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Large Time Behavior of Solutions to a 3D keller-Segel-Stokes System Involving a Tensor-valued Sensitivity with Saturation

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应用数学学报:英文版 2023年第4期39卷 1032-1064页

作者： Yuan-yuan ke Jia-shan ZHENG School of Mathematics Renmin University of ChinaBeijing 100872China School of Mathematics and Statistics Science Yantai UniversityYantai 264005China

In this paper we deal with the initial-boundary value problem for the coupled keller-Segel-Stokes system with rotational flux, which is corresponding to the case that the chemical is produced instead of consumed,■subject to the boundary conditions( n-n S(x, n, c) c) · ν = c · ν = 0 and u = 0, and suitably regular initial data(n0(x), c0(x), u0(x)), where ? ? R3is a bounded domain with smooth boundary ??. Here S is a chemotactic sensitivity satisfying |S(x, n, c)| ≤ CS(1 + n)-αwith some CS> 0 and α > 0. The greatest contribution of this paper is to consider the large time behavior of solutions for the system(KSS), which is still open even in the 2D case. We can prove that the corresponding solution of the system(KSS) decays to(■) exponentially, if the coefficient of chemotactic sensitivity is appropriately small. As a precondition to consider the asymptotic behavior, we also show the global existence and boundedness of the corresponding initial-boundary problem KSS with a simplified method. We find a new phenomenon that the suitably small coefficient CSof chemotactic sensitivity could benefit the global existence and boundedness of solutions to the model KSS.

关键词： Large time behavior Global existence Boundedness keller-Segel-Stokes system

Impedance Analysis Considering Unstable Subsystem Poles for MMC-HVDC-based Wind Farm Integration System

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CSEE Journal of Power and Energy Systems 2022年第2期8卷 634-639页

作者： ke Ji Hui Pang shan Liu Guangfu Tang China Electric Power Research Institute Beijing100192China Global Energy Interconnection Research Institute Beijing 102211China

Employing the AC/DC impedance analysis method,extensive research has been conducted on issues pertaining to harmonic resonance observed in wind farm-connected MMCHVDC systems over the past 5 years.In general,this method divides the studied system into two subsystems at AC and DC sections.Subsequently,the impedance produced by these subsystems can be used to determine the system stability by implementing Nyquist criterion or generalized Nyquist stability criterion.However,the existing impedance analysis methods usually assume the subsystems to be stable and disregard certain special cases with potentially unstable subsystems,where the unstable poles of these subsystems must be evaluated before applying Nyquist criterion.In view of this consideration,a simplified method for identifying unstable subsystem poles is presented in this paper.Hence,the shortcoming of existing impedance analyses is rectified by considering the unstable subsystem poles.The proposed method and the stability analyses are validated by the electromagnetic transient simulation performed in PSCAD/EMTDC.

关键词： AC/DC side impedance method harmonic resonance MMC-HVDC small-signal stability wind farm

Kunxian Capsule Extract Inhibits Angiogenesis in Zebrafish Embryos via PI3K/AKT-MAPK-VEGF Pathway

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Chinese Journal of Integrative Medicine 2023年第2期29卷 137-145页

作者： MA Rui-jiao Maharajan Kannan XIA Qing ZHANG shan-shan TU Peng-fei LIU ke-chun ZHANG Yun Biology Institute Qilu University of Technology(Shandong Academy of Sciences)Jinan 250103China Engineering Research Center of Zebrafish Models for Human Diseases and Drug Screening of shandong Province Jinan 250103China State key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China

