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Truly optimal semi-active damping to control free vibration of a single degree of freedom system

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 142-145页

作者： Viet Duc La Ngoc Tuan Nguyen Institute of Mechanics Vietnam Academy of Science and TechnologyHanoi 10000Vietnam Graduate University of science and Technology Vietnam Academy of Science and TechnologyHanoi 10000Vietnam

This paper studies a single degree of freedom system under free vibration and controlled by a general semiactive damping.A general integral of squared error is considered as the performance index.A one-time switching damping controller is proposed and optimized.The pontryagin maximum principle is used to prove that no other form of semi-active damping can provide the better performance than the proposed one-time switching damping.

关键词： Analytical optimization Quadratic integral Lyapunov equation Pontryagin maximum principle

Transcranial Magneto-Acoustic Stimulation Attenuates Synaptic Plasticity Impairment through the Activation of Piezo1 in Alzheimer’s Disease Mouse Model

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Research 2024年第1期2023卷 81-95页

作者： Fangxuan Chu Ruxin Tan Xin Wang Xiaoqing Zhou Ren Ma Xiaoxu Ma Ying Li Ruixu Liu Chunlan Zhang Xu Liu Tao Yin Zhipeng Liu Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical CollegeTianjin300192China Tianjin Institutes of health science Tianjin301600China Neuroscience Center Chinese Academy of Medical Science&Peking Union Medical CollegeBeijing100730China

The neuropathological features of Alzheimer’s disease include amyloid plaques.Rapidly emerging evidence suggests that Piezo1,a mechanosensitive cation channel,plays a critical role in transforming ultrasound-related mechanical stimuli through its trimeric propeller-like structure,but the importance of Piezo1-mediated mechanotransduction in brain functions is less appreciated.However,apart from mechanical stimulation,Piezo1 channels are strongly modulated by voltage.We assume that Piezo1 may play a role in converting mechanical and electrical signals,which could induce the phagocytosis and degradation of Aβ,and the combined effect of mechanical and electrical stimulation is superior to single mechanical stimulation.Hence,we design a transcranial magneto-acoustic stimulation(TMAS)system,based on transcranial ultrasound stimulation(TUS)within a magnetic field that combines a magnetoacoustic coupling effect electric field and the mechanical force of ultrasound,and applied it to test the above hypothesis in 5xFAD mice.Behavioral tests,in vivo electrophysiological recordings,Golgi–Cox staining,enzyme-linked immunosorbent assay,immunofluorescence,immunohistochemistry,real-time quantitative PCR,Western blotting,RNA sequencing,and cerebral blood flow monitoring were used to assess whether TMAS can alleviate the symptoms of AD mouse model by activating Piezo1.

关键词： stimulation Alzheimer Piezo1

Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental sciences 2024年第3期137卷 716-731页

作者： Yifu Xu Wenjing Liu Bing Xu Zhifang Xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation academy for Earth science Chinese Academy of SciencesBeijing 100029China University of Chinese academy of sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by humans.To understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were investigated.These rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global average.The δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,respectively.The end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate gradients.Multiple isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid environment.Based on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely exposed.While the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier environment.Besides,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

Mulberry leaf supplementation inhibits skatole deposition by regulating gut microbiota and upregulating liver cytochrome P4501A1 expression in finishing pigs

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Animal Nutrition 2024年第1期16卷 34-44页

作者： Yuqing Sun Xiaoming Men Tianbao Lin Bo Deng Shi Zhong Jinxi Huo Kaipeng Qin Zhiqiang Lv Ziwei Xu Yougui Li Institute of Sericulture and Tea Zhejiang Academy of Agricultural Sciences Institute of Animal Husbandry and Veterinary science Zhejiang Academy of Agricultural Sciences

Skatole, a strong fecal odor substance, is generated through microbial degradation of tryptophan in the animal hindgut. It easily accumulates in adipose tissue and affects meat quality. In this study, the effect of mulberry leaf supplementation on skatole in finishing pigs was studied. In a 35-day trial, 20 finishing pigs (barrows and gilts) were fed with a basal diet or basal diet with 6% mulberry leaves. Growth performance of the pigs (n=10) was automatically recorded by a performance-testing feeder system and 8 pigs in each treatment were slaughtered and sampled for the remaining tests. Skatole and short-chain fatty acids were detected using HPLC and gas chromatography, respectively. Fecal microbiota were analyzed using 16S r RNA gene sequencing. The metabolomics analysis of feces and serum was performed with UHPLC-MS/MS. The major cytochrome P450 (CYP) enzymes that catalyze skatole degradation in the liver were tested by using RT-PCR and Western blot. Effects of major bioactive compounds in mulberry leaves on the CYP genes were verified in the hepatic cell line Hep G2 in an in vitro test (n=3). In finishing pigs, mulberry leaf supplementation had no significant effect on the average daily gain, average daily feed intake, and feed conversion ratio (P>0.05), but reduced skatole levels in feces, serum, and backfat (P<0.05), and increased acetic acid levels in feces (P=0.027). Mulberry leaf supplementation decreased the relative abundance of the skatole-producing bacteria Megasphaera and Olsenella (P<0.05). Indole-3acetic acid, the intermediate that is essential for skatole production, was significantly reduced in feces by mulberry leaf supplementation (P<0.05) and was positively correlated with skatole content in feces (P=0.004). In pigs treated with mulberry leaves, liver CYP1A1 expression was increased (P<0.05) and was negatively correlated with skatole content in backfat (P=0.045). The in vitro test demonstrated that mulberry leaf polyphenols and polysaccharides could directly stimulate CYP1A1 expression in h

