55 results on '"Yizhen Wu"'
Search Results
2. Global Urban Land Expansion Tends To Be Slope Climbing: A Remotely Sensed Nighttime Light Approach
- Author
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Kaifang Shi, Yuanzheng Cui, Shirao Liu, and Yizhen Wu
- Subjects
Earth and Planetary Sciences (miscellaneous) ,General Environmental Science - Published
- 2023
3. Mapping and evaluating global urban entities (2000–2020): A novel perspective to delineate urban entities based on consistent nighttime light data
- Author
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Kaifang Shi, Yizhen Wu, Shirao Liu, Zuoqi Chen, Chang Huang, and Yuanzheng Cui
- Subjects
General Earth and Planetary Sciences - Abstract
The differences in the definition of urban areas lead to our contrasting or inconsistent understanding of global urban development and their corresponding socioeconomic and environmental impacts. The existing urban areas were widely identified by the boundaries of built-environment or social-connections, rather than urban entities that are essentially the spatial extents of human activity agglomerations. Thus, this study has attempted to map and evaluate global urban entities (2000–2020) from a perspective of an updated urban concept of urban entities based on the consistent remotely sensed nighttime light data. First, a K-means algorithm was developed to cluster urban and non-urban pixels automatically in consideration of global region division. Then, a post-processing was conducted to enhance the temporal and logical consistency of urban entities during the study period. Rationality assessment indicates that urban entities derived from remotely sensed nighttime light data more effectively reflect the spatial agglomeration extents of human activities than those of physical urban areas. Global urban entities increased from 157,733 km2 in 2000 to 470,632 km2 in 2020 accompanied by a differentiated urban expansion at global, continental, and national levels. Our study provides long-time series and fine-resolution datasets (500 m) and new research avenues for spatiotemporal analysis of global urban entity expansion with the improvement of the understanding of urbanization and the emergence of effective urban mapping theories and approaches.
- Published
- 2023
4. Response to Reviewers
- Author
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Yizhen Wu
- Published
- 2023
5. Developing Improved Time-Series DMSP-OLS-Like Data (1992–2019) in China by Integrating DMSP-OLS and SNPP-VIIRS
- Author
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Yizhen Wu, Kaifang Shi, Zuoqi Chen, Shirao Liu, and Zhijian Chang
- Subjects
General Earth and Planetary Sciences ,Electrical and Electronic Engineering - Published
- 2022
6. Identifying and Quantifying Urban Polycentric Development in China From DMSP-OLS Data and Urban Land Data Sets
- Author
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Yizhen Wu, Xuguang Tang, Kaifang Shi, and Jingwei Shen
- Subjects
Geography ,business.industry ,Dmsp ols ,Environmental resource management ,Electrical and Electronic Engineering ,Urban land ,Geotechnical Engineering and Engineering Geology ,business ,China - Published
- 2022
7. Population, GDP, and Carbon Emissions as Revealed by SNPP-VIIRS Nighttime Light Data in China With Different Scales
- Author
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Kaifang Shi, Yizhen Wu, Deren Li, and Xi Li
- Subjects
Electrical and Electronic Engineering ,Geotechnical Engineering and Engineering Geology - Published
- 2022
8. Satellite remote sensing data reveal increased slope climbing of urban land expansion worldwide
- Author
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Kaifang Shi, Guifen Liu, Liang Zhou, Yuanzheng Cui, Shirao Liu, and Yizhen Wu
- Subjects
Urban Studies ,Ecology ,Management, Monitoring, Policy and Law ,Nature and Landscape Conservation - Published
- 2023
9. Supplementary material to 'Measurement report: Production and loss of atmospheric formaldehyde at a suburban site of Shanghai in summertime'
- Author
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Yizhen Wu, Juntao Huo, Gan Yang, Yuwei Wang, Lihong Wang, Shijian Wu, Lei Yao, Qingyan Fu, and Lin Wang
- Published
- 2022
10. Oral leukoplakia in adolescents: Attention to differential diagnosis of inherited genetic syndromes with emphasis on dyskeratosis congenita and Fanconi anemia
- Author
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Shiyi Chen, Chenbin Xu, Yizhen Wu, Wei Liu, and Xi Yang
- Published
- 2023
11. Composition analysis and identification of Chinese glass artifacts
- Author
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Yuhuan Wang, Yunhe Guo, Yizhen Wu, and Jun Zhao
- Abstract
Ancient glass is susceptible to weathering by the burial environment, so it is important to promote the study of weathering and erosion of artifacts so as to make targeted conservation measures. In this paper, the chemical composition of ancient glass artifacts, based on logistic regression to obtain statistical patterns of chemical composition of different types of glass artifacts, and the use of hierarchical clustering method to identify unknown types of glass artifacts. Finding the chemical composition patterns of different categories of glass artifacts is an important reference for studying their raw material sources and facilitating comparative studies of artifacts.
- Published
- 2023
12. Carbon dioxide (CO2) emissions from the service industry, traffic, and secondary industry as revealed by the remotely sensed nighttime light data
- Author
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Linyi Li, Yizhen Wu, Kaifang Shi, Jingwei Shen, and Shirao Liu
- Subjects
business.industry ,Environmental resource management ,Computer Science Applications ,Energy conservation ,chemistry.chemical_compound ,chemistry ,Secondary sector of the economy ,Carbon dioxide ,General Earth and Planetary Sciences ,Environmental science ,Resource management ,business ,Tertiary sector of the economy ,Software - Abstract
Exploring carbon dioxide (CO2) emissions from human activities is essential for urban energy conservation and resource management. Remotely sensed nighttime lights from the Suomi NPP-VIIRS provide spatial consistency in and a low-cost way of revealing CO2 emissions. Although many researches have documented the feasibility of the Suomi NPP-VIIRS data for assessing CO2 emissions, few have systematically revealed the ability of nighttime lights for evaluating CO2 emissions from different industries, such as service industry CO2 emissions (SC), traffic CO2 emissions (TC), and secondary industry CO2 emissions (IC). Here, China was selected as the experimental subject, and we comprehensively explored the relationships between the nighttime lights and SC, TC, and IC, and investigated the factors mediating these relationships. We found that without considering other factors, the nighttime lights only revealed up to 51.2% of TC, followed by 41.7% of IC and 22.7% of SC. When controlling for city characteristic variables, the models showed that there were positive correlations between the Suomi NPP-VIIRS data and SC, IC, and TC, and that nighttime lights have an Inverted-U relationship with SC. The Suomi NPP-VIIRS data are more suitable for revealing SC, TC, and IC in medium-sized and large-sized cities than in small-sized cities and megacities.
- Published
- 2021
13. Does China's City-Size Distribution Present a Flat Distribution Trend? A Socioeconomic and Spatial Size Analysis From DMSP-OLS Nighttime Light Data
- Author
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Yizhen Wu, Shirao Liu, and Kaifang Shi
- Subjects
Suburbanization ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,business.industry ,0211 other engineering and technologies ,Distribution (economics) ,021107 urban & regional planning ,Socioeconomic development ,02 engineering and technology ,01 natural sciences ,Market research ,symbols.namesake ,Econometrics ,symbols ,Pareto distribution ,Computers in Earth Sciences ,Scale (map) ,business ,China ,Socioeconomic status ,0105 earth and related environmental sciences - Abstract
Inconsistent measurements of city-size and a lack of time-series information on urban socioeconomic development have hindered determining whether China's city-size distribution (CD) follows a Pareto distribution according to multiple perspectives. This article has attempted to evaluate China's CD based on the defense meteorological satellite program- operational line-scan system (DMSP-OLS) nighttime light data in terms of socioeconomic size (SS) and spatial size (SC). First, city size was defined from the DMSP-OLS data. Then, whether China's CD followed a Pareto distribution was evaluated from different perspectives. The results show that China's CD from 1995 to 2015 presents a flat distribution trend; the flat distribution trend of the SC is more obvious than that of the SS; “borrowed size” has become an important reason for the flat trend of China's CD; and residential suburbanization, transportation cost reductions, local government policies, and land finances could effectively explain the CD differences in the flat trends between the SS and SC. This article offers an effective means for quantifying and comparing CD in long time series at a large scale (e.g., national scale or regional scale) and provides a scientific decision basis for governments to build a reasonable CD system in China.
