198 results on '"Yafei Hu"'
Search Results
152. Network Coding Based Link Scheduling for QoS Provisioning in Multi-radio and Multi-channel Wireless Mesh Networks
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Fangmin Li, Yafei Hu, and Xinhua Liu
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Wireless mesh network ,Computer science ,business.industry ,Network packet ,Wireless network ,Distributed computing ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Order One Network Protocol ,Wireless WAN ,Linear network coding ,Computer Science::Networking and Internet Architecture ,Maximum throughput scheduling ,Electrical and Electronic Engineering ,Radio resource management ,business ,Computer network - Abstract
This paper addresses Quality-of-Service (QoS) improvement in wireless mesh networks (WMNs) with multi-radio multi-channel by applying a novel network coding technique. It is known that network coding over wired networks enables connections at rates that cannot be achieved by traditional routings. However, the properties of wireless networks (e.g., omnidirectional transmissions, destructive interference, single transceiver per node, finite energy) modify the formulation of network coding and deviate from the classical network coding approach used in wired networks. In this paper, we investigate the problem of network-wide data transmission under the consideration of QoS requirements (namely packet delivery ratio, packet delay) over multi-radio and multi-channel WMNs. To solve this problem, we first introduce a network coding method, namely COPE, which is used to increase network-wide throughput for unicast wireless networks, and then present an Integer Linear Programming formulation of a given multi-radio and multi-channel WMN for addressing network coding traffic, routing, QoS requirements and scheduling optimizations. The proposed analytical formulation increases the network-wide throughput while satisfying the generalized QoS requirements by combining network coding strategy and interference free schedules. Our evaluations both in 16-node graph topology and 32-node random topology network show that a route selection strategy that is aware of network coding leads to higher in end-to-end throughput when compared to coding-oblivious routing strategies.
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- 2012
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153. Condition Evaluation of Asbestos Cement Water Mains
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Yafei Hu, Dunling Wang, and Rudaba Chowdhury
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carbonation ,Mains electricity ,Condition evaluation ,education ,Environmental engineering ,Asbestos cement ,acid attack ,Soil characteristics ,Visual inspection ,sulfate reaction ,pipe deterioration ,Asbestos cement (AC) water main ,Geographic regions ,Environmental science ,biodeterioration ,Water quality ,lime leaching - Abstract
This paper focuses on the condition evaluation of asbestos cement (AC) pipe samples from three utilities located in different geographic regions and climatic zones in the USA and Canada. Various means of examination or testing were used to evaluate the condition of the samples. These included visual inspection, hardness testing, phenolphthalein testing, crush testing, and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS). Climate and soil information was also collected for the areas where the three utilities are located to assess the external environments facing the AC pipes. The condition evaluation results were correlated with the external soil characteristics and internal water quality data, collected through a survey, to identify factors contributing to the deterioration of the AC pipes belonging to these utilities. The paper also discusses the variation in the deterioration of the AC water mains from the three utilities., American Society of Civil Engineering (ASCE) Pipeline 2012 Conference, August 19-22, 2012, Miami, Florida, U.S.A.
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- 2012
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154. Examination of Asbestos Cement Pipe Deterioration with Scanning Electron Microscopy
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Rudaba Chowdhury, Yafei Hu, and Dunling Wang
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Cement ,Ettringite ,Materials science ,Scanning electron microscope ,Carbonation ,education ,Metallurgy ,engineering.material ,Asbestos cement ,chemistry.chemical_compound ,chemistry ,engineering ,Leaching (metallurgy) ,Porosity ,Lime - Abstract
Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) microanalysis technique has distinct advantages in providing high resolution images for identification of microscopic structure changes in hydrated cement matrix and the chemical compositions. Therefore, this technique can be a very useful tool for characterization of asbestos cement (AC) pipe deterioration. Microscopic structural changes in AC pipes can be related to leaching, chemical and biological processes, which include the free lime leaching, secondary gypsum and ettringite formation, acid attack, and the microorganism induced deterioration. These processes have resulted in losses of free lime, cracks in cement matrix, dissolution of Ca-bearing minerals and increased porosity in the cement paste. Carbonation, as calcite precipitation, on the other hand, is more often observed on the outer surface of the pipe in an alkaline soil environment, and may help to protect AC pipes. This paper is focused on the SEM evidence of these deterioration processes. With the elemental composition data from EDX technique, SEM can be used to quantitatively evaluate AC pipe deterioration. A four stage of deterioration of AC pipes in drinking water distribution system is proposed based on the morphology and elemental compositions of the pipe samples. The understanding of degradation mechanisms provides a scientific basis for the development of operational practices and management strategies that can be used to extend the service life of AC pipes.
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- 2011
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155. PLC control system for dust removing system of carbon-produce lathing process
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Xiaochuan Li, Yafei Hu, and Qili Wang
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Energy conservation ,Engineering ,business.industry ,Control theory ,Control system ,Process (computing) ,Programmable logic controller ,Process control ,Control engineering ,Energy consumption ,business ,Automation ,Automotive engineering - Abstract
To reduce energy consumption and improve the level of automation of the system, based on analyzing and studying of dust removing system technological characteristics for carbon-produce lathing process, PLC control system of dust removing system has been ensured. Hardware composing and software function of control system has been built. The industry measure mathematics model has been put forward that is using the average velocity to measure the dust removing capacity, and the PID control algorithm to adjust the throttle intensity of the dust controller has been brought forward. Based on that, the effectual method for engineering actualizing and PLC control flow has been designed. Performance parameters, match with actual capacity, of dust removing system are set by control system automatically. Because of this control method, the energy consumption of dust catcher has been reduced about 35%. The application indicates that this control system is compact and credible. It helps to enhance corporation's automatization and management level and to improve environment lustration rate. It provides reference for auto-control of other dust removing.
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- 2011
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156. Pipe performance analysis with nonparametric regression
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Zheng Liu, Yafei Hu, and Wei Wu
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Mains electricity ,education ,Statistics ,Breakage rate ,Environmental science ,Failure data ,Condition assessment ,Working environment ,Asbestos cement ,Nonparametric regression - Abstract
Asbestos cement (AC) water mains were installed extensively in North America, Europe, and Australia during 1920s-1980s and subject to a high breakage rate in recent years in some utilities. It is essential to understand how the influential factors contribute to the degradation and failure of AC pipes. The historical failure data collected from twenty utilities are used in this study to explore the correlation between pipe condition and its working environment. In this paper, we applied four nonparametric regression methods to model the relationship between pipe failure represented by average break rates and influential variables including pipe age and internal and external working environmental parameters. The nonparametric regression models do not take a predetermined form but it needs information derived from data. The feasibility of using a nonparametric regression model for the condition assessment of AC pipes is investigated and understood.
