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Identification of the development stage-specific factors in mouse fetal liver binding to the human β-globin gene promoter

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cell Research 1994年第1期4卷 9-15页

作者： chen yadi YULONG HU ruolan QIAN(shanghai institute of cell biology, academia sinica shanghai 200031, china.) shanghai institute of cell biology Academia Sinica Shanghai China

In order to elucidate the molecular mechanisms of globin gene expression during embryonic development, the nuclear extracts from mouse hematopoietic tissue at different stages of development have been prepared. By using DNase I footprinting and gel mobility shift assays, the binding of protein factors in these extracts to the human βglobin promoter was analyzed. The differences in the binding patterns of protein factors during development were observed. An erythroid-specific and stage-specific nuclear protein in the nuclear extract from d 18 mouse fetal liver was identified, which can bind to the sequence (from -66bp to -90bp) of human β-globin promoter. We therefore speculate that the function of this cis-acting element may be similar to stage selector element (SSE) in chieken βA- promoter.

关键词： β-globin gene promoter trans-acting factor

Enhancing the deep-red/near-infrared fluorescence of higher rylene diimides via the chalcogen-annulation strategy

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Science china Chemistry 2024年第4期67卷 1324-1333页

作者： Kai chen Xiao chen Ke Hu Yilun Zhao Yujian Liu Guogang Liu Jinquan chen Wei Jiang zhigang Shuai Da-Hui Qu Zhaohui Wang Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistryInstitute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Key Laboratory of Organic Optoelectronics and Molecular Engineering Department of ChemistryTsinghua UniversityBeijing 100084China State Key Laboratory of Precision Spectroscopy East China Normal University500 Dongchuan RoadShanghai 200241China

Deep-red/near-infrared fluorescence is highly suitable for bioimaging owing to its ability to deeply penetrate tissues,organs,and live ***,developing organic fluorophores with high deep-red/near-infrared fluorescence quantum yield(Φ_(FL))and fluorescent brightness remain a significant challenge owing to the energy gap ***,we developed a straightforward and effective chalcogen-annulation strategy by introducing O,S and Se into the bay region of TDI and QDI fluorophores,realizing the increase ofΦFLand fluorescent brightness up to 10 *** our best knowledge,this study potentially stands as the pioneering instance showcasing the anti-heavy-atom effect of chalcogens,and the absoluteΦFL(93%)and fluorescent brightness(128,200 cm^(-1)mol^(-1)L)of Se-TDI is among top deep-red/near-infrared organic fluorophores currently *** femtosecond transient absorption(fs-TA)measurements show the absence of obvious changes of the excited state lifetime after the introduction of chalcogens in TDI and QDI fluorophores,indicating that intersystem crossing(ISC)can be neglected in TDI and QDI *** calculations further reveal the chalcogen-annulation strategy increase the radiative rates and reduce the reorganization energy of several accepting modes at the ground state in TDI fluorophores,leading to the suppression of internal conversion(IC)*** chalcogen-annulation strategy,which effectively increases the Φ_(FL)and restricts the IC processes,while remaining unaffected by the heavy-atom effect,offers novel insights and theoretical support for the design and synthesis of deep-red/near-infrared organic fluorophores with high Φ_(FL)and fluorescent brightness.

关键词： π-extended rylene diimides chalcogen-annulation strategy deep-red/near-infrared fluorescence

Structure and mechanical properties of windmill palm fiber with different delignification treatments

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Journal of Bioresources and Bioproducts 2024年第1期9卷 102-112页

作者： Changjie chen Pengfei xu Xinhou Wang Key Laboratory of Textile Science&Technology(Donghua University) Ministry of EducationCollege of Textiles2999 Renmin North RoadShanghai 201620China Basalt Fiber and Composite Key Laboratory of Sichuan Province Sichuan 635000China College of Mechanical Engineering Donghua UniversityShanghai 201620China National Engineering Laboratory for Modern Silk Soochow UniversitySuzhou 215123China shanghai Composite Technology Co.Ltd. Shanghai 201112China

The removal of lignin from natural cellulose fibers is a crucial step in preparing high-performance materials,such as compressed high-toughness *** process can eliminate non-cellulosic impurities,create abundant compressible pores,and expose a greater number of active functional *** this study,biomass waste windmill palm fiber was used as the raw mate-rial to prepare holocellulose fibers through various chemical *** structure,chemical composition,Fourier transform infrared spectroscopy analysis,X-ray diffraction analysis,ther-mal properties,and mechanical properties,particularly fatigue performance,were *** sodium chlorite treated fiber had the highest crystallinity index(61.3%)and the most complete appearance *** sodium sulfite treated fiber had the highest tensile strength(227.34±52.27)*** peroxide treatment removed most of the lignin and hemicellulose,increas-ing the cellulose content to 68.83%±0.65%.However,all the chemical treatments decreased the thermal property of the fibers.

