Systematic Review on Epstein-Barr Virus (EBV) DNA in Diagnosis of Nasopharyngeal Carcinoma in Asian Populations

Han, Bao-Lin,Xu, Xiang-Ying,Zhang, Chun-Zhi,Wu, Jian-Juan,Han, Chun-Feng,Wang, Hui,Wang, Xuan,Wang, Guang-Shun,Yang, Shu-Juan,Xie, Yao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Objective: To conduct a meta-analysis to investigate the value of EBV DNA in diagnosis of nasopharyngeal cancer (NPC) in Asian populations, and provide important evidence for screening. Methods: Prospective or respective case-control or cohort studies regarding the detection role of EBV DNA for NPC were included in our study. We conducted a comprehensive literature search in PubMed, EMBASE, and the Chinese Biomedical Database (CBM database between January 1980 and March 2012. Results: A total of 18 studies with 1492 NPC cases and 2641 health controls were included. Almost of the included studies were conducted in China, and only one other conducted in Thailand. The overall results demonstrated that the pooled sensitivity, specificity, positive likelihood (+LR) and negative likelihood (-LR) were 0.73 (0.71-0.75), 0.89 (0.88-0.90), 8.84 (5.65-13.84) and 0.19(0.11-0.32), respectively. The overall EBV DNA detection showed the largest area of 0.932 under the summary receiver operator curve (SROC). The accuracy of detection by plasma for NPC (0.86) was higher than in serum (0.81), with largest areas under the SROC of 0.97 and 0.91, respectively. Conclusion: Our results demonstrated the EBV DNA detection in plasma or serum has high sensitivity and specificity in diagnosis of NPC, especially in Chinese populations with a high risk of cancer.

Design and Implementation of a Robust Predictive Control Scheme for Active Power Filters

Han, Yang,Xu, Lin The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.5

This paper presents an effective robust predictive control scheme for the active power filter (APF) using a smith-predictor based current regulator, which show superior features when compared to proportional-integral (PI) controllers in terms of an enhanced closed-loop bandwidth and an improved current tracking accuracy. A moving average filter (MAF) is implemented using a field programmable gate array (FPGA) for signal pre-processing to eliminate the switching ripple contamination. An adaptive linear neural network (ADALINE) is used for individual harmonic estimation to achieve selective compensation purpose. The effectiveness and validity of the devised control algorithm are confirmed by extensive simulation and experimental results.

Influences of friction and mesh misalignment on time-varying mesh stiffness of helical gears

Lin Han,Lixin Xu,Houjun Qi 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.7

As one of the most important excitation sources of vibration, time-varying mesh stiffness of helical gear pairs need accurately calculated. Compared with spur gears, friction in helical gears is significant. This work for the first time presents an improved calculation method for the mesh stiffness of helical gears with effect of friction incorporated. Firstly, helical gear is sliced into number of pieces along its axis direction and each piece could be regarded as spur gear. Then forces applied to each piece including friction force are analyzed. Potential energy method is employed to develop time-varying mesh stiffness of each piece pair of both kinds of helical gears with different transverse and axial contact ratios. Furthermore, influences of various working conditions and misalignment on mesh stiffness are also investigated. Results indicate that effect brought by friction on total mesh stiffness should be not neglected. The reduction amount of stiffness increases with lower speed, heavier load and rougher surface. The stiffness difference between cases with and without friction is affected by gear geometry and mounting parameters like module, helix angle and mounting misalignment. This work provides an essential tool for comprehensive dynamics analysis with consideration of the relationship between stiffness and working conditions.

Effects of exogenous putrescine on the ultrastructure of and calcium ion flow rate in lettuce leaf epidermal cells under drought stress

Xu Zhu,Lin Wang,Yingyan Han,Chaojie Liu,Shuangxi Fan 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.4

