138 results on '"Jie Chen"'
Search Results
2. Efficient Proximal Gradient Algorithms for Joint Graphical Lasso
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Ryosuke Shimmura, Joe Suzuki, and Jie Chen
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FOS: Computer and information sciences ,Computer science ,Science ,QC1-999 ,General Physics and Astronomy ,Machine Learning (stat.ML) ,Astrophysics ,Article ,Lasso (statistics) ,Simple (abstract algebra) ,Statistics - Machine Learning ,FOS: Mathematics ,Graphical model ,Mathematics - Optimization and Control ,Sparse matrix ,Efficient algorithm ,Backtracking ,Physics ,joint graphical lasso ,QB460-466 ,Gaussian graphical model ,proximal gradient descent method ,Optimization and Control (math.OC) ,Iterated function ,Joint (audio engineering) ,Algorithm - Abstract
We consider learning an undirected graphical model from sparse data. While several efficient algorithms have been proposed for graphical lasso (GL), the alternating direction method of multipliers (ADMM) is the main approach taken concerning for joint graphical lasso (JGL). We propose proximal gradient procedures with and without a backtracking option for the JGL. These procedures are first-order and relatively simple, and the subproblems are solved efficiently in closed form. We further show the boundedness for the solution of the JGL problem and the iterations in the algorithms. The numerical results indicate that the proposed algorithms can achieve high accuracy and precision, and their efficiency is competitive with state-of-the-art algorithms., 23 pages, 5 figures
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- 2021
3. Study on the Roof Solar Heating Storage System of Traditional Residences in Southern Shaanxi, China
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Bart Dewancker, Jie Chen, Jing Mao, Shuo Chen, and Simin Yang
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China ,southern Shaanxi ,Hot Temperature ,business.industry ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental engineering ,Temperature ,Article ,thermal storage roof pool ,Heating ,solar heating system ,traditional residence ,Computer data storage ,Housing ,Environmental science ,Medicine ,business ,Roof - Abstract
Solar energy is a renewable, green, clean, and universal resource that has great potential in rural areas. Combining solar heating technology with building design to increase indoor thermal comfort in winter is an effective energy-saving and environmentally friendly approach. The factors affecting solar building heating mainly include two aspects; one is the lighting area of the building, and the other is the storage of building materials. By increasing the lighting area and using materials with good heat preservation and storage performance, the indoor temperature in winter can be effectively increased, and the heating time can be prolonged, thus decreasing the energy requirements of the building. In this paper, traditional houses in cold winter areas are selected as the research object, and a roof solar heating storage system is proposed. The method is to transform the opaque roof of the traditional houses into a transparent glass roof, and the thermal insulation and heat storage material HDPE is installed in the attic floorboards. The working principle of this system is to increase the amount of indoor solar radiation to raise the indoor temperature and make use of the thermal insulation performance of heat storage materials to prolong the indoor heating time. Through ANSYS software simulation, the heat transfer process, heat transfer mode, and temperature change of the system are analyzed, and the energy saving of the system is analyzed. The system can effectively raise the indoor temperature and has good energy-saving performance. The indoor temperature is raised by 5.8 °C, and the annual heat load of the building is reduced by 1361.92 kW·h, with a reduction rate of 25.02%.
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- 2021
4. A Rational Designed Novel Bispecific Antibody for the Treatment of GBM
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Huifang Zong, Lei Han, Jie Chen, Yanlin Bian, Baohong Zhang, Rui Sun, Zhidi Pan, Hua Jiang, Jianwei Zhu, and Yuexian Zhou
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EGFRvIII ,biology ,business.industry ,QH301-705.5 ,medicine.medical_treatment ,Immunogenicity ,Medicine (miscellaneous) ,Nod ,GBM ,General Biochemistry, Genetics and Molecular Biology ,In vitro ,Article ,bispecific antibody ,Cancer immunotherapy ,In vivo ,split intein ,Cancer research ,biology.protein ,Cytotoxic T cell ,Medicine ,Cytokine secretion ,Epidermal growth factor receptor ,Biology (General) ,business - Abstract
Epidermal growth factor receptor variant III (EGFRvIII) is highly and specifically expressed in a subset of lethal glioblastoma (GBM), making the receptor a unique therapeutic target for GBM. Recently, bispecific antibodies (BsAbs) have shown exciting clinical benefits in cancer immunotherapy. Here, we report remarkable results for GBM treatment with a BsAb constructed by the “BAPTS” method. The BsAb was characterized through LC/MS, SEC-HPLC, and SPR. Furthermore, the BsAb was evaluated in vitro for bioactivities through FACS, antigen-dependent T-cell-mediated cytotoxicity, and a cytokine secretion assay, as well as in vivo for antitumor activity and pharmacokinetic (PK) parameters through immunodeficient NOD/SCID and BALB/c mouse models. The results indicated that the EGFRvIII-BsAb eliminated EGFRvIII-positive GBM cells by recruiting and stimulating effector T cells secreting cytotoxic cytokines that killed GBM cells in vitro. The results demonstrated the antitumor potential and long circulation time of EGFRvIII-BsAb in NOD/SCID mice bearing de2–7 subcutaneously heterotopic transplantation tumors and BALB/c mice. In conclusion, our experiments in both in vitro and in vivo have shown the remarkable antitumor activities of EGFRvIII-BsAb, highlighting its potential in clinical applications for the treatment of GBM. Additional merits, including a long circulation time and low immunogenicity, have also made the novel BsAb a promising therapeutic candidate.
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- 2021
5. Full-Length Transcriptome Sequencing Provides Insights into Flavonoid Biosynthesis in Fritillaria hupehensis
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Xianming Lin, Kunyuan Guo, Jie Chen, and Yan Niu
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0106 biological sciences ,0301 basic medicine ,third generation sequencing ,Computational biology ,Biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Biosynthesis ,Fritillaria hupehensis ,medicinal plant ,Medicinal plants ,lcsh:Science ,Ecology, Evolution, Behavior and Systematics ,Paleontology ,Bulb ,Transcriptome Sequencing ,Metabolic pathway ,030104 developmental biology ,Flavonoid biosynthesis ,chemistry ,Space and Planetary Science ,genomic analysis ,herbal medicine ,Microsatellite ,lcsh:Q ,010606 plant biology & botany - Abstract
One of the most commonly utilized medicinal plants in China is Fritillaria hupehensis (Hsiao et K.C. Hsia). However, due to a lack of genomic resources, little is known about the biosynthesis of relevant compounds, particularly the flavonoid biosynthesis pathway. A PacBio RS II sequencing generated a total of 342,044 reads from the bulb, leaf, root, and stem, of which 316,438 were full-length (FL) non-redundant reads with an average length of 1365 bp and a N50 of 1888 bp. There were also 38,607 long non-coding RNAs and 7914 simple sequence repeats detected. To improve our understanding of processes implicated in regulating secondary metabolite biosynthesis in F. hupehensis tissues, we evaluated potential metabolic pathways. Overall, this study provides a repertoire of FL transcripts in F. hupehensis for the first time, and it will be a valuable resource for marker-assisted breeding and research into bioactive compounds for medicinal and pharmacological applications.
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- 2021
6. Preparation of a Fucoidan-Grafted Hyaluronan Composite Hydrogel for the Induction of Osteoblast Differentiation in Osteoblast-Like Cells
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Wen-Chieh Sung, Jheng-Jie Chen, Fu-Yin Hsu, and Pai-An Hwang
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Biocompatibility ,0206 medical engineering ,02 engineering and technology ,lcsh:Technology ,Fucose ,Article ,hyaluronan ,chemistry.chemical_compound ,Tissue engineering ,fucoidan ,medicine ,General Materials Science ,lcsh:Microscopy ,lcsh:QC120-168.85 ,lcsh:QH201-278.5 ,lcsh:T ,Fucoidan ,technology, industry, and agriculture ,Osteoblast ,021001 nanoscience & nanotechnology ,020601 biomedical engineering ,medicine.anatomical_structure ,chemistry ,lcsh:TA1-2040 ,Self-healing hydrogels ,Biophysics ,osteoblast ,Surface modification ,Alkaline phosphatase ,lcsh:Descriptive and experimental mechanics ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,hydrogel ,lcsh:Engineering (General). Civil engineering (General) ,0210 nano-technology ,lcsh:TK1-9971 - Abstract
A suitable bone substitute is necessary in bone regenerative medicine. Hyaluronan (HA) has excellent biocompatibility and biodegradability and is widely used in tissue engineering. Additionally, research on fucoidan (Fu), a fucose- and sulfate-rich polysaccharide from brown seaweed, for the promotion of bone osteogenic differentiation has increased exponentially. In this study, HA and Fu were functionalized by grafting methacrylic groups onto the backbone of the chain. Methacrylate-hyaluronan (MHA) and methacrylate-fucoidan (MFu) were characterized by FTIR and 1H NMR spectroscopy to confirm functionalization. The degrees of methacrylation (DMs) of MHA and MFu were 9.2% and 98.6%, respectively. Furthermore, we evaluated the mechanical properties of the hydrogels formed from mixtures of photo-crosslinkable MHA (1%) with varying concentrations of MFu (0%, 0.5%, and 1%). There were no changes in the hardness values of the hydrogels, but the elastic modulus decreased upon the addition of MFu, and these mechanical properties were not significantly different with or without preosteoblastic MG63 cell culture for up to 28 days. Furthermore, the cell morphologies and viabilities were not significantly different after culture with the MHA, MHA-MFu0.5, or MHA-MFu1.0 hydrogels, but the specific activity and mineralization of alkaline phosphatase (ALP) were significantly higher in the MHA-MFu1.0 hydrogel group compared to the other hydrogels. Hence, MHA-MFu composite hydrogels are potential bone graft materials that can provide a flexible structure and favorable niche for inducing bone osteogenic differentiation.