关键词： Windmill palm fiber Delignification treatment Morphonology Mechanical property Fatigue property

An active high-static-low-dynamic-stiffness vibration isolator with adjustable buckling beams:theory and experiment

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 425-440页

作者： Kefan xu Muqing NIU Yewei ZHANG Liqun chen School of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China shanghai institute of Aircraft Mechanics and Control Shanghai 200092China

High-static-low-dynamic-stiffness(HSLDS)vibration isolators with buckling beams have been widely used to isolate external *** active adjustable device composed of proportion integration(PI)active controllers and piezoelectric actuators is proposed for improving the negative stiffness stroke of buckling beams.A nonlinear output frequency response function is used to analyze the effect of the vibration *** prototype of the active HSLDS device is built,and the verification experiment is *** results show that compared with the traditional HSLDS vibration isolator,the active HSLDS device can broaden the isolation frequency bandwidth,and effectively reduce the resonant amplitude by adjusting the active control *** maximum vibration reduction rate of the active HSLDS vibration isolator can attain 89.9%,and the resonant frequency can be reduced from 31.08 Hz to 13.28 ***,this paper devotes to providing a new design scheme for enhanced HSLDS vibration isolators.

关键词： active control high-static-low-dynamic-stiffness(HSLDS) vibration isola-tor dynamic analysis

MicroRNA (let-7b-5p)-targeted DARS2 regulates lung adenocarcinoma growth by PI3K/AKT signaling pathway

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Oncology Research 2024年第3期32卷 517-528页

作者： YUANYUAN xu XIAOKE chen Department of Oncology Surgery Shanghai Lung Cancer CenterShanghai Chest HospitalShanghai Jiao Tong UniversityShanghaiChina

Background:The aberrant intraellular expression of a mitochondrial aspartyl tRNA synthetase 2(DARS2)has been reported in human *** its critical role and detailed mechanism in lung adenocarcinoma(LUAD)remain ***:Initially,The Cancer Genome Atlas(TCGA)based Gene Expression Profiling Interactive Analysis(GEPIA)database (http:/***/)was used to analyze the prognostic relevance of DARS2 expression in ***,cell counting kit(CCK)8,immunostaining,and transwell invasion assays in LUAD cell lines in vitro,as well as DARS2 silence on LUAD by tumorigenicity experiments in wivo in nude mice,were ***,we analyzed the expression levels of p-PI3K(phosphorylated Phosphotylinosital3 kinase),PI3K,AKT(Protein Kinase B),p-AKT(phosphorylated Protein Kinase B),PCNA(proliferating cell nudear antigen),cleaved-caspase 3,E cadherin,and N-cadherin proteins using the Westem blot ***:LUAD tissues showed higher DARS2 expression compared to normal *** of DARS2 could be related to Tumor-Node-Metastasis(TNM)stage,high lymph node metastasis,and inferior ***2 silence decreased the proliferation,migration,and invasion abilities of LUAD *** addition,the DARS2 downregulation decreased the PCNA and N-cadherin expression and increased cleaved:caspase 3 and E cadherin expressions in LUAD cells,coupled with the inactivation of the PI3K/AKT signaling ***,DARS2 silence impaired the tumonigenicity of LUAD in ***,let:7b-5p could recognize DARS2 through a complementary ***,the increased let 7b 5p expression attenuated the promo oncogenic action of DARS2 during LUAD progression,which were inversely correlated to each other in the LUAD tssues Conclusion:In summary,let 7b-5p,downregulated DARS2 expression,regulating the progression of LUAD cells by the PI3K/AKT signaling pathway.

关键词： Lung adenocarcinoma Prognosis PI3K/AKT pathway Mitochondrial asparty-tRNA synthetase MicroRNAs

A stage-specific protein factor binding to a CACCC motif in both human β-globin gene promoter and 5'-HS2region

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cell Research 1994年第2期4卷 135-143页

作者： SUN TONG- yadi chen YULONG HU CHANGHONGDAI ruolan QIAN.(shanghai institute of cell biology, academia sinica,shanghai 200031- china） shanghai institute of cell biology Academia Sinica Shanghai China

The DNasel hypersensitive site 2 (HS2) of human β-globin locus control region (LCR) is required fOr the high level expression of human d-globin genes. In the present study, a stage-specific protein factor (LPF-β) was identified in the nuclear extract prepared from mouse fetal liver at d 18 of gestation, which could bind to the HS2 region of humanβ-globin LCRt We also found that the shift band of LPF-βfactor could be competed by humanβ-globin promoter. However, it couldn't be competed by human E-globin promoter or by human Aβ-globin promoter. Furthermore, our data demonstrated that the binding-sequence of LPF-d factor is 5'CACACCCTA 3',which is located at the HS2 region ofβ-LCR (from -10845 to -10853 bp) and humanβ-globin promoter (from -92 to -84 bp). We speculated that these regions containing the CACCC box in both the humallβ-globin promoter and HS2 might function as stage selector elements in the regulation of humanβd-globin switching and the LPF-βfactor might be a stage-specific protein factor involved in the regulation of humanβ-globin gene expression.

