225 results on '"Tian, Wenhong"'
Search Results
202. Analysis and efficient provisioning of access networks with correlated and bursty arrivals.
- Author
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Tian, Wenhong
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ACCESS control of computer networks , *DISCRETE-time systems , *ASYNCHRONOUS transfer mode , *CONTINUOUS time systems , *INTERNET servers , *POISSON processes - Abstract
SUMMARY The statistical multiplexer problem was analyzed extensively in the discrete-time case within the context of ATM access networks or Internet. Despite the vast literature on ATM multiplexer, this problem has not been satisfactorily analyzed in the continuous-time case. In this paper, a statistical multiplexer consisting of a single server queue is modeled and analyzed. N identical interrupted Poisson process arrivals flow into the multiplexer are considered, the service time is assumed to be exponentially distributed, and the queue size is infinite. We developed an efficient way to approximate the superposition of n interrupted Poisson process (or n MMPP 2) arrival process by an MMPP 2 through moments and index of dispersion count (IDC) matching. We then find the closed-form Laplace transform of the departure process of an MMPP 2/M/1 queue. Our results prove that the departure process of an MMPP 2/M/1 queue is not an MMPP 2, which closes the long open problem that whether the departure process of an MMPP/M/1 can be a MMPP. Using Laplace transform matching, we approximated the departure process of an MMPP 2/M/1 by an MMPP 2. These results permit us to analyze a number of statistical multiplexer linked in series as they arise in an access network. Numerical experiments show that approximate analytical results match the simulation results very well. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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203. Long-term ex vivomonitoring of in vivomicroRNA activity in liver using a secreted luciferase sensor
- Author
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Wang, Gang, Dong, XiaoYan, Hu, JianYang, Tian, WenHong, Yuchi, Jie, Wang, Yue, and Wu, XiaoBing
- Abstract
Technology for monitoring in vivomicroRNA (miRNA) activity is extremely important for elucidating miRNA biology. However, in vivostudies of miRNA have been hampered by the lack of a convenient approach to reliably reflect real-time functional changes in miRNAs. Sensors for miRNA were developed by adding miRNA target sequences to the 3′-untranslated region of Gaussia princepsluciferase (Gluc) mRNA. These sensors were then evaluated in vitroand in vivoby measuring Gluc activity in cell supernatants and in peripheral blood. Sensors driven by the CMV promoter were effective for monitoring miR-122 in living cells, but not for the long-term monitoring of miR-122 or miR-142 in mouse liver because of CMV-promoter silencing. Replacing the CMV promoter with a CAG promoter rendered these sensors effective for the long-term monitoring of relevant liver miRNA activities. We subsequently used the CAG-promoter-based sensor for the long-term monitoring of endogenous liver miR-122, miR142 and miR-34a activities, as well as for exogenous miR-34a activity. Our study demonstrates that real-time in vivoactivities of miRNAs can be continuously and conveniently detected in mouse liver using the sensors that we have developed.
- Published
- 2011
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204. Analytical Models and Efficient Dimensioning Algorithms for Communication Systems In Randomly Changing Traffic Environments
- Author
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Tian, Wenhong
- Subjects
- Randomly Changing Traffic Environments, Communication Systems, Efficient Dimensioning Algorithms, Analytical Models
- Abstract
Analysis and design of communication systems in today's dynamically changing environment face a lot of challenges. Communication systems are not static but are dynamically changing today. Networks can become overloaded at one moment and underutilized at the next. Humans simply cannot respond to changes fast enough; computer programs must be used. Queueing theory has typically been used to address queueing problems of communication networks under the assumption that the inter-arrival times and the service times are renewal processes, and the arrival rate and bandwidth requirement of each customer is constant. In today's dynamically changing environment, such as in high-speed integrated-services wired and wireless networks and Web service, these assumptions are frequently unjustified. Our research focuses on the performance evaluation and efficient resource dimensioning algorithms of communication systems in a dynamically changing environment. The topics investigated are either new or they have not been studied well in the literature. One of our contributions is providing efficient dimensioning algorithms in closed-form with a constant or near linear complexity. In this thesis, we considered the following cases: a) the arrival rates of customers are time-varying, b) the bandwidth requirement of a customer is variable, c) integrated streaming and data traffic where the available bandwidth for the data traffic is dynamically changing and d) a statistical multiplexer with autocorrelated and bursty arrival processes. This work starts with the dynamic analysis and design of a communication link when the arrivals are time-varying. The time-varying arrivals capture the nature of a dynamic traffic environment. Using transient analysis, we dimension a link under time-varying arrivals and transient load. We compare some methods (both numerical and closed-form) in the literature and propose efficient ways to design the system under study. We next consider the case when the customer's bandwidth requirements are time-varying. A multi-rate loss model with class-change is proposed and the blocking probability is calculated using an iterative recursive formula. The optimal dimensioning of the capacity of this system is obtained using a formula with a constant cost. Subsequently we consider a model to analyze the integrated streaming traffic and data traffic, where the data traffic is bursty with a time-varying bandwidth shared with the streaming traffic. Using priority decomposition, we proposed closed-form solution for dimensioning of both streaming and data traffic. Finally we analyze a statistical multiplexer in a packet-switched network where the arrival process is the superposition of n independent identical bursty and autocorrelated arrival processes. We construct the superposition of these arrival processes and characterize the departure process from the multiplexer by exact Laplace transform for the first time and a two-stage Markov-modulated Poisson process. These results permit us to analyze and dimension the system more efficiently under study.