- Published
- 2021
14. What urban spatial structure is more conducive to reducing carbon emissions? A conditional effect of population size
- Author
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Kaifang Shi, Guifen Liu, Yuanzheng Cui, and Yizhen Wu
- Subjects
Tourism, Leisure and Hospitality Management ,Geography, Planning and Development ,Forestry ,General Environmental Science - Published
- 2023
15. Suburban greening and suburbanization changing surface urban heat island intensity in China
- Author
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Shirao Liu, Kaifang Shi, Yizhen Wu, and Yuanzheng Cui
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Environmental Engineering ,Geography, Planning and Development ,Building and Construction ,Civil and Structural Engineering - Published
- 2023
16. Identifying and evaluating suburbs in China from 2012 to 2020 based on SNPP–VIIRS nighttime light remotely sensed data
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Shirao Liu, Kaifang Shi, and Yizhen Wu
- Subjects
Global and Planetary Change ,Management, Monitoring, Policy and Law ,Computers in Earth Sciences ,Earth-Surface Processes - Published
- 2022
17. Exploring the effect of urban spatial development pattern on carbon dioxide emissions in China: A socioeconomic density distribution approach based on remotely sensed nighttime light data
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Shirao Liu, Jingwei Shen, Guifen Liu, Yizhen Wu, and Kaifang Shi
- Subjects
Urban Studies ,Ecological Modeling ,Geography, Planning and Development ,General Environmental Science - Published
- 2022
18. Evaluation of clinical efficacy of suture-fixation mucopexy in the treatment of prolapsed hemorrhoid
- Author
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Min Zhai, Yizhen Wu, Ruimin Xu, and Zhijun Zhang
- Subjects
Hemorrhoidectomy ,Pain, Postoperative ,medicine.medical_specialty ,Sutures ,business.industry ,Suture fixation ,medicine.disease ,Hemorrhoids ,Surgery ,Treatment Outcome ,Patient satisfaction ,medicine ,Humans ,Operation time ,Clinical efficacy ,business ,Hospital stay ,Anal function ,Vas score - Abstract
The aim of this study was to evaluate the clinical efficacy of suture-fixation mucopexy in the treatment of prolapsed hemorrhoids.A total of 123 patients with grade II, III, and IV hemorrhoids were admitted to The TCM Hospital of Pu Dong New District between 2018 and 2019. They were randomly divided into the suture-fixation group (SF, N.=60) and the Milligan-Morgan hemorrhoidectomy group (MM, N.=63). Clinical efficacy, postoperative pain, average operation time, hospital stay, complications, and patient satisfaction were prospectively evaluated.No significant differences were identified in clinical efficacy; operation time and hospital stay between the two groups (P0.05). However, VAS Score in the SF group was lower than that in the MM group. And the SF group was also more advantageous in anal function protection (P0.05). In addition, the results of the follow-up survey revealed no significant difference in postoperative recurrence rate and patient satisfaction (P0.05).Compared with Milligan-Morgan hemorrhoidectomy, suture-fixation mucopexy is as effective in the treatment of prolapsed hemorrhoid, but it has more advantages in reducing postoperative pain and protecting the anal function.
- Published
- 2021
19. Speaker-Invariant Adversarial Domain Adaptation for Emotion Recognition
- Author
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Mohammad Soleymani, Yizhen Wu, Yufeng Yin, and Baiyu Huang
- Subjects
Multimodal learning ,Domain adaptation ,Discriminator ,Artificial neural network ,Computer science ,Speech recognition ,Multimodal data ,0202 electrical engineering, electronic engineering, information engineering ,020206 networking & telecommunications ,020201 artificial intelligence & image processing ,02 engineering and technology ,Emotion recognition ,Invariant (mathematics) - Abstract
Automatic emotion recognition methods are sensitive to the variations across different datasets and their performance drops when evaluated across corpora. We can apply domain adaptation techniques e.g., Domain-Adversarial Neural Network (DANN) to mitigate this problem. Though the DANN can detect and remove the bias between corpora, the bias between speakers still remains which results in reduced performance. In this paper, we propose Speaker-Invariant Domain-Adversarial Neural Network (SIDANN) to reduce both the domain bias and the speaker bias. Specifically, based on the DANN, we add a speaker discriminator to unlearn information representing speakers' individual characteristics with a gradient reversal layer (GRL). Our experiments with multimodal data (speech, vision, and text) and the cross-domain evaluation indicate that the proposed SIDANN outperforms (+5.6% and +2.8% on average for detecting arousal and valence) the DANN model, suggesting that the SIDANN has a better domain adaptation ability than the DANN. Besides, the modality contribution analysis shows that the acoustic features are the most informative for arousal detection while the lexical features perform the best for valence detection.
- Published
- 2020
20. Covalent immobilization of the phytic acid-magnesium layer on titanium improves the osteogenic and antibacterial properties
- Author
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Hao Zhang, Yizhen Wu, Chunbo Tang, Yajing Liu, and Jin Wu
- Subjects
Biocompatibility ,Phytic Acid ,Surface Properties ,chemistry.chemical_element ,02 engineering and technology ,01 natural sciences ,Osseointegration ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Osteogenesis ,0103 physical sciences ,Humans ,Magnesium ,Physical and Theoretical Chemistry ,Magnesium ion ,Cell Proliferation ,Titanium ,Phytic acid ,010304 chemical physics ,Cell Differentiation ,Surfaces and Interfaces ,General Medicine ,021001 nanoscience & nanotechnology ,Anti-Bacterial Agents ,chemistry ,Chemical engineering ,Surface modification ,0210 nano-technology ,Biotechnology ,Protein adsorption - Abstract
In order to improve early osseointegration and long-term survival rate of implants, a multifunctional titanium surface that promotes osteogenesis and antibacterial properties is expected. Incorporation of bioactive trace elements such as magnesium ions was proved a promising method to improve osseointegration of titanium. Phytic acid has strong chelating ability with multivalent cations, which has been used in surface modification. Moreover, phytic acid was proved antibacterial potential. Herein, to improve the osteogenic and antibacterial properties, a phytic acid-magnesium (PA-Mg) layer was introduced on titanium using phytic acid as a cross-linker molecule. No obvious changes of the surface characterization were observed by scanning electron microscopy and atomic force microscopy. X-ray photoelectron spectroscopy confirmed that the PA-Mg layer covalently bond to the Ti surface, and the thickness of the PA-Mg layer was about 150 nm. Besides, improved hydrophilic and more protein adsorption were observed on Ti-PA-Mg. Notably, a relatively controlled magnesium release was also observed on Ti-PA-Mg. Human bone mesenchymal stem cells showed better adhesion, proliferation, and osteogenic differentiation on Ti-PA-Mg samples, indicating improved biocompatibility and osteoinductivity. Moreover, Ti-PA-Mg had better antibacterial properties against porphyromonas gingivalis than Ti. Overall, the PA-Mg layer on Ti surface improved the osteogenic and antibacterial properties, which may have promise for use in dental implantation.
- Published
- 2020
21. Ball milling and sintering of neutron absorber Mo-based Tb 2 O 3 -Dy 2 O 3 composite and its characterization
- Author
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Yizhen Wu, Qiang Shen, Ning Li, Dong Lv, Guang Ran, Qijie Feng, Wei Zhou, Meng Wang, and Junqiang Lu
- Subjects
Materials science ,020209 energy ,General Chemical Engineering ,Neutron poison ,Oxide ,chemistry.chemical_element ,Sintering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,chemistry.chemical_compound ,Neutron capture ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,Dysprosium ,Composite material ,0210 nano-technology ,Ball mill ,Solid solution - Abstract
The key to gray control rods controlling and adjusting nuclear reactivity to safely operate a nuclear reactor was in their internal neutron absorbers. New types of Mo-based Tb2O3-Dy2O3 composites used as neutron absorbers were designed and then synthesized by ball milling, cold isostatic pressing and sintering. The microstructure of ball-milled powders and sintered bulks were analyzed. Ball milling induced terbium oxide and dysprosium oxide to be first fined, nano-crystallized, amorphized and finally dissolved into Mo crystal to form Mo (Tb, Dy, O) supersaturated nanocrystalline solid solution, which was driven by mechanical work, not by negative heat of mixing after thermodynamic analysis of a ternary Mo-Tb-Dy systems and the dynamic discussion of ball milling. Sintering caused Tb, Dy and O atoms precipitated from Mo crystal and then formed Tb2O3 and Dy2O3 precipitates that uniformly distributed in Mo matrix. The microhardness, compression strength, coefficient of thermal expansion of sintered bulks were measured, and the corresponding mechanism was also discussed.
