The manipulation of spin textures with electric currents is an important challenge in the field of spintronics. Many attempts have been made to electrically drive magnetic domain walls in ...ferromagnets, yet the necessary current density remains quite high (~10(7) A cm(-2)). A recent neutron study combining Hall effect measurements has shown that an ultralow current density of J~10(2) A cm(-2) can trigger the rotational and translational motion of the skyrmion lattice in MnSi, a helimagnet, within a narrow temperature range. Raising the temperature range in which skyrmions are stable and reducing the current required to drive them are therefore desirable objectives. Here we demonstrate near-room-temperature motion of skyrmions driven by electrical currents in a microdevice composed of the helimagnet FeGe, by using in-situ Lorentz transmission electron microscopy. The rotational and translational motions of skyrmion crystal begin under critical current densities far below 100 A cm(-2).
AbstractCyclic loading is encountered in several practical geotechnical problems. Understanding and modeling cyclic soil responses are key to engineering analysis and design. As one of the most ...distinct features of soils, fabric anisotropy plays an essential role in the soil response to cyclic loading, such as pore-pressure development dependent on the interplay between fabric and loading direction, effective stress path inclination related to initial fabric, and stiffness variation associated with bedding-plane orientation. However, most previous clay models developed within the bounding surface framework use the rotational angle, a stress-ratio-type scalar, to describe fabric anisotropy and its evolution, which fails to comprehensively capture the anisotropic responses. In this study, a deviatoric fabric tensor, instead of the commonly used rotational angle, was used to describe the internal microstructure within the framework of anisotropic critical state theory. A scalar-valued anisotropic fabric variable quantifying the interplay between the fabric tensor and loading direction was used to account for the impact of anisotropy on both dilatancy and strength, aimed at simulating the typical ‘butterfly-shaped’ stress loops, and varying rates of stiffness degradation and pore-pressure accumulation of samples with different bedding-plane directions. The initial fabric tensor was also introduced into the elastic expression to replicate the inclined undrained stress paths, as well as the variational degree and direction of inclinations due to different bedding-plane orientations. The predictive capability of the proposed model was demonstrated by simulating three typical clays in undrained and drained conditions, with varying stress and strain amplitudes. The model can capture the major influences from the initial fabric anisotropy and its evolution of clay, i.e., the typical ‘butterfly-shaped’ stress loops and the bedding-plane direction-dependent effective stress path, the pore-pressure generation, stiffness variation, and strain accumulation.
Manipulating topological spin textures is a key for exploring unprecedented emergent electromagnetic phenomena. Whereas switching control of magnetic skyrmions, e.g., the transitions between a ...skyrmion-lattice phase and conventional magnetic orders, is intensively studied towards development of future memory device concepts, transitions among spin textures with different topological orders remain largely unexplored. Here we develop a series of chiral magnets MnSi
Ge
, serving as a platform for transitions among skyrmion- and hedgehog-lattice states. By neutron scattering, Lorentz transmission electron microscopy and high-field transport measurements, we observe three different topological spin textures with variation of the lattice constant controlled by Si/Ge substitution: two-dimensional skyrmion lattice in x = 0-0.25 and two distinct three-dimensional hedgehog lattices in x = 0.3-0.6 and x = 0.7-1. The emergence of various topological spin states in the chemical-pressure-controlled materials suggests a new route for direct manipulation of the spin-texture topology by facile mechanical methods.
Chirality--that is, left- or right-handedness--is an important concept in a broad range of scientific areas. In condensed matter, chirality is found not only in molecular or crystal forms, but also ...in magnetic structures. A magnetic skyrmion is a topologically stable spin vortex structure, as observed in chiral-lattice helimagnets, and is one example of such a structure. The spin swirling direction (skyrmion helicity) should be closely related to the underlying lattice chirality via the relativistic spin-orbit coupling. Here, we report on the correlation between skyrmion helicity and crystal chirality in alloys of helimagnets Mn(1-x)Fe(x)Ge with varying compositions by Lorentz transmission electron microscopy and convergent-beam electron diffraction over a broad range of compositions (x = 0.3-1.0). The skyrmion lattice constant shows non-monotonous variation with composition x, with a divergent behaviour around x = 0.8, where the correlation between magnetic helicity and crystal chirality changes sign. This originates from continuous variation of the spin-orbit coupling strength and its sign reversal in the metallic alloys as a function of x. Controllable spin-orbit coupling may offer a promising way to tune skyrmion size and helicity.