- Published
- 2009
205. A frequency-aware and energy-saving strategy based on DVFS for Spark.
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Li, Hongjian, Wei, Yaojun, Xiong, Yu, Ma, Enjie, and Tian, Wenhong
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DATA processing service centers , *ENERGY consumption , *BIG data , *ELECTRONIC data processing , *ALGORITHMS , *CONSUMPTION (Economics) , *SPARK ignition engines - Abstract
With the fast growth of big data applications, it has brought about a huge increase in the energy consumption for big data processing in Cloud data centers. In this study, a frequency-aware and energy-saving strategy based on dynamic voltage and frequency scaling (abbreviated as FAESS-DVFS) is proposed to reduce energy consumption for big data processing in Spark on YARN. Energy saving in two layers (YARN layer and Spark layer) has been designed and implemented for the proposed method. First, an optimal CPU frequency is presented in YARN layer based on the minimum energy efficiency ratio (EER) which can be obtained from status monitoring module. Then, a task scheduling method in Spark layer is constructed to optimize the energy consumption by dynamically adjusting the CPU frequency of nodes in the life cycle of different stages. Test on Hibench, the proposed method can achieve substantial energy saving of up to 29.5% for big data processing compared with the default algorithm in Spark on YARN while satisfying SLA constrains. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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206. Finite-time [formula omitted] reliable control for T–S fuzzy systems with variable sampling.
- Author
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Luo, Jinnan, Liu, Xinzhi, Tian, Wenhong, Zhong, Shouming, Shi, Kaibo, and Li, Mengling
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FUZZY control systems , *FUZZY systems , *TRUCK trailers , *SAMPLING (Process) - Abstract
This work mainly concentrates on the finite-time H ∞ reliable control for T–S fuzzy systems with aperiodic sampling. By considering the information of the state, an improved Lyapunov–Krasovskii functional (LKF) is structured. Moreover, based on free-weighted method and aperiodic sampling techniques, further criteria are proposed to guarantee that the T–S fuzzy systems is finite-time stabilization with H ∞ performance. Meanwhile, the H ∞ reliable controller is designed with larger sampling interval. Finally, the advantages of the obtained results are affirmed by a truck–trailer system. • The effect of aperiodic sampling on T–S fuzzy systems is studied. • An improved Lyapunov–Krasovskii functional is constructed in the study. • The modified H ∞ reliable controller schemes are designed. • Sufficient conditions for the finite-time bounded are obtained. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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207. An energy-aware scheduling algorithm for big data applications in Spark.
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Li, Hongjian, Wang, Huochen, Fang, Shuyong, Zou, Yang, and Tian, Wenhong
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ALGORITHMS , *SERVICE level agreements , *ENERGY consumption , *BIG data , *FIRST in, first out (Queuing theory) - Abstract
Energy consumption is explosive increasing with the fast growth of big data applications. High carbon emissions from big data platforms have serious impacts on environment. In this paper, we propose an energy-aware scheduling algorithm for Spark (EASAS) to reduce energy consumption while satisfying the service level agreement (SLA). First, we present a new energy consumption model based on Spark framework. Then a strategy table for the relationship between tasks and executors is designed to record the execution time and energy consumption of tasks. The task scheduling in Spark is conducted and optimized based on the strategy table. The proposed strategy overcomes the defect of the default scheduling strategy FIFO and FAIR which cannot perceive energy consumption with the characteristics of energy consumption perception and dynamic optimization scheduling. Compared against FIFO and FAIR, Our EASAS effectively reduces on average about 25–40% of the total energy consumption of Spark applications under deadline constrains. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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208. SAVE: self-adaptive consolidation of virtual machines for energy efficiency of CPU-intensive applications in the cloud.