- Published
- 2018
22. Phase evolution and microstructure characteristics of Mo-based Tb 2 O 3 -Dy 2 O 3 composites synthesized by ball milling and sintering
- Author
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Dong Lv, Qiang Shen, Guang Ran, Peihua Yang, Wei Zhou, Yizhen Wu, Ning Li, and Chao Ye
- Subjects
010302 applied physics ,Materials science ,General Chemical Engineering ,Sintering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Nanocrystalline material ,Amorphous solid ,Lattice constant ,Mechanics of Materials ,Powder metallurgy ,0103 physical sciences ,Composite material ,0210 nano-technology ,Ball mill ,Solid solution - Abstract
Mo-based Tb 2 O 3 -Dy 2 O 3 composites used as neutron absorbers in nuclear power reactor were synthesized by powder metallurgy. The comparative studies of Mo-based Tb 2 O 3 and Mo-based Dy 2 O 3 composites were carried out to deeply understand the phase evolution and microstructure characteristics of Mo-based Tb 2 O 3 -Dy 2 O 3 composites. Ball milling induced terbium oxide and dysprosium oxide in the powder mixtures to be first fined, nano-crystallized, amorphized and finally dissolved into Mo matrix to form the supersaturated nanocrystalline solid solution that was driven by mechanical work, not by negative heat of mixing. Mo lattice parameter increased with increasing ball-milling time, opposite for Mo grain size. A phase transformation of Dy 2 O 3 crystal from cubic to monoclinic and then to amorphous was observed during ball milling. The microhardness of sintered bulks was first increased and then decreased with increasing sintering time. The maximum value was obtained at the bulks sintered for 8 h. The microhardness and bulk density were increased with increasing sintering temperature before 1600 °C. The mechanism of ball milling and sintering was also discussed.
- Published
- 2018
23. Remotely sensed nighttime lights reveal China's urbanization process restricted by haze pollution
- Author
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Zhijian Chang, Shirao Liu, Kaifang Shi, and Yizhen Wu
- Subjects
Sustainable development ,Visible Infrared Imaging Radiometer Suite ,Environmental Engineering ,Haze ,Geography, Planning and Development ,Building and Construction ,Unit (housing) ,Econometric model ,Climatology ,Urbanization ,Environmental science ,Haze pollution ,China ,Civil and Structural Engineering - Abstract
Under the background of China's active formulation and implementation of haze control policies, clarifying the relationship between the urbanization process (UP) and haze pollution (HP) is an important prerequisite for urban sustainable development. Previous studies have demonstrated the effect of the urbanization process on haze pollution (EUH) from different perspectives, but less attention has been given to the effect of haze pollution on the urbanization process (EHU). Thus, taking 247 prefecture-level cities in China as experimental subjects, this study has attempted to analyze whether HP has an effect on China's UP based on the National Polar-Orbiting Partnership's Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) remotely sensed nighttime light data and econometric models. The results show that for every unit of HP increase, UP slows down by approximately 0.275 units, indicating that HP has restricted UP in China to a certain extent. In addition, in the eastern region of China, HP has also significantly restricted UP. However, in the central and western regions of China, EHU is not significant. Human capital (HC) has been proven to be an important transmission factor for EHU in large cities, medium-sized cities, and eastern developed areas. Based on the above analysis, the study proposed that haze control policies should be implemented according to the UP's characteristics in different regions, and the government should reasonably guide the flow of HC in different regions and promote coordinated development among regions.
- Published
- 2021
24. Quantifying and evaluating the effect of urban expansion on the fine particulate matter (PM2.5) emissions from fossil fuel combustion in China
- Author
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Yizhen Wu, Linyi Li, and Kaifang Shi
- Subjects
0106 biological sciences ,Ecology ,Fine particulate ,General Decision Sciences ,Fossil fuel combustion ,Urban spatial expansion ,010501 environmental sciences ,Urban land ,Atmospheric sciences ,PM2.5 emissions ,Urban socioeconomic expansion ,010603 evolutionary biology ,01 natural sciences ,Urban expansion ,Multiple data ,Variance decomposition of forecast errors ,Haze pollution ,Environmental science ,China ,Nighttime light data ,QH540-549.5 ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
There is no consensus on the effect of China’s rapid urban expansion on the fine particulate matter (PM2.5) emissions from fossil fuel combustion (PC). Previous studies usually focused on the environmental effect of urban expansion from a single mode (e.g., spatial expansion). However, studies that simultaneously considered and compared the effect from spatial and socioeconomic modes are still lacking. Thus, we combined multiple data sources (e.g., nighttime light data, urban land datasets, and PC) and econometric methods to evaluate the effect of urban expansion on PC within different regions from spatial and socioeconomic modes. The results show that China’s urban socioeconomic expansion (UE) and urban spatial expansion (US) increased from 68.50% and 11.81 × 10−4, respectively, in 1992 to 72.23% and 66.86 × 10−4, respectively in 2012. The UE is the Granger cause of the increased PC in China. Through variance decomposition analysis, we also found that the UE contributed much more to the PC in China than the US. When comparing the different regions, we recognized that the UE was the key factor in explaining the increase in the PC in the eastern and northeastern regions, and the US could effectively explain the changes in the PC in the central region. The study provides a novel perspective for quantifying the effect of urban intensive and extensive development on haze pollution.
- Published
- 2021
25. The Effects of Urban Forms on the PM2.5 Concentration in China: A Hierarchical Multiscale Analysis
- Author
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Yizhen Wu, Mingyue Jiang, Kaifang Shi, and Zhijian Chang
- Subjects
Pollution ,China ,Index (economics) ,Fine particulate ,Health, Toxicology and Mutagenesis ,media_common.quotation_subject ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,modifiable areal unit problem ,01 natural sciences ,Article ,PM2.5 concentration ,Air Pollution ,Cities ,0105 earth and related environmental sciences ,media_common ,Air Pollutants ,spatial heterogeneity ,Public Health, Environmental and Occupational Health ,021107 urban & regional planning ,multiscale analysis ,Spatial heterogeneity ,Modifiable areal unit problem ,urban forms ,Environmental science ,Particulate Matter ,Physical geography ,Scale (map) ,Environmental Monitoring ,Panel data - Abstract
For a better environment and sustainable development of China, it is indispensable to unravel how urban forms (UF) affect the fine particulate matter (PM2.5) concentration. However, research in this area have not been updated consider multiscale and spatial heterogeneities, thus providing insufficient or incomplete results and analyses. In this study, UF at different scales were extracted and calculated from remote sensing land-use/cover data, and panel data models were then applied to analyze the connections between UF and PM2.5 concentration at the city and provincial scales. Our comparison and evaluation results showed that the PM2.5 concentration could be affected by the UF designations, with the largest patch index (LPI) and landscape shape index (LSI) the most influential at the provincial and city scales, respectively. The number of patches (NP) has a strong negative influence (−0.033) on the PM2.5 concentration at the provincial scale, but it was not statistically significant at the city scale. No significant impact of urban compactness on the PM2.5 concentration was found at the city scale. In terms of the eastern and central provinces, LPI imposed a weighty positive influence on PM2.5 concentration, but it did not exert a significant effect in the western provinces. In the western cities, if the urban layout were either irregular or scattered, exposure to high PM2.5 pollution levels would increase. This study reveals distinct ties of the different UF and PM2.5 concentration at the various scales and helps to determine the reasonable UF in different locations, aimed at reducing the PM2.5 concentration.
- Published
- 2021
26. A low‐cost, automated parasite diagnostic system via a portable, robotic microscope and deep learning
- Author
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Yizhen Wu, Qianming Xu, Kaiqin Chu, Zachary J. Smith, Mingzhai Sun, Rui Zheng, and Yaning Li
- Subjects
Microscope ,Computer science ,Drug Resistance ,General Physics and Astronomy ,Lateral resolution ,Parasitemia ,Diagnostic system ,Residual ,01 natural sciences ,Convolutional neural network ,General Biochemistry, Genetics and Molecular Biology ,Pattern Recognition, Automated ,Specimen Handling ,law.invention ,Machine Learning ,010309 optics ,Feces ,Deep Learning ,Dogs ,law ,0103 physical sciences ,Image Processing, Computer-Assisted ,Parasite Egg Count ,Drug response ,Animals ,General Materials Science ,Computer vision ,Anthelmintics ,Microscopy ,Sheep ,business.industry ,Goats ,Deep learning ,010401 analytical chemistry ,General Engineering ,Haplorhini ,Robotics ,General Chemistry ,0104 chemical sciences ,Eimeria ,Neural Networks, Computer ,Artificial intelligence ,business - Abstract
Manual hand counting of parasites in fecal samples requires costly components and substantial expertise, limiting its use in resource-constrained settings and encouraging overuse of prophylactic medication. To address this issue, a cost-effective, automated parasite diagnostic system that does not require special sample preparation or a trained user was developed. It is composed of an inexpensive (~US$350), portable, robotic microscope that can scan over the size of an entire McMaster chamber (100 mm2 ) and capture high-resolution (~1 μm lateral resolution) bright field images without need for user intervention. Fecal samples prepared using the McMaster flotation method were imaged, with the imaging region comprising the entire McMaster chamber. These images are then automatically segmented and analyzed using a trained convolution neural network (CNN) to robustly separate eggs from background debris. Simple postprocessing of the CNN output yields both egg species and egg counts. The system was validated by comparing accuracy with hand-counts by a trained operator, with excellent performance. As a further demonstration of utility, the system was used to conveniently quantify drug response over time in a single animal, showing residual disease due to Anthelmintic resistance after 2 weeks.
