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Structural transformation and magnetic properties of Sm-Fe alloys with V doping

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Rare Metals 2022年第7期41卷 2349-2352页

作者： Yong-Jun Mao jin-ling jin Jia-Jun Xie Yang Luo Kuo-She Li Wen-Long Yan Dun-Bo Yu Hong-Wei Li National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous MetalsBeijing 100088China Grirem Advanced Materials Co.Ltd. Beijing 100088China

A systematical investigation was carried out on structure and magnetic properties in SmFe_(9-x)V_(x)(x=0.4,0.8,1.2)compounds prepared by a single-roller quenching method.The high cool-down rate leads to metastable TbCu_(7) phase in the parent compound,which gradually transforms into equilibrium ThMn_(12) structure with V-doping content increasing.The Curie temperature increases from 470 to 590 K with V doping,which is consistent with the phase transformation.Surprisingly,simultaneous increase in both coercivity and remanence is resulted by V doping,reaching the highest value of 685 kA·m^(-1)and 44.8×10^(-3)A·m^(2)·g^(-1)in x=1.2 compound,respectively.This phenomenon can be explained by the combination of phase transformation and intergranular exchange coupling throughδM-H plots.

关键词： Phase transformation Magnetic properties Exchange coupling Element doping ThMn12-type phase

Magnetic properties optimization of nanocomposite Nd_9Fe_(85)B_6 magnets by controlling microstructure of as-quenched ribbons

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Rare Metals 2014年第3期33卷 299-303页

作者： Yu-Chao Liu Hong-Wei Li Kuo-She Li Dun-Bo Yu jin-ling jin Yang Luo Liang Sun Ning-Tao Quan National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals

To optimize the magnetic properties of nanocomposite Nd9Fe85B6 magnets, the as-quenched ribbons with different microstructures were prepared at six wheel velocities from 10 to 30 m s^-1through rapid quenching,followed by a series of annealing treatments at 550-800 °C for 5-10 min. It is found that both the large initial grains at low cooling rate and high content of amorphous phase at high cooling rate cause a-Fe grains coarsening, which leads to a decline in the strength of exchange coupling interaction and the deterioration of magnetic properties. In order to optimize the magnetic properties, the as-quenched ribbons should be chosen with relatively small initial grains as well as a small amount of amorphous phase. For nanocomposite Nd9Fe85B6 materials, the optimized magnetic properties of Hcj= 446 kA m^-1, Br= 0.86 T,（BH）max=80 kJ m^-3are obtained for ribbons prepared at 18 m s-1after annealing at 620 °C for 5 min.

关键词： Nanocomposite Rapid quenching Microstructure Grain sizes

Constrained Multi-Objective Optimization With Deep Reinforcement Learning Assisted Operator Selection

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 919-931页

作者： Fei Ming Wenyin Gong ling Wang Yaochu jin the School of Computer Science China University of GeosciencesWuhan 430074China the Department of Automation Tsinghua UniversityBeijing 100084China the Faculty of Technology Bielefeld UniversityNorth Rhine-Westphalia33619 BielefeldGermany

Solving constrained multi-objective optimization problems with evolutionary algorithms has attracted considerable attention.Various constrained multi-objective optimization evolutionary algorithms(CMOEAs)have been developed with the use of different algorithmic strategies,evolutionary operators,and constraint-handling techniques.The performance of CMOEAs may be heavily dependent on the operators used,however,it is usually difficult to select suitable operators for the problem at hand.Hence,improving operator selection is promising and necessary for CMOEAs.This work proposes an online operator selection framework assisted by Deep Reinforcement Learning.The dynamics of the population,including convergence,diversity,and feasibility,are regarded as the state;the candidate operators are considered as actions;and the improvement of the population state is treated as the reward.By using a Q-network to learn a policy to estimate the Q-values of all actions,the proposed approach can adaptively select an operator that maximizes the improvement of the population according to the current state and thereby improve the algorithmic performance.The framework is embedded into four popular CMOEAs and assessed on 42 benchmark problems.The experimental results reveal that the proposed Deep Reinforcement Learning-assisted operator selection significantly improves the performance of these CMOEAs and the resulting algorithm obtains better versatility compared to nine state-of-the-art CMOEAs.

