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Unveiling the role of hypoxia-inducible factor 2alpha in osteoporosis:Implications for bone health

World Journal of Stem Cells 2024年第4期16卷 389-409页

作者： Ling-Ling Wang Zhan-Jin Lu shun-Kui Luo yun Li Zhe Yang Hong-yun Lu Department of Gerontology The Fifth Affiliated Hospital of Sun Yat-sen UniversityZhuhai 519000Guangdong ProvinceChina Department of Endocrinology and Metabolism The Fifth Affiliated Hospital of Sun Yat-sen UniversityZhuhai 519000Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Biomedical Imaging The Fifth Affiliated Hospital of Sun Yat-sen UniversityZhuhai 519000Guangdong ProvinceChina Department of Endocrinology and Metabolism Zhuhai People’s Hospital(Zhuhai Clinical Medical College of Jinan Universitythe First Hospital Affiliated with Medical College of Macao University of Science and Technology)Zhuhai 519000Guangdong ProvinceChina

BACKGROUND Osteoporosis(OP)has become a major public health problem worldwide.Most OP treatments are based on the inhibition of bone resorption,and it is necessary to identify additional treatments aimed at enhancing osteogenesis.In the bone marrow(BM)niche,bone mesenchymal stem cells(BMSCs)are exposed to a hypoxic environment.Recently,a few studies have demonstrated that hypoxiainducible factor 2alpha(HIF-2α)is involved in BMSC osteogenic differentiation,but the molecular mechanism involved has not been determined.AIM To investigate the effect of HIF-2αon the osteogenic and adipogenic differentiation of BMSCs and the hematopoietic function of hematopoietic stem cells(HSCs)in the BM niche on the progression of OP.METHODS Mice with BMSC-specific HIF-2αknockout(Prx1-Cre;Hif-2αfl/fl mice)were used for in vivo experiments.Bone quantification was performed on mice of two genotypes with three interventions:Bilateral ovariectomy,semilethal irradiation,and dexamethasone treatment.Moreover,the hematopoietic function of HSCs in the BM niche was compared between the two mouse genotypes.In vitro,the HIF-2αagonist roxadustat and the HIF-2αinhibitor PT2399 were used to investigate the function of HIF-2αin BMSC osteogenic and adipogenic differentiation.Finally,we investigated the effect of HIF-2αon BMSCs via treatment with the mechanistic target of rapamycin(mTOR)agonist MHY1485 and the mTOR inhibitor rapamycin.RESULTS The quantitative index determined by microcomputed tomography indicated that the femoral bone density of Prx1-Cre;Hif-2αfl/fl mice was lower than that of Hif-2αfl/fl mice under the three intervention conditions.In vitro,Hif-2αfl/fl mouse BMSCs were cultured and treated with the HIF-2αagonist roxadustat,and after 7 d of BMSC adipogenic differentiation,the oil red O staining intensity and mRNA expression levels of adipogenesis-related genes in BMSCs treated with roxadustat were decreased;in addition,after 14 d of osteogenic differentiation,BMSCs treated with roxadustat exhibited increased expression of osteogenesis

关键词： Hypoxia-inducible factor-2α Bone marrow niche Bone mesenchymal stem cells Osteoporosis Osteogenic/adipogenic differentiation Mechanistic target of rapamycin signaling pathway

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Left atrial appendage occluder detachment treated with transthoracic ultrasound combined with digital subtraction angiography guided catcher:A case report

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World Journal of Clinical Cases 2024年第6期12卷 1157-1162页

作者： Kai yu yun-Hua Mei Department of Ultrasound Wuhan Dongxihu District People's HospitaWuhan 430400Hubei ProvinceChina Department of Infectious Diseases Wuhan Dongxihu District People's HospitalWuhan 430400Hubei ProvinceChina

BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.