•Two different thermal conditions are established to explore the lithium-ion battery performance.•Battery pack without BTMS intervention may have an excellent discharging performance.•Battery ...charging performance is independent on the charging temperature ranged from 20 °C to 40 °C.•The irreversible heat can be regarded as the sole heat source term to simplify battery thermal model.
The relationship between lithium-ion battery performance and operating temperature is of significance in designing battery thermal management system (BTMS). In this study, two different thermal conditions, namely constant temperature condition and near-adiabatic condition are established to explore charging/discharging characteristics and heat generation behaviors of the lithium-ion battery with Li(NixCoyAlz)O2 cathode. The objective of creating near-adiabatic condition is to discover the effect of the heat generated by battery itself on charging/discharging characteristics. The experimental results show that the battery charging characteristics are nearly independent on the charging temperature ranged from 20 °C to 40 °C, while the battery charging/discharging performance degrade dramatically for the battery temperature lower than 20 °C. Although the heat generated by battery itself may accelerate battery degradation during cycling due to the adverse effect of excessive temperature, however it improves the discharging performance in a suitable temperature range. This implies that a battery pack may have an excellent discharging performance without BTMS intervention at a moderate discharging rate (e.g., 0.5 C). The irreversible heat could be regarded as the sole heat source term to simplify the battery thermal model due to negligible thermal effect caused by the small amount of reversible heat when the battery is discharged at higher discharging rates.
Aims
Plant tissues are the reservoirs of beneficial and harmful microbes that regulates plant growth. In the present study, we investigated the diversity, function and colonization of sugarcane roots ...associated with Bacillus spp.
Methods and Results
A total of 20 Bacillus strains were isolated and identified by 16S rRNA gene sequencing, and their genetic diversity was examined by BOX, ERIC, REP, (GTG)5 PCR techniques. Among all Bacillus isolates, 65% showed indole acetic acid‐like compounds production, 50% solubilized phosphorus and 25% of the isolates were able to secrete siderophore. Moreover, all 20 Bacillus isolates showed antifungal activity against eight fungal pathogens and 11 of them (55%) antagonized tomato grey mold. Based on the plant growth‐promoting traits and antifungal potential, isolate Y8 was selected for root and plant tissue colonization assays and a greenhouse‐level sugarcane growth promotion study. Fluorescence microscopy results confirmed that isolate Y8 has a strong ability to colonize in the sugarcane root and leaves, and the root surface association of Y8 was confirmed by scanning electron microscopy. Furthermore, greenhouse experimental results demonstrated that Y8 has a significant effect on enhancing sugarcane biomass and root length.
Conclusions
Endophytic Bacillus strains have growth‐promoting properties and anti‐fungal ability that can enhance plant fitness in an eco‐friendly manner.
Significance and Impact of the Study
Endophytic Bacillus strains would be a potential alternative to chemical fertilizer as well as a biocontrol agent in the future.