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- 2011
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157. Condition Assessment Methods for AC Pipe and Current Practices
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Rudaba Chowdhury, Dunling Wang, and Yafei Hu
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Water mains ,education ,condition assessmetn ,Environmental science ,Conduites d'eau ,Current (fluid) ,water pipes ,asbestos cement pipes ,Condition assessment ,Reliability engineering - Abstract
Asbestos cement (AC) pipe was first introduced in North America in 1929 and became a common choice for potable water main construction from the 1940s to the 1970s. To understand the condition of AC pipe in North America, a survey was conducted that obtained information about AC pipe inventory, pipe conditions, working environments, rehabilitation/replacement methods, and safety and health-related management practices. This paper summarizes the AC condition assessment techniques used by the surveyed utilities. It also reviews other available condition assessment methods for AC pipes., ASCE Pipeline Conference 2010: 28 August 2010, Keystone, Colorado, USA
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- 2010
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158. Safety and Waste Management of Asbestos Cement Pipes
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Rudaba Chowdhury, Yafei Hu, and Dunling Wang
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safety procedures ,Water mains ,Waste management ,waste disposal ,education ,asbestos containing materials (ACM) ,surveillance questionnaire ,Environmental science ,Conduites d'eau ,Asbestos cement ,asbestos cement pipe - Abstract
Asbestos cement (AC) water mains, generally considered as non-friable asbestos-containing materials (ACMs), are not believed to represent a significant hazard to public health in normal use. However, repair, rehabilitation and removal of AC pipes involve cutting, polishing, and demolition can release asbestos fibers into the air, posing risks to public health. Many water utilities in North America currently have significant portions of their water mains composed of AC pipes. A comprehensive survey was conducted with 20 water utilities in the United States of America and Canada to understand the existing conditions of AC water mains in North America and to determine current management practices related to AC pipe repair, rehabilitation, and replacement. The survey was conducted through questionnaires that covered various areas: pipe inventory; environmental working conditions; current practices in pipe repair, rehabilitation and replacement; and safety/health protection practices used in working with, and disposing of AC pipe., ASCE Pipeline Conference 2010: 28 August 2010, Keystone, Colorado, USA
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- 2010
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159. AODV based on Vickrey Auction for wireless mesh networks
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Fangmin Li, Liu Xinhua, and Yafei Hu
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Routing protocol ,Dynamic Source Routing ,Wireless mesh network ,Computer science ,business.industry ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,TheoryofComputation_GENERAL ,Order One Network Protocol ,Metrics ,Ad hoc On-Demand Distance Vector Routing ,Vickrey auction ,business ,IEEE 802.11s ,Computer network - Abstract
In this paper, we propose routing protocol based on Vickrey Auction for selfish nodes in Wireless Mesh Networks. Our approach is to promote Vickrey Auction bidding to stimulate selfish nodes forwarding data packets in wireless mesh networks. A new routing metric is proposed to improve existed least-hop metric. Simulation results indicate that AODV-B reduces packet-loss rate at the expense of small delay.
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- 2010
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160. β-Benzene hexachloride induces apoptosis of rat Sertoli cells through generation of reactive oxygen species and activation of JNKs and FasL
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Haige Yu, Kedi Yang, Yafei Hu, Yang Song, Yu-Ping Wang, Xia Guan, Yinan Wang, Jin Cheng, Xianmin Liang, and Yuqin Shi
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Male ,Insecticides ,Fas Ligand Protein ,Health, Toxicology and Mutagenesis ,Caspase 3 ,Apoptosis ,Management, Monitoring, Policy and Law ,Toxicology ,Caspase 8 ,p38 Mitogen-Activated Protein Kinases ,Fas ligand ,Superoxide dismutase ,Rats, Sprague-Dawley ,Malondialdehyde ,medicine ,Animals ,Caspase ,chemistry.chemical_classification ,Reactive oxygen species ,Sertoli Cells ,biology ,Superoxide Dismutase ,Reproduction ,JNK Mitogen-Activated Protein Kinases ,NF-kappa B ,Transcription Factor RelA ,General Medicine ,Sertoli cell ,Cell biology ,Rats ,Enzyme Activation ,medicine.anatomical_structure ,chemistry ,biology.protein ,Environmental Pollutants ,Reactive Oxygen Species ,Hexachlorocyclohexane - Abstract
β-benzene hexachloride (β-BHC), the major metabolite of benzene-hexachloride (BHC), is a weak estrogen-like chemical. It is a known persistent organic pollutant and male reproductive toxicant. However, the mechanism by which β-BHC exposure causes male reproductive toxicity remains unknown. In the present study, rat Sertoli cells were used to investigate the molecular mechanism involved in β-BHC-induced toxicity in male reproductive system. The results indicated that β-BHC exposure at over 30 μM showed the induction of apoptotic cell death. β-BHC could induce elevation in reactive oxygen species (ROS) generation, increase in the leakage rate of LDH and MDA level, and decrease in SOD activity. In addition, there was an increase in the cellular levels of phospho-JNKs and FasL in the β-BHC-induced apoptosis; and a significant reduction of procaspase-3 and -8 was observed over 30-μM β-BHC treatment. The translocation of NF-κB enhanced with the increase of concentration of β-BHC. Furthermore, NAC administration, a scavenger of ROS, reversed β-BHC-induced apoptosis effects via inhibition of JNKs activation, FasL expression, and NF-κB translocation. These results lead us to speculate that ROS generation may play a critical role in the initiation of β-BHC-induced apoptosis by activation of the JNKs, translocation of NF-κB, expression of FasL, and further activation of caspase cascade.
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- 2009
161. Intelligent cable shovel excavation modeling and simulation
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Yafei Hu and Samuel Frimpong
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Engineering ,business.product_category ,business.industry ,Soil Science ,Excavation ,Civil engineering ,Excavation, mining, simulation, artificial intelligence ,Modeling and simulation ,Excavator ,Dynamic models ,Surface mining ,Shovel ,Astrophysics::Earth and Planetary Astrophysics ,business ,Working environment ,Mechanical energy ,Marine engineering - Abstract
Cable shovel excavators are used for primary production of geomaterials in many surface mining operations. A major problem in excavation is the variability of material diggability, resulting in varying mechanical energy input and stress loading of shovel dipper-and-tooth assembly across the working bench. This variability impacts the shovel dipper and tooth assembly in hard formations. In addition, the geometrical constraints within the working environment impose production limitations resulting in low production efficiency and high operating costs. An intelligent shovel excavation (ISE) technology has been proposed as a potential solution to these problems. This paper addresses the requirements of the dynamic models of the cable shovel underlying the ISE technology. The dynamic equations are developed using the Newton–Euler techniques. These models are validated with real-world data and simulated in a virtual prototype environment. The results provide the path trajectories, dynamic velocity and accelerat...
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- 2009
162. p,p′-DDE Induces Apoptosis of Rat Sertoli Cells via a FasL-Dependent Pathway
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Xia Guan, Jin Cheng, Yang Song, Yuqin Shi, Kedi Yang, Yafei Hu, Xianmin Liang, and Yinan Wang
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Male ,Antioxidant ,Health, Toxicology and Mutagenesis ,Metabolite ,medicine.medical_treatment ,lcsh:Medicine ,Apoptosis ,Fas ligand ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,reproductive and urinary physiology ,Caspase 8 ,Caspase 3 ,NF-kappa B ,food and beverages ,General Medicine ,Sertoli cell ,Cell biology ,medicine.anatomical_structure ,Toxicity ,Molecular Medicine ,Reproductive toxicity ,Research Article ,Propidium ,Signal Transduction ,Biotechnology ,endocrine system ,Fas Ligand Protein ,Article Subject ,Annexins ,Cell Survival ,Dichlorodiphenyl Dichloroethylene ,lcsh:Biotechnology ,Biology ,Models, Biological ,lcsh:TP248.13-248.65 ,Genetics ,medicine ,Animals ,RNA, Messenger ,Cell Shape ,Molecular Biology ,Messenger RNA ,Sertoli Cells ,organic chemicals ,lcsh:R ,Molecular biology ,Acetylcysteine ,Rats ,chemistry - Abstract
One,1-dichloro-2,2 bis(p-chlorophenyl) ethylene (p,p′-DDE), the major metabolite of 2,2-bis(4-Chlorophenyl)-1,1,1-trichloroethane (DDT), is a known persistent organic pollutant and male reproductive toxicant. It has antiandrogenic effect. However, the mechanism by which p,p′-DDE exposure causes male reproductive toxicity remains unknown. In the present study, rat Sertoli cells were used to investigate the molecular mechanism involved in p,p′-DDE-induced toxicity in male reproductive system. The results indicated that p,p′-DDE exposure at over 30 μM showed the induction of apoptotic cell death. p,p′-DDE could induce increases in FasL mRNA and protein, which could be blocked by an antioxidant agent, N-acetyl-l-cysteine (NAC). In addition, caspase-3 and -8 were activated by p,p′-DDE treatment in these cells. The activation of NF-κB was enhanced with the increase of p,p′-DDE dose. Taken together, these results suggested that exposure to p,p′-DDE might induce apoptosis of rat Sertoli cells through a FasL-dependent pathway.