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- 2021
7. Energy Storage and Electrocaloric Cooling Performance of Advanced Dielectrics
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Mudassar Maraj, Jie Chen, Yalong Zhang, Biaolin Peng, Huiyu Dan, and Wenhong Sun
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Materials science ,Polymers ,Pharmaceutical Science ,02 engineering and technology ,Dielectric ,Review ,Pulsed power ,010402 general chemistry ,Electric Capacitance ,01 natural sciences ,Energy storage ,Analytical Chemistry ,law.invention ,GaN ,lcsh:QD241-441 ,energy storage density ,Electric Power Supplies ,lcsh:Organic chemistry ,Electricity ,law ,Drug Discovery ,ferroelectric materials ,Physical and Theoretical Chemistry ,Polarization (electrochemistry) ,Organic Chemistry ,low-temperature polarization ,021001 nanoscience & nanotechnology ,Engineering physics ,Ferroelectricity ,0104 chemical sciences ,electrocaloric effect ,Cold Temperature ,Capacitor ,Chemistry (miscellaneous) ,visual_art ,Electronic component ,dielectric materials ,visual_art.visual_art_medium ,Electrocaloric effect ,Molecular Medicine ,0210 nano-technology ,Energy Metabolism - Abstract
Dielectric capacitors are widely used in pulse power systems, electric vehicles, aerospace, and defense technology as they are crucial for electronic components. Compact, lightweight, and diversified designs of electronic components are prerequisites for dielectric capacitors. Additionally, wide temperature stability and high energy storage density are equally important for dielectric materials. Ferroelectric materials, as special (spontaneously polarized) dielectric materials, show great potential in the field of pulse power capacitors having high dielectric breakdown strength, high polarization, low-temperature dependence and high energy storage density. The first part of this review briefly introduces dielectric materials and their energy storage performance. The second part elaborates performance characteristics of various ferroelectric materials in energy storage and refrigeration based on electrocaloric effect and briefly shed light on advantages and disadvantages of various common ferroelectric materials. Especially, we summarize the polarization effects of underlying substrates (such as GaN and Si) on the performance characteristics of ferroelectric materials. Finally, the review will be concluded with an outlook, discussing current challenges in the field of dielectric materials and prospective opportunities to assess their future progress.
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- 2021
8. Multi-Functional Properties of MWCNT/PVA Buckypapers Fabricated by Vacuum Filtration Combined with Hot Press: Thermal, Electrical and Electromagnetic Shielding
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Liyang Cao, Yu Pan, Yunhai Zhang, Ning Wang, Jing Wang, Yongsheng Liu, and Jie Chen
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Materials science ,General Chemical Engineering ,Carbon nanotube ,Polyvinyl alcohol ,Article ,law.invention ,lcsh:Chemistry ,chemistry.chemical_compound ,Thermal conductivity ,law ,Electrical resistivity and conductivity ,Thermal ,General Materials Science ,thermal conductivity ,Composite material ,Nanocomposite ,electrical conductivity ,chemistry ,lcsh:QD1-999 ,finite element ,visual_art ,Electronic component ,Electromagnetic shielding ,visual_art.visual_art_medium ,hot press ,MWCNT buckypaper ,vacuum filtration - Abstract
The applications of pure multi-walled carbon nanotubes (MWCNTs) buckypapers are still limited due to their unavoidable micro/nano-sized pores structures. In this work, polyvinyl alcohol (PVA) was added to a uniform MWCNTs suspension to form MWCNT/PVA buckypapers by vacuum infiltration combined with a hot press method. The results showed an improvement in the thermal, electrical, and electromagnetic interference (EMI) shielding properties due to the formation of dense MWCNTs networks. The thermal and electrical properties rose from 1.394 W/m·, k to 2.473 W/m·, k and 463.5 S/m to 714.3 S/m, respectively. The EMI performance reached 27.08 dB. On the other hand, ABAQUS finite element software was used to simulate the coupled temperature-displacement performance. The electronic component module with buckypapers revealed a homogeneous temperature and thermal stress distribution. In sum, the proposed method looks promising for the easy preparation of multi-functional nanocomposites at low-cost.
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- 2020
9. RSI-CB: A Large-Scale Remote Sensing Image Classification Benchmark Using Crowdsourced Data
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Min Deng, Chao Tao, Xin Dou, Ling Zhao, Wu Zhixiang, Haifeng Li, Jian Peng, and Jie Chen
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Computer science ,deep convolution neural network ,crowdsourced data ,Big data ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,0211 other engineering and technologies ,02 engineering and technology ,lcsh:Chemical technology ,Biochemistry ,Convolutional neural network ,Field (computer science) ,Article ,Analytical Chemistry ,benchmark ,0202 electrical engineering, electronic engineering, information engineering ,remote sensing image classification ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,021101 geological & geomatics engineering ,Remote sensing ,Pixel ,Contextual image classification ,business.industry ,Atomic and Molecular Physics, and Optics ,Remote sensing (archaeology) ,Benchmark (computing) ,020201 artificial intelligence & image processing ,business - Abstract
Image classification is a fundamental task in remote sensing image processing. In recent years, deep convolutional neural networks (DCNNs) have experienced significant breakthroughs in natural image recognition. The remote sensing field, however, is still lacking a large-scale benchmark similar to ImageNet. In this paper, we propose a remote sensing image classification benchmark (RSI-CB) based on massive, scalable, and diverse crowdsourced data. Using crowdsourced data, such as Open Street Map (OSM) data, ground objects in remote sensing images can be annotated effectively using points of interest, vector data from OSM, or other crowdsourced data. These annotated images can, then, be used in remote sensing image classification tasks. Based on this method, we construct a worldwide large-scale benchmark for remote sensing image classification. This benchmark has large-scale geographical distribution and large total image number. It contains six categories with 35 sub-classes of more than 24,000 images of size 256 ×, 256 pixels. This classification system of ground objects is defined according to the national standard of land-use classification in China and is inspired by the hierarchy mechanism of ImageNet. Finally, we conduct numerous experiments to compare RSI-CB with the SAT-4, SAT-6, and UC-Merced data sets. The experiments show that RSI-CB is more suitable as a benchmark for remote sensing image classification tasks than other benchmarks in the big data era and has many potential applications.
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- 2020
10. Genome-Wide Analysis Reveals Human-Mediated Introgression from Western Pigs to Indigenous Chinese Breeds
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Chengkun Liu, Meiying Fang, Jue Wang, Kejun Wang, Yubei Wang, Ying Bai, and Jie Chen
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0106 biological sciences ,0301 basic medicine ,lcsh:QH426-470 ,Swine ,Genome wide analysis ,genome-wide variation ,introgression ,Introgression ,artificial selection ,Biology ,Breeding ,Genetic Introgression ,010603 evolutionary biology ,01 natural sciences ,Genome ,Polymorphism, Single Nucleotide ,Indigenous ,Article ,Glucose absorption ,03 medical and health sciences ,Genetic variation ,Genetics ,Animals ,Humans ,Selection, Genetic ,Gene ,Genetics (clinical) ,pigs ,Genetic Variation ,lcsh:Genetics ,030104 developmental biology ,Evolutionary biology ,SNP array - Abstract
Genetic variations introduced via introgression from Western to Chinese pigs have contributed to the performance of Chinese breeds in traits such as growth rate and feed conversion efficiency. However, little is known about the underlying genomic changes that occurred during introgression and the types of traits affected by introgression. To address these questions, 525 animals were characterized using an SNP array to detect genomic regions that had been introgressed from European to indigenous Chinese breeds. The functions of genes located in introgressed regions were also investigated. Our data show that five out of six indigenous Chinese breeds show evidence of introgression from Western pigs, and eight introgressed genome regions are shared by five of the Chinese breeds. A region located on chr13: 12.8&ndash, 13.1 M was affected by both introgression and artificial selection, and this region contains the glucose absorption related gene, OXSM, and the sensory related gene, NGLY. The results provide a foundation for understanding introgression from Western to indigenous Chinese pigs.
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- 2020
11. A Novel Anti-PD-L1 Vaccine for Cancer Immunotherapy and Immunoprevention
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Zhoushi Chen, Kuan-Der Lee, Jie Chen, Hsieh-Tsung Shen, Lindsey Jones, Xue F. Huang, Tiffany Jehng, Yanqing Li, Si-Yi Chen, and Hui Liu
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0301 basic medicine ,PD-L1 ,Cancer Research ,T cell ,medicine.medical_treatment ,Article ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,Antigen ,Cancer immunotherapy ,medicine ,dendritic cells ,immune checkpoint ,biology ,business.industry ,Immunotherapy ,Immune checkpoint ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,biology.protein ,tumor vaccine ,Cancer vaccine ,immunotherapy ,Antibody ,business - Abstract
Dendritic cells (DCs) are potent antigen-presenting cells that play a critical role in activating cellular and humoral immune responses. DC-based tumor vaccines targeting tumor-associated antigens (TAAs) have been extensively tested and demonstrated to be safe and potent in inducing anti-TAA immune responses in cancer patients. Sipuleucel-T (Provenge), a cancer vaccine of autologous DCs loaded with TAA, was approved by the United States Food and Drug Administration (FDA) for the treatment of castration-resistant prostate cancer. Sipuleucel-T prolongs patient survival, but has little or no effect on clinical disease progression or biomarker kinetics. Due to the overall limited clinical efficacy of tumor vaccines, there is a need to enhance their potency. PD-L1 is a key immune checkpoint molecule and is frequently overexpressed on tumor cells to evade antitumor immune destruction. Repeated administrations of PD-L1 or PD-1 antibodies have induced sustained tumor regression in a fraction of cancer patients. In this study, we tested whether vaccinations with DCs, loaded with a PD-L1 immunogen (PDL1-Vax), are able to induce anti-PD-L1 immune responses. We found that DCs loaded with PDL1-Vax induced anti-PD-L1 antibody and T cell responses in immunized mice and that PD-L1-specific CTLs had cytolytic activities against PD-L1+ tumor cells. We demonstrated that vaccination with PDL1-Vax DCs potently inhibited the growth of PD-L1+ tumor cells. In summary, this study demonstrates for the first time the principle and feasibility of DC vaccination (PDL1-Vax) to actively induce anti-PD-L1 antibody and T cell responses capable of inhibiting PD-L1+ tumor growth. This novel anti-PD-L1 vaccination strategy could be used for cancer treatment and prevention.