- Author
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Guo, Wenxia, Kuang, Ping, Jiang, Yaqiu, Xu, Xiang, and Tian, Wenhong
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ENERGY consumption , *SELF-adaptive software , *VIRTUAL machine systems , *NP-complete problems , *MACHINING , *SERVER farms (Computer network management) , *SAVINGS - Abstract
In virtualized data centers, consolidation of virtual machines (VMs) on minimizing the number of total physical machines (PMs) has been recognized as a very efficient approach. This paper considers the energy-efficient consolidation of VMs in a cloud datacenter. Concentrating on CPU-intensive applications, the objective is to schedule all requests non-preemptively, subjecting to constraints of PM capacities and running time interval spans, to make the total energy consumption of all PMs is minimized (called MinTE for abbreviation). The MinTE problem is NP-complete in general. We propose a self-adaptive approach called SAVE. The approach makes decisions of the assignment and migration of VMs by probabilistic processes and is based exclusively on local information. Both simulation and real environment test show that our proposed method SAVE can reduce energy consumption about 30 % against VMWare DRS and 10–20% against ecoCloud on average. Extensive experiments show that our method outperforms the existing method and achieves significant energy savings and high utilization. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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209. Stabilization analysis for fuzzy systems with a switched sampled-data control.
- Author
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Luo, Jinnan, Li, Mengling, Liu, Xinzhi, Tian, Wenhong, Zhong, Shouming, and Shi, Kaibo
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DISCRETE-time systems , *SYSTEM analysis , *FUZZY control systems , *MEMBERSHIP functions (Fuzzy logic) , *FUZZY systems - Abstract
This study focuses on the stabilization analysis for fuzzy systems with the switched sampled-data control. By utilizing the information of the membership functions, an improved time-dependent and fuzzy-membership-function-dependent Lyapunov–Krasovskii functional (LKF) is constructed to commendably capture the available information related to the real sampling pattern. Together with a switching idea and newly inequalities, further results with less conservativeness are established to ensure that the switched sampled-data control stabilizes the fuzzy systems. Moreover, the switched sampled-data controllers are devised with a larger sampling interval. Finally, the effectiveness of the presented criteria is verified by two examples. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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210. Energy-efficient and QoS-aware model based resource consolidation in cloud data centers.
- Author
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Li, Hongjian, Zhu, Guofeng, Zhao, Yuyan, Dai, Yu, and Tian, Wenhong
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CLOUD storage , *DATA libraries , *ENERGY consumption , *SERVER farms (Computer network management) , *CLOUD computing , *COMPUTER algorithms , *VIRTUAL machine systems - Abstract
High energy consumption in data center has become a key problem, and the Carbon (CO $$_2$$ ) emissions from data center have serious impacts on environment. To improve traditional performance-energy model and minimize energy consumption in cloud data center, an energy-efficient and QoS-aware (EEQoS) model is developed for virtual resources consolidation. The EEQoS model is designed to investigate the trade-off between energy and QoS. The user's satisfaction degree and Euclidean distance of resources are also respectively applied to the QoS model and power model. In addition, this EEQoS model is combined with the particle swarm optimization algorithm by setting the power consumption per QoS value as the objective function to consolidate virtual resources in data center. Compared with traditional power model, the proposed model reduces response time by 27.2%, cost by 31.4%, SLA violations by 40.5% and improves throughput by 13.5% on average while increasing less than 3.8% energy consumption during the whole test period. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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211. A distributed coevolutionary algorithm for multiobjective hybrid flowshop scheduling problems.
- Author
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Su, Sheng, Yu, Haijie, Wu, Zhenghua, and Tian, Wenhong
- Subjects
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PRODUCTION scheduling , *EVOLUTIONARY algorithms , *MULTIPLE criteria decision making , *PROBLEM solving , *COMPUTATIONAL complexity , *MULTIAGENT systems - Abstract
A distributed coevolutionary algorithm is proposed to solve the multiobjective hybrid flowshop scheduling problems to minimize the maximum completion time and total tardiness of jobs. The framework of the distributed coevolutionary algorithm consists of a global agent and multiple local agents. The global agent and local agents evolve independently and cooperate by interchanging a selected solution list. Unlike the cooperative coevolutionary algorithms in the literature, the proposed algorithm does not decompose the scheduling problem and executes evolutionary operations based on the whole solution of the problem in all the agents. SPEA2 is the core components in the local agents. Path relinking is applied in order to implement the evolutionary computation among non-dominated solutions in the global agent. We analyzed the time complexity of the proposed algorithm. To evaluate the performance against the benchmark of multiobjective evolutionary algorithms, it is tested on a large number of computational instances. The computational experiments show the proposed distributed coevolutionary algorithm can obtain better solution quality than other algorithms within given computational time. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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212. Facial expression recognition (FER) survey: a vision, architectural elements, and future directions.
- Author
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Ullah S, Ou J, Xie Y, and Tian W
- Abstract
With the cutting-edge advancements in computer vision, facial expression recognition (FER) is an active research area due to its broad practical applications. It has been utilized in various fields, including education, advertising and marketing, entertainment and gaming, health, and transportation. The facial expression recognition-based systems are rapidly evolving due to new challenges, and significant research studies have been conducted on both basic and compound facial expressions of emotions; however, measuring emotions is challenging. Fueled by the recent advancements and challenges to the FER systems, in this article, we have discussed the basics of FER and architectural elements, FER applications and use-cases, FER-based global leading companies, interconnection between FER, Internet of Things (IoT) and Cloud computing, summarize open challenges in-depth to FER technologies, and future directions through utilizing Preferred Reporting Items for Systematic reviews and Meta Analyses Method (PRISMA). In the end, the conclusion and future thoughts are discussed. By overcoming the identified challenges and future directions in this research study, researchers will revolutionize the discipline of facial expression recognition in the future., Competing Interests: The authors declare there are no competing interests., (©2024 Ullah et al.)
