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      • MTHFR Polymorphisms and Pancreatic Cancer Risk:Lack of Evidence from a Meta-analysis

        Li, Lei,Wu, Sheng-Di,Wang, Ji-Yao,Shen, Xi-Zhong,Jiang, Wei Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

        Objective: Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms have been reported to be associated with pancreatic cancer, but the published studies had yielded inconsistent results.We therefore performed the present meta-analysis. Methods: A search of Google scholar, PubMed, Cochrane Library and CNKI databases before April 2012 was conducted to summarize associations of MTHFR polymorphisms with pancreatic cancer risk. Assessment was with odds ratios (ORs) and 95% confidence intervals (CIs). Publication bias were also calculated. Results: Four relative studies on MTHFR gene polymorphisms (C667T and A1298C) were involved in this meta-analysis. Overall, C667T(TT vs. CC : OR = 1.61, 95%CI = 0.78 - 3.34; TT vs. CT : OR = 1.41, 95%CI = 0.88-2.25; dominant model: OR = 0.68, 95%CI = 0.40-1.17; recessive model: OR = 0.82, 95%CI = 0.52-1.30) and A1298C(CC vs. AA:OR=1.01, 95%CI=0.47-2.17; CC vs. AC: OR=0.99,95%CI=0.46-2.14; dominant model: OR=1.01, 95%CI = 0.47-2.20; recessive model: OR = 1.01, 95%CI = 0.80-1.26) did not increase pancreatic cancer risk. Conclusion: This meta-analysis indicated that MTHFR polymorphisms (C667T and A1298C) were not associated with pancreatic cancer risk.

      • SCISCIESCOPUS

        Annular folded electrowetting liquid lens

        Li, Lei,Liu, Chao,Ren, Hongwen,Deng, Huan,Wang, Qiong-Hua The Optical Society 2015 Optics letters Vol.40 No.9

        <P>We report an annular folded electrowetting liquid lens. The front surface of the lens is coated with a circular reflection film, while the back surface of the lens is coated with a ring-shaped reflection film. This approach allows the lens to get optical power from the liquid-liquid interface three times so that the optical power is tripled. An analysis of the properties of the annular folded electrowetting liquid lens is presented along with the design, fabrication, and testing of a prototype. Our results show that the optical power of the proposed liquid lens can be enhanced from 20.1 to 50.2??m(-1) in comparison with that of the conventional liquid lens (aperture 3.9??mm). It can reduce the operating voltage by 10??V to reach the same diopter as a conventional liquid lens. Our liquid lens has the advantages of compact structure, light weight, and improved optical resolution.</P>

      • SCIESCOPUS

        Study on the micro-scale simulation of wind field over complex terrain by RAMS/FLUENT modeling system

        Li, Lei,Zhang, Li-Jie,Zhang, Ning,Hu, Fei,Jiang, Yin,Xuan, Chun-Yi,Jiang, Wei-Mei Techno-Press 2010 Wind and Structures, An International Journal (WAS Vol.13 No.6

        A meteorological model, RAMS, and a commercial computational fluid dynamics (CFD) model, FLUENT are combined as a one-way off-line nested modeling system, namely, RAMS/FLUENT system. The system is experimentally applied in the wind simulation over a complex terrain, with which numerical simulations of wind field over Foyeding weather station located in the northwest mountainous area of Beijing metropolis are performed. The results show that the method of combining a meteorological model and a CFD model as a modeling system is reasonable. In RAMS/FLUENT system, more realistic boundary conditions are provided for FLUENT rather than idealized vertical wind profiles, and the finite volume method (FVM) of FLUENT ensures the capability of the modeling system on describing complex terrain in the simulation. Thus, RAMS/FLUENT can provide fine-scale realistic wind data over complex terrains.