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- 2019
12. Effects of Dietary Supplementation with dl-Methionine and dl-Methionyl-dl-Methionine in Breeding Pigeons on the Carcass Characteristics, Meat Quality and Antioxidant Activity of Squabs
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Xiu-Qi Wang, N.X. Pan, Chun-Qi Gao, Hui-Chao Yan, Meng-Jie Chen, and Shi-Guang Jiang
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0301 basic medicine ,Antioxidant ,Physiology ,dl-methionine ,medicine.medical_treatment ,Clinical Biochemistry ,squabs ,antioxidant activity ,Superoxide dismutase activity ,Biochemistry ,dl-methionyl-dl-methionine ,Article ,meat quality ,03 medical and health sciences ,Animal science ,medicine ,Dietary supplementation ,dl<%2Fspan>-methionine%22">dl-methionine ,Molecular Biology ,DL-methionine ,Completely randomized design ,biology ,0402 animal and dairy science ,Thigh muscle ,04 agricultural and veterinary sciences ,Cell Biology ,dl<%2Fspan>-methionyl-dl<%2Fspan>-methionine%22">dl-methionyl-dl-methionine ,040201 dairy & animal science ,carcass characteristics ,Bioavailability ,030104 developmental biology ,Catalase ,biology.protein - Abstract
This study aimed to investigate the effects of dietary supplementation with dl-methionine (dl-Met) and dl-methionyl-dl-methionine (dl-Met-Met) in breeding pigeons on the carcass characteristics, meat quality and antioxidant activity of squabs. A total of 324 pairs of breeding pigeons were selected and allotted to 9 treatments in a completely randomized design, and the birds were fed dietary treatments for 45 d, including a Met-deficient basal diet (BD, crude protein = 15%, Met = 0.25%) and BD + 0.15%, 0.30%, 0.45%, or 0.60% dl-Met or dl-Met-Met diets. Compared with the diet fed to the BD group, dietary dl-Met or dl-Met-Met supplementation effectively increased the carcass yield, semieviscerated yield, eviscerated yield, breast muscle yield, thigh muscle yield, a* value, catalase activity, total superoxide dismutase activity and glutathione peroxidase activity, but decreased the L* value, malonaldehyde concentration, drip loss and cooking loss of squabs (p <, 0.05). The relative bioavailability values of dl-Met-Met relative to those of dl-Met were 467% and 376% based on carcass yield and breast muscle yield, respectively (p <, 0.001). Moreover, dl-Met-Met was more effective than dl-Met in decreasing the drip loss and improving the antioxidant activity of the breast and thigh muscles of squabs (p <, 0.05). As a source of Met, dl-Met-Met, rather than dl-Met, was more beneficial to squabs.
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- 2019
13. Study on Capacity Estimation Methods of Second-Life Application Batteries.
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Linkang Ma, Caiping Zhang, Jinyu Wang, Kairang Wang, and Jie Chen
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ELECTRIC batteries ,DATA analysis ,MULTICOLLINEARITY ,COMPUTER algorithms ,REGRESSION analysis - Abstract
For the capacity estimation problem of cells in series-retired battery modules, this paper proposed three different methods from the perspective of data-driven, battery curve matching and recession characteristics for different applications. Firstly, based on the premise that the battery history data are available, the features of the IC curve are selected as input for the linear regression models. To avoid multicollinearity among features, we apply a filter-based feature selection method to eliminate redundant features. The results show that the average errors with Multiple Linear Regression are within 1.5%. Secondly, for the situation with a lack of historical operating data, the battery-curve-matching-based method is proposed based on the Dynamic TimeWarping algorithm. This method could achieve the curve matching between the reference cell and target cell, and then the curve contraction coefficients can be obtained. The result shows that the method's average error is 2.34%. Thirdly, whereas the tougher situation is that only part of the battery curve is available, we present a substitute method based on the battery degradation mechanism. This method can estimate most of the battery plant capacity through the partial battery curve. The result shows that the method's average error is within 2%. Lastly, we contrast the applicability and limitations of every method based on the retired battery test data after deep cycling aging. [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
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14. Formation Tracking Control for Multi-Agent Networks with Fixed Time Convergence via Terminal Sliding Mode Control Approach.
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Guang-Hui Xu, Meng Li, Jie Chen, Qiang Lai, and Xiao-Wen Zhao
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This paper investigates formation tracking control for multi-agent networks with fixed time convergence. The control task is that the follower agents are required to form a prescribed formation within a fixed time and the geometric center of the formation moves in sync with the leader. First, an error system is designed by using the information of adjacent agents and a new control protocol is designed based on the error system and terminal sliding mode control (TSMC). Then, via employing the Lyapunov stability theorem and the fixed time stability theorem, the control task is proved to be possible within a fixed time and the convergence time can be calculated by parameters. Finally,numerical results illustrate the feasibility of the proposed control protocol. [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
- View/download PDF
15. Sentinel-1 InSAR Measurements of Elevation Changes over Yedoma Uplands on Sobo-Sise Island, Lena Delta
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Hui Lin, Guido Grosse, Lin Liu, Jie Chen, and Frank Günther
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Delta ,010504 meteorology & atmospheric sciences ,Global warming ,0211 other engineering and technologies ,Yedoma ,Elevation ,Subsidence ,02 engineering and technology ,15. Life on land ,Permafrost ,01 natural sciences ,Sentinel-1 InSAR ,Yedoma uplands ,Sobo-Sise Island ,summer heave ,permafrost thaw subsidence ,active layer ,13. Climate action ,Air temperature ,Interferometric synthetic aperture radar ,General Earth and Planetary Sciences ,Physical geography ,ddc:620 ,Mathematisch-Naturwissenschaftliche Fakultät ,Geology ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Abstract
Yedoma—extremely ice-rich permafrost with massive ice wedges formed during the Late Pleistocene—is vulnerable to thawing and degradation under climate warming. Thawing of ice-rich Yedoma results in lowering of surface elevations. Quantitative knowledge about surface elevation changes helps us to understand the freeze-thaw processes of the active layer and the potential degradation of Yedoma deposits. In this study, we use C-band Sentinel-1 InSAR measurements to map the elevation changes over ice-rich Yedoma uplands on Sobo-Sise Island, Lena Delta with frequent revisit observations (as short as six or 12 days). We observe significant seasonal thaw subsidence during summer months and heterogeneous inter-annual elevation changes from 2016–17. We also observe interesting patterns of stronger seasonal thaw subsidence on elevated flat Yedoma uplands by comparing to the surrounding Yedoma slopes. Inter-annual analyses from 2016–17 suggest that our observed positive surface elevation changes are likely caused by the delayed progression of the thaw season in 2017, associated with mean annual air temperature fluctuations.
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- 2018
16. Preparation of Molecularly Imprinted Microspheres as Biomimetic Recognition Material for In Situ Adsorption and Selective Chemiluminescence Determination of Bisphenol A
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Yan Xiong, Ming Duan, Jing Xu, Qing Wang, Jie Chen, and Shenwen Fang
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Bisphenol A ,endocrine system ,Polymers and Plastics ,Ethylene glycol dimethacrylate ,bisphenol A ,02 engineering and technology ,01 natural sciences ,Article ,Luminol ,law.invention ,lcsh:QD241-441 ,chemistry.chemical_compound ,Adsorption ,lcsh:Organic chemistry ,law ,molecularly imprinted microsphere (MIMS) ,Chemiluminescence ,Detection limit ,in situ adsorption ,urogenital system ,010401 analytical chemistry ,selectivity ,Periodate ,General Chemistry ,021001 nanoscience & nanotechnology ,Pickering emulsion ,0104 chemical sciences ,chemistry ,0210 nano-technology ,hormones, hormone substitutes, and hormone antagonists ,chemiluminescence determination ,Nuclear chemistry - Abstract
Bisphenol A (BPA) is an endocrine disrupter in environments which can induce abnormal differentiation of reproductive organs by interfering with the action of endogenous gonadal steroid hormones. In this work, the bisphenol A (BPA) molecularly-imprinted microspheres (MIMS) were prepared and used as biomimetic recognition material for in situ adsorption and selective chemiluminescence (CL) determination of BPA. Through non-covalent interaction, the BPA-MIMS was successfully prepared by Pickering emulsion polymerization using a BPA template, 4-vinylpyridine (4-VP) monomer, ethylene glycol dimethacrylate (EGDMA) cross-linker, and a SiO2 dispersion agent. The characterization of scanning electron microscopy (SEM) and energy-disperse spectroscopy (EDS) showed that the obtained MIMS possessed a regular spherical shape and narrow diameter distribution (25–30 μm). The binding experiment indicated BPA could be adsorbed in situ on the MIMS-packing cell with an apparent maximum amount Qmax of 677.3 μg g−1. Then BPA could be selectively detected by its sensitive inhibition effect on the CL reaction between luminol and periodate (KIO4), and the inhibition mechanism was discussed to reveal the CL reaction process. The CL intensity was linear to BPA concentrations in two ranges, respectively from 0.5 to 1.5 μg mL−1 with a detection limit of 8.0 ng mL−1 (3σ), and from 1.5 to 15 μg mL−1 with a limit of detection (LOD) of 80 ng mL−1 (3σ). The BPA-MIPMS showed excellent selectivity for BPA adsorption and the proposed CL method has been successfully applied to BPA determination in environmental water samples.
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- 2018
17. Using impedance measurements to characterize surface modified with gold nanoparticles
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Marcus Tamura, Zhimin Yan, Gaser N. Abdelrasoul, Scott MacKay, Jie Chen, and Donghai Lin
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Materials science ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,lcsh:Chemical technology ,01 natural sciences ,Biochemistry ,Article ,Analytical Chemistry ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,Electrical impedance ,point-of-care biosensor ,chemistry.chemical_classification ,Biomolecule ,impedance measurements ,021001 nanoscience & nanotechnology ,Chip ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Dielectric spectroscopy ,chemistry ,impedance-based biosensor ,gold nanoparticles ,surface characterization ,Colloidal gold ,Electrode ,Surface modification ,0210 nano-technology ,Biosensor ,Biomedical engineering - Abstract
With the increased practice of preventative healthcare to help reduce costs worldwide, sensor technology improvement is vital to patient care. Point-of-care (POC) diagnostics can reduce time and lower labor in testing, and can effectively avoid transporting costs because of portable designs. Label-free detection allows for greater versatility in the detection of biological molecules. Here, we describe the use of an impedance-based POC biosensor that can detect changes in the surface modification of a micro-fabricated chip using impedance spectroscopy. Gold nanoparticles (GNPs) have been employed to evaluate the sensing ability of our new chip using impedance measurements. Furthermore, we used impedance measurements to monitor surface functionalization progress on the sensor’s interdigitated electrodes (IDEs). Electrodes made from aluminum and gold were employed and the results were analyzed to compare the impact of electrode material. GNPs coated with mercaptoundecanoic acid were also used as a model of biomolecules to greatly enhance chemical affinity to the silicon substrate. The portable sensor can be used as an alternative technology to ELISA (enzyme-linked immunosorbent assays) and polymerase chain reaction (PCR)-based techniques. This system has advantages over PCR and ELISA both in the amount of time required for testing and the ease of use of our sensor. With other techniques, larger, expensive equipment must be utilized in a lab environment, and procedures have to be carried out by trained professionals. The simplicity of our sensor system can lead to an automated and portable sensing system.
