检索结果-南通市图书馆

Trees species’ dispersal mode and habitat heterogeneity shape negative density dependence in a temperate forest

森林生态系统:英文版 2023年第5期10卷 589-596页

作者： Lishunan yang Daniel J.Johnson Zhichun yang xiaochao yang Qiulong Yin Ying Luo Zhanqing Hao Shihong Jia School of Ecology and Environment Northwestern Polytechnical UniversityXi’anShaanxi710072China Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection Northwestern Polytechnical UniversityXi’anShaanxi710072China School of Forest Fisheriesand Geomatics SciencesUniversity of FloridaGainesvilleFLUSA School of Geography and Tourism Shaanxi Normal UniversityXi’anShaanxi710062China

Conspecific negative density dependence(CNDD)is a potentially important mechanism in maintaining species diversity.While previous evidence showed habitat heterogeneity and species’dispersal modes affect the strength of CNDD at early life stages of trees(e.g.,seedlings),it remains unclear how they affect the strength of CNDD at later life stages.We examined the degree of spatial aggregation between saplings and trees for species dispersed by wind and gravity in four topographic habitats within a 25-ha temperate forest dynamic plot in the Qinling Mountains of central China.We used the replicated spatial point pattern(RSPP)analysis and bivariate paircorrelation function(PCF)to detect the spatial distribution of saplings around trees at two scales,15 and 50 m,respectively.Although the signal was not apparent across the whole study region(or 25-ha),it is distinct on isolated areas with specific characteristics,suggesting that these characteristics could be important factors in CNDD.Further,we found that the gravity-dispersed tree species experienced CNDD across habitats,while for wind-dispersed species CNDD was found in gully,terrace and low-ridge habitats.Our study suggests that neglecting the habitat heterogeneity and dispersal mode can distort the signal of CNDD and community assembly in temperate forests.

关键词： Biodiversity Conspecific negative density dependence Dispersal Replicated point patterns Temperate forest Topographic habitat

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Central nervous system injury meets nanoceria:opportunities and challenges

引用

Regenerative Biomaterials 2022年第1期9卷 1001-1017页

作者： Wang yang Maoting Zhang Jian He Mingfu Gong Jian Sun xiaochao yang School of Biomedical Engineering and Medical Imaging Army Medical UniversityChongqing 400038China Army Health Service Training Base Army Medical UniversityChongqing 400038China Xinqiao Hospital Army Medical UniversityChongqing 400038China

Central nervous system(CNS)injury,induced by ischemic/hemorrhagic or traumatic damage,is one of the most common causes of death and long-term disability worldwide.Reactive oxygen and nitrogen species(RONS)resulting in oxidative/nitrosative stress play a critical role in the pathological cascade of molecular events after CNS injury.Therefore,by targeting RONS,antioxidant therapies have been intensively explored in previous studies.However,traditional antioxidants have achieved limited success thus far,and the development of new antioxidants to achieve highly effective RONS modulation in CNS injury still remains a great challenge.With the rapid development of nanotechnology,novel nanomaterials provided promising opportunities to address this challenge.Within these,nanoceria has gained much attention due to its regenerative and excellent RONS elimination capability.To promote its practical application,it is important to know what has been done and what has yet to be done.This review aims to present the opportunities and challenges of nanoceria in treating CNS injury.The physicochemical properties of nanoceria and its interaction with RONS are described.The applications of nanoceria for stroke and neurotrauma treatment are summarized.The possible directions for future application of nanoceria in CNS injury treatment are proposed.

关键词： nanoceria reactive oxygen species central nervous system injury stroke neurotrauma

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bone-targeted pH-responsive cerium nanoparticles for anabolic therapy in osteoporosis

引用

Bioactive Materials 2021年第12期6卷 4697-4706页

作者： Ce Dou Jianmei Li Jian He Fei Luo Tao Yu Qijie Dai Yueqi Chen Jianzhong Xu xiaochao yang Shiwu Dong Department of Orthopedics Southwest HospitalThird Military Medical University(Army Medical University)Chongqing400038China Department of Biomedical Materials Science Third Military Medical University(Army Medical University)Chongqing400038China State Key Laboratory of Trauma Burns and Combined InjuryThird Military Medical University(Army Medical University)Chongqing400038China

