807 research outputs found
Triaqua(2,2′-bipyridine)(5-nitroisophthalato-κO)nickel(II) monohydrate
In the title compound, [Ni(C8H3NO6)(C10H8N2)(H2O)3]·H2O, the NiII cation is six-coordinated by a chelating 2,2′-bipyridine ligand, one carboxylate O atom from a 5-nitroisophthalate dianion and three water molecules, with a slightly distorted cis-NiN2O4 octahedral geometry. The neutral complex is isolated, in contrast to coordination polymers formed by MnII, CoII and CuII with the same ligand set, but forms an extensive network of O—H⋯O hydrogen bonds between the coordinated and uncoordinated water molecules and carboxylate groups of the 5-nitroisophthalate ions
Changes and mechanisms of apparent resistivity before earthquakes of MS6.0–6.9 on the Chinese mainland
China has been conducting fixed continuous apparent resistivity observations since 1967. Up to June 2022, 45 earthquakes with magnitudes of MS6.0–6.9 have occurred within a range of approximately 250 km from normal operating stations. Through literature investigation and data analysis, monitoring stations counted 61 short-medium-term apparent resistivity anomalous changes (i.e., 44 decrease changes, 15 increase changes, and 2 perturbance changes) appearing before 39 of these earthquakes. In this study, we utilize a fault virtual dislocation model to understand the relative deformations around the epicenters before these earthquakes. The comparison results showed that 36 of the 44 decrease changes were in areas with compression enhancement and that 9 of the 15 increase changes were in areas with relative dilatancy. The results from rock petrophysical experiments and the resistivity model of the cracked medium showed decreased changes in the resistivity of water-bearing geomaterials during the successive loading of compressive stress, while the resistivity showed increased changes during the stress unloading process. Moreover, 45 of the 61 apparent resistivity anomalies were consistent with the mechanism of resistivity change under stress. These apparent resistivity anomalous changes before earthquakes may be related to the seismogenic processes such that the resistivity change is caused by medium deformation
Higher-Order Nonlinear Anomalous Hall Effects Induced by Berry Curvature Multipoles
In recent years, it has been shown that Berry curvature monopoles and dipoles
play essential roles in the anomalous Hall effect and the nonlinear Hall effect
respectively. In this work, we demonstrate that Berry curvature multipoles (the
higher moments of Berry curvatures at the Fermi energy) can induce higher-order
nonlinear anomalous Hall (NLAH) effect. Specifically, an AC Hall voltage
perpendicular to the current direction emerges, where the frequency is an
integer multiple of the frequency of the applied current. Importantly, by
analyzing the symmetry properties of all the 3D and 2D magnetic point groups,
we note that the quadrupole, hexapole and even higher Berry curvature moments
can cause the leading-order frequency multiplication in certain materials. To
provide concrete examples, we point out that the third-order NLAH voltage can
be the leading-order Hall response in certain antiferromagnets due to Berry
curvature quadrupoles, and the fourth-order NLAH voltage can be the leading
response in the surface states of topological insulators induced by Berry
curvature hexapoles. Our results are established by symmetry analysis,
effective Hamiltonian and first-principles calculations. Other materials which
support the higher-order NLAH effect are further proposed, including 2D
antiferromagnets and ferromagnets, Weyl semimetals and twisted bilayer graphene
near the quantum anomalous Hall phase.Comment: 17 pages, 5 figure
Transcriptomic analysis of the response of Avena sativa to Bacillus amyloliquefaciens DGL1
