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| 1 | Level of circulating PD-L1 expression in patients with advanced gastric cancer and its clinical implications显示文摘Objective:The programmed cell death-1 receptor/programmed cell death-1 ligand(PD-1/PD-L1) pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.Methods:Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study.Circulating PD-L1 expression was tested by enzymelinked immunosorbent assay(ELISA).The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.Results:Expression of PD-L1 in advanced gastric cancer patients was significantly up-regulated compared with health people(P=0.006).The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis(P=0.026 and P=0.041,respectively).Although we didn't find significant difference in all advanced gastric cancer patients with different PD-L1 expression,the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients(65.6% vs.44.7%,P=0.028).Conclusions:PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis. | Zhixue Zheng Zhaode Bu Xijuan Liu Lianhai Zhang Ziyu Li Aiwen Wu Xiaojiang Wu Xiaojing Cheng Xiaofang Xing Hong Du Xiaohong Wang Ying Hu Jiafu Ji | 2014 | Chinese Journal of Cancer Research2014,26,1: | 37 |
| 2 | Exercise-induced irisin in bone and systemic irisin administration reveal new regulatory mechanisms of bone metabolism显示文摘Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domaincontaining 5(FNDC5) protein. Once released to circulation upon exercise or cold exposure, irisin stimulates browning of white adipose tissue(WAT) and uncoupling protein 1(UCP1) expression, leading to an increase in total body energy expenditure by augmented UCP1-mediated thermogenesis. It is currently unknown whether irisin is secreted by bone upon exercise or whether it regulates bone metabolism in vivo. In this study, we found that 2 weeks of voluntary wheel-running exercise induced high levels of FNDC5 messenger RNA as well as FNDC5/irisin protein expression in murine bone tissues. Increased immunoreactivity due to exercise-induced FNDC5/irisin expression was detected in different regions of exercised femoral bones,including growth plate, trabecular bone, cortical bone, articular cartilage, and bone–tendon interface. Exercise also increased expression of osteogenic markers in bone and that of UCP1 in WAT, and led to bodyweight loss. Irisin intraperitoneal(IP) administration resulted in increased trabecular and cortical bone thickness and osteoblasts numbers, and concurrently induced UCP1 expression in subcutaneous WAT. Lentiviral FNDC5 IP administration increased cortical bone thickness. In vitro studies in bone cells revealed irisin increases osteoblastogenesis and mineralization, and inhibits receptor activator of nuclear factor-k B ligand(RANKL)-induced osteoclastogenesis. Taken together, our findings show that voluntary exercise increases irisin production in bone, and that an increase in circulating irisin levels enhances osteogenesis in mice. | Jin Zhang Paloma Valverde Xiaofang Zhu Dana Murray Yuwei Wu Liming Yu Hua Jiang Michel M Dard Jin Huang Zhiwei Xu Qisheng Tu Jake Chen | 2017 | Bone Research2017,5,1: | 23 |
| 3 | LGR5 is a promising biomarker for patients with stage Ⅰ and Ⅱ gastric cancer显示文摘Objective: To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) expressions in gastric cancer and to evaluate its clinical significance. Methods: LGR5 expression was assessed by immunohistochemistry in 257 gastric cancer patients after surgery. The relationships between LGR5 expression and clinicopathological features and patients prognosis were statistically analyzed. Results: The expression of LGR5 was significantly higher in gastric cancers as a cancer stem cell marker than in adjacent normal tissues (P<0.001), and more frequently in patients with intestinal type, well-moderate differentiation and stage Ⅰ and Ⅱ (P<0.05). Although we found gastric cancer patients with LGR5 positive expression had a poorer prognosis, it didn't meet statistical