- Published
- 2019
27. An automated parasite infection diagnostic system via open-source microscopy and deep learning (Conference Presentation)
- Author
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Qianming Xu, Zachary J. Smith, Kaiqin Chu, Yizhen Wu, Rui Zheng, Yaning Li, and Mingzhai Sun
- Subjects
business.industry ,Deep learning ,High resolution ,Pattern recognition ,Diagnostic accuracy ,Biology ,Diagnostic system ,biology.organism_classification ,Eimeria ,Open source ,Microscopy ,Parasite hosting ,Artificial intelligence ,business - Abstract
We report the development of a cost-effective, automated parasite diagnostic system that does not require special sample preparation or a trained user. It is composed of a cost-effective, portable microscope that can automatically auto-focus and scan over the size of an entire McMaster chamber (100 mm2) and capture high resolution (~1 µm) bright field images without need for user intervention. Fecal samples prepared using the McMaster flotation method were imaged, with the imaging region comprising the entire McMaster chamber. A convolutional neural network (CNN) automatically segments and analyzes the images to robustly separate eggs from background debris. The performance of the CNN is high despite the challenging, unbalanced nature of the images, where >95% of images contain no eggs and thus the potential for false-positives is high. Simple post-processing of the CNN output yields both egg species and egg counts. The system was validated by comparing hand counts with automated counts of samples containing eggs from ascarid, strongyle, and Trichuris nematodes, along with Eimeria oocysts. The system shows excellent performance, even on challenging Eimeria parasites whose small size is similar to fecal debris. The R2 values between hand and automated counts are >0.95 for both Eimeria and nematode parasites. Further, the diagnostic accuracy of our system for recommending antibiotic treatment is 100% for nematode parasites and 96% for Eimeria. As a further demonstration of utility, the system was used to conveniently quantify drug response over time, showing residual disease due to antibiotic resistance after 2 weeks.
- Published
- 2019
28. MMP-1 promotes osteogenic differentiation of human bone marrow mesenchymal stem cells via the JNK and ERK pathway
- Author
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Yi Tang, Xiao-zhen Zhang, Chunbo Tang, Yajing Liu, Zhuangzhuang Chu, and Yizhen Wu
- Subjects
0301 basic medicine ,MAPK/ERK pathway ,MAP Kinase Signaling System ,Matrix metalloproteinase ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,stomatognathic system ,Osteogenesis ,Extracellular ,Humans ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Cell Proliferation ,Gene knockdown ,Kinase ,Chemistry ,Regeneration (biology) ,Mesenchymal stem cell ,JNK Mitogen-Activated Protein Kinases ,Cell Differentiation ,Mesenchymal Stem Cells ,Cell Biology ,Cell biology ,RUNX2 ,030104 developmental biology ,030220 oncology & carcinogenesis ,Matrix Metalloproteinase 1 - Abstract
Enhancing the functions of mesenchymal stem cells (MSCs) is considered a potential approach for promoting tissue regeneration. In this study, we investigated the effects of Matrix Metalloproteinase-1 (MMP-1) on bone marrow mesenchymal stem cells (BMSCs) and its mechanism. Our results showed that knockdown of MMP-1 impeded scratch closure, attenuated proliferation, inhibited ALP activity, ALP denser staining and mineralization in vitro, and decreased expression of RUNX2, OSX, OPN and OCN in BMSCs, while 20 ng/mL recombinant human MMP-1 protein (rhMMP-1) significantly accelerated scratch closure, enhanced proliferation, ALP activity, ALP denser staining and mineralization in vitro, and increased expression of RUNX2, OSX, OPN and OCN. In addition, knockdown of MMP-1 inhibited the expression of phosphorylated c-Jun N-terminal kinase (p-JNK) and phosphorylated extracellular regulated protein kinases (p-ERK), while 20 ng/mL rhMMP-1 increased the expression of p-JNK and p-ERK in BMSCs. Furthermore, inhibition of c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases (ERK) by their inhibitor SP600125 and PD98059 dramatically blocked MMP-1-enhanced ALP activity and mineralization in BMSCs. Our results revealed that MMP-1 could accelerate the osteogenic differentiation potentials of BMSCs via the JNK and ERK pathway, providing the mechanism underlying MSC biology and identifying a potential target for improving bone tissue regeneration.
- Published
- 2020
29. Sentiment community detection: exploring sentiments and relationships in social networks
- Author
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Jiexun Li, Dong Wang, Kaiquan Xu, and Yizhen Wu
- Subjects
Service (business) ,Computer science ,business.industry ,Economics, Econometrics and Finance (miscellaneous) ,Sentiment analysis ,02 engineering and technology ,Online advertising ,Human-Computer Interaction ,World Wide Web ,Market segmentation ,020204 information systems ,Business decision mapping ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Product (category theory) ,business ,Social network analysis ,TRACE (psycholinguistics) - Abstract
Social networking sites (SNS), which allow users to express opinions on products/services, have become an important channel and platform for enterprises to acquire and trace users' sentiments in order to design appropriate business strategies and online marketing campaigns. However, with the large number of users and complex user relationships on SNS, effectively capturing these sentiments for business decision support is still a big challenge. In this study we introduce the concept of "Sentiment Community," a group of users who are closely connected and highly consistent in their sentiments about one product/service. Discovering such sentiment communities would be very valuable to enterprises for customer segmentation and target marketing. Taking into account both connections and sentiments, we propose two methods to discover sentiment communities by adopting the optimization models of semi-definite programming (SDP). Our experimental evaluations demonstrated great performances for the proposed methods. This study opens the doors to effectively explore users' sentiments on SNS for business decision making.
- Published
- 2016
30. Fe/Ni Metal–Organic Frameworks and Their Binder-Free Thin Films for Efficient Oxygen Evolution with Low Overpotential
- Author
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Rui Cao, Yizhen Wu, Xiao Feng, Junwen Zhou, Lu Wang, Lantian Ren, Mingxing Chen, and Bo Wang
- Subjects
Tafel equation ,Materials science ,Inorganic chemistry ,Oxygen evolution ,chemistry.chemical_element ,02 engineering and technology ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,Nickel ,chemistry ,General Materials Science ,Metal-organic framework ,Thin film ,0210 nano-technology ,Faraday efficiency - Abstract
Multivariate metal-organic frameworks with active Fe/Ni building blocks that are spatially arranged in an open structure are synthesized and explored for oxygen evolution reaction. The heterogeneity and porosity of this system prove to show synergy effect and give low onset overpotential at 170 mV. These MOFs are further fabricated into thin films over nickel foam by controlled electrochemical deposition to improve the surface conductivity and the overall stability. The Fe/Ni metal-organic framework film exhibits outstanding electrocatalytic activity with low overpotential of 270 mV at 10 mA cm(-2), small Tafel slope, high Faradaic efficiency, high turnover frequency, and great stability.
- Published
- 2016
31. Preparation of five 3-MCPD fatty acid esters, and the effects of their chemical structures on acute oral toxicity in Swiss mice
- Author
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Xiangjun Sun, Jie Liu, Haiming Shi, Haiqiu Huang, Yizhen Wu, Boyan Gao, Thomas T.Y. Wang, Ping-Ping Wu, Liangli Lucy Yu, and Man Liu
- Subjects
0301 basic medicine ,chemistry.chemical_classification ,Creatinine ,Degree of unsaturation ,030109 nutrition & dietetics ,Nutrition and Dietetics ,Fatty acid ,04 agricultural and veterinary sciences ,040401 food science ,Acute toxicity ,03 medical and health sciences ,chemistry.chemical_compound ,0404 agricultural biotechnology ,chemistry ,Biochemistry ,3-MCPD ,Toxicity ,Oral toxicity ,Agronomy and Crop Science ,Blood urea nitrogen ,Food Science ,Biotechnology - Abstract
3-monochloro-1, 2-propanediol fatty acid esters (3-MCPDEs) comprise a group of food toxicants formed during food processing. 3-MCPDEs have received increasing attention concerning their potential negative effects on human health. However, reports on the toxicity of 3-MCPD esters are still limited. To determine the effects of fatty acid substitutions on the toxicity of their esters, 1-stearic, 1-oleic, 1-linoleic, 1-linoleic-2-palmitic and 1-palmitic-2-linoleic acid esters of 3-MCPD were synthesized and evaluated with respect to their acute oral toxicities in Swiss mice.; Results: 3-MCPDEs were obtained through the reaction of 3-MCPD and fatty acid chlorides, and their purities and structures were characterized by ultraperformance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS), infrared, 1 H and 13 C spectroscopic analyses. Medial lethal doses of 1-stearic, 1-oleic, 1-linoleic, 1-linoleic-2-palmitic and 1-palmitic-2-linoleic acid esters were 2973.8, 2081.4, 2016.3, 5000 and > 5000 mg kg-1 body weight. For the first time, 3-MCPDEs were observed for their toxic effects in the thymus and lung. In addition, major histopathological changes, as well as blood urea nitrogen and creatinine, were examined for mice fed the five 3-MCPDEs.; Conclusion: The results from the present study suggest that the degree of unsaturation, chain length, number of substitution and relative substitution locations of fatty acids might alter the toxicity of 3-MCPDEs. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.
