88 results on '"Heng, Xiao"'
Search Results
2. Tempo-spacial variation and source apportionment of atmospheric formaldehyde in the Pearl River Delta, China
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Wei, Cheng-Bo, primary, Yu, Guang-He, additional, Cao, Li-Ming, additional, Han, Heng-Xiao, additional, Xia, Shi-Yong, additional, and Huang, Xiao-Feng, additional
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- 2023
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3. MiR-652-3p promotes malignancy and metastasis of cancer cells via inhibiting TNRC6A in hepatocellular carcinoma
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Wei Chen, Junnan Ru, Tong Wu, Da Man, Jingbang Wu, Lijuan Wu, Yujing Sun, Hanxi Yu, Min Li, Gangwei Zhang, Xingxin Zhu, Rongliang Tong, Heng Xiao, Yanhua Li, and Beng Yang
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Biophysics ,Cell Biology ,Molecular Biology ,Biochemistry - Abstract
Hepatocellular carcinoma (HCC) was one of the most prevalent life-threatening cancers. Metastasis is the leading cause of cancer-related death in HCC. MiRNAs play essential roles in cancer metastasis.Expression of miR-652-3p in HCC was assessed. Function experiments of miR-652-3p and trinucleotide repeat-containing gene 6A protein (TNRC6A) were performed both in vitro and in vivo. mRNA sequencing, PCR, and western blot were performed to verify the target genes and pathway of miR-652-3p. The lung metastasis and xenograft cancer model in nude mice was established to investigate the effects of the miR-652-3p and TRNC6A on tumor metastasis in vivo. The relationship between the expression of the miR-652-3p, TNRC6A and the prognosis of HCC patients was analyzed.Upregulated miR-652-3p was found in the tumor tissues of HCC, especially in metastatic HCC patients. Overexpression of miR-652-3p promoted and knockdown of miR-652-3p suppressed HCC metastasis both in vitro and in vivo. MiR-652-3p promoted HCC metastasis via regulating the EMT pathway. TNRC6A was identified as a direct target of miR-652-3p, and the knockdown of TNRC6A restored repressed EMT and HCC metastasis caused by the inhibition of miR-652-3p. Clinical results revealed that high expression of miR-652-3p and low expression of TNRC6A were positively correlated to shortened overall survival and disease-free survival in HCC patients.MiR-652-3p promotes EMT and HCC metastasis by inhibiting TNRC6A expression in HCC. MiR-652-3p and TNRC6A may serve as potential biomarkers to predict prognosis in HCC patients with metastasis.
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- 2023
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4. Influence of spatial distribution of fine sand layers on the mechanical behavior of coral reef sand
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Xu, Dong-sheng, primary, Zhao, Heng-xiao, additional, Fan, Xiaochun, additional, and Qin, Yue, additional
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- 2023
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5. Spleen in viral Hepatitis-B liver fibrosis patients may have a reduced level of per unit micro-circulation: non-invasive diffusion MRI evidence with a surrogate marker
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Cun-Jing Zheng, Hua Huang, Ben-Heng Xiao, Ting Li, Wei Wang, and Yì Xiáng J. Wáng
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Liver Cirrhosis ,Male ,Medical Laboratory Technology ,Diffusion Magnetic Resonance Imaging ,Humans ,Female ,Hepatitis B ,Biomarkers ,Spleen ,Aged ,Retrospective Studies ,Computer Science Applications - Abstract
Spleen micro-perfusion level can be evaluated by DDVD (diffusion derived vessel density): DDVD (unit: au/pixel) = Sb0/ROIarea0 - Sb2/ROIarea2, where Sb0 and Sb2 refer to the spleen signal when b is 0 or 2 (s/mm
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- 2022
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6. Evaluation of key factors influencing urban ozone pollution in the Pearl River Delta and its atmospheric implications
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Lin, Xiao-Yu, primary, Xia, Shi-Yong, additional, Luo, Yao, additional, Han, Heng-Xiao, additional, and He, Ling-Yan, additional
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- 2023
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7. Usefulness of diffusion derived vessel density computed from a simplified IVIM imaging protocol: An experimental study with rat biliary duct blockage induced liver fibrosis
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Gen-Wen Hu, Yi-Xiang J. Wang, Dan-Ping Zhuang, Ben-Heng Xiao, Cun-Jing Zheng, and Weixiang Zhong
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Liver Cirrhosis ,Male ,Diffusion ,Liver fibrosis ,Biomedical Engineering ,Biophysics ,Rats, Sprague-Dawley ,Motion ,Vessel density ,Fibrosis ,medicine ,Animals ,Radiology, Nuclear Medicine and imaging ,Intravoxel incoherent motion ,Chemistry ,business.industry ,Bile duct ligation ,Reproducibility of Results ,medicine.disease ,Rats ,Diffusion Magnetic Resonance Imaging ,Liver ,Nuclear medicine ,business ,Perfusion ,Diffusion MRI - Abstract
Aim: Liver vessel density can be evaluated by DDVD (diffusion derived vessel density): DDVD(b0b1) = Sb0/ROIarea0-Sb1/ROIarea1, where Sb0 and Sb1 refer to the liver signal when b is 0 or 1 (s/mm 2); ROIarea0 and ROIarea1 refer to the region-of-interest on b= 0 or 1 images. Sb1 and ROIarea1 may be replaced by Sb25 and ROIarea25 or Sb50 and ROIarea50 (i.e., by images of b=25 or 50 s/mm 2). With rat biliary duct ligation (BDL) model, this study assessed the usefulness of liver DDVD computed from a simplified IVIM imaging protocol. Materials and Methods: Male Sprague-Dawley rats were used, and 1, 2, 3, 4 weeks post BDL had rat number of 5, 5, 5,3 respectively. Partial recanalization (n=12) was performed with rats had BDL for 7 days and MRI was done mean 14 days after recanalization. Liver diffusion MR images were acquired using with a 3.0T magnet with a b-value distribution of 0, 30, 50, 75, 100, 150, 300, 700, 1000 s/mm 2. DDVDmean (control rats n=6) was the mean of DDVD(b0b25) and DDVD(b0b50). IVIM fitting started from b = 0 with segmented fitting and a threshold b of 50 s/mm 2 (n=5 for control rats). Three 3-D space was constructed using PF, D slow , and D fast ; PF, D slow , and DDVD mean ; or PF, D fast , and DDVD mean. Results: BDL week 1, 2, 3, 4 rats and partial recanalization rats had mean liver fibrosis METAVIR score of 1.5, 2.4, 3.25, 3.7 and 2.42 respectively. The control rats and BDL rats (n=18) had a liver DDVD mean of 84.0±26.2 and 44.7±14.4 au/pixel (p
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- 2021
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8. Hyper-Parameter Optimization for Improving the Performance of Localization in an Iterative Ensemble Smoother
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Xiaodong Luo, William Cruz, Xin-Lei Zhang, and Heng Xiao
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- 2023
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9. 3D numerical modeling for thermo-mechanical behavior of additively manufactured titanium alloy parts with process-induced defects
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Zhi-Jian Li, Zhi-Heng Xiao, Hai-Liang Zhang, Hong-Liang Dai, Wei-Feng Luo, and Zheng-Wei Huang
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Fluid Flow and Transfer Processes ,Mechanical Engineering ,Condensed Matter Physics - Published
- 2023
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10. Evaluation of key factors influencing urban ozone pollution in the Pearl River Delta and its atmospheric implications
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Xiao-Yu Lin, Shi-Yong Xia, Yao Luo, Heng-Xiao Han, and Ling-Yan He
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Atmospheric Science ,General Environmental Science - Published
- 2023
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11. Influence of spatial distribution of fine sand layers on the mechanical behavior of coral reef sand
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Dong-sheng Xu, Heng-xiao Zhao, Xiaochun Fan, and Yue Qin
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Soil Science ,Geotechnical Engineering and Engineering Geology ,Civil and Structural Engineering - Published
- 2023
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12. Influence of thermal decomposition and regional transport on atmospheric peroxyacetyl nitrate (PAN) observed in a megacity in southern China
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Xia, Shi-Yong, primary, Huang, Xiao-Feng, additional, Han, Heng-Xiao, additional, Li, Xin, additional, and Yu, Guang-He, additional
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- 2022
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13. An explicit and accurate approach toward simulating plastic-to-pseudoelastic transitions of SMAs under multiple loading and unloading cycles
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Lin Zhan, Hui-Feng Xi, Heng Xiao, Si-Yu Wang, and Xiao-Ming Wang
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Yield surface ,Computer science ,Applied Mathematics ,Mechanical Engineering ,Experimental data ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Model validation ,Nonlinear system ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Extensive data ,Hardening (metallurgy) ,Applied mathematics ,General Materials Science ,0210 nano-technology - Abstract
New finite elastoplastic J2-flow equations are proposed for the purpose of explicitly simulating continuous transitions from plastic to pseudo-elastic effects of SMAs under multiple loading-unloading cycles. Novelties of such models are as follows: (i) New hardening effects are incorporated by introducing interplay between the changing of the yield surface radius and the moving of the yield surface center; (ii) extensive experimental data may be accurately simulated for any given number of loading-unloading cycles; (iii) the complicated task for simulating extensive data may be accomplished by independently fitting certain single-variable functions; and (iv) such single-variable functions may be presented in explicit forms for the purpose of automatically, accurately fitting extensive data, thus bypassing uncertainties and undue complexities usually involved in iteratively solving a coupled system of nonlinear constitutive rate equations toward identifying numerous unknown parameters. Numerical examples for model validation are presented and in good agreement with stress-strain data up to 20 loading-unloading cycles given in literature.
