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Atomic tracking of thermally-driven structural evolution in 2D crystals:Case of NbSe_(2)

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InfoMat 2024年第2期6卷 90-98页

作者： Baofei Hou Teng Zhang Tingting Wang Hongyan Ji huixia Yang Liangguang Jia Xu Han Jingsi Qiao Yu Zhang Liwei liu Hong-Jun Gao Yeliang Wang School of Integrated Circuits and Electronics&Yangtze Delta Region Academy Beijing Institute of TechnologyBeijingthe People's Republic of China Institute of Physics Chinese Academy of SciencesBeijingthe People's Republic of China

Advanced atomic tracking techniques play a critical role in characterizing structural evolution,elucidating fundamental mechanisms of exotic phenomena and tailoring delicate properties.Thermally driven structural modulation in 2D crystals,such as the charge density wave(CDW),often leads to intriguing quantum properties,making them a valuable platform for exploring fundamental physics and potential device applications.However,despite their significance,experimental studies addressing atomic tracking of thermally-driven structural evolution in 2D crystals have been limited.Herein,we utilize high-accuracy variable-temperature atomic tracking measurements with scanning tunneling microscopy(STM)to directly observe a series of structural transitions in a model 2D crystal,namely NbSe_(2).With the atomic tracking technique,we confirm the existence of the universal thermally-driven CDW transition hysteresis between the heating and cooling cycles.This transition hysteresis,characterized by a constant temperature offset,represents a new phenomenon of structural evolution.Our findings provide a feasible method to track CDW transitions at the atomic scale in 2D crystals,significantly contributing to a better understanding and the potential modulation of these materials'functions in nanodevices.

关键词： 2D crystal atomic tracking technique structural evolution temperature hysteresis

Combining gradual and abrupt analysis to detect variation of vegetation greenness on the loess areas of China

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Frontiers of Earth Science 2022年第2期16卷 368-380页

作者： Panxing HE Zongjiu SUN Dongxiang XU huixia liu Rui YAO Jun MA Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology College of Grassland and Environment SciencesXinjiang Agricultural UniversityUrumqi 830000China Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Institute of Biodiversity ScienceFudan UniversityShanghai 200438China School of Earth and Environmental Sciences University of QueenslandQueensland 4072Australia Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China

The annual peak growth and trend shift of vegetation are critical in characterizing the carbon sequestration capacity of ecosystems.As the well-known area with the fastest vegetation growth in the world,the Loess Plateau(LP)lands find an enhanced greening trend in the annual and growing-season.However,the spatiotemporal dynamics of vegetation peak growth and breakpoints characteristics on time series still needs to be explored.Here,we performed tendency analysis to characterize recent variations in annual peak vegetation growth through a satellite-derived vegetation index(NDVI_(max),Maximum Normalized Difference Vegetation Index)and then applied breakpoint analysis to capture abrupt points on the time series.The results demonstrated that the vegetation peak trend had been significantly increasing,with a growth rate at 0.68×10^(-2)·a^(-1) during 2001-2018,and most pixels(70.81%)have a positive linear greening trend over the entire LP.In addition,about 83%of the breakpoint type on the monthly NDVI time series is a monotonic increase at the pixel level,and most pixels(57%)have detected breakpoints after 2010.Our results also showed that the growth rate accelerates in the northwest and decelerates in the southeast after the breakpoint.This study indicates that combining abrupt analysis with gradual analysis can describe vegetation dynamics more effectively and comprehensively.The findings highlighted the importance of breakpoint analysis for monitor timing and shift using time series satellite data at a regional scale,which may help stakeholders to make reasonable and effective ecosystem management policies.

关键词： vegetation greenness gradual trend breakpoint BFAST algorithm the Loess Plateau area

Suppressor tRNA in gene therapy

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Science China Life Sciences 2024年

作者： Jingjing Ruan Xiaoxiao Yu huixia Xu Wenrui Cui Kaiye Zhang Chenyang liu Wenlong Sun Xiaodan Huang Lei An Yue Zhang The Children's Hospital National Clinical Research Center for Child Health Zhejiang University School of MedicineLiangzhu Laboratory Liangzhu Laboratory Zhejiang University School of Medicine Department of Thoracic and Cardiovascular Surgery Huaihe Hospital of Henan University Henan University Translational Medicine Center Huaihe Hospital of Henan University Henan University Eye Center The Second Affiliated Hospital School of Medicine Zhejiang University