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- 2017
18. Role of the Genes of Type VI Secretion System in Virulence of Rice Bacterial Brown Stripe Pathogen Acidovorax avenae subsp. avenae Strain RS-2
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Yang Zhang, Yushi Fang, Guochang Sun, Md. Mahidul Islam Masum, Jie Chen, Wen Qiu, Yanli Wang, Bin Li, Yingzi Yang, and Ogunyemi Solabomi Olaitan
- Subjects
0301 basic medicine ,Iron-Sulfur Proteins ,gene knock-out ,Mutant ,Acidovorax avenae subsp. Avenae ,biofilm ,lcsh:Chemistry ,Gene cluster ,pathogenicity ,Pathogen ,lcsh:QH301-705.5 ,Spectroscopy ,Virulence ,Acidovorax ,Hcp ,General Medicine ,Type VI Secretion Systems ,Computer Science Applications ,Anti-Bacterial Agents ,Complementation ,T6SS ,motility ,Multigene Family ,growth ,030106 microbiology ,Biology ,Catalysis ,Article ,Microbiology ,Inorganic Chemistry ,Comamonadaceae ,03 medical and health sciences ,Bacterial Proteins ,Secretion ,Physical and Theoretical Chemistry ,Molecular Biology ,Type VI secretion system ,Plant Diseases ,Organic Chemistry ,Genetic Complementation Test ,Oryza ,Gene Expression Regulation, Bacterial ,biology.organism_classification ,Mutagenesis, Insertional ,lcsh:Biology (General) ,lcsh:QD1-999 ,Biofilms ,Genome, Bacterial - Abstract
The Type VI secretion system (T6SS) is a class of macromolecular machine that is required for the virulence of gram-negative bacteria. However, it is still not clear what the role of T6SS in the virulence of rice bacterial brown stripe pathogen Acidovorax avenae subsp. avenae (Aaa) is. The aim of the current study was to investigate the contribution of T6SS in Aaa strain RS2 virulence using insertional deletion mutation and complementation approaches. This strain produced weak virulence but contains a complete T6SS gene cluster based on a genome-wide analysis. Here we compared the virulence-related phenotypes between the wild-type (RS-2) and 25 T6SS mutants, which were constructed using homologous recombination methods. The mutation of 15 T6SS genes significantly reduced bacterial virulence and the secretion of Hcp protein. Additionally, the complemented 7 mutations ΔpppA, ΔclpB, Δhcp, ΔdotU, ΔicmF, ΔimpJ, and ΔimpM caused similar virulence characteristics as RS-2. Moreover, the mutant ΔpppA, ΔclpB, ΔicmF, ΔimpJ and ΔimpM genes caused by a 38.3~56.4% reduction in biofilm formation while the mutants ΔpppA, ΔclpB, ΔicmF and Δhcp resulted in a 37.5~44.6% reduction in motility. All together, these results demonstrate that T6SS play vital roles in the virulence of strain RS-2, which may be partially attributed to the reductions in Hcp secretion, biofilm formation and motility. However, differences in virulence between strain RS-1 and RS-2 suggest that other factors may also be involved in the virulence of Aaa.
- Published
- 2017
19. Muscle Conditional Medium Reduces Intramuscular Adipocyte Differentiation and Lipid Accumulation through Regulating Insulin Signaling
- Author
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Ye Tian, Zaohang Jiang, Haiyin Han, Jie Chen, Wei Wei, Kaiqing Liu, and Weiwei Chu
- Subjects
0301 basic medicine ,Swine ,medicine.medical_treatment ,Apoptosis ,Receptor, IGF Type 1 ,lcsh:Chemistry ,extracellular micro-environment ,chemistry.chemical_compound ,Mice ,Adipocyte ,Adipocytes ,Insulin ,insulin receptor ,lcsh:QH301-705.5 ,Spectroscopy ,intramuscular preadipocytes ,Organelle Biogenesis ,Cell Differentiation ,General Medicine ,Computer Science Applications ,medicine.anatomical_structure ,Cellular Microenvironment ,Adipogenesis ,insulin-like growth factor 1 receptor ,Signal Transduction ,medicine.medical_specialty ,Biology ,Catalysis ,Article ,adipogenesis ,Inorganic Chemistry ,03 medical and health sciences ,Paracrine signalling ,Downregulation and upregulation ,Internal medicine ,3T3-L1 Cells ,Paracrine Communication ,medicine ,Animals ,Physical and Theoretical Chemistry ,Muscle, Skeletal ,Molecular Biology ,Cell Proliferation ,Growth factor ,Organic Chemistry ,Skeletal muscle ,Lipid metabolism ,porcine ,Lipid Metabolism ,Receptor, Insulin ,Insulin receptor ,030104 developmental biology ,Endocrinology ,chemistry ,lcsh:Biology (General) ,lcsh:QD1-999 ,Culture Media, Conditioned ,biology.protein - Abstract
Due to the paracrine effects of skeletal muscle, the lipid metabolism of porcine intramuscular (i.m.) preadipocytes was different from that of subcutaneous (s.c.) preadipocytes. To investigate the development of i.m. preadipocytes in vivo, the s.c. preadipocytes were cultured with muscle conditional cultured medium (MCM) for approximating extracellular micro-environment of the i.m. preadipocytes. Insulin signaling plays a fundamental role in porcine adipocyte differentiation. The expression levels of insulin receptor (INSR) and insulin-like growth factor 1 receptor (IGF-1R) in i.m. Preadipocytes were higher than that in s.c. preadipocytes. The effects of MCM on adipocyte differentiation, lipid metabolism and insulin signaling transdution were verified. MCM induced the apoptosis of s.c. preadipocytes but not of s.c. adipocytes. Moreover, MCM inhibited adipocyte differentiation at pre-differentiation and early stages of differentiation, while the expression levels of INSR and IGF-1R were increased. Furthermore, MCM treatment increased adipocyte lipolysis and fatty acid oxidation through induction of genes involved in lipolysis, thermogenesis, and fatty acid oxidation in mitochondria. Consistent with the above, treatment of s.c. adipocytes with MCM upregulated mitochondrial biogenesis. Taken together, MCM can approximate the muscle micro-environment and reduce intramuscular adipocyte differentiation and lipid accumulation via regulating insulin signaling.
- Published
- 2017
20. Comparison of the Cumulative Incidence Rates of Coal Workers’ Pneumoconiosis between 1970 and 2013 among Four State-Owned Colliery Groups in China
- Author
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Fuhai Shen, Tianbang Qin, Xia Suo, Jie Chen, Bing Han, Hongbo Liu, Kai Cui, and Juxiang Yuan
- Subjects
Male ,China ,State owned ,Health, Toxicology and Mutagenesis ,lcsh:Medicine ,Article ,Toxicology ,Stratified analysis ,Cohort Studies ,life-table method ,Occupational Exposure ,medicine ,Humans ,Dust exposure ,Coal ,Cumulative incidence ,Life Tables ,Anthracosis ,coal workers’ pneumoconiosis ,business.industry ,Incidence (epidemiology) ,Pneumoconiosis ,Incidence ,lcsh:R ,Ownership ,Public Health, Environmental and Occupational Health ,Coal mining ,Dust ,medicine.disease ,Coal Mining ,business ,cumulative incidence rate - Abstract
The purpose of this study was to identify differences in the incidence characteristics of coal workers’ pneumoconiosis (CWP) based on data from four large state-owned colliery groups of China, by comparing the cumulative incidence rates of CWP. We investigated 87,904 coal workers from the Datong, Kailuan, Fuxin, and Tiefa Colliery Groups, who were exposed to dust for at least 1 year. The cumulative incidence rate of CWP was calculated with the life-table method and stratified analysis among coal workers with different occupational categories during different years of first dust exposure. Our results showed the cumulative incidence rate of Datong was higher than that of any other colliery group among workers with different occupational categories during different years of first dust exposure. For Datong workers who started their dust exposure in the 1970s, the cumulative incidence rates of CWP among tunneling, mining, combining, and helping workers were 34.77%, 10.20%, 34.59%, and 4.91% during the observed time of 34 years, respectively. For those in the 1980s, the cumulative incidence rates were 32.29%, 13.51%, 2.98%, and 0.47%, respectively. The cumulative incidence rates of Fuxin and Tiefa were the lowest. In conclusion, the Datong colliery has the highest cumulative incidence rate of CWP among the four studied collieries, followed by Kailuan. The cumulative incidence rates of Fuxin and Tiefa were the lowest. Additional dust-proofing measures for decreasing dust concentrations are still necessary.
- Published
- 2015
21. Early Electronic Screen Exposure and Autistic-Like Behaviors among Preschoolers: The Mediating Role of Caregiver-Child Interaction, Sleep Duration and Outdoor Activities.
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Jing-Yi Chen, Strodl, Esben, Li-Hua Huang, Ying-Jie Chen, Gui-You Yang, and Wei-Qing Chen
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PRESCHOOL children ,AUTISTIC children ,CAREGIVERS ,SLEEP ,MEDIATION - Abstract
Research into early screen exposure has raised growing concerns about its impact upon children's neuropsychological well-being. However, possible pathways remain unclear. This study therefore aimed not only to evaluate the association between screen exposure during the ages of 0-3 years and preschoolers' autistic-like behaviors, but also the mediating roles of the frequency of caregiver-child interaction, sleep duration and level of participation in outdoor activities. Based on the 2017 survey of the Longhua Child Cohort Study, data of 29,595 child-caregiver dyads were obtained via a caregiver-reported questionnaire, with the data from 29,461 dyads included in the data analysis. Multiple linear and logistic regression models were employed to estimate the associations between screen exposure, caregiver-child interaction, sleep duration, outdoor activities, and children's autistic-like behaviors. The results indicated that screen exposure during 0-3 years of age was associated with the presence of autistic-like behaviors at preschool age, and the strength of the association was enhanced with the increase of average daily screen time (Odds Ratios (ORs) ranging from 1.358 to 4.026). The frequency of caregiver-child interaction and sleep duration mediated 5.32% and 1.19% of the variance of the association respectively, but outdoor activities did not mediate the association. Our findings indicate that preschoolers who are exposed to screens at aged 0-3 years might have an increased risk of autistic-like behaviors, and that, the frequency of caregiver-child interaction and sleep duration might function as potential mediators of this association. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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22. An NN-Based SRD Decomposition Algorithm and Its Application in Nonlinear Compensation
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Sun Jian, Yan Honghang, Jie Chen, and Fang Deng
- Subjects
decomposition algorithm ,Artificial neural network ,nonlinear errors compensation ,Computer science ,Fourier neural network ,lcsh:Chemical technology ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Article ,Analytical Chemistry ,data amount ,Nonlinear system ,Square root ,Decomposition method (queueing theory) ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,Encoder ,Algorithm - Abstract
In this study, a neural network-based square root of descending (SRD) order decomposition algorithm for compensating for nonlinear data generated by sensors is presented. The study aims at exploring the optimized decomposition of data 1.00,0.00,0.00 and minimizing the computational complexity and memory space of the training process. A linear decomposition algorithm, which automatically finds the optimal decomposition N and reduces the training time to 1 N and memory cost to 1 N , has been implemented on nonlinear data obtained from an encoder. Particular focus is given to the theoretical access of estimating the numbers of hidden nodes and the precision of varying the decomposition method. Numerical experiments are designed to evaluate the effect of this algorithm. Moreover, a designed device for angular sensor calibration is presented. We conduct an experiment that samples the data of an encoder and compensates for the nonlinearity of the encoder to testify this novel algorithm.