关键词： Left atrial appendage occluder Detachment Ultrasound combined with digital subtraction angiography Interventional operation Successfully captured Case report

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The effect of Ti and Zr content on the structure,mechanics and energy-release characteristics of Ti—Zr—Ta alloys

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Defence Technology（防务技术） 2024年第1期31卷 343-350页

作者： Jia-yu Meng Jing-zhi He Bin Zhang Jin Chen shun Li Dun Niu yu Tang Xi’an Modern Chemistry Research Institute Xi'an710065China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China

Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage characteristics.In this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-Ta alloys with good casting performance were studied.The microstructure of the Ti_(x)ZrTa alloys gradually change from BCC+HCP to single BCC structure with the increase of Ti.While the Ti_(2)Zr_(y)Ta alloys was still uniform and single BCC structure with the increase of Zr.The evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-Ta alloys.The synergistic effect of dual phase structure increases the fracture strain of Ti_(x)ZrTa(x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)ZrTa(x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation movement.And as Zr content increases,the fracture strain of Ti_(2)Zr_(y)Ta alloys decrease,then the oxidation reaction rate and fragmentation degree gradually increase.The higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)ZrTa alloys with low Ti content and Ti_(2)Zr_(y)Ta alloys with high Zr content.

关键词： Energetic structural materials Ti-Zr-Ta Multi-element alloy Energy release characteristics

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Melittin analog p5RHH enhances recombinant adeno-associated virus transduction efficiency

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Journal of Integrative Medicine 2024年第1期22卷 72-82页

作者： Jing-shun Meng yun He Heng-bin Yang Li-ping Zhou Si-yuan Wang Xi-lin Feng Omar Yahya Al-shargi Xiao-min yu Li-qing Zhu Chang-quan Ling Shanghai University of Traditional Chinese Medicine Shanghai 201203China Oncology Department of Traditional Chinese Medicine Changhai HospitalNaval Medical UniversityShanghai 200433China Faculty of Traditional Chinese Medicine Naval Medical UniversityShanghai 200043China State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology(Ministry of Education) School of Life SciencesZhongshan HospitalFudan UniversityShanghai 200438China Yantai Fuheng Biological Technology Co. Ltd.YantaiShandong Province 264006China. Department of Clinical Laboratory the First Affiliated Hospital of Wenzhou Medical UniversityWenzhou 325000Zhejiang ProvinceChina

Objective Melittin and its derivatives have been characterized to establish effective gene delivery systems.Their capability of facilitating endosomal release enhances the nanoparticles-based gene delivery.Nevertheless,little investigation has been conducted to explore its potential application in the context of viral vectors.Methods Various melittin-derived peptides were inserted into the loop VIII of the capsid proteins of recombinant adeno-associated virus vectors.These vectors carrying either gfp or fluc genes were subjected to qPCR assays and transduction assays of HEK293T cells to investigate the efficiency of vector production and gene delivery.In addition,the ability of a specific p5RHH-rAAV vector to deliver genes was examined through in vitro transduction of different cultured cells and in vivo tail vein administration to C57BL/6 mice.Finally,the intricate details of the vector-mediated transduction mechanisms were revealed by specific pharmacological inhibitors of every stage of the rAAV2 intracellular life cycle.Results A total of 76 melittin-related peptides were compiled from existing literature.Among them,cMA2,Melt13,p5RHH and aAR3 were found to significantly enhance the gene delivery efficiency of rAAV2 vectors.The p5RHH-rAAV2 vectors efficiently transduced not only rAAV-potent cell lines but also cell lines previously considered resistant to rAAV.Mechanistically,bafilomycin A1,a vacuolar endosome acidification inhibitor,completely inhibited the transgene expression mediated by the p5RHH-rAAV2 vectors.Most importantly,p5RHH-rAAV8 vectors also demonstrated increased hepatic transduction in vivo in C57BL/6 mice.Conclusion The incorporation of melittin analogues into the rAAV capsids results in a significant improvement in rAAV-mediated transgene expression.While further modifications remain an area of interest,our studies have substantially broadened the pharmacological prospects of melittin in the context of viral vector-mediated gene delivery.