- Published
- 2016
32. [Toxoplasma gondii ROP38 promotes the maturation of dendritic cells mediated by TLR4]
- Author
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Heng, Zhang, Shanghua, Wu, Zhiqiang, Shi, Shan, Wang, Wei, Lu, Yizhen, Wu, Pei, Sun, and Qianming, Xu
- Subjects
Male ,Toll-Like Receptor 4 ,Mice ,Protein Domains ,Protozoan Proteins ,Animals ,Humans ,Dendritic Cells ,Protein Kinases ,Toxoplasma ,Toxoplasmosis - Abstract
Objective To investigate the effect of rhoptry protein 38 (ROP38) from Toxoplasma gondii (T. gondii) on the maturation of dendritic cells (DCs) by Toll-like receptor 4 (TLR4) induction in vitro. Methods The total RNA from T. gondii RH strain was extracted by guanidine thiocyanate method, and then cDNA was synthesized with reverse transcription reaction. After ROP38 gene was amplified by PCR, the recombinant pGEX-4T-ROP38 was constructed and expressed under IPTG induction. The recombinant ROP38 protein was detected by SDS-PAGE and Western blot analysis. The secondary structure and antigenicity of the ROP38 were predicted through DNAStar8.0 and ProtScale. In vitro, DCs were isolated and cultured for 6 days, then reacted with ROP38 antigen for 2 hours. The CD11c was detected by flow cytometry, and the data were analyzed with ANOVA by SPSS 23.0 software. Results The amplified gene was about 516 bp as expected. The sequence analysis showed that its homology was 99% compared with the reported sequence (XM_002366710.2) from GenBank. It was found that the relative molecular mass (M
- Published
- 2018
33. BlockONet: Blockchain-based Trusted Cloud Radio over Optical Fiber Network for 5G Fronthaul
- Author
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Young Lee, Haowei Zheng, Jie Zhang, Yuefeng Ji, Hui Yang, and Yizhen Wu
- Subjects
Network architecture ,Optical fiber ,business.industry ,Computer science ,Data_MISCELLANEOUS ,020208 electrical & electronic engineering ,Testbed ,Optical communication ,Cloud computing ,02 engineering and technology ,01 natural sciences ,law.invention ,010309 optics ,Fronthaul ,Identification (information) ,Radio over fiber ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,business ,5G ,Computer network - Abstract
We first present a blockchain-based trusted cloud radio over optical fiber network architecture (BlockONet) with anonymous access identification for future 5G fronthaul. The feasibility and efficiency of the architecture are experimentally verified on our testbed.
- Published
- 2018
34. An Iron-based Film for Highly Efficient Electrocatalytic Oxygen Evolution from Neutral Aqueous Solution
- Author
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Yongzhen Han, Mingxing Chen, Rui Cao, Wei Zhang, Junliang Sun, Yizhen Wu, and Xiaohuan Lin
- Subjects
Electrolysis ,Materials science ,Aqueous solution ,Inorganic chemistry ,Oxygen evolution ,Nanotechnology ,Electrocatalyst ,law.invention ,X-ray photoelectron spectroscopy ,law ,Transmission electron microscopy ,Water splitting ,General Materials Science ,Cyclic voltammetry - Abstract
An ultrathin Fe-based film was prepared by electrodeposition from an Fe(II) solution through a fast and simple cyclic voltammetry method. The extremely low Fe loading of 12.3 nmol cm(-2) on indium tin oxide electrodes is crucial for high atom efficiency and transparence of the resulted film. This Fe-based film was shown to be a very efficient electrocatalyst for oxygen evolution from neutral aqueous solution with remarkable activity and stability. In a 34 h controlled potential electrolysis at 1.45 V (vs NHE) and pH 7.0, impressive turnover number of 5.2 × 10(4) and turnover frequency of 1528 h(-1) were obtained. To the best of our knowledge, these values represent one of the highest among electrodeposited catalyst films for water oxidation under comparable conditions. The morphology and the composition of the catalyst film was determined by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray, and X-ray photoelectron spectroscopy, which all confirmed the deposition of Fe-based materials with Fe(III) oxidation state on the electrode. This study is significant because of the use of iron, the fast and simple cyclic voltammetry electrodeposition, the extremely low catalyst loading and thus the transparency of the catalyst film, the remarkable activity and stability, and the oxygen evolution in neutral aqueous media.
- Published
- 2015
35. Teasaponin improves leptin sensitivity in the prefrontal cortex of obese mice
- Author
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Yizhen Wu, Sen Wang, Xu-Feng Huang, Alexander M Szabo, Shijia Yu, Qing Wang, and Yinghua Yu
- Subjects
Leptin ,Male ,STAT3 Transcription Factor ,medicine.medical_specialty ,Palmitic Acid ,Mice, Obese ,Prefrontal Cortex ,Biology ,Diet, High-Fat ,Weight Gain ,Neurotrophic factors ,Hyperinsulinism ,Cortex (anatomy) ,Internal medicine ,medicine ,Animals ,Insulin ,Obesity ,Prefrontal cortex ,Cells, Cultured ,Neurons ,Brain-derived neurotrophic factor ,Tea ,Brain-Derived Neurotrophic Factor ,Neurodegeneration ,Neurogenesis ,Saponins ,medicine.disease ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Endocrinology ,Saturated fatty acid ,Food Science ,Biotechnology - Abstract
Scope Obesity impairs cognition, and the leptin-induced increase of brain-derived neurotrophic factor (BDNF) and neurogenesis. Tea consumption improves cognition and increases brain activation in the prefrontal cortex. Methods and results This study examined whether teasaponin, an active ingredient in tea, could improve memory and central leptin effects on neurogenesis in the prefrontal cortex of obese mice, and in vitro in cultured prefrontal cortical neurons. Teasaponin (10 mg/kg, intraperitoneal) for 21 days improved downstream leptin signaling (JAK2 and STAT3), and leptin's effect on BDNF, in the prefrontal cortex of high-fat diet (HFD) fed mice. Prefrontal cortical neurons were cultured with teasaponin and palmitic acid (the most abundant dietary saturated fatty acid) to examine their effects on neurogenesis and BDNF expression in response to leptin. Palmitic acid decreased leptin's effect on neurite outgrowth, postsynaptic density protein 95, and BDNF expression in cultured cortical neurons, which was reversed by teasaponin. Conclusion Teasaponin improved the leptin sensitivity of prefrontal cortical neurons in obese mice or when treated by palmitic acid. This in turn increased BDNF expression and neurite growth. Therefore, teasaponin supplementation may be used to prevent obesity-associated neurodegeneration and improve cognitive function.
- Published
- 2015
36. Electrocatalytic Water Oxidation by a Water-Soluble Nickel Porphyrin Complex at Neutral pH with Low Overpotential
- Author
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Yizhen Wu, Rui Cao, Yongzhen Han, and Wenzhen Lai
- Subjects
Electrolysis ,Aqueous solution ,Inorganic chemistry ,chemistry.chemical_element ,Homogeneous catalysis ,Overpotential ,Electrochemistry ,Electrocatalyst ,law.invention ,Catalysis ,Inorganic Chemistry ,Nickel ,chemistry ,law ,Physical and Theoretical Chemistry - Abstract
The water-soluble cationic nickel(II) complex of meso-tetrakis(4-N-methylpyridyl)porphyrin (1) can electrocatalyze water oxidation to O2 in neutral aqueous solution (pH 7.0) with the onset of the catalytic wave appearing at ∼1.0 V (vs NHE). The homogeneous catalysis with 1 was verified. Catalyst 1 exhibited water oxidation activity in a pH range 2.0-8.0 and had a strict linear dependence of catalytic current on its concentration. After 10 h of constant potential electrolysis at 1.32 V (vs NHE), a negligible difference of the solution was observed by UV-vis. In addition, inspection of the working electrode by electrochemistry, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX) showed no sign of deposition of NiOx films. These results strongly argued that 1 is a real molecular electrocatalyst for water oxidation. The turnover frequency (TOF) for this process was 0.67 s(-1) at 20 °C. On the basis of results from the kinetic isotope effect (KIE) and inhibition experiments, electrochemical studies in various buffer solutions with different anions and pHs, and DFT calculations, a catalytic cycle of 1 for water oxidation via a formally Ni(IV) species was proposed.