significance (P>0.05). LGR5 negative expression was significantly related to the favorable overall survival in stage Ⅰ and Ⅱ gastric cancer patients (P<0.05). Furthermore, patients with high LGR5 expression tended to be more likely to get progression and have poorer progress-free survival (P<0.05). Multivariate Cox regression analysis revealed that LGR5 expression was an independent factor of overall survival for the patients with stage Ⅰ and Ⅱ gastric cancer (P<0.05). Conclusions: Our results show that LGR5 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of patients with stage Ⅰ and Ⅱ gastric cancer. | Zhaode Bu Zhixue Zheng Lianhai Zhang Ziyu Li Yu Sun Bin Dong Aiwen Wu Xiaojiang Wu Xiaohong Wang Xiaojing Cheng Xiaofang Xing Yingai Li Hong Du Jiafu Ji | 2013 | Chinese Journal of Cancer Research2013,25,1: | 17 |
| 4 | Arabidopsis co-chaperonin CPN20 antagonizes Mg-chelatase H subunit to derepress ABA-responsive WRKY40 transcription repressor显示文摘Our previous study demonstrated that a chloroplast co-chaperonin 20(CPN20),one of the interaction partners of the magnesium-protoporphyrin IX chelatase H subunit(CHLH/ABAR),negatively regulates ABA signaling at the same node with ABAR but upstream of WRKY40 transcription repressor in Arabidopsis thaliana.In the present experiment,we showed that ABA directly inhibits the ABAR-CPN20 interaction,and also represses expression of CPN20,which depends on ABAR.CPN20 inhibits ABAR-WRKY40 interaction by competitively binding to ABAR.ABAR downregulates,but CPN20 upregulates,WRKY40 expression.The cpn20-1 mutation induces downregulation of WRKY40,and suppresses the upregulated level of WRKY40 due to the cch mutation in the ABAR gene.ABA-induced repressive effect of the WRKY40 gene is strengthened by downregulation of CPN20 but reduced by upregulation of CPN20.Together with our previously reported genetic data,we provide evidence that CPN20 functions through antagonizing the ABAR-WRKY40 coupled pathway,and ABA relieves this pathway of repression by inhibiting the ABAR-CPN20 interaction to activate ABAR-WRKY40 interaction. | ZHANG XiaoFeng JIANG Tao YU YongTao WU Zhen JIANG ShangChuan LU Kai FENG XiuJing LIANG Shan LU YanFen WANG XiaoFang ZHANG DaPeng | 2014 | Science China(Life Sciences)2014,57,1: | 11 |
| 5 | Ezrin promotes invasion and migration of the MG63 osteosarcoma cell显示文摘 | Zhang Jian Zuo Jianhong Lei Mingsheng Wu Song Zang Xiaofang Zhang Chaoyue | 2014 | Chinese Medical Journal2014,,10: | 11 |
| 6 | Diagnostic value of 5 serum biomarkers for hepatocellular carcinoma with different epidemiological backgrounds:A large-scale,retrospective study显示文摘Objective:Hepatocellular carcinoma(HCC)is a lethal global disease that requires an accurate diagnosis.We assessed the potential of 5 serum biomarkers(AFP,AFU,GGT-II,GPC3,and HGF)in the diagnosis of HCC.Methods:In this retrospective study,we measured the serum levels of each biomarker using ELISAs in 921 participants,including 298 patients with HCC,154 patients with chronic hepatitis(CH),122 patients with liver cirrhosis(LC),and 347 healthy controls from 3 hospitals.Patients negative for hepatitis B surface antigen and hepatitis C antibody(called'NBNC-HCC')and patients positive for the above indices(called'HBV-HCC and HCV-HCC')were enrolled.The selected diagnostic model was constructed using a training cohort(n=468),and a validation cohort(n=453)was used to validate our results.Receiver operating characteristic analysis was used to evaluate the diagnostic accuracy.Results:Theα-L-fucosidase(AFU)/α-fetoprotein(AFP)combination was best able to distinguish NBNC-HCC[area under the curve:0.986(95%confidence interval:0.958–0.997),sensitivity:92.6%,specificity:98.9%]from healthy controls in the test cohort.For screening populations at risk of developing HCC(CH and LC),the AFP/AFU combination improved the diagnostic specificity for early-stage HCC[area under the curve:0.776(0.712–0.831),sensitivity:52.5%,specificity:91.6%in the test group].In all-stage HBV-HCC and HCV-HCC,AFU was also the best candidate biomarker combined with AFP[area under the curve:0.835(0.784–0.877),sensitivity 69.1%,specificity:87.4%in the test group].All results were verified in the validation group.Conclusions:The AFP/AFU combination could be used to identify NBNC-HCC from healthy controls and hepatitis-related HCC from at-risk patients. | Dongming Liu Yi Luo Lu Chen Liwei Chen Duo Zuo Yueguo Li Xiaofang Zhang Jing Wu Qing Xi Guangtao Li Lisha Qi Xiaofen Yue Xiehua Zhang Zhuoyu Sun Ning Zhang Tianqiang Song Wei Lu Hua Guo | 2021 | Cancer Biology & Medicine2021,18,1: | 10 |
