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【Objective】With the development of the sixth generation mobile communication technology, the inter-carrier interference in the traditional Orthogonal Frequency Division Multiplexing (OFDM) system makes the channel estimation performance insufficient to provide highly reliable communication, and Orthogonal Time-Frequency Space (OTFS) system can effectively solve the problem of communication system reliability degradation caused by fast time variability and Doppler effect, which has received wide attention in recent years.【Methods】In order to effectively meet the channel estimation performance requirements of OTFS systems, this paper uses an Optimized Generalized Complex Exponential (OGCE) Basis Expansion Model (BEM) to calculate the channel impulse response as a time-invariant basis function with basis function coefficients, which can effectively fit fast time-varying channels in high-speed mobile communication scenarios. The OGCE-BEM improves the spectral leakage by more intensive sampling and reduces the error of the high-frequency basis model by adding correction coefficients to reduce the error of the HF-based model.【Results】The simulation results show that the proposed algorithm is suitable for high-speed mobile communication scenarios with more reasonable design of the basis function. The estimation method has lower mean square error than the fixed forgetting factor, and the channel estimation results are more accurate. Compared with Least Square (LS), BEM-LS and BEM-Linear Minimum Mean Square Error (LMMSE) channel estimation methods, the performance of mean square error is significantly improved.【Conclusion】It can be seen that the channel estimation algorithm based on OGCE-BEM can effectively reduce the number of unknown parameters to be estimated and improve the accuracy of channel estimation.

Sprite halos are diffuse glow discharges in the D-region ionosphere triggered by the quasi-electrostatic (QES) fields of lightning discharges. A three-dimensional (3D) QES model is adopted to investigate the effect of ionospheric electron density on sprite halos. The electron density is described by an exponential formula, parameterized by reference height (h') and sharpness (β), and the local inhomogeneity has a Gaussian density distribution. Simulation results indicate that the reference height and steepness of the nighttime electron density affect the penetration altitudes and amplitudes of normalized electric fields, as well as the altitudes and intensities of the corresponding sprite halos optical emissions. A comparison of the daytime and nighttime conditions demonstrates that the daytime electron density profile is not favorable for generating sprite halos emissions. Furthermore, the pre-existing electron density inhomogeneities lead to enhanced local electric fields and optical emissions, potentially offering a plausible explanation for the horizontal displacement between sprites and their parent lightning, as well as their clustering. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to assess the expression levels of NAP1L5 in individuals diagnosed with acute myeloid leukemia (AML) and to investigate its clinical and prognostic significance in those with primary AML., Methods: Between June 2021 and June 2023, the Department of Hematology at the First Affiliated Hospital of Bengbu Medical University collected 100 bone marrow specimens from primary AML patients and 30 from individuals with idiopathic thrombocytopenic purpura (ITP) for this medical research study. The researchers gathered comprehensive clinical data from patients diagnosed with acute myeloid leukemia (AML). Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to measure the mRNA levels of NAP1L5 in both the ex-perimental and the control group. The investigation involved analyzing the association between NAP1L5 expres-sion related to AML, clinical features, and overall prognosis. The study employed the Kaplan-Meier method to evaluate the impact of NAP1L5 expression on the overall survival time (OS) in AML patients, while the Cox hazard regression model was used to identify significant prognostic factors., Results: NAP1L5 was found to be significantly more expressed in individuals with AML compared to those with ITP. Patients diagnosed with AML and exhibiting elevated NAP1L5 expression levels correlated with older age, ineffective response to chemotherapy, and a more unfavorable prognosis compared to those with lower NAP1L5 expression. Additionally, the group with high expression demonstrated a noticeably decreased overall survival (OS), compared to the group with low expression. Furthermore, a significant association was observed between the elevated NAP1L5 expression levels and an unfavorable clinical outcome in patients diagnosed with AML., Conclusions: The initial exploration of the elevated expression of NAP1L5 in AML and its clinical significance offers potential targets for AML treatment and prognostic evaluation.