- Published
- 2009
163. Instrumentation of a Section of AC Pipe in Expansive Soil
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Yafei Hu, Kaveh Lotfian, and Hung Q. Vu
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Section (archaeology) ,Expansive clay ,Geotechnical engineering ,Instrumentation (computer programming) ,Geology - Published
- 2008
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164. Mitochondrial Dysfunction in Cardiac Diseases and Therapeutic Strategies
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Yafei Huang and Bingying Zhou
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mitochondria ,cardiomyocytes ,cardiovascular diseases ,mitochondrial dysfunction ,therapeutic strategies targeting mitochondria ,Biology (General) ,QH301-705.5 - Abstract
Mitochondria are the main site of intracellular synthesis of ATP, which provides energy for various physiological activities of the cell. Cardiomyocytes have a high density of mitochondria and mitochondrial damage is present in a variety of cardiovascular diseases. In this paper, we describe mitochondrial damage in mitochondrial cardiomyopathy, congenital heart disease, coronary heart disease, myocardial ischemia–reperfusion injury, heart failure, and drug-induced cardiotoxicity, in the context of the key roles of mitochondria in cardiac development and homeostasis. Finally, we discuss the main current therapeutic strategies aimed at alleviating mitochondrial impairment-related cardiac dysfunction, including pharmacological strategies, gene therapy, mitochondrial replacement therapy, and mitochondrial transplantation. It is hoped that this will provide new ideas for the treatment of cardiovascular diseases.
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- 2023
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165. Managing the Risk of Critical Water Trunk Mains: A Municipal Perspective.
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Yafei Hu, Wenqing Yang, Chris Macey, Moncrieff, Michael, and Agha, Amir
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- 2016
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166. Oxidative stress, antioxidant status and DNA damage in patients with impaired glucose regulation and newly diagnosed Type 2 diabetes
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Wenbo Jia, Liegang Liu, Lin Lei, Xiufa Sun, Fangfang Song, Jie Lin, Ying Yao, and Yafei Hu
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Male ,medicine.medical_specialty ,Erythrocytes ,DNA damage ,Type 2 diabetes ,medicine.disease_cause ,Antioxidants ,Superoxide dismutase ,chemistry.chemical_compound ,Insulin resistance ,Diabetes mellitus ,Internal medicine ,Malondialdehyde ,Glucose Intolerance ,medicine ,Humans ,Glycated Hemoglobin ,biology ,Superoxide Dismutase ,General Medicine ,DNA ,Middle Aged ,medicine.disease ,Glutathione ,Comet assay ,Oxidative Stress ,Endocrinology ,Glucose ,chemistry ,Diabetes Mellitus, Type 2 ,biology.protein ,Female ,Insulin Resistance ,Oxidative stress ,DNA Damage - Abstract
Previous studies have postulated the association between oxidative stress and Type 2 diabetes. Considering the long pre-diabetic period with IGR (impaired glucose regulation) and its high risk of developing diabetes, to test this hypothesis, we have investigated oxidative stress pathways and DNA damage in patients with IGR and newly diagnosed Type 2 diabetes. The study population consisted of 92 subjects with NGT (normal glucose tolerance), 78 patients with IGR and 113 patients with newly diagnosed diabetes. Plasma MDA (malondialdehyde) and TAC (total antioxidative capacity) status, erythrocyte GSH content and SOD (superoxide dismutase) activity were determined. A comet assay was employed to evaluate DNA damage. Compared with subjects with NGT, patients with IGR had reduced erythrocyte SOD activity. Patients with diabetes had a higher plasma MDA concentration, but a lower plasma TAC level and erythrocyte SOD activity, than the NGT group. Correlation analysis revealed a strong positive association between IR (insulin resistance) and MDA concentration, but negative correlations with TAC status and SOD activity. With respect to β-cell function, a positive association with TAC status and an inverse correlation with GSH respectively, were observed. The comet assay revealed slight DNA damage in patients with IGR, which was increased in patients with diabetes. Significant correlations were observed between DNA damage and hyperglycaemia, IR and β-cell dysfunction. In conclusion, the results of the present study suggest that hyperglycaemia in an IGR state caused the predominance of oxidative stress over antioxidative defence systems, leading to oxidative DNA damage, which possibly contributed to pancreatic β-cell dysfunction, IR and more pronounced hyperglycaemia. This vicious circle finally induced the deterioration to diabetes.
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- 2007
167. Immune Deviation in the Decidua During Term and Preterm Labor
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Ying Zha, Haiyi Liu, Xingguang Lin, Long Yu, Peng Gao, Yuqi Li, Min Wu, Xun Gong, Xinyi Bian, Qi Kang, Pan Zhi, Xiaohe Dang, Jingyu Wang, Ling Feng, Fuyuan Qiao, Yafei Huang, and Wanjiang Zeng
- Subjects
decidua ,macrophage ,Th cells ,Treg cells ,term labor ,preterm labor ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The maternal-fetal immune disorder is considered to be an important factor of preterm birth (PTB); however, the underlying mechanism is still not fully understood. This study was designed to explore the innate and adaptive immune features in the decidua during term and preterm labor. Women delivered at term or preterm were classified into four groups: term not in labor (TNL, N=19), term in labor (TL, N=17), preterm not in labor (PNL, N=10), and preterm in labor (PIL, N=10). Decidua basalis and parietalis were collected and analyzed for macrophage subtypes (M1 and M2) as well as T helper 1 (Th1), Th2, Th17 and regulatory T (Treg) cells by flow cytometry and immunohistochemistry. Our results demonstrated significantly decreased frequencies of M2 cells and elevated M1/M2 ratio in the PIL group compared to that in the PNL group in both decidua basalis and parietalis, whereas no significant differences were found between the above two groups in both sites in terms of the polarization status of Th cells. On the contrary, macrophage subsets were comparable in the TL and TNL groups, whereas elevated Th1 percentages and Th1/Th2 ratio were observed in TL women compared to that in TNL women in the decidua. Interestingly, although the frequencies and ratios of Th17 and Treg were comparable among the four groups, the Th17/Treg ratios of these groups were significantly increased in decidua basalis than that in decidua parietalis. Collectively, the M1/M2 imbalance is associated with the breakdown of maternal-fetal immune tolerance during PTB, whereas the aberrant Th1/Th2 profile plays an important role in immune disorder during term labor. Moreover, Th17/Treg deviation is more remarkable in decidua basalis than in decidua parietalis.
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- 2022
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168. 212 Evaluation of Crack Initiation on Au Thin Film during Monotonic Tensile Loading
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Naoyuki Sato, Yafei Hu, Naoya Tada, Subuda Gerili, and Ichiro Shimizu
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- 2012
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169. Study of Wind Flow Angle and Velocity on Ice Accretion of Transmission Line Composite Insulators
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Yafei Huang, Muhammad S. Virk, and Xingliang Jiang
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Overhead transmission line ,CFD ,ice accretion ,insulator strings ,wind flow angle ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Ice accretion on insulators in cold regions is a serious and inevitable problem for power transmission lines, which may cause over-load and icing flashover accidents and can lead to wide power outage. In this research work, multiphase numerical simulations are carried out to investigate the effect of wind flow angle & velocity on the ice accretion of transmission line composite insulators. To verify the simulation results, lab-based icing tests are carried out in artificial climate chamber of Chongqing University. Results show that the change of wind flow angle has an obvious effect on both accreted ice shape and ice mass of insulators. When wind flow angle changes from 0° to 90° or -90°, the ice mass increases before dropping sharply. Meanwhile, ice mass accretion on insulators with wind flow angle is more sensitive to the change of wind velocity. For V-shape insulator strings, the ice mass increased 47.22% in average compared to ordinary suspension insulators. The findings of this research can provide significant engineering reference for the design of transmission line in icing prone areas.