| 7 | Effect of Qilongtoutong granule on calcitonin gene-related peptide,beta-endorphin, serotonin, dopamine, and noradrenalin in migraine model rats and mice显示文摘OBJECTIVE: To study the effect of Qilongtoutong granule(QLTT) on plasma calcitonin gene-related peptide(CGRP), beta-endorphin(β-EP), 5-HT, dopamine(DA), noradrenalin(NE), and blood viscosity in migraine model rats and mice.METHODS: Both the acute blood stasis model group and nitroglycerin-induced migraine model group included 60 Sprague-Dawley rats. The reserpine-reduced model group had 60 Kunming mice.Rats from each test were grouped into normal control group, model group, Zhengtian pill(ZTP)group, and high, moderate, or low-dose QLTT groups. In the acute blood stasis model test, after gavage for 7 days, rats were given 0.8 mL/kg adrenaline hydrochloride subcutaneously twice, and kept in ice water for 5 min. After fasting for 12 h,rats were anesthetized and blood samples were col-lected for detection of blood viscosity. In the nitroglycerin-induced migraine group, after gavage for7 days, rats were intraperitoneally injected nitroglycerin(10 mg/kg), and 4 h later, blood samples were collected from postcava for measuring the plasma CGRP and β-EP levels. In the reserpine-reduced model test, except the normal control group, mice were administered reserpine(0.25 mg/kg, i.h.) for 9 days. Mice received intragastric administration from the third day to the ninth day. One hour after the last gavage, blood and brain tissue samples were obtained. Then, blood clotting time and the contents of neurotransmitters were determined.RESULTS: QLTT-(3.6, 1.8, and 0.9 g/kg) and ZTP-treated rats had lower blood viscosity than that in model rats under different shear rates(P<0.01). QLTT-(3.6, 1.8 g/kg) and ZTP-treated rats had significantly lower plasma CGRP levels and higher plasma β-EP levels than those in model rats(P<0.01). QLTT treatment at dose of 0.9 g/kg had lower plasma CGRP levels as well(P<0.05). QLTT-(5.2,2.6 g/kg) and ZTP-treated mice had longer blood clotting time than that in model mice(P<0.01).QLTT-(2.6 g/kg) and ZTP-treated mice had higher plasma serotonin(5-HT) levels than those in model mice(P<0.05).CONCLUSION: QLTT-treated animals had lower plasma CGRP level, higher plasma β-EP, 5-HT, higher brain tissue 5-HT, NE, DA levels, and lower blood viscosity than those in the migraine model animals. | Xiaofang Wu Meikui Zhang Huai Huang | 2014 | Journal of Traditional Chinese Medicine2014,34,2: | 9 |
| 8 | Gluconeogenesis during starvation and refeeding phase is affected by previous dietary carbohydrates levels and a glucose stimuli during early life in Siberian sturgeon(Acipenser baerii)显示文摘Gluconeogenesis responses was assessed during a short starvation period and subsequent refeeding in Siberian sturgeon(Acipenser baerii) previously fed different dietary carbohydrates levels and experienced to a glucose stimuli during early life. The sturgeon larvae were previously fed either a high glucose diet(G) or a low glucose diet(F) from the first feeding to yolk absorption(8 to 12 d post-hatching [dph]). Each group of fish was sub-divided into 2 treatments at 13 dph and was fed either a high-carbohydrate diet(H) or a low carbohydrate diet(L) until 20 wk. In the current study, the fish in 4 groups(GL, FL, GH and FH) were experienced to starvation for 21 d following by re-feeding of their corresponding diets for 21 