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Aged hematopoietic stem cells entrap regulatory T cells to create a prosurvival microenvironment

Cellular & Molecular Immunology 2023年第10期20卷 1216-1231页

作者： Weinian Liao Chaonan Liu Ke Yang Jun Chen yiding Wu Shuzhen Zhang Kuan Yu Lisha Wang Li Ran Mo Chen Fang Chen Yang Xu Song Wang Fengchao Wang Qian Zhang Jinghong zhao Lilin Ye Changhong Du Junping Wang State Key Laboratory of Trauma Burnsand Combined InjuryInstitute of Combined InjuryChongqing Engineering Research Center for NanomedicineCollege of Preventive MedicineArmy Medical University(Third Military Medical University)400038ChongqingChina Department of Nephrology The Key Laboratory for the Prevention and Treatment of Chronic Kidney Disease of ChongqingKidney Center of PLAXinqiao HospitalArmy Medical University(Third Military Medical University)400037ChongqingChina Institute of Immunology Army Medical University(Third Military Medical University)400038ChongqingChina National Key Laboratory of Medical Immunology Institute of ImmunologyNaval Medical University200433ShanghaiChina

Although DNA mutation drives stem cell aging,how mutation-accumulated stem cells obtain clonal advantage during aging remains poorly ***,using a mouse model of irradiation-induced premature aging and middle-aged mice,we show that DNA mutation accumulation in hematopoietic stem cells(HSCs)during aging upregulates their surface expression of major histocompatibility complex class II(MHCII).MHCII upregulation increases the chance for recognition by bone marrow(BM)-resident regulatory T cells(Tregs),resulting in their clonal expansion and accumulation in the HSC *** the basis of the establishment of connexin 43(Cx43)-mediated gap junctions,BM Tregs transfer cyclic adenosine monophosphate(cAMP)to aged HSCs to diminish apoptotic priming and promote their survival via activation of protein kinase A(PKA)***,targeting the HSC–Treg interaction or depleting Tregs effectively prevents the premature/physiological aging of *** findings show that aged HSCs use an active self-protective mechanism by entrapping local Tregs to construct a prosurvival niche and obtain a clonal advantage.

关键词： Hematopoietic stem cell regulatory T cell Aging

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Comparison between ionospheric peak parameters retrieved from COSMIC measurement and ionosonde observation over Sanya

Comparison between ionospheric peak parameters retrieved fro...

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中国科学院地质与地球物理研究所2014年度（第14届）学术年会

作者： Lianhuan Hu Baiqi Ning Libo Liu Biqiang zhao yiding Chen Guozhu Li Institute of Geology and Geophysics Chinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and Geophysics Chinese Academy of Sciences University of Chinese Academy of Sciences

In this paper we compared the ionospheric peak parameters(peak electron density of the F region, Nm F2, and peak height of the F region, hm F2) retrieved from the FORMASAT-3/COSMIC(COSMIC for short) satellite measurement with those from ionosonde observation at Sanya(18.3°N, 109.6°E) during the period of 2008–2013. Although COSMIC Nm F2(hm F2) tends to be lower(higher)than ionosonde Nm F2(hm F2), the results show that the ionospheric peak parameters retrieved from COSMIC measurement generally agree well with ionosonde observation. For Nm F2 the correlation between the COSMIC measurement and the ionosonde observation is higher than 0.89, and for hm F2 the correlation is higher than 0.80. The correlation of the ionospheric peak parameters decreases when solar activity increases. The performance of COSMIC measurement is acceptable under geomagnetic disturbed condition. The correlation of Nm F2 between COSMIC and ionosonde measurements is higher(lower) during the nighttime(daytime), while the correlation of hm F2 is lower(higher) during the nighttime(daytime).