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- 2020
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170. 1518 Observation of Deformation of Au Thin Film Deposited on Polycarbonate Substrate Subjected to Cyclic Loading
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Yafei Hu, Naoya Tada, Ichiro Shimizu, and Naoyuki Sato
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Materials science ,visual_art ,visual_art.visual_art_medium ,Cyclic loading ,Substrate (electronics) ,Composite material ,Thin film ,Deformation (meteorology) ,Polycarbonate - Published
- 2011
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171. Metabolic Molecule PLA2G2D Is a Potential Prognostic Biomarker Correlating With Immune Cell Infiltration and the Expression of Immune Checkpoint Genes in Cervical Squamous Cell Carcinoma
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Hong Liu, Ruiyi Xu, Chun Gao, Tong Zhu, Liting Liu, Yifan Yang, Haihong Zeng, Yafei Huang, and Hui Wang
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cervical squamous cell carcinoma ,PLA2G2D ,tumor immune microenvironment ,immune infiltration ,metabolism ,multiplex immunohistochemistry ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Cervical squamous cell carcinoma (CSCC) is the major pathological type of cervical cancer (CC), the second most prevalent reproductive system malignant tumor threatening the health of women worldwide. The prognosis of CSCC patients is largely affected by the tumor immune microenvironment (TIME); however, the biomarker landscape related to the immune microenvironment of CSCC and patient prognosis is less characterized. Here, we analyzed RNA-seq data of CSCC patients from The Cancer Genome Atlas (TCGA) database by dividing it into high- and low-immune infiltration groups with the MCP-counter and ESTIMATE R packages. After combining weighted gene co-expression network analysis (WGCNA) and differentially expressed gene (DEG) analysis, we found that PLA2G2D, a metabolism-associated gene, is the top gene positively associated with immune infiltration and patient survival. This finding was validated using data from The Cancer Genome Characterization Initiative (CGCI) database and further confirmed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Finally, multiplex immunohistochemistry (mIHC) was performed to confirm the differential infiltration of immune cells between PLA2G2D-high and PLA2G2D-low tumors at the protein level. Our results demonstrated that PLA2G2D expression was significantly correlated with the infiltration of immune cells, especially T cells and macrophages. More importantly, PLA2G2D-high tumors also exhibited higher infiltration of CD8+ T cells inside the tumor region than PLA2G2D-low tumors. In addition, PLA2G2D expression was found to be positively correlated with the expression of multiple immune checkpoint genes (ICPs). Moreover, based on other immunotherapy cohort data, PLA2G2D high expression is correlated with increased cytotoxicity and favorable response to immune checkpoint blockade (ICB) therapy. Hence, PLA2G2D could be a novel potential biomarker for immune cell infiltration, patient survival, and the response to ICB therapy in CSCC and may represent a promising target for the treatment of CSCC patients.
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- 2021
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172. 207 Deformation Analysis of Gold Thin Film on Polycarbonate Substrate Subjected to Thermal Change and Tensile Load by Finite Element Method
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Ichiro Shimizu, Yafei Hu, Naoya Tada, and Sibuda Gerili
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Materials science ,visual_art ,Thermal ,Ultimate tensile strength ,visual_art.visual_art_medium ,Substrate (electronics) ,Deformation (meteorology) ,Thin film ,Polycarbonate ,Composite material ,Finite element method - Published
- 2013
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173. Long-Term Clinical and Immunological Impact of Severe COVID-19 on a Living Kidney Transplant Recipient – A Case Report
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Liru Qiu, Ji Zhang, Yafei Huang, Gen Chen, Zhishui Chen, Changsheng Ming, Xia Lu, and Nianqiao Gong
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COVID-19 ,living kidney transplant ,lung injury ,renal tubular injury ,immunity ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The long-term impact of COVID-19 on transplant recipients remains unknown. We describe the case of a 30-year-old male kidney transplant recipient from Wuhan, China that was treated for severe COVID-19 in February 2020. He suffered an acute lung and renal injury and required systemic treatment including adjustment of his immunosuppressant regime. He was followed up to 1-year after discharge. No chronic lung fibrosis or deterioration of his pulmonary function was observed. Despite COVID-19 mediated damage to his renal tubular cells, no transplant rejection occurred. His immunological profile demonstrated both cellular anti-SARS-CoV-2 reactivity and specific humoral immunity, indicating that it is beneficial for the transplanted patients to be immunized with SARS-CoV-2 virus vaccine. This case will help guide clinical decision making for immunocompromised individuals that become infected with SARS-CoV-2.
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- 2021
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174. Neonatal LPS Administered Before Sensitization Reduced the Number of Inflammatory Monocytes and Abrogated the Development of OVA-Induced Th2 Allergic Airway Inflammation
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Liuchuang Gao, Min Wu, Hangyu Liu, Miao He, Han Jiang, Runshi Shang, Qiangqiang Wang, Zhu Song, Yafei Huang, and Junyan Han
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neonates ,time window ,LPS ,hygiene hypothesis ,allergic asthma ,Immunologic diseases. Allergy ,RC581-607 - Abstract
It is becoming increasingly clear that environment factors during early life play a pivotal role in the development of allergic asthma. Among these, a traditional farm is one of the strongest protective environments, and the protective effects have been, at least in part, attributed to the high-level exposure to lipopolysaccharide (LPS) on farms. However, the underlying mechanisms remain elusive, especially in ovalbumin (OVA)-induced neonatal allergic asthma model. Here, we used the OVA-induced asthma model in two age groups, neonatal and adult, when mice were first sensitized with peritoneal OVA/alum as neonates and adults, respectively. LPS was injected in the peritoneal cavity before OVA/alum sensitization. The effects of LPS treatment on allergic airway inflammation in the lung and the immune milieu in the peritoneal cavity were determined and compared between these two age groups. We found that LPS treatment abrogated the development of Th2 allergic airway responses in the neonatal group. In the adult group, the ameliorated Th2 allergic responses were accompanied with Th17 responses and neutrophil infiltration upon LPS treatment. We further investigated the immune milieu in the peritoneal cavity to elucidate the underlying mechanisms of this age-dependent difference. Our data show that in neonatal mice, LPS treatment significantly reduced the number of inflammatory monocytes in the peritoneal cavity. In the adult group, LPS treatment shifted the function of these cells which associated with Th1 and Th17 polarization. Our results provide more evidence that immunity in early life is distinct from that in adults, especially in the peritoneal cavity, and emphasize the importance of timing for the intervention of allergic asthma. Our results suggest that LPS treatment during early life is protective for the development of Th2 allergic responses. On the other hand, it might lead to a more severe phenotype of asthma when dampening the Th2 responses in adult mice.