Suppressor tRNAs are engineered or naturally occurring transfer RNA molecules that have shown promise in gene therapy for diseases caused by nonsense mutations, which result in premature termination codons(PTCs) in coding sequence, leading to truncated, often nonfunctional proteins. Suppressor t RNAs can recognize and pair with these PTCs, allowing the ribosome to continue translation and produce a full-length protein. This review introduces the mechanism and development of suppressor t RNAs, compares suppressor tRNAs with other readthrough therapies, discusses their potential for clinical therapy, limitations, and obstacles. We also summarize the applications of suppressor tRNAs in both in vitro and in vivo, offering new insights into the research and treatment of nonsense mutation diseases.

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Adipo8, a high-affinity DNA aptamer, can differentiate among adipocytes and inhibit intracellular lipid accumulation in vitro

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Science China Chemistry 2015年第10期58卷 1612-1620页

作者： Ke Chen Jun liu Guoxiang Tong Bo liu Guodong Wang huixia liu Xiangya Hospital Central South University

Obesity is primarily caused by the excessive accumulation of white adipose tissues(WAT). We previously obtained an adipocyte-specific aptamer termed Adipo8 in vitro. In this present study, this adipocyte-specific aptamer Adipo8 was first chemically modified by introduction of phosphorothioate linkages(PS-linkages) and then conjugated to polyethylene glycol(PEG), we tested whether this modified aptamer could distinguish mature white adipocytes from 3T3-L1 preadipocytes or brown adipocytes. To verify the binding affinity of this aptamer to mature white adipocytes in vivo as well as in vitro, we tested whether modified Adipo8 could specifically bind to the WAT of Diet-Induced Obesity(DIO) C57BL/6 mice. Finally, we examined the effect of Adipo8 on the adipogenic differentiation of mature white adipocytes. Based on our results, PS-modified aptamer demonstrated its high binding affinity and specificity, and was able to distinguish white adipocytes from 3T3-L1 preadipocytes or brown adipocytes in vitro. PS-modified Adipo8 also demonstrated more biostability and prolonged binding time in biological fluids. Additionally, Adipo8 could inhibit adipogenic differentiation of adipose tissue, possibly by inhibiting the expression of PPAR-γ in adipose tissue. This modified aptamer holds great promise as a stable molecular recognition tool for targeted delivery to adipocytes and has potential in the treatment of obesity.

关键词：前脂肪细胞体外抑制适配体亲和力核酸脂质蓄积细胞内脂肪细胞分化

利用单细胞测序和转录组测序建立结直肠癌免疫细胞的9基因预后模型

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中国癌症杂志 2024年第6期34卷 548-560页

作者：唐楠黄慧霞刘晓健复旦大学附属肿瘤医院肿瘤内科复旦大学上海医学院肿瘤学系上海200032 复旦大学附属肿瘤医院病理科复旦大学上海医学院肿瘤学系上海200032 复旦大学附属肿瘤医院肿瘤研究所上海200032 复旦大学病理学研究所上海200032

背景与目的:结直肠癌(colorectal carcinoma,CRC)是一种常见的恶性肿瘤,其发病率和死亡率仅次于胃癌和食管癌,在消化系统恶性肿瘤中居第二位。越来越多的证据表明,免疫细胞在CRC的发生、发展中发挥着重要作用。本研究旨在构建一个与免... 详细信息

