A Complex Concentrated Alloy with Record-High Strength-Toughness at 77 K.

High strength and large ductility, leading to a high material toughness (area under the stress-strain curve), are desirable for alloys used in cryogenic applications. Assisted by domain-knowledge-informed machine learning, here a complex concentrated FeCoNiAlTa alloy is designed, which uses L1 coherent nanoprecipitates in a high volume fraction (≈65 ± 3 vol.%) in a face-centered-cubic (FCC) solid solution matrix that undergoes FCC-to-body-centered-cubic (BCC) phase transformation upon tensile straining.

Remarkable flexibility in freestanding single-crystalline antiferroelectric PbZrO membranes.

The ultrahigh flexibility and elasticity achieved in freestanding single-crystalline ferroelectric oxide membranes have attracted much attention recently. However, for antiferroelectric oxides, the flexibility limit and fundamental mechanism in their freestanding membranes are still not explored clearly. Here, we successfully fabricate freestanding single-crystalline PbZrO membranes by a water-soluble sacrificial layer technique.

Deformation Coupled Moiré Mapping of Superlubricity in Graphene.

The ultralow friction of two-dimensional (2D) materials, commonly referred to as superlubricity, has been associated with Moiré superlattices (MSLs). While MSLs have been shown to play a crucial role in achieving superlubricity, the long-standing challenge of achieving superlubricity in engineering has been attributed to surface roughness, which tends to destroy MSLs. Here, we show via molecular dynamics simulations that MSLs alone are not capable of capturing the friction behavior of a multilayer-graphene-coated substrate where similar MSLs persist in spite of significant changes in friction as the graphene coating thickness increases.

Quantitative tests revealing hydrogen-enhanced dislocation motion in α-iron.

Hydrogen embrittlement jeopardizes the use of high-strength steels in critical load-bearing applications. However, uncertainty regarding how hydrogen affects dislocation motion, owing to the lack of quantitative experimental evidence, hinders our understanding of hydrogen embrittlement. Here, by studying the well-controlled, cyclic, bow-out motions of individual screw dislocations in α-iron, we find that the critical stress for initiating dislocation motion in a 2 Pa electron-beam-excited H atmosphere is 27-43% lower than that in a vacuum environment, proving that hydrogen enhances screw dislocation motion.

Liquid-Phase Friction of Two-Dimensional Molybdenum Disulfide at the Atomic Scale.

Tribological properties depend strongly on environmental conditions such as temperature, humidity, and operation liquid. However, the origin of the liquid effect on friction remains largely unexplored. Herein, taking molybdenum disulfide (MoS) as a model system, we explored the nanoscale friction of MoS in polar (water) and nonpolar (dodecane) liquids through friction force microscopy.

One-Dimensional Strain Solitons Manipulated Superlubricity on Graphene Interface.

The frictional properties of a uniaxial tensile strained graphene interface are studied using molecular dynamics simulations. A misfit interval statistical method (MISM) is applied to characterize the atomistic misfits at the interface and strain soliton pattern. During sliding along both armchair and zigzag directions, the lateral force depends on the ratio of graphene flake length () to strain soliton spacing () and becomes nearly zero when is an integer multiple of 3.

Polyamine Oxidase Triggers HO-Mediated Spermidine Improved Oxidative Stress Tolerance of Tomato Seedlings Subjected to Saline-Alkaline Stress.

Saline-alkaline stress is one of several major abiotic stresses in crop production. Exogenous spermidine (Spd) can effectively increase tomato saline-alkaline stress resistance by relieving membrane lipid peroxidation damage. However, the mechanism through which exogenous Spd pre-treatment triggers the tomato antioxidant system to resist saline-alkaline stress remains unclear.

SHP2 inhibition enhances the anticancer effect of Osimertinib in EGFR T790M mutant lung adenocarcinoma by blocking CXCL8 loop mediated stemness.

Background: Additional epidermal growth factor receptor (EGFR) mutations confer the drug resistance to generations of EGFR targeted tyrosine kinase inhibitor (EGFR-TKI), posing a major challenge to developing effective treatment of lung adenocarcinoma (LUAD). The strategy of combining EGFR-TKI with other synergistic or sensitizing therapeutic agents are considered a promising approach in the era of precision medicine. Moreover, the role and mechanism of SHP2, which is involved in cell proliferation, cytokine production, stemness maintenance and drug resistance, has not been carefully explored in lung adenocarcinoma (LUAD).