Antiresorptive drugs are widely used for treatment of osteoporosis and cancer bone metastasis,which function mainly through an overall inhibition of osteoclast.However,not all osteoclasts are“bone eaters”;preosteoclasts(pOCs)play anabolic roles in bone formation and angiogenesis through coupling with osteoblasts and secreting platelet derived growth factor-BB(PDGF-BB).In this study,a bone-targeted pH-responsive nanomaterial was designed for selectively eliminating mature osteoclasts(mOCs)without affecting pOCs.Biocompatible cerium nano-system(CNS)was guided to the acidic extracellular microenvironment created by mOCs and gained oxidative enzymatic activity.Oxidative CNS decreased the viability of mOCs through accumulating intracellular reactive oxygen species and enhancing calcium oscillation.Non-acid secreting anabolic pOCs were thus preserved and kept producing PDGF-BB,which lead to mesenchymal stem cell osteogenesis and endothelial progenitor cell angiogenesis via PI3K-Akt activated focal adhesion kinase.In treating osteoporotic ovariectomized mice,CNS showed better protective effects compare with the current first line antiresorptive drug due to the better anabolic effects marked by higher level of bone formation and vascularization.We provided a novel anabolic therapeutic strategy in treating bone disorders with excessive bone resorption.

关键词： pH-responsive Nanomedicine Bone Osteoclast Anabolic therapy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Progress of Radiation Belt Exploration by a Constellation of Small Satellites TGCSS/SGRB,COSPAR

引用

空间科学学报 2022年第4期42卷 836-840页

作者： WU Ji yang xiaochao DAI Lei National Space Science Center Chinese Academy of SciencesBeijing 100190

A COnstellation of Radiation BElt Survey(CORBES)program is proposed by the Sub-Group on Radiation Belt(SGRB)of TGCSS,COSPAR.The CORBES mission is expected to have a constellation of 10-plus small/Cube Sats to take an ultra-fast survey of the Earth’s radiation belt.The general science goal for CORBES is to investigate two groups of physical processes related to the radiation belts:wave-particle interactions and radial transport.This mission is an international multilateral cooperation mission,an open and sharing data policy will be implemented.The data set of observations will be shared within the contributors of the constellation and the broad research community at large,then would be of great use for comprehensively understanding the dynamics of magnetospheric energetic populations and developing more standard models of the Earth’s radiation belts.Furthermore,from the application perspective,the ultra-fast survey of the radiation belt could serve as an important facility for monitoring space weather of the Earth as well.

关键词： Radiation belts Ultra-fast survey Constellation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

软塑/流塑软弱土场地光伏支架基础不均匀沉降问题及解决措施

引用

太阳能 2024年第2期 109-114页

作者：阳小超陈少雄何志刚中国能源建设集团湖南省电力设计院有限公司长沙410007

针对光伏支架在软塑/流塑软弱土场地应用时存在的一些问题,提出一种半预制轻型光伏支架基础形式,旨在克服常规基础因受场地限制不适用,或施工难度大、建设成本较高的问题。通过沉降计算分析,在满足软塑/流塑软弱土地基承载力及基础整体... 详细信息

针对光伏支架在软塑/流塑软弱土场地应用时存在的一些问题,提出一种半预制轻型光伏支架基础形式,旨在克服常规基础因受场地限制不适用,或施工难度大、建设成本较高的问题。通过沉降计算分析,在满足软塑/流塑软弱土地基承载力及基础整体稳定性的前提下,该半预制轻型光伏支架基础可以实现安装支架基础上方设施后,不增加基础底面附加压力,从根本上解决了光伏电站建设后场地地基的后续沉降问题。

关键词：光伏支架基础半预制软弱土软塑/流塑不均匀沉降

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Moxibustion of Zusanli(ST36)and Shenshu(BL23)alleviates the inflammation of rheumatoid arthritis in rats through regulating macrophage migration inhibitory factor/glucocorticoids signaling

引用

Journal of Traditional Chinese Medicine 2024年第2期44卷 353-361页

作者： ZHANG Linlin ZHONG Yumei LU Wenting SHANG Yanan GUO Yanding LUO xiaochao CHEN yang LUO Kun HU Danhui YU Huiling ZHOU Haiyan Acupuncture and Moxibustion College Chengdu University of Traditional Chinese MedicineChengdu 610075China Department of Painology First People's Hospital of ChengduChengdu 610095China Chinese Evidence-Based Medicine Centre West China HospitalSichuan UniversityChengdu 610044China Traditional Chinese Medicine College Chongqing Medical UniversityChongqing 400016China External treatment center First People's Hospital of ChengduChengdu 610095China

