Prediction of erbium-nitrogen compounds as high-performance high-energy-density materials.

To explore high-energy-density materials, intense attention has been focused on how to stabilize the N-N bond in nitrogen-rich compounds. Here, we report several stable phases of erbium-nitrogen compounds ErNxas high-energy-density materials. Specifically, the phase diagrams of stable high-pressure structuresImmm-ErN2,C2-ErN3,P1--ErN4, andP1--ErN6, are theoretically studied by combining first-principles calculation with particle swarm optimization algorithm. In these erbium-nitrogen compounds, the N-N bonds are stabilized as diatomic quasi-molecule N2, helical-like nitrogen chains, armchair nitrogen chains, and armchair-anti-armchair nitrogen chains, respectively. Among them, theP1--ErN6harbors excellent stability at high thermal up to 1000 K. More importantly, theP1--ErN6has outstanding explosive performance with high-energy-density of 1.30 kJ g-1, detonation velocity of 10.87 km s-1, and detonation pressure of 812.98 kbar, which shows its promising application prospect as high-energy-density materials.

Postoperative adverse cardiac events in acute myocardial infarction with high thrombus load and best time for stent implantation.

BACKGROUND: Myocardial infarction is one of the most common types of coronary heart disease. It is mainly caused by the rupture of coronary atherosclerotic plaque, which leads to platelet agglutination and thrombosis. The occlusion of coronary arteries and vessels leads to insufficient myocardial blood supply, subsequently causing cardiac interstitial fibrosis, gradual enlargement of ventricles, and heart failure, which affects the quality of life and safety of patients. AIM: To investigate the effects of emergency percutaneous interventional therapy (PCI) and delayed stenting in acute myocardial infarction with high thrombotic load and identify factors related to major adverse cardiovascular events (MACE). METHODS: A total of 164 patients with acute myocardial infarction and high thrombotic load who received PCI were included. Of them, 92 patients were treated with delayed stent implantation (delayed group) and 72 patients received emergency PCI (immediate group). Myocardial perfusion after stent implantation was compared between the two groups. Patients were followed up for 12 mo, and the occurrence of MACE was used as the endpoint. Univariate and multivariate models were used to analyze the factors affecting MACE occurrence. RESULTS: After stent implantation, 66 (71.74%) patients in the delayed group and 40 (55.56%) patients in the immediate group had thrombolysis in myocardial infarction (TIMI) flow grade 3 (P < 0.05), while 61 (66.30%) patients in the delayed group and 39 (54.17%) patients in the immediate group reached TIMI myocardial perfusion grade 3 (P > 0.05). MACE occurred in 29 patients. There were statistically significant differences between the MACE and non-MACE groups in diabetes rate, TIMI grading, stent implantation timing, intraoperative use of tirofiban, and the levels of white blood cells (WBC), neutrophils, red blood cell distribution width (RDW), and uric acid, and high-sensitivity C-reactive protein (hs-CRP) at admission (P < 0.05). Logistic regression analysis showed that TIMI grade 3 and intraoperative use of tirofiban effectively reduced the risk of MACE (P < 0.05), while immediate stent implantation, increased WBC, hs-CRP and RDW on admission increased the risk of MACE (P < 0.05). CONCLUSION: Delayed stent implantation outweighs emergency PCI in improving postoperative myocardial perfusion in acute myocardial infarction with high thrombotic load, and effectively reduces MACE in these patients.

Toward a General Understanding of Exciton Self-Trapping in Metal Halide Perovskites.

Self-trapped excitons (STEs) have recently been observed in several metal halide perovskites (MHPs), especially in low-dimensional ones. Despite studies that have shown that factors like dopant, chemical composition, lattice distortion, and structural and electronic dimensionality may all affect the self-trapping of excitons, a general understanding of their mechanism of formation in MHPs is lacking. Here, we study the intrinsic and defect-induced self-trapping of excitons in three-, two-, and one-dimensional MHPs. We find that whether the free excitons could be trapped is simply determined by the competition of the energy-gap decrease and deformation-energy increase along with the lattice distortion. Both introducing halogen defects into the lattice and decreasing the dimensionality can tip the balance between them and thus facilitate the self-trapping of free excitons. This general picture of the mechanism of formation of STEs provides important insights into the design and development of high-performance white-light devices and solar cells with MHPs.