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The circadian mutation PER2S662G is linked to cell cycle progression and tumorigenesis

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The circadian mutation PER2S662G is linked to cell cycle pro...

Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

2011年全国时间生物医学学术会议

作者： X Gu~(1,31),L Xing~(1,3),G shi~1,z Liu~1,X Wang~1,z Qu~1,X Wu~1,z Dong~1,X Gao~1,G Liu~1,L Yang~(*,2) and Y Xu~(*,1) 1 MOE Key Laboratory of Model Animal for Disease Study,Model Animal Research Center,Nanjing University,Nanjing, 210061 2 Center for Systems Biology,Soochow University,Soochow,215006

Circadian oscillation and cell cycle progression are the two most essential rhythmic events present in almost all *** rhythms keep track of time and provide temporal regulation with a period of about 24 *** cell cycle is optimized for growth and division,but not for time *** gated cell divisions are observed in nearly all ***,the implications of this coupling to the physiology of mammals are unknown.A mutation(S662G) in the clock protein PERIOD2(PER2) is responsible for familial advanced sleep phase syndrome in which sleep onset occurs in the early evening and wakefulness occurs in the early ***,we provide evidence that the PER2 mutation leads to enhanced resistance to X-ray-induced apoptosis and increased E1A- and RAS-mediated oncogenic ***,the PER2 mutation affects tumorigenesis in cancer-sensitized p53 ***,analyzing the clock-controlled cell cycle genes p21,c-Myc,Cyclin D1 and p27,we found that the relative phases between p21 and Cyclin D expression profiles have been changed significantly in these Per2 allele mutant mouse embryonic *** key role of the Per2-mediated phase alteration of p21 provides what we believe to be a novel mechanism in understanding cell cycle progression,its plasticity and its resistance to interference.

关键词： PER2 circadian rhythms cell cycle tumorigenesis FASPS

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN T.ASGHAR z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： hybrid nanofluid oscillating curved stretchable sheet gyrotactic microorganism Cattaneo-Christov heat and mass flux chemical reaction analytical solution O368

多层螺旋CT灌注扫描成像技术评价正常胰腺和胰腺癌的血流动力学特点

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中国组织工程研究与临床康复 2007年第22期11卷 4284-4287页

作者：文戈张雪林李颖嘉吴慧莹曲华丽石珍南方医科大学南方医院影像中心广东省广州市510515

目的:利用多层螺旋CT的肿瘤灌注软件,对胰腺生理及病理情况下的血流动力学变化进行定量分析和评价。方法:①分组:2005-01/2006-12南方医科大学南方医院收治的确诊胰腺癌患者20例为胰腺癌组,30例正常胰腺(健康查体或胰外病变)为对照组。... 详细信息

目的:利用多层螺旋CT的肿瘤灌注软件,对胰腺生理及病理情况下的血流动力学变化进行定量分析和评价。方法:①分组:2005-01/2006-12南方医科大学南方医院收治的确诊胰腺癌患者20例为胰腺癌组,30例正常胰腺(健康查体或胰外病变)为对照组。②扫描方法:所有受试者均用GELightspeed16排螺旋CT机行胰腺CT灌注检查,采用轴扫方式,120kV,60mA,5mm层厚×4层,矩阵512×512,成像速度1帧/s。扫描前肘部静脉埋置20G留置针,采用高压注射器注射非离子型对比剂50mL(每毫升含300mgI),注射速率4.0mL/s,延迟6s,总扫描时间60s。③评估指标:所得数据传输至GEAW4.2工作站,利用Perfusion3中的胰腺灌注软件进行数据处理,分别测量达峰时间、峰值高度、血流量、血容量、平均通过时间和毛细血管表面通透性的平均值。结果:50例均进入结果分析。①胰腺癌组的达峰时间较对照组长[(27.75±9.87),(22.12±4.26)s,P<0.05],峰值高度小于对照组[(23.12±7.03),(69.47±14.46)Hu,P<0.01]。②胰腺癌组的血流量、血容量明显小于对照组(P均<0.01),毛细血管通透性和平均通过时间大于对照组(P<0.01)。结论:①多层螺旋CT灌注成像可定量分析胰腺生理及病理情况下的血流动力学变化,有一定临床应用价值。②胰腺癌组织血流量和血容量减少,灌注峰值降低,毛细血管同头性增高,灌注达峰时间和平均通过时间延长。

关键词：体层摄影术,X线计算机胰腺癌灌注

肝损伤Balb-c小鼠用于细胞移植治疗的有效亚致死放疗剂量

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中国组织工程研究与临床康复 2007年第4期11卷 645-648,I0001页

作者：陈曦丰岩清王莹石铸黄东锋黄劭敏梁秀龄中山大学附属第一医院康复科广东省广州市510080 中山大学附属第一医院神经科广东省广州市510080 中山大学附属肿瘤医院放射治疗科广东省广州市510060