- Published
- 2014
23. High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF
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Yue Fang, Wei Liu, Zhirong Men, Chunsheng Li, Jie Chen, and Pengbo Wang
- Subjects
Pulse repetition frequency ,Synthetic aperture radar ,010504 meteorology & atmospheric sciences ,Computer science ,Beam steering ,0211 other engineering and technologies ,high-temporal-resolution ,02 engineering and technology ,lcsh:Chemical technology ,01 natural sciences ,Biochemistry ,Article ,Analytical Chemistry ,Data acquisition ,high-spatial-resolution ,high-squint-angle ,synthetic aperture radar (SAR) ,continuously varying PRF (CVPRF) ,high-order imaging algorithm ,Staring ,Nadir ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Echo (computing) ,Slant range ,Atomic and Molecular Physics, and Optics - Abstract
Synthetic Aperture Radar (SAR) is a well-established and powerful imaging technique for acquiring high-spatial-resolution images of the Earth’s surface. With the development of beam steering techniques, sliding spotlight and staring spotlight modes have been employed to support high-spatial-resolution applications. In addition to this strengthened high-spatial-resolution and wide-swath capability, high-temporal-resolution (short repeat-observation interval) represents a key capability for numerous applications. However, conventional SAR systems are limited in that the same patch can only be illuminated for several seconds within a single pass. This paper considers a novel high-squint-angle system intended to acquire high-spatial-resolution spaceborne SAR images with repeat-observation intervals varying from tens of seconds to several minutes within a single pass. However, an exponentially increased range cell migration would arise and lead to a conflict between the receive window and ‘blind ranges’. An efficient data acquisition technique for high-temporal-resolution, high-spatial-resolution and high-squint-angle spaceborne SAR, in which the pulse repetition frequency (PRF) is continuously varied according to the changing slant range, is presented in this paper. This technique allows echo data to remain in the receive window instead of conflicting with the transmitted pulse or nadir echo. Considering the precision of hardware, a compromise and practical strategy is also proposed. Furthermore, a detailed performance analysis of range ambiguities is provided with respect to parameters of TerraSAR-X. For strong point-like targets, the range ambiguity of this technique would be better than that of uniform PRF technique. For this innovative technique, a resampling strategy and modified imaging algorithm have been developed to handle the non-uniformly sampled echo data. Simulations are performed to validate the efficiency of the proposed technique and the associated imaging algorithm.
- Published
- 2017
24. High-Performance Anti-Retransmission Deception Jamming Utilizing Range Direction Multiple Input and Multiple Output (MIMO) Synthetic Aperture Radar (SAR)
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Jie Chen, Ruijia Wang, Xing Wang, and Bing Sun
- Subjects
Synthetic aperture radar ,Signal-to-interference ratio ,Computer science ,Orthogonal frequency-division multiplexing ,Retransmission ,MIMO ,0211 other engineering and technologies ,sub-band synthesize ,Jamming ,02 engineering and technology ,lcsh:Chemical technology ,Biochemistry ,Signal ,Article ,range direction ,Analytical Chemistry ,SAR ,jamming suppression ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,021101 geological & geomatics engineering ,Computer Science::Information Theory ,fungi ,020206 networking & telecommunications ,Atomic and Molecular Physics, and Optics ,Amplitude ratio ,Transmission (telecommunications) ,Radar jamming and deception ,Frequency modulation ,Communication channel - Abstract
Retransmission deception jamming seriously degrades the Synthetic Aperture Radar (SAR) detection efficiency and can mislead SAR image interpretation by forming false targets. In order to suppress retransmission deception jamming, this paper proposes a novel multiple input and multiple output (MIMO) SAR structure range direction MIMO SAR, whose multiple channel antennas are vertical to the azimuth. First, based on the multiple channels of range direction MIMO SAR, the orthogonal frequency division multiplexing (OFDM) linear frequency modulation (LFM) signal was adopted as the transmission signal of each channel, which is defined as a sub-band signal. This sub-band signal corresponds to the transmission channel. Then, all of the sub-band signals are modulated with random initial phases and concurrently transmitted. The signal form is more complex and difficult to intercept. Next, the echoes of the sub-band signal are utilized to synthesize a wide band signal after preprocessing. The proposed method will increase the signal to interference ratio and peak amplitude ratio of the signal to resist retransmission deception jamming. Finally, well-focused SAR imagery is obtained using a conventional imaging method where the retransmission deception jamming strength is degraded and defocused. Simulations demonstrated the effectiveness of the proposed method.
- Published
- 2017
25. A Wide-Swath Spaceborne TOPS SAR Image Formation Algorithm Based on Chirp Scaling and Chirp-Z Transform
- Author
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Jie Chen, Wei Liu, Hong Cheng Zeng, Peng Bo Wang, and Wei Yang
- Subjects
Image formation ,SAR ,TOPS ,modified azimuth deramp ,chirp-z ,Computer science ,Bluestein's FFT algorithm ,0211 other engineering and technologies ,02 engineering and technology ,lcsh:Chemical technology ,Biochemistry ,Signal ,Article ,Analytical Chemistry ,Reduction (complexity) ,Aliasing ,0202 electrical engineering, electronic engineering, information engineering ,Computer vision ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,021101 geological & geomatics engineering ,business.industry ,020206 networking & telecommunications ,Atomic and Molecular Physics, and Optics ,Artificial intelligence ,Antenna (radio) ,business ,Algorithm ,Interpolation - Abstract
Based on the terrain observation by progressive scans (TOPS) mode, an efficient\ud full-aperture image formation algorithm for focusing wide-swath spaceborne TOPS data is proposed.\ud First, to overcome the Doppler frequency spectrum aliasing caused by azimuth antenna steering,\ud the range-independent derotation operation is adopted, and the signal properties after derotation\ud are derived in detail. Then, the azimuth deramp operation is performed to resolve image folding\ud in azimuth. The traditional dermap function will introduce a time shift, resulting in appearance\ud of ghost targets and azimuth resolution reduction at the scene edge, especially in the wide-swath\ud coverage case. To avoid this, a novel solution is provided using a modified range-dependent deramp\ud function combined with the chirp-z transform. Moreover, range scaling and azimuth scaling are\ud performed to provide the same azimuth and range sampling interval for all sub-swaths, instead of the\ud interpolation operation for the sub-swath image mosaic. Simulation results are provided to validate\ud the proposed algorithm.
- Published
- 2016
26. Riverine Sediment Geochemistry as Provenance Fingerprints along the Eastern Coast of China: Constraint, Approach, and Application.
- Author
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Jie Chen, Ping Liu, Dandan Sun, Dan Zhang, Bingdi Miao, and Jing Chen
- Subjects
- *
GEOCHEMISTRY , *RIVER sediments , *SEDIMENTS , *GEOCHEMICAL modeling , *COASTS - Abstract
Sediment geochemistry is affected by sediment granularity and chemical partition, which may greatly influence the accuracy of sediment source identification. In this study, we analyzed Ca, Co, Zr, V, Cr, Ti, Sc, Th, and Al in the sediments of major rivers and a Holocene core along the eastern coast of China to reveal the constraints on sediment geochemistry related to granularity and chemical partition and to try and identify the sources of the sediments present in the core. The results reveal that the element concentrations have a significant positive correlation with Al concentration in all these riverine sediments. There are significant differences in the element contents of the bulk sample and the residual sediment leached with acid, including in their ratios. The ratios of Cr/Th-Sc/Th, which is often used for provenance discrimination, reveal that uncertainty of provenance discrimination will increase if the impact of sediment granularity and chemical phase on the index system is not considered. We applied this geochemical approach for provenance on a Holocene core of the East China Sea using Cr/Th-Al, Sc/Th-Al, Ti/Zr-Al, and Cr/Th-Sc/Th with the same granularity as the residue sediments. Based on this approach, we identified the core sediments to have had a large component derived from the western Taiwanese rivers since the mid-Holocene. This study sheds light on the sediment geochemistry used to identify the provenance of marginal seas with multiple rivers entering them. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
27. Trehalose Alleviates Crystalline Silica-Induced Pulmonary Fibrosis via Activation of the TFEB-Mediated Autophagy-Lysosomal System in Alveolar Macrophages.
