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Global Mapping of Three-Dimensional Urban Structures Reveals Escalating Utilization in the Vertical Dimension and Pronounced Building Space Inequality 被引量:1
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作者 xiaoping liu Xinxin Wu +6 位作者 Xuecao Li Xiaocong Xu Weilin Liao Limin Jiao Zhenzhong Zeng Guangzhao Chen Xia Li 《Engineering》 2025年第4期86-99,共14页
Three-dimensional(3D)urban structures play a critical role in informing climate mitigation strategies aimed at the built environment and facilitating sustainable urban development.Regrettably,there exists a significan... Three-dimensional(3D)urban structures play a critical role in informing climate mitigation strategies aimed at the built environment and facilitating sustainable urban development.Regrettably,there exists a significant gap in detailed and consistent data on 3D building space structures with global coverage due to the challenges inherent in the data collection and model calibration processes.In this study,we constructed a global urban structure(GUS-3D)dataset,including building volume,height,and footprint information,at a 500 m spatial resolution using extensive satellite observation products and numerous reference building samples.Our analysis indicated that the total volume of buildings worldwide in2015 exceeded 1×10^(12)m^(3).Over the 1985 to 2015 period,we observed a slight increase in the magnitude of 3D building volume growth(i.e.,it increased from 166.02 km3 during the 1985–2000 period to 175.08km3 during the 2000–2015 period),while the expansion magnitudes of the two-dimensional(2D)building footprint(22.51×10^(3) vs 13.29×10^(3)km^(2))and urban extent(157×10^(3) vs 133.8×10^(3)km^(2))notably decreased.This trend highlights the significant increase in intensive vertical utilization of urban land.Furthermore,we identified significant heterogeneity in building space provision and inequality across cities worldwide.This inequality is particularly pronounced in many populous Asian cities,which has been overlooked in previous studies on economic inequality.The GUS-3D dataset shows great potential to deepen our understanding of the urban environment and creates new horizons for numerous 3D urban studies. 展开更多
关键词 THREE-DIMENSIONAL Global mapping Building volume Building height Building space inequality
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A Genome-wide association study identifies candidate genes for heat tolerance in adult cucumber plants 被引量:1
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作者 Zaizhan Wang Shaoyun Dong +9 位作者 Yanyan liu Diane M.Beckles Caixia Li Jianan Han Yi Zhang xiaoping liu Jiantao Guan Xingfang Gu Han Miao Shengping Zhang 《Horticultural Plant Journal》 2025年第2期774-787,共14页
Heat stress causes overgrowth,leaf dryness and fruit malformation,which negatively impacts cucumber quality and yield.Yet,in spite of the devastating consequences of this abiotic stress,few genes for heat tolerance in... Heat stress causes overgrowth,leaf dryness and fruit malformation,which negatively impacts cucumber quality and yield.Yet,in spite of the devastating consequences of this abiotic stress,few genes for heat tolerance in cucumber have been identified.Here,the heat injury indices of 88 cucumber accessions representing diverse ecotypes were collected in two open-field environments,with naturally occurring high temperatures over two years.Seventeen of the 88 accessions were identified as highly heat-tolerant.Using a genome-wide association study,five loci(gHII3.1,gHII3.2,gHII3.3,gHII4.1 and gHII6.1)on three chromosomes associated with heat tolerance were detected.Pairwise linkage disequilibrium correlation,sequence polymorphisms,and qRT-PCR analyses at these loci,identified five candidate genes predicted to be casual for heat stress response in cucumber.CsaV3_3G04883,CsaV3_4G029050 and CsaV3_6G005370 each had nonsynonymous SNPs,and were significantly up-regulated by heat stress in the heat-tolerant genotypes.CsaV3_3G031890 was also induced by heat stress,but in the heatsensitive genotypes,and sequence polymorphism was only found in the promoter region.Identifying these candidate genes lays a foundation for understanding cucumber thermotolerance mechanisms.Our study is one of the few to examine heat stress in adult cucumber plants and it therefore fills a critical gap in knowledge.It is also an important first-step towards accelerating the breeding of robust heat-tolerant varieties. 展开更多
关键词 Cucumis sativus L. Heat tolerance GWAS Candidate gene analysis