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- 2020
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14. Seasonal variation and provenance of organic matter in the surface sediments of the three gorges reservoir: Stable isotope analysis and implications for agricultural management
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Heng Xiao, Changping Mao, Shuai Wang, Zhimin Jia, and Wenbo Rao
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Environmental Engineering ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
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15. Exact large strain analysis for the Poynting effect of freely twisted thin-walled tubes made of highly elastic soft materials
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Meng-Liang Han, Hui-Yu Wang, Si-Yu Wang, and Heng Xiao
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Mechanical Engineering ,Building and Construction ,Civil and Structural Engineering - Published
- 2023
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16. Quantitative Evaluation of Major Factors Influencing Atmospheric Ozone Pollution in a Chinese Megacity
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Xiao-Yu Lin, Xiao-Feng Huang, Shi-Yong Xia, Meng-Xue Tang, Yao Luo, Heng-Xiao Han, Jing Wei, Bo Zhu, and Ling-Yan He
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- 2022
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17. Fractional-Order Heterogeneous Neuron Network With Hr Neuron and Fhn Neuron Based on Coupled Locally-Active Memristors: Super Coexisting Firing Behaviors, Bursting Behaviors and its Application
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Dawei Ding, Heng Xiao, Zongli Yang, Honglin Luo, Yongbing Hu, Yan Liu, and Mouyuan Wang
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
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18. Bioinspired inverse enamel-like columnar composites reproducing the mechanical properties and tribological performance of human enamel
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Lei Lei, Dan Yang, Jing Zheng, Zhixin Wu, Heng Xiao, and Zhongrong Zhou
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General Materials Science - Published
- 2022
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19. Quantitative Evaluation of Major Factors Influencing Atmospheric Ozone Pollution in a Chinese Megacity
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Lin, Xiao-Yu, primary, Huang, Xiao-Feng, additional, Xia, Shi-Yong, additional, Tang, Meng-Xue, additional, Luo, Yao, additional, Han, Heng-Xiao, additional, Wei, Jing, additional, Zhu, Bo, additional, and He, Ling-Yan, additional
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- 2022
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20. Physicochemical characterization, antioxidant and hypoglycemic activities of selenized polysaccharides from Sargassum pallidum
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Xiong Fu, Chao Li, Chun Chen, Heng Xiao, and Qiang Huang
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Antioxidant ,Chemical Phenomena ,Iron ,medicine.medical_treatment ,chemistry.chemical_element ,02 engineering and technology ,Polysaccharide ,Biochemistry ,Antioxidants ,Selenium ,03 medical and health sciences ,Ingredient ,Non-competitive inhibition ,Picrates ,Polysaccharides ,Structural Biology ,medicine ,Hypoglycemic Agents ,Glycoside Hydrolase Inhibitors ,Chelation ,Benzothiazoles ,Food science ,Sargassum pallidum ,Molecular Biology ,Chelating Agents ,030304 developmental biology ,Acarbose ,chemistry.chemical_classification ,0303 health sciences ,biology ,Biphenyl Compounds ,Sargassum ,General Medicine ,021001 nanoscience & nanotechnology ,biology.organism_classification ,Molecular Weight ,Kinetics ,chemistry ,Sulfonic Acids ,0210 nano-technology ,medicine.drug - Abstract
This study was carried out to study the effects of selenylation on physicochemical and biological properties of polysaccharide (SPP) extracted from Sargassum pallidum. The selenized derivative of SPP (Se-SPP) with the selenium content of 2419 μg/g was synthesized by sodium selenite/dilute nitric acid method. Physicochemical characterization indicated that selenylation modification resulted in some changes in chemical composition, monosaccharide composition, molecular weight and surface morphology of polysaccharides. FT-IR spectroscopy showed that a new absorption peak appeared at 675 cm−1 in Se-SPP probably due to the substitution of selenyl groups. Bioactivity assay showed that Se-SPP exhibited higher scavenging radical activities and ferrous ion chelating activities than native SPP. Compared with SPP and acarbose, Se-SPP showed more significantly inhibitory effect on α-glucosidase activity in a noncompetitive inhibition type. The IC50 values of SPP, Se-SPP and acarbose were determined as 1.579, 0.896 and 2.742 mg/mL, respectively. These results suggest that Se-SPP can be used to develop a new selenium-complementary ingredient in functional foods.
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- 2019
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21. Effect of saliva flow rate on the adsorption kinetics and lubrication of salivary pellicle on human tooth enamel surface
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Zhongrong Zhou, Genlei Ma, Qihang Zeng, Heng Xiao, Jing Zheng, Dan Yang, and L. Zheng
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Saliva ,Materials science ,Saliva secretion ,02 engineering and technology ,Adsorption ,stomatognathic system ,0203 mechanical engineering ,Human tooth ,Materials Chemistry ,medicine ,Enamel paint ,Surfaces and Interfaces ,Quartz crystal microbalance ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Volumetric flow rate ,stomatognathic diseases ,020303 mechanical engineering & transports ,medicine.anatomical_structure ,Chemical engineering ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,Lubrication ,0210 nano-technology - Abstract
The adsorption and lubrication of salivary pellicle is closely associated with saliva secretion, while the relationship between saliva flow rate and salivary pellicle lubrication is still unclear. In this study, the adsorption kinetics and lubrication behavior of salivary pellicle on human tooth enamel surface has been investigated in vitro at different salivary flow rates using quartz crystal microbalance with dissipation (QCM-D) and nano-indentation/scratch technique. Human whole saliva was collected from healthy donors. Regardless of flow rates, salivary protein adsorption on the enamel surface experiences initially rapid saturated adsorption to form a stable multi-layer structure of salivary pellicle and then slow oversaturated adsorption of some proteins with weak bonding. With the flow rate increasing, the saturated adsorption process is expedited, but the oversaturated adsorption is decelerated. Hence, the pellicle has decreased roughness, thickness, viscoelasticity, and normal load-bearing capability at high flow rates than at low flow rates. Its anti-wear properties are slightly weakened but its friction-reducing properties are enhanced. In sum, there exists a coupling effect of flow rate and adsorption time on the adsorption of salivary proteins. Saliva lubrication mainly depends on the saturated adsorption of salivary proteins on enamel surface.