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- 2021
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175. Activated γδ T Cells With Higher CD107a Expression and Inflammatory Potential During Early Pregnancy in Patients With Recurrent Spontaneous Abortion
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Long Yu, Yang Zhang, Jinfeng Xiong, Jianjun Liu, Ying Zha, Qi Kang, Pan Zhi, Qiang Wang, Hui Wang, Wanjiang Zeng, and Yafei Huang
- Subjects
γδ T cells ,recurrent spontaneous abortion (RSA) ,PD1 ,CD107a ,IL-17A ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Previous studies have reported the involvement of γδ T cells in recurrent spontaneous abortion (RSA); however, both pathogenic and protective effects were suggested. To interrogate the role of γδ T cells in RSA, peripheral blood from RSA patients and healthy women with or without pregnancy were analyzed for γδ T cells by flow cytometry (n = 9–11 for each group). Moreover, the decidua from pregnant RSA patients and healthy controls (RSA-P and HC-P group, respectively) was simultaneously stained for γδ T cells by immunohistochemistry (IHC) and bulk sequenced for gene expression. Our results demonstrated that the frequencies of peripheral γδ T cells and their subpopulations in RSA patients were comparable to that in healthy subjects, but the PD1 expression on Vδ2+ cells was increased in pregnant patients. Furthermore, peripheral Vδ2+ cells in RSA-P patients demonstrated significantly increased expression of CD107a, as compared to that in pregnant healthy controls. In addition, RSA-P patients had higher proportion of IL-17A-secreting but not IL-4-secreting Vδ2+ cells compared to the control groups. In decidua, an inflammatory microenvironment was also evident in RSA-P patients, in which CCL8 expression and the infiltration of certain immune cells were higher than that in the HC-P group, as revealed by transcriptional analysis. Finally, although the presence of γδ T cells in decidua could be detected during pregnancy in both RSA patients and healthy subjects by multicolor IHC analysis, the expression of CD107a on γδ T cells was markedly higher in the RSA-P group. Collectively, our results indicated that the increased activation, cytotoxicity, and inflammatory potential of peripheral and/or local γδ T cells might be responsible for the pathogenesis of RSA. These findings could provide a better understanding of the role of γδ T cells in RSA and shed light on novel treatment strategies by targeting γδ T cells for RSA patients.
- Published
- 2021
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176. Biomarkers and Immune Repertoire Metrics Identified by Peripheral Blood Transcriptomic Sequencing Reveal the Pathogenesis of COVID-19
- Author
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Yang Liu, Yankang Wu, Bing Liu, Youpeng Zhang, Dan San, Yu Chen, Yu Zhou, Long Yu, Haihong Zeng, Yun Zhou, Fuxiang Zhou, Heng Yang, Lei Yin, and Yafei Huang
- Subjects
SARS-CoV-2 ,transcriptomic characteristics ,IgG ,machine learning ,biomarker ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global crisis; however, our current understanding of the host immune response to SARS-CoV-2 infection remains limited. Herein, we performed RNA sequencing using peripheral blood from acute and convalescent patients and interrogated the dynamic changes of adaptive immune response to SARS-CoV-2 infection over time. Our results revealed numerous alterations in these cohorts in terms of gene expression profiles and the features of immune repertoire. Moreover, a machine learning method was developed and resulted in the identification of five independent biomarkers and a collection of biomarkers that could accurately differentiate and predict the development of COVID-19. Interestingly, the increased expression of one of these biomarkers, UCHL1, a molecule related to nervous system damage, was associated with the clustering of severe symptoms. Importantly, analyses on immune repertoire metrics revealed the distinct kinetics of T-cell and B-cell responses to SARS-CoV-2 infection, with B-cell response plateaued in the acute phase and declined thereafter, whereas T-cell response can be maintained for up to 6 months post-infection onset and T-cell clonality was positively correlated with the serum level of anti-SARS-CoV-2 IgG. Together, the significantly altered genes or biomarkers, as well as the abnormally high levels of B-cell response in acute infection, may contribute to the pathogenesis of COVID-19 through mediating inflammation and immune responses, whereas prolonged T-cell response in the convalescents might help these patients in preventing reinfection. Thus, our findings could provide insight into the underlying molecular mechanism of host immune response to COVID-19 and facilitate the development of novel therapeutic strategies and effective vaccines.
- Published
- 2021
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177. Corrigendum: Immune Phenotyping of Patients With Acute Vogt-Koyanagi-Harada Syndrome Before and After Glucocorticoids Therapy
- Author
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Han Jiang, Zhaohui Li, Long Yu, Ying Zhang, Li Zhou, Jianhua Wu, Jing Yuan, Mengyao Han, Tao Xu, Junwen He, Shan Wang, Chengfeng Yu, Sha Pan, Min Wu, Hangyu Liu, Haihong Zeng, Zhu Song, Qiangqiang Wang, Shen Qu, Junwei Zhang, Yafei Huang, and Junyan Han
- Subjects
immunopathogenesis ,lymphocyte subsets ,monocytes ,VKH ,autoimmunity ,cytokine ,Immunologic diseases. Allergy ,RC581-607 - Published
- 2021
- Full Text
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178. Immune Phenotyping of Patients With Acute Vogt-Koyanagi-Harada Syndrome Before and After Glucocorticoids Therapy
- Author
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Han Jiang, Zhaohui Li, Long Yu, Ying Zhang, Li Zhou, Jianhua Wu, Jing Yuan, Mengyao Han, Tao Xu, Junwen He, Shan Wang, Chengfeng Yu, Sha Pan, Min Wu, Hangyu Liu, Haihong Zeng, Zhu Song, Qiangqiang Wang, Shen Qu, Junwei Zhang, Yafei Huang, and Junyan Han
- Subjects
immunopathogenesis ,lymphocyte subsets ,monocytes ,VKH ,autoimmunity, cytokine ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Previous studies have established that disturbed lymphocytes are involved in the pathogenesis of Vogt-Koyanagi-Harada (VKH) syndrome. Accordingly, glucocorticoids (GCs), with their well-recognized immune-suppressive function, have been widely used for treatment of VKH patients with acute relapses. However, the systemic response of diverse immune cells to GC therapy in VKH is poorly characterized. To address this issue, we analyzed immune cell subpopulations and their phenotype, as well as cytokine profiles in peripheral blood from VKH patients (n=25) and health controls (HCs, n=21) by flow cytometry and luminex technique, respectively. For 16 patients underwent GC therapy (methylprednisolone, MP), the aforementioned measurements as well as the transcriptome data from patients before and after one-week’s GC therapy were also compared to interrogate the systemic immune response to GC therapy. Lymphocyte composition in the blood was different in VKH patients and HCs. VKH patients had significantly higher numbers of T cells with more activated, polarized and differentiated phenotype, more unswitched memory B cells and monocytes, as compared to HCs. MP treatment resulted in decreased frequencies of T cells and NK cells, inhibited NK cell activation and T cell differentiation, and more profoundly, a marked shift in the distribution of monocyte subsets. Collectively, our findings suggest that advanced activation and differentiation, as well as dysregulated numbers of peripheral lymphocytes are the major immunological features of VKH, and GC therapy with MP not only inhibits T cell activation directly, but also affects monocyte subsets, which might combinatorically result in the inhibition of the pathogenic immune response.
- Published
- 2021
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179. Examination of Asbestos Cement Pipe Deterioration with Scanning Electron Microscopy.
- Author
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Dunling Wang, Yafei Hu, and Chowdhury, Rudaba
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- 2011
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180. SAFETY AND WASTE MANAGEMENT OF ASBESTOS CEMENT PIPES.
- Author
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Dunling Wang, Yafei Hu, and Chowdhury, Rudaba
- Published
- 2010
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181. Condition Assessment Methods for AC Pipe and Current Practices.
- Author
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Yafei Hu, Dunling Wang, and Rudaba Chowdhury
- Published
- 2010
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182. AC Pipe in North America: Rehabilitation/Replacement Methods and Current Practices.