背景与目的:结直肠癌(colorectal carcinoma,CRC)是一种常见的恶性肿瘤,其发病率和死亡率仅次于胃癌和食管癌,在消化系统恶性肿瘤中居第二位。越来越多的证据表明,免疫细胞在CRC的发生、发展中发挥着重要作用。本研究旨在构建一个与免疫细胞相关的基因的预后模型,以预测CRC患者的预后并进行精准管理。方法:从基因表达综合(Gene Expression Omnibus,GEO)数据库和癌症基因图谱(The Cancer Genome Atlas,TCGA)数据库下载结直肠癌的单细胞RNA测序(single-cell RNA sequencing,scRNA-seq)和普通转录组测序(RNA sequencing,RNA-seq)数据以及临床信息,提取免疫细胞亚型的差异基因,通过Cox回归和LASSO回归分析在TCGA数据中筛选出与预后相关的基因,同时使用GSE39582和GSE41258进行外部验证。基于预后模型进行化疗药物敏感性分析、免疫治疗效果分析、风险评分相关的通路分析以及临床相关性分析。采用实时荧光定量聚合酶链反应(real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR)和免疫组织化学检测验证模型基因在10例经术后病理学检查的新鲜冷冻结直肠癌样本和细胞系中的表达水平,样本采集均已获得复旦大学附属肿瘤医院伦理委员会的批准(伦理编号:050432-4-2108*)。结果:本研究根据scRNA-seq数据集(GSE161277)定义了16个细胞群,并通过R包celldex将这些群标记为不同的细胞类型。然后对免疫细胞亚型进行差异分析,共获得了374个差异表达基因。通过单因素Cox和LASSO回归分析,本研究在CRC中构建了一个9基因风险预后模型。该风险模型表现出对预后的可靠预测效果,对预测抗肿瘤药物敏感性、免疫治疗效果、潜在分子机制及临床特征等方面起重要作用,高风险分数的患者从免疫疗法中受益概率较低。结论:我们基于CRC肿瘤微环境中免疫细胞的异质性构建了一个包含9个基因的风险预后模型,并据此预测了CRC患者的生存和治疗效果。

关键词：结直肠癌预后模型肿瘤免疫与免疫治疗药物筛选 scRNA-seq

热应激对羊成肌细胞部分miRNA的影响及其生物信息学分析与靶基因预测

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南京农业大学学报 2024年第1期47卷 193-204页

作者：卢佳伟赵鹏刘媛魏宗友李惠侠南京农业大学动物科技学院江苏南京210095 太仓市农业农村科技服务中心江苏太仓215400

[目的]本文旨在探究热应激对羊成肌细胞部分miRNA的影响,并对miR-23a、miR-24、miR-27a-3p和miR-30a-5p进行生物信息学分析与靶基因预测,揭示热应激下miRNA影响骨骼肌发育的调控机制。[方法]通过RT-qPCR技术研究热应激对羊成肌细胞miRN... 详细信息

[目的]本文旨在探究热应激对羊成肌细胞部分miRNA的影响,并对miR-23a、miR-24、miR-27a-3p和miR-30a-5p进行生物信息学分析与靶基因预测,揭示热应激下miRNA影响骨骼肌发育的调控机制。[方法]通过RT-qPCR技术研究热应激对羊成肌细胞miRNA表达量的影响;利用miRBase数据库获取不同物种中miR-23a、miR-24、miR-27a-3p和miR-30a-5p的前体序列和成熟序列,并利用MEGA X软件构建系统进化树进行相似性分析;通过TargetScan、miRDB、RNA22、miRWalk对上述miRNA进行靶基因预测,使用DAVID对预测出的共同靶基因进行GO功能与KEGG通路富集分析,最后进行miRNA、共同靶基因与KEGG通路的关联分析。[结果]热应激显著下调羊成肌细胞在增殖阶段与分化阶段miRNA的表达。miR-23a、miR-24、miR-27a和miR-30a在不同物种间的保守性较高,除了牛的miR-24以外,成熟序列基本相同,种子序列完全一致。预测出的共同靶基因主要富集在细胞增殖、分化、周期、凋亡、迁移等GO条目,以及mTOR、TGFβ、MAPK、Ras、ErbB、FoxO和PI3K-Akt等KEGG通路。关联分析表明miR-24和miR-27a-3p可能靶向NLK和TAOK1以参与MAPK和FoxO信号通路来调控骨骼肌的发育。[结论]miR-23a、miR-24、miR-27a和miR-30a在不同物种中保守性较高,热应激下调羊成肌细胞部分miRNA的表达,可能影响骨骼肌的发育。

关键词：热应激成肌细胞 miRNA 生物信息学靶基因

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某座椅鞭打试验仿真与优化

汽车技术 2024年第6期 55-62页

作者：王元兰赵军毛晨曦刘会霞江苏大学镇江212013 上海埃立曼科技有限公司上海201112

针对某款座椅在鞭打试验中假人挥鞭伤较为严重,鞭打得分较低的问题,利用HyperMesh软件建立座椅有限元模型,并进行鞭打仿真分析,得到对鞭打伤害影响较大的因素分别为调角器刚度系数、头枕杆直径、靠背左侧支撑板厚度、靠背右侧支撑板厚... 详细信息

