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Desertification in the Mu Us Sandy Land in China:Response to climate change and human activity from 2000 to 2020 被引量:3
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作者 Xin Wang Jinling Song +2 位作者 zhiqiang xiao Jing Wang Fangze Hu 《Geography and Sustainability》 2022年第2期177-189,共13页
China is a country largely affected by desertification.The main purpose of this article is to analyze interannual and seasonal changes in fractional vegetation cover(FVC)in the Mu Us Sandy Land(MUSL).It uses fused rem... China is a country largely affected by desertification.The main purpose of this article is to analyze interannual and seasonal changes in fractional vegetation cover(FVC)in the Mu Us Sandy Land(MUSL).It uses fused remote sensing data to quantitatively analyze the response of FVC to climate change and human activities.The results showed that desertification in the MUSL had improved over the past 20 years.Grade V desertification decreased from more than 60%in 2000 to about 15%in 2020.In some years,degradation appeared to be affected by climate factors and human activity,especially in the northwestern portion of the study area.The FVC in summer was slightly higher than that in autumn and far higher than recorded in spring and winter.Spatially,the northwestern and central parts of the study area were unstable,with high coefficients of variation.FVC gradually increased from northwest to southeast,and areas with the fastest increase in FVC were concentrated along the eastern and southern edges of the study area.The correlations between FVC and precipitation and dryness were slightly pos-itive,but the correlation between FVC and temperature showed regional differences.The increase of population density is not a key factor limiting the growth of vegetation;the policy of“grazing prohibition,grazing rest,and rotational grazing”has allowed the restoration of vegetation;and afforestation is an effective way to promote the increase in FVC. 展开更多
关键词 Mu Us Sandy Land(MUSL) Mann-Kendall test STARFM model
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Transcriptional pausing induced by ionizing radiation enables the acquisition of radioresistance in nasopharyngeal carcinoma
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作者 Honglu Liu Huanyi Fu +9 位作者 Chunhong Yu Na Zhang Canhua Huang Lu Lv Chunhong Hu Fang Chen zhiqiang xiao Zhuohua Zhang Huasong Lu Kai Yuan 《Journal of Molecular Cell Biology》 SCIE CAS CSCD 2023年第7期15-30,共16页
Lesions on the DNA template can impact transcription via distinct regulatory pathways.Ionizing radiation(IR)as the mainstay modality for many malignancies elicits most of the cytotoxicity by inducing a variety of DNA ... Lesions on the DNA template can impact transcription via distinct regulatory pathways.Ionizing radiation(IR)as the mainstay modality for many malignancies elicits most of the cytotoxicity by inducing a variety of DNA damages in the genome.How the IR treatment alters the transcription cycle and whether it contributes to the development of radioresistance remain poorly understood.Here,we report an increase in the paused RNA polymerase II(RNAPII),as indicated by the phosphorylation at serine 5 residue of its C-terminal domain,in recurrent nasopharyngeal carcinoma(NPC)patient samples after IR treatment and cultured NPC cells developing IR resistance.Reducing the pool of paused RNAPII by either inhibiting TFIIH-associated CDK7 or stimulating the positive transcription elongation factor b,a CDK9-CycT1 heterodimer,attenuates IR resistance of NPC cells.Interestingly,the poly(ADP-ribosyl)ation of CycT1,which disrupts its phase separation,is elevated in the IR-resistant cells.Mutation of the major poly(ADP-ribosyl)ation sites of CycT1 decreases RNAPII pausing and restores IR sensitivity.Genome-wide chromatin immunoprecipitation followed by sequencing analyses reveal that several genes involved in radiation response and cell cycle control are subject to the regulation imposed by the paused RNAPII.Particularly,we identify the NIMA-related kinase NEK7 under such regulation as a new radioresistancefactor,whose downregulation results in the increased chromosome instability,enabling the development of IR resistance.Overall,our results highlight a novel link between the alteration in the transcription cycle and the acquisition of IR resistance,opening up new opportunities to increase the efficacy of radiotherapy and thwart radioresistance in NpC. 展开更多
