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6. Maximum Likelihood Data Fusion With Optimal Similarity Constraints for Full-Polarimetric RoPeR Imaging of Martian Regolith

Author

Zhou, Haoqiu, Feng, Xuan, Dong, Zejun, and Liu, Cai

Abstract

The Zhurong rover of the Chinese Tianwen-1 mission is equipped with a Mars rover penetrating radar (RoPeR). The high-frequency CH-2 antenna adopts a full-polarimetric (FP) acquisition mode to map the fine structure of the Martian regolith. However, the data from different polarimetric channels characterize different features of the subsurface. The accurate interpretation of regolith structure relies on a clear and comprehensive imaging result. This article proposes a new data fusion algorithm to achieve this goal, which is called the maximum likelihood method with optimal similarity constraints (ML-OSC). A unique loss function is constructed to guarantee the similarity between the fusion result and source radargrams and simultaneously consider the amplitude difference in different channel data. FP ground penetrating radar (FP-GPR) experiments on three typical targets are performed in the laboratory. The comparisons with three normal methods validate the effectiveness and superiority of the proposed method. Finally, the proposed method is applied to the field FP-RoPeR data fusion imaging. Several subsurface structures are analyzed in detail to verify its effectiveness in Martian regolith imaging. The proposed method provides new and complete imaging results of Martian regolith, which will lead to a more accurate interpretation of it in the future.

Published
2024
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7. Super-Resolution Detection of Millimeter-Scale Fractures With Fluid Flow Using Time-Lapse Full-Polarimetric GPR and Anisotropy Analysis

Author

Dong, Zejun, Feng, Xuan, Zhou, Haoqiu, Zhang, Minghe, Liu, Qian, An, Yafei, Zhang, Yinghao, Yang, Jiarun, Liang, Wenjing, Yu, Yue, and Liu, Cai

Abstract

Fractures with fluid flow can lead to the damage of rock carving relics. During the detection of fractures, millimeter-scale fractures are usually difficult to determine due to their small apertures. Considering the rapid variation of water content in the fracture seepage zone can lead to anisotropy, this article proposes a new methodology to detect these millimeter-scale fractures with fluid flow using a time-lapse full-polarimetric ground penetrating radar (FP-GPR) scheme and an anisotropy analysis method. The time-lapse FP-GPR detection can monitor the water flow in the fracture and the infiltration in the rock, and the Freeman decomposition, H-Alpha decomposition, and a polarimetric phase (PP) feature are adopted to quantify and analyze the anisotropic effects over time. In the numerical test, we adopt hydrological modeling to build realistic dielectric models for time-lapse FP-GPR simulations. The results indicate that the variations of water contents and several polarimetric features, i.e., the surface-like scattering power, the double-bounce scattering power, and the averaged scattering angle, are consistent and are essentially related to the anisotropy of the seepage zone. Finally, we introduce the field tests performed at the experimental station of the Dazu Rock Carvings in Chongqing, China, which contain two cases I and II. Case I is an experiment on a surface fracture of a cliff, whereas case II is a detection test of a buried fracture. The results verify the effectiveness of the proposed methodology.

Published
2024
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11. Quantification of human embryonic ζ-globin chains in Southeast Asian deletion (--SEA) carriers

Author

Ye, Yuhua, primary, Sun, Guoying, additional, Ren, Zhe, additional, Liang, Yidan, additional, Luo, Hualei, additional, Lin, Peng, additional, Wang, Xingmin, additional, Dong, Zejun, additional, Huang, Li, additional, Qin, Lang, additional, Yu, Wenfang, additional, Wang, Ge, additional, Zhou, Yuqiu, additional, Tang, Jia, additional, Lou, Jiwu, additional, Liu, Yanhui, additional, Zeng, Xianqi, additional, Chen, Yajun, additional, Li, Yihong, additional, Zhang, Qianqian, additional, Huang, Jin, additional, Zhu, Ping, additional, Lin, Liang, additional, Zhang, Xinhua, additional, and Xu, Xiangmin, additional

Published
2022
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21. Quantification of human embryonic ζ-globin chains in Southeast Asian deletion (--SEA) carriers

Author

Ye, Yuhua, Sun, Guoying, Ren, Zhe, Liang, Yidan, Luo, Hualei, Lin, Peng, Wang, Xingmin, Dong, Zejun, Huang, Li, Qin, Lang, Yu, Wenfang, Wang, Ge, Zhou, Yuqiu, Tang, Jia, Lou, Jiwu, Liu, Yanhui, Zeng, Xianqi, Chen, Yajun, Li, Yihong, Zhang, Qianqian, Huang, Jin, Zhu, Ping, Lin, Liang, Zhang, Xinhua, and Xu, Xiangmin

