A series of lanthanide-based organic frameworks with formulas of {[PrL(H2O)2]·2H2O}n (1) and {[Ln3L3(H2O)2]·2H2O}n (Ln = Eu (2), Gd (3), Tb (4), Dy (5), Ho (6), Er (7); H3L = 4-(carboxymethoxy)isophthalic acid), were hydrothermally synthesized and structurally characterized. It is the first time that 4-(carboxymethoxy)isophthalic acid is employed in producing lanthanide compounds. The seven compounds exhibit two types of structures with the decreasing radius of the lanthanide ions, representing the lanthanide contraction effect. Compound 1 with the large Pr3+ ion displays a 2D layered structure with a binodal (4,4)-connected topology with the Schläfli symbol of (3363)2, whereas compounds 2–7 with small Ln3+ ions feature a 3D framework constructed from carboxyl groups with a (5,6,8)-connected topology with the Schläfli symbol of (324454)·(34445463)·(344856698). The luminescence and magnetic properties were investigated, and the results indicate that the H3L ligand can sensitize the lanthanide luminescence in compounds 2, 4 and 5 and makes a contribution to the antiferromagnetic interactions in compound 3 or the uncertain magnetic interactions in compounds 4–7. Additionally, the thermal analyses suggest the high thermal stability of compounds 1–7.
The production of low-stress, high-performance wear-resistant steels poses a formidable challenge in the steel industry. This article delves into the carbide precipitation behaviour of wear-resistant steel NM300TP during tempering and its subsequent impact on residual stress and mechanical properties. Our findings reveal a crucial aspect: prolonging the holding time can interfere with the precipitation behaviour of carbides, thereby altering the relaxation mechanism of residual stress and its influence on material properties. Remarkably, we discovered that substituting the formation of θ-cementites with the precipitation of ε-transition carbides can yield a steel with significantly lower residual stress while maintaining exceptional mechanical properties. Specifically, when θ-cementites precipitate, the residual stress in the wear-resistant steel diminishes by 54.23%, accompanied by a hardness measurement of 299.58 HV 0.5. However, when a substantial quantity of ε-transition carbides is dispersed and precipitated, the residual stress is further diminished by 69.51%, and the hardness reaches 317.2 HV 0.5. Furthermore, this precipitation of ε-transition carbides exhibits superior wear resistance compared to θ-cementites. These groundbreaking discoveries offer critical theoretical insights for the development of low-stress, high-performance wear-resistant steels, paving the way for innovative advancements in the steel industry.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract The spin polarization of carbon nanomaterials is crucial to design spintronic devices. In this paper, the first‐principles is used to study the electronic properties of two defect asymmetric structures, Cap‐(9, 0)‐Def [6, 6] and Cap‐(9, 0)‐Def [5, 6]. We found that the ground state of Cap‐(9, 0)‐Def [6, 6] is sextet and the ground state of Cap‐(9, 0)‐Def [5, 6] is quartet, and the former has a lower energy. In addition, compared with Cap‐(9, 0) CNTs, the C adatom on C 30 causes spin polarization phenomenon and Cap‐(9, 0)‐Def [6, 6] has more spin electrons than Cap‐(9, 0)‐Def [5, 6] structure. Moreover, different adsorb defects reveal different electron accumulation. This finding shows that spin polarization of the asymmetric structure can be adjusted by introducing adatom defects.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Background Previous studies have indicated a potential relationship between zinc and epilepsy. The aim of this study is to investigate the causal relationship between zinc, zinc-dependent carbonic anhydrase, and gray matter volume in brain regions enriched with zinc, in relation to epileptic seizures, as well as explore the possible mechanisms by which zinc contributes to epilepsy. Methods First, this study assessed the risk causality between zinc, carbonic anhydrase, and gray matter volume alterations in zinc-enriched brain regions and various subtypes of epilepsy based on two-sample Mendelian randomization analysis. And then, Then, this study conducted GO/KEGG analysis based on colocalization analysis, MAGMA analysis, lasso regression, random forest model and xgboot model. Results 1. There was a causal relationship between zinc, carbonic anhydrase-4, and generalized epilepsy (p = 0.044, p = 0.010). Additionally, carbonic anhydrase-1 and gray matter volume of the caudate nucleus were found to be associated with epilepsy and focal epilepsy (p = 0.014, p = 0.003, p = 0.022, p = 0.009).2. A colocalization relationship was found between epilepsy and focal epilepsy (PP.H4.abf = 97.7e-2). MAGMA analysis indicated that SNPs associated with epilepsy and focal epilepsy were functionally localized to zinc-finger-protein-related genes (p < 1.0e-5).3. The genes associated with focal epilepsy were found to have a molecular function of zinc ion binding (FDR = 1.9e-4). Within 4 to 24 hours after experiencing epilepsy, the function of the gene whose expression changed in the rats with focal epilepsy was enriched in the biological process of vascular response (FDR = 4.0e-5), compared to the rats without seizure. Conclusion The mechanism of the increased risk of epilepsy caused by zinc may be related to the increase of zinc ion-dependent carbonic anhydrase or the increase of the volume of zinc-rich caudate gray matter.
Nanocrystalline La 2 Sn 2 O 7 and La 2 Sn 1.8 Co 0.2 O 7 with a phase‐pure pyrochlore structure were synthesized by a hydrothermal method, and their catalytic activity was investigated for soot combustion. The as‐synthesized catalysts presented relatively larger surface area, and pore volume, which was benefit to the gas molecule diffusion in the reaction. A uniform spherical structure with particle size of 200–500 nm was found in SEM. The samples via hydrothermal route are more active for catalytic soot combustion, ascribing to the spherical morphology, high surface area and improved oxygen mobility. After Co, the reducibility was improved and surface oxygen vacancy was produced, resulting in the enhanced activity and selectivity to CO 2 formation.
Toll-like receptor 4 (TLR4) signal activation of macrophages can lead to endotoxin-induced uveitis (EIU). Previously, our research group has demonstrated a higher expression of TLR4 in vivo during EIU than normal. In this study, we analyzed levels of peritoneal macrophage cytokines from C3H/HeN mice with LPS stimulation in vitro to elucidate the effect of TLR4 on cytokines during EIU.
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