关键词 RNA polymerase II transcriptional pausing RADIORESISTANCE CDK7 NEK7 nasopharyngeal carcinoma
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湖南八大公山25 ha常绿落叶阔叶混交林动态监测样地群落组成与空间结构 被引量:14
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作者 秦运芝 张佳鑫 +11 位作者 刘检明 刘梦婷 万丹 吴浩 周阳 孟红杰 肖之强 黄汉东 徐耀粘 卢志军 乔秀娟 江明喜 《生物多样性》 CAS CSCD 北大核心 2018年第9期1016-1022,共7页
湖南八大公山国家级自然保护区位于武陵山系北缘,区内分布有大面积的常绿落叶阔叶混交林,物种多样性丰富,群落结构复杂。中国科学院武汉植物园按CTFS (Center for Tropical Forest Sciences)建设规范于2010–2011年在保护区内建设了一个... 湖南八大公山国家级自然保护区位于武陵山系北缘,区内分布有大面积的常绿落叶阔叶混交林,物种多样性丰富,群落结构复杂。中国科学院武汉植物园按CTFS (Center for Tropical Forest Sciences)建设规范于2010–2011年在保护区内建设了一个25 ha的动态监测样地,为亚热带山地森林群落多样性长期动态监测提供了理想的平台。本文初步分析了八大公山25ha样地的群落组成与空间结构。结果表明:群落内共有木本植物存活个体186,575株,隶属于53科114属232种;个体数超过1,000株的有38个物种(贡献87%的个体数),个体数最多的物种为黄丹木姜子(Litsea elongata);样地内稀有种(≤25株)种数占样地总物种数的44%,而个体数仅为样地总个体数的0.4%。样地内个体平均胸径为5.41cm,其中68.4%的个体DBH≤5cm,DBH≥20cm的个体数(7,474株)仅约占总个体数的4%;个体胸径直方图呈倒"J"形,表明样地处于良好更新与正常生长状态。样地的种–面积关系图显示物种数随样地面积的增加而同步增加,其增长速度由迅速增长逐渐趋于稳定,取样面积10 ha时可以涵盖90%以上的物种; 1 ha小样地个体数平均为7,261.8±974.8 (SD),物种数平均为128.2±8.2 (SD), Shannon-Wiener指数平均为3.56±0.11 (SD),Pielou均匀度指数变异最小,平均为1.69±0.06 (SD);个体数与各多样性指数均无显著相关,表明在该样地中物种多样性的取样效应不明显,物种数量增加的原因可能来自于其他因素的控制。 展开更多
关键词 群落结构 武陵山系 Α多样性 种-多度分布 种-面积关系
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A long-term Global LAnd Surface Satellite(GLASS)data-set for environmental studies 被引量:27
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作者 Shunlin Liang Xiang Zhao +13 位作者 Suhong Liu Wenping Yuan xiao Cheng zhiqiang xiao xiaotong Zhang Qiang Liu Jie Cheng Hairong Tang Yonghua Qu Yancheng Bo Ying Qu Huazhong Ren Kai Yu John Townshend 《International Journal of Digital Earth》 SCIE EI 2013年第S01期5-33,共29页
Recently,five Global LAnd Surface Satellite(GLASS)products have been released:leaf area index(LAI),shortwave broadband albedo,longwave broadband emissivity,incident short radiation,and photosynthetically active radiat... Recently,five Global LAnd Surface Satellite(GLASS)products have been released:leaf area index(LAI),shortwave broadband albedo,longwave broadband emissivity,incident short radiation,and photosynthetically active radiation(PAR).The first three products cover the years 19822012(LAI)and 19812010(albedo and emissivity)at 15 km and 8-day resolutions,and the last two radiation products span the period 20082010 at 5 km and 3-h resolutions.These products have been evaluated and validated,and the preliminary results indicate that they are of higher quality and accuracy than the existing products.In particular,the first three products have much longer time series,and are therefore highly suitable for various environmental studies.This paper outlines the algorithms,product characteristics,preliminary validation results,potential applications and some examples of initial analysis of these products. 展开更多
关键词 earth observation global environmental change remote sensing
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Normalization cancer immunotherapy: blocking Siglec-15! 被引量:6
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作者 Guangchao Cao zhiqiang xiao Zhinan Yin 《Signal Transduction and Targeted Therapy》 SCIE CSCD 2019年第1期576-577,共2页
In a recent paper published in Nature medicine,Wang,J.,et al.identified Siglec-15 as a new candidate responsible for adaptive immune resistance and a potential target for normalization cancer immunotherapy.1 Cancer ce... In a recent paper published in Nature medicine,Wang,J.,et al.identified Siglec-15 as a new candidate responsible for adaptive immune resistance and a potential target for normalization cancer immunotherapy.1 Cancer cells can develop various mechanisms to evade tumor-specific and non-specific attacks in the TME of solid tumors.2 Thus,systemic activation of immune systems or even increasing tumor-specific T cells in the peripheral does not necessarily lead to tumor regression.In fact,almost all the known strategies adopted by cancer for immune escape are also used for maintaining systemic homeostasis. 展开更多
关键词 IMMUNOTHERAPY CANCER al.
