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Abstract Background Optimization of risk stratification is important for facilitating prognoses and therapeutic decisions regarding diffuse large B‐cell lymphoma (DLBCL). However, a simple and applicable prognostic tool is lacking for individuals with human immunodeficiency virus (HIV)‐related DLBCL in the era of combined antiretroviral therapy (cART). Methods This retrospective multicenter observational study included 147 HIV‐related DLBCL patients with histologically confirmed DLBCL from 2013 to 2020. The total group was divided into training (n = 78) and validation (n = 69) cohorts to derive the best prognostic score. Clinicopathological and characteristic biomarkers correlated with clinical outcomes were analyzed. Results Age, Ann Arbor stage, lactate dehydrogenase (LDH) ratio, bulky disease, and red blood cell distribution width (RDW) ratio retained robust independent correlations with overall survival (OS) in multivariate analysis. A new and practical prognostic model was generated and externally validated, classifying patients into three categories with significantly different survival rates. Moreover, the new index outperformed the International Prognostic Index (IPI) score (area under the curve values of 0.94 vs. 0.81 in the training cohort and 0.85 vs. 0.74 in the validation cohort, C‐indices of 0.80 vs. 0.70 in the training cohort and 0.74 vs. 0.70 in the validation cohort, and integrated discrimination improvement values of 0.203 in the training cohort and 0.175 in the validation cohort) and was better at defining intermediate‐ and high‐risk groups. The calibration curves performed satisfactorily for predicting 3‐year OS in the training and validation cohorts. Conclusions We developed and validated a simple and feasible prognostic model for patients with HIV‐related DLBCL that had more discriminative and predictive accuracy than the IPI score for risk stratification and individualized treatment in the cART era.

Abstract Electromagnetic ion cyclotron (EMIC) waves are known to exhibit frequency chirping occasionally, contributing to the rapid acceleration and precipitation of energetic particles in the magnetosphere. However, the chirping mechanism of EMIC waves remains elusive. In this work, a phenomenological model of whistler mode chorus waves named the Trap‐Release‐Amplify (TaRA) model is applied to EMIC waves. Based on the proposed model, we explain how the chirping of EMIC waves occurs, and give predictions on their frequency chirping rates. For the first time, we relate the frequency chirping rate of EMIC waves to both the wave amplitude and the background magnetic field inhomogeneity. Direct observational evidence is provided to validate the model using previously published events of chirping EMIC waves. Our results not only provide a new model for EMIC wave frequency chirping, but more importantly, they indicate the potential wide applicability of the underlying principles of TaRA model.

Abstract Whistler mode chorus waves frequently appear as discrete, repetitive, and quasi‐monochromatic emissions with frequency chirping. With different wave amplitude and frequency chirping rate, chorus waves have been observed not only in the magnetosphere of the Earth but also in the magnetospheres of other planets, such as Saturn and Jupiter. Motivated by understanding different properties of chorus waves at these planets using the recently proposed “Trap‐Release‐Amplify” (TaRA) model, we perform a parametric study using Particle‐In‐Cell simulations by varying background magnetic field inhomogeneity and the corresponding threshold hot electron number density. We show the consistency between simulation results and theoretical predictions for threshold hot electron number density, chorus chirping rate, and wave amplitude. Our results suggest the significant role of the background magnetic field inhomogeneity in affecting chorus wave properties, including its amplitude at different planets as predicted by the TaRA model.

Abstract Chorus waves are electromagnetic emissions in the magnetosphere and play a crucial role in energetic electron dynamics. Observations show that these waves often exhibit a two‐band structure with a power gap near half the electron cyclotron frequency. However, the mechanism behind this gap remains an open question, despite the existence of multiple theories. Here we propose a model to explain the banded structure by the different propagation properties of the lower and upper band waves within a density crest. This requires independent sources for lower and upper band waves, and unducted propagation of upper band waves to the observing location. The model naturally generates a gap near half the electron cyclotron frequency and can be extended to explain lower‐band‐only, upper‐band‐only, and no‐gap whistler waves. The model calls for further research on density irregularities in the magnetosphere and their effects on shaping wave properties.

Abstract Introduction Long noncoding RNA Mirt2 has been proven to be a suppressor of lipopolysaccharide (LPS) (a key player in sepsis)‐induced inflammation responses. Therefore, Mirt2 may also participate in sepsis. This study was carried out to analyze the interactions between Mirt2 and microRNA‐1246 (miR‐1246) in sepsis, with a specific focus on sepsis‐induced acute lung injury (sepsis‐ALI). Methods Forty sepsis patients (sepsis group; 23 males and 17 females; 40–65 years, 48.6 ± 6.3 years), 40 sepsis patients with acute lung injury (sepsis‐ALI group, 23 males and 17 females; 40–65 years, 48.7 ± 6.4 years), and 40 healthy controls (control group, 23 males and 17 females; 40–65 years, 48.6 ± 6.1 years) were included. Mirt2 and miR‐1246 expression in plasma samples from these patients were determined by a reverse transcription‐quantitative polymerase chain reaction (PCR). Overexpression of Mirt2 and miR‐1246 was achieved in human bronchial epithelial cells (HBEpCs) to explore the interaction between them. The effects of Mirt2 overexpression on miR‐1246 methylation were analyzed by methylation‐specific PCR. Cell apoptosis analysis was performed to analyze the role of Mirt2 and miR‐1246 in the apoptosis of HBEpCs. Results Mirt2 expression was downregulated in sepsis and was further downregulated in patients with sepsis‐ALI. Mirt2 and miR‐1246 found to be positively correlated. Downregulation of Mirt2 and miR‐1246 was observed in HBEpCs with LPS treatment. In HBEpCs, Mirt2 overexpression increased miR‐1246 expression but decreased its gene methylation. Cell apoptosis analysis showed that Mirt2 and miR‐1246 negatively regulated the apoptosis of HBEpCs induced by LPS. In addition, miR‐1246 inhibition reduced the inhibitory effects of Mirt2 overexpression on cell apoptosis. Conclusions Mirt2 may upregulate miR‐1246 through methylation to suppress lung cell apoptosis.

Abstract Whistler mode chorus, characterized by frequency chirping, is an important type of waves in planetary magnetospheres. To investigate the role of nonlinear wave particle interactions in excitation of chorus, analysis of electron phase space dynamics is required. While electron phase hole associated with rising tone chorus has been well studied, the phase space structure corresponding to falling tone chorus is less understood. Here, we investigate in detail the electron phase space dynamics in a spontaneously generated falling tone chorus with a parabolic type magnetic field, where field strength decreases away from the equator. We demonstrate the formation and evolution of electron phase space clump from downstream to upstream regions, and show that the variation of frequency chirping rate is caused by the movement of the source region. The results are consistent with the recently proposed Trap‐Release‐Amplify model, and should be useful to understand the mechanism of chorus frequency chirping.