关键词： Melittin Recombinant adeno-associated virus Capsid engineering Transduction efficiency

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Understanding the Thermal Impedance of Silicone Rubber/Hexagonal Boron Nitride Composites as Thermal Interface Materials

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Chinese Journal of Polymer Science 2024年第3期42卷 352-363,I0008页

作者： yuan Ji Shi-Da Han Hong Wu Shao-yun Guo Feng-shun Zhang Jian-Hui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials Hexagonal boron nitride Thermal impedance Surfaces

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Capture Efficiency Analysis in the Circular Restricted Three-body Problem

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Research in Astronomy and Astrophysics 2024年第5期24卷 198-210页

作者： yu-Xuan Miao Xi-yun Hou Department of Astronomy and Space Science Nanjing UniversityNanjing 210023China Institute of Space Environment and Astrodynamics Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducationNanjing 210023China

Temporary capture efficiency is studied in the framework of the circular restricted three-body problem in two steps.First, a non-uniform distribution of test particles around the secondary's orbit is obtained by fully accounting the secondary's gravitational influence. Second, the capture efficiency is computed based on the non-uniform distribution. Several factors influencing the result are discussed. By studying the capture efficiency in the circular restricted three-body problem of different mass ratios, a power-law relation between the capture efficiency(p) and the mass ratio(μ) is established, which is given by p ≈ 0.27 × μ^(0.53), within the range of 3.0035 ×10^(-6)≤ μ ≤ 3.0034 × 10^(-5). Taking the Sun–Earth system as an example, the influence from the orbit eccentricity of the secondary on the non-uniform distribution and the capture efficiency is studied. Our studies find that the secondary's orbit eccentricity has a negative influence on the capture efficiency.

关键词： methods numerical-celestial mechanics-planets and satellites dynamical evolution and stability

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Strain engineering of Pt-based electrocatalysts for oxygen reaction reduction

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Frontiers in Energy 2024年第2期18卷 241-262页

作者： Zeyu WANG Yanru LIU shun CHEN yun ZHENG Xiaogang FU Yan ZHANG Wanglei WANG State Key Laboratory of Solidification Processing Atomic Control and Catalysis Engineering LaboratorySchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration National Clinical Research Center for Oral DiseasesShaanxi Key Laboratory of StomatologyDepartment of Dental MaterialsSchool of StomatologyThe Fourth Military Medical UniversityXi’an 710032China Institute of New Energy Materials and Engineering School of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China Key Laboratory of Marine Chemistry Theory and Technology(Ministry of Education) College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao 266100China

Proton exchange membrane fuel cells(PEMFCs)are playing irreplaceable roles in the construction of the future sustainable energy system.However,the insufficient performance of platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)hinders the overall efficiency of PEMFCs.Engineering the surface strain of catalysts is considered an effective way to tune their electronic structures and therefore optimize catalytic behavior.In this paper,insights into strain engineering for improving Pt-based catalysts toward ORR are elaborated in detail.First,recent advances in understanding the strain effects on ORR catalysts are comprehensively discussed.Then,strain engineering methodologies for adjusting Ptbased catalysts are comprehensively discussed.Finally,further information on the various challenges and potential prospects for strain modulation of Pt-based catalysts is provided.

关键词： strain engineering Pt-based catalysts oxygen reduction reaction(ORR) catalytic performance proton exchange membrane fuel cells(PEMFCs)

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Analysis of mechanical strengths of extreme line casing joint considering geometric, material, and contact nonlinearities

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Petroleum Science 2024年第3期21卷 1992-2004页

作者： Ji-yun Zhang Chi Peng Jian-Hong Fu Quan Cao yu Su Jian-yun Pang Zi-Qiang yu Petroleum Engineering School Southwest Petroleum University Engineering Technology Research Institute of CNPC Southwest Oil and Gas Field Company

To address the challenges associated with difficult casing running, limited annular space, and poor cementing quality in the completion of ultra-deep wells, the extreme line casing offers an effective solution over conventional casings. However, due to its smaller size, the joint strength of extreme line casing is reduced, which may cause failure when running in the hole. To address this issue, this study focuses on the CST-ZT Φ139.7 mm × 7.72 mm extreme line casing and employs the elastic-plastic mechanics to establish a comprehensive analysis of the casing joint, taking into account the influence of geometric and material nonlinearities. A finite element model is developed to analyze the forces and deformations of the extreme line casing joint under axial tension and external collapse load. The model investigates the stress distribution of each thread tooth subjected to various tensile forces and external pressures. Additionally, the tensile strength and crushing strength of the extreme line casing joint are determined through both analytical and experimental approaches. The findings reveal that, under axial tensile load, the bearing surface of each thread tooth experiences uneven stress, with relatively high equivalent stress at the root of each thread tooth. The end thread teeth are valuable spots for failure. It is observed that the critical fracture axial load of thread decreases linearly with the increase of thread tooth sequence. Under external pressure, the circumferential stress is highest at the small end of the external thread, leading to yield deformation. The tensile strength of the joint obtained from the finite element model exhibits a relative error of less than 7% compared to the analytical and experimental values,proving the reliability of the finite element model. The tensile strength of the joint is 3091.9 k N.Moreover, in terms of anti-collapse capability, the joints demonstrate higher resistance to collapse compared to the casing body, which is consistent with the test results where the pip