- Author
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Xiu He, Shi Chen, Chao Li, Jiaqi Ban, Yungeng Wei, Yangyang He, Fangwei Liu, Ying Chen, and Jie Chen
- Subjects
ALVEOLAR macrophages ,PULMONARY fibrosis ,LYSOSOMES ,TREHALOSE ,AUTOPHAGY ,LUNG diseases ,OCCUPATIONAL diseases - Abstract
Silicosis is an occupational lung disease characterized by persistent inflammation and irreversible fibrosis. Crystalline silica (CS) particles are mainly phagocytized by alveolar macrophages (AMs), which trigger apoptosis, inflammation, and pulmonary fibrosis. Previously, we found that autophagy-lysosomal system dysfunction in AMs was involved in CS-induced inflammation and fibrosis. Induction of autophagy and lysosomal biogenesis by transcription factor EB (TFEB) nuclear translocation can rescue fibrotic diseases. However, the role of TFEB in silicosis is unknown. In this study, we found that CS induced TFEB nuclear localization and increased TFEB expression in macrophages both in vivo and in vitro. However, TFEB overexpression or treatment with the TFEB activator trehalose (Tre) alleviated lysosomal dysfunction and enhanced autophagic flux. It also reduced apoptosis, inflammatory cytokine levels, and fibrosis. Both pharmacologically inhibition of autophagy and TFEB knockdown in macrophages significantly abolished the antiapoptotic and anti-inflammatory effects elicited by either TFEB overexpression or Tre treatment. In conclusion, these results uncover a protective role of TFEB-mediated autophagy in silicosis. Our study suggests that restoration of autophagy-lysosomal function by Tre-induced TFEB activation may be a novel strategy for the treatment of silicosis. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
28. A Novel Method of Multi-Information Acquisition for Electromagnetic Flow Meters
- Author
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Bin Li, Li Xinwei, Jie Chen, and Cui Wenhua
- Subjects
Materials science ,Acoustics ,electromagnetic flow meter ,multi-information ,electrical excitation ,impedance spectroscopy ,multi-frequency synchronous signal ,photovoltaic cell ,lcsh:Chemical technology ,Biochemistry ,Capacitance ,Article ,Analytical Chemistry ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,Electrical impedance ,Observational error ,Magnetic flow meter ,Atomic and Molecular Physics, and Optics ,Dielectric spectroscopy ,Transducer ,Flow velocity ,Electrode ,Biomedical engineering - Abstract
In this paper, a novel method is proposed for multi-information acquisition from the electromagnetic flow meter, using magnetic excitation to measure the fluid velocity and electrochemistry impedance spectroscopy (EIS) for both the fluid quality and the contamination level of the transducer. The impedance spectra of the transducer are measured with an additional electrical stimulus in series with the electrode measurement loop. The series connection mode instead of the parallel one improves the signal-to-noise ratio (SNR) of the fluid velocity measurement and offers a wide range of impedance measurements by using a sample capacitance. In addition, a multi-frequency synchronous excitation source is synthesized based on the method of dual-base power sequences for fast EIS measurement. The conductivity measurements in the range of 1.7 μS/cm–2 mS/cm showed a relatively high accuracy with a measurement error of 5%, and the electrode adhesion detection on both with coating and no coating showed the ability of the qualitative determination of the electrode adhesion, which validated the feasibility of the multi-information acquisition method for the electromagnetic flow meter (EMFM).
- Published
- 2015
29. STUDY OF A PASSIVE MICROMIXER BASED ON ASKEW CORRUGATED MICROCHANNEL
- Author
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Jie, Chen, primary
- Published
- 2017
- Full Text
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30. Concentration Generator With On Chip Vacuum Pump
- Author
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Jie, Chen, primary
- Published
- 2017
- Full Text
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31. A washboard-type passive micromixer
- Author
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Jie, Chen, primary
- Published
- 2017
- Full Text
- View/download PDF
32. Modified Omega-k Algorithm for High-Speed Platform Highly-Squint Staggered SAR Based on Azimuth Non-Uniform Interpolation
- Author
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Jie Chen, Wei Yang, Wei Liu, and Zeng Hongcheng
- Subjects
Pulse repetition frequency ,Computer science ,Phase (waves) ,Residual ,lcsh:Chemical technology ,Biochemistry ,Article ,Analytical Chemistry ,symbols.namesake ,Sampling (signal processing) ,Computer Simulation ,lcsh:TP1-1185 ,staggered SAR ,Electrical and Electronic Engineering ,Instrumentation ,modified Omega-k ,Models, Theoretical ,azimuth non-uniform sampling (ANS) ,continuous PRI variation ,Atomic and Molecular Physics, and Optics ,Strabismus ,Azimuth ,Earth Sciences ,symbols ,Baseband ,Focus (optics) ,Doppler effect ,Algorithm ,Algorithms ,Interpolation - Abstract
In this work, the staggered SAR technique is employed for high-speed platform highly-squint SAR by varying the pulse repetition interval (PRI) as a linear function of range-walk. To focus the staggered SAR data more efficiently, a low-complexity modified Omega-k algorithm is proposed based on a novel method for optimal azimuth non-uniform interpolation, avoiding zero padding in range direction for recovering range cell migration (RCM) and saving in both data storage and computational load. An approximate model on continuous PRI variation with respect to sliding receive-window is employed in the proposed algorithm, leaving a residual phase error only due to the effect of a time-varying Doppler phase caused by staggered SAR. Then, azimuth non-uniform interpolation (ANI) at baseband is carried out to compensate the azimuth non-uniform sampling (ANS) effect resulting from continuous PRI variation, which is further followed by the modified Omega-k algorithm. The proposed algorithm has a significantly lower computational complexity, but with an equally effective imaging performance, as shown in our simulation results.
- Published
- 2015
33. Development, Characterization, and Validation of a Cold Stage-Based Ice Nucleation Array (PKU-INA).
- Author
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Jie Chen, Xiangyu Pei, Hong Wang, Jingchuan Chen, Yishu Zhu, Mingjin Tang, and Zhijun Wu
- Subjects
- *
ICE nuclei , *ATMOSPHERIC nucleation , *METEOROLOGICAL precipitation , *FREEZING , *DROP size distribution - Abstract
A drop-freeze array (PeKing University Ice Nucleation Array, PKU-INA) was developed based on the cold-stage method to investigate heterogeneous ice nucleation properties of atmospheric particles in the immersion freezing mode from -30 to 0 °C. The instrumental details as well as characterization and performance evaluation are described in this paper. A careful temperature calibration protocol was developed in our work. The uncertainties in the reported temperatures were found to be less than 0.4 °C at various cooling rates after calibration. We also measured the ice nucleation activities of droplets containing different mass concentrations of illite NX, and the results obtained in our work show good agreement with those reported previously using other instruments with similar principles. Overall, we show that our newly developed PKU-INA is a robust and reliable instrument for investigation of heterogeneous ice nucleation in the immersion freezing mode. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
34. Experimental Demonstration of Remote and Compact Imaging Spectrometer Based on Mobile Devices.
- Author
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Jie Chen, Fuhong Cai, Rongxiao He, and Sailing He
- Abstract
Imaging spectrometers show great potential for environmental and biomedical sensing applications. Selfie sticks, which are tools used to take photographs or videos, have gained global popularity in recent years. Few people have connected these two objects, and few people have researched the application of imaging spectrometers to perform scientific monitoring in point-of-use scenarios. In this paper, we develop a compact imaging spectrometer (35 g in weight, 18 mm in diameter, and 72 mm in length) that can be equipped on a motorized selfie stick to perform remote sensing. We applied this system to perform environmental and facial remote sensing via motorized scanning. The absorption of chlorophyll and hemoglobin can be found in the reflectance spectra, indicating that our system can be used in urban greening monitoring and point-of-care testing. In addition, this compact imaging spectrometer was also easily attached to an underwater dome port and a quad-rotor unmanned aerial vehicle to perform underwater and airborne spectral detection. Our system offers a route toward mobile imaging spectrometers used in daily life. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
35. Synthesis and Properties of a Novel Environmental Epoxidized Glycidyl Ester of Ricinoleic Acetic Ester Plasticizer for Poly(vinyl chloride).
- Author
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Jie Chen, Ke Li, Yigang Wang, Jinrui Huang, Xiaoan Nie, and Jianchun Jiang
- Subjects
- *
VINYL chloride , *CHLORIDES , *ALKOXY compounds , *ESTERS , *CHEMICAL synthesis , *CARBOXYLIC acids - Abstract
A novel renewable plasticizer based on castor oil, epoxidized glycidyl ester of ricinoleic acetic ester (EGERAE), was synthesized and applied into Poly(vinyl chloride) (PVC) for the first time. Its molecular structure was characterized by FT-IR and 1H NMR. The effects of replacement of petroleum-based commercial plasticizer dioctyl phthalate (DOP) with EGERAE in poly(vinyl chloride) (PVC) films were researched. Thermal stability, dynamic mechanical property and mechanical properties of PVC films were investigated with thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and tensile tests. The results indicated that this castor oil-based plasticizer was able to improve the thermal stability of PVC blends when partially of completely substituting for DOP. Furthermore, EGERAE endowed PVC resin with enhanced flexibility. In addition, the exudation, volatility and extraction resistance characteristics of plasticizers were researched. The degradation mechanism and possible interaction between EGERAE and PVCmolecules in the plasticized systemwere also investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
36. Research on Pulsed Jet Flow Control without External Energy in a Blade Cascade.
- Author
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Jie Chen, Weiyu Lu, Guoping Huang, Jianfeng Zhu, and Jinchun Wang
- Subjects
- *
JETS (Fluid dynamics) , *FLOW separation , *PROPER orthogonal decomposition , *KINETIC energy , *FLOW control (Data transmission systems) - Abstract
To control the flow separation in the compressors, a novel pulsed jet concept without external energy injection is proposed. The new concept designs a slot in the middle of the blade and sets a micro device to switch the slot periodically. Such a structure is expected to generate a pulsed jet by the pressure difference between the pressure side and the suction side of the blade. In order to analyze the interaction between the pulsed jet and unsteady separated flow, our numerical and experimental study is based on a specific cascade (with a flow separation inside) and a pulsed jet (one of the unsteady flow control method). The experimental and numerical results both show that when the frequency of pulsed jet is approximate to that of the separation vortex, then the control tends to be more effective. Based on the numerical simulations, the proper orthogonal decomposition (POD) is then used to reveal the control mechanism, extracting the different time-space structures from the original field. The results with the aid of POD show that the pulsed jet can redistribute the kinetic energy of each mode, and strengthen or weaken certain modes, particularly, while the steady jet reduces the kinetic energy of high-order modes in whole. Also, pulsed jet with proper parameters can transfer the energy from higher modes to the first flow mode (averaged flow), which is due to the conversion of the spatial vortical structures and the time evolution of the modes. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
37. Conflicting Information Fusion Based on an Improved DS Combination Method.
- Author
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Jie Chen, Fang Ye, Tao Jiang, and Yuan Tian
- Subjects
- *
DEMPSTER-Shafer theory , *PROBABILITY theory , *DISCRETE choice models , *MULTISENSOR data fusion , *IMAGE fusion - Abstract
An effective and reliable fusion method for conflicting information is proposed in this paper. Compared with a single-sensor system, a multi-sensor fusion system can comprehensively combine the redundancy and complementarity of multi-sensor information to obtain better system performance. Hence, the multi-sensor fusion system has become one of the research hotspots. However, due to lack knowledge about the measurement environment and limited sensor accuracy, the multi-sensor system inevitably appears to have imperfect, uncertain and inconsistent information. To solve the problem, we introduce one powerful uncertainty reasoning method: Dempster-Shafer theory (DS theory). With convincing measurement and a forceful combination of uncertain information, DS theory is widely applied in various fields, like decision-making, expert systems, target tracking, monitoring systems, etc. Nevertheless, DS theory will produce counter-intuitive fusion results when the pieces of evidence are highly conflicting. To address this issue, we raise an improved DS combination method for conflicting information fusion in this paper. First of all, the modified Minkowski distance function and the betting-commitment distance function are separately employed to revise potentially conflicting pieces of evidence. The procedure availably solves the conflicting situations caused by unreliable and imprecise evidence sources, which enhances the consistency among pieces of evidence. Then, based on two revised pieces of evidence, a conflicting redistribution strategy based on locally conflicting analyses is put forward. The approach dexterously combines two revised pieces of evidence to avoid conflicting situations caused by compulsive normalization, which further improves the accuracy and convergence speed of the multi-sensor fusion system. Finally, two experimental analyses with consistent information and conflicting information reveal the remarkable effectiveness and priority of the proposed algorithm for the multi-sensor fusion system. Consequently, this paper has certain value for the multi-sensor fusion system. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
38. Encapsulation Mechanism of Oxyresveratrol by β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin and Computational Analysis.
