Probing resistive switching in HfO2/Al2O3 bilayer oxides using in-situ transmission electron microscopy

In this work, we investigate the resistive switching in hafnium dioxide (HfO2) and aluminum oxide (Al2O3) bilayered stacks using in-situ transmission electron microscopy and X-ray energy dispersive spectroscopy. Conductance of the HfO2/Al2O3 stack changes gradually upon electrical stressing which is related to the formation of extended nanoscale physical defects at the HfO2/Al2O3 interface and the migration and re-crystallization of Al into the oxide bulk. The results suggest two competing physical mechanisms including the redistribution of oxygen ions and the migration of Al species from the Al electrode during the switching process. While the HfO2/Al2O3 bilayered stack appears to be a good candidate for RRAM technology, the low diffusion barrier of the active Al electrode causes severe Al migration in the bi-layered oxides leading to the device to fail in resetting, and thereby, largely limiting the overall switching performance and material reliability

CMTM4 Inhibits Gastric Tumorigenesis and Metastasis

BACKGROUND: CKLF-like MARVEL transmembrane domain-containing 4 (CMTM4) is involved in immune regulation and tumor progression; however, its role in gastric cancer (GC) remains unclear. This study explored the role and mechanism of CMTM4 in GC. METHODS: Immunohistochemistry was used to analyze CMTM4 expression in human gastric biopsied cells from patients with GC (N=23) or chronic superficial gastritis (N=23). To investigate the function of CMTM4 in GC cells, the gene RESULTS: CMTM4 expression was more downregulated in the human GC tissues than the gastritis tissues. CMTM4 overexpression significantly inhibited the proliferation, migration, and invasion of the GC cells, whereas CMTM4 knockdown enhanced gastric cell proliferation (P\u3e0.05), migration (P\u3e0.05), and invasion (P\u3e0.05). Flow cytometry showed that CMTM4 promoted apoptosis and resulted in G1/S arrest in the GC cells. In addition, the proteome and western blot results showed that STAT1 was significantly upregulated, and the STAT1 signaling pathways were enriched in the GC cells overexpressing CMTM4. CONCLUSIONS: Our results suggest that CMTM4 plays a tumor-suppressive role in GC and may affect the growth, migration, and invasion of GC cells through the STAT1 signaling pathway. CMTM4 might have potential value as a prognosis marker and potential therapeutic target for GC therapy

Exploring the prevalence and chest CT predictors of Long COVID in children: a comprehensive study from Shanghai and Linyi

IntroductionCOVID-19 constitutes a pandemic of significant detriment to human health. This study aimed to investigate the prevalence of Long COVID following SARS-CoV-2 infection, analyze the potential predictors of chest CT for the development of Long COVID in children.MethodsA cohort of children who visited the respiratory outpatient clinics at Shanghai Children's Medical Center or Linyi Maternal and Child Health Care Hospital from December 2022 to February 2023 and underwent chest CT scans within 1 week was followed up. Data on clinical characteristics, Long COVID symptoms, and chest CT manifestations were collected and analyzed. Multivariate logistic regression models and decision tree models were employed to identify factors associated with Long COVID.ResultsA total of 416 children were included in the study. Among 277 children who completed the follow-up, the prevalence of Long COVID was 23.1%. Chronic cough, fatigue, brain fog, and post-exertional malaise were the most commonly reported symptoms. In the decision tree model for Long COVID, the presence of increased vascular markings, the absence of normal CT findings, and younger age were identified as predictors associated with a higher likelihood of developing Long COVID in children. However, no significant correlation was found between chest CT abnormality and the occurrence of Long COVID.DiscussionLong COVID in children presents a complex challenge with a significant prevalence rate of 23.1%. Chest CT scans of children post-SARS-CoV-2 infection, identified as abnormal with increased vascular markings, indicate a higher risk of developing Long COVID

EIGENVALUE ESTIMATES FOR QUADRATIC POLYNOMIAL OPERATOR OF THE LAPLACIAN

AbstractFor a bounded domain Ω in a complete Riemannian manifold M, we investigate the Dirichlet weighted eigenvalue problem of quadratic polynomial operator Δ2 − aΔ + b of the Laplacian Δ, where a and b are the nonnegative constants. We obtain an inequality for eigenvalues which contains a constant that only depends on the mean curvature of M. It yields an upper bound of the (k + 1)th eigenvalue Λk + 1. As their applications, some inequalities and bounds of eigenvalues on a complete minimal submanifold in a Euclidean space and a unit sphere are obtained.</jats:p