Objective: To investigate the anti-angiogenic activity of Kunxian Capsule(KX) extract and explore the underlying molecular mechanism using zebrafish. Methods: The KX extract was prepared with 5.0 g in 100 mL of 40% methanol followed by ultrasonication and freeze drying. Freeze dried KX extract of 10.00 mg was used as test stock solution. Triptolide and icariin, the key bioactive compounds of KX were analyzed using ultra-high performance liquid chromatography. The transgenic zebrafish Tg(flk1:GFP) embryos were dechorionated at 20-h post fertilization(hpf) and treated with PTK 787, and 3.5, 7, 14 and 21 μg/m L of KX extract, respectively.After 24-h post exposure(hpe), mortality and malformation(%), intersegmental vessels(ISV) formation, and m RNA expression level of angiogenic pathway genes including phosphoinositide 3-kinase(PI3K), protein kinase B(AKT),extracellular signal-regulated kinases(ERKs), mitogen-activated protein kinase(MAPK), vascular endothelial growth factor(VEGF) and fibroblast growth factor(FGF-2) were determined. Further, the embryos at 72 hpf were treated with KX extract to observe the development of sub-intestinal vein(SIV) after 24 hpe. Results: The chromatographic analysis of test stock solution of KX extract showed that triptolide and icariin was found as 0.089 mg/g and 48.74 mg/g, respectively, which met the requirements of the national drug standards. In zebrafish larvae experiment, KX extract significantly inhibited the ISV(P<0.01) and SIV formation(P<0.05). Besides, the m RNA expression analysis showed that KX extract could significantly suppress the expressions of PI3K and AKT,thereby inhibiting the m RNA levels of ERKs and MAPK. Moreover, the downstream signaling cascade affected the expression of VEGF and its receptors(VEGFR and VEGFR-2). FGF-2, a strong angiogenic factor, was also downregulated by KX treatment in zebrafish larvae. Conclusion: KX extract exhibited anti-angiogenic effects in zebrafish embryos by regulating PI3K/AKT-MAPK-VEGF pathway and showed promising potential for RA

关键词： angiogenesis rheumatoid arthritis synovial inflammation osteoporosis Chinese medicine

PRRT2 Mutation and Serum Cytokines in Paroxysmal Kinesigenic Dyskinesia

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Current Medical Science 2022年第2期42卷 280-285页

作者： ke XU shan-shan HUANG Dao-yuan YUE Guo LI Sui-qiang ZHU Xiao-yan LIU Department of Neurology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Department of Laboratory Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China

Objective Paroxysmal kinesigenic dyskinesia(PKD)is a rare movement disorder PRRT2 gene mutations have been reported to cause PKD.However,the pathophysiological mechanism of PKD remains unclear,and it is unknown whether an inflammatory response is involved in the occurrence of this disease.We aimed to investigate the symptomatology,genotype,and serum cytokines of patients with PKD.Methods We recruited 21 patients with PKD,including 7 with familial PKD and 14 with sporadic PKD.Their clinical features were investigated,and blood samples were collected,and PRRT2 mutations and cytokine levels were detected.Results The mean age at PKD onset was 12.3±2.2 years old.Dystonia was the most common manifestation of dyskinesia,and the limbs were the most commonly affected parts.All attacks were induced by identifiable kinesigenic triggers,and the attack durations were brief(A)were previously undocumented.The tumor necrosis factor(TNF)-αlevel in the PKD group was significantly higher than that in the age-and sex-matched control group(P=0.025).There were no significant differences in the interleukin(IL)-1β,IL-2R,IL-6,IL-8,or IL-10 levels between the two groups.Conclusion In this study,we summarized the clinical and genetic characteristics of PKD.We found that the serum TNF-αlevels were elevated in patients clinically diagnosed with PKD,suggesting that an inflammatory response is involved in the pathogenesis of PKD.

关键词： paroxysmal kinesigenic dyskinesia proline-rich transmembrane protein 2 cytokines

Effects of anesthetic depth on postoperative pain and delirium:a meta-analysis of randomized controlled trials with trial sequential analysis

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Chinese Medical Journal 2022年第23期135卷 2805-2814页

作者： Yuqin Long Xiaomei Feng Hong Liu Xisheng shan Fuhai Ji ke Peng Department of Anesthesiology First Affiliated Hospital of Soochow UniversitySuzhouJiangsu 215006China Institute of Anesthesiology Soochow UniversitySuzhouJiangsu 215006China Department of Anesthesiology University of Utah HealthSalt Lake CityUTUSA Department of Anesthesiology and Pain Medicine University of California Davis HealthSacramentoCA