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- 2019
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22. Research of the role of microstructure in the wear mechanism of canine and bovine enamel
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Zhongrong Zhou, Jiapin Peng, Qihang Zeng, Heng Xiao, Dan Yang, Jing Zheng, and Lei Lei
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Materials science ,Biomedical Engineering ,02 engineering and technology ,Biomaterials ,03 medical and health sciences ,Dogs ,0302 clinical medicine ,Brittleness ,stomatognathic system ,medicine ,Animals ,Composite material ,Dental Enamel ,Mechanical Phenomena ,Enamel paint ,Delamination ,Fracture mechanics ,030206 dentistry ,Tribology ,021001 nanoscience & nanotechnology ,Tooth enamel ,Microstructure ,Hardness ,Biomechanical Phenomena ,stomatognathic diseases ,medicine.anatomical_structure ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,Cattle ,0210 nano-technology - Abstract
The relationship between the microstructure and tribological behavior of mammalian tooth enamel has not been fully understood. In this paper, the microstructure, mechanical properties, and tribological behavior of canine (carnivore) and bovine (herbivore) enamel are studied using scanning electronic microscopy and nano-indentation/scratch technique, aiming to reveal the contribution of enamel microstructure to its mechanical and tribological properties. Canine enamel has a microstructure of hard keyhole-like rods embedded in soft inter-rod enamel, and its surface exhibits high resistance against both micro-crack initiation and crack-induced delamination during friction and wear process. Bovine enamel with the microstructure consisting of the hydroxyapatite (HAP) nano-fibers in decussation has higher surface hardness and better capabilities of resisting wear and encumbering crack propagation, as compared to canine enamel. In sum, the soft inter-rod enamel in the canine enamel contributes to high load tolerance and then protects enamel surface from brittle damage, while the staggered arrangement of HAP nano-fibers benefits hard bovine enamel in crack propagation resistance and then help resist wear and fatigue. The findings suggest that there exists a self-adaptation in enamel microstructure and tribological performance of mammals with their feeding habits, which will promote and assist the bionic design of high-performance materials.
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- 2019
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23. NUPR1 promotes the proliferation and migration of breast cancer cells by activating TFE3 transcription to induce autophagy
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Mi-Duo Tan, Jing Long, Heng Xiao, and Xiang Chen
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Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ,Autophagy ,TFE3 ,Breast Neoplasms ,Cell Biology ,Biology ,Neoplasm Proteins ,Transcription (biology) ,Cell Line, Tumor ,Cancer research ,Basic Helix-Loop-Helix Transcription Factors ,Humans ,Female ,Breast cancer cells ,Cell Proliferation - Abstract
Background: Breast cancer is a commonplace carcinoma in females. Recurrence and metastasis are the main problems affecting the survival rate of patients. The fundamental reason is the lack of understanding of the mechanism of breast cancer metastasis. This study aims to deliberate on the efficaciousness of Nuclear protein 1 (NUPR1)-mediated autophagy on breast cancer metastasis.Methods: The proliferation, migration and invasion ability of breast cancer cells were appraised by CCK-8, wound healing, and colony formation, as well as transwell assay. The relationship between NUPR1 and Translocation factor E3 (TFE3) was appraised by qPCR, western blot and ChIP. Migration-invasion-related proteins and autophagy-related proteins were appraised by western blot. The effects of NUPR1 on malignancy formation and metastasis were studied in vivo.Results: NUPR1 was upregulated in breast cancer cells and tissues. NUPR1 knockdown restrained the proliferation, migration and invasion of ZR-75-30 cells. Moreover, NUPR1 knockdown restrained malignancy formation and metastasis in vivo. Mechanically, NUPR1 promoted autophagy through activation of TFE3 transcription, thereby regulating the process of breast cancer metastasis.Conclusion: This paper elucidates the molecular mechanism of NUPR1 promoting breast cancer metastasis by activating autophagy through TFE3 signaling pathway, which provided biological basis for intervention of blocking distant metastasis.
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- 2022
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24. Influence of thermal decomposition and regional transport on atmospheric peroxyacetyl nitrate (PAN) observed in a megacity in southern China
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Shi-Yong Xia, Xiao-Feng Huang, Heng-Xiao Han, Xin Li, and Guang-He Yu
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Atmospheric Science - Published
- 2022
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25. Heterogeneous hardening of enamel surface by occlusal loading: Effect of nanofiber orientation
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Jiapin, Peng, Heng, Xiao, Lei, Lei, Dan, Yang, Jing, Zheng, and Zhongrong, Zhou
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Biomaterials ,Durapatite ,Mechanics of Materials ,Nanofibers ,Biomedical Engineering ,Humans ,Dental Enamel ,Tooth - Abstract
Human tooth enamel is composed of enamel rods and surrounding inter-rod enamel. As the fundamental block of enamel, hydroxyapatite (HAP) nanofibers are mostly longitudinally aligned in the rods but inclined in the inter-rod enamel. The surface hardening of enamel by occlusal loading is reportedly a result of hydroxyapatite nanofiber fragmentation and rearrangement and plays an important role in the anti-wear performance of enamel, but little is known about the effect of HAP nanofiber orientation on enamel surface hardening. In this study, the occlusal loading-induced surface hardening behaviors of enamel at different zones (rod and inter-rod) and different orientations (occlusal and axial) were investigated in vitro using impact treatment and a nanoindentation technique, aiming to reveal the effect of nanofiber orientation on enamel surface hardening. It was found that surface hardening by occlusal loading occurs in the rod and inter-rod areas, but the former shows a greater hardening degree than the latter, leading to an increase in the mechanical heterogeneity of enamel surface. Under the same loading condition, the HAP nanofibers in the inter-rod enamel are more likely to tilt into transverse nanofibers than those in the rods. Compared with longitudinal nanofibers, transverse nanofibers fragment into more transverse crystal particles, but the transverse particles impair the compactness of the hardening layer and decrease its hardening degree. In sum, inherent non-uniform nanofiber orientation endows the enamel with the ability to undergo heterogeneous surface hardening upon occlusal loading, which is critical for providing and maintaining its surface mechanical heterogeneity. These findings extend the understanding of the relationship between microstructure and mechanical properties of dental enamel and provide valuable insights into the bionic design of engineering materials.