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Factors in Work-Related Musculoskeletal Disorders in Dentists:A Structural Equation Model
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作者 Shunhang Li Jian Li +6 位作者 Xin Xu Yushan Huang Yilin Zhang Xiaoshuang Xu Weizhen Guan xiaoping liu Jing Li 《Biomedical and Environmental Sciences》 2025年第5期639-643,共5页
Dentistry is a profession with a high prevalence of work-related musculoskeletal disorders(WMSDs),with symptoms often appearing very early in one’s career[1].WMSDs are conditions affecting the muscles,bones,and nervo... Dentistry is a profession with a high prevalence of work-related musculoskeletal disorders(WMSDs),with symptoms often appearing very early in one’s career[1].WMSDs are conditions affecting the muscles,bones,and nervous system due to occupational factors.In 2002,the International Labor Organization included musculoskeletal diseases in the International List of Occupational Diseases.China’s recently updated Classification and Catalog of Occupational Diseases has introduced two new categories of occupational illnesses,including occupational musculoskeletal disorders.WMSDs significantly impact the health and work of dentists,reducing their quality of life and causing economic losses.These disorders are multifactorial in nature,influenced by personal,psychosocial,biomechanical,and environmental factors.Dentists frequently maintain static or awkward postures during procedures,which leads to musculoskeletal strain and discomfort;additionally,long working hours contribute to psychological stress,further increasing the risk of WMSDs[2]. 展开更多
关键词 DENTISTS occupational factors classification catalog occupational diseases musculoskeletal disorders wmsds awkward postures work related musculoskeletal disorders structural equation model static postures
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Humification of organic matter and passivation of heavy metals during the hydrothermal carbonization of swine manure
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作者 Jiangbo Xiong Chunfei Zhou +7 位作者 Qingwen Zhang Huiwen Gu Yujuan Huang Pin Zhang Min Jiang Faying Lai xiaoping liu Huajun Huang 《Chinese Journal of Chemical Engineering》 2025年第12期1-12,共12页
Hydrothermal carbonization(HTC)is a promising technology for the coversion of swine manure(SM)for hydrochars(HCs).Currently,information on the humification of organic matter is limited during the HTC of SM,and its pot... Hydrothermal carbonization(HTC)is a promising technology for the coversion of swine manure(SM)for hydrochars(HCs).Currently,information on the humification of organic matter is limited during the HTC of SM,and its potential correlation with the passivation of heavy metals(HMs)remains unclear,which is crucial referece for the land application of SM-derived HCs.This study systematically investigated the humification of organic matter and the passivation of HMs during the HTC of SM and then explored their intrinsic connection.The HTC treatment can enhance the humification of organic matter,and the HCs obtained at 240℃ had the best humification effect,with the highest content of humus(83.84 mg·g^(-1)versus 41.97 mg·g^(-1)in SM)and humification rate(28.89%versus 15.73%in SM).Dissolved organic carbons(DOC)and readily oxidized organic carbons(ROC)were more easily degraded in the HTC of SM,and part was further converted into inactive organic carbon.HMs(Cu,Zn,Pb,and Cr)were enriched in HCs,but all HMs were largely passivated.The ecological risk of multi-HMs was reduced from moderate risk in SM to low risk in HCs.The percentages of HMs in exchangeable/acid-soluble forms were positively correlated with the contents of DOC and negatively correlated with the ratio of humic acids to fulvic acids(P<0.05).It was inferred that the humification of organic matter promoted the passivation of HMs in the HTC of SM.This study provided deeper insights into the humification of organic matter and it's intrinsic correlation with HMs-passivation during the HTC of SM. 展开更多
关键词 Swine manure HYDROTHERMAL Heavy metals Waste treatment Humic substances POLLUTION
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Migration/transformation characteristics of heavy metals and polycyclic aromatic hydrocarbons in the co-liquefaction treatment of pig manure and lignocellulosic biomass
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作者 Zimin Luo Xinyi Huang +3 位作者 Chunfei Zhou Min Jiang xiaoping liu Huajun Huang 《Chinese Journal of Chemical Engineering》 2025年第6期222-234,共13页