Background:Whether anesthetic depth affects postoperative outcomes remains controversial.This meta-analysis aimed to evaluate the effects of deepvs.light anesthesia on postoperative pain,cognitive function,recovery from anesthesia,complications,and mortality.Methods:PubMed,EMBASE,and Cochrane CENTRAL databases were searched until January 2022 for randomized controlled trials comparing deep and light anesthesia in adult surgical patients.The co-primary outcomes were postoperative pain and delirium(assessed using the confusion assessment method).We conducted a meta-analysis using a random-effects model.We assessed publication bias using the Begg’s rank correlation test and Egger’s linear regression.We evaluated the evidence using the trial sequential analysis and Grading of Recommendations Assessment,Development and Evaluation(GRADE)methodology.We conducted subgroup analyses for pain scores at different postoperative time points and delirium according to cardiac or non-cardiac surgery.Results:A total of 26 trials with 10,743 patients were included.Deep anesthesia compared with light anesthesia(a mean difference in bispectral index of-12 to-11)was associated with lower pain scores at rest at 0 to 1 h postoperatively(weighted mean difference=-0.72,95%confidence interval[CI]=-1.25 to-0.18,P=0.009;moderate-quality evidence)and an increased incidence of postoperative delirium(24.95%vs.15.92%;risk ratio=1.57,95%CI=1.28-1.91,P<0.0001;high-quality evidence).No publication bias was detected.For the exploratory secondary outcomes,deep anesthesia was associated with prolonged postoperative recovery,without affecting neurocognitive outcomes,major complications,or mortality.In the subgroup analyses,the deep anesthesia group had lower pain scores at rest and on movement during 24 h postoperatively,without statistically significant subgroup differences,and deep anesthesia was associated with an increased incidence of delirium after non-cardiac and cardiac surgeries,without statistically significant subgroup differences.Conclusion

关键词： Anesthetic depth GRADE level of evidence Postoperative delirium Postoperative pain Trial sequential analysis

Actuation Spaces Synthesis of Lower-Mobility Parallel Mechanisms Based on Screw Theory

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Chinese Journal of Mechanical Engineering 2021年第1期34卷 280-291页

作者： Shihua Li Yanxia shan Jingjun Yu Yaxiong ke Hebei Provincial key Laboratory of Parallel Robot and Mechatronic Systems Yanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China School of Liren Yanshan UniversityQinhuangdao 066004China Robotics Institute Beihang UniversityBeijing 100191China

The lower-mobility parallel mechanism has been widely used in the engineering field due to its numerous excellent characteristics.However,little work has been devoted to the actuator selection and placement that best satisfy the system's functional requirements during concept design.In this study,a unified approach for synthesizing the actuation spaces of both rigid and flexure parallel mechanisms has been presented,and all possible combinations of inputs could be obtained,laying a theoretical foundation for the subsequent optimization of inputs.According to the linear independence of actuation space and constraint space of the lower-mobility parallel mechanism,a general expression of actuation spaces in the format of screw systems is deduced,a unified synthesis process for the lower-mobility parallel mechanism is derived,and the efficiency of the method is validated with two selective examples based on screw theory.This study presents a theoretical framework for the input selection problems of parallel mechanisms,aiming to help designers select and place actuators in a correct and even optimal way after the configuration design.