Abstract

AimsReactivation of embryonic ζ-globin is a promising strategy for genetic treatment of α-thalassaemia. However, quantification of ζ-globin as a quantitative trait in α-thalassaemia carriers and patients remains incompletely understood. In this study, we aimed to set up a reliable approach for the quantification of ζ-globin in α-thalassaemia carriers, followed by a population study to investigate its expression patterns.Methodsζ-globin was purified as monomers from cord blood haemolysate of a Hb Bart’s fetus, followed by absolute protein quantification, which was then tested by in-house ELISA system and introduced as protein standard. It was then used for large-scale quantification in peripheral blood samples from 6179 individuals. Finally, liquid chromatography-tandem mass spectrometry (LC-MS/MS) introduced as an independent validating approach by measuring ζ-globin expression in a second cohort of 141-SEA/αα carriers.ResultsThe ELISA system was proved sensitive in distinguishing individuals with varied extent of ζ-globin. Large scale quantitative study of this --SEA/αα carrier cohort indicated the high diversity of ζ-globin expression ranging from 0.00155 g/L to 1.48778 g/L. Significant positive correlation between ELISA and LC-MS/MS (R=0.400, p<0.001) was observed and it is more sensitive in distinguishing the samples with extreme expression of ζ-globin (R=0.650, p<0.001).ConclusionOur study has reported reliable approaches for the quantification of ζ-globin and presented the expression patterns of ζ-globin among the --SEA/αα carrier population, which might lay a foundation on subsequent genotype–phenotype studies on mechanisms of delayed haemoglobin switch in α-thalassaemia.

Published
2023
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35. Genome-Wide DNA Methylation Analysis During Palatal Fusion Reveals the Potential Mechanism of Enhancer Methylation Regulating Epithelial Mesenchyme Transformation

Author

Shu, Xuan, primary, Shu, Shenyou, additional, Cheng, Hongqiu, additional, Tang, Shijie, additional, Yang, Lujun, additional, Li, Haihong, additional, Zhang, Mingjun, additional, Zhu, Zhensen, additional, Liu, Dan, additional, Li, Ke, additional, Dong, Zejun, additional, Cheng, Liuhanghang, additional, and Ding, Jialong, additional

Published
2018
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42. Jamming effect of laser on infrared thermal imager’s automatic gain control circuit

Author

Dong Zejun, Zhang Lei, Zhang Hengwei, Ji Xiang, and Zhao Wei

Subjects
Physics, Infrared, business.industry, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Jamming, Laser, Grayscale, Atomic and Molecular Physics, and Optics, law.invention, Pulse period, Optics, Interference (communication), law, Thermal, Automatic gain control, Electrical and Electronic Engineering, business
Abstract

Based on the analysis of the working principle of automatic gain control (AGC) circuit, the mechanism of laser jamming on AGC circuit is discussed, and the experiment of laser jamming on the AGC circuit of an infrared thermal imaging device is carried out. An analysis method which uses the change of regional gray scale to test the gain of AGC circuit is then proposed. Finally, a quantitative analysis is conducted on the experiment data, and the result indicates that, the persistent effective interference of laser on AGC circuit of infrared thermal imaging device can be realized, on condition that the pulse period of interference laser is less than the adjustment time of automatic gain.

Published
2011
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43. Effects of Plumbagin on Platelet Aggregation and Platelet-Neutrophil Interactions

Author

Zhiqiang Shen, Ling Li, Jikai Liu, Peng Cheng, Zhihe Chen, and Dong Zejun

Subjects
Blood Platelets, Male, Platelet Aggregation, Neutrophils, Pharmaceutical Science, In Vitro Techniques, Pharmacology, Analytical Chemistry, chemistry.chemical_compound, Drug Discovery, Animals, Platelet, Platelet activation, Platelet Activating Factor, Arachidonic Acid, Platelet-activating factor, Organic Chemistry, Biological activity, Plumbagin, Adenosine Diphosphate, Adenosine diphosphate, Complementary and alternative medicine, chemistry, Biochemistry, Molecular Medicine, Arachidonic acid, Rabbits, Ex vivo, Naphthoquinones
Abstract

The effects of plumbagin were investigated on platelet aggregation in vitro and ex vivo, on the binding of thrombin-stimulated platelets to neutrophils, and platelet aggregation induced by intact neutrophils and N-formyl-methionyl-leucyl-phenylalanine (fMLP) or platelet activating factor (PAF) activated neutrophils, by use of the methods of Hamburger, McEver and Born, respectively. The results showed that plumbagin in vitro significantly inhibited adenosine diphosphate (ADP)-, arachidonic acid (AA)-, or platelet activating factor (PAF)-induced platelet aggregation, in a concentration-dependent manner. The medium inhibitory concentrations (IC 50 ) were 39.4, 82.7 and 38.1 microM, respectively. Intragastric plumbagin at 10 mg/kg markedly suppressed platelet aggregation induced by ADP, AA, or PAF. Plumbagin decreased the binding between thrombin-stimulated platelets and neutrophils with an IC 50 of 62.9 microM. Plumbagin significantly inhibited washed platelet aggregation stimulated by fMLP- or PAF-activated neutrophils. The IC 50 values were 54.3 and 47.6 microM, respectively. On the other hand, plumbagin and aspirin increased the inhibition of intact neutrophils on AA-induced platelet aggregation. It is suggested that plumbagin inhibited platelet aggregation in vitro and ex vivo, suppressed the binding of activated platelets to neutrophils, inhibited platelet aggregation induced by activated neutrophils, and increased inhibition of intact neutrophils on platelet reactivity. Abbreviations. DMSO:dimethyl sulphoxide fMLP: N-formyl-methionyl-leucyl-phenylalanine ADP:adenosine diphosphate AA:arachidonic acid PAF:platelet activating factor