- Published
- 2015
37. Palmitic acid induces central leptin resistance and impairs hepatic glucose and lipid metabolism in male mice
- Author
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Hongqin Wang, Yinghua Yu, Alexander M Szabo, Danielle Camer, Xu-Feng Huang, Licai Cheng, and Yizhen Wu
- Subjects
Leptin ,Male ,medicine.medical_specialty ,Tyrosine 3-Monooxygenase ,Endocrinology, Diabetes and Metabolism ,Saturated fat ,Clinical Biochemistry ,Hypothalamus ,Palmitic Acid ,Carbohydrate metabolism ,Biology ,Biochemistry ,Energy homeostasis ,Mice ,Internal medicine ,medicine ,Animals ,Molecular Biology ,Inflammation ,Nutrition and Dietetics ,Leptin receptor ,digestive, oral, and skin physiology ,Lipid metabolism ,Lipid Metabolism ,Mice, Inbred C57BL ,Glucose ,Endocrinology ,Liver ,Lipogenesis ,Saturated fatty acid ,hormones, hormone substitutes, and hormone antagonists ,Signal Transduction - Abstract
The consumption of diets rich in saturated fat largely contributes to the development of obesity in modern societies. A diet high in saturated fats can induce inflammation and impair leptin signaling in the hypothalamus. However, the role of saturated fatty acids on hypothalamic leptin signaling, and hepatic glucose and lipid metabolism remains largely undiscovered. In this study, we investigated the effects of intracerebroventricular (icv) administration of a saturated fatty acid, palmitic acid (PA, C16:0), on central leptin sensitivity, hypothalamic leptin signaling, inflammatory molecules and hepatic energy metabolism in C57BL/6J male mice. We found that the icv administration of PA led to central leptin resistance, evidenced by the inhibition of central leptin's suppression of food intake. Central leptin resistance was concomitant with impaired hypothalamic leptin signaling (JAK2-STAT3, PKB/Akt-FOXO1) and a pro-inflammatory response (TNF-α, IL1-β, IL-6 and pIκBa) in the mediobasal hypothalamus and paraventricular hypothalamic nuclei. Furthermore, the pre-administration of icv PA blunted the effect of leptin-induced decreases in mRNA expression related to gluconeogenesis (G6Pase and PEPCK), glucose transportation (GLUT2) and lipogenesis (FAS and SCD1) in the liver of mice. Therefore, elevated central PA concentrations can induce pro-inflammatory responses and leptin resistance, which are associated with disorders of energy homeostasis in the liver as a result of diet-induced obesity.
- Published
- 2015
38. Orientin improves depression-like behavior and BDNF in chronic stressed mice
- Author
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Yizhen Wu, Jing Ren, Xu-Feng Huang, Shu-ting Wang, Nuo Lan, Yinghua Yu, and Yi Liu
- Subjects
Male ,Serotonin ,medicine.medical_specialty ,Hippocampus ,medicine.disease_cause ,Synaptic Transmission ,Mice ,Norepinephrine ,chemistry.chemical_compound ,Glucosides ,Neurotrophic factors ,Internal medicine ,medicine ,Animals ,Chronic stress ,Flavonoids ,Orientin ,Brain-derived neurotrophic factor ,Neuronal Plasticity ,Behavior, Animal ,Depression ,business.industry ,Brain-Derived Neurotrophic Factor ,Antidepressive Agents ,Disease Models, Animal ,Oxidative Stress ,Endocrinology ,chemistry ,Antidepressant ,business ,Stress, Psychological ,Oxidative stress ,Food Science ,Biotechnology - Abstract
cope Oxidative stress is involved in chronic stress-induced depression and the disruption of neurotransmission and neuroplasticity. Recently, orientin, a phenolic compound abundant in some fruits, millet, and herbs, has been shown to have antioxidant properties. This study investigated the potential antidepressant effects of orientin against chronic stress and its underlying mechanisms. Methods and results The chronic unpredictable mild stress (CUMS) model was used to investigate the effects of orientin on behavior and biochemical alterations in mice. After 2 weeks of the CUMS protocol, the mice were treated with orientin (20 mg/kg and 40 mg/kg, oral gavage) for 3 weeks. Administration of orientin significantly alleviated the CUMS-induced depression-like behavior, including sucrose preference reduction, locomotor activity decline, and hypomotility. Orientin treatment attenuated the oxidative stress markers and increased the concentrations of serotonin and norepinephrine in the hippocampus and prefrontal cortex of CUMS mice. Orientin treatment also increased the brain-derived neurotrophic factor and synapse-associated proteins (synaptophysin and postsynaptic density protein 95) of CUMS mice. Conclusion Orientin exerts antidepressant-like effects on CUMS mice, specifically by improving central oxidative stress, neurotransmission, and neuroplasticity. Therefore, supplementation with orientin-enriched food or fruit could be beneficial as a preventive strategy for chronic stress-induced depression.
- Published
- 2015
39. Preparation of Cobalt-Based Electrodes by Physical Vapor Deposition on Various Nonconductive Substrates for Electrocatalytic Water Oxidation
- Author
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Le Wang, Yizhen Wu, Wei Zhang, Zhaoxia Jin, Rui Cao, and Mingxing Chen
- Subjects
Materials science ,010405 organic chemistry ,General Chemical Engineering ,Inorganic chemistry ,chemistry.chemical_element ,Overpotential ,010402 general chemistry ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,General Energy ,chemistry ,Physical vapor deposition ,Electrode ,Environmental Chemistry ,General Materials Science ,Cyclic voltammetry ,Thin film ,Cobalt ,Polyimide - Abstract
Artificial photosynthesis requires efficient anodic electrode materials for water oxidation. Cobalt metal thin films are prepared through facile physical vapor deposition (PVD) on various nonconductive substrates, including regular and quartz glass, mica sheet, polyimide, and polyethylene terephthalate (PET). Subsequent surface electrochemical modification by cyclic voltammetry (CV) renders these films active for electrocatalytic water oxidation, reaching a current density of 10 mA cm-2 at a low overpotential of 330 mV in 1.0 m KOH solution. These electrodes are robust with unchanged activity throughout prolonged chronopotentiometry measurements. This work is thus significant to show that the combination of PVD and CV is very valuable and convenient to fabricate active electrodes on various nonconductive substrates, particularly with flexible polyimide and PET substrates. This efficient, safe and convenient method can potentially be expanded to many other electrochemical applications.
- Published
- 2017
40. Blockchain-based trusted authentication in cloud radio over fiber network for 5G
- Author
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Yuefeng Ji, Haowei Zheng, Hui Yang, Young Lee, Yizhen Wu, and Jie Zhang
- Subjects
Radio access network ,Authentication ,Blockchain ,business.industry ,Computer science ,020208 electrical & electronic engineering ,Testbed ,Core network ,020206 networking & telecommunications ,Cloud computing ,02 engineering and technology ,Radio over fiber ,0202 electrical engineering, electronic engineering, information engineering ,business ,5G ,Computer network - Abstract
Cloud radio access network (C-RAN) interconnects thousands of terminal devices to support the services of Internet of Things (IoT) in 5G area. However, centralized access authentication of each terminal has been performed in mobile core network which causes an extremely high operating and capital expenditure of network. Traditional C-RAN cannot provide an authentic mechanism to guarantee the security of services and creditability of device and resource accessing with low network cost. We first propose a blockchain-based trusted authentication (BTA) architecture for 5G with blockchain-based anonymous access (BAA) scheme in cloud radio over fiber network. The feasibility and efficiency are verified on enhanced SDN testbed to enable blockchain as a service.
