.1 kOe per A/ μ m2, of the offset field on the applied current, suggesting an electric-field modulation on the interlayer exchange coupling of the SAF free layer. These results will be instructive to improve the understanding of material properties and device performance of SAF-pMTJs for ultrafast, ultralow-power consumption spintronic devices. [ABSTRACT FROM AUTHOR]

Various kinds of cap structures, such as m7G, triphosphate groups, NAD and dpCoA, protect the 5′ terminus of RNA. The cap structures bond covalently to RNA and affect its stability, translation, and transport. The removal of the caps is mainly executed by Nudix hydrolase family proteins, including Dcp2, RppH and NudC. Numerous efforts have been made to elucidate the mechanism underlying the removal of m7G, triphosphate group, and NAD caps. In contrast, few studies related to the cleavage of the RNA dpCoA cap have been conducted. Here, we report the hydrolytic activity of Escherichia coli NudC towards dpCoA and dpCoA-capped RNA in vitro. We also determined the crystal structure of dimeric NudC in complex with dpCoA at 2.0 Å resolution. Structural analysis revealed that dpCoA is recognized and hydrolysed in a manner similar to NAD. In addition, NudC may also remove other dinucleotide derivative caps of RNA, which comprise the AMP moieties. NudC homologs in Saccharomyces cerevisiae and Arabidopsis thaliana exhibited similar dpCoA decapping (deCoAping) activity. These results together indicate a conserved mechanism underpinning the hydrolysis of dpCoA-capped RNA in both prokaryotes and eukaryotes. [ABSTRACT FROM AUTHOR]

Summary: Cellulose is one of the most abundant organic polymers in nature. It contains multiple β‐1,4‐glucan chains synthesized by cellulose synthases (CesAs) on the plasma membrane of higher plants. CesA subunits assemble into a pseudo‐sixfold symmetric cellulose synthase complex (CSC), known as a 'rosette complex'. The structure of CesA remains enigmatic. Here, we report the cryo‐EM structure of the homotrimeric CesA7 from Gossypium hirsutum at 3.5‐angstrom resolution. The GhCesA7 homotrimer shows a C3 symmetrical assembly. Each protomer contains seven transmembrane helices (TMs) which form a channel potentially facilitating the release of newly synthesized glucans. The cytoplasmic glycosyltransferase domain (GT domain) of GhCesA7 protrudes from the membrane, and its catalytic pocket is directed towards the TM pore. The homotrimer GhCesA7 is stabilized by the transmembrane helix 7 (TM7) and the plant‐conserved region (PCR) domains. It represents the building block of CSCs and facilitates microfibril formation. This structure provides insight into how eukaryotic cellulose synthase assembles and provides a mechanistic basis for the improvement of cotton fibre quality in the future. [ABSTRACT FROM AUTHOR]

Summary: The mechanism that coordinates cell growth and cell cycle progression remains poorly understood; in particular, whether the cell cycle and cell wall biosynthesis are coordinated remains unclear. Recently, cell wall biosynthesis and cell cycle progression were reported to respond to wounding. Nonetheless, no genes are reported to synchronize the biosynthesis of the cell wall and the cell cycle. Here, we report that wounding induces the expression of genes associated with cell wall biosynthesis and the cell cycle, and that two genes, AtMYB46 in Arabidopsis thaliana and RrMYB18 in Rosa rugosa, are induced by wounding. We found that AtMYB46 and RrMYB18 promote the biosynthesis of the cell wall by upregulating the expression of cell wall‐associated genes, and that both of them also upregulate the expression of a battery of genes associated with cell cycle progression. Ultimately, this response leads to the development of curled leaves of reduced size. We also found that the coordination of cell wall biosynthesis and cell cycle progression by AtMYB46 and RrMYB18 is evolutionarily conservative in multiple species. In accordance with wounding promoting cell regeneration by regulating the cell cycle, these findings also provide novel insight into the coordination between cell growth and cell cycle progression and a method for producing miniature plants. Significance Statement: How the cell growth and cell cycle progression are coordinated still is one of the remaining great conundrums.Whether there is an interplay between cell cycle and cell wall synthesis is remain unclear. To clarify the relationship between cell growth and cell cycle will be of great significance for rational manipulation of plant growth and shape. Here, we report two wounded‐induced transcription factors, AtMYB46 in Arabidopsis thaliana and RrMYB18 in Rosa rugosa, promote the biosynthesis of the cell wall by up‐regulating the expression of cell wall associated genes, and also up‐regulate the expression of a battery of genes associated with cell cycle progression. Ultimately, this response leads to the change of plant growth and shape. We also found that the coordination of cell wall biosynthesis and cell cycle progression is evolutionarily conservative in multiple species. These findings provide novel insight into the coordination between cell growth and cell cycle progression and a method for producing miniature plants. [ABSTRACT FROM AUTHOR]