Summary
Dysfunction of the immune regulatory system plays an important role in the pathogenesis of rheumatoid arthritis (RA). Vasoactive intestinal peptide (VIP) has multiple bioactivities. This ...study aims to investigate the role of VIP in the maintenance of the immune regulatory capacity of monocytes (Mos). Human peripheral blood samples were collected from RA patients and healthy control (HC) subjects. Mos and CD14+ CD71–CD73+CD25+ regulatory Mos (RegMos) were isolated from the blood samples and characterized by flow cytometry. A rat RA model was developed to test the role of VIP in the maintenance of the immune regulatory function of Mos. The results showed that RegMos of HC subjects had immune suppressive functions. RegMos of RA patients expressed less interleukin (IL)‐10 and showed an incompetent immune regulatory capacity. Serum levels of VIP were lower in RA patients, which were positively correlated with the expression of IL‐10 in RegMos. In‐vitro experiments showed that the IL‐10 mRNA decayed spontaneously in RegMos, which could be prevented by the presence of VIP in the culture. VIP suppressed the effects of tristetraprolin (TTP) on inducing IL‐10 mRNA decay in RegMos. Administration of VIP inhibited experimental RA in rats through restoring the IL‐10 expression in RegMos. RegMos have immune suppressive functions. VIP is required in maintaining IL‐10 expression in RegMos. The data suggest that VIP has translational potential in the treatment of immune disorders such as RA.
A fraction of peripheral monocyte has immune regulatory function, which is impaired in patients with rheumatoid arthritis.
Abstract
The fast transitions between different types of quasi-periodic oscillations (QPOs) are generally observed in black hole transient sources (BHTs). We present a detailed study of the timing ...and spectral properties of the transitions of type-B QPOs in MAXI J1348–630, observed by Insight-HXMT. The fractional rms variability–energy relationship and energy spectra reveal that type-B QPOs probably originate from jet precession. Compared to a weak power-law dominated power spectrum, when type-B QPOs are present, the corresponding energy spectrum shows an increase in the Comptonization component and the need for the
xillverCp
component, and a slight increase in the height of the corona when using the
relxilllp
model. Therefore, we suggest that a coupled inner disk-jet region is responsible for the observed type-B QPO transitions. The timescale for the appearance/disappearance of type-B QPOs is either long or short (seconds), which may indicate instability of the disk-jet structure. For these phenomena, we hypothesize that the Bardeen–Petterson effect causes the disk-jet structure to align with the BH spin axis or that the disappearance of small-scale jets bound by the magnetic flux tubes leads to the disappearance of type-B QPOs. We observed three events regarding the B/C transitions, one of which occurred over a short time period from ∼9.2 Hz (C) to ∼4.8 Hz (B). The energy spectral analysis for the other two transitions shows that when type-C QPO is present, the Comptonization flux is higher, the spectrum is harder, and the inner radius of the disk changes insignificantly. We suggest that type-C QPOs probably originate from relatively stronger jets or the corona.
Cell-cell communication via ligand-receptor signaling is a fundamental feature of complex organs. Despite this, the global landscape of intercellular signaling in mammalian liver has not been ...elucidated. Here we perform single-cell RNA sequencing on non-parenchymal cells isolated from healthy and NASH mouse livers. Secretome gene analysis revealed a highly connected network of intrahepatic signaling and disruption of vascular signaling in NASH. We uncovered the emergence of NASH-associated macrophages (NAMs), which are marked by high expression of triggering receptors expressed on myeloid cells 2 (Trem2), as a feature of mouse and human NASH that is linked to disease severity and highly responsive to pharmacological and dietary interventions. Finally, hepatic stellate cells (HSCs) serve as a hub of intrahepatic signaling via HSC-derived stellakines and their responsiveness to vasoactive hormones. These results provide unprecedented insights into the landscape of intercellular crosstalk and reprogramming of liver cells in health and disease.
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•Heterogeneity and plasticity of non-parenchymal cells in healthy and NASH liver•Landscape of intrahepatic ligand-receptor signaling at single-cell resolution•Emergence of Trem2+ NASH-associated macrophages (NAMs) in mouse and human NASH•Stellakine secretion and contractile response to vasoactive hormones by HSCs
This work illustrates the heterogeneity of liver non-parenchymal cells (NPCs) and their reprogramming during NASH pathogenesis. Using single-cell RNA-sequencing analysis, the authors mapped the landscape of the intrahepatic ligand-receptor signaling network and revealed two fundamental aspects of HSC biology: stellakine secretion and contractile response to vasoactive hormones. Hepatic vascular dysfunction and emergence of Trem2+ NASH-associated macrophages (NAMs) are two conserved features of mouse and human NASH.
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