- Author
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Yafei Hu, Dunling Wang, Baker, Samar, and Cossitt, Karen
- Published
- 2009
- Full Text
- View/download PDF
183. Evaluation of different methods for gap filling of long‐term actual evapotranspiration time series measured by lysimeters
- Author
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Yafei Huang, Harrie‐Jan Hendricks Franssen, Michael Herbst, Martin Hirschi, Dominik Michel, Sonia I. Seneviratne, Adriaan J. Teuling, Roland Vogt, Schumacher Detlef, Thomas Pütz, and Harry Vereecken
- Subjects
Environmental sciences ,GE1-350 ,Geology ,QE1-996.5 - Abstract
Abstract Terrestrial evapotranspiration (ET) is the second largest water flux in the global water cycle. It can be measured with different techniques; weighable lysimeters can provide very accurate measurements, and some very long‐term time series exist. However, these lysimeter time series are affected by data gaps that must be filled to estimate actual ET totals and long‐term trends. In this paper, we explore four different gap‐filling methods: the potential ET‐method, the ratio method, the FAO‐based water balance method, and HYDRUS modeling. These gap‐filling methods were evaluated for three time series of actual ET measured by lysimeters and meteorological data of three European sites. Separate evaluations were made for the five driest and five wettest April–October periods to investigate whether the performance of the gap‐filling methods was affected by hydrological conditions. Series of random gaps were artificially created for the three time series, including gaps of four different lengths. Actual ET was estimated for these gaps with the gap‐filling methods, which were evaluated based on RMSE and mean bias error. The results show that the ratio method outperformed other methods for gap filling of lysimeter data for Basel (Switzerland), whereas the HYDRUS method outperformed other methods for Rheindahlen (Germany). For Rietholzbach (Switzerland), the different methods performed very similarly, except that the FAO method gives slightly larger RMSEs. The gap‐filling methods do not perform very differently for dry and wet conditions. The ratio method is recommended for filling smaller gaps, and the HYDRUS method is recommended for longer gaps of 30 d.
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- 2020
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184. Effect of Environmental Parameters on Streamer Discharge in Short Air Gap between Rod and Plate
- Author
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Xiaodong Ren, Xingliang Jiang, Guolin Yang, Yafei Huang, Jianguo Wu, and Zhongyi Yang
- Subjects
meteorological parameters ,short gap ,streamer discharge ,simulation analysis ,breakdown characteristics ,environment ,Technology - Abstract
Environmental meteorological parameters (temperature, humidity, air pressure, etc.) have an important impact on short gap streamer discharge. Based on the streamer theory and particle continuity equation of gas discharge, a short gap streamer discharge simulation model is established, and the influence of environmental parameters on the dynamic development process of streamer discharge is simulated and analyzed. The short gap air gap discharge characteristics were tested in a self-made gas discharge chamber. The results show that at low humidity (relative humidity 80%), with the increase of humidity, the electron density of the streamer channel decreases, the field strength of the streamer head decreases, the development speed of the streamer slows down, and the gap breakdown voltage increase. With a decrease of gas pressure, the electron density of the streamer channel decreases, the field strength of the streamer head decreases, the development speed of the streamer increases, and the gap breakdown voltage decreases; The temperature change has little effect on the streamer development process.
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- 2022
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185. β-benzene hexachloride induces apoptosis of rat sertoli cells through generation of reactive oxygen species and activation of JNKs and FasL.
- Author
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Yuqin Shi, Yang Song, Yuping Wang, Yinan Wang, Xianmin Liang, Yafei Hu, Haige Yu, Xia Guan, Jin Cheng, and Kedi Yang
- Subjects
HEXACHLOROBENZENE ,SERTOLI cells ,BENZENE ,REACTIVE oxygen species ,POLLUTANTS ,OXIDATIVE stress ,APOPTOSIS ,LABORATORY rats ,JNK mitogen-activated protein kinases ,PHYSIOLOGY - Abstract
β-benzene hexachloride (β-BHC), the major metabolite of benzene-hexachloride (BHC), is a weak estrogen-like chemical. It is a known persistent organic pollutant and male reproductive toxicant. However, the mechanism by which β-BHC exposure causes male reproductive toxicity remains unknown. In the present study, rat Sertoli cells were used to investigate the molecular mechanism involved in β-BHC-induced toxicity in male reproductive system. The results indicated that β-BHC exposure at over 30 μM showed the induction of apoptotic cell death. β-BHC could induce elevation in reactive oxygen species (ROS) generation, increase in the leakage rate of LDH and MDA level, and decrease in SOD activity. In addition, there was an increase in the cellular levels of phospho-JNKs and FasL in the β-BHC-induced apoptosis; and a significant reduction of procaspase-3 and -8 was observed over 30-μM β-BHC treatment. The translocation of NF-κB enhanced with the increase of concentration of β-BHC. Furthermore, NAC administration, a scavenger of ROS, reversed β-BHC-induced apoptosis effects via inhibition of JNKs activation, FasL expression, and NF-κB translocation. These results lead us to speculate that ROS generation may play a critical role in the initiation of β-BHC-induced apoptosis by activation of the JNKs, translocation of NF-κB, expression of FasL, and further activation of caspase cascade. © 2009 Wiley Periodicals, Inc. Environ Toxicol 26: 124-135, 2011. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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186. Evaluation of dielectric-based probes for expansive soils: application to Regina clay.
- Author
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Yafei Hu, Vu, Hung Q., and Hubble, David W.
- Subjects
DIELECTRIC devices ,SWELLING soils ,MATERIAL plasticity ,SOIL testing ,ELECTRIC properties of soils ,ELECTRONIC probes - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2010
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187. p,p'-DDE Induces Apoptosis of Rat Sertoli Cells via a FasL-Dependent Pathway.
- Author
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Yuqin Shi, Yang Song, Yinan Wang, Xianmin Liang, Yafei Hu, Xia Guan, Jin Cheng, and Yang, Kedi
- Subjects
APOPTOSIS ,CELL death ,SERTOLI cells ,LABORATORY rats ,ANTIOXIDANTS ,CHEMICAL inhibitors - Abstract
One,1-dichloro-2,2 bis(p-chlorophenyl) ethylene (p,p′-DDE), the major metabolite of 2,2-bis(4-Chlorophenyl)-1,1,1- trichloroethane (DDT), is a known persistent organic pollutant and male reproductive toxicant. It has antiandrogenic effect. However, the mechanism by which p,p′-DDE exposure causes male reproductive toxicity remains unknown. In the present study, rat Sertoli cells were used to investigate the molecular mechanism involved in p,p′-DDE-induced toxicity in male reproductive system. The results indicated that p,p′-DDE exposure at over 30 μM showed the induction of apoptotic cell death. p,p′-DDE could induce increases in FasL mRNA and protein, which could be blocked by an antioxidant agent, N-acetyl-l-cysteine (NAC). In addition, caspase-3 and -8 were activated by p,p′-DDE treatment in these cells. The activation of NF-κ?B was enhanced with the increase of p,p′-DDE dose. Taken together, these results suggested that exposure to p,p′-DDE might induce apoptosis of rat Sertoli cells through a FasL-dependent pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
188. Intelligent Cable Shovel Excavation Modeling and Simulation.
- Author
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Frimpong, Samuel and Yafei Hu
- Subjects
- *
EXCAVATING machinery , *ARCHAEOLOGICAL excavations , *MINES & mineral resources , *ARTIFICIAL intelligence , *DYNAMIC testing - Abstract
Cable shovel excavators are used for primary production of geomaterials in many surface mining operations. A major problem in excavation is the variability of material diggability, resulting in varying mechanical energy input and stress loading of shovel dipper-and-tooth assembly across the working bench. This variability impacts the shovel dipper and tooth assembly in hard formations. In addition, the geometrical constraints within the working environment impose production limitations resulting in low production efficiency and high operating costs. An intelligent shovel excavation (ISE) technology has been proposed as a potential solution to these problems. This paper addresses the requirements of the dynamic models of the cable shovel underlying the ISE technology. The dynamic equations are developed using the Newton–Euler techniques. These models are validated with real-world data and simulated in a virtual prototype environment. The results provide the path trajectories, dynamic velocity and acceleration profiles, and dimensioned parameters for optimum feed force, torques and momentum of shovel boom-dipper assembly for efficient excavation. The optimum digging forces and resistances for the cable shovel excavators are modeled and used to predict optimum excavation performance. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