The alleviation eff ects of exogenous putrescine treatment on the ultrastructure of and calcium ion fl ow rate in lettuce ( Lactucasativa L.) leaf cells under drought stress were studied. Lettuce seedlings were treated with foliar sprays of 0.1 mM putrescinefor 8 days, after which drought stress was simulated by using 10% polyethylene glycol 6000. The morphological characteristicsof the seedlings and the calcium ion fl ow rate across stomatal guard cells were subsequently determined, and the leaf cellultrastructure was observed via transmission electron microscopy. Under drought stress, the morphological characteristics of the seedlings decreased, and calcium ion infl ux was predominant in the guard cells. In addition, compared to that under control conditions, the stomatal density under drought stress conditions increased signifi cantly, the open/closed stoma ratio was lower, and the degree of stomatal opening was smaller. Exogenous putrescine sprays eff ectively reduced the stomatal density, increased the degree of stomatal opening, and increased the proportion of open stomata. In addition, the chloroplasts became round in shape, the thylakoid structure became blurry in appearance, the number of starch grains decreased, many osmium granules were produced, and plasmolysis occurred in the mesophyll cells. However, the chloroplasts were elongated, the thylakoid structure was clear, the starch grains were abundant, few osmium granules were produced, and plasmolysis did not occur. The above results show that, by altering the leaf cell ultrastructure as well as the fl ow rate and direction of calcium ions in guard cells, exogenous putrescine eff ectively improves the drought tolerance of lettuce.

Deep Multi-Agent Reinforcement Learning for Resource Allocation in D2D Communication Underlaying Cellular Networks

Xu Zhang,Ziqi Lin,Beichen Ding,Bo Gu,Yu Han 한국통신학회 2020 한국통신학회 APNOMS Vol.2020 No.09

Device-to-device communications underlaying cellular networks have been recognized as one of the key technologies for the fifth generation (5G) cellular system to improve the spectrum efficiency and system capacity. In this paper, we investigate the potential of deep reinforcement learning (DRL) for joint subcarrier assignment and power allocation in a general form of D2D networks, where a subcarrier can be assigned to multiple D2D pairs and each D2D pair is permitted to utilize multiple subcarriers. We first formulate the above problem as a Markov decision process, and then propose a double deep Q-network (DQN)-based subcarrier-power allocation algorithm to learn the optimal policy in the absence of full instantaneous channel state information (CSI). Specifically, each D2D pair acts as a learning agent that adjusts its own subcarrier-power allocation strategy iteratively through interactions with the operating environment in a trial-and-error fashion. Simulation results confirm that the proposed algorithm achieves near optimal performance in real time. It is worth mentioning that the proposed algorithm is especially suitable for the case where the environmental dynamics is not accurate and the CSI delay cannot be ignored.

Metabolic reprogramming and epigenetic modifications in cancer: from the impacts and mechanisms to the treatment potential

Xu Xuemeng,Peng Qiu,Jiang Xianjie,Tan Shiming,Yang Yiqing,Yang Wenjuan,Han Yaqian,Chen Yuyu,Oyang Linda,Lin Jinguan,Xia Longzheng,Peng Mingjing,Wu Nayiyuan,Tang Yanyan,Li Jinyun,Liao Qianjin,Zhou Yuju 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Metabolic reprogramming and epigenetic modifications are hallmarks of cancer cells. In cancer cells, metabolic pathway activity varies during tumorigenesis and cancer progression, indicating regulated metabolic plasticity. Metabolic changes are often closely related to epigenetic changes, such as alterations in the expression or activity of epigenetically modified enzymes, which may exert a direct or an indirect influence on cellular metabolism. Therefore, exploring the mechanisms underlying epigenetic modifications regulating the reprogramming of tumor cell metabolism is important for further understanding tumor pathogenesis. Here, we mainly focus on the latest studies on epigenetic modifications related to cancer cell metabolism regulations, including changes in glucose, lipid and amino acid metabolism in the cancer context, and then emphasize the mechanisms related to tumor cell epigenetic modifications. Specifically, we discuss the role played by DNA methylation, chromatin remodeling, noncoding RNAs and histone lactylation in tumor growth and progression. Finally, we summarize the prospects of potential cancer therapeutic strategies based on metabolic reprogramming and epigenetic changes in tumor cells.