- Published
- 2017
41. Ginsenoside Rb1 improves leptin sensitivity in the prefrontal cortex in obese mice
- Author
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Yizhen Wu, Yinghua Yu, Xu-Feng Huang, and Christopher Bell
- Subjects
0301 basic medicine ,Leptin ,Male ,medicine.medical_specialty ,Neurite ,Ginsenosides ,Saturated fat ,Neuronal Outgrowth ,Synaptogenesis ,Palmitic Acid ,Prefrontal Cortex ,Diet, High-Fat ,03 medical and health sciences ,Random Allocation ,0302 clinical medicine ,Neurotrophic factors ,In vivo ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Pharmacology (medical) ,Obesity ,Cognitive decline ,Prefrontal cortex ,Cells, Cultured ,Pharmacology ,Neurons ,business.industry ,Brain-Derived Neurotrophic Factor ,digestive, oral, and skin physiology ,Original Articles ,eye diseases ,Mice, Inbred C57BL ,Psychiatry and Mental health ,030104 developmental biology ,Endocrinology ,Synapses ,Anti-Obesity Agents ,business ,030217 neurology & neurosurgery ,hormones, hormone substitutes, and hormone antagonists ,Central Nervous System Agents - Abstract
Aim Obesity impairs leptin-induced regulation of brain-derived neurotrophic factor (BDNF) expression and synaptogenesis, which has been considered to be associated with the incidence of neuronal degenerative diseases, cognitive decline, and depression. Ginsenoside Rb1 (Rb1), a major bioactive component of ginseng, is known to have an antiobesity effect and improve cognition. This study examined whether Rb1 can improve central leptin effects on BDNF expression and synaptogenesis in the prefrontal cortex during obesity using an in vivo and an in vitro model. Result Ginsenoside Rb1 (Rb1) chronic treatment improved central leptin sensitivity, leptin-JAK2-STAT3 signaling, and leptin-induced regulation of BDNF expression in the prefrontal cortex of high-fat diet-induced obese mice. In cultured prefrontal cortical neurons, palmitic acid, the saturated fat, impaired leptin-induced BDNF expression, reduced the immunoreactivity and mRNA expression of synaptic proteins, and impaired leptin-induced neurite outgrowth and synaptogenesis. Importantly, Rb1 significantly prevented these pernicious effects induced by palmitic acid. Conclusion These results indicate that Rb1 reverses central leptin resistance and improves leptin-BDNF-neurite outgrowth and synaptogenesis in the prefrontal cortical neurons. Thus, Rb1 supplementation may be a beneficial avenue to treat obesity-associated neurodegenerative disorders.
- Published
- 2017
42. Electrocatalysis: A Thin NiFe Hydroxide Film Formed by Stepwise Electrodeposition Strategy with Significantly Improved Catalytic Water Oxidation Efficiency (Adv. Energy Mater. 9/2017)
- Author
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Rui Cao, Wei Zhang, Jing Qi, Mingxing Chen, and Yizhen Wu
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,Oxygen evolution ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Water splitting ,Hydroxide ,General Materials Science ,0210 nano-technology - Published
- 2017
43. In Situ TEM Study of Microstructure Evolution of Zr-Nb-Fe Alloy Irradiated by 800 keV Kr
- Author
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Penghui, Lei, Guang, Ran, Chenwei, Liu, Chao, Ye, Dong, Lv, Jianxin, Lin, Yizhen, Wu, and Jiangkun, Xu
- Subjects
nanoparticle ,ion irradiation ,zirconium alloy ,in situ TEM ,Article ,nanocrystallization - Abstract
The microstructure evolution of Zr-1.1Nb-1.51Fe-0.26Cu-0.72Ni zirconium alloy, irradiated by 800 keV Kr2+ ions at 585 K using the IVEM-Tandem Facility at Argonne National Laboratory, was observed by in situ transmission electron microscopy. A number of β-Nb precipitates with a body-centered cubic (BCC) structure were distributed in the as-received zirconium alloy with micrometer-size grains. Kr2+ ion irradiation induced the growth of β-Nb precipitates, which could be attributed to the segregation of the dissolved niobium atoms in the zirconium lattice and the migration to the existing precipitates. The size of precipitates was increased with increasing Kr2+ ion fluence. During Kr2+ iron irradiation, the zirconium crystals without Nb precipitates tended to transform to the nanocrystals, which was not observed in the zirconium crystals with Nb nanoparticles. The existing Nb nanoparticles were the key factor that constrained the nanocrystallization of zirconium crystals. The thickness of the formed Zr-nanocrystal layer was about 300 nm, which was consistent with the depth of Kr2+ iron irradiation. The mechanism of the precipitate growth and the formation of zirconium nanocrystal was analyzed and discussed.
- Published
- 2017
44. Blockchain Mechanism Based on Enhancing Consensus for Trusted Optical Networks
- Author
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Siqi Kou, Jie Zhang, Haowei Zheng, Hui Yang, Yizhen Wu, and Wei Bai
- Subjects
Blockchain ,Computer science ,business.industry ,Reliability (computer networking) ,Peer to peer computing ,Optical security ,Mechanism based ,Resource management ,Network topology ,business ,Protocol (object-oriented programming) ,Computer network - Abstract
We achieve trusted optical networks by introducing enhancing blockchain consensus protocol which take dynamic leaders to write blocks into blockchain. Simulation results show that improved mechanism can achieve better performance.
- Published
- 2017
45. Improved Process for Pilot-Scale Synthesis of Danshensu ((±)-DSS) and Its Enantiomer Derivatives
- Author
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Lingjian Yang, Qin Fanggang, Pu Jia, Jianli Liu, Qun-Zheng Zhang, Jing Wang, Yizhen Wu, Xuexia An, Liu Pei, Zhe Sun, Xiaokang Gao, Kai Luo, Yajun Zhang, Cuiling Wang, Gao Rong, Xue Meng, Xiaohui Zheng, Wang Xiaoxiao, Yefei Nan, Yajun Bai, Chaoni Xiao, Xunli Zhang, Shixiang Wang, Sha Liao, Yuhong Sun, Xinfeng Zhao, and Fang Jiacheng
- Subjects
chemistry.chemical_compound ,Chromatography ,Chemistry ,Yield (chemistry) ,Organic Chemistry ,Pilot scale ,Physical and Theoretical Chemistry ,Enantiomer ,Catalysis ,Nuclear chemistry ,Lactic acid - Abstract
A pilot-scale process has been developed for green and scalable synthesis of (±)-β-(3,4-dihydroxyphenyl) lactic acid ((±)-DSS) and their two important derivatives, namely, (±)-IDHP [(±)-isopropyl 2-hydroxy-3-(3,4-dihydroxyphenyl)propanoate] and (±)-DBZ [(±)-bornyl 2-hydroxy-3-(3,4-dihydroxyphenyl)propanoate]. Subsequent hydrogenation has been carried out by employing Raney Ni as catalyst. The improved process results in higher yields of 47.5% for (±)-DBZ and 49.2% for (±)-IDHP compared to the initial process with a yield of 12% for (±)-DBZ and 18% for (±)-IDHP in our original medicinal chemistry route. Furthermore, kilograms of optical DBZ [(−)-S-DBZ and (+)-R-DBZ, >99% ee] and IDHP [(−)-S-IDHP and (+)-R-IDHP, >99% ee] have been produced by chiral high-performance liquid chromatography in good yield (>84%).
- Published
- 2013
46. Reduction of histamine H1 receptor binding induced by high-fat diet can be prevented by DHA and dietary fiber in specific brain areas of male rats
- Author
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Craig S Patch, Yinghua Yu, Yizhen Wu, Xu-Feng Huang, Alexander M Szabo, and Zhixiang Wu
- Subjects
Dietary Fiber ,Male ,medicine.medical_specialty ,food.ingredient ,Docosahexaenoic Acids ,Diet and obesity ,Histamine H1 receptor ,Biology ,Diet, High-Fat ,chemistry.chemical_compound ,food ,Piriform cortex ,Internal medicine ,medicine ,Animals ,Receptors, Histamine H1 ,Rats, Wistar ,Resistant starch ,Radionuclide Imaging ,Receptor ,General Neuroscience ,Brain ,Rats ,Ventral tegmental area ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Docosahexaenoic acid ,Histamine - Abstract
High-fat (HF) diet and obesity are risk factors for a number of mental health problems including depression, cognitive dysfunction, dementia, and neurodegenerative diseases. Histamine H1 receptors (H1Rs) are involved in many of these conditions. This study examined H1R receptor binding density in the brain of male rats fed a high-saturated fat (HF) diet, as well as the effect of docosahexaenoic acid (DHA), galacto-oligosaccharide (GOS) and resistant starch (RS) supplementation of HF diet. Alterations of H1R expression in the post-mortem rat brain were detected by [(3)H]-pyrilamine binding autoradiography. We found that HF diet significantly decreased H1R binding densities in the substantia nigra (SN), caudate putamen (CPu), hypothalamic arcuate nucleus (Arc), ventral tegmental area (VTA), piriform cortex (Pir) and primary motor cortex (M1), compared with low-fat fed rats, and the suppression of receptor binding density ranged from 31% to 48%. Interestingly, supplementing the HF diet with 0.5% n-3 polyunsaturated docosahexaenoic acid (DHA) prevented reduction of H1R binding densities in the SN and CPu. Addition of galacto-oligosaccharide (GOS) and resistant starch (RS) to the diet blunted HF induced reduction of H1R ligand binding in the SN and Pir, respectively. In conclusion this study showed that HF diet can alter H1R binding densities in various brain regions, and many of these changes can be prevented by adding DHA, GOS or RS to the diet.
