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玄武岩纤维/聚乳酸/聚β-羟基丁酸酯复合材料的制备及加工性能和热性能 被引量:1
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作者 陈涛涛 辛勇 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2022年第8期89-94,103,共7页
以聚乳酸(PLA)、聚β-羟基丁酸酯(PHB)和玄武岩纤维(BF)为原料,通过一步反应熔融共混工艺,注塑成型制备出BF/PLA/PHB复合材料。探究了BF的含量对PLA/PHB基体复合材料的力学、热学以及流变性能的影响。通过拉伸测试,BF/PLA/PHB复合材料... 以聚乳酸(PLA)、聚β-羟基丁酸酯(PHB)和玄武岩纤维(BF)为原料,通过一步反应熔融共混工艺,注塑成型制备出BF/PLA/PHB复合材料。探究了BF的含量对PLA/PHB基体复合材料的力学、热学以及流变性能的影响。通过拉伸测试,BF/PLA/PHB复合材料中BF的质量分数增加到10%时,复合材料的拉伸强度和断裂伸长率虽然达到最大,但上升幅度明显减弱。通过X射线衍射以及差示扫描量热分析得出,加入的BF在PLA/PHB基体当中起到异相成核的作用,提升了PLA/PHB基体材料的结晶度,复合材料中BF质量分数超过5%时,结晶度提升明显减弱,达到阈值。通过旋转流变仪表征得出复合材料BF/PLA/PHB中BF质量分数增加到2%时,达到流变渗流阈值,继续增加BF含量,其复合材料的复数黏度将会显著提升,流动性差,不利于工程应用加工。 展开更多
关键词 复合材料 玄武岩纤维 拉伸强度 断裂伸长率 热性能 流变性能
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Yamanaka factors critically regulate the developmental signaling network in mouse embryonic stem cells 被引量:6
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作者 Xiaosong Liu Jinyan Huang +5 位作者 taotao chen Ying Wang Shunmei Xin Jian Li Gang Pei Jiuhong Kang 《Cell Research》 SCIE CAS CSCD 2008年第12期1177-1189,共13页
Yamanaka factors (Oct3/4, Sox2, Klf4, c-Myc) are highly expressed in embryonic stem (ES) cells, and their overexpression can induce pluripotency in both mouse and human somatic cells, indicating that these factors... Yamanaka factors (Oct3/4, Sox2, Klf4, c-Myc) are highly expressed in embryonic stem (ES) cells, and their overexpression can induce pluripotency in both mouse and human somatic cells, indicating that these factors regulate the developmental signaling network necessary for ES cell pluripotency. However, systemic analysis of the signaling pathways regulated by Yamanaka factors has not yet been fully described. In this study, we identified the target promoters of endogenous Yamanaka factors on a whole genome scale using ChIP (chromatin immunoprecipitation)- on-chip in El4.1 mouse ES cells, and we found that these four factors co-occupied 58 promoters. Interestingly, when Oct4 and Sox2 were analyzed as core factors, Klf4 functioned to enhance the core factors for development regulation, whereas c-Myc seemed to play a distinct role in regulating metabolism. The pathway analysis revealed that Yamanaka factors collectively regulate a developmental signaling network composed of 16 developmental signaling pathways, nine of which represent earlier unknown pathways in ES cells, including apoptosis and cellcycle pathways. We further analyzed data from a recent study examining Yamanaka factors in mouse ES ceils. Interestingly, this analysis also revealed 16 developmental signaling pathways, of which 14 pathways overlap with the ones revealed by this study, despite that the target genes and the signaling pathways regulated by each individual Yamanaka factor differ significantly between these two datasets. We suggest that Yamanaka factors critically regulate a developmental signaling network composed of approximately a dozen crucial developmental signaling pathways to maintain the pluripotency of ES cells and probably also to induce pluripotent stem cells. 展开更多
关键词 embryonic stem cell PLURIPOTENCY Yamanaka factor signal pathway CHIP-ON-CHIP
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More synergetic cooperation of Yamanaka factors in induced pluripotent stem cells than in embryonic stem cells 被引量:4