d.Fish were sampled at postprandial 6 and 24 h before starvation(P6 h and P24 h), starvation 7,14 and 21 d(S7, S14 and S21) and 1, 7,14 and 21 d during refeeding(R1, R7, R14 and R21). Plasma samples during refeeding were taken at P6 h at each time point. Glycaemia levels, liver and muscle glycogen contents,activities and mRNA levels of hepatic gluconeogenic enzymes were examined. We found that both dietary carbohydrate levels and early glucose stimuli significantly affected the metabolic responses to starvation and refeeding in Siberian sturgeon(P < 0.05). During prolonged starvation, Siberian sturgeon firstly mobilized the liver glycogen and then improved gluconeogenesis when the dietary carbohydrates were abundant, whereas preserved the liver glycogen stores at a stable level and more effectively promoted gluconeogenesis when the dietary carbohydrates are absent to maintain glucose homoeostasis.During refeeding, as most teleostean, Siberian sturgeon failed controlling the activities and mRNA levels of phosphoenolpyruvate carboxykinase cytosolic forms(PEPCK-C), fructose-1,6-bisphosphatase(FBPase),but particularly controlled phosphoenolpyruvate carboxykinase mitochondrial forms(PEPCK-M) activities and mRNA expression of glucose-6-phosphatase(G6 Pase, except in GL group). Siberian sturgeon has a full compensatory ability on growth, but this ability would be obstructed by early glucose stimuli when refeeding the low carbohydrate diet after S21. | Xiaofang Liang Jia Wang Guan Gong Min Xue Yingchao Dong Xiufeng Wu Xin Wang Chunshan Chen Xufang Liang Yuchang Qin | 2017 | Animal Nutrition2017,,3: | 8 |
| 9 | Aromatization over nanosized Ga-containing ZSM-5 zeolites prepared by different methods:Effect of acidity of active Ga species on the catalytic performance显示文摘Nanosized Ga-containing ZSM-5 zeolites were prepared via isomorphous substitution and impregnation followed by characterized using various techniques. The catalytic performance of the zeolites for the aromatization of 1-hexene was investigated. The results indicate that isomorphous substitution promotes the incorporation of Ga heteroatoms into the framework along with the formation of extra-framework GaO^+species([GaO^+]a) that have stronger interactions with the negative potential of the framework. In addition, based on the Py-IR results and catalytic performance, the [GaO^+]aspecies with stronger Lewis acid sites produced a better synergism with moderate Br?nsted acid sites and thus improved the selectivity to aromatic compounds. However, the impregnation results in the formation of Ga_2O_3 phase and small amounts of GaO^+species that are mainly located on the external surface([GaO^+]~b), which contribute to weaker Lewis acid sites due to weaker interactions with the zeolite framework. During 1-hexene aromatization, the nanosized Ga isomorphously substituted ZSM-5 zeolite samples(Gax-NZ5) exhibited better catalytic performance compared to the impregnated samples, and the highest aromatic yield(i.e.,65.4 wt%) was achieved over the Ga4.2-NZ5 sample, which contained with the highest Ga content. | Yujun Fang Xiaofang Su Xuefeng Bai Wei Wu Gaoliang Wang Linfei Xiao Anran Yu | 2017 | Journal of Energy Chemistry2017,26,4: | 8 |
| 10 | Diversity and redundancy of the ripening regulatory networks revealed by the fruitENCODE and the new CRISPR/Cas9 CNR and NOR mutants显示文摘Tomato is considered as the genetic model for climacteric fruits,in which three major players control the fruit ripening process:ethylene,ripening transcription factors,and DNA methylation.The fruitENCODE project has now shown that there are multiple transcriptional circuits regulating fruit ripening in different species,and H3K27me3,instead of DNA methylation,plays a conserved role in restricting these ripening pathways.In addition,the function of the core tomato ripening transcription factors is now being questioned.We have employed CRISPR/Cas9 genome editing to mutate the SBP-CNR and NAC-NOR transcription factors,both of which