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- 2022
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26. Safety and efficacy profile of a phytase produced by fermentation and used as a feed additive
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Thorsen, Michael, primary, Nielsen, Line Anker, additional, Zhai, Heng-Xiao, additional, Zhang, Qian, additional, Wulf-Andersen, Linda, additional, and Skov, Lars Kobberøe, additional
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- 2021
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27. Consolidating effect of hydroxyapatite on the ancient ivories from Jinsha ruins site: Surface morphology and mechanical properties study
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Sheng Yang, Bin Wu, Jing Zheng, Heng Xiao, Wei Gong, Zhongrong Zhou, and L. Zheng
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Archeology ,Materials science ,Materials Science (miscellaneous) ,010401 analytical chemistry ,02 engineering and technology ,Conservation ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Chemistry (miscellaneous) ,Composite material ,0210 nano-technology ,Porosity ,General Economics, Econometrics and Finance ,Elastic modulus ,Spectroscopy - Abstract
In this study, the ancient ivories from Jinsha ruins site have been consolidated through impregnation in aqueous hydroxyapatite (HAP) colloid prepared by the hydrothermal method. Microscopic examinations and nano-indentation/scratch tests were conducted to characterize the morphology and mechanical properties of ivory's surface. After the consolidation treatment, a compact HAP nano-particle layer is formed on the original ivory surface, and the loose and porous surface is repaired. The hardness, elastic modulus, and anti-scratch performance of the repaired ivory surface are significantly improved. Also, the consolidated surface acts as a protective layer, which isolates the ivory from the ambient environment and avoids further deterioration. The consolidation has compatible aesthetics, and does not introduce extraneous substances into the ivory. The results have shown nano-HAP is a promising consolidant for ancient ivories.
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- 2019
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28. A low-cost and real-time pose measurement method for straight pipe jacking machine based on dual-screen laser target in tunneling guidance
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Zhe Huang, Xiaoling Shen, Lin Wang, Yeqian Xu, Qingde Yan, Erjing Cheng, and Heng Xiao
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Applied Mathematics ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Instrumentation - Published
- 2022
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29. Optimization of loop-mediated isothermal amplification (LAMP) assay for robust visualization in SARS-CoV-2 and emerging variants diagnosis
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Zhen Luo, Chunhong Ye, Heng Xiao, Jialing Yin, Yicong Liang, Zhihui Ruan, Danju Luo, Daolong Gao, Qiuping Tan, Yongkui Li, Qiwei Zhang, Weiyong Liu, and Jianguo Wu
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Loop-mediated isothermal amplification (LAMP) ,Emerging SARS-CoV-2 variants ,Applied Mathematics ,General Chemical Engineering ,General Chemistry ,POC, point-of-care ,Ct, threshold cycle ,SARS-CoV-2, severe acute respiratory syndrome coronavirus 2 ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis ,Article ,Industrial and Manufacturing Engineering ,NGS, next-generation sequencing ,LAMP, Loop-mediated isothermal amplification ,CRISPR, clustered regularly interspaced short palindromic repeats ,RT-qPCR, real-time reverse transcriptase quantitative polymerase chain reaction ,IVD, in-vitro diagnosis ,VOC, variants of concern ,ComputingMethodologies_COMPUTERGRAPHICS ,COVID-19, coronavirus disease 2019 ,Coronavirus disease 2019 (COVID-19) pandemic - Abstract
Graphical abstract, Loop-mediated isothermal amplification (LAMP) is widely used in detection of pathogenic microorganisms including SARS-CoV-2. However, the performance of LAMP assay needs further exploration in the emerging SARS-CoV-2 variants test. Here, we design serials of primers and select an optimal set for LAMP-based on SARS-CoV-2 N gene for a robust and visual assay in SARS-CoV-2 diagnosis. The limit of detectable template reaches 10 copies of N gene per 25 μL reaction at isothermal 58℃ within 40 min. Importantly, the primers for LAMP assay locate at 12 to 213 nt of N gene, a highly conservative region, which serves as a compatible test in emerging SARS-CoV-2 variants. Comparison to a commercial qPCR assay, this LAMP assay exerts the high viability in diagnosis of 41 clinical samples. Our study optimizes an advantageous LAMP assay for colorimetric detection of SARS-CoV-2 and emerging variants, which is hopeful to be a promising test in COVID-19 surveillance.
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- 2022
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30. Mitochondrial diversity and phylogeographic structure of native cattle breeds from Yunnan, Southwestern China
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Hesong Liu, Benjuan Zeng, Rong Li, Heng Xiao, Shanyuan Chen, and Chunqing Li
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0301 basic medicine ,Genetic diversity ,General Veterinary ,Phylogenetic tree ,Haplotype ,Genetic admixture ,Biology ,Zebu ,Analysis of molecular variance ,Haplogroup ,Gene flow ,03 medical and health sciences ,030104 developmental biology ,Evolutionary biology ,parasitic diseases ,Animal Science and Zoology ,geographic locations - Abstract
Little is so far known about genetic diversity and phylogeographic structure of native cattle breeds from Yunnan in Southwestern China, a frontier zone that connects China with South and Southeast Asia. Herein we analyzed a 910-bp fragment of mitochondrial DNA (mtDNA) D-loop region sequences of 280 individuals from 6 Yunnan native cattle breeds, of which 251 sequences were newly determined. There were 93 variable sites that defined 117 haplotypes among all sequences. Phylogenetic analysis of all haplotypes revealed that Yunnan native cattle had two distinct mtDNA lineages - taurine and zebu. The taurine sequences fell into four haplogroups T1a, T2, T3 and T4, whereas the zebu sequences grouped into two haplogroups I1 and I2. In addition, our results revealed patterns of gradient changes in frequencies of taurine and zebu mtDNA lineages across different geographic regions of Yunnan. Furthermore, three kinds of methods (haplotype network, analysis of molecular variance, and Mantel tests) consistently showed no significant phylogeographic structuring among Yunnan native cattle breeds. This might be attributed to historical strong gene flow and genetic admixture among native cattle breeds in different geographic regions.
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- 2018
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31. Computer Methods in Applied Mechanics and Engineering
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Jiequn Han, Heng Xiao, and Xu-Hui Zhou
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FOS: Computer and information sciences ,Mathematics, Interdisciplinary Applications ,REPRESENTATION ,Computer Science - Machine Learning ,Nonlocal closure model ,FLOW ,Constitutive equation ,Computational Mechanics ,Closure (topology) ,FOS: Physical sciences ,Engineering, Multidisciplinary ,General Physics and Astronomy ,STRESS MODELS ,Mechanics ,Translation (geometry) ,09 Engineering ,Machine Learning (cs.LG) ,Engineering ,SYSTEMS ,Robustness (computer science) ,EQUATION ,Applied mathematics ,01 Mathematical Sciences ,Artificial neural network ,Applied Mathematics ,Mechanical Engineering ,Fluid Dynamics (physics.flu-dyn) ,Scalar (physics) ,Deep learning ,Physics - Fluid Dynamics ,Computational Physics (physics.comp-ph) ,Grid ,Inverse modeling ,Computer Science Applications ,Constitutive modeling ,Flow (mathematics) ,Mechanics of Materials ,Symmetry and invariance ,TURBULENCE ,Physics - Computational Physics ,Mathematics - Abstract
Constitutive models are widely used for modeling complex systems in science and engineering, where first-principle-based, well-resolved simulations are often prohibitively expensive. For example, in fluid dynamics, constitutive models are required to describe nonlocal, unresolved physics such as turbulence and laminar–turbulent transition. However, traditional constitutive models based on partial differential equations (PDEs) often lack robustness and are too rigid to accommodate diverse calibration datasets. We propose a frame-independent, nonlocal constitutive model based on a vector-cloud neural network that can be learned with data. The model predicts the closure variable at a point based on the flow information in its neighborhood. Such nonlocal information is represented by a group of points, each having a feature vector attached to it, and thus the input is referred to as vector cloud. The cloud is mapped to the closure variable through a frame-independent neural network, invariant both to coordinate translation and rotation and to the ordering of points in the cloud. As such, the network can deal with any number of arbitrarily arranged grid points and thus is suitable for unstructured meshes in fluid simulations . The merits of the proposed network are demonstrated for scalar transport PDEs on a family of parameterized periodic hill geometries. The vector-cloud neural network is a promising tool not only as nonlocal constitutive models and but also as general surrogate models for PDEs on irregular domains.