OBJECTIVE:To test the hypothesis that moxibustion may inhibit rheumatoid arthritis(RA)synovial inflammation by regulating the expression of macrophage migration inhibitory factor(MIF)/glucocorticoids(GCs).METHODS:Fifty male Sprague-Dawley rats were randomly divided into five groups(n=10 each):blank Control(CON)group,RA Model(RA)group,Moxibustion(MOX)group,MIF inhibitor(S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester(ISO-1)group,and Moxibustion+MIF inhibitor ISO-1(MOX+ISO-1)group.Rats in the ISO-1 group and ISO-1+MOX group were intraperitoneally injected with the inhibitor ISO-1.The rats in the RA group,ISO-1 group,MOX group,and ISO-1+MOX group were injected with Freund's complete adjuvant(FCA)in the right hind footpad to establish an experimental RA rat model.In the MOX group and MOX+ISO-1 group,rats were treated with Moxa.The thickness of the footpads of the rats in each group was measured at three-time points before,after modeling and after moxibustion treatment.The contents of serum MIF,corticosterone(CORT),tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)were detected by enzyme-linked immunosorbent assay;and the contents of synovial MIF were detected by Western blot.Hematoxylin-eosin(HE)staining method was used to observe the pathological changes of synovial tissue under a section light microscope,and pathological scoring was performed according to the grading standard of the degree of synovial tissue disease.RESULTS:Moxibustion was found to reduce the level of MIF and alleviate inflammation in RA rats in this study.In addition,after inhibiting the expression of MIF,the level of CORT increased,and the level of TNF-α decreased.Treating RA rats with inhibited MIF by moxibustion,the level of CORT was almost unchanged,but the level of TNF-α further decreased.The correlation analysis data suggested that MIF was positively related to the expression of TNF-α and negatively correlated with the expression of CORT.CONCLUSION:Reducing MIF to increase CORT and decrease TNF-α by moxibustion

关键词： rheumatoid arthritis macrophage migration inhibitory factor moxibustion corticosterone glucocorticoids

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sulfation of chondroitin and bile acids converges to antagonize Wnt/β-catenin signaling and inhibit APC deficiency-induced gut tumorigenesis

引用

Acta Pharmaceutica Sinica B 2024年第3期14卷 1241-1256页

作者： Pengfei Xu Yue Xi Jong-Won Kim Junjie Zhu Min Zhang Meishu Xu Songrong Ren Da yang xiaochao Ma Wen Xie Center for Pharmacogenetics and Department of Pharmaceutical Sciences University of PittsburghPittsburghPA 15261USA Department of Hepatobiliary and Pancreatic Surgery Zhongnan Hospital of Wuhan UniversitySchool of Pharmaceutical SciencesWuhan UniversityWuhan 430071China Department of Pharmacology&Chemical Biology University of PittsburghPittsburghPA 15261USA

Sulfation is a crucial and prevalent conjugation reaction involved in cellular processes and mammalian physiology.3’-Phosphoadenosine 5’-phosphosulfate(PAPS)synthase 2(PAPSS2)is the primary enzyme to generate the universal sulfonate donor PAPS.The involvement of PAPSS2-mediated sulfation in adenomatous polyposis coli(APC)mutation-promoted colonic carcinogenesis has not been reported.Here,we showed that the expression of PAPSS2 was decreased in human colon tumors along with cancer stages,and the lower expression of PAPSS2 was correlated with poor prognosis in advanced colon cancer.Gut epithelial-specific heterozygous Apc deficient and Papss2-knockout(Apc^(Δgut-Het)Papss2^(Δgut))mice were created,and the phenotypes were compared to the spontaneous intestinal tumorigenesis of Apc^(Δgut-Het)mice.Apc^(Δgut-Het)Papss2^(Δgutmice) were more sensitive to gut tumorigenesis,which was mechanistically accounted for by the activation of Wnt/β-catenin signaling pathway due to the suppression of chondroitin sulfation and inhibition of the farnesoid X receptor(FXR)-transducin-like enhancer of split 3(TLE3)gene regulatory axis.Chondroitin sulfate supplementation in Apc^(Δgut-Het)Papss2^(Δgutmice) alleviated intestinal tumorigenesis.In summary,we have uncovered the protective role of PAPSS2-mediated chondroitin sulfation and bile acids-FXR-TLE3 activation in the prevention of gut carcinogenesis via the antagonization of Wnt/β-catenin signaling.Chondroitin sulfate may be explored as a therapeutic agent for Papss2 deficiency-associated colonic carcinogenesis.