关键词： Constrained multi-objective optimization deep Qlearning deep reinforcement learning(DRL) evolutionary algorithms evolutionary operator selection

Thoracic spine infection caused by Pseudomonas fluorescens:A case report and review of literature

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World Journal of Clinical Cases 2024年第12期12卷 2099-2108页

作者： Liang Li Bao-Hua Zhang jin-Feng Cao Li-jin Zhang ling-ling Guo Department of Traditional Chinese Medicine Zibo Central HospitalZibo 255000Shandong ProvinceChina Department of Pathology Zibo Central HospitalZibo 255000Shandong ProvinceChina Department of Medical Imaging Zibo Central HospitalZibo 255000Shandong ProvinceChina

BACKGROUND The clinical incidence of spinal infection is gradually increasing,and its onset is insidious,easily leading to missed diagnosis and misdiagnosis,which may lead to serious complications such as nervous system dysfunction,spinal instability and/or deformity,and cause a huge burden on society and families.Early identification of the causative agent and precision medicine will greatly reduce the suffering of patients.At present,the main pathogenic bacteria that cause spinal infection are Staphylococcus aureus,Streptococcus,Pneumococcus,Escherichia coli,and Klebsiella.There are no reports of spinal infection caused by Pseudomonas fluorescens.CASE SUMMARY We report a 32-year-old female patient with spinal infection.She presented with flank pain,initially thought to be bone metastases or bone tuberculosis,and had a family background of tumors.Her clinical features and changes in imaging and laboratory tests led to the suspicion of thoracic spine infection.Histopathology of the lesion showed inflammation,tissue culture of the lesion was negative several times,and the possible pathogen-Pseudomonas fluorescens was found after gene sequencing of the lesion.The patient recovered completely after a full course of antibiotic treatment.CONCLUSION This report increases the range of pathogens involved in spinal infections,highlights the unique advantages of gene sequencing technology in difficult-todiagnose diseases,and validates conservative treatment with a full course of antibiotics for spinal infections without complications.

关键词： Thoracic spine infection Pseudomonas fluorescens Spinal infection Case report

Novel milestones for early esophageal carcinoma:From bench to bed

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1104-1118页

作者： Ji-Han Qi Shi-ling Huang Shi-Zhu jin Department of Gastroenterology and Hepatology The Second Affiliated Hospital of Harbin Medical UniversityHarbin 150086Heilongjiang ProvinceChina

Esophageal cancer(EC)is the seventh most common cancer worldwide,and esophageal squamous cell carcinoma(ESCC)accounts for the majority of cases of EC.To effectively diagnose and treat ESCC and improve patient prognosis,timely diagnosis in the initial phase of the illness is necessary.This article offers a detailed summary of the latest advancements and emerging technologies in the timely identification of ECs.Molecular biology and epigenetics approaches involve the use of molecular mechanisms combined with fluorescence quanti-tative polymerase chain reaction(qPCR),high-throughput sequencing technology(next-generation sequencing),and digital PCR technology to study endogenous or exogenous biomolecular changes in the human body and provide a decision-making basis for the diagnosis,treatment,and prognosis of diseases.The invest-igation of the microbiome is a swiftly progressing area in human cancer research,and microorganisms with complex functions are potential components of the tumor microenvironment.The intratumoral microbiota was also found to be connected to tumor progression.The application of endoscopy as a crucial technique for the early identification of ESCC has been essential,and with ongoing advancements in technology,endoscopy has continuously improved.With the advancement of artificial intelligence(AI)technology,the utilization of AI in the detection of gastrointestinal tumors has become increasingly prevalent.The implementation of AI can effectively resolve the discrepancies among observers,improve the detection rate,assist in predicting the depth of invasion and differentiation status,guide the pericancerous margins,and aid in a more accurate diagnosis of ESCC.

关键词： Early esophageal squamous cell carcinoma Epidemiology and risk factors Molecular biology Epigenetic Microbiology Endoscopy and artificial intelligence

Effect of Sonic hedgehog gene-modified bone marrow mesenchymal stem cells on graft-induced retinal gliosis and retinal ganglion cells survival in diabetic mice

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 34-41页

作者： Tong Wang Hai-Chun Li jin Ma Xi-ling Yu State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhou 510060Guangdong ProvinceChina

AIM:To investigate the effects of Sonic hedgehog(Shh)gene-modified bone marrow mesenchymal stem cells(MSCs)on graft-induced retinal gliosis and retinal ganglion cells(RGCs)survival in diabetic mice.METHODS:Bone marrow-derived MSCs were genetically modified with the Shh gene to generate a stably transfected cell line of Shh-modified MSCs(MSC-Shh).Intravitreal injections of MSC-Shh and green fluorescent protein-modified MSCs(MSC-Gfp;control)were administered in diabetic mice.After 4wk,the effects of MSC-Shh on retinal gliosis were evaluated using fundus photography,and markers of gliosis were examined by immunofluorescence and Western blotting.The neurotrophic factors expression and RGCs survival in the host retina were evaluated using Western blotting and immunofluorescence.The mechanisms underlying the effects of MSC-Shh was investigated.RESULTS:A significant reduction of proliferative vitreoretinopathy(PVR)was observed after intravitreal injection of MSC-Shh compared to MSC-Gfp.Significant downregulation of glial fibrillary acidic protein(GFAP)was demonstrated in the host retina after MSC-Shh administration compared to MSC-Gfp.The extracellular signal-regulated kinase 1/2(ERK1/2),protein kinase B(AKT)and phosphatidylin-ositol-3-kinase(PI3K)pathways were significantly downregulated after MSC-Shh administration compared to MSC-Gfp.Brain-derived neurotrophic factor(BDNF)and ciliary neurotrophic factor(CNTF)levels were significantly increased in the host retina,and RGCs loss was significantly prevented after MSC-Shh administration.CONCLUSION:MSC-Shh administration reduces graft-induced reactive gliosis following intravitreal injection in diabetic mice.The ERK1/2,AKT and PI3K pathways are involved in this process.MSC-Shh also increases the levels of neurotrophic factors in the host retina and promoted RGCs survival in diabetic mice.