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- 2022
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32. Research Note: The effect of sequential displacement of dietary dextrose with myo-inositol on broiler chicken growth performance, bone characteristics, ileal nutrient digestibility, and total tract nutrient retention
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Cowieson, A.J., primary and Zhai, Heng-Xiao, additional
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- 2021
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33. Effect of HAP crystallite orientation upon corrosion and tribocorrosion behavior of bovine and human dental enamel
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Joseph A. Arsecularatne, Heng Xiao, Jing Zheng, Zhongrong Zhou, and Mark Hoffman
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Materials science ,Enamel paint ,General Chemical Engineering ,Tribocorrosion ,General Chemistry ,Nanoindentation ,Microstructure ,Focused ion beam ,Corrosion ,stomatognathic diseases ,stomatognathic system ,Transmission electron microscopy ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Crystallite ,Composite material - Abstract
Due to the complexity of the oral environment, understanding the relationship between the enamel microstructure and corrosion behavior of mammalian teeth is important for the development and bionic design of novel dental materials with corrosion resistance. In this paper, enamel microstructure and its influence on corrosion and tribocorrosion behavior of bovine and human molars are studied using focused ion beam & scanning electronic microscopy (FIB-SEM), transmission electron microscope (TEM), nanoindentation, and wear testing. It was found that the regions with transversal HAP nanocrystallites have better corrosion resistance than those with longitudinal crystallites. Apart from the chemical composition, the microstructure of enamel also involves in its surface corrosion. HAP nanocrystallite orientation changes the acid permeability into the enamel surface. Transversal nanocrystallites result in zigzagged acid permeation channels to increase the difficulty of acid penetration and then improve the corrosion resistance of enamel surface. The higher the fraction of transversal nanocrystallites on a surface, the better is the corrosion resistance. These findings extend our understanding of the corrosion/wear mechanisms of dental enamel with different microstructures.
- Published
- 2021
- Full Text
- View/download PDF
34. Direct modeling of multi-axial fatigue failure for metals
- Author
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Heng Xiao and Zhao-Ling Wang
- Subjects
Materials science ,business.industry ,Applied Mathematics ,Mechanical Engineering ,Experimental data ,Fatigue testing ,02 engineering and technology ,Structural engineering ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Nonlinear system ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Thermal ,Hardening (metallurgy) ,Applied mathematics ,General Materials Science ,Multi axial ,0210 nano-technology ,business - Abstract
Innovative elastoplastic J 2 − flow models with nonlinear combined hardening are proposed for the purpose of simulating multi-axial thermo-coupled fatigue failure for metals and alloys, in a direct sense without involving any usual damage-like variables and any ad hoc failure criteria. As contrasted with usual models, the yield condition and the loading-unloading conditions need not be imposed as extrinsic coercive conditions but may be automatically incorporated into a free, smooth flow rule in a more realistic sense. Novel results in three respects are available directly from model predictions, namely, (i) complex features of thermo-coupled fatigue failure may be automatically represented by simple asymptotic properties of the hardening functions introduced, (ii) critical failure states may be derived with a criterion in unified form, and, in particular, (iii) direct procedures may be established for determining fatigue lives under either stress cycles or thermal cycles. Simulation results in the simplest cases of the proposed model are in good agreement with experimental data.
- Published
- 2017
- Full Text
- View/download PDF
35. New multi-axial constitutive models for large elastic deformation behaviors of soft solids up to breaking
- Author
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Xie-Fei Ding, Zheng-Nan Yin, Heng Xiao, and Jie Cao
- Subjects
Materials science ,business.industry ,Applied Mathematics ,Mechanical Engineering ,Constraint (computer-aided design) ,02 engineering and technology ,Structural engineering ,Mechanics ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Hyperelastic material ,Soft solids ,Compressibility ,General Materials Science ,Multi axial ,Deformation (engineering) ,0210 nano-technology ,business ,Softening ,Test data - Abstract
A hyperelastic model is proposed to characterize large elastic deformation behaviors of soft solids. Novelties in four respects are incorporated in this model, namely, (i) general compressible deformations may be treated and, accordingly, the usually-assumed incompressibility constraint and associated issues may be bypassed; (ii) applicability for all kinds of material samples may be automatically ensured, in the sense that any given test data for three deformation modes may be exactly fitted, including uniaxial, equi-biaxial and plane-strain extension; (iii) model parameters of direct physical meanings may be provided to characterize both strain-stiffening and softening effects; and (iv) breaking behavior may be simulated. Numerical results for model validation are in good agreement with Treloar’s classic data for rubbers and with extensive data for various kinds of polymer gels.
- Published
- 2017
- Full Text
- View/download PDF
36. Assimilation of disparate data for enhanced reconstruction of turbulent mean flows
- Author
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Guowei He, Shizhao Wang, Heng Xiao, and Xinlei Zhang
- Subjects
Physics::Fluid Dynamics ,Lift (force) ,Lift-to-drag ratio ,Data assimilation ,General Computer Science ,Disparate system ,Flow (mathematics) ,Computer science ,Turbulence ,Drag ,General Engineering ,Kalman filter ,Mechanics - Abstract
Reconstruction of turbulent flow based on data assimilation methods is of significant importance for improving the estimation of flow characteristics by incorporating limited observations. Existing works mainly focus on using only one observation data source, e.g., velocity, wall pressure, lift or drag force, to reconstruct the flow. In practical applications observations are disparate data sources that often vary in dimension and quality. Simultaneously incorporating these disparate data is worth investigation to improve the flow reconstruction. In this work, we investigate the disparate data assimilation with ensemble methods to enhance the reconstruction of turbulent mean flows. Specifically, a regularized ensemble Kalman method is employed to incorporate the observation of velocity and different sources of wall quantities (e.g., wall shear stress, wall pressure distribution, lift and drag force). Three numerical examples are used to demonstrate the capability of the proposed framework for assimilating disparate observation data. The first two cases, i.e., a one-dimensional planar channel flow and a two-dimensional transitional flow over plate, are used to incorporate both the sparse velocity and wall friction. In the third case of the flow over periodic hills, the wall pressure distribution and the lift and drag force are regarded as observation in addition to velocity, to recover the flow fields. The results demonstrate the merits of incorporating various disparate data sources to improve the accuracy of the flow-field estimation. The ensemble-based method can assimilate disparate data non-intrusively and robustly without requiring significant changes to the model simulation codes. The method demonstrated here opens up possibilities for assimilating realistic experimental data, which are often disparate.
