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Three Types of Isocoumarins with Unusual Carbon Skeletons from Artemisia dubia var. subdigitata and Their Antihepatoma Activity

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Chinese Journal of Chemistry 2024年第16期42卷 1901-1912页

作者： Ke-Xin Yang tian-Ze Li Yun-Bao Ma Yong-Cui Wang feng-Jiao Li Ji-Jun chen State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China University of Chinese Academy of Sciences Beijing 100049China

Ten novel isocoumarins,including four pairs of enantiomers,were isolated from Artemisia dubia ***(Asteraceae).Compounds 1,2 and 3a/3b possessed a unique 6/6/6-tricyclic system comprising an unusual 1-(2-methylcyclohexyl)propan-1-one moiety fused with isocoumarin core *** 4a/4b were characterized as an unexpected 2,5-dimethylcyclohexan-1-one scaffold,and compounds 5a/5b and 6a/6b were rare 1,*** structures and absolute configurations were elucidated through spectroscopic data,X-ray crystallography,ECD and NMR calculations with DP4+*** biosynthetic pathways were proposed from the naturally occurring *** pharmacological analysis suggested that the targets of compound 1 were significantly enriched in the cell cycle and Pl3K-Akt signaling *** molecular docking revealed that compound 1 had high binding affinity with CDK2(total score:6.8717).Furthermore,compounds 1 and 2 exhibited inhibitory activity on three human hepatoma cell lines,with inhibitory ratios of 85.1% and 84.5%(HepG2),88.2% and 87.3%(Huh7),and 69.2% and 69.1%(SK-Hep-1)at 200μmol·L^(-1),respectively.

关键词： Artemisia dubia var.subdigitata Isocoumarins Antihepatoma activity Cancer Natural products X-ray diffraction

Interfacial tribochemical kinetics: A new perspective on superlubricity of diamond-like carbon films

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Science China(Technological Sciences) 2024年第7期67卷 2050-2052页

作者： chen WeiQi MA tian-Bao State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

Friction is considered one of the primary challenges affecting the performance of machine operations and is a significant source of energy loss in industrial applications. About 30%of disposable energy is consumed by ... 详细信息

关键词： kinetics friction operations

Banxia Xiexin Decoction Alleviated Cerebral Glucose Metabolism Disorder by Regulating Intestinal Microbiota in APP/PS1 Mice

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Chinese Journal of Integrative Medicine 2024年第8期30卷 701-712页

作者： GAO chen-yan QIN Gao-feng ZHENG Ming-cui tian Mei-jing HE Yan-nan WANG Peng-wen Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing Dongzhimen HospitalBeijing University of Chinese MedicineBeijing100700China Neurology Department Binzhou Medical University HospitalBinzhouShandong Province256603China

Objective To identify whether Banxia Xiexin Decoction(BXD)alleviates cerebral glucose metabolism disorder by intestinal microbiota regulation in APP/PS1 *** Forty-five 3-month-old male APP/PS1 mice were divided into 3 groups using a random number table(n=15 per group),including a model group(MG),a liraglutide group(LG)and a BXD group(BG).Fifteen 3-month-old male C57BL/6J wild-type mice were used as the control group(CG).Mice in the BG were administered BXD granules by gavage at a dose of 6 g/(kg·d)for 3 months,while mice in the LG were injected intraperitoneally once daily with Liraglutide Injection(25 nmol/kg)for 3 ***,liquid chromatography with tandem-mass spectrometry was used to analyze the active components of BXD granules and the medicated serum of ***,the cognitive deficits,Aβpathological change and synaptic plasticity markers,including synaptophysin(SYP)and postsynaptic density protein 95(PSD95),were measured in APP/PS1 *** glucose uptake was detected by micropositron emission *** microbial constituents were detected by 16S rRNA *** levels of intestinal glucagon-like peptide 1(GLP-1)and cerebral GLP-1 receptor(GLP-1R),as well as the phosphoinositide-3-kinase/protein kinase B/glycogen synthase kinase-3β(PI3K/Akt/GSK3β)insulin signaling pathway were determined by immunohistochemical(IHC)staining and Western blot analysis,*** BXD ameliorated cognitive deficits and Aβpathological features(P<0.01).The expressions of SYP and PSD95 in the BG were higher than those in the MG(P<0.01).Brain glucose uptake in the BG was higher than that in the MG(P<0.01).The intestinal microbial composition in the BG was partially *** levels of intestinal GLP-1 in the BG were higher than those in the MG(P<0.01).Compared with the MG,the expression levels of hippocampal GLP-1R,Akt,PI3K and p-PI3K in the BG were significantly increased(P<0.01),while the levels of GSK3βwere reduced(P<0.01).Conclusion BXD