目的:探索肝损伤Balb-c小鼠适合的亚致死性放疗剂量,为细胞移植治疗用于肝病动物模型提供预处理方案。方法:实验于2004-10/2005-06在中山大学附属第一医院神经科实验室和中山大学实验动物中心完成。供体鼠为48只雄性Balb-c小鼠,受体鼠... 详细信息

目的:探索肝损伤Balb-c小鼠适合的亚致死性放疗剂量,为细胞移植治疗用于肝病动物模型提供预处理方案。方法:实验于2004-10/2005-06在中山大学附属第一医院神经科实验室和中山大学实验动物中心完成。供体鼠为48只雄性Balb-c小鼠,受体鼠为24只雌性Balb-c小鼠。24只雌性受体鼠以2-乙酰氨基芴法建立肝损伤模型,根据γ射线照射剂量按随机数字表法分为4组,即γ射线8Gy,7Gy,6Gy和5Gy照射组,每组6只。放疗后当天接受带有CM-Dil荧光标记的供体雄性小鼠骨髓干细胞移植,每只受体小鼠移植骨髓干细胞1.0×107个。移植后追踪12周,观察受体鼠的一般情况及移植物抗宿主病反应,检测干细胞示踪剂CM-DiI(积分吸光度值)和供体雄性Sry基因(Sry与β-actin扩增产物积分吸光度比值)在受体鼠肝脏中的表达,以明确供体细胞在受体鼠肝脏存活情况。结果:放疗后γ射线8Gy照射组小鼠在放疗后4～10d内全部死亡,γ射线7Gy照射组死亡4只,共14只小鼠进入结果分析。①移植后受体鼠的移植物抗宿主病情况比较:γ射线7Gy照射组移植后第1周时移植物抗宿主病症状明显,4周后完全消失;γ射线5,6Gy照射组移植物抗宿主病症状轻微,持续3周消失。②各组受体小鼠肝脏中的CM-DiI分布情况比较:γ射线5,6,7Gy照射组CM-DiI积分吸光度值分别为2.86±0.72,2.65±0.55,2.53±0.42,3组相比差异无显著性意义(P>0.05)。③各组受体小鼠肝脏中雄性Sry基因的表达情况比较:γ射线7,6和5Gy照射组Sry与β-actin扩增产物积分吸光度比值分别为0.194±0.015,0.213±0.031,0.208±0.027,各组间差异无显著性意义(P>0.05)。结论:鉴于外周血细胞被供体细胞取代量随着放疗剂量增加而增加的理论,肝损伤Balb-c小鼠模型用于细胞移植研究的适合亚致死性放疗剂量是6Gy。

关键词：肝疾病干细胞移植放射治疗剂量疾病模型,动物

Transient chemical-mediated epigenetic modulation confers unrestricted lineage potential on human primed pluripotent stem cells

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Science China Life Sciences 2025年

作者： shi Chen Yuanyuan He Lejun Lv Bei Liu Cheng Li Hongkui Deng Jun Xu Department of Cell Biology School of Basic Medical Sciences Peking University Stem Cell Research Center Peking University Health Science Center Peking University Academy of Advanced Interdisciplinary Studies Peking University BeiCell Therapeutics School of Life Sciences Center for Bioinformatics Center for Statistical Science Peking University MOE Engineering Research Center of Regenerative Medicine School of Basic Medical Sciences State Key Laboratory of Natural and Biomimetic Drugs Peking University Health Science Center and the MOE Key Laboratory of Cell Proliferation and Differentiation College of Life Sciences Peking-Tsinghua Center for Life Sciences Peking University

Human primed pluripotent stem cells are capable of generating all the embryonic ***,their extraembryonic trophectoderm potentials are *** remains unclear how to expand their developmental potential to trophectoderm *** we show that transient treatment with a cocktail of small molecule epigenetic modulators imparts trophectoderm lineage potentials to human primed pluripotent stem cells while preserving their embryonic *** chemically treated cells can generate trophectoderm-like cells and downstream trophoblast stem cells,diverging into syncytiotrophoblast and extravillous trophoblast *** and CUT&Tag analyses reveal that these induced cells share transcriptional profiles with in vivo trophectoderm and cytotrophoblast,and exhibit reduced H3K27me3 modification at gene loci specific to trophoblast lineages compared with primed pluripotent *** exploration highlighted the critical roles of epigenetic modulators HDAC2,EzH1/2,and KDM5s in the activation of trophoblast lineage *** findings demonstrate that transient epigenetic resetting activates unrestricted lineage potential in human primed pluripotent stem cells,and offer new mechanistic insights into human trophoblast lineage specification and in vitro models for studying placental development and related disorders.