关键词： COSMIC Radio occultation Ionosonde Nm F2 hm F2

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Slow-light-enhanced on-chip 1D and 2D photonic crystal waveguide gas sensing in near-IR with an ultrahigh interaction factor

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Photonics Research 2023年第10期11卷 1647-1656页

作者： ZIHANG PENG YIJUN HUANG KAIYUAN ZHENG CHUANTAO ZHENG MINGQUAN PI HUAN zhao JIALIN JI YUTING MIN LEI LIANG FANG SONG YU ZHANG yiding WANG FRANK K.TITTEL State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China Department of Electrical Engineering and Photonics Research Institute The Hong Kong Polytechnic UniversityHong Kong 518060China State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Department of Electrical and Computer Engineering Rice UniversityHoustonTexas 77005USA

Nanophotonic waveguides hold great promise to achieve chip-scale gas sensors. However, their performance is limited by a short light path and small light–analyte overlap. To address this challenge, silicon-based, slow-lightenhanced gas-sensing techniques offer a promising approach. In this study, we experimentally investigated the slow light characteristics and gas-sensing performance of 1D and 2D photonic crystal waveguides(PCWs) in the near-IR(NIR) region. The proposed 2D PCW exhibited a high group index of up to 114, albeit with a high propagation loss. The limit of detection(LoD) for acetylene(C_(2)H_(2)) was 277 parts per million(ppm) for a1 mm waveguide length and an averaging time of 0.4 s. The 1D PCW shows greater application potential compared to the 2D PCW waveguide, with an interaction factor reaching up to 288%, a comparably low propagation loss of 10 dB/cm, and an LoD of 706 ppm at 0.4 s. The measured group indices of the 2D and 1D waveguides are104 and 16, respectively, which agree well with the simulation results.

关键词： waveguide light interaction

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The ionospheric anomalies prior to the M9.0 Tohoku-Oki earthquake

The ionospheric anomalies prior to the M9.0 Tohoku-Oki earth...

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中国科学院地质与地球物理研究所2013年度（第13届）学术年会

作者： Huijun Le Libo Liu Jann-Yeng Liu Biqiang zhao yiding Chen Weixing Wan Key Laboratory of Ionospheric Environment Institute of Geology and GeophysicsChinese Academy of Sciences National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences Institute of Space Science National Central University

The GPS total electron content(TEC) data were used to investigate the ionospheric abnormal behaviors prior to the 2011 Tohoku-Oki *** observations show a significant enhancement in TEC on March 8,2011,and during the same period the solar activity also has a large *** an empirical model and a theoretical model were used to check whether the TEC anomalies were entirely contributed by the increase in solar *** comparison between the observations and the simulation results shows that only the solar radiation enhancement was not enough to produce the observed significant TEC *** means that some additional mechanisms,such as the per-earthquake ionospheric disturbance or the geomagnetic activities,may play a significant role in the significant TEC enhancement on March *** temporal-spatial distribution of the extreme TEC enhancement within 30 days before the earthquake was particularly *** is found that the extreme enhancement was persistently located in the region adjacent to the epicenter and the magnetic conjugate point for a long time of 16 *** addition, a geomagnetic disturbance with Kp = 4 occurred on March ***,the significant TEC enhancement on March 8 might be related to the M9.0 Tohoku-Oki earthquake and the geomagnetic disturbance.

关键词： Ionosphere Total electron content Seismo-ionospheric anomaly

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The long-duration positive storm effects in the equatorial ionosphere over Jicamarca

The long-duration positive storm effects in the equatorial i...

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中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Jiawei Kuai Libo Liu Jing Liu Biqiang zhao yiding Chen Huijun Le Weixing Wan Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences University of Chinese Academy of Sciences

The long-duration positive storm(LPS) in the equatorial regions is relatively poorly *** this report,we conducted a statistical analysis of the LPS effects in the equatorial ionosphere over Jicamarca(12.0°S,283.2°E) in 1998–*** are 250 geomagnetic storms(minimum Dst < 50 n T) in1998–2010,but the ionosonde observations at Jicamarca are available only for 204 storms.A total of46 LPSs are identified in terms of the criterion that the storm time relative deviation of peak density of Flayer(NF) exceeds 25% for more than 6 h.A salient feature is that the occurrence of LPSs tends to decay approximately exponentially on the following days after the main phase of geomagnetic *** ratios of the number of equatorial LPSs to that of geomagnetic storms have no obvious dependence on season and solar *** the daytime LPSs,the disturbed zonal electric field is mostly westward,as indicated from the geomagnetic field changes in the equatorial American *** the nighttime LPSs,the significant uplifting of F layer caused by an eastward electric field is the most important ***,the disturbed electric field should play an essential role in forming the equatorial LPSs.