Published
2003
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44. Modulation of PAI-1 and tPA activity and thrombolytic effects of corilagin

Author

Ji-Kai Liu, Hua Peng, Zhiqiang Shen, and Dong Zejun

Subjects
Male, Pharmaceutical Science, Pharmacology, Analytical Chemistry, Rats, Sprague-Dawley, chemistry.chemical_compound, Plasminogen Activators, Glucosides, In vivo, Drug Discovery, Plasminogen Activator Inhibitor 1, medicine, Animals, Urokinase, Dose-Response Relationship, Drug, business.industry, T-plasminogen activator, Plant Extracts, Organic Chemistry, Biological activity, Plant Components, Aerial, Urokinase-Type Plasminogen Activator, Hydrolyzable Tannins, Rats, Phyllanthus, Complementary and alternative medicine, Mechanism of action, Biochemistry, chemistry, Plasminogen activator inhibitor-1, Tissue Plasminogen Activator, Molecular Medicine, Rabbits, medicine.symptom, business, Corilagin, Plasminogen activator, medicine.drug, Phytotherapy
Abstract

In this study, Charlton's and Tomihisa's methods were modified to investigate the thrombolytic effect of corilagin from the Chinese herbal plant Phyllanthus urinaria L., as well as its effect on carotid artery patency status. The activity of type 1 plasminogen activator inhibitor (PAI-1) in rat plasma or platelet-released substances and tissue-type plasminogen activator (tPA) in rat plasma was assayed by use of a chromogenic substrate. The results showed that corilagin had a dose-dependent thrombolytic effect in rats. 5 mg/kg of corilagin produced a nearly similar reperfusion rate to that of 20000 U/kg of urokinase, whereas it produced a lower reocclusion rate than urokinase. Corilagin significantly inhibited PAI-1 activity in rat plasma or platelet-released substances while it elevated plasma tPA activity, in a concentration-dependent manner. Corilagin, however, had no influence on rabbit platelet aggregation. It is indicated that corilagin inhibited PAI-1 activity and increased tPA activity, and this property of corilagin is assumed to be responsible for the thrombolytic effect. Abbreviations. PO:persistent occlusion CR:cyclic reflow PP:persistent patency PAI-1:type 1 plasminogen activator inhibitor tPA:tissue-type plasminogen activator PBS:phosphate buffer solution IC (50):50 % of inhibitory concentration PRP:platelet-rich plasma ADP:adenosine diphosphate AA:arachidonic acid PAF:platelet-activating factor

Published
2004

49. Local Freeman Decomposition for Robust Imaging and Identification of Subsurface Anomalies Using Misaligned Full-Polarimetric GPR Data.

Author

Zhou, Haoqiu, Feng, Xuan, Dong, Zejun, Liu, Cai, Liang, Wenjing, and An, Yafei

Subjects
GROUND penetrating radar, SYNTHETIC aperture radar, PERMITTIVITY, ANTENNA arrays, HUMAN error
Abstract

A full-polarimetric ground penetrating radar (FP-GPR) uses an antenna array to detect subsurface anomalies. Compared to the traditional GPR, FP-GPR can obtain more abundant information about the subsurface. However, in field FP-GPR measurements, the arrival time of the received electromagnetic (EM) waves from different channels cannot be strictly aligned due to the limitations of human operation errors and the craftsmanship of the equipment. Small misalignments between the radargrams acquired from different channels of an FP-GPR can lead to erroneous identification results of the classic Freeman decomposition (FD) method. Here, we propose a local Freeman decomposition (LFD) method to enhance the robustness of the classic FD method when managing with misaligned FP-GPR data. The tests on three typical targets demonstrate that misalignments will severely interfere with the imaging and the identification results of the classic FD method for the plane and dihedral scatterers. In contrast, the proposed LFD method can produce smooth images and accurate identification results. Besides, the identification of the volume scatterer is not affected by misalignments. A test of ice-fracture detection further verifies the capability of the LFD method in field measurements. Due to the different relative magnitudes of the permittivity of the media on two sides of the interfaces, the ice surface and ice fracture show the features of surface-like and double-bounce scattering, respectively. However, the definition of double-bounce scattering is different from the definition in polarimetric synthetic aperture radar (SAR). Finally, a quantitative analysis shows that the sensitivities of the FD and LFD methods to misalignments are related to both the type of target and the polarized mode of the misaligned data. The tolerable range of the LFD method for misalignments is approximately ±0.2 times the wavelength of the EM wave, which is much wider than that of the FD method. In most cases, the LFD method can guarantee an accurate result of identification. [ABSTRACT FROM AUTHOR]

Published
2022
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