关键词： mesenchymal stem cells Sonic hedgehog signaling reactive gliosis diabetic retinopathy retinal ganglion cells

Patient-derived induced pluripotent stem cells with a MERTK mutation exhibit cell junction abnormalities and aberrant cellular differentiation potential

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World Journal of Stem Cells 2024年第5期16卷 512-524页

作者： Hang Zhang ling-Zi Wu Zhen-Yu Liu Zi-Bing jin Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing 100730China

BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease mechanisms.However,iPSCs carrying specific mutations may limit their clinical applications due to certain inherent characteristics.AIM To investigate the impact of MERTK mutations on hiPSCs and determine whether hiPSC-derived extracellular vesicles(EVs)influence anomalous cell junction and differentiation potential.METHODS We employed a non-integrating reprogramming technique to generate peripheral blood-derived hiPSCs with and hiPSCs without a MERTK mutation.Chromo-somal karyotype analysis,flow cytometry,and immunofluorescent staining were utilized for hiPSC identification.Transcriptomics and proteomics were employed to elucidate the expression patterns associated with cell junction abnormalities and cellular differentiation potential.Additionally,EVs were isolated from the supernatant,and their RNA and protein cargos were examined to investigate the involvement of hiPSC-derived EVs in stem cell junction and differentiation.RESULTS The generated hiPSCs,both with and without a MERTK mutation,exhibited normal karyotype and expressed pluripotency markers;however,hiPSCs with a MERTK mutation demonstrated anomalous adhesion capability and differentiation potential,as confirmed by transcriptomic and proteomic profiling.Furthermore,hiPSC-derived EVs were involved in various biological processes,including cell junction and differentiation.CONCLUSION HiPSCs with a MERTK mutation displayed altered junction characteristics and aberrant differentiation potential.Furthermore,hiPSC-derived EVs played a regulatory role in various biological processes,including cell junction and differentiation.

关键词： Cell junction Cellular differentiation Extracellular vesicle Human induced pluripotent stem cells Transcriptomics Proteomics

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

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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

Unmanned Ship Identification Based on Improved YOLOv8s Algorithm

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Computers, Materials & Continua 2024年第3期78卷 3071-3088页

作者： Chun-Ming Wu jin Lei Wu-Kai Liu Mei-ling Ren ling-Li Ran Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology School of Electrical EngineeringNortheast Electric Power UniversityJilin132012China School of Biomedical Engineering Taiyuan University of TechnologyTaiyuan030600China

Aiming at defects such as low contrast in infrared ship images,uneven distribution of ship size,and lack of texture details,which will lead to unmanned ship leakage misdetection and slow detection,this paper proposes an infrared ship detection model based on the improved YOLOv8 algorithm(R_YOLO).The algorithm incorporates the Efficient Multi-Scale Attention mechanism(EMA),the efficient Reparameterized Generalized-feature extraction module(CSPStage),the small target detection header,the Repulsion Loss function,and the context aggregation block(CABlock),which are designed to improve the model’s ability to detect targets at multiple scales and the speed of model inference.The algorithm is validated in detail on two vessel datasets.The comprehensive experimental results demonstrate that,in the infrared dataset,the YOLOv8s algorithm exhibits improvements in various performance metrics.Specifically,compared to the baseline algorithm,there is a 3.1%increase in mean average precision at a threshold of 0.5(mAP(0.5)),a 5.4%increase in recall rate,and a 2.2%increase in mAP(0.5:0.95).Simultaneously,while less than 5 times parameters,the mAP(0.5)and frames per second(FPS)exhibit an increase of 1.7%and more than 3 times,respectively,compared to the CAA_YOLO algorithm.Finally,the evaluation indexes on the visible light data set have shown an average improvement of 4.5%.

关键词： Unmanned ships R_YOLO EMA CSPStage YOLOv8s