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Efficient photocatalytic reduction of CO2 to formate by a molecular noble metal-free system

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Science China Chemistry 2025年第1期 152-156页

作者： Lihua zhang Lingjing Chen Huatian shi Yue Wei Gui Chen Tai-Chu Lau School of Environment and Civil Engineering Research Center for Eco-environmental Engineering Dongguan University of Technology Department of Chemistry and Institute of Molecular Functional Materials City University of Hong Kong

Reducing CO2to carbon-neutral solar fuels can not only alleviate the energy demand but also mitigate the greenhouse *** present,developing an efficient non-noble metal photo/electrocatalytic system for converting CO2to a specific product beyond CO is still a big ***,we report a new cobalt complex bearing 2,2′-bi-1,10-phenanthroline ligand that can photocatalytically reduce CO2to formate （HCOO-）.Turnover number （TON） for HCOO-up to 677 with 99%selectivity can be achieved using organic dyes purpurin as photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole （BIH） as sacrificial reductant in a CO2-saturated NMP/TEA （v/v,3:1） solution under visible light *** potential electrolysis at-1.41 V （***/Ag Cl） in the presence of 12 m M Et3NHBF4also produced HCOO-with Faradaic efficiency of 39%.Spectroscopic and electrochemical studies suggest that a[CoI-H]species is the key intermediate for CO2reduction.

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Polyethylene glycol fusion repair of severed rat sciatic nerves reestablishes axonal continuity and reorganizes sensory terminal fields in the spinal cord

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Neural Regeneration Research 2025年第7期20卷 2095-2107页

作者： Emily A.Hibbard Liwen zhou Cathy z.Yang Karthik Venkudusamy Yessenia Montoya Alexa Olivarez George D.Bittner Dale R.Sengelaub Program in Neuroscience Indiana UniversityBloomingtonINUSA Department of Neuroscience University of Texas at AustinAustinTXUSA

Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically *** used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic *** have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor ***,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target *** this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic *** adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of *** action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury *** success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days *** 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish ***-fusion repair reestablished axonal *** to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal ***,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repa

关键词： axotomy dorsal horn peripheral nerve injury plasticity polyethylene glycol(PEG) sciatic nerve sensory terminals wheat germ agglutinin horseradish peroxidase

波浪在不平坦海岸底床上传播的平面二维数学模型

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中国港湾建设 2014年第1期34卷 8-13页

作者：彭延建刘应中时钟上海交通大学船舶海洋与建筑工程学院港口与海岸工程系海洋工程国家重点实验室上海200030

基于线性波浪理论,利用摄动理论中的多重尺度法,以坡度ε为小参数,Liu和shi[1]推导出波浪在不平坦底床传播的波幅方程,以及一阶势函数的解析解。为验证该模型是否可用于平面二维波浪传播问题,利用有限差分法,分别对波幅方程和边界条件... 详细信息

基于线性波浪理论,利用摄动理论中的多重尺度法,以坡度ε为小参数,Liu和shi[1]推导出波浪在不平坦底床传播的波幅方程,以及一阶势函数的解析解。为验证该模型是否可用于平面二维波浪传播问题,利用有限差分法,分别对波幅方程和边界条件进行离散和求解,得到因折射、绕射引起的波幅和波向的变化。通过引入绕射因子,使该模型的应用范围更为广泛,并且计算精度得到提高。将计算得到的波向和波高与Berkhoff[2]、Berkhoff等[3]椭圆形浅滩试验值进行比较,表明该模型可以应用于平面二维问题。

关键词：多重尺度法波浪传播不平坦底床

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略论唐代宰相制度

史学集刊 2025年第1期 88-97页

作者：孟宪实中国人民大学历史学院北京100872

在中国古代政治制度史中,宰相制度无疑是一个重要课题。众所周知,在讨论中国的皇帝制度时,有一个重要的观点是讨论“君权”与“相权”的斗争,而君权的不断增长、相权的不断被削弱,正是君主专制持续发展的重要途径。事实上,各个时期的宰... 详细信息

在中国古代政治制度史中,宰相制度无疑是一个重要课题。众所周知,在讨论中国的皇帝制度时,有一个重要的观点是讨论“君权”与“相权”的斗争,而君权的不断增长、相权的不断被削弱,正是君主专制持续发展的重要途径。事实上,各个时期的宰相制度既有变迁,又各具特色,从每个朝代的宰相制度是否能够得出君主专制获得发展的结论,显然是需要具体论证的。唐代宰相制度的研究,通常是在三省制的背景下展开的,而唐代的宰相制度也有自己的发展变化。唐代宰相制度经过三个历史时期,政事堂时期是兼职宰相时期,中书门下时期是专职宰相时期。自唐后期至北宋,是首相制时期。唐代宰相制度的变化,是不是君相斗争的结果?而从兼职宰相到专职宰相再到首相制,宰相的职权明显是处在加强的进程中,按照君相斗争的习惯思路,难道是君主在君相斗争中败下阵来?恐怕不能得出这样的结论。此外,唐宋历史的关系,向来有“唐宋变革论”,强调唐宋之别,但从宰相制度来看,唐宋历史的联系性似乎更突出。

关键词：唐代政事堂中书门下首相制