- Published
- 2024
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213. Small-Scale and Occluded Pedestrian Detection Using Multi Mapping Feature Extraction Function and Modified Soft-NMS.
- Author
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Assefa AA, Tian W, Acheampong KN, Aftab MU, and Ahmad M
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- Humans, Accidents, Traffic, Attention, Pedestrians, Automobile Driving
- Abstract
In autonomous driving and Intelligent transportation systems, pedestrian detection is vital in reducing traffic accidents. However, detecting small-scale and occluded pedestrians is challenging due to the ineffective utilization of the low-feature content of small-scale objects. The main reasons behind this are the stochastic nature of weight initialization and the greedy nature of nonmaximum suppression. To overcome the aforesaid issues, this work proposes a multifocus feature extractor module by fusing feature maps extracted from the Gaussian and Xavier mapping function to enhance the effective receptive field. We also employ a focused attention feature selection on a higher layer feature map of the single shot detector (SSD) region proposal module to blend with its low-layer feature to tackle the vanishing of the feature detail due to convolution and pooling operation. In addition, this work proposes a decaying nonmaximum suppression function considering score and Intersection Over Union (IOU) parameters to tackle high miss rates caused by greedy nonmaximum suppression used by SSD. Extensive experiments have been conducted on the Caltech pedestrian dataset with the original annotations and the improved annotations. Experimental results demonstrate the effectiveness of the proposed method, particularly for small and occluded pedestrians., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Addis Abebe Assefa et al.)
- Published
- 2022
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214. Effects of short-term Huatou Chan training on health.
- Author
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Luo F, Qiang V, Wu Y, Wang Y, Tian W, Ma Z, and Mao Y
- Subjects
- Anger, Emotions, Humans, Surveys and Questionnaires, Anxiety prevention & control, Depression
- Abstract
Previous studies have shown that perennial Chan training leads to improvements in brain functioning. However, few studies have investigated the effects of short-term Huatou Chan training. The current study explored the effects of a three-day Huatou Chan training on physical and emotional health, as well as brain state. Seventy healthy subjects were recruited and divided into two groups: the Huatou Chan group and the Control group. The Huatou Chan group received a 3-day Huatou Chan training, while the Control group waited for three days. Both groups completed a 6 min Brain State Index recording, the SCL-90, the brief profile of mood state, the meaning in life questionnaire, and the Index of Well-being, prior to and after the training or waiting period. Results showed that short-term Huatou Chan training had significant benefits on some aspects such as physical and emotional health (obsessive-compulsive, depression, hostility, and psychoticism), negative emotions (tension-anxiety, depression-dejection, anger-hostility, fatigue-inertia, and confusion-bewilderment), well-being, and attitude towards life. In addition, short-term Chan training can significantly improve brain state, as shown by the index of depression, anxiety, alerting and intelligence. This is the first study to provide direct evidence for the benefits of short-term intensive Huatou Chan training on physical and mental health., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2022
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215. ApoC2 deficiency elicits severe hypertriglyceridemia and spontaneous atherosclerosis: A rodent model rescued from neonatal death.
- Author
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Gao M, Yang C, Wang X, Guo M, Yang L, Gao S, Zhang X, Ruan G, Li X, Tian W, Lu G, Dong X, Ma S, Li W, Wang Y, Zhu H, He J, Yang H, Liu G, and Xian X
- Subjects
- Animals, Animals, Newborn genetics, Apolipoprotein C-II therapeutic use, Blood Glucose, Cricetinae, Disease Models, Animal, Gene Knockout Techniques, Homeostasis, Humans, Hypertriglyceridemia drug therapy, Lipids, Mesocricetus, Apolipoprotein C-II deficiency, Atherosclerosis etiology, Hypertriglyceridemia etiology
- Abstract
Rationale: ApoC2 is an important activator for lipoprotein lipase-mediated hydrolysis of triglyceride-rich plasma lipoproteins. ApoC2-deficient patients display severe hypertriglyceridemia (sHTG) and recurrent acute pancreatitis. However, due to embryonic lethality in ApoC2 deleted mouse extensive understanding of ApoC2 function is limited in mammalian species., Objective: We sought to generate an animal model with ApoC2 deficiency in a rodent with some human-like features and then study the precise effects of ApoC2 on lipid and glucose homeostasis., Methods and Results: Using CRISPR/Cas9, we deleted Apoc2 gene from golden Syrian hamster and the homozygous (-/-) pups can be born in matured term but exhibited neonatal lethality. By continuous iv administration of normal hamster serum the ApoC2
-/- pups could survive till weaning and displayed severe HTG in adulthood on chow diet. A single iv injection of AAV-hApoC2 at birth can also rescue the neonatal death of ApoC2-/- pups. Adult ApoC2-/- hamsters exhibited a unique phenotype of sHTG with hypoglycemia, hypoinsulinemia and spontaneous atherosclerosis. The sHTG in ApoC2-/- adult hamsters could not be corrected by various lipid-lowering medications, but partially ameliorated by medium chain triglyceride diet and completely corrected by AAV-hApoC2., Conclusions: Our study provides a novel ApoC2-deleted mammalian model with severe hypertriglyceridemia that was fully characterized and highlights a potential therapeutic approach for the treatment of ApoC2 deficient patients., Competing Interests: Declaration of competing interest The authors have no conflict of interest to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)- Published
- 2020
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216. [Comparison of HBV persistent infection mice models by different serotypes of AAVs carrying HBV genomes].