Chronic alcohol exposure promotes HCC stemness and metastasis through -catenin/miR-22-3p/TET2 axis.

Hepatocellular Carcinoma (HCC) patients usually have a high rate of relapse and metastasis. Alcohol, a risk factor for HCC, promotes the aggressiveness of HCC. However, the basic mechanism is still unclear.

Unusual activated processes controlling dislocation motion in body-centered-cubic high-entropy alloys.

Atomistic simulations of dislocation mobility reveal that body-centered cubic (BCC) high-entropy alloys (HEAs) are distinctly different from traditional BCC metals. HEAs are concentrated solutions in which composition fluctuation is almost inevitable. The resultant inhomogeneities, while locally promoting kink nucleation on screw dislocations, trap them against propagation with an appreciable energy barrier, replacing kink nucleation as the rate-limiting mechanism.

Macroscale Superlubricity Enabled by Graphene-Coated Surfaces.

Friction and wear remain the primary modes for energy dissipation in moving mechanical components. Superlubricity is highly desirable for energy saving and environmental benefits. Macroscale superlubricity was previously performed under special environments or on curved nanoscale surfaces.

Temperature Effect on Stacking Fault Energy and Deformation Mechanisms in Titanium and Titanium-aluminium Alloy.

Alloying elements have great influence on mechanical properties of metals. Combining dislocation characterization and in-situ transmission electron microscope straining at ambient and liquid-nitrogen temperature in high-purity titanium and Ti-5at%Al, we investigated the modulation of Al on dislocation behaviours as temperature changed. It reveals that segregation of Al at edge dislocation cores in Ti-5at%Al generates strong obstacles, promoting room temperature cross-slips.

Ferroelectric switching in ferroelastic materials with rough surfaces.

Electric switching of non-polar bulk crystals is shown to occur when domain walls are polar in ferroelastic materials and when rough surfaces with steps on an atomic scale promote domain switching. All domains emerging from surface nuclei possess polar domain walls. The progression of domains is then driven by the interaction of the electric field with the polarity of domain boundaries.

Tuning friction to a superlubric state via in-plane straining.

Controlling, and in many cases minimizing, friction is a goal that has long been pursued in history. From the classic Amontons-Coulomb law to the recent nanoscale experiments, the steady-state friction is found to be an inherent property of a sliding interface, which typically cannot be altered on demand. In this work, we show that the friction on a graphene sheet can be tuned reversibly by simple mechanical straining.

Super-elastic ferroelectric single-crystal membrane with continuous electric dipole rotation.

Ferroelectrics are usually inflexible oxides that undergo brittle deformation. We synthesized freestanding single-crystalline ferroelectric barium titanate (BaTiO) membranes with a damage-free lifting-off process. Our BaTiO membranes can undergo a ~180° folding during an in situ bending test, demonstrating a super-elasticity and ultraflexibility.

GSTU43 gene involved in ALA-regulated redox homeostasis, to maintain coordinated chlorophyll synthesis of tomato at low temperature.

Background: Exogenous 5-aminolevulinic acid (ALA) positively regulates plants chlorophyll synthesis and protects them against environmental stresses, although the protection mechanism is not fully clear. Here, we explored the effects of ALA on chlorophyll synthesis in tomato plants, which are sensitive to low temperature. We also examined the roles of the glutathione S-transferase (GSTU43) gene, which is involved in ALA-induced tolerance to oxidation stress and regulation of chlorophyll synthesis under low temperature.

Utilizing the adaptive precursor [AsWO(HO)] to support three hexanuclear lanthanoid-based tungstoarsenate dimers.

Three tartrate-bridging lanthanide-based tungstoarsenate dimers K11H13[Ln3(H2O)8(OH)2(AsW9O33)(AsW10O35(C4O6H3))]2·nH2O (Ln3+ = Eu3+ (1Eu), n = 50; Tb3+ (2Tb), n = 34; C4O6H6 = tartaric acid) and K15H9[Dy3(H2O)15(OH)2(AsW9O33)(AsW10O35(C4O6H3))]2·21H2O (3Dy) have been synthesized and further characterized by elemental analyses, X-ray powder diffraction, IR spectra, thermogravimetric analyses and single-crystal X-ray diffraction. Structural analyses indicate that all the polyanions of 1Eu-3Dy are isostructural, and are composed of two identical asymmetric sandwiched subunits [Ln3(H2O)8(OH)2(AsW9O33)(AsW10O35(C4O6H3))]12- interlinked by two tartrate ligands. Furthermore, the photoluminescence and variable-temperature magnetic properties of 1Eu, 2Tb and 3Dy have also been investigated.