关键词： Extreme line casing Elastic-plastic mechanics Finite element analysis Tensile strength Collapse strength

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Effect of initial ammonium concentration on a one-stage partial nitrification/anammox biofilm system:Nitrogen removal performance and the microbial community

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Journal of Environmental Sciences 2024年第9期143卷 176-188页

作者： Mengyu Zhou yun Han Yang Zhuo Fen yu Gaoyuan Hu Dangcong Peng School of Municipal and Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Shaanxi Key Laboratory of Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key Laboratory of Northwest Water Resource Environment and EcologyMOEXi’an University of Architecture and TechnologyXi’an 710055China

One-stage partial nitrification coupled with anammox(PN/A)technology effectively reduces the energy consumption of a biological nitrogen removal system.Inhibiting nitrite-oxidizing bacteria(NOB)is essential for this technology to maintain efficient nitrogen removal performance.Initial ammonium concentration(IAC)affects the degree of inhibited NOB.In this study,the effect of the IAC on a PN/A biofilm was investigated in a moving bed biofilm reactor.The results showed that nitrogen removal efficiency decreased from 82.49%±1.90%to 64.57%±3.96%after the IAC was reduced from 60 to 20 mg N/L,while the nitrate production ratio increased from 13.87%±0.90%to 26.50%±3.76%.NOB activity increased to1,133.86 mg N/m^(2)/day after the IAC decreased,approximately 4-fold,indicating that the IAC plays an important inhibitory role in NOB.The rate-limiting step in the mature biofilm of the PN/A system is the nitritation process and is not shifted by the IAC.The analysis of the microbial community structure in the biofilm indicates that the IAC was the dominant factor in changes in community structure.Ca.Brocadia and Ca.Jettenia were the main anammox bacteria,and Nitrosomonas and Nitrospira were the main AOB and NOB,respectively.IAC did not affect the difference in growth between Ca.Brocadia and Ca.Jettenia.Thus,modulating the IAC promoted the PN/A process with efficient nitrogen removal performance at medium to low ammonium concentrations.

关键词： Biological nitrogen removal Partial nitrification Anammox Ammonium concentration Biofilm

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Regeneration of the heart:f rom molecular mechanisms to clinical therapeutics

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Military Medical Research 2024年第1期11卷 80-97页

作者： Qian-yun Guo Jia-Qi Yang Xun-Xun Feng yu-Jie Zhou Beijing Key Laboratory of Precision Medicine of Coronary Atherosclerotic Disease Beijing Institute of Heart Lung and Blood Vessel DiseaseClinical Center for Coronary Heart DiseaseDepartment of CardiologyBeijing Anzhen HospitalCapital Medical UniversityBeijing 100029China

Heart injury such as myocardial infarction leads to cardiomyocyte loss,fibrotic tissue deposition,and scar formation.These changes reduce cardiac contractility,resulting in heart failure,which causes a huge public health burden.Military personnel,compared with civilians,is exposed to more stress,a risk factor for heart diseases,making cardiovascular health management and treatment innovation an important topic for military medicine.So far,medical intervention can slow down cardiovascular disease progression,but not yet induce heart regeneration.In the past decades,studies have focused on mechanisms underlying the regenerative capability of the heart and applicable approaches to reverse heart injury.Insights have emerged from studies in animal models and early clinical trials.Clinical interventions show the potential to reduce scar formation and enhance cardiomyocyte proliferation that counteracts the pathogenesis of heart disease.In this review,we discuss the signaling events controlling the regeneration of heart tissue and summarize current therapeutic approaches to promote heart regeneration after injury.

关键词： Heart regeneration Cardiac disease Therapeutics Signaling mechanisms

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