- Author
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Zhu X, Zhou Q, Tian W, Liu C, Dong X, Wu X, and Yu C
- Subjects
- Animals, Disease Models, Animal, Enzyme-Linked Immunosorbent Assay, Genetic Vectors, Hepatitis B Core Antigens metabolism, Hepatitis B Surface Antigens blood, Hepatitis B e Antigens blood, Mice, Mice, Inbred C57BL, Serogroup, Virus Replication, Dependovirus classification, Genome, Viral, Hepatitis B virology, Hepatitis B virus genetics
- Abstract
In recent years, Hepatitis B virus (HBV) persistent infection mouse model with recombinant adeno-associated virus 8 carrying 1.3 copies of HBV genome (rAAV8-1.3HBV) is concerned. We studied and compared the efficacy among HBV persistent infection mice models by other serotypes except AAV8. First, we prepared and purified five viruses: rAAV1-1.3HBV, rAAV2-1.3HBV, rAAV5-1.3HBV, rAAV8-1.3HBV and rAAV9-1.3HBV. Then we injected each virus into 3 C57BL/6J mice with the dose of lx 1011 vg (Viral genome, vg) per mouse. We detected HBsAg and HBeAg in sera by enzyme-linked immunosorbent assay (ELISA) at different time points post injection. We killed mice 8 weeks post injection and took blood and livers for assay. We detected copies of HBV DNA by real-time quantitative PCR in sera and livers. Meantime, we detected HBcAg in the livers of mice by immunohistochemistry and further performed pathology analysis of these livers. The five groups of mice, HBeAg and HBsAg expression sustained 8 weeks in serological detection and HBV DNA was both detected in sera and livers at the time of 8 weeks post injection. HBeAg, HBsAg, HBV DNA copies expression levels in descending order were AAV8>AAV9>AAV1>AAV5>AAV2. HBcAg expression was detected in livers as well. Varied degrees of liver damage were shown in five groups of mice. This study provides more alternative AAV vector species to establish a persistent infection with hepatitis B model.
- Published
- 2015
217. Evaluation of miR-122-regulated suicide gene therapy for hepatocellular carcinoma in an orthotopic mouse model.
- Author
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Wang G, Dong X, Tian W, Lu Y, Hu J, Liu Y, Yuchi J, and Wu X
- Abstract
Objective: Intratumoral administration of adenoviral vector encoding herpes simplex virus (HSV) thymidine kinase (TK) gene (Ad-TK) followed by systemic ganciclovir (GCV) is an effective approach in treating experimental hepatocellular carcinoma (HCC). However, hepatotoxicity due to unwanted vector spread and suicide gene expression limited the application of this therapy. miR-122 is an abundant, liver-specific microRNA whose expression is decreased in human primary HCC and HCC-derived cell lines. These different expression profiles provide an opportunity to induce tumor-specific gene expression by miR-122 regulation., Methods: By inserting miR-122 target sequences (miR-122T) in the 3' untranslated region (UTR) of TK gene, we constructed adenovirus (Ad) vectors expressing miR-122-regulated TK (Ad-TK-122T) and report genes. After intratumoral administration of Ad vectors into an orthotopic miR-122-deficient HCC mouse model, we observed the miR-122-regulated transgene expression and assessed the antitumor activity and safety of Ad-TK-122T., Results: Insertion of miR-122T specifically down-regulated transgene expression in vitro and selectively protected the miR-122-positive cells from killing by TK/GCV treatment. Insertion of miR-122T led to significant reduction of tansgene expression in the liver without inhibition of its expression in tumors in vivo, resulting in an 11-fold improvement of tumor-specific transgene expression. Intratumoral injection of Ad vectors mediated TK/GCV system led to a vector dosage-dependent regression of tumor. The insertion of miR-122T does not influence the antitumor effects of suicide gene therapy. Whereas mice administrated with Ad-TK showed severe lethal hepatotoxicity at the effective therapeutic dose, no liver damage was found in Ad-TK-122T group., Conclusions: miR-122-regulated TK expression achieved effective anti-tumor effects and increased the safety of intratumoral delivery of adenovirus-mediated TK/GCV gene therapy for miR-122-deficient HCC.