189. Dynamic Modeling of Hydraulic Shovel Excavators for Geomaterials.
- Author
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Frimpong, Samuel, Yafei Hu, and Inyang, Hilary
- Subjects
- *
ARCHAEOLOGICAL excavations , *STRIP mining , *SHOVELS , *EXCAVATING machinery , *KINEMATICS , *MINING engineering - Abstract
The hydraulic shovel excavator has found significant applications in surface mining, construction, and geotechnical operations due to its flexibility and mobility. The key to high availability and utilization of this shovel is adequate understanding of machine dynamics and machine-formation interactions among other technical, operating, safety, and economic factors. These shovels are capital intensive, complex in design and operation within severely constrained environments. Detailed dynamic modeling and analysis are required to understand their effective utilization for achieving efficient operating performance and economic useful lives. Previous attempts at solving these problems are limited because they do not provide knowledge on the resistive forces and moments for efficient excavation. In this paper, the Newton-Euler techniques are used to develop hydraulic shovel dynamic models with numerical examples. Detailed analysis of the results shows that: (1) the kinematics of the stick-bucket joint (joint 3) is the most critical and effective control of this joint and is important input into efficient excavation design and execution; and (2) the highest resistive moments occur between the duration of 1.5 and 2.0 s after the start of formation excavation and the highest magnitudes are 1,500 Nm (for stick), 900 Nm (for bucket), and 600 Nm (for boom). Based on these results, the path trajectories, dynamic velocity and acceleration profiles, and dimensioned parameters for optimum feed force, torques, and momentum of shovel boom-bucket assembly can be modeled and used for efficient excavation. The optimum digging forces and resistances for the hydraulic shovel excavator can also be modeled and used to predict optimum excavation performance. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
190. Oxidative stress, antioxidant status and DNA damage in patients with impaired glucose regulation and newly diagnosed Type 2 diabetes.
- Author
-
Fangfang Song, Wenbo Jia, Ying Yao, Yafei Hu, Lin Lei, Jie Lin, Xiufa Sun, and Liegang Liu
- Subjects
OXIDATIVE stress ,DIABETES ,DNA ,FIRE assay - Abstract
Previous studies have postulated the association between oxidative stress and Type 2 diabetes. Considering the long pre-diabetic period with IGR (impaired glucose regulation) and its high risk of developing diabetes, to test this hypothesis, we have investigated oxidative stress pathways and DNA damage in patients with IGR and newly diagnosed Type 2 diabetes. The study population consisted of 92 subjects with NGT (normal glucose tolerance), 78 patients with IGR and 113 patients with newly diagnosed diabetes. Plasma MDA (malondialdehyde) and TAC (total antioxidative capacity) status, erythrocyte GSH content and SOD (superoxide dismutase) activity were determined. A comet assay was employed to evaluate DNA damage. Compared with subjects with NGT, patients with IGR had reduced erythrocyte SOD activity. Patients with diabetes had a higher plasma MDA concentration, but a lower plasma TAC level and erythrocyte SOD activity, than the NGT group. Correlation analysis revealed a strong positive association between IR (insulin resistance) and MDA concentration, but negative correlations with TAC status and SOD activity. With respect to β-cell function, a positive association with TAC status and an inverse correlation with GSH respectively, were observed. The comet assay revealed slight DNA damage in patients with IGR, which was increased in patients with diabetes. Significant correlations were observed between DNA damage and hyperglycaemia, IR and β-cell dysfunction. In conclusion, the results of the present study suggest that hyperglycaemia in an IGR state caused the predominance of oxidative stress over antioxidative defence systems, leading to oxidative DNA damage, which possibly contributed to pancreatic β-cell dysfunction, IR and more pronounced hyperglycaemia. This vicious circle finally induced the deterioration to diabetes. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
191. An educational intervention to increase awareness reduces unnecessary laboratory testing in an internal medicine resident-run clinic
- Author
-
Erika Leung, Shuang Song, Omar Al-Abboud, Shahed Shams, John English, Wisam Naji, Yafei Huang, Leon Robison, Fred Balis, and Hameem I. Kawsar
- Subjects
Laboratory testing ,cost reduction ,behavior modification ,residency ,educational intervention ,patient care ,Internal medicine ,RC31-1245 - Abstract
At our resident-run clinic in an underserved community, laboratory test costs in 2013 exceeded the government subsidy by $400 000. To optimize limited resources and improve patient care, an education program to reduce testing was implemented. Between November 2014 and January 2015, residents attended lectures on utilization of laboratory testing, focusing on standard practice guidelines, and analyses of unnecessary tests. Multivariate nonparametric statistical methods and subgroup analysis were used to evaluate cost reduction. There were 453 clinic visits during the intervention period and 471 visits during the control period. Lectures were independently associated with a significant laboratory cost reduction. Median laboratory cost per visit decreased from $106.00 to $74.00. Total cost in the study period decreased from $79 403 to $51 463. There were similar reductions of laboratory costs in two subgroups: age groups of
- Published
- 2017
- Full Text
- View/download PDF
192. Deformation Behavior of an Epoxy Resin Subject to Multiaxial Loadings. Part II: Constitutive Modeling and Predictions.
- Author
-
Yafei Hu, Zihui Xia, and Ellyin, Fernand
- Subjects
DEFORMATIONS (Mechanics) ,EPOXY resins ,POLYMERS - Abstract
Part II. Describes the improved nonlinear viscoelastic constitutive model for the deformation behavior of an epoxy resin. Strength evaluation of the polymeric structures; Effect of hydrostatic pressure on the deformation behavior of polymers; Comparison of the behavior between uniaxial tension and compression.
- Published
- 2003
- Full Text
- View/download PDF
193. An Experimental Investigation of Normal and Shear Stress Interaction of an Epoxy Resin and Model....
- Author
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Yafei Hu, Ellyin, Fernand, and Zihui Xia
- Subjects
EPOXY resins ,SHEAR (Mechanics) ,POLYMERS - Abstract
Investigates the axial-torsional interaction of an epoxy resin by subjecting thin-walled tubular specimens. Effects of superposed shear stress on the normal stress response of the resin; Examination on the two nonlinear viscoelastic constitutive models; Differences in the transient stress response.
- Published
- 2001
- Full Text
- View/download PDF
194. γδ T cells shape memory-phenotype αβ T cell populations in non-immunized mice.
- Author
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Swati Popat Phalke, Yafei Huang, Kira Rubtsova, Andrew Getahun, Deming Sun, Richard L Reinhardt, Rebecca L O'Brien, and Willi K Born
- Subjects
Medicine ,Science - Abstract
Size and composition of γδ T cell populations change dramatically with tissue location, during development, and in disease. Given the functional differentiation of γδ T cell subsets, such shifts might alter the impact of γδ T cells on the immune system. To test this concept, and to determine if γδ T cells can affect other immune cells prior to an immune response, we examined non-immunized mice derived from strains with different genetically induced deficiencies in γδ T cells, for secondary changes in their immune system. We previously saw extensive changes in pre-immune antibodies and B cell populations. Here, we report effects on αβ T cells. Similarly to the B cells, αβ T cells evidently experience the influence of γδ T cells at late stages of their pre-immune differentiation, as single-positive heat stable antigen-low thymocytes. Changes in these and in mature αβ T cells were most prominent with memory-phenotype cells, including both CD8+ and CD4+ populations. As previously observed with B cells, most of the effects on αβ T cells were dependent on IL-4. Unexpectedly, IL-4 seemed to be produced mainly by αβ T cells in the non-immunized mice, albeit strongly regulated by γδ T cells. Similarly to our findings with B cells, changes of αβ T cells were less pronounced in mice lacking all γδ T cells than in mice lacking only some, suggesting that the composition of the γδ T cell population determines the nature of the γδ-influence on the other pre-immune lymphocytes.
