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Extracellular vesicles derived from mesenchymal stem cells mediate extracellular matrix remodeling in osteoarthritis through the transport of microRNA-29a

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World Journal of Stem Cells 2024年第2期16卷 191-206页

作者： Fan Yang Wan-Qi Xiong chen-zhi li Ming-Jian Wu Xiu-zhi Zhang Chun-Xiao Ran Zhen-Hao li Yan Cui Bao-Yi liu De-Wei Zhao Department of Orthopedics Affiliated Zhongshan Hospital of Dalian UniversityDalian 116001Liaoning ProvinceChina

BACKGROUND Knee osteoarthritis(KOA)is a common orthopedic condition with an uncertain etiology,possibly involving genetics and *** like changes in chondrocyte microenvironment,oxidative stress,inflammation,and immune responses affect KOA ***-stage treatment options primarily target symptom *** stem cells(MSCs)show promise for treatment,despite *** research highlights microRNAs(miRNAs)within MSC-released extracellular vesicles that can potentially promote cartilage regeneration and hinder KOA *** suggests exosomes(Exos)as a promising avenue for future *** these findings emphasize the need for effective KOA progression management,further safety and efficacy validation for Exos is *** To explore miR-29a’s role in KOA,we’ll create miR-29a-loaded vesicles,testing for early treatment in rat *** Extraction of bone marrow MSC-derived extracellular vesicles,preparation of engineered vesicles loaded with miR-29a using ultrasonication,and identification using quantitative reverse transcription polymerase chain reaction;after establi-shing a rat model of KOA,rats were randomly divided into three groups:Blank control group injected with saline,normal extracellular vesicle group injected with normal extracellular vesicle suspension,and engineered extrace-llular vesicle group injected with engineered extracellular vesicle *** three groups evaluation,histological detection,and immunohistochemical detection to compare and evaluate the progress of various forms of *** General behavioral observation results showed that the extracellular vesicle group and engineered extracellular vesicle group had better performance in all four indicators of pain,gait,joint mobility,and swelling compared to the blank control ***,the engineered extracellular vesicle group had better pain relief at 4 wk and better knee joint mobility at 8 wk compared to the nor

关键词： Exosomes Osteoarthritis Mesenchymal stem cells MicroRNA-29a Intra-articular injection

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重型破冰船适用结构规范对比分析

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船海工程 2024年第3期53卷 43-49页

作者：林一陈励志中国核能电力股份有限公司北京100045

围绕现行的FSICR、RMRS和IACS三大冰区航行船舶规范,对船级符号、船体分区、总纵强度、低温材料等要求展开讨论。以重型破冰船为对象,对结构设计中的冰载荷计算,以及冰级、排水量、骨架形式、肋骨间距等设计参数的影响进行比较分析,为... 详细信息

围绕现行的FSICR、RMRS和IACS三大冰区航行船舶规范,对船级符号、船体分区、总纵强度、低温材料等要求展开讨论。以重型破冰船为对象,对结构设计中的冰载荷计算,以及冰级、排水量、骨架形式、肋骨间距等设计参数的影响进行比较分析,为此类船型的结构设计提供技术参考。

关键词：破冰船规范研究冰级冰载荷

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基于改进YOLOv5的潜艇目标检测算法

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激光与红外 2024年第6期54卷 971-979页

作者：梅礼坤陈智利西安工业大学光电工程学院陕西西安710021

为了解决传统潜艇目标检测缺乏对复杂背景和噪声的鲁棒性、对光照变化和视角变化敏感、难以处理大规模数据集等问题,提出了一种基于改进YOLOv5潜艇目标检测器。通过C3_Transformer结构,有效提升了特征的全局上下文建模能力和长距离依赖... 详细信息

为了解决传统潜艇目标检测缺乏对复杂背景和噪声的鲁棒性、对光照变化和视角变化敏感、难以处理大规模数据集等问题,提出了一种基于改进YOLOv5潜艇目标检测器。通过C3_Transformer结构,有效提升了特征的全局上下文建模能力和长距离依赖性捕捉能力;通过simOTA解决anchorbased算法中正负样本不平衡问题,增强模型对小目标和困难样本的学习能力;利用decoupledhead的思想解决分类和位置预测任务的互斥性问题,提高检测精度和鲁棒性。实验结果表明:相较于原始YOLOv5,改进后的模型Precision、Recall、mAP0.5、mAP0.5:0.95分别提高了2.8%、10.9%、3.8%、14.7%,这表明改进后的模型在潜艇目标检测的准确性、召回率以及在不同置信度阈值下的平均准确率等方面取得了明显的进步,同时在实际检测任务中改进后的模型有效解决了“漏检”、“误检”的问题。

关键词：上下文样本不平衡互斥性最优传输问题

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A new concept and preliminary study of variable hypersonic inlet with fixed geometry based on shockwave control

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Science China(Technological Sciences) 2007年第5期50卷 644-657页

作者： TAN HuiJun chen zhi li GuangSheng College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