关键词： Pig Skatole Mulberry leaf Microbiota Cytochrome P450

Effectiveness of craniosacral therapy,Bowen therapy,static touch and standard exercise program on sleep quality in fibromyalgia syndrome:A randomized controlled trial

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Journal of Integrative Medicine 2024年第4期22卷 473-483页

作者： Reepa Avichal Ughreja Prem Venkatesan Dharmanand Balebail Gopalakrishna Yogesh Preet Singh Vani Lakshmi R Department of Physiotherapy Manipal College of Health ProfessionsManipal Academy of Higher Education Department of Rheumatology Manipal Hospital Department of Clinical Immunology and Rheumatology All India Institute of Medical Sciences Department of Data science Prasanna School of Public HealthManipal Academy of Higher Education

Background:Sleep disturbance is commonly seen in fibromyalgia syndrome (FMS);however,high quality studies involving manual therapies that target FMS-linked poor sleep quality are lacking for the Indian population.Objective:Craniosacral therapy (CST),Bowen therapy and exercises have been found to influence the autonomic nervous system,which plays a crucial role in sleep physiology.Given the paucity of evidence concerning these effects in individuals with FMS,our study tests the effectiveness of CST,Bowen therapy and a standard exercise program against static touch (the manual placebo group) on sleep quality in FMS.Design,setting,participants and intervention:A placebo-controlled randomized trial was conducted on132 FMS participants with poor sleep at a hospital in Bangalore.The participants were randomly allocated to one of the four study groups,including CST,Bowen therapy,standard exercise program,and a manual placebo control group that received static touch.CST,Bowen therapy and static touch treatments were administered in once-weekly 45-minute sessions for 12 weeks;the standard exercise group received weekly supervised exercises for 6 weeks with home exercises until 12 weeks.After 12 weeks,all study participants performed the standard exercises at home for another 12 weeks.Main outcome measures:Sleep quality,pressure pain threshold (PPT),quality of life and fibromyalgia impact,physical function,fatigue,pain catastrophizing,kinesiophobia,and positive–negative affect were recorded at baseline,and at weeks 12 and 24 of the intervention.Results:At the end of 12 weeks,the sleep quality improved significantly in the CST group (P=0.037) and Bowen therapy group (P=0.023),and the PPT improved significantly in the Bowen therapy group(P=0.002) and the standard exercise group (P<0.001),compared to the static touch group.These improvements were maintained at 24 weeks.No between-group differences were observed for other secondary outcomes.Conclusion:CST and Bowen therapy improved sleep quality,and Bowen therapy and standard

关键词： Chronic pain Complementary therapies Exercise Fibromyalgia Musculoskeletal manipulations Sleep

Enhancing cut selection through reinforcement learning

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science China Mathematics 2024年第6期67卷 1377-1394页

作者： Shengchao Wang Liang Chen Lingfeng Niu Yu-Hong Dai academy of Mathematics and Systems science Chinese Academy of SciencesBeijing100190China Research Center on Fictitious Economy and Data science Chinese Academy of SciencesBeijing100190China

With the rapid development of artificial intelligence in recent years,applying various learning techniques to solve mixed-integer linear programming(MILP)problems has emerged as a burgeoning research domain.Apart from constructing end-to-end models directly,integrating learning approaches with some modules in the traditional methods for solving MILPs is also a promising direction.The cutting plane method is one of the fundamental algorithms used in modern MILP solvers,and the selection of appropriate cuts from the candidate cuts subset is crucial for enhancing efficiency.Due to the reliance on expert knowledge and problem-specific heuristics,classical cut selection methods are not always transferable and often limit the scalability and generalizability of the cutting plane method.To provide a more efficient and generalizable strategy,we propose a reinforcement learning(RL)framework to enhance cut selection in the solving process of MILPs.Firstly,we design feature vectors to incorporate the inherent properties of MILP and computational information from the solver and represent MILP instances as bipartite graphs.Secondly,we choose the weighted metrics to approximate the proximity of feasible solutions to the convex hull and utilize the learning method to determine the weights assigned to each metric.Thirdly,a graph convolutional neural network is adopted with a self-attention mechanism to predict the value of weighting factors.Finally,we transform the cut selection process into a Markov decision process and utilize RL method to train the model.Extensive experiments are conducted based on a leading open-source MILP solver SCIP.Results on both general and specific datasets validate the effectiveness and efficiency of our proposed approach.