      • Chronic Hepatitis B Virus Infection and Risk of Pancreatic Cancer: A Meta-analysis

        Li, Lei,Wu, Bo,Yang, Li-Bo,Yin, Guan-Cheng,Liu, Ji-Yong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

        Objectives: A number of studies have shown that chronic hepatitis B virus infection is implicated in susceptibility to pancreatic cancer. However, the results are still controversial. This meta-analysis aimed to quantitatively assess the relationship between chronic hepatitis B virus infection and incidence of pancreatic cancer of cohort and case-control studies. Methods: A literature search was performed for entries from 1990 to 2012 using PUBMED and EMBASE. Studies were included if they reported odds ratios (ORs) and corresponding 95% CIs of pancreatic cancer with respect to the infection of hepatitis B virus. Results: Eight studies met the inclusion criteria, which included five case-control studies and three cohort studies. Compared with individuals who have not infection of hepatitis B virus, the pooled OR of pancreatic cancer was 1.403 (95%CI: 1.139-1.729, P=0.001) for patients with hepatitis B virus infection. Sub-group analysis by study design showed that the summary OR was 1.43 (95%CI: 1.06-1.94, P=0.021) when pooling case-control studies and 1.31 (95%CI: 1.00-1.72, P=0.05) when pooling cohort studies. Conclusion: Findings from this meta-analysis suggest that chronic hepatitis B virus infection may increase the risk of pancreatic cancer. This relationship needs to be confirmed by further follow-up studies.

      • KCI등재

        Finite-time Bipartite Synchronization of Complex-valued Complex Networks with Time Delay

        Li Lei,Degang Yang,Tao Liang,Wanli Zhang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.6

        Based on the framework of signed graphs, we investigate finite-time bipartite synchronization (FTBS) of delayed complex-valued complex networks (DCVCN) in this paper. Several control strategies with quantizer are designed, which can save communication resources. 1-norm analytical techniques are used and developed to present strict proof of theoretical results. Some FTBS criteria are established by use of multiple Lyapunov functions, and the settling time is estimated by means of control parameters and initial values. Numerical simulation results are given to verify the validity of theoretical analysis.

      • KCI등재

        Image Classification Algorithm Based on Proposal Region Clustering Learning-Unsupervised Deep Learning

        Li Lei,Yin Xiao-li 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.2

        Although deep learning has achieved certain results in image classification, images are susceptible to factors such as lighting conditions, shooting angles, complex backgrounds, rotation transformations or scale scaling, and image data sets in some areas are difficult to obtain. They make the deep learning framework unable to give full play to its generalization ability and nonlinear modeling ability in image classification. Therefore, this paper first proposes a proposal region clustering learning algorithm, which clusters the proposal regions in each image so that each cluster corresponds to the category of the image. Then, different clusters can be regarded as different multi-instance learning packets, and each packet uses the multi-instance learning method to learn the unsupervised image classification detector. It can effectively improve the generalization and modeling capabilities of deep learning models. In addition, this paper proposes an unsupervised deep learning method, which designs an unsupervised deep learning network structure and loss function according to the characteristics of the classified image, and combines densely connected blocks to extract features from the source image. It retains the multi-scale features of the middle layer of the classified image, and effectively solves the problem of insufficient image feature extraction information caused by the lack of image data. It also guarantees the accuracy of subsequent image classification. The experimental results show that the image classification method proposed in this paper not only solves the problem of insufficient image data sets and the interference of various complex factors, but also can accurately classify various image data sets. The accuracy of the image classification method proposed in this paper is 1.38–19% higher than other mainstream deep learning methods.

      • Comparison of Pre-Operation Diagnosis of Thyroid Cancer with Fine Needle Aspiration and Core-needle Biopsy: a Meta-analysis

        Li, Lei,Chen, Bao-Ding,Zhu, Hai-Feng,Wu, Shu,Wei, Da,Zhang, Jian-Quan,Yu, Li Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

        Background: The aim of this meta-analysis was to compare sensitivities and specificities of fine needle aspiration (FNA) and core needle biopsy (CNB) in the diagnosis of thyroid cancer. Materials and Methods: Articles were screened in Medline, the Cochrane Library, EMBASE and Google Scholar, and subsequently included and excluded based on the patient/problem-intervention-comparison-outcome (PICO) principle. Primary outcome was defined in terms of diagnostic values (sensitivity and specificity) of FNA and CNB for thyroid cancer. Secondary outcome was defined as the accuracy of diagnosis. Compiled FNA and CNB results from the final studies selected as appropriate for meta-analysis were compared with cases for which final pathology diagnoses were available. Statistical analyses were performed for FNA and CNB for all of the selected studies together, and for individual studies using the leave-one-out approach. Results: Article selection and screening yielded five studies for meta-analysis, two of which were prospective and the other three retrospective, for a total of 1,264 patients. Pooled diagnostic sensitivities of FNA and CNB methods were 0.68 and 0.83, respectively, with specificities of 0.93 and 0.94. The areas under the summary ROC curves were 0.905 (${\pm}0.030$) for FNA and 0.745 (${\pm}0.095$) for CNB, with no significant difference between the two. No one study had greater influence than any other on the pooled estimates for diagnostic sensitivity and specificity. Conclusions: FNA and CNB do not differ significantly in sensitivity and specificity for diagnosis of thyroid cancer.