The inlet plays a significant role in the hypersonic airbreathing propulsion. A fixed-geometry inlet is troubled by low air-capture ratio and large additional drag while operating below the design Mach number. Whereas a variable-geometry inlet can maximize performance, but adds weight and complexity to the propulsion system. Based on a fluidic shock shape control technique, this paper proposes a new concept of variable hypersonic inlet with fixed geometry, gives the realization scheme, and conducts a preliminary validation. The results show that the control of the external shock system and the effective throat area can be achieved by the self-provided high pressure fluid of the inlet. For an inlet with an operating Mach-number region of 4 to 6, the shock-on-lip condition can be maintained from Mach 5 to Mach 6 with the maximum expense of 1.8% secondary flow ratio, result- ing in 20% extra captured mass flow and 8% less forebody drag at low Mach num- bers compared with conventional fixed-geometry inlets. Thus, the performance enhancement by using the proposed variable inlet can substantially benefit the acceleration process of hypersonic vehicles at low Mach numbers.

关键词： hypersonic inlets, variable inlets, shock shape control technique

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Effects of estrogen on collagen gel contraction by human retinal glial cells

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Chinese Medical Journal 2012年第22期125卷 4098-4103页

作者： QIU Qing-hua chen zhi-Yi YIN li-li ZHENG zhi WU Xing-wei Shanghai Jiao Tong Univ Dept Ophthalmol Peoples Hosp 1 Shanghai 200080 Peoples R China Shanghai Heping Eye Hosp Shanghai 200437 Peoples R China

Background There are definite gender differences in patients with macular holes. Menopausal women over 50 years are most affected. We aimed to observe the effect of estrogen on collagen gel contraction by cultured human retinal glial cells. It is speculated that estrogen could strengthen the tensile stress of the macula by maintaining the correct morphology and contraction. Methods Estrogen was used to determine its effects on collagen gel contraction, and its function was measured using morphological changes in cells. Human retinal glial cells were cultured in collagen solution. The cells were then exposed to collagen gels and the degree of contraction of the gel was determined. Results Estrogen at differing concentrations had no effect on the growth of human retinal glial cells. However, after exposed to collagen gel block, less contraction was noted in the estrogen-treated group than in the control group. Conclusions Estrogen can inhibit collagen gel contraction by glial cells. These results suggest a mechanism for macular hole formation, which is observed in menopausal females.

关键词： estrogen human retinal glial cells three-dimensional culture

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Performance evaluation of the backprojection filtered (BPF) algorithm in circular fan-beam and cone-beam CT

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Nuclear Science and Techniques 2006年第2期17卷 113-117页

作者： li liang chen zhi-Qiang ZHANG li KANG Ke-Jun Department of Engineering Physics Tsinghua University Beijing 100084 China

In this article we introduce an exact backprojection filtered (BPF) type reconstruction algorithm for cone-beam scans based on Zou and Pan’s work. The algorithm can reconstruct images using only the projection data passing through the parallel PI-line segments in reduced scans. Computer simulations and practical experiments are carried out to evaluate this algorithm. The BPF algorithm has a higher computational efficiency than the famous FDK algorithm. The BPF algorithm is evaluated using the practical CT projection data on a 450 keV X-ray CT system with a flat-panel detector (FPD). From the practical experiments, we get the spatial resolution of this CT system. The algo- rithm could achieve the spatial resolution of 2.4 lp/mm and satisfies the practical applications in industrial CT inspec- tion.

关键词：反向发射滤波器算法 BPF Hilbert转换算法理论

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The Improvement of Bulk-Heterojunction Order in Polymer Photovoltaic Device

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光谱学与光谱分析 2011年第12期31卷 3175-3179页

作者： YUAN Dan chen zhi-jian XIAO li-xin MU li-ping QU Bo GONG Qi-huang State Key Laboratory for Mesoscopic Physics and Department of Physics Peking UniversityBeijing 100871China

The blend morphology and vertical arrangement are critical to the performance of organic bulk-heterojunction photovoltaic *** the present paper,the authors proposed a new annealing method that controls the blend morphology and vertical arrangement of two materials by means of simultaneously applying external electrical field and violet irradiation on the active layer of poly(3-hexylthiophene) (P3HT) and -phenyl C61-butyric acid methyl ester(PCBM) during annealing *** using this annealing method,the power conversion efficiency increased by 36%,which was caused by vertical phased-separated blend of crystalline P3HT and PCBM and better charge extraction of electrodes.X-ray photoelectron spectroscopy(XPS) was measured to prove more fullerene derivatives at the organic/cathode interfaces by using this annealing *** X-ray diffraction(XRD) analysis and UV-Vis absorption spectrum analysis also revealed more ordered polymer crystallization.

