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Nucleus-targeted Dmp1 transgene fails to rescue dental defects in Dmp1 null mice

International Journal of Oral Science 2014年第3期6卷 133-141页

作者： Shu-Xian Lin Qi Zhang Hua Zhang kevin yan Leanne Ward Yong-Bo Lu Jian-Quan Feng Department of Biomedical Sciences Texas A&M University Baylor College of Dentistry The State Key Laboratory Breeding Base of Basic Science of Stomatology(Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education School & Hospital of Stomatology Wuhan University Laboratory of Oral Biomedical Science and Translational Medicine Department of Endodontics School of Stomatology Tongji University Department of Biological Sciences Columbia University Children’s Hospital of Eastern Ontario University of Ottawa

Dentin matrix protein 1（DMP1） is essential to odontogenesis. Its mutations in human subjects lead to dental problems such as dental deformities, hypomineralization and periodontal impairment. Primarily, DMP1 is considered as an extracellular matrix protein that promotes hydroxyapatite formation and activates intracellular signaling pathway via interacting with avb3 integrin. Recent in vitro studies suggested that DMP1 might also act as a transcription factor. In this study, we examined whether full-length DMP1 could function as a transcription factor in the nucleus and regulate odontogenesis in vivo. We first demonstrated that a patient with the DMP1M1 V mutation, which presumably causes a loss of the secretory DMP1 but does not affect the nuclear translocation of DMP1, shows a typical rachitic tooth defect. Furthermore, we generated transgenic mice expressingNLSDMP1, in which the endoplasmic reticulum（ER） entry signal sequence of DMP1 was replaced by a nuclear localization signal（NLS） sequence, under the control of a 3.6 kb rat type I collagen promoter plus a 1.6 kb intron 1. We then crossbred theNLSDMP1 transgenic mice with Dmp1 null mice to express the NLSDMP1 in Dmp1-deficient genetic background. Although immunohistochemistry demonstrated thatNLSDMP1 was localized in the nuclei of the preodontoblasts and odontoblasts, the histological, morphological and biochemical analyses showed that it failed to rescue the dental and periodontal defects as well as the delayed tooth eruption in Dmp1 null mice. These data suggest that the full-length DMP1 plays no apparent role in the nucleus during odontogenesis.

关键词： autosomal recessive hypophosphatemic rickets dentin matrix protein 1 development odontoblast odontogenesis

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基于加压毛细管电色谱-激光诱导荧光联用技术研究离子强度对维生素B2光解反应的影响

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色谱 2018年第4期36卷 381-387页

作者：肖汉 kevin yan 郑怡婷王彦阎超上海交通大学药学院上海200240 University of California Riverside 92521USA

基于加压毛细管电色谱-激光诱导荧光检测法建立了分析维生素B2及其荧光性光解产物的方法,并用于研究维生素B2在水溶液和磷酸盐缓冲液中的光解反应速率与离子强度之间的关系。发现在C18毛细管色谱柱,流动相为含0.1%(v/v)三氟乙酸的乙腈... 详细信息

基于加压毛细管电色谱-激光诱导荧光检测法建立了分析维生素B2及其荧光性光解产物的方法,并用于研究维生素B2在水溶液和磷酸盐缓冲液中的光解反应速率与离子强度之间的关系。发现在C18毛细管色谱柱,流动相为含0.1%(v/v)三氟乙酸的乙腈水溶液,梯度洗脱,激发波长为488 nm,发射波长为520 nm的条件下,维生素B2及多种荧光性光解产物均得到很好的分离和检测,维生素B2的定量限为5×10-8mol/L。在此基础上研究了维生素B2的光降解反应受光照时间和离子强度等的影响。发现离子强度对维生素B2溶液的光解反应有显著影响,离子强度越大,光解速度越快。并进一步通过动力学计算得到维生素B2在水溶液和磷酸盐缓冲液中光解反应的表观速率常数。该研究为维生素B2的光稳定研究提供了一种高效分离和检测的方法,并为维生素B2的保存及临床使用提供了参考。

关键词：加压毛细管电色谱激光诱导荧光检测维生素B2 光解反应反应速率常数

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从BRDF到BPDF:遥感反演基础模型的演进初探

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中国科学：信息科学 2024年第8期54卷 2001-2020页