      • SCIEKCI등재

        Influences of Solution pH and Redox Potential on the Bioleaching of $LiCoO_2$ from Spent Lithium-ion Batteries

        Li, Lei,Zeng, Gui-Sheng,Luo, Sheng-Lian,Deng, Xiao-Rong,Xie, Qing-Ji 한국응용생명화학회 2013 Applied Biological Chemistry (Appl Biol Chem) Vol.56 No.2

        The influences of solution pH and redox potential on bioleaching of $LiCoO_2$ from spent lithium-ion batteries using Acidithiobacillus ferrooxidans were investigated. Bioleaching at different initial pH and ferrous ion ($Fe^{2+}$) concentrations were carried out, and electrochemical behavior of $LiCoO_2$ dissolution was examined to study the effect of solution redox potential on the bioleaching process. The results showed maximum cobalt dissolution at initial pH of 1.5 and initial $Fe^{2+}$ concentration of 35 g/L, and cobalt dissolution showed only slight relationship with pH of solution. Nonetheless, there was improvement of cobalt dissolution at higher redox potential. The cyclic voltammograms showed that dissolution rates increase when the solution potentials are higher than 0.4 V, and rapid decrease at 1.3 V. The anodic polarization curves indicated that the corrosion, primary passive, and passivation potentials were 0.420, 0.776 and 0.802 V, respectively.

      • SCIESCOPUSKCI등재

        A Multi-Dimensional Radio Resource Scheduling Scheme for MIMO-OFDM Wireless Systems

        Li, Lei,Niu, Zhisheng The Korea Institute of Information and Commucation 2006 Journal of communications and networks Vol.8 No.4

        Orthogonal frequency division multiplexing (OFDM) and multiple input multiple output (MIMO) technologies provide additional dimensions of freedom with spectral and spatial resources for radio resource management. Multi-dimensional radio resource management has recently been identified to exploit the full dimensions of freedom for more flexible and efficient utilization of scarce radio spectrum while provide diverse quality of service (QoS) guarantees. In this work, a multi-dimensional radio resource scheduling scheme is proposed to achieve above goals in hybrid orthogonal frequency division multiple access (OFDMA) and space division multiple access (SDMA) systems. Cochannel interference (CCI) introduced by frequency reuse under SDMA is eliminated by frequency division and time division between highly interfered users. This scheme maximizes system throughput subjected to the minimum data rate guarantee. for heterogeneous users and transmit power constraint. By numerical examples, system throughput and fairness superiority of the our scheduling scheme are verified.

      • SCOPUSKCI등재

        Numerical Simulation and Experimental Research of the Flow Coefficient of the Nozzle-Flapper Valve Considering Cavitation

        Li, Lei,Li, Changchun,Zhang, Hengxuan Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.2

        The nozzle-flapper valves are widely applied as a pilot stage in aerospace and military system. A subject of the analysis presented in this work is to find out a reasonable range of null clearance between the nozzle and flapper. This paper has presented a numerical flow coefficient simulation. In every design point, a parameterized model is created for flow coefficient simulation and cavitation under different conditions with varying gap width and inlet pressure. Moreover, a new test device has been designed to measure the flow coefficient and for visualized cavitation. The numerical simulation and test results both indicate that cavitation intensity gets fierce initially and shrinks finally as the gap width varies from small to large. From the curve, the flow coefficient mostly has experienced three stages: linear throttle section, transition section and saturation section. The appropriate deflection of flapper is recommended to make the gap width drop into the linear throttle section. The flapper-nozzle null clearance is optionally recommended near the range of $D_N/16$. Finally through simulation it is also concluded that the inlet pressure plays a little role in the influence on the flow coefficient.

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