Development of L10 FePd thin films with large bulk perpendicular magnetic anisotropy and a low damping constant may permit superior scaling of next-generation ultra-high density magnetic memory elements. The buffer layer influences the L10-order parameter, static and dynamic magnetic properties of FePd and demands consideration for the design of high anisotropy strength and low damping films. In this report, we systematically investigate the perpendicular magnetic anisotropy and damping constant of the FePd thin films engineered through the Cr/(Pt, Ru, Ir, Rh), Mo/Ir, and Ir buffer layers. We observed that the Ir(001), Cr(001)/Ir(001), Cr(001)/Pt(001), Cr(001)/Rh(001), and Cr(001)/Ru(001) buffer layers can induce highly oriented (001) FePd films while the Mo/Ir buffer layer does not. Of all the buffer layers, the largest perpendicular magnetic anisotropy Ku ∼ 1.2 MJ/m3 and damping constant α ∼ 0.005 were achieved for the Cr/Pt buffered FePd sample, consistent with a high ordering parameter S ∼ 0.82. The Cr/Ru buffered FePd sample shows the lowest α ∼ 0.008, despite having a lower S ∼ 0.64 and a lower Ku ∼ 0.9 MJ/m3. These film-level properties would be sufficient for the engineering of devices that require thermally stable, sub-10 nm lateral size elements with low damping for applications of low energy-delay magnetic memory devices. [ABSTRACT FROM AUTHOR]

Various kinds of cap structures, such as m7G, triphosphate groups, NAD and dpCoA, protect the 5′ terminus of RNA. The cap structures bond covalently to RNA and affect its stability, translation, and transport. The removal of the caps is mainly executed by Nudix hydrolase family proteins, including Dcp2, RppH and NudC. Numerous efforts have been made to elucidate the mechanism underlying the removal of m7G, triphosphate group, and NAD caps. In contrast, few studies related to the cleavage of the RNA dpCoA cap have been conducted. Here, we report the hydrolytic activity of Escherichia coli NudC towards dpCoA and dpCoA-capped RNA in vitro. We also determined the crystal structure of dimeric NudC in complex with dpCoA at 2.0 Å resolution. Structural analysis revealed that dpCoA is recognized and hydrolysed in a manner similar to NAD. In addition, NudC may also remove other dinucleotide derivative caps of RNA, which comprise the AMP moieties. NudC homologs in Saccharomyces cerevisiae and Arabidopsis thaliana exhibited similar dpCoA decapping (deCoAping) activity. These results together indicate a conserved mechanism underpinning the hydrolysis of dpCoA-capped RNA in both prokaryotes and eukaryotes. [ABSTRACT FROM AUTHOR]

In this work, we study the effects of mobile oxygen ions in a synthetic antiferromagnet structure gated by a sputtered SiO2 dielectric layer for memory and logic applications. Our devices utilize electrochemical reactions between dielectric reactive species and magnetic elements to create irreversible changes in magnetization. We analyzed the dependence of ion velocity on the gate dielectric properties such as the lattice parameter, oxygen migration energy barrier, and electric field (E-field). Hall bar devices were patterned and tested to determine the interlayer exchange coupling between the CoFeB and [Co/Pd]n layers. The anomalous Hall effect (AHE) of the CoFeB layer at different gate voltages (Vg) was measured to determine the Vg dependence. A sharp change in the behavior of the CoFeB layer with respect to negative Vg results in a non-reciprocal decrease in the coercivity and magnetization and an increase in exchange bias. The observed change in exchange bias field and magnetization allows us to measure the change in the effective thickness of the CoFeB layer. This led us to conclude that the source of such behavior is the negatively charged mobile oxygen ions from the SiO2 gate. [ABSTRACT FROM AUTHOR]