- Published
- 2021
- Full Text
- View/download PDF
37. End-to-end differentiable learning of turbulence models from indirect observations
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Heng Xiao and Carlos A. Michelén Ströfer
- Subjects
Environmental Engineering ,Automatic differentiation ,Computer science ,MathematicsofComputing_NUMERICALANALYSIS ,Biomedical Engineering ,Computational Mechanics ,Aerospace Engineering ,Ocean Engineering ,Reynolds stress ,Physics::Fluid Dynamics ,Machine learning ,Applied mathematics ,Differentiable function ,Adjoint solver ,Turbulence modeling ,ComputingMethodologies_COMPUTERGRAPHICS ,Civil and Structural Engineering ,Artificial neural network ,Turbulence ,Reynolds-averaged Navier-Stokes equations ,Mechanical Engineering ,Engineering (General). Civil engineering (General) ,Nonlinear system ,Mechanics of Materials ,TA1-2040 ,Reynolds-averaged Navier–Stokes equations - Abstract
The emerging push of the differentiable programming paradigm in scientific computing is conducive to training deep learning turbulence models using indirect observations. This paper demonstrates the viability of this approach and presents an end-to-end differentiable framework for training deep neural networks to learn eddy viscosity models from indirect observations derived from the velocity and pressure fields. The framework consists of a Reynolds-averaged Navier–Stokes (RANS) solver and a neural-network-represented turbulence model, each accompanied by its derivative computations. For computing the sensitivities of the indirect observations to the Reynolds stress field, we use the continuous adjoint equations for the RANS equations, while the gradient of the neural network is obtained via its built-in automatic differentiation capability. We demonstrate the ability of this approach to learn the true underlying turbulence closure when one exists by training models using synthetic velocity data from linear and nonlinear closures. We also train a linear eddy viscosity model using synthetic velocity measurements from direct numerical simulations of the Navier–Stokes equations for which no true underlying linear closure exists. The trained deep-neural-network turbulence model showed predictive capability on similar flows.
- Published
- 2021
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38. TAZ regulates cell proliferation and sensitivity to vitamin D3 in intrahepatic cholangiocarcinoma
- Author
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Rongliang Tong, Chaofeng Ding, Beng Yang, Shaobing Cheng, Zhen Lv, Chengli Du, Shusen Zheng, Lin Zhou, Haiyang Xie, Heng Xiao, Jian Wu, and Chuanhui Peng
- Subjects
Male ,0301 basic medicine ,Cancer Research ,medicine.medical_specialty ,Time Factors ,Antineoplastic Agents ,Apoptosis ,Kaplan-Meier Estimate ,Biology ,Transfection ,Cholangiocarcinoma ,03 medical and health sciences ,CYP24A1 ,In vivo ,Cell Line, Tumor ,Internal medicine ,medicine ,Vitamin D and neurology ,Animals ,Hepatectomy ,Humans ,Vitamin D3 24-Hydroxylase ,Intrahepatic Cholangiocarcinoma ,Cell Proliferation ,Cholecalciferol ,Gene knockdown ,Effector ,Cell growth ,Intracellular Signaling Peptides and Proteins ,Cell Cycle Checkpoints ,Middle Aged ,Xenograft Model Antitumor Assays ,Mice, Mutant Strains ,Tumor Burden ,Gene Expression Regulation, Neoplastic ,030104 developmental biology ,Endocrinology ,Bile Duct Neoplasms ,Oncology ,Drug Resistance, Neoplasm ,Transcriptional Coactivator with PDZ-Binding Motif Proteins ,Trans-Activators ,Cancer research ,Female ,RNA Interference ,Tumor Suppressor Protein p53 ,Signal Transduction ,Transcription Factors - Abstract
The transcriptional coactivator with PDZ binding motif (TAZ) is reported as one of the nuclear effectors of Hippo-related pathways. TAZ is found overexpressed in many primary tumors and could regulate many biological processes. However, little is known about the role of TAZ in Intrahepatic Cholangiocarcinoma (ICC). In this study, we found that TAZ is expressed more in ICC tissues than in peritumoral tissue, and a robust expression of TAZ is correlated with a lower overall survival rate of ICC patients after hepatectomy. TAZ knockdown results in an increase in cell apoptosis, a promotion of cell-cycle arrest and a decrease in tumor size and weight in vivo through an increased expression of p53. Vitamin D3 can also inhibit cell proliferation by promoting p53 expression in ICC cells. A reduction in TAZ can also enhance the sensitivity of tumor cells to vitamin D by regulating the p53/CYP24A1 pathway. In conclusion, TAZ is associated with the proliferation and drug-resistance of ICC cells, and could be a novel therapeutic target for the treatment of ICC.
- Published
- 2016
- Full Text
- View/download PDF
39. Explicit, comprehensive modeling of multi-axial finite strain pseudo-elastic SMAs up to failure
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Xiao-Ming Wang, Zhao-Ling Wang, Zheng-Nan Yin, and Heng Xiao
- Subjects
Materials science ,business.industry ,Applied Mathematics ,Mechanical Engineering ,Constitutive equation ,02 engineering and technology ,Shape-memory alloy ,Mechanics ,Structural engineering ,Plasticity ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Nonlinear system ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Finite strain theory ,Hardening (metallurgy) ,General Materials Science ,Deformation (engineering) ,0210 nano-technology ,business ,Test data - Abstract
A new elastoplastic J 2 − flow model with nonlinear combined hardening is proposed for the purpose of achieving an explicit, comprehensive simulation of pseudo-elastic SMAs over the whole range of strain up to failure. To this goal, a new, explicit methodology based on any given uniaxial data is introduced to obtain multi-axial expressions for the constitutive quantities incorporated in this model, in such a unified sense that all three successive deformation stages may be simultaneously represented, including a pseudo-elastic stage with perfect strain recovery, a hardening stage with partial strain recovery, and a softening stage up to failure. As such, any given shapes of uniaxial stress–strain curves from both loading and unloading in these three stages may be automatically reproduced from the proposed model, without involving usual complicated numerical procedures in treating nonlinear rate constitutive equations with a number of switching conditions. Numerical examples with test data are supplied to simulate a complete process including all three stages.
- Published
- 2016
- Full Text
- View/download PDF
40. A novel resorufin based fluorescent 'turn-on' probe for the selective detection of hydrazine and application in living cells
- Author
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Jiaqi Wang, Zhiyong He, Tun Tang, Xiang Zhou, Boshi Fu, Shaoru Wang, Heng Xiao, Fan Wu, and Yuqi Chen
- Subjects
Detection limit ,010405 organic chemistry ,Stereochemistry ,Metal ions in aqueous solution ,Hydrazine ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Fluorescence ,High-performance liquid chromatography ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Naked eye ,Selectivity ,Derivative (chemistry) ,Nuclear chemistry - Abstract
In this study, a resorufin derivative RTP-1, which is a novel fluorescent “turn-on” probe for sensitive detection of hydrazine within 30 min, is designed and synthesized. The selective deprotection of the ester group of the probe by hydrazine led to a prominent enhancement of fluorescent intensity, as well as a remarkable color change from colorless to pink, which could be distinguished by naked eye. The fluorescence enhancement showed decent linear relationship with hydrazine concentration ranging from 0 to 50 μmol/L, with a detection limit of 0.84 μmol/L. The specificity of RTP-1 for hydrazine to a number of metal ions, anions and amines is satisfactory. The sensing mechanism of RTP-1 and hydrazine was evaluated by HPLC, ESI mass spectrometry and density functional theory (DFT). Moreover, we have utilized this fluorescent probe for imaging hydrazine in living cells, and the fluorescence was clearly observed when the cells were incubated with hydrazine (100 μmol/L) for 30 min.