- Published
- 2019
- Full Text
- View/download PDF
195. A Lateral Flow Strip Based Aptasensor for Detection of Ochratoxin A in Corn Samples
- Author
-
Guilan Zhang, Chao Zhu, Yafei Huang, Jiao Yan, and Ailiang Chen
- Subjects
aptamer ,lateral flow strip ,detection ,Ochratoxin A ,corn samples ,Organic chemistry ,QD241-441 - Abstract
Ochratoxin A (OTA) is a mycotoxin identified as a contaminant in grains and wine throughout the world, and convenient, rapid and sensitive detection methods for OTA have been a long-felt need for food safety monitoring. Herein, we presented a new competitive format based lateral flow strip fluorescent aptasensor for one-step determination of OTA in corn samples. Briefly, biotin-cDNA was immobilized on the surface of a nitrocellulose filter on the test line. Without OTA, Cy5-labeled aptamer combined with complementary strands formed a stable double helix. In the presence of OTA, however, the Cy5-aptamer/OTA complexes were generated, and therefore less free aptamer was captured in the test zone, leading to an obvious decrease in fluorescent signals on the test line. The test strip showed an excellent linear relationship in the range from 1 ng·mL−1 to 1000 ng·mL−1 with the LOD of 0.40 ng·mL−1, IC15 value of 3.46 ng·mL−1 and recoveries from 96.4% to 104.67% in spiked corn samples. Thus, the strip sensor developed in this study is an acceptable alternative for rapid detection of the OTA level in grain samples.
- Published
- 2018
- Full Text
- View/download PDF
196. Molecular and Biochemical Analysis of Chalcone Synthase from Freesia hybrid in flavonoid biosynthetic pathway.
- Author
-
Wei Sun, Xiangyu Meng, Lingjie Liang, Wangshu Jiang, Yafei Huang, Jing He, Haiyan Hu, Jonas Almqvist, Xiang Gao, and Li Wang
- Subjects
Medicine ,Science - Abstract
Chalcone synthase (CHS) catalyzes the first committed step in the flavonoid biosynthetic pathway. In this study, the cDNA (FhCHS1) encoding CHS from Freesia hybrida was successfully isolated and analyzed. Multiple sequence alignments showed that both the conserved CHS active site residues and CHS signature sequence were found in the deduced amino acid sequence of FhCHS1. Meanwhile, crystallographic analysis revealed that protein structure of FhCHS1 is highly similar to that of alfalfa CHS2, and the biochemical analysis results indicated that it has an enzymatic role in naringenin biosynthesis. Moreover, quantitative real-time PCR was performed to detect the transcript levels of FhCHS1 in flowers and different tissues, and patterns of FhCHS1 expression in flowers showed significant correlation to the accumulation patterns of anthocyanin during flower development. To further characterize the functionality of FhCHS1, its ectopic expression in Arabidopsis thaliana tt4 mutants and Petunia hybrida was performed. The results showed that overexpression of FhCHS1 in tt4 mutants fully restored the pigmentation phenotype of the seed coats, cotyledons and hypocotyls, while transgenic petunia expressing FhCHS1 showed flower color alteration from white to pink. In summary, these results suggest that FhCHS1 plays an essential role in the biosynthesis of flavonoid in Freesia hybrida and may be used to modify the components of flavonoids in other plants.
- Published
- 2015
- Full Text
- View/download PDF
197. Diurnal patterns of soluble amyloid precursor protein metabolites in the human central nervous system.
- Author
-
Justyna A Dobrowolska, Tom Kasten, Yafei Huang, Tammie L S Benzinger, Wendy Sigurdson, Vitaliy Ovod, John C Morris, and Randall J Bateman
- Subjects
Medicine ,Science - Abstract
The amyloid-β (Aβ) protein is diurnally regulated in both the cerebrospinal fluid and blood in healthy adults; circadian amplitudes decrease with aging and the presence of cerebral Aβ deposits. The cause of the Aβ diurnal pattern is poorly understood. One hypothesis is that the Amyloid Precursor Protein (APP) is diurnally regulated, leading to APP product diurnal patterns. APP in the central nervous system is processed either via the β-pathway (amyloidogenic), generating soluble APP-β (sAPPβ) and Aβ, or the α-pathway (non-amyloidogenic), releasing soluble APP-α (sAPPα). To elucidate the potential contributions of APP to the Aβ diurnal pattern and the balance of the α- and β- pathways in APP processing, we measured APP proteolytic products over 36 hours in human cerebrospinal fluid from cognitively normal and Alzheimer's disease participants. We found diurnal patterns in sAPPα, sAPPβ, Aβ40, and Aβ42, which diminish with increased age, that support the hypothesis that APP is diurnally regulated in the human central nervous system and thus results in Aβ diurnal patterns. We also found that the four APP metabolites were positively correlated in all participants without cerebral Aβ deposits. This positive correlation suggests that the α- and β- APP pathways are non-competitive under normal physiologic conditions where APP availability may be the limiting factor that determines sAPPα and sAPPβ production. However, in participants with cerebral Aβ deposits, there was no correlation of Aβ to sAPP metabolites, suggesting that normal physiologic regulation of cerebrospinal fluid Aβ is impaired in the presence of amyloidosis. Lastly, we found that the ratio of sAPPβ to sAPPα was significantly higher in participants with cerebral Aβ deposits versus those without deposits. Therefore, the sAPPβ to sAPPα ratio may be a useful biomarker for cerebral amyloidosis.
- Published
- 2014
- Full Text
- View/download PDF
198. COVID-19 control strategies in Taizhou city, China.
- Author
-
Haijiang Lin, Congcong Guo, Yafei Hu, Hongbiao Liang, Weiwei Shen, Wenhui Mao, and Na He
- Subjects
- *
PREVENTION of infectious disease transmission , *PREVENTION of communicable diseases , *INTERPROFESSIONAL relations , *CONTACT tracing , *COVID-19 , *SOCIAL distancing , *STAY-at-home orders - Abstract
Problem On 21 January 2020, the city of Taizhou, China, reported its first imported coronavirus disease 2019 (COVID-19) case and subsequently the number of cases rapidly increased. Approach To organize the emergency responses, the government of Taizhou established on 23 January 2020 novel headquarters for prevention and control of the COVID-19 outbreak, by coordinating different governmental agencies. People at high risk of acquiring COVID-19, as well as probable and confirmed cases, were identified and quarantined. The government closed public venues and limited gatherings. The Taizhou Health Commission shared information about identified COVID-19 patients and probable cases with affected agencies. To timely track and manage close contacts of confirmed cases, Taizhou Center for Disease Control and Prevention did epidemiological investigations. Medical institutions or local centers for disease control and prevention reported confirmed cases to the national Center for Disease Control and Prevention. Local setting Taizhou, a city in Zhejiang province with about 6 million residents, reported 18 confirmed COVID-2019 cases by 23 January 2020, which ranked it third globally in number of cases after Wuhan and Xiaogan cities in the Hubei province. Relevant changes In total, 146 confirmed cases (85 cases imported and 61 cases through community transmission) and no deaths due to COVID-19 had been reported in Taizhou by 1 June 2020. Between 16 February and 1 June 2020, no confirmed case had been reported. Lesson learnt Identifying and managing imported cases and people at risk for infection, timely information sharing, limiting gatherings and ensuring collaborations between different agencies were important in controlling COVID-19. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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