Extensive studies have revealed that cognitive processing was impaired after anesthesia and surgery, particularly for the elderly patients. However, most of the existing studies focused on the general cognitive deficits (e.g., delayed neuro-cognitive recovery and POCD). Although diagnosis of social abilities has been used in various clinical fields, few studies have investigated the potential deficit on social cognition after anesthesia and surgery. The current study examined whether there was any social cognitive dysfunction after anesthesia and surgery. We achieved this by taking biological motion (BM) as the stimuli of interest, the perception of which has been taken as the hallmark of social cognition. The elderly patients (aged ≥ 60 years) were required to judge whether an upright BM stimulus appeared among the dynamic noises to test their social cognition, as well as do a Mini-Mental State Examination to test their general cognition. The two tests were performed at both 1-day before and 7-day after the surgery. Results showed that 31.25% of patients exhibited BM perception deficit after anesthesia and surgery relative to before anesthesia and surgery, implying that social cognitive dysfunction existed. Meanwhile, social cognitive dysfunction was independent from delayed neurocognitive recovery. [ABSTRACT FROM AUTHOR]

Bulk perpendicular magnetic anisotropy materials are proposed to be a promising candidate for next-generation ultrahigh density and ultralow energy-consumption spintronic devices. In this work, we experimentally investigate the structure, thermal stability, and magnetic properties of FePd thin films seeded by an Ru layer. An fcc-phase Ru layer induces the highly-ordered L10-phase FePd thin films with perpendicular magnetic anisotropy (Ku ∼10.1 Merg/cm3). The thermal stability of FePd samples is then studied through the annealing process. It is found that a Ku ∼6.8 Merg/cm3 can be obtained with an annealing temperature of 500 °C. In addition, the Gilbert damping constant α, an important parameter for switching current density, is determined as a function of the testing temperature. We observe that α increases from 0.006 to 0.009 for the as-deposited FePd sample and from 0.006 to 0.012 for the 400 °C-annealed FePd sample as the testing temperature changes from 25 °C to 150 °C. These results suggest that Ru-seeded FePd provides great potential in scaling perpendicular magnetic tunnel junctions below 10 nm for applications in ultralow energy-consumption spintronic devices. [ABSTRACT FROM AUTHOR]

MS5 is a meiosis‐related protein belonging to the Brassicaceae‐specific domain of unknown function family and characterized by the MS5 superfamily domain (MSD). In this study, we elucidated the three‐dimensional crystal structure and potential biochemical function of the MSD. It was observed that the MSD adopts a cystatin‐like fold, mainly consisting of a central α‐helix and four‐ or five‐stranded antiparallel β‐sheets that wrap around it. However, unlike cystatins, which inhibit cysteine proteases, the MSD displayed allosteric activation of papain. We believe that our study provides insight into novel mechanisms of proteolytic enzyme regulation and may serve as a basis for functional studies of the MS5 family proteins in plants. [ABSTRACT FROM AUTHOR]