关键词： Polymer photovoltaic device Bulk-heterojunction Annealing method

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基于PSO-RF模型的汉江流域参考作物蒸散量模拟研究

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中国农业气象 2024年第8期45卷 849-859页

作者：葛杰曹绮欣张晓鹏雷龙陈至立冯家豪中国电建集团西北勘测设计研究院有限公司西安710065 河北天和咨询有限公司石家庄050000

选取1960−2017年汉江流域及附近24个气象站的逐日气象数据,构建16种基于粒子群算法优化随机森林(PSO-RF)的日尺度ET0计算模型,并与Hargreaves-Samani、Makkink和Irmark-Allen共3种模型进行比较,评价PSO-RF模型在汉江流域的适用性及可移... 详细信息

选取1960−2017年汉江流域及附近24个气象站的逐日气象数据,构建16种基于粒子群算法优化随机森林(PSO-RF)的日尺度ET0计算模型,并与Hargreaves-Samani、Makkink和Irmark-Allen共3种模型进行比较,评价PSO-RF模型在汉江流域的适用性及可移植性。结果表明:(1)PSO-RF模型能很好地识别各输入参数与日尺度ET0的非线性关系;仅采用最高气温(Tmax)、最低气温(Tmin)和地球外辐射(Ra)建立的PSO-RF2模型具有足够精度,平均MAE为0.402mm·d^(−1),RMSE为0.575mm·d^(−1),R^(2)为0.863;随输入气象要素数量增加,模型计算精度不断升高,平均MAE减小了37.9%,RMSE减小了36.3%,R^(2)升高了6.78%。(2)PSO-RF模型的计算精度优于相同输入参数的Hargreaves-Samani、Makkink和Irmark-Allen模型,平均MAE减小了43.6%、RMSE减小了34.5%,R2升高了4.12%。(3)PSO-RF模型在汉江流域具有较强的泛化能力和可移植性,分区建立的PSO-RF模型相互移植时,平均MAE为0.159mm·d^(−1),RMSE为0.245mm·d^(−1),R^(2)为0.974。因此缺乏气象数据时,基于PSO-RF建立的日尺度ET0计算模型可作为汉江流域日尺度ET0计算的推荐模型。

关键词：汉江流域参考作物蒸散量 PSO RF 可移植性

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Anthocyanin Accumulation Mediated by Blue light and Cytokinin in Arabidopsis Seedlings

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Journal of Integrative Plant Biology 2006年第4期48卷 420-425页

作者： Da-Qing chen zhi-Yang li Rui-Chi Pan Xiao-Jing Wang College of life Sciences South China Normal University Guangdong Key Laboratory of Biotechnology for Plant Development Guangzhou 510631 China

It has been reported that pigmentation In plants Is stimulated by light and cytoklnln （CTK）; however, the signaling pathways and the relationship between light and CTK Involved In the regulation of anthocyanln accumulation remain to be elucidated. We Investigated （i） the role of blue light （BL） and CTK In anthocyanln accumulation ; and （ii） the relationship between BL and CTK In wild type （WT） and by4 mutants of Arabidopsis thaiiana. Two-d-old seedlings grown on medium with or without klnetln （KT） or zeatln （ZT） In darkness were Irradiated using BL at different fluence rates for 3 d before the anthocyanln content was determined using a spectrophotometrlc method. Anthocyanln accumulation was strongly Induced by BL In WT seedlings but not In hy4 seedlings, which demonstrated that CRY1 Is the main photoreceptor for BL. Both KT and ZT enhanced the response of the WT seedlings to BL In a dose-dependent manner, whereas they were not sufficient to promote anthocyanln eccumulatlon In darkness. In addition, data from experiments using the hy4 mutant showed that the CTK effect of BL was also CRYl-dependent. The results from experiments with three different treatment programs showed that the relationship between BL and KT In anthocyanln accumulation of Arabidopsis seedlings seems neither muItlpllcatlve nor additive coactlon, but rather Interaction. BL Is necessary for anthocyanln accumulation, and KT might be Involved In the BL signaling pathway.

关键词： anthocyanin Arabidopsis blue light cytokinin by4 mutant.

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An adpA homologue in Streptomyces avermitilis is involved in regulation of morphogenesis and melanogenesis

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Chinese Science Bulletin 2007年第5期52卷 623-630页

作者： ZHAO JinLei WEN Ying chen zhi SONG Yuan li JiLun Department of Microbiology and Immunology College of Biological Sciences China Agricultural University and Key Laboratory of Agro-Microbial Resource and Application Ministry of Agriculture Beijing 100094 China

In Streptomyces griseus, AdpA, the key transcriptional activator in the A-factor regulatory cascade, switches on the transcription of multiple genes required for secondary metabolism and morphological differentiation. Streptomyces avermitilis also contains an ortholog of adpA, which is named adpA-a. To clarify the in vivo function of adpA-a, an adpA-a-disrupted strain was constructed by double crossover recombination. No difference in avermectin production was found between the adpA-a-disruptant and the wild-type strain. However, this disruptant neither formed spores nor produced melanin and its phenotype was restored to the original wild-type by a single copy of the adpA-a gene integrated into the chromosome. This report shows that adpA-a is involved in regulation of morphological differentiation and melanin production in S. avermitilis.

关键词：灰色链霉菌除虫链霉菌黑素生成 AdpA同族体转化致活因子形态发生次级代谢

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