- Author
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Jianfei He, Zong-Ping Zheng, Qin Zhu, Fengxian Guo, and Jie Chen
- Subjects
RESVERATROL ,CYCLODEXTRINS ,STOICHIOMETRY ,MOLECULAR docking ,MOLECULAR models - Abstract
In this study, the encapsulation mechanism of oxyresveratrol and β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) was studied. As this research shows, oxyresveratrol and two cyclodextrins (CDs) were able to form inclusion complexes in a 1:1 stoichiometry. However, the interaction with HP-β-CD was more efficient, showing up as higher encapsulation constant (KF) (35,864.72 ± 3415.89 M
-1 ). The KF values exhibited a strong dependence on temperature and pH, which decreased as they increased. From the thermodynamic parameters (ΔH0 , ΔS0 , and ΔG0 ) of the oxyresveratrol loaded β-CD (oxyresveratrol-β-CD) and HP-β-CD (oxyresveratrol-HP-β-CD), it could be seen that the complexation process was spontaneous and exothermic, and the main driving forces between oxyrsveratrol and CDs were hydrogen bonding and van der waals force. Besides, molecular docking combined with ¹H-NMR were used to explain the most possible mode of interactions between oxyresveratrol and CDs. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
39. Role of the Genes of Type VI Secretion System in Virulence of Rice Bacterial Brown Stripe Pathogen Acidovorax avenae subsp. avenae Strain RS-2.
- Author
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Md. Mahidul Islam Masum, Yingzi Yang, Bin Li, Ogunyemi Solabomi Olaitan, Jie Chen, Yang Zhang, Yushi Fang, Wen Qiu, Yanli Wang, and Guochang Sun
- Subjects
GRAM-negative bacteria ,VIRULENCE of bacteria ,RICE diseases & pests ,DELETION mutation ,BACTERIAL mutation ,BACTERIAL growth ,BIOFILMS ,PHENOTYPES ,BACTERIAL genetics - Abstract
The Type VI secretion system (T6SS) is a class of macromolecular machine that is required for the virulence of gram-negative bacteria. However, it is still not clear what the role of T6SS in the virulence of rice bacterial brown stripe pathogen Acidovorax avenae subsp. avenae (Aaa) is. The aim of the current study was to investigate the contribution of T6SS in Aaa strain RS2 virulence using insertional deletion mutation and complementation approaches. This strain produced weak virulence but contains a complete T6SS gene cluster based on a genome-wide analysis. Here we compared the virulence-related phenotypes between the wild-type (RS-2) and 25 T6SS mutants, which were constructed using homologous recombination methods. The mutation of 15 T6SS genes significantly reduced bacterial virulence and the secretion of Hcp protein. Additionally, the complemented 7 mutations ΔpppA, ΔclpB, Δhcp, ΔdotU, ΔicmF, ΔimpJ, and ΔimpM caused similar virulence characteristics as RS-2. Moreover, the mutant ΔpppA, ΔclpB, ΔicmF, ΔimpJ and ΔimpM genes caused by a 38.3~56.4% reduction in biofilm formation while the mutants ΔpppA, ΔclpB, ΔicmF and Δhcp resulted in a 37.5~44.6% reduction in motility. All together, these results demonstrate that T6SS play vital roles in the virulence of strain RS-2, which may be partially attributed to the reductions in Hcp secretion, biofilm formation and motility. However, differences in virulence between strain RS-1 and RS-2 suggest that other factors may also be involved in the virulence of Aaa. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
40. Using Impedance Measurements to Characterize Surface Modified with Gold Nanoparticles.
- Author
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MacKay, Scott, Abdelrasoul, Gaser N., Tamura, Marcus, Donghai Lin, Zhimin Yan, and Jie Chen
- Abstract
With the increased practice of preventative healthcare to help reduce costs worldwide, sensor technology improvement is vital to patient care. Point-of-care (POC) diagnostics can reduce time and lower labor in testing, and can effectively avoid transporting costs because of portable designs. Label-free detection allows for greater versatility in the detection of biological molecules. Here, we describe the use of an impedance-based POC biosensor that can detect changes in the surface modification of a micro-fabricated chip using impedance spectroscopy. Gold nanoparticles (GNPs) have been employed to evaluate the sensing ability of our new chip using impedance measurements. Furthermore, we used impedance measurements to monitor surface functionalization progress on the sensor’s interdigitated electrodes (IDEs). Electrodes made from aluminum and gold were employed and the results were analyzed to compare the impact of electrode material. GNPs coated with mercaptoundecanoic acid were also used as a model of biomolecules to greatly enhance chemical affinity to the silicon substrate. The portable sensor can be used as an alternative technology to ELISA (enzyme-linked immunosorbent assays) and polymerase chain reaction (PCR)-based techniques. This system has advantages over PCR and ELISA both in the amount of time required for testing and the ease of use of our sensor. With other techniques, larger, expensive equipment must be utilized in a lab environment, and procedures have to be carried out by trained professionals. The simplicity of our sensor system can lead to an automated and portable sensing system. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
41. Feature Selection Solution with High Dimensionality and Low-Sample Size for Land Cover Classification in Object-Based Image Analysis.
- Author
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Yaohuan Huang, Chuanpeng Zhao, Haijun Yang, Xiaoyang Song, Jie Chen, and Zhonghua Li
- Subjects
LAND cover ,IMAGE analysis ,REMOTE sensing ,PARTIAL least squares regression ,RANDOM forest algorithms - Abstract
Land cover information extraction through object-based image analysis (OBIA) has become an important trend in remote sensing, thanks to the increasing availability of high-resolution imagery. Segmented objects have a large number of features that cause high-dimension and low-sample size problems in the classification process. In this study, on the basis of a partial least squares generalized linear regression (PLSGLR), we propose a group corrected PLSGLR, known as G-PLSGLR, that aims to reduce the redundancy of object features for land cover identifications. Using Gaofen-2 images, the area of interest was segmented and sampled to generate small sample-size training datasets with 51 object features. The features selected by G-PLSGLR were compared against a guided regularized random forest (GRRF) in metrics of reduction rate, feature redundancy, and accuracy assessment of classification. Three indicators of overall accuracy (OA), user's accuracy (UA), and producer's accuracy (PA) were applied for accuracy assessment in this paper. The result shows that the G-PLSGLR achieved a reduction rate of 9.27 with a feature redundancy of 0.29, and a value of OA 90.63%. The GRRF achieved a reduction rate of 1.61 with a feature redundancy of 0.42, and a value of OA 85.56%. The PA of each land cover category was more than 95% using features selected by G-PLSGLR, while the PA ranged from 77 to 96% using features selected by GRRF. The UA of G-PLSGLR-selected features ranged from 70 to 80% except for grass land and bare land, which achieved 10% higher UA than GRRF-selected features. The G-PLSGLR method we proposed has the advantages of a large reduction rate, low feature redundancy, and high classification performance, which can be applied in OBIA-based land cover classification. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
42. High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF.
- Author
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Zhirong Men, Pengbo Wang, Chunsheng Li, Jie Chen, Wei Liu, and Yue Fang
- Subjects
WINDOW blinds ,BLINDS manufacturing ,CELL migration ,SYNTHETIC apertures ,IMAGING systems - Abstract
Synthetic Aperture Radar (SAR) is a well-established and powerful imaging technique for acquiring high-spatial-resolution images of the Earth's surface. With the development of beam steering techniques, sliding spotlight and staring spotlight modes have been employed to support high-spatial-resolution applications. In addition to this strengthened high-spatial-resolution and wide-swath capability, high-temporal-resolution (short repeat-observation interval) represents a key capability for numerous applications. However, conventional SAR systems are limited in that the same patch can only be illuminated for several seconds within a single pass. This paper considers a novel high-squint-angle system intended to acquire high-spatial-resolution spaceborne SAR images with repeat-observation intervals varying from tens of seconds to several minutes within a single pass. However, an exponentially increased range cell migration would arise and lead to a conflict between the receive window and 'blind ranges'. An efficient data acquisition technique for high-temporal-resolution, high-spatial-resolution and high-squint-angle spaceborne SAR, in which the pulse repetition frequency (PRF) is continuously varied according to the changing slant range, is presented in this paper. This technique allows echo data to remain in the receive window instead of conflicting with the transmitted pulse or nadir echo. Considering the precision of hardware, a compromise and practical strategy is also proposed. Furthermore, a detailed performance analysis of range ambiguities is provided with respect to parameters of TerraSAR-X. For strong point-like targets, the range ambiguity of this technique would be better than that of uniform PRF technique. For this innovative technique, a resampling strategy and modified imaging algorithm have been developed to handle the non-uniformly sampled echo data. Simulations are performed to validate the efficiency of the proposed technique and the associated imaging algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
43. Muscle Conditional Medium Reduces Intramuscular Adipocyte Differentiation and Lipid Accumulation through Regulating Insulin Signaling.
- Author
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Haiyin Han, Wei Wei, Weiwei Chu, Kaiqing Liu, Ye Tian, Zaohang Jiang, and Jie Chen
- Subjects
PARACRINE mechanisms ,CELLULAR control mechanisms ,SKELETAL muscle ,LIPID metabolism ,INSULIN receptors - Abstract
Due to the paracrine effects of skeletal muscle, the lipid metabolism of porcine intramuscular (i.m.) preadipocytes was different from that of subcutaneous (s.c.) preadipocytes. To investigate the development of i.m. preadipocytes in vivo, the s.c. preadipocytes were cultured with muscle conditional cultured medium (MCM) for approximating extracellular micro-environment of the i.m. preadipocytes. Insulin signaling plays a fundamental role in porcine adipocyte differentiation. The expression levels of insulin receptor (INSR) and insulin-like growth factor 1 receptor (IGF-1R) in i.m. Preadipocytes were higher than that in s.c. preadipocytes. The effects of MCM on adipocyte differentiation, lipid metabolism and insulin signaling transdution were verified. MCM induced the apoptosis of s.c. preadipocytes but not of s.c. adipocytes. Moreover, MCM inhibited adipocyte differentiation at pre-differentiation and early stages of differentiation, while the expression levels of INSR and IGF-1R were increased. Furthermore, MCM treatment increased adipocyte lipolysis and fatty acid oxidation through induction of genes involved in lipolysis, thermogenesis, and fatty acid oxidation in mitochondria. Consistent with the above, treatment of s.c. adipocytes with MCM upregulated mitochondrial biogenesis. Taken together, MCM can approximate the muscle micro-environment and reduce intramuscular adipocyte differentiation and lipid accumulation via regulating insulin signaling. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
44. CFD-PBM Approach with Different Inlet Locations for the Gas-Liquid Flow in a Laboratory-Scale Bubble Column with Activated Sludge/Water.