Thick plate bending process (warm bending and tempering) has a profound impact on the material strength distribution (MSD) in hydrogenation reactor shells. To date, few studies have studied the thick plate bending process. In this work, an artificial neural network (ANN) combined with finite element analysis (FEA) was utilized to investigate the impact of thick plate bending on the MSD of reactor shells. First, tensile tests of 0-10% pre-strained 2.25Cr-1Mo-0.25 V specimens were subjected to 390 to 510 °C. The results obtained from this experiment were used to develop ANN with two inputs (temperature and plastic strain) to predict the strength of pre-deformed steel. Subsequently, the plastic strain distribution of reactor shells after warm bending was obtained via FEA. We then inputted the FEA results into well-established ANN to predict the MSD of un-tempered reactor shells. The MSD of an actual tempered reactor shell was measured to study the synergic effect of warm bending and tempering on MSD variation. Results showed that the average absolute relative errors between the proposed ANN and tensile test results were below 4%. The absolute relative errors of the proposed prediction method varied from 0.24 to 7.88%. The proposed method is therefore reliable in the lightweight design of the hydrogenation reactor. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) is a key phytohormone that mediates environmental stress responses. Vitamin C, or L-ascorbic acid (AsA), is the most abundant antioxidant protecting against stress damage in plants. How the ABA and AsA signaling pathways interact in stress responses remains elusive. In this study, we characterized the role of a previously unidentified gene, PTPN (PTP-like Nucleotidase) in plant drought tolerance. In Arabidopsis , (AtPTPN was expressed in multiple tissues and upregulated by ABA and drought treatments. Loss-of-function mutants of AtPTPN were hyposensitive to ABA but hypersensitive to drought stresses, whereas plants with enhanced expression of AtPTPN showed opposite phenotypes to. Overexpression of maize PTPN (ZmPTPN) promoted, while knockdown of ZmPTPN inhibited plant drought tolerance, indicating conserved and positive roles of PTPN in plant drought tolerance. We found that both AtPTPN and ZmPTPN release Pi by hydrolyzing GDP/GMP/dGMP/IMP/dIMP, and that AtPTPN positively regulated AsA production via endogenous Pi content control. Consistently, overexpression of VTC2 , the rate-limiting synthetic enzyme in AsA biosynthesis, promoted AsA production and plant drought tolerance, and these effects were largely dependent on AtPTPN activity. Furthermore, we demonstrated that the heat shock transcription factor HSFA6a directly binds the AtPTPN promoter and activates AtPTPN expression. Genetic analyses showed that AtPTPN is required for HSFA6a to regulate ABA and drought responses. Taken together, our data indicate that PTPN-mediated crosstalk between the ABA signaling and AsA biosynthesis pathways positively controls plant drought tolerance. How ABA and vitamin C signaling pathways interact in stress responses remains elusive. This study demonstrates that a PTP-like Nucleotidase (PTPN) gene, which is activated by the ABA signaling pathway, encodes a key regulator of drought-promoted vitamin C production. The PTPN mediated crosstalk between the ABA signaling and vitamin C biosynthesis pathways positively regulates plant drought tolerance. [ABSTRACT FROM AUTHOR]

We studied the spin-to-charge and charge-to-spin conversion at room temperature in sputtered WTe2−x (x = 0.8) (t)/Co20Fe60B20(6 nm) heterostructures. Spin pumping measurements were used to characterize the spin-to-charge efficiency, and the spin efficiency was calculated to be larger than ∼0.035. Second harmonic Hall measurements were carried out to estimate the charge-to-spin conversion ratio. We found that the system exhibits a large field-like torque (spin torque efficiency ∼0.1) and small damping-like torque (spin torque efficiency ∼0.001) compared to those reported for heavy metals. High-resolution transmission electron microscopy images show that the WTe2−x layer is amorphous, which may enhance the spin swapping effect by inducing large interfacial spin–orbit scattering, thus contributing to a large field-like torque. [ABSTRACT FROM AUTHOR]

Holliday junctions (HJs) are key DNA intermediates in genetic recombination and are eliminated by nuclease, termed resolvase, to ensure genome stability. HJ resolvases have been identified across all kingdoms of life, members of which exhibit sequence-dependent HJ resolution. However, the molecular basis of sequence selectivity remains largely unknown. Here, we present the chloroplast resolvase MOC1, which cleaves HJ in a cytosine-dependent manner. We determine the crystal structure of MOC1 with and without HJs. MOC1 exhibits an RNase H fold, belonging to the retroviral integrase family. MOC1 functions as a dimer, and the HJ is embedded into the basic cleft of the dimeric enzyme. We characterize a base recognition loop (BR loop) that protrudes into and opens the junction. Residues from the BR loop intercalate into the bases, disrupt the C-G base pairing at the crossover and recognize the cytosine, providing the molecular basis for sequence-dependent HJ resolution by a resolvase. Holliday junctions (HJs) are DNA intermediates in genetic recombination that are resolved by nuclease, termed resolvase, to ensure genome stability. Here, the authors provide insights into the resolution process by resolving the crystal structure of the chloroplast resolvase MOC1 with HJs substrates. [ABSTRACT FROM AUTHOR]