- Published
- 2013
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218. [High activity level of miR-206 discovered in BHK21 cells by high-throughput miRNA activity profiling].
- Author
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Tian W, Dong X, Wang G, Zheng G, Zhou Q, Dong Z, and Wu X
- Subjects
- Animals, Cell Line, Chlorocebus aethiops, Cricetinae, Gene Expression Regulation, HEK293 Cells, Humans, Vero Cells, Connexin 43 metabolism, MicroRNAs genetics, Myosin Heavy Chains metabolism
- Abstract
Activities of 58 miRNAs for BHK21, HEK293, and Vero cell lines were screened using the high-throughput miRNA activity profiling method. miR-206 activity was found specifically high in BHK21. Considering miR-206 was recognized as a muscle-specific miRNA, we further detected the expression and activity level of miR-206 in BHK21 cells, with myoblast cells C2C12 as positive control and HEK293 cells as negative control. Then, we induced BHK21 by culturing with medium containing 2% horse serum (HS) and tested expression level of slow skeletal myosin heavy chain (MHC), activity and expression levels of miR-206, and expression level of Connexin43 (Cx43) which was reported negatively regulated by miR-206. Results demonstrated that activity and expression levels of miR-206 were both higher in BHK21 cells than in C2C12 cells. After induction of HS, MHC expression level was increased in BHK21 cells. The activity and expression levels of miR-206 were further enhanced. The Cx43 expression level was decreased. These results suggested that BHK21 had the characters of myoblast cells. In conclusion, we firstly discovered that miR-206 activity was specifically high in BHK21 cells, suggesting that BHK21 cells were derived from interstitial cells other than parenchyma cells of kidney from miRNA point of view. Our study also indicated that BHK21 cells were able to be used as models in vitro for research of miR-206 function.
- Published
- 2013
219. [Anti-HBV effect of nucleotide analogues on mouse model of chronic HBV infection mediated by recombinant adeno-associated virus 8].
- Author
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Wang G, Wang G, Dong X, Tian W, Yuchi J, Wei G, Meng H, and Wu X
- Subjects
- Animals, Dependovirus metabolism, Disease Models, Animal, Genetic Vectors, Genome, Viral, Guanine analogs & derivatives, Guanine pharmacology, Hepatitis B Antibodies blood, Hepatitis B virus genetics, Hepatitis B virus physiology, Lamivudine pharmacology, Mice, Mice, Inbred C57BL, Transduction, Genetic, Virus Replication, Antiviral Agents pharmacology, Dependovirus genetics, Hepatitis B, Chronic virology, Nucleotides pharmacology
- Abstract
We evaluated the anti-HBV effects of nucleotide analogues, Entecavir (ETV) and Lamivudine (LAM) targeting mouse model of HBV persistent infection with recombinant adeno-associated virus 8 carrying 1.3 copies of HBV genome (rAAV8-1.3HBV). Ninety percent (27 of 30 mice) of rAAVS-treated mice were chosen as mouse model. Four groups were orally administrated with different doses of ETV (1 mg/(kgd) or 0.1 mg/(kgd)) and LAM (500 mg/(kgd) or 100 mg/(kgd)) once a day for 10 days. The other two groups were set as normal saline treated and untreated control. We detected the levels of HBV DNA, HBeAg and HBsAg in sera at different time. Results indicate that HBV DNA level decreased significantly (P < 0.05) in drug-treated groups compared with normal saline group after drug administration. Fifteen days after the drug withdrawal, HBV DNA level rebounded back obviously (P < 0.05) in groups with low doses of ETV and LAM. However, there was no apparent change of HBeAg and HBsAg in the whole process among all groups. These results showed that our model could reflect the anti-viral effect of nucleotide analogues. This model can be a useful and convenient tool for anti-HBV drug discovery.
- Published
- 2013
220. High-throughput functional microRNA profiling using recombinant AAV-based microRNA sensor arrays.
- Author
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Tian W, Dong X, Wu X, and Wu Z
- Subjects
- Animals, Base Sequence, Cell Line, Cloning, Molecular, Cricetinae, Escherichia coli, Genetic Vectors, Oligonucleotide Array Sequence Analysis, Biosensing Techniques, Dependovirus genetics, High-Throughput Screening Assays, MicroRNAs chemistry
- Abstract
There is a lack of methods for high-throughput functional microRNA (miRNA) profiling. In this chapter, we describe a recombinant adeno-associated virus-based miRNA sensor array (miRNA Asensor array), which is able to profile functional miRNAs in cultured cells. The preparation of an miRNA Asensor array and its usage are discussed.
- Published
- 2013
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221. [Application of secretary luciferase labeled orthotopic transplant model of hepatocellular carcinoma to evaluate tumor response to interferon-beta gene therapy].