关键词： β-globin promoter HS2 of β-globin LCR trans-acting factor

Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

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Neural Regeneration Research 2024年第9期19卷 2027-2035页

作者： Lulu xue ruolan Du Ning Bi Qiuxia Xiao Yifei Sun Ruize Niu Yaxin Tan Li chen Jia Liu Tinghua Wang Liulin Xiong Transformation Research Laboratory The Affiliated Hospital of Zunyi Medical UniversityZunyiGuizhou ProvinceChina State Key Laboratory of Biotherapy Sichuan UniversityChengduSichuan ProvinceChina institute of Neurological Disease Translational Neuroscience CenterWest China HospitalSichuan UniversityChengduSichuan ProvinceChina Department of Animal Zoology Institute of NeuroscienceKunming Medical UniversityKunmingYunnan ProvinceChina Department of Anesthesiology The Affiliated Hospital of Zunyi Medical UniversityZunyiGuizhou ProvinceChina Department of Pediatrics the People’s Liberation Army Rocket Force Characteristic Medical CenterBeijingChina

Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic *** therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been ***,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been *** this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor *** chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model *** transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was *** further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering *** found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 ***,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic *** findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.

关键词： behavioral evaluations gene knockout human neuroblastoma cells(SH-SY5Y) human placental chorionic derived mesenchymal stem cells interleukin-3 neonatal hypoxic-ischemic encephalopathy nerve injury oxygen-glucose deprivation protein chip small interfering RNA

Decellularized extracellular matrix-based composite scaffolds for tissue engineering and regenerative medicine

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Regenerative Biomaterials 2024年第3期3卷 1-29页

作者： Peiyao xu Ranjith Kumar Kankala Shibin Wang Aizheng chen institute of Biomaterials and Tissue Engineering Huaqiao UniversityXiamenFujian 361021PR China Fujian Provincial Key Laboratory of Biochemical Technology(Huaqiao University) XiamenFujian 361021PR China

Despite the considerable advancements in fabricating polymeric-based scaffolds for tissue engineering,the clinical transformation of these scaffolds remained a big challenge because of the difficulty of simulating native organs/tissues'*** a kind of natural tissue-derived biomaterials,decellularized extracellular matrix(dECM)-based scaffolds have gained attention due to their unique biomimetic properties,providing a specific microenvironment suitable for promoting cell proliferation,migration,attachment and regulating *** medical applications of dECM-based scaffolds have addressed critical challenges,including poor mechanical strength and insufficient *** promoting the reconstruction of damaged tissues or organs,dif-ferent types of dECM-based composite platforms have been designed to mimic tissue microenvironment,including by integrating with natural polymer or/and syntenic polymer or adding bioactive *** this review,we summarized the research progress of dECM-based composite scaffolds in regenerative medicine,highlighting the critical challenges and future perspectives related to the medical application of these composite materials。

关键词： decellularized extracellular matrix polymer bioactive factors composites tissue engineering

Robust asymmetric Cherenkov radiation in tilted anisotropic medium

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Science china(Physics,Mechanics & Astronomy) 2024年第1期67卷 46-51页

作者： Shuwen xue Yadong xu Linkang Han Zhi Ning chen Qiaoliang Bao Shan Zhu Huanyang chen institute of Electromagnetics and Acoustics and Department of Physics College of Physical Science and TechnologyJiujiang Research InstituteXiamen UniversityXiamen 361005China School of Physical Science and Technology Institute of Theoretical and Applied PhysicsSoochow UniversitySuzhou 215006China Department of Electrical and Computer Engineering National University of SingaporeSingapore 8117583Singapore institute of Energy Materials Science(IEMS) University of Shanghai for Science and TechnologyShanghai 200093China

Cherenkov radiation(CR)is available for a wide variety of terahertz(THz)radiation sources,but its efficiency is deeply affected by intrinsic *** find that if the tilted angle(α)of anisotropic material and radiation angle(θ)meet the condition ofθ+α=π/2,the intensity of radiation fields for the charged particle bunch(CPB)moving from left to right cannot be influenced by intrinsic losses,which means long-distance radiation can be ***,we observe an asymmetric CR when the CPB moves from the opposite *** addition,we select natural van der Waals(vd W)materialα-MoO3as an example,further confirming that the radiation field can reach the far field and the asymmetric CR radiation can also be *** wonderful properties with long-distance radiation will extend the application of CR to a certain extent for future design and fabrication.

关键词： asymmetric Cherenkov radiation intrinsic losses long-distance radiation