Recently, two-dimensional (2D) materials have attracted considerable interest for use in spintronic applications, especially hexagonal close-packed (hcp)-phase boron nitride (BN) as a tunnel barrier. In this paper, we experimentally investigated the structural properties of a sputtered hcp-BN thin film. By optimizing the experimental conditions, we obtained the stoichiometric BN thin film with a ratio of 1:1 of the Ar/N2 sputtering gas. Then the Co/BN/Co magnetic tunnel junction (MTJ) stacks were prepared to study the crystalline structure of the BN tunnel barrier and their epitaxial relationship. We found that the as-deposited BN tunnel barrier layer follows the texture of the bottom Co layer and forms a polycrystalline structure. After the high-temperature treatment of the MTJ stack, texturing of the BN tunnel barrier layer is observed, however, this annealing process makes the BN tunnel barrier noncontinuous and induces serious interdiffusion between layers. These results will open the door for development of spintronic devices based on MTJs with hcp-phase BN tunnel barrier and hcp-phase perpendicular magnetic anisotropy ferromagnetic layer. [ABSTRACT FROM AUTHOR]

Materials such as L10 Fe-based alloys with perpendicular magnetic anisotropy derived from crystal structure have the potential to deliver higher thermal stability of magnetic memory elements compared to materials whose anisotropy is derived from surfaces and interfaces. A number of processing parameters enable control of the quality and texture of L10 FePd; among them are substrate, deposition temperature, pressure, and seed and buffer layer. The angle of inclination between the substrate and the sputtering target can also impact the texture of L10 crystallization of sputtered FePd and magnetic properties of the derived thin films. This letter examines the difference between FePd layers that have been magnetron sputter deposited on Cr(15 nm)/Pt, Ir, or Ru(4 nm)/FePd (8 nm)/Ru(2 nm)/Ta(3 nm) substrate layers at an oblique angle (30° tilt from the sputtering target) versus normal incidence (target facing the substrate). X-ray diffraction, ferromagnetic resonance spectroscopy, and vibrating sample magnetometry were used to compare the degree of L10 order and static and dynamic properties of films deposited under both conditions. The films grown using the oblique orientation exhibit stronger degree of L10 orientation, larger magnetic anisotropy energy, and lower Gilbert damping, on all three buffer layers. [ABSTRACT FROM AUTHOR]

Background: N6-methyladenosine (m6A) modification, the most abundant internal methylation of eukaryotic RNA transcripts, is critically implicated in RNA processing. As the largest known component in the m6A methyltransferase complex, KIAA1429 plays a vital role in m6A methylation. However, its function and mechanism in hepatocellular carcinoma (HCC) remain poorly defined. Methods: Quantitative PCR, western blot and immunohistochemistry were used to measure the expression of KIAA1429 in HCC. The effects of KIAA1429 on the malignant phenotypes of hepatoma cells were examined in vitro and in vivo. MeRIP-seq, RIP-seq and RNA-seq were performed to identify the target genes of KIAA1429. Results: KIAA1429 was considerably upregulated in HCC tissues. High expression of KIAA1429 was associated with poor prognosis among HCC patients. Silencing KIAA1429 suppressed cell proliferation and metastasis in vitro and in vivo. GATA3 was identified as the direct downstream target of KIAA1429-mediated m6A modification. KIAA1429 induced m6A methylation on the 3′ UTR of GATA3 pre-mRNA, leading to the separation of the RNA-binding protein HuR and the degradation of GATA3 pre-mRNA. Strikingly, a long noncoding RNA (lncRNA) GATA3-AS, transcribed from the antisense strand of the GATA3 gene, functioned as a cis-acting element for the preferential interaction of KIAA1429 with GATA3 pre-mRNA. Accordingly, we found that the tumor growth and metastasis driven by KIAA1429 or GATA3-AS were mediated by GATA3. Conclusion: Our study proposed a complex KIAA1429-GATA3 regulatory model based on m6A modification and provided insights into the epi-transcriptomic dysregulation in hepatocarcinogenesis and metastasis. [ABSTRACT FROM AUTHOR]