Alum sludge conditioning with ferrous iron/peroxymonosulfate oxidation: Characterization and mechanism

Xu Zhou,Wenbiao Jin,Lan Wang,Lin Che,Chuan Chen,Shao-feng Li,Xue-Ting Wang,Renjie Tu,Song-fang Han,Xiaochi Feng,Nan-Qi Ren 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.4

Alum sludge produced by drinking water plants needs to be conditioned and dewatered before final disposal. In this study, a novel ferrous iron/peroxymonosulfate (PMS) oxidation process was employed to enhance alum sludge dewaterability. The effect of oxidative sulfate radicals generated by Fe2+ activated HSO5  on alum sludge was studied. The results showed that the optimal conditioning conditions for addition of Fe2+ and PMS were 0.5 g/g and 0.1 g/g TSS, respectively. Meanwhile, the capillary suction time (CST) and specific resistance to filtration (SRF) of alum sludge was reduced by 66% and 88%. Also found was that the absolute value of the zeta potential increased and the particle size decreased in alum sludge after Fe2+-PMS conditioning, which indicated that oxidative sulfate radicals destroyed the floc structure of alum sludge and smaller particles were generated. At the same time, the water contained in sludge flocs was released and enhanced sludge dewaterability, while leaching of aluminum ions also characterized decomposition of alum sludge.

Sequence Pulse Modulation for Voltage Balance in a Cascaded H-Bridge Rectifier

Xu Peng,Xiaoqiong He,Pengcheng Han,Xiaolan Lin,Zeliang Shu,Shibin Gao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.3

With the development of multilevel converters, cascaded single-phase H-bridge rectifiers (CHBRs) has become widely adopted in high-voltage high-power applications. In this study, sequence pulse modulation (SPM) is proposed for CHBRs. SPM is designed to balance the dc-link voltage and maintain the smooth changes of switch states. In contrast to phase disposition modulation, SPM balances the dc-link voltage even after removing the load of one submodule. The operation principle of SPM is deduced, and the unbalance degree of SPM is analyzed. All the proposed approaches are experimentally verified through a prototype of a four-module (nine-level) CHBR. Conclusions are drawn in accordance with the results of SPM and its imbalance degree analysis.

Identification of mountain-cultivated ginseng and cultivated ginseng using UPLC/oa-TOF MSE with a multivariate statistical sample-profiling strategy

Xu, Xin-fang,Cheng, Xian-long,Lin, Qing-hua,Li, Sha-sha,Jia, Zhe,Han, Ting,Lin, Rui-chao,Wang, Dan,Wei, Feng,Li, Xiang-ri The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.4

Background: Mountain-cultivated ginseng (MCG) and cultivated ginseng (CG) both belong to Panax ginseng and have similar ingredients. However, their pharmacological activities are different due to their significantly different growth environments. Methods: An ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS)-based approach was developed to distinguish MCG and CG. Multivariate statistical methods, such as principal component analysis and supervised orthogonal partial-least-squares discrimination analysis were used to select the influential components. Results: Under optimized UPLC-QTOF-MS/MS conditions, 40 ginsenosides in both MCG and CG were unambiguously identified and tentatively assigned. The results showed that the characteristic components of CG and MCG included ginsenoside Ra3/isomer, gypenoside XVII, quinquenoside R1, ginsenoside Ra7, notoginsenoside Fe, ginsenoside Ra2, ginsenoside Rs6/Rs7, malonyl ginsenoside Rc, malonyl ginsenoside Rb1, malonyl ginsenoside Rb2, palmitoleic acid, and ethyl linoleate. The malony ginsenosides are abundant in CG, but higher levels of the minor ginsenosides were detected in MCG. Conclusion: This is the first time that the differences between CG and MCG have been observed systematically at the chemical level. Our results suggested that using the identified characteristic components as chemical markers to identify different ginseng products is effective and viable.

Design and Implementation of a Robust Predictive Control Scheme for Active Power Filters

Yang Han,Lin Xu 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.5

This paper presents an effective robust predictive control scheme for the active power filter (APF) using a smith-predictor based current regulator, which show superior features when compared to proportional-integral (PI) controllers in terms of an enhanced closed-loop bandwidth and an improved current tracking accuracy. A moving average filter (MAF) is implemented using a field programmable gate array (FPGA) for signal pre-processing to eliminate the switching ripple contamination. An adaptive linear neural network (ADALINE) is used for individual harmonic estimation to achieve selective compensation purpose. The effectiveness and validity of the devised control algorithm are confirmed by extensive simulation and experimental results.