are considered as master regulators in the current tomato ripening model.These plants only displayed delayed or partial non-ripening phenotypes,distinct from the original mutant plants,which categorically failed to ripen,suggesting that they might be gain-of-function mutants.Besides increased DNA methylation genome-wide,the original mutants also have hyper-H3K27me3 in ripening gene loci such as ACS2,RIN,and TDR4.It is most likely that multiple genetic and epigenetic factors have contributed to their strong non-ripening phenotypes.Hence,we propose that the field should move beyond these linear and twodimensional models and embrace the fact that important biological processes such as ripening are often regulated by highly redundant network with inputs from multiple levels. | Ying Gao Ning Zhu Xiaofang Zhu Meng Wu Cai-Zhong Jiang Donald Grierson Yunbo Luo Wei Shen Silin Zhong Da-Qi Fu Guiqin Qu | 2019 | Horticulture Research2019,6,1: | 7 |
| 11 | Genetically humanized pigs exclusively expressing human insulin are generated through custom endonuclease-mediated seamless engineering显示文摘Dear Editor,Type1diabetes(T1D)isa lifelong(chronic)disease and a major health problem throughout the world.This disease can be treatedby either insulin injection or islet transplantation.Islet transplantation is considered as a better treatment for T1D patients,because islets can produce and release insulin at the appropriate time,resulting in tight blood glucose control. | Yi Yang Kepin Wang Han Wu Qin Jin Degong Ruan Zhen Ouyang Bentian Zhao Zhaoming Liu Yu Zhao Quanjun Zhang Nana Fan Qishuai Liu Shimei Guo Lei Bu Yong Fan Xiaofang Sun Xiaoping Li Liangxue Lai | 2016 | Journal of Molecular Cell Biology2016,8,2: | 6 |
| 12 | Adsorption capacity of hydrophobic SiO_2 aerogel/activated carbon composite materials for TNT显示文摘The adsorption properties of TNT from wastewater by hydrophobic silica aerogel/activated carbon composite materials were investigated. The effects of adsorption time, pH value, adsorption temperature, and the amount of the composite materials on the adsorption rate were studied. The adsorption principle and mechanism of the composite materials were discussed along with the Freundlich equation. The results showed that the best adsorption rate of the hydrophobic silica aerogel/activated car-bon composite materials could reach 96.5% with adsorption conditions of adsorption temperature 25°C, pH value 7, the amount of SiO2aerogel dosage 3.33 g/L, and adsorption time of 120 min. The adsorption of hydrophobic SiO2aero-gel/activated carbon composite materials for TNT solution is mainly surface adsorption, and also has some chemical adsorp-tion when the aerogel hydrophobicity is modified. | ZHOU XiaoFang CUI Sheng LIU Yu LIU XueYong SHEN XiaoDong WU ZhanWu | 2013 | Science China(Technological Sciences)2013,56,7: | 5 |
| 13 | A Pilot Program of Pre-Exposure and Post-Exposure Prophylaxis Promotion among Men Who Have Sex with Men-7 Study Sites, China, 2018–2019显示文摘Summary What is already known on this topic?Pre-exposure prophylaxis(PrEP)and post-exposure prophylaxis(PEP)had been proved to be effective in HIV prevention among men who have sex with men(MSM)internationally.Use of either PrEP or PEP was found to be limited among Chinese MSM.Relatively little data was reported in China. | Xiaofang Wang Jie Xu Zunyou Wu | 2020 | China CDC weekly2020,2,48: | 4 |
| 14 | Fargeted elimination of mutant mitochondria DNA in MELAS-iPSCs by mitoTALENs显示文摘 | Yi Yang Han Wu Xiangjin Kang Yanhui Liang Ting Lan Tianjie Li Tao Tan Jiangyun Peng Quanjun Zhang Geng An Yali Liu Qian Yu Zhenglai Ma Ying Lian Boon Seng Soh Qingfeng Chen Ping Liu Yaoyong Chen Xiaofang Sun Rong Li Xiumei Zhen Yang Yu Xiaoping Li Yong Fan | 2018 | Protein & Cell2018,9,3: | 4 |