关键词： Lower-mobility parallel mechanism Screw theory Actuation space Actuator placement Input selection

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柯杉——摄影作品

外语艺术教育研究 2018年第4期 56-56页

作者：柯杉广东省外语艺术职业学院艺术设计学院

作品说明:世界摄影大师法国摄影家卡蒂埃-布勒松提出'决定性瞬间'理念,并于1952年以'决定性瞬间'为书名和序言标题,出版了他的摄影作品选集。此后,'决定性瞬间'便成为世界现实主义摄影家及新闻摄影记者共同遵循的摄影美学经典。'所谓决... 详细信息

作品说明:世界摄影大师法国摄影家卡蒂埃-布勒松提出'决定性瞬间'理念,并于1952年以'决定性瞬间'为书名和序言标题,出版了他的摄影作品选集。此后,'决定性瞬间'便成为世界现实主义摄影家及新闻摄影记者共同遵循的摄影美学经典。'所谓决定性瞬间,通俗来讲就是在某个事件进行过程中,恰好在某一个瞬间,所有元素(人物、光线、物体等)均各得其所,并同时展现出特定内涵和意义,而摄影师也恰好在这一瞬间按下了快门,将所有元素记录下来。

关键词：摄影作品决定性瞬间摄影家

An insoluble polysaccharide from the sclerotium of Poria cocos improves hyperglycemia, hyperlipidemia and hepatic steatosis in ob/ob mice via modulation of gut microbiota

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Chinese Journal of Natural Medicines 2019年第1期17卷 3-14页

作者： SUN shan-shan WANG Kai MA ke BAO Li LIU Hong-Wei School of Life Sciences University of Science and Technology of China State key Laboratory of Mycology Institute of MicrobiologyChinese Academy of Sciences University of Chinese Academy of Sciences

Metabolic syndrome characterized by obesity, hyperglycemia and liver steatosis is becoming prevalent all over the world. Herein, a water insoluble polysaccharide(WIP) was isolated and identified from the sclerotium of Poria cocos, a widely used Traditional Chinese Medicine. WIP was confirmed to be a(1-3)-β-D-glucan with an average Mw of 4.486 × 10~6 Da by NMR and SEC-RI-MALLS analyses. Furthermore, oral treatment with WIP from P. cocos significantly improved glucose and lipid metabolism and alleviated hepatic steatosis in ob/ob mice. 16 S DNA sequencing analysis of cecum content from WIP-treated mice indicated the increase of butyrate-producing bacteria Lachnospiracea, Clostridium. It was also observed that WIP treatment elevated the level of butyrate in gut, improved the gut mucosal integrity and activated the intestinal PPAR-γ pathway. Fecal transplantation experiments definitely confirmed the causative role of gut microbiota in mediating the benefits of WIP. It is the first report that the water insoluble polysaccharide from the sclerotium of P. cocos modulates gut microbiota to improve hyperglycemia and hyperlipidemia. Thereby, WIP from P. cocos, as a prebiotic, has the potential for the prevention or cure of metabolic diseases and may elucidate new mechanism for the efficacies of this traditional herbal medicine on the regulation of lipid and glucose metabolism.

关键词： Poria cocos Water insoluble polysaccharide Metabolic syndrome Prebiotics Gut microbiota

Enhanced Bio-corrosion Resistance by Cu Alloying in a Micro-alloyed Pipeline Steel

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Acta Metallurgica Sinica(English Letters) 2022年第10期35卷 1731-1743页

作者： Yunpeng Zeng Wei Yan Xianbo Shi Maocheng Yan Yiyin shan ke Yang School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China CAS key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

On the composition base of commercial X65 grade pipeline steels,a Cu modified pipeline steel was designed to show improved resistance to microbially induced corrosion(MIC).The mechanical properties of the Cu-added steel and its corrosion behavior in a soil solution inoculated with sulfate-reducing bacteria(SRB)were investigated in this work.The results demonstrated that Cu-added steel exhibits a good combination of strength and toughness.Cu ions released from the Cu-added steel could effectively kill the SRB attaching on the steel surface,thus evidently decreased the pit depth and diameter of Cu-added steel.Furthermore,during the long-term immersion,the Cu-rich film formed by the enrichment of Cu in the corrosion product layer on the steel surface could also contribute to the improvement of the bio-corrosion resistance of Cu-added steel.

关键词： Pipeline steel Mechanical property Microbiologically influenced corrosion Cu alloyed steel Corrosion mechanism Sulfate-reducing bacteria(SRB)