Strain mediated phase crossover in Ruddlesden Popper nickelates

Recent progress on the signatures of pressure-induced high temperature superconductivity in Ruddlesden Popper (RP) nickelates (Lan+1NinO3n+1) has attracted growing interest in both theoretical calculations and experimental efforts. The fabrication of high-quality single crystalline RP nickelate thin films is critical for possible reducing the superconducting transition pressure and advancing applications in microelectronics in the future. In this study, we report the observations of an active phase transition in RP nickelate films induced by misfit strain. We found that RP nickelate films favor the perovskite structure (n = infinite) under tensile strains, while compressive strains stabilize the La3Ni2O7 (n = 2) phase. The selection of distinct phases is governed by the strain dependent formation energy and electronic configuration. In compressively strained La3Ni2O7, we experimentally determined splitting energy is ~0.2 eV and electrons prefer to occupy in-plane orbitals. First principles calculations unveil a robust coupling between strain effects and the valence state of Ni ions in RP nickelates, suggesting a dual driving force for the inevitable phase co-existence transition in RP nickelates. Our work underscores the sensitivity of RP nickelate formation to epitaxial strain, presenting a significant challenge in fabricating pure-phase RP nickelate films. Therefore, special attention to stacking defects and grain boundaries between different RP phases is essential when discussing the pressure-induced superconductivity in RP nickelates.Comment: 29 pages, 5 figures, one supplementary material

Comparison of postoperative complications in mediastinal lymph node dissection versus mediastinal lymph node sampling for early stage non-small cell lung cancer: Protocol for a systematic review and meta-analysis.

IntroductionLung cancer is the primary cause of cancer-related deaths worldwide, with high rates of morbidity and mortality. The most effective treatment for early stage (I-II) non-small cell lung cancer (NSCLC) is surgical resection. However, the extent of mediastinal lymph nodes removal required and the impact of their removal remains controversial. This systematic review and meta-analysis aimed to evaluate the postoperative complications in patients with stage I-II NSCLC who received mediastinal lymph node dissection (MLND) or mediastinal lymph node sampling (MLNS).Methods and analysisAccording to the predefined inclusion criteria, we will conduct a comprehensive search for randomized controlled trials (RCTs) and observational studies examining the postoperative complications of MLND compared to MLNS in patients with stage I-II NSCLC. The search will be performed across multiple databases including PubMed, Embase, the Cochrane Library, CNKI, WanFang, Sinomed, VIP, Duxiu, and Web of Science from inception to February 2024. Additionally, relevant literature references will be retrieved and hand searching of pertinent journals will be conducted. Screening, data extraction, and quality assessment will be performed by two independent reviewers. Review Manager 5.4 will be applied in analyzing and synthesizing. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) will be used to assess the quality of evidence for the whole RCTs and used Newcastle-Ottawa scale to assess the methodologic quality of observational studies.Ethics and disseminationThis study did not include personal information. Ethical approval was not required for this study. This study is based on a secondary analysis of the literature, so ethical review approval is not required. The final report will be published in a peer-reviewed journal.ConclusionThis systematic review will contribute to compare the safety and survival benefits of these two surgical techniques for the treatment of early stage NSCLC, to further guide the selection of surgical approaches.Trial registrationThe protocol of the systematic review has been registered on Open Science Framework, with a registration number of DOI https://doi.org/10.17605/OSF.IO/N2Y5D

Perceived effectiveness of public health measures and positive attitudes during a pandemic: a large cross-sectional study in Shanghai, China

Objectives Building individuals’ positive attitudes during a pandemic is essential for facilitating psychological resilience. However, little is known about how public health measures may improve people’s positive attitudes during a pandemic. We investigated the potential mechanism underlying the association between individuals’ perceived effectiveness of public health measures and positive attitudes towards the success of pandemic control during the COVID-19 pandemic, by examining the parallel mediating effects of three types of threat appraisals: concerns about contracting the virus, perceived impact of the pandemic on life and estimated duration of the pandemic.Design, setting and participants In February 2020 when the COVID-19 infection was spreading rapidly in China, a large cross-sectional survey was conducted among 132 054 adults from the 16 districts in Shanghai, China.Outcome measures Perceived effectiveness of the public health measures, positive attitudes towards the success of pandemic control and threat appraisals.Results Results of structural equation modelling supported the hypothesised mediation model: perceived effectiveness of public health measures was associated with lower levels of concerns about contracting the virus (β=−0.20), perceived impact of the pandemic (β=−0.13) and perceived duration of the pandemic (β=−0.20), which were then associated with higher levels of positive attitudes towards the success of pandemic control (βs=−0.12 to −0.25).Conclusions The findings suggest that threat appraisals may be important pathways through which individuals’ evaluations of prevention strategies may influence their attitudes towards the success of pandemic control. The health authorities should consider reducing people’s inappropriate threat appraisals when designing public health policies to facilitate people’s positive attitudes during a pandemic

Simulation Optimization and Application of Shearer Strapdown Inertial Navigation System Modulation Scheme

The operating attitude of a shearer based on a three-dimensional (3D) space scale is the necessary basic information for realizing intelligent mining. Aiming to address the problem of the insufficient perception accuracy of shearers, in this paper, the rotation model of the actual turning mechanism of the strapdown inertial navigation system (SINS) of shearers is established, and the error propagation characteristics of different single-axis rotation modulation schemes are revealed. Through theory and simulation, the optimal rotation modulation scheme is determined to be the improved four-position turn–stop modulation with a rotation of <360°. The experiment shows that the 24 h positioning error of this scheme is 3.7 nmile, and the heading angle changes by 0.06°, which proves that this scheme can effectively improve the attitude perception accuracy of the inertial navigation system (INS). The field application of the shearer operating attitude perception based on this scheme shows that the positioning error after error compensation is 17% of that before compensation, and the heading angle error is 75% of that before compensation, which verifies that this scheme can significantly improve the accuracy of shearer operating attitude perception in field applications. This scheme can achieve higher precision perception accuracy based on SINS and has broad application prospects in the field of high-precision pose perception of coal mining machines, roadheaders, and other equipment