| 15 | Regulation of shear stress on rolling behaviors of HL-60 cells on P-selectin显示文摘Circulating leukocytes in trafficking to the inflammatory sites, will be first tether to, and then roll on the vascular surface. This event is mediated through specific interaction of P-selectin and P-selectin glycoprotein ligand-1(PSGL-1), and regulated by hemodynamics. Poor data were reported in understanding P-selectin-mediated rolling. With the flow chamber technique, we herein observed HL-60 cell rolling on P-selectin with or without 3% Ficoll at various wall shear stresses from 0.05 to 0.4 dyn/cm2. The results demonstrated that force rather than transport regulated the rolling, similar to rolling on L- and E-selectin. The rolling was accelerated quickly by an increasing force below the optimal shear threshold of 0.15 dyn/cm2 first and then followed by a slowly decelerating phase starting at the optimum, showing a catch-slip transition and serving as a mechanism for the rolling. The catch-slip transition was completely reflected to the tether lifetime and other rolling parameters, such as the mean and fractional stop time. The narrow catch bond regime stabilized the rolling quickly, through steeply increasing fractional stop time to a plateau of about 0.85. Data presented here suggest that the low shear stress threshold serves as a mechanism for most cell rolling events through P-selectin. | LING YingChen FANG Ying YANG XiaoFang LI QuHuan LIN QinYong WU JianHua | 2014 | Science China(Physics,Mechanics & Astronomy)2014,57,10: | 4 |
| 16 | Air pollution and inhalation exposure to particulate matter of different sizes in rural households using improved stoves in central China显示文摘Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter(PM) emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China.Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4 ± 41.1, 159.3 ± 74.3, 176.7 ± 78.1 and 217.9 ± 78.1 μg/m3,respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25 μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure. | Weijian Liu Guofeng Shen Yuanchen Chen Huizhong Shen Ye Huang Tongchao Li Yilong Wang Xiaofang Fu Shu Tao Wenxin Liu Yibo Huang-Fu Weihao Zhang Chunyu Xue Guangqing Liu Fuyong Wu Minghung Wong | 2018 | Journal of Environmental Sciences2018,30,1: | 4 |
| 17 | The synergic effects of highly selective bimetallic Pt-Pd/SAPO-41 catalysts for the n-hexadecane hydroisomerization显示文摘The hydroisomerization of n-hexadecane over Pt-Pd bimetallic catalysts is an effective way to produce clean fuel oil.This work reports a useful preparation method of bimetallic bifunctional catalysts by a co-impregnation or sequential impregnation process.Furthermore,monometallic catalysts with loading either Pt or Pd are also prepared for comparison.The effects of the metal species and impregnation order on the characteristics and catalytic performance of the catalysts are investigated.The catalytic test results indicate that the maximum iso-hexadecane yield over different catalysts increases as follows:Pt/silicoaluminophosphate SAPO-41 | Guozhi Jia Chunmu Guo Wei Wang Xuefeng Bai Xiaomeng Wei Xiaofang Su Tong Li Linfei Xiao Wei Wu | 2021 | Frontiers of Chemical Science and Engineering2021,15,5: | 4 |
| 18 | Design of mixed H-two/H-infinity optimal control systems using multiobjective differential evolution algorithm显示文摘In this paper, the mixed H-two/H-infinity control synthesis problem is stated as a multiobjective opti-mization problem, with objectives of minimizing the H-two and H-infinity norms simultaneously. Instead of building a LMIs-based synthesis algorithm, a self-adaptive control parameter multiobjective differential evolution algorithm is developed directly in the controller parameters space. In the case of systems with polytopic uncertainties, the worst case norm computation is formulated as an implicit optimization problem, and the proposed self-adaptive differential evolution is employed to calculate the worst case H-two and H-infinity norms. The numerical examples illustrate the power and validity of the proposed approach for the mixed H-two/H-infinity control multiobjective optimal design. | Lianghong WU Yaonan WANG Shaowu ZHOU Xiaofang YUAN | 2013 | 控制理论与应用(英文版)2013,11,3: | 2 |
