Antenna Placement Optimization for Distributed MIMO Radar Based on a Reinforcement Learning Algorithm.

This paper studies an optimization problem of antenna placement for multiple heading angles of the target in a distributed multiple-input multiple-output (MIMO) radar system. An improved method to calculate the system's coverage area in light of the changing target heading is presented. The antenna placement optimization problem is mathematically modelled as a sequential decision problem for compatibility with reinforcement learning solutions. A reinforcement learning agent is established, which uses the long short-term memory (LSTM)-based proximal policy optimization (PPO) method as the core algorithm to solve the antenna placement problem. Finally, the experimental findings demonstrate that the method can enhance the coverage area of antenna placement and thus has reference value for providing new ideas for the antenna placement optimization of distributed MIMO radar.

Temporal characteristics of agarwood formation in Aquilaria sinensis after applying whole-tree agarwood-inducing technique.

Objective: Agarwood-a resinous wood produced by Aquilaria plants in response to injury or artificial induction-is a valuable medicinal and fragrance resource. Whole-Tree Agarwood-Inducing Technique (Agar-WIT) has been widely used to produce agarwood. However, the time-dependent characteristics of agarwood formation induced by Agar-WIT are yet to be clarified. To promote technologically efficient utilization and upgradation of Agar-WIT, the dynamic process and mechanism of agarwood formation were analyzed for one year. Methods: Agarwood formation percentage, barrier layer microscopic properties, extract levels, compound level, and characteristic chromatograms of agarwood were examined by referring to the Chinese Pharmacopeia (2020 version). Results: Agar-WIT could maintain a high percentage of agarwood formation over one year compared with that of healthy plants. Alcohol-soluble extract and agarotetrol levels showed fluctuating cyclic changes with peaks occurring first during the fifth and sixth months, and subsequently in the 11th month. Aquilaria trees subjected to Agar-WIT treatment for 1-12 months showed significant characteristics of a dynamic agarwood formation process. The barrier layer began to appear in the fourth month after treatment. Alcohol-soluble extractive levels in agarwood formed in the second month, and thereafter, exceeded 10.0%, and agarotetrol in agarwood produced after four months or later, exceeded 0.10%. Conclusion: According to the Chinese Pharmacopoeia, alcohol-soluble extractive levels in agarwood should not be less than 10.0% and agarotetrol level should exceed 0.10%. After four months of Agar-WIT treatment, the formed agarwood theoretically met these standards and was suitable for developed and utilization. However, the optimal harvest time was found to be the 11th month, followed by the sixth month after Agar-WIT treatment. Therefore, Agar-WIT resulted in swift agarwood formation and stable accumulation of alcohol-soluble extracts and agarotetrol. Thus, this method is efficient for large-scale cultivation of Aquilaria sinensis to produce agarwood and provide raw materials for the agarwood medicinal industry.

PIMREG is a prognostic biomarker involved in immune microenvironment of clear cell renal cell carcinoma and associated with the transition from G1 phase to S phase.

Background: Clear cell renal cell carcinoma (ccRCC) is one of the most common tumors in the world and affects human health seriously. PIMREG is a mitotic regulator which is essential to the metaphase-to-anaphase transition in cell cycle. Although PIMREG plays a crucial role in the malignant progression of tumors, there are few reports on its role in ccRCC. Methods: The transcriptional expression profile and clinical data of PIMREG were downloaded from TCGA database and verified by qRT-PCR. Kaplan-Meier plotter was used to analyze the effect of PIMREG on overall survival (OS), disease specific survival (DSS) and progression-free interval (PFI) of patients with ccRCC. Univariable and multivariable Cox regression analysis were used to determine the independent prognostic factors of ccRCC. The effects of PIMREG on cell migration and invasion were detected by wound healing assay and transwell invasion assay, and CCK-8 assay, colony formation assay and cell cycle assay were used to detect the effect of PIMREG on cell proliferation. In addition, the changes in cell cycle related proteins were detected by western blot. Results: PIMREG was highly expressed in human ccRCC and was positively correlated with pathologic stage, TNM stage and histologic grade. In addition, patients with high expression of PIMREG had a poor prognosis. Univariable and multivariable Cox regression analysis identified that PIMREG was an independent prognostic factor of ccRCC. Additionally, PIMREG was also closely related to immune cell infiltration. Experiments in vitro identified that the knockdown of PIMREG could significantly inhibit the proliferation, migration and invasion abilities of ccRCC. The expression of cyclin D1, CDK4 and CDK6 was also significantly reduced after PIMREG knockdown. Conclusions: PIMREG plays a vital role in the development of ccRCC and may become a potential therapeutic target in the future.

[Characterization of AOX family members from Aquilaria sinensis and their responses to wounding].

Aquilaria sinensis is a typical inducible medicinal plant, that can produce agarwood only after it is wounded by external stimuli. Alternative oxidase(AOX) is one of the terminal oxidases of the plant mitochondrial electron transport, which plays an important role in plants' response to environmental stress. In order to reveal the physiological function of AOX gene in the process of agarwood formation from A.sinensis induced by wounding, AOX gene was cloned based on the transcriptome database and then identified by the bioinformatics analysis, and their expression pattern in different tissues and under wounding stress were detected by qRT-PCR. The results as follows. Three AOX genes were cloned from A.sinensis for the first time. They were named AsAOX1a, AsAOX1d and AsAOX2, respectively. The tissue expression shown that AsAOX1a is mainly expressed in the stem and the seed, and the AsAOX1d and AsAOX2 genes are mainly expressed in the pulp and the stem. AsAOX1a and AsAOX1d genes are highly responsive to wounding stress, and their response time was different. In addition, the expression of AsAOX1a and AsAOX2 induced by wounding are reduced by H_2O_2 treatment, but promoted by AsA treatment. The cloning, bioinformatics analysis and expression characteristics of AOX genes from A.sinensis provided basic information for further study the function of AOX genes in the development of A.sinensis, especially in the process of agarwood formation of A. sinensis induced by wounding.

[Effect of arsenic trioxide on differentiation induction of chronic myeloid leukemia k562 cells and its potential mechanism].

OBJECTIVE: This study was to explore the effect of arsenic trioxide (ATO; As(2)O(3)) on differentiation of chronic myeloid leukemia K562 cells and its potential mechanism. METHODS: ATO with different concentration (0.1, 0.5, 1.0, 2.0, 5.0 µmol/L) were used to treat K562 cells, and MTT assay was used to detect the growth level of K562 cells; Benzidine staining was applied to measure the change of hemoglobin content; flow cytometry (FCM) was conducted to detect the expression of CD41 and GPA on K562 cells; RT-PCR and Western blot were used to measure the mRNA expression of BTG1 and TAL1 and the protein expression of BTG1 and TAL1, respectively. RESULTS: ATO significantly inhibited the growth of K562 with dose- and time- dependent manners by benzidine staining, the positive rate of K562 cells induced by ATO reached to 17.63% ± 1.18%, which was significantly higher than that of control (2.87% ± 0.63%) (P < 0.01), and GPA, as the specific marker of erythroid cell differentiation, achieved 68.46% ± 3.67%, while it in control was 3.39% ± 0.84% (P < 0.01), besides, the CD41 expression of megakaryocyte increased but not so obvious as GPA. Meanwhile, the differentiation-related transcriptional factors TAL1 and BTG1 mRNA and the corresponding proteins were expressed more highly. CONCLUSION: ATO can induce the differentiation of K562 cells into erythroid cells and megakaryocyte, which is associated with up-regulation of the related transcription factors TAL1 and BTG1.