- Author
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Wang G, Lian Z, Tian W, Dong X, Yuchi J, and Wu X
- Subjects
- Animals, Carcinoma, Hepatocellular pathology, Cell Line, Tumor, Genes, Reporter, Genetic Therapy, Liver Neoplasms pathology, Luciferases blood, Luciferases metabolism, Mice, Mice, Inbred C57BL, Neoplasm Transplantation, Treatment Outcome, Carcinoma, Hepatocellular therapy, Interferon-beta genetics, Interferon-beta therapeutic use, Liver Neoplasms therapy, Luciferases genetics
- Abstract
To establish an orthotopic transplant mouse model of hepatocellular carcinoma (HCC) labeled with secretary luciferase and to study its response to anti-tumor treatment with interferon-beta gene therapy. We labeled the murine hepatoma Hepal-6 cells with secretary Gaussia princeps luciferase (Gluc), and then injected Gluc labeled Hepal-6 cells intrasplenically in C57BL/6 mice. We monitored blood Glue to evaluate the tumor development and anti-tumor effects of hydrodynamic injection with interferon-beta expressing plasmid. We successfully established the orthotopic mouse model of HCC by intrasplenic injection of Glue labeled Hepal-6 cells. The Glue blood assay could reflect the amount of cancer cells in vivo, tumor progression, as well as anti-tumor effect of interferon-beta gene therapy. In conclusion, Gluc labeled orthotopic transplant mouse model of HCC can ex vivo real-time monitor the tumor development and tumor response to treatments.
- Published
- 2012
222. [A novel method for monitoring miRNA activity by expression changes of secreted luciferase gene in live cells].
- Author
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Tian W, Dong X, Wang G, and Wu X
- Subjects
- Genes, Reporter genetics, Genetic Vectors, HEK293 Cells, Humans, K562 Cells, Luciferases genetics, U937 Cells, Luciferases biosynthesis, MicroRNAs metabolism, Transfection
- Abstract
We developed a method for monitoring of miRNA activity in live cells by a secreted luciferase gene based plasmid sensor named as Gsensor. Firstly, we constructed pAAV2neo-Gluc-MCS-polyA as "empty Gsensor", which contained multiple cloning sites (MCS) for miRNA target inserted. To detect miR142-3p activity, miR142-3p Gsensor and miR142-3p Gsensor-3 were constructed by inserting one or three complementary miR142-3p targets into pAAV2neo-Gluc-MCS-ployA. Subsequently, miR142-3p Gsensor and miR142-3p Gsensor-3 were respectively transfected into U937 cells and Gluc activity was assayed in the supernatant 48 h post transfection. Results showed that both of them effectively indicated miR142-3p activity of inhibiting Gluc expression compared with empty Gsensor. Simultaneously, miR142-3p Gsensor also demonstrated the inhibition of miR142-3p activity by Anti-miR142 when they were cotransfected into U937 cells. This implied one copy of miRNA target in Gsensor was sensitive enough for investigation of miRNA activity. We further analyzed factors affecting Gsensor function including time and dose, and found that miR142-3p activity sensed by miR142-3p Gsensor rose within 48 h post transfection and approached stable thereafter. Transfected dose varying among 0.001-0.05 pg/cell had little effect on its function. Using miR142-3p Gsensor, we further detected miR142-3p activity in HEK293, U937, K562, SP2/0 and P815 cells. Results suggested that miR142-3p activity was high in U937, K562, SP2/0 and P815 cells and almost negative in HEK293. miR142-3p activity was positively correlated with its relative copies in HEK293, U937 and K562 detected by QRT-PCR. In conclusion, Gsensor proved to be an effective tool for monitoring of miRNA activity in live cells, and provide a new method for monitoring miRNA activity in vitro.
- Published
- 2010
223. [A novel packaging system of recombinant AAV5/5 vector].