- Published
- 2016
- Full Text
- View/download PDF
41. Evaluation of ensemble methods for quantifying uncertainties in steady-state CFD applications with small ensemble sizes
- Author
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Xinlei Zhang, Olivier Coutier-Delgosha, Heng Xiao, and Thomas Gomez
- Subjects
Computational model ,General Computer Science ,Computer science ,Bayesian probability ,Posterior probability ,General Engineering ,FOS: Physical sciences ,Markov chain Monte Carlo ,Computational Physics (physics.comp-ph) ,Ensemble learning ,symbols.namesake ,Data assimilation ,symbols ,Ensemble Kalman filter ,Uncertainty quantification ,Physics - Computational Physics ,Algorithm - Abstract
Bayesian uncertainty quantification (UQ) is of interest to industry and academia as it provides a framework for quantifying and reducing the uncertainty in computational models by incorporating available data. For systems with very high computational costs, for instance, the computational fluid dynamics (CFD) problem, the conventional, exact Bayesian approach such as Markov chain Monte Carlo is intractable. To this end, the ensemble-based Bayesian methods have been used for CFD applications. However, their applicability for UQ has not been fully analyzed and understood thus far. Here, we evaluate the performance of three widely used iterative ensemble-based data assimilation methods, namely ensemble Kalman filter, ensemble randomized maximum likelihood method, and ensemble Kalman filter with multiple data assimilation for UQ problems. We present the derivations of the three ensemble methods from an optimization viewpoint. Further, a scalar case is used to demonstrate the performance of the three different approaches with emphasis on the effects of small ensemble sizes. Finally, we assess the three ensemble methods for quantifying uncertainties in steady-state CFD problems involving turbulent mean flows. Specifically, the Reynolds averaged Navier–Stokes (RANS) equation is considered the forward model, and the uncertainties in the propagated velocity are quantified and reduced by incorporating observation data. The results show that the ensemble methods cannot accurately capture the true posterior distribution, but they can provide a good estimation of the uncertainties even when very limited ensemble sizes are used. Based on the overall performance and efficiency from the comparison, the ensemble randomized maximum likelihood method is identified as the best choice of approximate Bayesian UQ approach among the three ensemble methods evaluated here.
- Published
- 2020
- Full Text
- View/download PDF
42. Enforcing statistical constraints in generative adversarial networks for modeling chaotic dynamical systems
- Author
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Dragos B. Chirila, Jin-Long Wu, Heng Xiao, Adrian Albert, Karthik Kashinath, and Prabhat
- Subjects
FOS: Computer and information sciences ,Mathematical optimization ,Physics and Astronomy (miscellaneous) ,Complex system ,Physical system ,FOS: Physical sciences ,Machine Learning (stat.ML) ,010103 numerical & computational mathematics ,01 natural sciences ,Statistics - Machine Learning ,0101 mathematics ,Numerical Analysis ,Partial differential equation ,Applied Mathematics ,Fluid Dynamics (physics.flu-dyn) ,Physics - Fluid Dynamics ,Computational Physics (physics.comp-ph) ,Covariance ,Supercomputer ,Computer Science Applications ,010101 applied mathematics ,Maxima and minima ,Computational Mathematics ,Closure (computer programming) ,Modeling and Simulation ,Regularization (physics) ,Physics - Computational Physics - Abstract
Simulating complex physical systems often involves solving partial differential equations (PDEs) with some closures due to the presence of multi-scale physics that cannot be fully resolved. Although the advancement of high performance computing has made resolving small-scale physics possible, such simulations are still very expensive. Therefore, reliable and accurate closure models for the unresolved physics remains an important requirement for many computational physics problems, e.g., turbulence simulation. Recently, several researchers have adopted generative adversarial networks (GANs), a novel paradigm of training machine learning models, to generate solutions of PDEs-governed complex systems without having to numerically solve these PDEs. However, GANs are known to be difficult in training and likely to converge to local minima, where the generated samples do not capture the true statistics of the training data. In this work, we present a statistical constrained generative adversarial network by enforcing constraints of covariance from the training data, which results in an improved machine-learning-based emulator to capture the statistics of the training data generated by solving fully resolved PDEs. We show that such a statistical regularization leads to better performance compared to standard GANs, measured by (1) the constrained model's ability to more faithfully emulate certain physical properties of the system and (2) the significantly reduced (by up to 80%) training time to reach the solution. We exemplify this approach on the Rayleigh-Benard convection, a turbulent flow system that is an idealized model of the Earth's atmosphere. With the growth of high-fidelity simulation databases of physical systems, this work suggests great potential for being an alternative to the explicit modeling of closures or parameterizations for unresolved physics, which are known to be a major source of uncertainty in simulating multi-scale physical systems, e.g., turbulence or Earth's climate.
- Published
- 2020
- Full Text
- View/download PDF
43. Safety and efficacy evaluation of a novel dietary muramidase for swine
- Author
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Schliffka, Wolfgang, primary, Zhai, Heng-Xiao, additional, Pérez Calvo, Estefania, additional, van Cauwenberghe, Sabine, additional, Walsh, Maria C., additional, and Lopez-Ulibarri, Rual, additional
- Published
- 2019
- Full Text
- View/download PDF
44. Virion-associated, host-derived DHX9/RNA helicase A enhances the processivity of HIV-1 reverse transcriptase on genomic RNA
- Author
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Brady, Samantha, primary, Singh, Gatikrushna, additional, Bolinger, Cheryl, additional, Song, Zhenwei, additional, Boeras, Ioana, additional, Weng, Kexin, additional, Trent, Bria, additional, Brown, William Clay, additional, Singh, Kamalendra, additional, Boris-Lawrie, Kathleen, additional, and Heng, Xiao, additional
- Published
- 2019
- Full Text
- View/download PDF
45. Synthesis of distal and proximal fleximer base analogues and evaluation in the nucleocapsid protein of HIV-1
- Author
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Ku, Therese, primary, Lopresti, Natalie, additional, Shirley, Matthew, additional, Mori, Mattia, additional, Marchant, Jan, additional, Heng, Xiao, additional, Botta, Maurizio, additional, Summers, Michael F., additional, and Seley-Radtke, Katherine L., additional
- Published
- 2019
- Full Text
- View/download PDF
46. An explicit, direct simulation of multiaxial finite strain inelastic behavior for polymeric solids
- Author
-
Heng Xiao
- Subjects
Materials science ,Mullins effect ,business.industry ,Mechanical Engineering ,Structural engineering ,Mechanics ,Plasticity ,Strain rate ,Elastomer ,Flow (mathematics) ,Mechanics of Materials ,Finite strain theory ,Coupling (piping) ,General Materials Science ,Elasticity (economics) ,business - Abstract
In contrast with the widely known elastoplastic behavior of hard solids with very small elastic deformations, we study elastoplastic behavior of soft solids dominated by very large elastic deformations. Toward this goal, thermo-coupled rate-independent and rate-dependent elastoplastic J 2 -flow models with evolving rubberlike elasticity are established for the first time in a sense of identically meeting the Clausius–Duhem inequality. Novel results are presented for coupling effects in three respects: (i) how finite strain elastic behavior may evolve with development of plastic flow; (ii) how plastic flow may be induced in a process of pure heating; and (iii) how strain rate effects may be characterized to ensure smooth transitions to the rate-independent case. It is demonstrated that complex inelastic deformation features observed in soft solids such as elastomers, including the Mullins effect, the permanent set, the induced anisotropy, the thermal recovery and the rate effect etc., may be derived as direct, natural consequences of the proposed model. In particular, explicit expressions for the constitutive functions incorporated are derivable from the uniaxial data for the purpose of achieving an explicit, exact simulation of the foregoing inelastic features, thus bypassing usual complexities both in choosing suitable forms of constitutive functions and in identifying unknown parameters in an approximate sense.