- Published
- 2013
47. DHA prevents altered 5-HT1A, 5-HT2A, CB1 and GABAA receptor binding densities in the brain of male rats fed a high-saturated-fat diet
- Author
-
Yizhen Wu, Duo Li, Alexander M Szabo, Craig S Patch, Xu-Feng Huang, Zhixiang Wu, and Yinghua Yu
- Subjects
Male ,medicine.medical_specialty ,Cannabinoid receptor ,Docosahexaenoic Acids ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Saturated fat ,Clinical Biochemistry ,Hippocampus ,Biology ,Biochemistry ,Receptor, Cannabinoid, CB1 ,Internal medicine ,medicine ,Animals ,Receptor, Serotonin, 5-HT2A ,Rats, Wistar ,Receptor ,Molecular Biology ,5-HT receptor ,Nutrition and Dietetics ,GABAA receptor ,Brain ,food and beverages ,Receptors, GABA-A ,Dietary Fats ,Rats ,Endocrinology ,nervous system ,Docosahexaenoic acid ,Receptor, Serotonin, 5-HT1A ,lipids (amino acids, peptides, and proteins) ,Cannabinoid ,Protein Binding - Abstract
Low levels of docosahexaenoic acid (DHA) have been linked to a number of mental illnesses such as memory loss, depression and schizophrenia. While supplementation of DHA is beneficial in improving memory and cognition, the influence of dietary fats on the neurotransmitters and receptors involved in cognitive function is still not known. The aim of this study was to investigate serotonin receptor (5-HT 1A and 5-HT 2A ), cannabinoid receptor (CB1) and gamma-aminobutyric acid type A (GABA A ) receptor binding densities in the brain of male rats fed a high-saturated-fat (HF) diet, as well as the effect of DHA supplementation on HF diet. Alterations of these receptors in the post-mortem rat brain were detected by [ 3 H]-WAY-100635, [ 3 H]-ketanserin, [ 3 H]-CP-55,940 and [ 3 H]-muscimol binding autoradiography, respectively. In the hippocampus, the 5-HT 1A , CB1 and GABA A receptor binding densities significantly increased in response to an HF diet, while in the hypothalamus, 5-HT 1A and CB1 binding densities significantly increased in HF-fed rats. Importantly, DHA supplementation prevented the HF-induced increase of receptors binding density in the hippocampus and hypothalamus. Furthermore, DHA supplementation attenuated 5-HT 2A receptor binding density in the caudate putamen, anterior cingulate cortex and medial mammillary nucleus, which was also increased in HF group. This study showed that an HF diet increased 5-HT 1A , 5-HT 2A , CB1 and GABA A receptor binding densities in the brain regions involved in cognitive function and that dietary DHA can attenuate such alterations. These findings provide insight into the mechanism by which DHA supplementation ameliorates reduced cognitive function associated with an HF diet.
- Published
- 2013
48. Teasaponin Reduces Inflammation and Central Leptin Resistance in Diet-Induced Obese Male Mice
- Author
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Zhixiang Wu, Yizhen Wu, Alexander M Szabo, Xu-Feng Huang, Duo Li, Yinghua Yu, and Hongqin Wang
- Subjects
Leptin ,Male ,medicine.medical_specialty ,Pro-Opiomelanocortin ,medicine.medical_treatment ,Hypothalamus, Middle ,Adipose tissue ,Inflammation ,Diet, High-Fat ,Camellia sinensis ,Proinflammatory cytokine ,Mice ,Random Allocation ,Endocrinology ,Insulin resistance ,Internal medicine ,Appetite Depressants ,medicine ,Animals ,Obesity ,Neurons ,Tea ,Plant Extracts ,business.industry ,Insulin ,Anti-Inflammatory Agents, Non-Steroidal ,NF-kappa B ,medicine.disease ,Mice, Inbred C57BL ,Adipose Tissue ,Liver ,Hypothalamus ,Insulin Resistance ,medicine.symptom ,business ,Diet-induced obese ,Injections, Intraperitoneal ,Signal Transduction - Abstract
Chronic inflammation is involved in the pathogenesis of obesity and type 2 diabetes. Recently teasaponin, an extract from tea, has been shown to have antiinflammatory effects. We examined the effect of teasaponin on obesity, inflammation, glucose metabolism, and central leptin sensitivity in obese mice fed a high-fat (HF) diet for 16 weeks. Intraperitoneal injections of teasaponin (10 mg/kg, daily) for 21 days significantly decreased the food intake and body weight of HF diet-induced obese mice. Teasaponin treatment also reduced the protein levels of proinflammatory cytokines (TNF-α, IL-6, and/or IL-1β) and nuclear factor-κB signaling (phosphorylated inhibitory-κB kinase and phosphorylated inhibitory-κBα) in adipose tissue and the liver. The antiinflammatory effects of teasaponin were associated with improved glycemic status in the treated animals, evidenced by improved glucose tolerance, homeostasis model assessment, and fasting plasma insulin. In the hypothalamus, teasaponin decreased both proinflammatory cytokines and inflammatory signaling in the mediobasal hypothalamus. Teasaponin treatment also enhanced the anorexigenic effect of central leptin administration, restored leptin phosphorylated signal transducer and activator of transcription-3 (p-STAT3) signaling in the arcuate nucleus, and increased hypothalamic expression of the anorexigenic peptide proopiomelanocortin. These results identify a potential novel application for teasaponin as an antiobesity and antiinflammatory agent.
- Published
- 2013
49. Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry for Identification of In Vitro and In Vivo Metabolites of Bornyl Gallate in Rats
- Author
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Xue Meng, Jie Yu, Sha Liao, Yizhen Wu, Wei Lan, Liujiao Bian, Xinfeng Zhao, Shixiang Wang, Xiaohui Zheng, and Pu Jia
- Subjects
lcsh:QD71-142 ,Chromatography ,Antioxidant ,Article Subject ,Molecular mass ,Formic acid ,General Chemical Engineering ,medicine.medical_treatment ,lcsh:Analytical chemistry ,Mass spectrometry ,Computer Science Applications ,Analytical Chemistry ,Borneol ,chemistry.chemical_compound ,Metabolic pathway ,chemistry ,In vivo ,medicine ,Gallic acid ,Instrumentation ,Research Article - Abstract
Bornyl gallate (BG) is a potential drug candidate synthesized by the reaction of two natural products, gallic acid and borneol. Previous studies have strongly suggested that BG is worthy of further investigation due to antioxidant, antiatherosclerosis activities, and obvious activity of stimulating intersegmental vessel growth in zebrafish. This work was designed to elucidate the metabolic profile of BG through analyzing its metabolites in vitro and in vivo by a chromatographic separation coupled with a mass spectrometry. The metabolites of BG were characterized from the rat liver microsome incubation solution, as well as rat urine and plasma after oral administration. Chromatographic separation was performed on an Agilent TC-C18column (250 mm × 4.6 mm, 5 μm) with gradient elution using methanol and water containing 0.2% (V : V) formic acid as the mobile phase. Metabolites identification involved analyzing the retention behaviors, changes of molecular weights and MS/MS fragment patterns of BG and the metabolites. Five compounds were identified as isomers of hydroxylated BG metabolites in vitro. The major metabolites of BG in rat urine and plasma proved to be BG-O-glucuronide and O-methyl BG-O-glucuronide. The proposed method confirmed to be a reliable and sensitive alternative for characterizing metabolic pathways of BG.
- Published
- 2013
50. Preparation of five 3-MCPD fatty acid esters, and the effects of their chemical structures on acute oral toxicity in Swiss mice
- Author
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Man, Liu, Jie, Liu, Yizhen, Wu, Boyan, Gao, Pingping, Wu, Haiming, Shi, Xiangjun, Sun, Haiqiu, Huang, Thomas Ty, Wang, and Liangli Lucy, Yu
- Subjects
Male ,Neurons ,Behavior, Animal ,Molecular Structure ,Food Handling ,Brain ,Food Contamination ,Organ Size ,Thymus Gland ,Diglycerides ,Lethal Dose 50 ,Mice ,Random Allocation ,Structure-Activity Relationship ,Liver ,Hydrocarbons, Chlorinated ,Toxicity Tests, Acute ,Animals ,Monoglycerides ,Female ,Neurotoxicity Syndromes - Abstract
3-monochloro-1, 2-propanediol fatty acid esters (3-MCPDEs) comprise a group of food toxicants formed during food processing. 3-MCPDEs have received increasing attention concerning their potential negative effects on human health. However, reports on the toxicity of 3-MCPD esters are still limited. To determine the effects of fatty acid substitutions on the toxicity of their esters, 1-stearic, 1-oleic, 1-linoleic, 1-linoleic-2-palmitic and 1-palmitic-2-linoleic acid esters of 3-MCPD were synthesized and evaluated with respect to their acute oral toxicities in Swiss mice.3-MCPDEs were obtained through the reaction of 3-MCPD and fatty acid chlorides, and their purities and structures were characterized by ultraperformance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS), infrared,The results from the present study suggest that the degree of unsaturation, chain length, number of substitution and relative substitution locations of fatty acids might alter the toxicity of 3-MCPDEs. © 2016 Society of Chemical Industry.
- Published
- 2015
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