作者：尚可晏磊张飞舟褚君浩杨彬刘思远 kevin TANSEY 贾秀萍 Oleg DUBOVIK 张子晗李飞北京大学地球与空间科学学院遥感与地理信息系统研究所北京大学空间信息集成与3S工程应用北京市重点实验室北京100871 中国科学院上海技术物理研究所红外物理国家重点实验室上海200083 湖南大学电气与信息工程学院长沙410082 中国兵器工业导航与控制技术研究所北京100089 School of Geography Geologyand the EnvironmentUniversity of LeicesterLeicester LE17RHUK School of Engineering and Technology The University of New South WalesCanberra ACT 2600Australia Laboratoire d'Optique Atmospherique CNRS/UniversitéLilleVilleneuve d'Ascq 59655France

光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感... 详细信息

光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感基础上考虑垂直于电磁波传播方向的二维偏振矢量特性(强度+方向)就能深化为矢量遥感体系,从而有望精确刻画反射光中蕴含的多种信息,提升植被参数反演精度.刻画偏振反射空间分布的双向偏振分布函数BPDF目前存在精度低、泛化性差等问题,因此进一步探索矢量遥感基础理论,构建通用性强的植被矢量遥感基础模型具有迫切的现实需求.本文旨在利用光子与植被元素的相互作用构建通用性较强的植被BPDF物理模型.首先基于光子–植被元素相互作用的光谱不变原理,提出基于方向逃逸概率的植被BPDF物理模型基础形式,并基于植被单次反射的辐射传输理论推导模型解析表达;随后通过考虑叶片散射随干物质含量的变化,提出光谱不变原理优化表达并推导模型通用表达式;最后分别利用三维矢量辐射传输模型和多尺度实测数据实现模型的正演直接验证和间接验证.结果表明,本文构建的BPDF物理模型的解析表达和通用表达在不同植被场景下,对偏振反射率的正演均方根误差可达0.001以内,与矢量辐射传输模型正演结果在半球空间内具有很强一致性,在多尺度实测数据也简洁验证了模型关系的稳定性,模型R2普遍高于0.9.相比于现存植被偏振反射模型,本文构建的模型兼具物理机理、简洁形式、可接受的参数化方案、较高精度和较强泛化能力,对浓密植被具备通用性,为在BRDF一维标量遥感的基础上进一步考虑BPDF二维偏振特性从而形成矢量遥感体系这一转变过程提供了理论基础和探索性方案.

关键词：植被 BPDF 矢量遥感物理模型偏振

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Influence of 3d transition-metal substitution on the oxygen reduction reaction electrocatalysis of ternary nitrides in acid

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Nano Research 2019年第9期12卷 2307-2312页

作者： kevin E. Fritz Yichen yan Jin Suntivich Department of Material Science and Engineering Cornell UniversityIthacaNew York 14850USA Kavli Institute at Cornell for Nanoscale Science IthacaNew York 14850USA

The development of non-precious,acid-stable,oxygen reduction reaction(ORR)electrocatalysts can significantly aid the commercialization of proton exchange membrane fuel cells(PEMFCs).We report a survey of the ORR electrocatalysis on 3d metal substituted(M=Mn,Fe,Co)molybdenum and tungsten nitrides in acidic *** find that molybdate catalysts are more active than tungstates,with the specific activity depending on the chemistry of the substituted 3d *** both families,more electronegative 3d metals led to higher ORR activity(i.e.,Co>Fe>Mn).We attribute this result to the ability of the more electro negative 3d metal to withdraw electro ns from the Mo-or W-based active sites,effectively oxidizing the metal centers of the *** on our observation,future nitride ORR electrocatalysts can be further optimized by oxidizing the Mo sites further by,for example,addi ng eve n more electro negative dopa nt metals or in corporati ng anion vaca ncies.

关键词： nitrides electrocatalysis fuel cells oxygen reduction

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Heterogeneity and non-linearity of ecosystem responses to climate change in the Qilian Mountains National Park, China

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Journal of Arid Land 2023年第5期15卷 508-522页

作者： GAO Xiang WEN Ruiyang kevin LO LI Jie yan An College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China Department of Geography Hong Kong Baptist UniversityHong Kong 999077China

Ecosystem responses to climate change,particularly in arid environments,is an understudied *** study conducted a spatial analysis of ecosystem responses to short-term variability in temperature,precipitation,and solar radiation in the Qilian Mountains National Park,an arid mountainous region in Northwest *** collected precipitation and temperature data from the National Science and Technology Infrastructure Platform,solar radiation data from the China Meteorological Forcing Dataset,and vegetation cover remote-sensing data from the Moderate Resolution Imaging *** used the vegetation sensitivity index to identify areas sensitive to climate change and to determine which climatic factors were significant in this *** findings revealed a high degree of heterogeneity and non-linearity of ecosystem responses to climate *** types of heterogeneity were identified:longitude,altitude,ecosystem,and climate ***,the characteristics of nonlinear ecosystem responses to climate change included:(1)inconsistency in the controlling climatic factors for the same ecosystems in different geographical settings;(2)the interaction between different climatic factors results in varying weights that affect ecosystem stability and makes them difficult to determine;and(3)the hysteresis effect of vegetation increases the uncertainty of ecosystem responses to climate *** findings are significant because they highlight the complexity of ecosystem responses to climate ***,the identification of areas that are particularly sensitive to climate change and the influencing factors has important implications for predicting and managing the impacts of climate change on ecosystems,which can help protect the stability of ecosystems in the Qilian Mountains National Park.