关键词： Banxia Xiexin Decoction Alzheimer's disease intestinal microbiota glucagon-like peptide 1 cerebral insulin resistance phosphoinositide-3-kinase/proteinkinase B/glycogen synthase kinase-3β Chinese medicine

Particle Discontinuous Deformation Analysis of Static and Dynamic Crack Propagation in Brittle Material

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2215-2236页

作者： Zediao chen feng Liu State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin300072China

Crack propagation in brittle material is not only crucial for structural safety evaluation,but also has a wideranging impact on material design,damage assessment,resource extraction,and scientific research.A thorough investigation into the behavior of crack propagation contributes to a better understanding and control of the properties of brittle materials,thereby enhancing the reliability and safety of both materials and *** an implicit discrete elementmethod,the Discontinuous Deformation Analysis(DDA)has gained significant attention for its developments and applications in recent *** these developments,the particle DDA equipped with the bonded particle model is a powerful tool for predicting the whole process of material from continuity to *** primary objective of this research is to develop and utilize the particle DDAtomodel and understand the complex behavior of cracks in brittle materials under both static and dynamic *** particle DDA is applied to several classical crack propagation problems,including the crack branching,compact tensile test,Kalthoff impact experiment,and tensile test of a rectangular plate with a *** evolutions of cracks under various stress or geometrical conditions are carefully *** simulated results are compared with the experiments and other numerical *** is found that the crack propagation patterns,including crack branching and the formation of secondary cracks,can be well *** results show that the particle DDA is a qualified method for crack propagation problems,providing valuable insights into the fracture mechanism of brittle materials.

关键词： Discontinuous deformation analysis particle DDA crack propagation crack branching brittle materials

Degradation-adaptive neural network for jointly single image dehazing and desnowing

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Frontiers of Computer Science 2024年第2期18卷 247-249页

作者： Erkang chen Sixiang chen tian YE Yun LIU School of Ocean Information Engineering Jimei UniversityXiamen 361021 China College of Artificial Intelligence Southwest UniversityChongqing 400715 China

1 Introduction In harsh winter scenes,the captured images often suffer from hazeand snowdegradationssimultaneously,which significantly affect the performance of high-level computer vision ***,most existing dehazing methods[1-4]and desnowing methods[5-7]are specialized to address only one type of weather-related degradation,and they struggle to effectively handle multiple types of degradations.

关键词： neural handle computer

A dynamical neural network approach for distributionally robust chance-constrained Markov decision process

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Science China Mathematics 2024年第6期67卷 1395-1418页

作者： tian Xia Jia Liu Zhiping chen School of Mathematics and Statistics Xi’an Jiaotong UniversityXi’an710049China

In this paper,we study the distributionally robust joint chance-constrained Markov decision *** the logarithmic transformation technique,we derive its deterministic reformulation with bi-convex terms under the moment-based uncertainty *** cope with the non-convexity and improve the robustness of the solution,we propose a dynamical neural network approach to solve the reformulated optimization *** results on a machine replacement problem demonstrate the efficiency of the proposed dynamical neural network approach when compared with the sequential convex approximation approach.

关键词： Markov decision process chance constraints distributionally robust optimization moment-based ambiguity set dynamical neural network

Stabilizing semi-transparent perovskite solar cells with a polymer composite hole transport layer

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Nano Research 2024年第3期17卷 1500-1507页

作者： Yongbin Jin Huiping feng Zheng Fang Liu Yang Kaikai Liu Bingru Deng Jingfu chen Xueling chen Yawen Zhong Jinxin Yang chengbo tian Liqiang Xie Zhanhua Wei Xiamen Key Laboratory of Optoelectronic Materials and Advanced Manufacturing Institute of Luminescent Materials and Information DisplaysCollege of Materials Science and EngineeringHuaqiao UniversityXiamen 361021China