- Author
-
Dong X, Tian W, Yuan Z, Tan S, and Wu X
- Subjects
- Dependovirus physiology, Genetic Therapy, HEK293 Cells, Herpesvirus 1, Human physiology, Humans, Reassortant Viruses genetics, Recombination, Genetic, Viral Proteins genetics, Dependovirus genetics, Genetic Vectors, Herpesvirus 1, Human genetics, Virus Assembly
- Abstract
We developed a scalable AAV5/5 vector packaging system by using replication competent recombinant herpes simplex type 1 virus as helper virus. The fragment containing rep and cap genes of AAV5 was inserted into the non-necessary gene (UL2) of HSV1 genome, resulting in the helper virus rHSV1-rep5cap5. An AAV5/5 vector pAAV5neo carrying two AAV5 ITRs was constructed by inserting a neo gene expression cassette into the plasmid backbone of pAV5CMV-GFP. pAAV5neo-EGFP was constructed by inserting EGFP gene into pAAV5neo. BHK21 cell was transfected with pAAV5neo-EGFP and cultured in the presence of G418. EGFP expression positive monoclonal cells were picked up, and one that produced rAAV5/5-EGFP with the highest efficiency under the help of rHSV1-rep5cap5 was chosen as the production cell line named as C020. rAAV5/5-EGFP was produced by infecting C020 cells with rHSV1-rep5cap5, and crudely purified by our previous method of 'chloroform treatment-PEG8000/NaCl precipitation- chloroform extract'. rAAV5/5-EGFP preparation with high purity was obtained by ultrafiltration with molecular weight cut-off value of 100 kDa. SDS-PAGE stained with Coomassie brilliant blue R250 showed clearly specific pattern of three bands of AAV capsid proteins. rAAV5/5-EGFP was also assayed using negative stain transmission electron microscopy and the majority of the virus particles were found solid. About 30% green fluorescent cells could be seen after infecting HEK293 cells with rAAV5/5-EGFP 24 h at 1 x 10(5) vg/cell. In conclusion, we have established an efficient AAV5/5 vector production system and could produce recombinant AAV5/5 virus in large amounts for gene therapy research.
- Published
- 2010
224. [Real time ex vivo detection and dynamic monitoring of in vivo expression of secreted luciferase gene injected by hydrodynamic method].
- Author
-
Tian W, Wang G, Luo S, Dong X, Fu X, Tan W, and Wu X
- Subjects
- Animals, Genes, Reporter genetics, Genetic Therapy, Hep G2 Cells, Humans, Hydrodynamics, Injections, Intravenous, Liver metabolism, Luciferases administration & dosage, Luciferases biosynthesis, Male, Mice, Mice, Inbred BALB C, Gene Expression Regulation, Luciferases genetics, Luciferases pharmacokinetics, Transfection
- Abstract
We chose Gaussia luciferase (Gluc), a secreted luciferase gene as reporter to real-time detect and dynamically monitor hydrodynamic injection gene expression. First, we constructed an expression vector pAAV2neo-Gluc. Then Huh7 and HepG2 cells were transfected with pAAV2neo-Gluc and the activity of Gluc in the supernatant and cell lysates were assayed. Results showed that the Gluc activity in the supernatant was about 100 higher than that in cell lysates, indicating the expressed Gluc existing mainly as a secreted form as reported. Live bioluminescence imaging of mice hydrodynamic injected pAAV2neo-Gluc showed whole body distribution, while the pAAV2neo-Fluc primarily located in the liver. Then we injected different doses of pAAV2neo-Gluc into mice by tail-vein hydrodynamic injection, took minor amount of blood from mice tails at different time points and measured the luciferase activity to investigate dynamic changes of Gluc expression and secretion in vivo. The results suggested that the time courses of Gluc expression were highly consistent among each dose groups. The luciferase activity in blood could be detected as early as 2 h after injection, reached the peak at about 10 h and gradually decreased from then on. The expression level of Glue was positively correlated with the dose of injected plasmid DNA. To further detect the assay sensitivity of the ex vivo Gluc measurement method, we investigated three additional groups of mice injected with lower doses of 0.001 microg, 0.01 microg and 0.1 microg pAAV2neo-Gluc respectively. Results revealed that activity of Gluc in blood could be detected even at dose as low as 0.001 microg DNA, suggesting the assay sensitivity was extremely high. In conclusion, a real-time ex vivo detection method of dynamically monitoring of gene expression in vivo by hydrodynamic injection can be a valuable means for the study of gene expression regulation in vivo.
- Published
- 2009
225. Pairwise alignment of interaction networks by fast identification of maximal conserved patterns.
- Author
-
Tian W and Samatova NF
- Subjects
- Animals, Biometry, Databases, Protein, Pattern Recognition, Automated, Protein Interaction Domains and Motifs genetics, Proteins chemistry, Proteins genetics, Sequence Alignment statistics & numerical data, Systems Biology, Algorithms, Protein Interaction Mapping statistics & numerical data
- Abstract
A number of tools for the alignment of protein-protein interaction (PPI) networks have laid the foundation for PPI network analysis. They typically find conserved interaction patterns by various local or global search algorithms, and then validate the results using genome annotation. The improvement of the speed, scalability and accuracy of network alignment is still the target of ongoing research. In view of this, we introduce a connected-components based algorithm, called HopeMap for pairwise network alignment with the focus on fast identification of maximal conserved patterns across species. Observing that the number of true homologs across species is relatively small compared to the total number of proteins in all species, we start with highly homologous groups across species, find maximal conserved interaction patterns globally with a generic scoring system, and validate the results across multiple known functional annotations. The results are evaluated in terms of statistical enrichment of gene ontology (GO) terms and KEGG ortholog groups (KO) within conserved interaction patters. HopeMap is fast, with linear computational cost, accurate in terms of KO groups and GO terms specificity and sensitivity, and extensible to multiple network alignment.
- Published
- 2009
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