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Enhanced cobalamin biosynthesis in Ensifer adhaerens by regulation of key genes with gradient promoters
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作者 Sha Xu zhiqiang xiao +3 位作者 Shiqin Yu Weizhu Zeng Yongming Zhu Jingwen Zhou 《Synthetic and Systems Biotechnology》 SCIE 2022年第3期941-948,共8页
Cobalamin is an essential human vitamin widely used in the pharmaceutical,food,and feed additive industries and currently produced by bacteria or archaea.Ensifer adhaerens HY-1 is an industrial strain that also produc... Cobalamin is an essential human vitamin widely used in the pharmaceutical,food,and feed additive industries and currently produced by bacteria or archaea.Ensifer adhaerens HY-1 is an industrial strain that also produces cobalamin.However production outputs are poor and the specific synthesis pathways require characterization.In this study,the whole genome sequence of E.adhaerens HY-1 was generated and annotated,and genes associated with cobalamin biosynthesis were identified.Then,three genes,CobSV,CobQ,and CobW were identified as the most efficient ones for enhancing cobalamin synthesis.By transcriptome sequencing of E.adhaerens HY-1 cells at different growth stages,65 endogenous promoters with different gradient strengths were identified.After combined expression of different strength promoters and key genes,a high cobalamin-producing recombinant strain,‘hmm’(genotype:PmetH-CobSV-PibpA-CobQ-Pmdh-CobW),was generated.Cobalamin production was 143.8 mg/L in shaking flasks,which was 41.0%higher than the original strain.Cobalamin production was further enhanced to 171.2 mg/L using fed-batch fermentation.Importantly,our data and novel approach provide important references for the analysis of cobalamin synthesis and other metabolites in complex metabolic pathways. 展开更多
关键词 Ensifer adhaerens COBALAMIN Genome sequence Transcriptome sequence PROMOTER OVEREXPRESSION COMBINATIONS
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Evaluation of county-level poverty alleviation progress by deep learning and satellite observations
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作者 Yanxiao Jiang Liqiang Zhang +6 位作者 Yang Li Jintai Lin Jingwen Li Guoqing Zhou Suhong Liu Jing Cao zhiqiang xiao 《Big Earth Data》 EI 2021年第4期576-592,共17页
Poverty alleviation is one of the greatest challenges faced by low-income and middle-income countries.China,which had the largest rural poverty-stricken population,has made tremendous efforts in alleviating poverty es... Poverty alleviation is one of the greatest challenges faced by low-income and middle-income countries.China,which had the largest rural poverty-stricken population,has made tremendous efforts in alleviating poverty especially since the implementation of the targeted poverty alleviation(TPA)policy in 2014,and by 2020,all national poverty-stricken counties(NPCs)have been out of poverty.This study combines deep learning with multiple satellite datasets to estimate county-level economic develop-ment from 2008 to 2019 and assess the effect of the TPA policy for 592 national poverty-stricken counties(NPCs)at country,provincial and county levels.Per capita gross domestic product(GDP)is used to measure the affluence level.From 2014 through 2019,the 592 NPCs experience an average growth rate of per capita GDP at 7.6%±0.4%,higher than the average growth rate of 310 adjacent non-NPC counties(7.3%±0.4%)and of the whole country(6.3%).We also reveal 42 counties with weak growth recently and that the average affluence level of the NPCs in 2019 is still much lower than the national or provincial averages.The inexpensive,timely and accurate method proposed here can be applied to other low-income and middle-income countries for affluence assessment. 展开更多
关键词 Poverty alleviation remote sensing imagery deep learning county level
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Lkb1 orchestrates γδ T-cell metabolic and functional fitness to control IL-17-mediated autoimmune hepatitis
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作者 zhiqiang xiao Shanshan Wang +8 位作者 Liang Luo Wenkai Lv Peiran Feng Yadong Sun Quanli Yang Jun He Guangchao Cao Zhinan Yin Meixiang Yang 《Cellular & Molecular Immunology》 SCIE CAS 2024年第6期546-560,共15页
γδT cells play a crucial role in immune surveillance and serve as a bridge between innate and adaptive immunity.However,the metabolic requirements and regulation ofγδT-cell development and function remain poorly u... γδT cells play a crucial role in immune surveillance and serve as a bridge between innate and adaptive immunity.However,the metabolic requirements and regulation ofγδT-cell development and function remain poorly understood.In this study,we investigated the role of liver kinase B1(Lkb1),a serine/threonine kinase that links cellular metabolism with cell growth and proliferation,inγδT-cell biology.Our findings demonstrate that Lkb1 is not only involved in regulatingγδT lineage commitment but also plays a critical role inγδT-cell effector function.Specifically,T-cell-specific deletion of Lkb1 resulted in impaired thymocyte development and distinct alterations inγδT-cell subsets in both the thymus and peripheral lymphoid tissues.Notably,loss of Lkb1 inhibited the commitment of Vγ1 and Vγ4γδT cells,promoted the maturation of IL-17-producing Vγ6γδT cells,and led to the occurrence of fatal autoimmune hepatitis(AIH).Notably,clearance ofγδT cells or blockade of IL-17 significantly attenuated AIH.Mechanistically,Lkb1 deficiency disrupted metabolic homeostasis and AMPK activity,accompanied by increased mTORC1 activation,thereby causing overactivation ofγδT cells and enhanced apoptosis.Interestingly,activation of AMPK or suppression of mTORC1 signaling effectively inhibited IL-17 levels and attenuated AIH in Lkb1-deficient mice.Our findings highlight the pivotal role of Lkb1 in maintaining the homeostasis ofγδT cells and preventing IL-17-mediated autoimmune diseases,providing new insights into the metabolic programs governing the subset determination and functional differentiation of thymicγδT cells. 展开更多
关键词 Lkb1 γδT cell Autoimmune hepatitis IL-17 Metabolic quiescence
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