Semi-transparent perovskite solar cells(ST-PSCs)have broad applications in building integrated ***,the stability of ST-PSCs needs to be improved,especially in n-i-p ST-PSCs since the doped 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene(Spiro-OMeTAD)is unstable at elevated temperatures and high *** this work,aπ-conjugated polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione)](PBDB-T)is selected to form a polymer composite hole transport layer(HTL)with *** sulfur atom of the thiophene unit and the carbonyl group of the polymer interact with the undercoordinated Pb2+at the perovskite surface,which stabilizes the perovskite/HTL interface and passivates the interfacial *** incorporation of the polymer also increases the glass transition temperature and the moisture resistance of *** a result,we obtain ST-PSCs with a champion efficiency of 13.71%and an average visible light transmittance of 36.04%.Therefore,a high light utilization efficiency of 4.94%can be ***,the encapsulated device can maintain 84%of the initial efficiency after 751 h under continuous one-sun illumination(at 30%relative humidity)at the open circuit and the unencapsulated device can maintain 80%of the initial efficiency after maximum power tracking for more than 1250 h under continuous one-sun illumination.

关键词： semi-transparent solar cells π-conjugated polymer composite hole transport layer building integrated photovoltaics

Recent Advances in Deciphering the Mechanisms and Biological Functions of DNA Demethylation

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Chinese Journal of Chemistry 2024年第6期42卷 645-651页

作者： Yang feng Sheng-Jun chen Bi-feng Yuan Key Laboratory of Aquatic Product Processing Ministry of Agriculture and Rural AffairsNational R&D Center for Aquatic Product ProcessingSouth China Sea Fisheries Research InstituteChinese Academy of Fishery SciencesGuangzhouGuangdong510300 China School of Public Health Research Center of Public HealthRenmin Hospital of Wuhan UniversityWuhan UniversityWuhanHubei430071 China

5-Methylcytosine (5mC) is a dynamic and reversible epigenetic modification in genomic DNA of higher *** has been well-established that the demethylation of 5mC occurs through the ten-eleven translocation (TET)-mediated oxidation of 5mC followed by thymine DNA glycosylase (TDG)-initiated base excision repair (BER).Recent findings also have identified an alternative pathway of DNA *** this pathway,TET enzymes directly oxidize 5mC to form 5-formylcytosine (5fC) or 5-carboxylcytosine (5caC).These modified bases can undergo direct deformylation or decarboxylation,***,DNA demethylation can also occur through the deamination of 5mC and 5hmC,resulting in the production of thymine and 5-hydroxymethyluracil (5hmU),*** DNA demethylation pathways possess critical functional implications and roles in biological *** Recent Advances article will focus on the studies of mechanisms and biological functions of DNA demethylation,shedding light on the reversible nature of the epigenetic modification of 5mC.

关键词： Epigenetics DNA DNA methylation 5-Methylcytosine Demethylation Mechanisms Biological functions C—C bond cleavage Mass spectrometry

Chemical derivatization strategies for enhancing the HPLC analytical performance of natural active triterpenoids

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Journal of Pharmaceutical Analysis 2024年第3期14卷 295-307页

作者： Xiao-feng Huang Ying Xue Li Yong tian-tian Wang Pei Luo Lin-Sen Qing chengdu Institute of Biology Chinese Academy of SciencesChengdu610041China State Key Laboratory for Quality Research in Chinese Medicines Macao University of Science and TechnologyMacaoChina Sichuan Center for Disease Control and Prevention Chengdu610041China University of Chinese Academy of Sciences Beijing100049China

Triterpenoids widely exist in nature,displaying a variety of pharmacological *** triterpenoids in different matrices,especially in biological samples holds great ***-performance liquid chromatography(HPLC)has become the predominant method for triterpenoids analysis due to its exceptional analytical ***,due to the structural similarities among botanical samples,achieving effective separation of each triterpenoid proves challenging,necessitating significant improvements in analytical ***,triterpenoids are characterized by a lack of ultraviolet(UV)absorption groups and chromophores,along with low ionization efficiency in mass ***,routine HPLC analysis suffers from poor *** derivatization emerges as an indispensable technique in HPLC analysis to enhance its *** the structural characteristics of triterpenoids,various derivatization reagents such as acid chlorides,rhodamines,isocyanates,sulfonic esters,and amines have been employed for the derivatization analysis of *** review comprehensively summarized the research progress made in derivatization strategies for HPLC detection of ***,the limitations and challenges encountered in previous studies are discussed,and future research directions are proposed to develop more effective derivatization methods.

关键词： Triterpenoid HPLC Derivatization Quantification