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作者 Jinyan Huang taotao chen +7 位作者 Xiaosong Liu Jing Jian Jinsong Li Dangsheng Li X Shirley Liu Wei Li Jiuhong Kang Gang Pei 《Cell Research》 SCIE CAS CSCD 2009年第10期1127-1138,共12页
The role of Yamanaka factors as the core regulators in the induction of pluripotency during somatic cell reprogramming has been discovered recently. Our previous study found that Yamanaka factors regulate a developmen... The role of Yamanaka factors as the core regulators in the induction of pluripotency during somatic cell reprogramming has been discovered recently. Our previous study found that Yamanaka factors regulate a developmental signaling network in maintaining embryonic stem (ES) cell pluripotency. Here, we established completely reprogrammed induced pluripotent stem (iPS) cells and analyzed the global promoter occupancy of Yamanaka factors in these cells by ChiP-chip assays. We found that promoters of 565 genes were co-bound by four Yamanaka factors in iPS cells, a 10-fold increase when compared with their binding in ES cells. The promoters occupied by a single Yamanaka factor distributed equally in activated and repressed genes in iPS cells, while in ES cells Oct4, Sox2, or KIf4 distributed mostly in repressed genes and c-Myc in activated ones. Pathway analysis of the ChiP-chip data revealed that Yamanaka factors regulated 16 developmental signaling pathways in iPS cells, among which 12 were common and 4 were unique compared to pathways regulated in ES ChiP-chip dataset in iPS cells and observed similar results, cells. We further analyzed another recently published showing the power of ChiP-chip plus pathway analysis for revealing the nature of pluripotency maintenance and regeneration. Next, we experimentally tested one of the repressive signaling pathways and found that its inhibition indeed improved efficiency of cell reprogramming. Taken together, we proposed that there is a core developmental signaling network necessary for pluripotency, with TGF-β, Hedgehog, Wnt, p53 as repressive (Yin) regulators and Jak-STAT, cell cycle, focal adhesion, adherens junction as active (Yang) ones; and Yamanaka factors synergistically regulate them in a Yin-Yang balanced way to induce pluripotency. 展开更多
关键词 PLURIPOTENCY REPROGRAMMING Yamanaka factor signal pathway CHIP-CHIP
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一种新型语义网络分析模型对室间隔完整型肺动脉闭锁和危重肺动脉瓣狭窄胎儿右心发育不良程度的评价作用
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作者 罗刚 泮思林 +4 位作者 孙玲玉 李志新 陈涛涛 乔思波 庞善臣 《中华医学超声杂志(电子版)》 CSCD 北大核心 2024年第4期377-383,共7页
目的分析评价一种新型语义网络分析模型SPReCHD:残差学习诊断系统模块(RLDS)和双路径链式多尺度门控轴心变压器网络模块(DPC-MSGATNet),在室间隔完整型肺动脉闭锁(PA/IVS)和危重肺动脉瓣狭窄(CPS)胎儿超声心动图四腔心视图数据集中评估... 目的分析评价一种新型语义网络分析模型SPReCHD:残差学习诊断系统模块(RLDS)和双路径链式多尺度门控轴心变压器网络模块(DPC-MSGATNet),在室间隔完整型肺动脉闭锁(PA/IVS)和危重肺动脉瓣狭窄(CPS)胎儿超声心动图四腔心视图数据集中评估右心发育不良程度分级的性能。方法回顾性收集2017年6月至2022年12月青岛大学附属妇女儿童医院350例24~28周胎龄的PA/IVS和CPS胎儿的1650张单幅超声心动图四腔心视图建立实验数据集。根据右心发育不良程度对建立的SPReCHD模型进行训练、验证和测试,评估模型精确度、召回率及F1值等性能指标;与高级医师基于超声指标、右心室形态及出生结局等多维度信息对测试集做出的评估结果进行比较,采用Kappa检验观察评估的一致性。结果SPReCHD模型在训练集、验证集及测试集对右心发育不良程度分级评估的精确度分别为93.82%、94.34%和94.68%,召回率分别为90.54%、91.38%和90.89%,F1值分别为92.10%、92.82%和92.67%。在测试集中,SPReCHD模型与高级儿童心血管医师评估结果一致性良好(Kappa值=0.724,P<0.001)。结论SPReCHD模型在训练集、验证集及测试集对右心发育不良程度分级的评估性能优异。该模型对PA/IVS和CPS胎儿右心发育不良程度分级评估水平与高级医师评估结果一致性好,为进一步提出精准评估标准奠定基础。 展开更多
关键词 深度学习 室间隔完整型肺动脉闭锁 危重度肺动脉瓣狭窄 右心发育不良 超声心动图 胎儿 人工智能