关键词： ecosystem resistance ecosystem stability climate change vegetation sensitivity index(VSI) Qilian Mountains National Park

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EDA: an enhanced dual-active algorithm for location privacy preservation in mobile P2P networks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第5期14卷 356-373页

作者： yan-zhe CHE kevin CHIEW Xiao-yan HONG Qiang yanG Qin-ming HE College of Computer Science and Technology Zhejiang University School of Engineering Tan Tao University Department of Computer Science University of Alabama College of Electrical Engineering Zhejiang University

Various solutions have been proposed to enable mobile users to access location-based services while preserving their location privacy. Some of these solutions are based on a centralized architecture with the participation of a trustworthy third party, whereas some other approaches are based on a mobile peer-to-peer (P2P) architecture. The former approaches suffer from the scalability problem when networks grow large, while the latter have to endure either low anonymization success rates or high communication overheads. To address these issues, this paper deals with an enhanced dual-active spatial cloaking algorithm (EDA) for preserving location privacy in mobile P2P networks. The proposed EDA allows mobile users to collect and actively disseminate their location information to other users. Moreover, to deal with the challenging characteristics of mobile P2P networks, e.g., constrained network resources and user mobility, EDA enables users (1) to perform a negotiation process to minimize the number of duplicate locations to be shared so as to significantly reduce the communication overhead among users, (2) to predict user locations based on the latest available information so as to eliminate the inaccuracy problem introduced by using some out-of-date locations, and (3) to use a latest-record-highest-priority (LRHP) strategy to reduce the probability of broadcasting fewer useful locations. Extensive simulations are conducted for a range of P2P network scenarios to evaluate the performance of EDA in comparison with the existing solutions. Experimental results demonstrate that the proposed EDA can improve the performance in terms of anonymity and service time with minimized communication overhead.

关键词： Location-based service Privacy preservation Spatial cloaking Mobile peer-to-peer networks

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Residential building performance analysis at near extreme weather conditions in Hong Kong through a thermal-comfort-based strategy

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Building Simulation 2023年第1期16卷 13-25页

作者： K.F.Fong C.K.Lee kevin Ka-Lun Lau Edward yan Yung Ng Division of Building Science and Technology College of EngineeringCity University of Hong KongHong KongChina Department of Civil Engineering and Natural Resources Lulea University of TechnologySweden School of Architecture The Chinese University of Hong KongHong KongChina

The precise building performance assessment of residential housings in subtropical regions is usually more difficult than that for the commercial premises due to the much more complicated behavior of the occupants with regard to the change in indoor *** conventional use of a fixed schedule for window opening,clothing insulation and cooling equipment operation cannot reflect the real situation when the occupants respond to the change in thermal comfort,thus affecting the appropriateness of the assessment *** rectify the situation,a new modeling strategy in which the modification of the various operation schedules was based on the calculated thermal comfort(TC),was developed in this *** this new TC-based strategy,the realistic building performances under different cooling provision scenarios applied to a high-rise residential building under the near extreme weather conditions were investigated and *** was found that sole provision of ventilation fans could not meet the zone thermal comfort by over 68%of the time,and air-conditioning was *** optimal use of ventilation fans for cooling could only help reduce the total cooling energy demand by less than 12%at best which could only be realistically evaluated by adopting the present *** studies were conducted which revealed that some design factors could offer opportunities for reducing the total cooling energy under the near extreme weather conditions.

