Hybrid Phased-MIMO SAR : Mode Design and Performance Analysis

Lele Zhang,Dianren Chen 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.9

In this paper, we introduce an innovative scanning synthetic aperture radar (SAR) termed as the Hybrid Phased-MIMO SAR (HPMSAR) and investigate the system performance. The HPMSAR overcomes the limitations imposed by the conventional scanning SAR (ScanSAR, spotlight SAR, or Terrain Observation by Progressive Scans (TOPS) SAR) and presents the strong flexibility in imaging mode. Every subarray in HPMSAR is simultaneously pointed in the different directions and electronically steers the azimuth beam. This not only increases the illumination time per subswath entailing a high azimuth resolution but also covers an ultra-wide swath giving short-term time for global coverage. However, multidirectional scanning imaging will produce overlapped echoes and ambiguities on receive, then this paper presents the advanced processing scheme based on two-dimension (2-D) digital beamforming (DBF) with multichannel unambiguous reconstruction technology. The key of this method lies that multichannel processing technology in azimuth ensures receiving echoes free of aliasing by using a low PRF, and 2-D DBF could effectively suppress ambiguities and separate the overlapped echoes from different subswaths. Performance analysis compared with traditional methods shows output performance of interference suppression.

Design & Research of Legal Affairs Information Service Platform Based on UIMA and Semantics

Wang Chen,Zhang Jia,Qin Lele 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.3

The law is the most powerful weapon to safeguard national stability and ensure flourishing of all causes as well as an instrument to protect the rights and interests of the masses, therefore, the just and accurate use of legal provisions is of crucial importance. With the increase of informatization level of the legal industry itself, more and more services in legal affairs are provided in information-based forms, and there is a large number of unstructured information in such business data. It’s a problem the legal industry needs to tackle in information management to rapidly acquire valuable content from the massive unstructured data and make use of such content. Based on analysis of problems arising in existing laws and regulations informatization system, this paper comes up with solution of a legal affairs information service platform based on cloud computing, UIMA, semantics, big data and Chinese word segmentation. This paper also proposes the four-layer technical framework solution on the basis of the design of integration and management method of unstructured data of heterology and isomerism, analyzing and processing method of unstructured data, semantics based unstructured information retrieval method and construction and maintenance method of ontology library. It also provides detailed introduction to the realization of the combination of big data and cloud computing and its application in this information platform by virtue of designing UFS - a distributed file system, MapReduce - a batch processing technology and BigTable - a distributed database. Data acquisition and expanded data analysis can be conducted by making use of the expandable UIMA framework and the sequential indexing of data content and analysis results can be materialized by means of applying Lucene indexing technology. With regard to information retrieval, the concept of ontology is introduced on the basis of traditional search model and a new search model based on domain ontology is proposed. IKAnalyzer 3.x is proposed to facilitate Chinese word segmentation. By taking advantage of such information service platform, legal affairs enterprises can effectively integrate structured and unstructured information resources and implement the storage, analysis, retrieval and decision-making applications of business data content.

LETM1 Promotes Gastric Cancer Cell Proliferation, Migration, and Invasion via the PI3K/Akt Signaling Pathway

Zhang, Yunfeng,Chen, Lele,Cao, Yifan,Chen, Si,Xu, Chao,Xing, Jun,Zhang, Kaiguang The Korean Gastric Cancer Association 2020 Journal of gastric cancer Vol.20 No.2

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

LETM1 Promotes Gastric Cancer Cell Proliferation, Migration, and Invasion via the PI3K/Akt Signaling Pathway

Yunfeng Zhang,Lele Chen,Yifan Cao,Si Chen,Chao Xu,Jun Xing,Kaiguang Zhang 대한위암학회 2020 Journal of gastric cancer Vol.20 No.2

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

Synthesis and antioxidant properties of a novel arylamine antioxidant

Chao Mianran,Fan Rong,Zhang Lulu,Wang Xiaoyu,Shu Qianhui,Gao Jifeng,Chen Lele,Gong Peiwei,Shen Duyi 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.11

A novel oil-soluble arylamine antioxidant N1 ,N2 -diphenylethane-1,2-diamine (ND) was successfully synthesized, and the potential antioxidant behavior of which had never been reported before. The structure of ND was characterized via nuclear magnetic resonance (1 H NMR, 13C NMR) and electron ionization mass spectrometry. The antioxidant performance of ND and its synergistic effect with 2,6-di-tert-butyl-4-methylphenol (BHT) in di-2-ethylhexyl sebacate were evaluated by pressurized differential scanning calorimetry, thermogravimetry analysis, and hot oil oxidation test. All the results indicated that the synthesized antioxidant ND exhibited outstanding antioxidant performance and showed prominent synergistic effect with BHT in ester base oil. Furthermore, the probable synergistic antioxidative effect between ND and BHT was discussed, which was mainly induced by the formation of a fresh BHT radical and the regeneration of ND antioxidant.