关键词： reinforcement learning mixed-integer linear programming cutting plane method cut selection

Versatile strategies for adult neurogenesis:avenues to repair the injured brain

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Neural Regeneration Research 2024年第4期19卷 774-780页

作者： Junyi Zhao Siyu Liu Xianyuan Xiang Xinzhou Zhu The Brain Cognition and Brain Disease Institute(BCBDI) Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences Faculty of Life and health sciences Shenzhen Institutes of Advanced TechnologyChinese Academy of Sciences Shenzhen-Hong Kong Institute of Brain science-Shenzhen Fundamental Research Institutions

Brain injuries due to trauma or stroke are major causes of adult death and disability.Unfortunately,few interventions are effective for post-injury repair of brain tissue.After a long debate on whether endogenous neurogenesis actually happens in the adult human brain,there is now substantial evidence to support its occurrence.Although neurogenesis is usually significantly stimulated by injury,the reparative potential of endogenous differentiation from neural stem/progenitor cells is usually insufficient.Alternatively,exogenous stem cell transplantation has shown promising results in animal models,but limitations such as poor long-term survival and inefficient neuronal differentiation make it still challenging for clinical use.Recently,a high focus was placed on glia-to-neuron conversion under single-factor regulation.Despite some inspiring results,the validity of this strategy is still controversial.In this review,we summarize historical findings and recent advances on neurogenesis strategies for neurorepair after brain injury.We also discuss their advantages and drawbacks,as to provide a comprehensive account of their potentials for further studies.

关键词： adult neurogenesis glia-to-neuron conversion ischemic stroke neurogenic niche neuroinflammation stem cell transplantation traumatic brain injury

Analyses of Political Crisis Impact on Tourism: A Panel Counterfactual Approach with Internet Search Index

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Journal of Systems science & Complexity 2024年第4期37卷 1581-1603页

作者： HUANG Bai SUN Yuying YANG Boyu School of Statistics and Mathematics Central University of Finance & Economics academy of Mathematics and Systems science Chinese Academy of Sciences Center for Forecasting science Chinese Academy of Sciences School of Economics and Management University of Chinese Academy of Sciences

Existing research has shown that political crisis events can directly impact the tourism industry. However, the current methods suffer from potential changes of unobserved variables, which poses challenges for a reliable evaluation of the political crisis impacts. This paper proposes a panel counterfactual approach with Internet search index, which can quantitatively capture the change of crisis impacts across time and disentangle the effect of the event of interest from the rest. It also provides a tool to examine potential channels through which the crisis may affect tourist outflows.This research empirically applies the framework to analyze the THAAD event on tourist flows from the Chinese Mainland to South Korea. Findings highlight the strong and negative short-term impact of the political crisis on the tourists' intentions to visit a place. This paper provides essential evidence to help decision-makers improve the management of the tourism crisis.

关键词： Composite search index counterfactual analysis political crisis search query data tourism demand

Threshold Selection and Resource Allocation for Quantized Identification

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Journal of Systems science & Complexity 2024年第1期37卷 204-229页

作者： WANG Ying LI Xin ZHAO Yanlong ZHANG Ji-Feng Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical sciences University of Chinese Academy of SciencesBeijing 100049China

This paper is concerned with the optimal threshold selection and resource allocation problems of quantized identification, whose aims are improving identification efficiency under limited resources. Firstly, the first-order asymptotically optimal quantized identification theory is extended to the weak persistent excitation condition. Secondly, the characteristics of time and space complexities are established based on the Cramér-Rao lower bound of quantized systems. On these basis, the optimal selection methods of fixed thresholds and adaptive thresholds are established under aperiodic signals, which answer how to achieve the best efficiency of quantized identification under the same time and space complexity. In addition, based on the principle of maximizing the identification efficiency under a given resource, the optimal resource allocation methods of quantized identification are given for the cases of fixed thresholds and adaptive thresholds, respectively, which show how to balance time and space complexity to realize the best identification efficiency of quantized identification.

关键词： Quantized output resource allocation system identification threshold selection.