- Author
-
Le Wang, Qiang Pan, Jie Chen, and Shunsheng Yang
- Subjects
COMPUTATIONAL fluid dynamics ,ACTIVATED sludge process ,HYDRODYNAMICS ,NON-Newtonian flow (Fluid dynamics) ,PROBLEM solving - Abstract
A novel computational fluid dynamics-population balance model (CFD-PBM) for the simulation of gas mixing in activated sludge (i.e., an opaque non-Newtonian liquid) in a bubble column is developed and described to solve the problem of measuring the hydrodynamic behavior of opaque non-Newtonian liquid-gas two-phase flow. We study the effects of the inlet position and liquid-phase properties (water/activated sludge) on various characteristics, such as liquid flow field, gas hold-up, liquid dynamic viscosity, and volume-averaged bubble diameter. As the inlet position changed, two symmetric vortices gradually became a single main vortex in the flow field in the bubble column. In the simulations, when water was in the liquid phase, the global gas hold-up was higher than when activated sludge was in the liquid phase in the bubble column, and a flow field that was dynamic with time was observed in the bubble column. Additionally, when activated sludge was used as the liquid phase, no periodic velocity changes were found. When the inlet position was varied, the non-Newtonian liquid phase had different peak values and distributions of (dynamic) liquid viscosity in the bubble column, which were related to the gas hold-up. The high gas hold-up zone corresponded to the low dynamic viscosity zone. Finally, when activated sludge was in the liquid phase, the volume-averaged bubble diameter was much larger than when water was in the liquid phase. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
45. Improvement of DS Evidence Theory for Multi-Sensor Conflicting Information.
- Author
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Fang Ye, Jie Chen, and Yibing Li
- Subjects
- *
DATA analysis , *DESCRIPTIVE statistics , *DEMPSTER-Shafer theory , *PROBABILITY theory , *COMPUTER simulation - Abstract
A new DS (Dempster-Shafer) combination method is presented in this paper. As data detected by a single sensor are characterized by not only fuzziness, but also partial reliability, the development of multi-sensor information fusion becomes extremely indispensable. The DS evidence theory is an effective means of information fusion, which can not only deal with the uncertainty and inconsistency of multi-sensor data, but also handle the inevitably ambiguity and instability under noise or possible interference. However, the application of DS evidence theory has some limitations when multi-sensor data are conflicting. To address this issue, the DS evidence theory is modified in this paper. Adopting the idea of cluster analysis, we firstly introduce the Lance distance function and spectral angle cosine function to revise original evidence separately before the combination of evidence. Then, based on the modifications of original evidence, an improved conflict redistribution strategy is ulteriorly raised to fuse multi-sensor information. Finally, the numerical simulation analyses demonstrate that the improvement of the DS evidence theory available in this paper overcomes the limitations of conventional DS evidence theory, and realizes more reliable fusion with multi-sensor conflicting information compared to the existing methods. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
46. A Novel Robust Trilateration Method Applied to Ultra-Wide Bandwidth Location Systems.
- Author
-
Jiahong Li, Xianghu Yue, Jie Chen, and Fang Deng
- Subjects
WIRELESS sensor networks ,BANDWIDTH allocation ,TIME-of-flight spectrometry ,MULTIPATH channels ,CENTROID - Abstract
Due to the non-line-of-sight (NLOS) and multipath fading channel (MPF) of the wireless networks, the non-existence of the intersection point often occurs in the range-based localization methods, e.g., the centroid-based trilateration method. To alleviate the problem, a confidence-based intersection method which expands the range of the circle within a certain confidence interval is proposed. In the method, the confidence interval is estimated based on the Cramér-Rao lower bound of the time of flight (TOF) measurement. Furthermore, an intersection determination method is proposed to select the intersection point with higher confidence level. The simulation and experimental results show the superiority of the proposed method in localization accuracy and robustness to noise compared to the conventional trilateration method, e.g., the centroid-based and least squares based trilateration methods. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
47. High-Performance Anti-Retransmission Deception Jamming Utilizing Range Direction Multiple Input and Multiple Output (MIMO) Synthetic Aperture Radar (SAR).
- Author
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Ruijia Wang, Jie Chen, Xing Wang, and Bing Sun
- Subjects
- *
MIMO systems , *SYNTHETIC aperture radar , *ORTHOGONAL frequency division multiplexing , *SIGNAL processing , *ENERGY bands - Abstract
Retransmission deception jamming seriously degrades the Synthetic Aperture Radar (SAR) detection efficiency and can mislead SAR image interpretation by forming false targets. In order to suppress retransmission deception jamming, this paper proposes a novel multiple input and multiple output (MIMO) SAR structure range direction MIMO SAR, whose multiple channel antennas are vertical to the azimuth. First, based on the multiple channels of range direction MIMO SAR, the orthogonal frequency division multiplexing (OFDM) linear frequency modulation (LFM) signal was adopted as the transmission signal of each channel, which is defined as a sub-band signal. This sub-band signal corresponds to the transmission channel. Then, all of the sub-band signals are modulated with random initial phases and concurrently transmitted. The signal form is more complex and difficult to intercept. Next, the echoes of the sub-band signal are utilized to synthesize a wide band signal after preprocessing. The proposed method will increase the signal to interference ratio and peak amplitude ratio of the signal to resist retransmission deception jamming. Finally, well-focused SAR imagery is obtained using a conventional imaging method where the retransmission deception jamming strength is degraded and defocused. Simulations demonstrated the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
48. A Wide-Swath Spaceborne TOPS SAR Image Formation Algorithm Based on Chirp Scaling and Chirp-Z Transform.
- Author
-
Wei Yang, Jie Chen, Hong Cheng Zeng, Peng Bo Wang, and Wei Liu
- Subjects
- *
SYNTHETIC aperture radar , *FREQUENCY spectra , *AZIMUTH , *INTERPOLATION , *SIMULATION methods & models - Abstract
Based on the terrain observation by progressive scans (TOPS) mode, an efficient full-aperture image formation algorithm for focusing wide-swath spaceborne TOPS data is proposed. First, to overcome the Doppler frequency spectrum aliasing caused by azimuth antenna steering, the range-independent derotation operation is adopted, and the signal properties after derotation are derived in detail. Then, the azimuth deramp operation is performed to resolve image folding in azimuth. The traditional dermap function will introduce a time shift, resulting in appearance of ghost targets and azimuth resolution reduction at the scene edge, especially in the wide-swath coverage case. To avoid this, a novel solution is provided using a modified range-dependent deramp function combined with the chirp-z transform. Moreover, range scaling and azimuth scaling are performed to provide the same azimuth and range sampling interval for all sub-swaths, instead of the interpolation operation for the sub-swath image mosaic. Simulation results are provided to validate the proposed algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
49. A Line Graph-Based Continuous Range Query Method for Moving Objects in Networks.
- Author
-
Hengcai Zhang, Feng Lu, and Jie Chen
- Subjects
QUERY (Information retrieval system) ,COMPUTER networks ,SIMULATED annealing - Abstract
The rapid growth of location-based services has motivated the development of continuous range queries in networks. Existing query algorithms usually adopt an expansion tree to reuse the previous query results to get better efficiency. However, the high maintenance costs of the traditional expansion tree lead to a sharp efficiency decrease. In this paper, we propose a line graph-based continuous range (LGCR) query algorithm for moving objects in networks, which is characterized by a novel graph-based expansion tree (GET) structure used to monitor queries in an incremental manner. In particular, GET is developed based on the line graph model of networks and simultaneously supports offline pre-computation to better adapt our proposed algorithm to different sizes of networks. To improve performance, we create a series of related data structures, such as bridgeable edges and distance edges. Correspondingly, we develop several algorithms, including initialization, insertion of objects, filter and refinement and location update, to incrementally re-evaluate continuous range queries. Finally, we implement the GET and related algorithms in the native graph database Neo4J. We conduct experiments using real-world networks and simulated moving objects and compare the proposed LGCR with the existing classical algorithm to verify its effectiveness and demonstrate its greater efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
50. Detoxification of Deoxynivalenol via Glycosylation Represents Novel Insights on Antagonistic Activities of Trichoderma when Confronted with Fusarium graminearum.
- Author
-
Ye Tian, Yanglan Tan, Na Liu, Zheng Yan, Yucai Liao, Jie Chen, de Saeger, Sarah, Hua Yang, Qiaoyan Zhang, and Aibo Wu
- Subjects
DETOXIFICATION (Substance abuse treatment) ,DEOXYNIVALENOL ,GLYCOSYLATION ,ANTAGONISTIC fungi ,TRICHODERMA ,FUSARIUM ,MYCOTOXINS ,PHYSIOLOGICAL control systems - Abstract
Deoxynivalenol (DON) is a mycotoxin mainly produced by the Fusarium graminearum complex, which are important phytopathogens that can infect crops and lead to a serious disease called Fusarium head blight (FHB). As the most common B type trichothecene mycotoxin, DON has toxic effects on animals and humans, which poses a risk to food security. Thus, efforts have been devoted to control DON contamination in different ways. Management of DON production by Trichoderma strains as a biological control-based strategy has drawn great attention recently. In our study, eight selected Trichoderma strains were evaluated for their antagonistic activities on F. graminearum by dual culture on potato dextrose agar (PDA) medium. As potential antagonists, Trichoderma strains showed prominent inhibitory effects on mycelial growth and mycotoxin production of F. graminearum. In addition, the modified mycotoxin deoxynivalenol-3-glucoside (D3G), which was once regarded as a detoxification product of DON in plant defense, was detected when Trichoderma were confronted with F. graminearum. The occurrence of D3G in F. graminearum and Trichoderma interaction was reported for the first time, and these findings provide evidence that Trichoderma strains possess a self-protection mechanism as plants to detoxify DON into D3G when competing with F. graminearum. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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