| 19 | An Improved Space-Time Joint Anti-jamming Algorithm Based on Variable Step LMS显示文摘In wireless communication,the space-time anti-jamming method is widely applied because it shows better performance than the pure airspace and pure temporal anti-jamming methods.However,its application is limited by its computational complexity,and it cannot suppress narrowband interference that is in the same direction as the navigation signal.To solve these problems,we propose improved frequency filter to filter the narrowband interference from the desired signal direction in advance,meanwhile,an improved variable step Least Mean Square(LMS) method is proposed to complete the space-time array weights with fast iteration,thereby reducing computational complexity.The simulation results show that,compared with conventional methods,the anti-jamming capability of the proposed algorithm is significantly enhanced; and its complexity is significantly reduced. | Dengao Li Jinqiang Liu Jumin Zhao Gang Wu Xiaofang Zhao | 2017 | Tsinghua Science and Technology2017,22,5: | 2 |
| 20 | Mixed mode oscillations as well as the bifurcation mechanism in a Duffing’s oscillator with two external periodic excitations显示文摘The main purpose of the paper is to present an approach to account for the mechanism of bursting oscillations occurring in the systems with multiple periodic excitations. Since the traditional slow-fast analysis method can be used only for the systems with two scales in time domain, when there exists an order gap between the exciting frequencies and the natural frequency, how to explore the mechanism of the complicated dynamics remains an open problem, especially for the case when two exciting terms exist. To explain our approach, a relative simple Duffing’s oscillator with two external periodic excitations is introduced as an example. For the case when one exciting frequency is integer times of the other exciting frequency, by employing Moivre’s equation, the two exciting terms can be transformed into the functions of one basic periodic exciting term. Regarding the basic periodic exciting term as a slow-varying parameter, the two exciting terms can be changed into the functions of the slow-varying parameter, based on which the whole model can be transformed into a generalized autonomous system with one slow-varying parameter. Equilibrium branches as well as the related bifurcations of the generalized autonomous system can be derived with the variations of the amplitudes of the two excitations, which describes the relationship between the state variables of the generalized autonomous system and the slow-varying parameter. Considering the slow-varying parameter as a generalized state variable, one may obtain the so-called transformed phase portraits, which present the relationship between the state variable and the slowvarying parameter. The bifurcation mechanism of the mixed oscillations can be obtained by overlapping the equilibrium branches and the transformed phase portraits. Upon the approach, different types of bursting oscillations are presented. It is pointed that when the trajectory moves almost strictly along the segments of the stable equilibrium branches to the fold bifurcation points, jumping phenomena to other stable equilibrium segments can be observed, leading to the repetitive spiking oscillations, which can be approximated by the transient procedure from the bifurcation points to the stable equilibrium segments. Furthermore, because of the distributions of stable segments on the equilibrium branches of the generalized autonomous system may vary with the exciting amplitudes, the forms of bursting oscillations may change. When more fold bifurcations involve in the bursting attractors, more forms of quiescent states as well as spiking states exist in the oscillations,leading to different types of bursting oscillations. | ZHANG XiaoFang ZHENG JianKang WU GuoQing BI QinSheng | 2019 | Science China(Technological Sciences)2019,62,10: | 2 |