Regenerable adsorbents with rapid adsorption are highly desirable for water treatment. Cyclodextrin-based adsorbents have been attracting increasing attention because of their high affinity for a variety of organic compounds. All previously reported porous cyclodextrin-based polymers were synthesized in the organic phase, which required a long reaction time and high cost and resulted in an adverse impact on the environment. In this study, a novel macroporous and ultra-microporous beta-cyclodextrin-based polymer (T-E-CDP) was prepared in the aqueous phase for the first time by simultaneously crosslinking beta-cyclodextrin with both flexible and rigid crosslinkers. Owing to the porous structure and easy access of adsorption sites, T-E-CDP exhibited ultra-rapid adsorption of organic micro-pollutants, such as bisphenol A (BPA), 3-phenylphenol (3-PH), and ethinyl estradiol (EE2), with an adsorption rate constant 45 and 581 times those of the commercial adsorbents, activated carbon and XAD-4 resin, respectively. The polymer adsorbent could be easily regenerated by methanol at room temperature and reused many times without a significant decrease in the adsorption performance. More importantly, T-E-CDP could effectively remove many organic pollutants from water at environmentally relevant concentrations and without being affected by the pH level, ionic strength, and humic acid concentration, indicating that it is very suitable for application in practical water treatment. It is particularly important that T-E-CDP can be easily degraded without causing secondary pollution after use, and the synthesis process of T-E-CDP is green, low-cost, and easy to industrialize. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A), a ubiquitous RNA modification, is installed by METTL3-METTL14 complex. The structure of the heterodimeric complex between the methyltransferase domains (MTDs) of METTL3 and METTL14 has been previously determined. However, the MTDs alone possess no enzymatic activity. Here we present the solution structure for the zinc finger domain (ZFD) of METTL3, the inclusion of which fulfills the methyltransferase activity of METTL3-METTL14. We show that the ZFD specifically binds to an RNA containing 5′-GGACU-3′ consensus sequence, but does not to one without. The ZFD thus serves as the target recognition domain, a structural feature previously shown for DNA methyltransferases, and cooperates with the MTDs of METTL3-METTL14 for catalysis. However, the interaction between the ZFD and the specific RNA is extremely weak, with the binding affinity at several hundred micromolar under physiological conditions. The ZFD contains two CCCH-type zinc fingers connected by an anti-parallel β-sheet. Mutational analysis and NMR titrations have mapped the functional interface to a contiguous surface. As a division of labor, the RNA-binding interface comprises basic residues from zinc finger 1 and hydrophobic residues from β-sheet and zinc finger 2. Further we show that the linker between the ZFD and MTD of METTL3 is flexible but partially folded, which may permit the cooperation between the two domains during catalysis. Together, the structural characterization of METTL3 ZFD paves the way to elucidate the atomic details of the entire process of RNA m6A modification. [ABSTRACT FROM AUTHOR]

The impact of hot bending forming process on the high-temperature mechanical properties and hydrogen damage of 2.25Cr-1Mo-0.25V steel was investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), energy-dispersive spectrum (EDS) and the slow strain rate tensile (SSRT) test in high-temperature hydrogen environment. The samples containing hot bending residual influence were extracted from a real hydrogenation reactor shell fabricated through hot bending-welding process. SEM images of the material demonstrated that the density and size of carbides in 2.25Cr-1Mo-0.25V increased after forming. TEM and EDS results revealed that ferrite matrix of the formed material was purified. The mechanical properties measured by SSRT test manifested that 2.25Cr-1Mo-0.25V was softened after forming. Moreover, it was observed that high-temperature hydrogen environment embrittled the material and the susceptibility to hydrogen damage increased after forming. The role of hot bending process on the evolution of mechanical properties and hydrogen damage susceptibility was discussed. Possible mechanism for the impact of hot bending process on the high-temperature hydrogen damage was proposed. [ABSTRACT FROM AUTHOR]