关键词： A statistical analysis to the longduration positive storm(LPS) effects over Jicamarca The occurrence of LPSs decays approximately exponentially after the main phase of the geomagnetic storms The disturbed electric field plays an essential role during the equatorial LPSs

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Modeling the global NmF2 from the GNSS- derived TEC-GIMs

Modeling the global NmF2 from the GNSS- derived TEC-GIMs

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中国科学院地质与地球物理研究所2013年度（第13届）学术年会

作者： You Yu Weixing Wan Biqiang zhao yiding Chen Bo Xiong Libo Liu Jing Liu Zhipeng Ren Ming Li Key Laboratory of Ionospheric Environment Institute of Geology and GeophysicsChinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences University of Chinese Academy of Sciences Department of Mathematics and Physics North China Electric Power University

[1]Based on canonical correlation analysis(CCA),we propose a technique to map the peak electron density of the ionospheric F2-layer(NmFl) from the global observations of the total electron content(TEC). We first statistically analyze the canonical correlation between NmFl and TEC using the NmFl observations of the worldwide ionosonde stations and global ionospheric maps(GIMs) of TEC(TEC-GIMs) provided by the Jet Propulsion *** obtained CCA modes consist of the CCA patterns and corresponding amplitudes,which separately reflect the short-term(e.g.,diurnal variation) and long-term(e.g.,annual, semiannual variations,and solar-cycle variations,etc.) tendencies of *** the obtained CCA patterns and corresponding amplitudes,we then construct two TEC-derived models of the monthly median NmFl,a single station model at Boulder(105.3°W,40°N) and a global *** CCA results are further compared with the observations and corresponding NmFl predictions of the International

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利用太阳方位进行磁偏角测量的探讨

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东南大学学报（自然科学版） 2013年第A2期43卷 307-311页

作者：赵俊生刘强刘雁春王一丁海军大连舰艇学院海洋测绘系大连116018

为了有效提高磁偏角测量精度,解决偏远小岛难以设置方位点的问题,介绍了磁偏角概念和利用GPS测量方位角测定磁偏角的原理,阐述了由测站经纬度、观测时间计算太阳方位角的公式,分析了测站坐标、观测时间等误差对太阳方位角计算的精度影响... 详细信息

为了有效提高磁偏角测量精度,解决偏远小岛难以设置方位点的问题,介绍了磁偏角概念和利用GPS测量方位角测定磁偏角的原理,阐述了由测站经纬度、观测时间计算太阳方位角的公式,分析了测站坐标、观测时间等误差对太阳方位角计算的精度影响.初步论证了利用太阳方位角测量磁偏角时,观测时段选取、测站坐标观测精度要求、测量时刻观测精度要求等问题.设计了依托太阳方位角测量磁偏角的观测方法并给出了检验太阳方位角观测精度的观测实例.对比结果表明:利用太阳方位角进行磁偏角测量可以有效地解决偏远小岛难以设置方位点的问题,并提出了精确的测定测站坐标和观测时间可以有效提高磁偏角测量精度的结论.

关键词：磁偏角太阳方位角天文定位观测实例

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CRTSⅠ型双块式无砟轨道轨排框架法施工影响因素

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铁道建筑 2018年第12期58卷 108-111页

作者：熊飞赵坪锐帅一丁西南交通大学高速铁路线路工程教育部重点实验室四川成都610031 中铁二局集团有限公司四川成都610031

CRTSⅠ型双块式无砟轨道在道床板施工过程中,轨排结构各部件的微小定位偏差将导致轨道几何形位不平顺,增加后期精调工作量。根据轨排框架法施工特点,建立有限元模型,分析道床混凝土浇筑之前的轨道几何形位变化,研究不同轨排支撑间距和... 详细信息

CRTSⅠ型双块式无砟轨道在道床板施工过程中,轨排结构各部件的微小定位偏差将导致轨道几何形位不平顺,增加后期精调工作量。根据轨排框架法施工特点,建立有限元模型,分析道床混凝土浇筑之前的轨道几何形位变化,研究不同轨排支撑间距和部分支撑失效对轨排框架法的影响。结果表明:在自重作用下,当轨排支撑间距增大到7倍扣件间距时,轨面高低值超限,建议施工时支撑间距不宜超过6倍扣件间距;当支撑间距为3倍扣件间距时,单个轨向锁定器失效和单个螺柱支腿失效对轨排结构的变形和受力状态不会产生太大影响,随失效部件的增多,轨距和轨底坡变化量增大; 2组支撑系统失效时,轨面高低值超限,施工时应严格检查,避免出现此极端失效情况。