关键词： predicted mean vote thermal comfort ventilation potential building performance simulation residential housings

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KDM2B promotes cell viability by enhancing DNA damage response in canine hemangiosarcoma

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Journal of Genetics and Genomics 2021年第7期48卷 618-630页

作者： kevin Christian Montecillo Gulay Keisuke Aoshima Yuki Shibata Hironobu Yasui Qin yan Atsushi Kobayashi Takashi Kimura Laboratory of Comparative Pathology Department of Clinical SciencesFaculty of Veterinary MedicineHokkaido UniversitySapporoHokkaido 060-0818 Japan Laboratory of Radiation Biology Department of Applied Veterinary SciencesFaculty of Veterinary MedicineHokkaido UniversitySapporoHokkaido 060-0818 Japan Department of Pathology Yale School of MedicineNew HavenCT 06510USA

Epigenetic regulators have been implicated in tumorigenesis of many types of cancer;however,their roles in endothelial cell cancers such as canine hemangiosarcoma(HSA)have not been *** this study,we find that lysine-specific demethylase 2 b(KDM2 B)is highly expressed in HSA cell lines compared with normal canine endothelial *** of KDM2 B in HSA cells results in increased cell death in vitro compared with the scramble control by inducing apoptosis through the inactivation of the DNA repair pathways and accumulation of DNA ***,doxycycline-induced KDM2 B silencing in tumor xenografts results in decreased tumor sizes compared with the ***,KDM2 B is also highly expressed in clinical cases of *** hypothesize that pharmacological KDM2 B inhibition can also induce HSA cell death and can be used as an alternative treatment for *** treat HSA cells with GSK-J4,a histone demethylase inhibitor,and find that GSK-J4 treatment also induces apoptosis and cell *** addition,GSK-J4 treatment decreases tumor ***,we demonstrate that KDM2 B acts as an oncogene in HSA by enhancing the DNA damage ***,we show that histone demethylase inhibitor GSK-J4 can be used as a therapeutic alternative to doxorubicin for HSA treatment.

关键词： DNA repair Epigenetics Hemangiosarcoma KDM2B Oncogene

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Long-term improvements in water conservation functions at Qilian Mountain National Park, northwest China

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Journal of Mountain Science 2023年第10期20卷 2885-2897页

作者： GAO Xiang HUANG Xing-xing CHANG Shu-hang DANG Qian-wen WEN Rui-yang LO kevin LI Jie yan An College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China Department of Geography Hong Kong Baptist UniversityHong Kong 999077China

Water conservation is one of the most important ecosystem *** study uses the InVEST model to examine the water conservation function of the Qilian Mountain National Park(QMNP),an important water supply area in northwest *** analyzed the spatiotemporal water conservation patterns of QMNP from 1988 to *** showed that the water conservation capacity in QMNP has increased over the past 32 years,reaching a peak of 6.495×108 m3 in *** area with an increased water conservation capacity is 12 times larger than the area with a reduced *** also examined how climatic,land-use,vegetation coverage,and topographical factors influence water conservation *** found that precipitation is the main climatic factor in water *** water conservation function also varies with land-cover type,with forests having the highest capacity,followed by ***,topographical factors,including altitude and slope,also shape the spatial patterns of water conservation functions in QMNP.

关键词： Water conservation function Ecosystem services InVEST model Qilian Mountain National Park Northwest China

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Incomplete reproductive isolation between Rhododendron taxa enables hybrid formation and persistence

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Journal of Integrative Plant Biology 2019年第4期61卷 433-448页

作者： Li-Jun yan kevin S.Burgess Wei Zheng Zhi-Bin Tao De-Zhu Li Lian-Ming Gao Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany the Chinese Academy of Sciences Germplasm Bank of Wild Species Kunming Institute of Botany the Chinese Academy of Sciences Kunming College of Life Science University of the Chinese Academy of Sciences College of Vocational and Technical Education Yunnan Normal University Department of Biology College of Letters & Sciences Columbus State University University System of Georgia

The evolutionary consequences of hybridization ultimately depend on the magnitude of reproductive isolation between hybrids and their parents. We evaluated the relative contributions of pre-and post-zygotic barriers to reproduction for hybrid formation, hybrid persistence and potential for reproductive isolation of hybrids formed between two Rhododendron species,R. spiciferum and R. spinuliferum. Our study established that incomplete reproductive isolation promotes hybrid formation and persistence and delays hybrid *** pre-zygotic barriers to reproduction leading to hybrid formation are incomplete: parental species have overlapping flowering; they share the same pollinators;reciprocal assessments of pollen tube germination and growth do not differ among parents. The absence of post-zygotic barriers between parental taxa indicates that the persistence of hybrids is likely. Reproductive isolation was incomplete between hybrids and parents in all cases studied, although asymmetric differences in reproductive fitness were prevalent and possibly explain the genetic structure of natural hybrid swarms where hybridization is known to be bidirectional but asymmetric. Introgression, rather than speciation, is a probable evolutionary outcome of hybridization between the two Rhododendron taxa. Our study provides insights into understanding the evolutionary implications of natural hybridization in woody plants.

关键词： Incomplete reproductive isolation Rhododendron taxa

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