针对某款座椅在鞭打试验中假人挥鞭伤较为严重,鞭打得分较低的问题,利用HyperMesh软件建立座椅有限元模型,并进行鞭打仿真分析,得到对鞭打伤害影响较大的因素分别为调角器刚度系数、头枕杆直径、靠背左侧支撑板厚度、靠背右侧支撑板厚度、靠背后部支撑板厚度、座垫右侧支撑板厚度和座垫左侧支撑板厚度,利用哈默斯雷试验设计方法对上述7个设计变量进行样本点采集,并利用移动最小二乘法进行近似模型拟合,采用全局响应面法对近似模型进行多目标优化,验证结果表明,优化模型的精度满足要求,优化后鞭打得分提高,座椅抗挥鞭伤性能显著提升。

关键词：座椅鞭打试验挥鞭伤中国新车评价规程多目标优化

巴利昔单抗短期替代钙调蛋白抑制剂预防急性移植物抗宿主病的探索性研究

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中华血液学杂志 2024年第2期45卷 115-120页

作者：邵珊刘慧霞蒋瑛李肃魏道林朱骏王椿赵初娴上海闸新中西医结合医院骨髓移植科上海200040

目的探讨在钙调蛋白抑制剂(CNI)不耐受患者中短期应用重组抗CD25人源化单克隆抗体巴利昔单抗(Basiliximab)单药预防异基因造血干细胞移植(allo-HSCT)后急性移植物抗宿主病(GVHD)的有效性。方法本研究纳入2021年8月至2022年8月在上海闸... 详细信息

目的探讨在钙调蛋白抑制剂(CNI)不耐受患者中短期应用重组抗CD25人源化单克隆抗体巴利昔单抗(Basiliximab)单药预防异基因造血干细胞移植(allo-HSCT)后急性移植物抗宿主病(GVHD)的有效性。方法本研究纳入2021年8月至2022年8月在上海闸新中西医结合医院骨髓移植科行挽救性allo-HSCT后因CNI严重不良反应而应用巴利昔单抗预防急性GVHD的17例难治性恶性血液病患者。男7例,女10例,中位年龄43(18~67)岁。停用CNI后,给予巴利昔单抗1 mg/kg每周1次进行替代预防,直至患者有条件重新启用CNI或哺乳动物雷帕霉素靶体蛋白(mTOR)抑制剂。结果巴利昔单抗的替代预防中位开始时间为移植后5(1~32)d,替代治疗中位持续时间为20(7~120)d。所有患者均获得粒细胞植入,中位植入时间12(10~17)d。13例患者获得血小板植入,中位植入时间13(11~20)d。8例(47.1%)患者发生Ⅱ~Ⅳ度急性GVHD,4例(23.6%)发生Ⅲ/Ⅳ度急性GVHD。仅有1例患者死于急性GVHD。至随访截止,17例患者中7例死亡,存活患者中随访最长时间为347 d,中位生存时间未达到,移植后6个月总生存率为62.6%。17例患者中,13例(76.4%)发生巨细胞病毒再激活,7例(41.2%)发生EB病毒激活,未发生巨细胞病毒病。结论在allo-HSCT过程中出现CNI不耐受时,短期单药应用巴利昔单抗可作为急性GVHD的替代预防方案。

关键词：重组抗CD25人源化单克隆抗体异基因造血干细胞移植钙调蛋白抑制剂移植物抗宿主病

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胶轮地铁导向轮受力分析及影响因素研究

技术与市场 2024年第6期31卷 63-66页

作者：廖从建刘晖霞中车株洲电力机车有限公司湖南株洲412001

胶轮地铁导向轮在运用中常出现异常磨耗和损伤问题。为研究导向轮发生故障的原因,对导向轮受力情况进行了分析并对影响导向轮载荷的各种因素进行研究。研究发现,车辆的运行线路、载荷、速度、轮胎状态、一二系簧刚度结构均会影响导向轮... 详细信息

胶轮地铁导向轮在运用中常出现异常磨耗和损伤问题。为研究导向轮发生故障的原因,对导向轮受力情况进行了分析并对影响导向轮载荷的各种因素进行研究。研究发现,车辆的运行线路、载荷、速度、轮胎状态、一二系簧刚度结构均会影响导向轮的受力,因此应该结合上述因素来查找导向轮故障原因。

关键词：胶轮地铁导向轮载荷分析

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