Lanthanide Functionalized Metal-Organic Coordination Polymer: Toward Novel Turn-On Fluorescent Sensing of Amyloid β-Peptide.

Metal-organic coordination polymers (MOCPs) have been emerging as very attractive nanomaterials due to their tunable nature and diverse applications. Herein, using Tb as the luminescence center, 1,3,5-benzenetricarboxylate (BTC) as building block and Cu as the signal modulator as well as a recognition unit, we propose a novel and effective lanthanide functionalized MOCP (LMOCP) fluorescent sensor (Cu-BTC/Tb) for amyloid β-peptide (Aβ) monomer, a biomarker for Alzheimer disease (AD). Specifically, Cu-BTC/Tb, created by postsynthesis modification strategy under room temperature, is almost nonemissive due to the quenching effect of Cu in the MOCP, exhilaratingly, the presence of Aβ triggered a significant emission enhancement of Cu-BTC/Tb assay due to the high binding affinity of Aβ for Cu and the subsequent suppression of the quenching effect.

Four one-dimensional lanthanide-phenylacetate polymers exhibiting luminescence and magnetic cooling/spin-glass behavior.

Four isostructural lanthanide coordination polymers with a phenylacetate (PAA) ligand, [Ln(PAA)(HO)] (Ln = Eu (1); Gd (2); Tb (3); Dy (4)), were synthesized under hydrothermal conditions. Complexes 1-4 display a one-dimensional (1D) wave chain structure bridged by the carboxylate of the PAA ligand, which was generated via the in situ decarboxylation of phenylmalonic acid. Magnetic studies suggest the presence of ferromagnetic LnLn coupling in the 1D chain of 1-4.

Statistics of twinning in strained ferroelastics.

In this review, we show that the evolution of the microstructure and kinetics of ferroelastic crystals under external shear can be explored by computer simulations of 2D model materials. We find that the nucleation and propagation of twin boundaries in ferroelastics depend sensitively on temperature. In the plastic regime, the evolution of the ferroelastic microstructure under strain deformation maintains a stick-and-slip mechanism in all temperature regimes, whereas the dynamic behavior changes dramatically from power-law statistics at low temperature to a Kohlrausch law at intermediate temperature, and then to a Vogel-Fulcher law at high temperature.

Genome-wide association study of high-altitude pulmonary edema in a Han Chinese population.

A two-stage genome-wide association study (GWAS) was performed to identify and analyze genes and single nucleotide polymorphisms (SNPs) associated with high-altitude pulmonary edema (HAPE) in a Han Chinese patient population. In the first stage, DNA samples from 68 patients with recurrent HAPE were scanned using Affymetrix SNP Array 6.0 Chips, and allele frequencies were compared to those of 84 HapMap CHB samples to identify candidate SNPs.

Syntheses, Photoluminescence, and Electroluminescence of a Series of Sublimable Bipolar Cationic Cuprous Complexes with Thermally Activated Delayed Fluorescence.

Three thermally activated delayed fluorescence cationic cuprous complexes [Cu(POP) (ECAF)]PF (1, POP = bis(2-diphenylphosphinophenyl)ether, ECAF = 9,9-bis(9-ethylcarbazol-3-yl)-4,5-diazafluorene), [Cu(POP) (EHCAF)]PF (2, EHCAF = 9,9-bis(9-ethylhexylcarbazol-3-yl)-4,5-diazafluorene), and [Cu(POP) (PCAF)]PF (3, PCAF = 9,9-bis(9-phenylcarbazaol-3-yl)-4,5-diazafluorene) with bipolar 4,5-diazafluorene ligand substituted by bis-carbazole have been successfully prepared, and their UV absorption, photoluminescent properties, and electrochemical behaviors were investigated. At room temperature, complexes 1, 2, and 3 exhibit efficient yellowish-green emission with peak maxima of 550, 549, and 556 nm, respectively, and lifetimes of 5.7 μs.