IntroductionBacillus amyloliquefaciens DGL1, isolated from the arid sandy areas in Dagler, Qinghai Province, China, promotes the growth of Avena sativa variety “Qing Yan 1”.MethodsTo elucidate the transcriptomic changes in the oat root system following interaction with DGL1 and to reveal the molecular mechanism by which DGL1 promotes oat growth, treatment and control groups of oat roots at 2, 4, 8, and 12 h after inoculation with a suspension of strain DGL1 were analyzed using Illumina high-throughput transcriptome sequencing technology. The differentially expressed genes were determined through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, and the metabolic pathways and key genes were analyzed.ResultsThe results showed that 7874, 13,392, 13,169, and 19,026 differentially expressed genes were significantly enriched in the glycolysis/gluconeogenesis pathway, amino acid metabolism, nitrogen metabolism, plant hormone signal transduction, and other related metabolic pathways in the oat roots at 2, 4, 8, and 12 h after inoculation with a DGL1 suspension. The GO and KEGG enrichment analyses revealed that the genes encoding plasma membrane ATPase, phosphoglycerate kinase gene PGK, ammonium transporter protein gene AMT, cellulose synthase gene CSLF6, and growth hormone response family gene IAA18 were significantly upregulated.DiscussionIt is hypothesized that the pro-growth mechanism of strain DGL1 in oats is the result of the coordination of multiple pathways through the promotion of oat energy metabolism, phytohormone signaling, secondary metabolite synthesis, and amino acid metabolism
Analysis of intravitreal injection of triamcinolone acetonide before vitrectomy for retinal detachment associated with choroidal detachment
AIM:To observe the clinical effects of intravitreal injection of triamcinolone acetonide(TA)before vitrectomy for retinal detachment associated with choroidal detachment.METHODS: Totally 23 cases(23 eyes)of retinal detachment associated with choroidal detachment in our hospital were treated by intravitreal injection of TA 4-5d before 23-Gauge micro-invasive vitrectomy combined with silicone oil injection. All the cases were followed up between 6 to 9mo. The anatomic retinal reattachment, visual acuity, intraocular pressure and postoperative complications were observed and analyzed. RESULTS: After the surgery, the visual acuity of all patients were improved, with 9 eyes better than 0.3(39%), and 18 eyes better than 0.05(78%). The BCVA at 1wk, 1 and 3mo and last follow up were different compared with before operations(PPPCONCLUSION: Intravitreal injection of TA before vitrectomy for retinal detachment associated with choroidal could improve the clinical effects, and decrease the difficulty of surgery while the injection itself is pretty safe
Drought stress tolerance and metabolomics of Medicago sativa induced by Bacillus amyloliquefaciens DGL1
IntroductionThis study used Bacillus amyloliquefaciens DGL1 isolated from the arid sandy land of the Qinghai–Tibetan Plateau as the research strain and investigated the effects of DGL1 on the biomass, physiology, and metabolites of Medicago sativa under different intensities of drought stress to provide a high-quality bacterial source and a theoretical basis for the research and development of biological fertilizer suitable for arid areas.MethodsThe exopolysaccharides (EPS), 1-Aminocyclopropane-1-carboxylate deaminase (ACC), and phosphorus solubilizing capacity of DGL1 were determined. The effects of a DGL1 suspension on alfalfa biomass, physiological indexes, degree of peroxidation of cell membranes, and activity of antioxidant enzymes were determined after irrigating roots under drought stress. The effects on soil physicochemical properties were also evaluated, and metabolomics analysis was performed to explore the effect of DGL1 on the metabolites of alfalfa under drought stress.ResultsStrain DGL1 produced extracellular polysaccharide EPS and ACC deaminase and was capable of phosphorus solubilization. Treatment with DGL1 increased the biomass of alfalfa under different degrees of drought stress, significantly increased the activities of alfalfa antioxidant enzymes Super Oxide Dismutase (SOD), Peroxidase (POD), and catalase (CAT), reduced the content of MDA and H2O2, and increased the content of quick-acting phosphorus, quick-acting potassium, ammonium nitrogen, and nitrate nitrogen in the soil, thus improving soil fertility. Through metabolomics analysis, DGL1 was shown to affect amino acid metabolic pathways, such as arginine, leucine, glutamate, and tyrosine, as well as the levels of energy-providing polysaccharides and lipids, in alfalfa under 15% PEG-6000 drought stress, enhancing alfalfa’s capacity to resist drought stress.DiscussionStrain DGL1 enhances the drought suitability of alfalfa and has the potential for dryland development as a biological agent
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