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Creation of high position fetal balloon atrial septoplasty for hypoplastic left heart syndrome and highly restrictive atrial septum: A case report and literature review
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作者 Ai Zhang Gang Luo +2 位作者 Yue Sun taotao chen Silin Pan 《Journal of Interventional Medicine》 2020年第1期55-57,共3页
Background:Fetal balloon atrial septoplasty(BAS)is performed through the restrictive foramen ovale in fetal cases with established hypoplastic left heart syndrome(HLHS)and an intact or highly restrictive atrial septum... Background:Fetal balloon atrial septoplasty(BAS)is performed through the restrictive foramen ovale in fetal cases with established hypoplastic left heart syndrome(HLHS)and an intact or highly restrictive atrial septum(RAS).Methods:In the current report,we present a case of high position BAS in a fetus with HLHS/RAS.Results:Echocardiography confirmed an adequate atrial opening above the foramen ovale and fetal pleural effusion resolved spontaneously 1 day after the procedure.Conclusion:To the best of our knowledge,the creation of a high position hole in the thinner part of the atrial septum,instead of the restrictive tiny hole,has not been reported in fetal cases with HLHS/RAS. 展开更多
关键词 Congenital heart disease Fetal balloon atrial septoplasty Hypoplastic left heart syndrome Intact or highly restrictive atrial septum
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Effects of zeolite application on grain yield,water use and nitrogen uptake of rice under alternate wetting and drying irrigation
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作者 Junlin Zheng taotao chen +3 位作者 Guimin Xia Wei chen Guangyan Liu Daocai Chi 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2018年第1期157-164,共8页
With the increasing scarcity of water resources and growing population,the dual goal of saving irrigation water and increasing grain yield has become a major challenge in rice production around the world.A two-year ly... With the increasing scarcity of water resources and growing population,the dual goal of saving irrigation water and increasing grain yield has become a major challenge in rice production around the world.A two-year lysimetric experiment was conducted to assess the effects of zeolite application(Z_(0):0 and Z1:15 t/hm^(2) and water regimes(W_(0):continuous flooding irrigation,W1:energy-controlled irrigation,W2:alternate wetting and drying irrigation)on grain yield,water use and total nitrogen uptake of rice.Zeolite addition to paddy field significantly increased grain yield,total N uptake,and water use efficiency(WUE),despite a negligible effect on amount of irrigation water used.Compared with W_(0),the separate use of W_(1) and W_(2) each considerably decreased irrigation water.However,W2-grown rice showed a significant decline in grain yield.In contrast,W1 showed comparable grain yield with W_(0),and achieved the highest WUE.Correlation analysis revealed that grain yield was significantly and positively correlated with effective panicles,spikelets per panicle,water consumption,and total N uptake.It is concluded that the combination of zeolite application at the rate of 15 t/hm^(2) and energy-controlled irrigation could be recommended to benefit farmers by reducing irrigation water while improving grain yield on a clay loam soil. 展开更多
关键词 ZEOLITE alternate wetting and drying irrigation RICE YIELD water use efficiency
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