- Published
- 2015
- Full Text
- View/download PDF
47. Diffusion-based coarse graining in hybrid continuum–discrete solvers: Applications in CFD–DEM
- Author
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Heng Xiao and Rui Sun
- Subjects
Fluid Flow and Transfer Processes ,Particle number ,business.industry ,Computer science ,Mechanical Engineering ,General Physics and Astronomy ,Computational fluid dynamics ,Solver ,Computational science ,Physics::Fluid Dynamics ,Bounded function ,Overhead (computing) ,Polygon mesh ,Granularity ,business ,CFD-DEM - Abstract
In this work, a coarse-graining method previously proposed by the authors in a companion paper based on solving diffusion equations is applied to CFD–DEM simulations, where coarse graining is used to obtain solid volume fraction, particle phase velocity, and fluid–particle interaction forces. By examining the conservation requirements, the variables to solve diffusion equations for in CFD–DEM simulations are identified. The algorithm is then implemented into a CFD–DEM solver based on OpenFOAM and LAMMPS, the former being a general-purpose, three-dimensional CFD solver based on unstructured meshes. Numerical simulations are performed for a fluidized bed by using the CFD–DEM solver with the diffusion-based coarse-graining algorithm. Converged results are obtained on successively refined meshes, even for meshes with cell sizes comparable to or smaller than the particle diameter. This is a critical advantage of the proposed method over many existing coarse-graining methods, and would be particularly valuable when small cells are required in part of the CFD mesh to resolve certain flow features such as boundary layers in wall bounded flows and shear layers in jets and wakes. Moreover, we demonstrate that the overhead computational costs incurred by the proposed coarse-graining procedure are a small portion of the total computational costs in typical CFD–DEM simulations as long as the number of particles per cell is reasonably large, although admittedly the computational overhead of the coarse-graining procedure often exceeds that of the CFD solver. Other advantages of the diffusion-based algorithm include more robust and physically realistic results, flexibility and easy implementation in almost any CFD solvers, and clear physical interpretation of the computational parameter needed in the algorithm. In summary, the diffusion-based method is a theoretically elegant and practically viable option for practical CFD–DEM simulations.
- Published
- 2015
- Full Text
- View/download PDF
48. Genetic diversity of TLR3 and TLR8 genes among five Chinese native cattle breeds from southwest China
- Author
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Shanyuan Chen, Heng Xiao, Yanyan Chen, Yang Yang, Rong Li, and Chunqing Li
- Subjects
0301 basic medicine ,education.field_of_study ,Genetic diversity ,General Veterinary ,Population ,Haplotype ,0402 animal and dairy science ,Zoology ,04 agricultural and veterinary sciences ,Plant disease resistance ,TLR8 ,Biology ,040201 dairy & animal science ,03 medical and health sciences ,030104 developmental biology ,Gene family ,Animal Science and Zoology ,education ,China ,Gene - Abstract
Members of the Toll-like receptor (TLR) gene family have central roles in initiating innate immune responses after the detection of invading pathogens. In this study, we evaluated the genetic diversity of TLR3 and TLR8 genes among five Chinese native cattle breeds - Yunnan humped (DHMS), Wenshan (WSGN), Dianzhong (CXSB), Zhaotong (ZTGN), and Dengchuan (DLEY) cattle in Yunnan, southwest China. Our results showed that both genes had lower genetic diversity and haplotype diversity in DHMS cattle compared to those of other breeds. Additionally, population genetic analyses of TLR8 suggested that WSGN, DLEY, and ZTLD cattle had experienced a historic population contraction. Analyses of both TLR3 and TLR8 indicated significant negative Fay and Wu's H values (-4.19, p = 0.043 and -6.81, p = 0.004) for Yunnan humped cattle, suggesting recent adaptive evolution. In particular, the distribution of non-synonymous mutations differed among the five Chinese native cattle breeds in Yunnan, implying substantial genetic differences. Furthermore, the predicted functional effects of amino acid substitutions showed that the frequency of damage was lower in DHMS compared to the other four breeds. Thus, our findings suggest that the genetic diversity of TLR3 and TLR8 varied among the five cattle breeds studied, providing important genetic insights into disease resistance in these breeds.
- Published
- 2020
- Full Text
- View/download PDF
49. Thermo-coupled elastoplasticity models with asymptotic loss of the material strength
- Author
-
Heng Xiao
- Subjects
Materials science ,Yield (engineering) ,business.industry ,Mechanical Engineering ,Structure (category theory) ,Structural engineering ,Mechanics ,Physics::Classical Physics ,Strength of materials ,Physics::Geophysics ,Stress (mechanics) ,Flow (mathematics) ,Mechanics of Materials ,Simple (abstract algebra) ,Consistency (statistics) ,Fracture (geology) ,General Materials Science ,business - Abstract
Rate-independent finite elastoplastic equations with thermo-coupled effects are proposed to bypass the yield condition and loading–unloading conditions. These new equations are shown to be more realistic and of much simpler structure than classical equations. In a sense of thermodynamic consistency the strength property of elastoplastic solids is then studied from the standpoint of stress-bearing capacity. It is shown that asymptotic loss of the strength may be derived directly from elastoplastic equations, thus leading to the finding of a noticeable phenomenon, namely, asymptotic vanishing of the stress concurrent with developing elastoplastic flow. It is indicated that this finding may suggest a natural constitutive characterization of fatigue, fracture and failure as certain limiting cases of elastoplastic behavior. Simple models with asymptotic loss of the strength are constructed as examples of potential practical applications.
- Published
- 2014
- Full Text
- View/download PDF
50. BAG3 regulates epithelial–mesenchymal transition and angiogenesis in human hepatocellular carcinoma
- Author
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Jian Wu, Zheng Lv, Haiyang Xie, Rongliang Tong, Chengli Du, Shusen Zheng, Heng Xiao, Chaofeng Ding, Shaobing Cheng, and Lin Zhou
- Subjects
Male ,Vascular Endothelial Growth Factor A ,Carcinoma, Hepatocellular ,Epithelial-Mesenchymal Transition ,Angiogenesis ,Antigens, CD34 ,Apoptosis ,Vimentin ,Matrix metalloproteinase ,Pathology and Forensic Medicine ,Neovascularization ,Mice ,Cell Movement ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Neoplasm Invasiveness ,Epithelial–mesenchymal transition ,Extracellular Signal-Regulated MAP Kinases ,neoplasms ,Molecular Biology ,Adaptor Proteins, Signal Transducing ,Aged ,Cell Proliferation ,Gene knockdown ,Neovascularization, Pathologic ,biology ,Liver Neoplasms ,Cell Biology ,Middle Aged ,Hypoxia-Inducible Factor 1, alpha Subunit ,digestive system diseases ,Vascular endothelial growth factor A ,Gene Knockdown Techniques ,biology.protein ,Cancer research ,Heterografts ,Matrix Metalloproteinase 2 ,Female ,Signal transduction ,medicine.symptom ,Apoptosis Regulatory Proteins ,Signal Transduction - Abstract
Bcl2-associated athanogene 3 (BAG3) protein is a co-chaperone of heat-shock protein (Hsp) 70 and may regulate major physiological and pathophysiological processes. However, few reports have examined the role of BAG3 in human hepatocellular carcinoma (HCC). In this study, we show that BAG3 regulates epithelial-mesenchymal transition (EMT) and angiogenesis in HCC. BAG3 was overexpressed in HCC tissues and cell lines. BAG3 knockdown resulted in reduction in migration and invasion of HCC cells, which was linked to reversion of EMT by increasing E-cadherin expression and decreasing N-cadherin, vimentin and slug expression, as well as suppressing matrix metalloproteinase 2 (MMP-2) expression. In a xenograft tumorigenicity model, BAG3 knockdown effectively inhibited tumor growth and metastasis through reduction in CD34 and VEGF expression and reversal of the EMT pathway. In conclusion, BAG3 is associated with the invasiveness and angiogenesis in HCC, and the BAG3 gene may be a novel therapeutic approach against HCC.
- Published
- 2014
- Full Text
- View/download PDF
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