关键词： Colon cancer APC Wnt/b-catenin PAPSS2 Chondroitin sulfate Sulfation Bile acids FXR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unusual refilling of the slot region between the Van Allen radiation belts from November 2004 to January 2005

Unusual refilling of the slot region between the Van Allen r...

引用

第34届中国气象学会年会

作者： xiaochao yang Binbin Ni Jiang Yu yang Zhang Xiaoxin Zhang Yueqiang Sun National Space Science Center Chinese Academy of Science Beijing Key Laboratory of Space Environment Exploration Department of Space Physics School of Electronic Information Wuhan University School of Space and Environment Beihang University Key Laboratory of Space Weather National Center for Space Weather

Using multi-satellite measurements, a uniquely strong and long-lived relativistic electron slot region refilling event from November 2004 to January 2005 is investigated. This event occurred under rem

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Double-characters detection of nonlinear frequency modulated signals based on FRFT

引用

Science China(Information Sciences) 2011年第1期54卷 136-145页

作者： XU ShuWen,SHUI PengLang & yang xiaochao National Laboratory of Radar Signal Processing,Xidian University,Xi’an 710071,China National Laboratory of Radar Signal Processing Xidian University Xi’an China

In many practical applications,signals to be detected are unknown nonlinear frequency modulated (FM)and are corrupted by strong noise.The phase histories of the nonlinear FM signals are assumed to be unknown smooth functions of time,which are usually poorly modeled or cannot be modeled at all by a small number of parameters.Because of the lack of phase model,a nonparametric detection method is proposed based on successive fractional Fourier transform and double-characters detection.The detection process goes in three steps.First,an image is constructed by the fractional Fourier transforms of successive angles in one period. Then,the threshold procedure is utilized to transform the image into a binary image.After the multiple median filtering,the binary image is refined where the isolated noise pixels are removed.Finally,two complementary features are extracted from the refined image,and a double-characters detector is proposed to decide whether the target is present or not.The simulation experiments to three polynomial phase signals with different orders and a sinusoidal phase signal show that the proposed detection method is effective and robust.

关键词： fractional Fourier transform double-characters detector nonparametric detection multiple median filtering

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

纳米团簇-牛血清白蛋白复合物界面自组装

引用

化学学报 2010年第15期68卷 1549-1552页

作者：杨小超莫志宏重庆大学生物工程学院重庆400044 重庆大学新型微纳器件与系统技术国家重点学科实验室重庆400044 重庆大学化学化工学院重庆400044

当表面电荷密度降低时,纳米粒子-蛋白质复合物可在水包油(O/W)乳液界面自组装.相对于纳米粒子,粒度较小的纳米团簇(约2nm)与蛋白质之间有更强的亲和力,因此纳米团簇-蛋白质复合物可表现出不同的自组装特性.为深入了解该特性,对纳米团簇... 详细信息

当表面电荷密度降低时,纳米粒子-蛋白质复合物可在水包油(O/W)乳液界面自组装.相对于纳米粒子,粒度较小的纳米团簇(约2nm)与蛋白质之间有更强的亲和力,因此纳米团簇-蛋白质复合物可表现出不同的自组装特性.为深入了解该特性,对纳米团簇-牛血清白蛋白(BSA)在乳液界面自组装进行研究,用Huckel方程计算自组装所需电荷密度范围,用光学和电子显微镜研究纳米团簇与BSA的交联.结果表明,纳米团簇-BSA在乳液界面的自组装驱动力同样为表面电荷密度降低,但纳米团簇与BSA的交联可造成无序自组装,要实现有序自组装,除需降低表面电荷密度外,还需控制纳米团簇与BSA的结合率。

关键词：纳米团簇蛋白质自组装界面

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：