关键词：高速铁路 CRTSⅠ型双块式无砟轨道数值计算轨排框架法道床板支撑系统

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掺铪氧化锌红外透明导电薄膜

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光学学报 2021年第20期41卷 224-229页

作者：赵雯媛张梦瑶毕然郑传涛王一丁吉林大学集成光电子学国家重点联合实验室电子科学与工程学院吉林长春130012 吉林省红外气体传感技术工程研究中心吉林长春130012

采用射频磁控溅射法在蓝宝石衬底上制备了Hf:ZnO (HZO)薄膜,研究了氧气流速和退火温度对薄膜微观结构和光电性能的影响。为了提高薄膜的结晶性,将制备的薄膜在800℃下退火30 min,并自然冷却到室温。测试、分析了退火后薄膜的微观结构和... 详细信息

采用射频磁控溅射法在蓝宝石衬底上制备了Hf:ZnO (HZO)薄膜,研究了氧气流速和退火温度对薄膜微观结构和光电性能的影响。为了提高薄膜的结晶性,将制备的薄膜在800℃下退火30 min,并自然冷却到室温。测试、分析了退火后薄膜的微观结构和光电性能。研究发现,随着氧气流速从0增加到0.6 mL/min,薄膜的致密度逐渐增大,电阻率逐渐降低,而当氧气流速继续增大到0.8 mL/min时,薄膜的结晶性恶化,电阻率突然升高。氧气流速为0.6 mL/min时制备的薄膜光电性能最佳,利用傅里叶红外光谱仪和霍尔测试仪进行测试,得到薄膜在3~5μm波段的平均透过率为83.87%,电阻率为1.66×10^(-2)Ω·cm,载流子迁移率为13.4 cm^(2)·V^(-1)·s^(-1),载流子浓度为2.82×10^(19) cm^(-3)。利用X射线衍射仪进行测试,发现薄膜样品具有ZnO的六方纤锌矿结构,并沿(002)方向择优生长,通过扫描电子显微镜可以看到薄膜表面生成致密均匀的球状结构颗粒。这种薄膜可以用作3~5μm波段的透明窗口。

关键词：薄膜磁控溅射中红外波段透明导电薄膜氧化锌 Hf:ZnO

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空间约束标识点过程的机载激光雷达景观树提取

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激光与光电子学进展 2022年第8期59卷 396-405页

作者：陈红月赵泉华李玉王一丁辽宁工程技术大学测绘与地理科学学院辽宁阜新123000 辽宁工程技术大学环境科学与工程学院辽宁阜新123000

针对目前关于城区景观树提取存在的提取精度低、数据代表性不足、算法复杂等问题,提出了一种空间约束标识点过程的机载激光雷达(LiDAR)景观树提取方法。所提方法从点云数据中分离非地面点,且通过树冠点云密度约束标识点过程模型。首先,... 详细信息

针对目前关于城区景观树提取存在的提取精度低、数据代表性不足、算法复杂等问题,提出了一种空间约束标识点过程的机载激光雷达(LiDAR)景观树提取方法。所提方法从点云数据中分离非地面点,且通过树冠点云密度约束标识点过程模型。首先,采用三角网迭代加密滤波算法将LiDAR点云数据中的地面点与非地面点分离;然后,针对非地面点数据定义景观树空间分布标识点过程模型,以圆形刻画景观树在地面投影区域的几何形状,定义树冠投影区几何模型,并结合景观树和非树区域数据点的高程分布特点构建高程分布模型;在此基础上,根据树冠点云的空间密度特征,构建高程约束模型;在贝叶斯理论架构下综合上述模型建立景观树提取模型,并结合可逆跳变马尔可夫链蒙特卡罗算法模拟该提取模型;最后,根据最大后验概率准则,获取最优景观树提取结果。实验结果表明,所提方法提取的景观树整体精度较高,总体的提取率和正确率均达到了90%以上,对识别难度较大的复杂场景景观树提取结果亦能达到较高精度。

关键词：机载激光雷达景观树提取标识点过程高程约束模型可逆跳变马尔可夫链蒙特卡罗

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