The migration/transformation characteristics of heavy metals and polycyclic aromatic hydrocarbons(PAHs) during the co-liquefaction of pig manure and rice straw/wood sawdust were explored in this study.More than 87% of... The migration/transformation characteristics of heavy metals and polycyclic aromatic hydrocarbons(PAHs) during the co-liquefaction of pig manure and rice straw/wood sawdust were explored in this study.More than 87% of the heavy metals in feedstocks were enriched in hydrochars.The decreased proportion of active heavy metals in the hydrochars suggested partial passivation of the heavy metals.The pollution degree and risk of heavy metals were significantly mitigated from high and considerable levels in pig manure to moderate and low levels in hydrochar,respectively.Compared with commercial diesel,bio-oil products still contained an undesirable amount of heavy metals.PAHs were re-synthesized during liquefaction,with a net synthesis amount of 29.65-73.98 mg·kg^(-1).Moreover,the PAHs mainly existed in bio-oils,with a content of 57.32-132.33 mg·kg^(-1) and a toxicity equivalent of3.25-8.19 mg·kg^(-1).Compared to pig manure,the hydrochars presented a lower content of PAHs(1.76-3.53 mg·kg^(-1) versus 3.73 mg·kg^(-1)) and a smaller toxicity equivalent(0.14-0.22 mg·kg^(-1) versus0.26 mg·kg^(-1)).Interestingly,introducing lignocellulose(especially for rice straw) during the liquefaction of pig manure further mitigated the pollution degree/risk of heavy metals and PAHs.Overall,hydrochar reached a safe utilization level,while bio-oil products needed further clarification. 展开更多
关键词 Waste treatment LIQUEFACTION Pollution Heavy metals PAHS Migration/transformation
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Genome-wide association study identifies candidate genes for bacterial soft rot resistance in cucumber seedlings
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作者 Yi Zhang Shaoyun Dong +8 位作者 Jiantao Guan xiaoping liu Xuewen Xie Karin Albornoz Jianan Han Zaizhan Wang Xingfang Gu Shengping Zhang Han Miao 《Horticultural Plant Journal》 2025年第3期1152-1165,共14页
Bacterial soft rot(BSR)caused by Pectobacterium carotovorum subsp.brasiliense(Pcb)is a serious bacterial disease which negatively impact yield and quality in cucumber.However,the genetic mechanism of BSR resistance in... Bacterial soft rot(BSR)caused by Pectobacterium carotovorum subsp.brasiliense(Pcb)is a serious bacterial disease which negatively impact yield and quality in cucumber.However,the genetic mechanism of BSR resistance in cucumber has not been reported.Here,we investigated the BSR resistance of 119 cucumber core germplasm worldwide at the seedling stage and identified 26 accessions highly resistant to BSR.A total of 1642740 single-nucleotide polymorphisms(SNPs)were used to conduct GWAS,and five loci associated with BSR resistance were detected on four chromosomes:gBSR2.1,gBSR2.2,gBSR3.1,gBSR4.1 and gBSR5.1.Based on haplotype analysis,sequence polymorphisms,functional annotation and qRT-PCR analysis,six candidate genes were identified within the five loci.CsaV3_2G014450,CsaV3_2G014490,CsaV3_2G016000,CsaV3_3G000850,CsaV3_4G033150,and CsaV3_5G000390 each had nonsynonymous SNPs,and were significantly up-regulated in the resistant genotypes after inoculation.And CsaV3_5G000390 in the susceptible genotype was significantly up-regulated after inoculation.The identification of these candidate genes lays a foundation for understanding the genetic mechanism of BSR resistance in cucumber.Generally,our study mined genes associated with BSR resistance in cucumber seedlings and will assist the breeding of BSR-resistant cucumber cultivars. 展开更多
关键词 Cucumis sativus Bacterial soft rot GWAS Pectobacterium carotovorum subsp.brasiliense BLUP
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Non-negligible large impact of potential forestation on livestock production in China
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作者 Changjiang Wu xiaoping liu +6 位作者 Fengsong Pei Kangyao liu Yaotong Cai Xiaocong Xu Haoming Zhuang Yiling Cai Bingjie Li 《Geography and Sustainability》 2025年第4期69-81,共13页
Forestation projects have been identified as an important component of climate mitigation strategy to reduce greenhouse gas emissions worldwide.However,most previous studies ignore the impacts of potential forestation... Forestation projects have been identified as an important component of climate mitigation strategy to reduce greenhouse gas emissions worldwide.However,most previous studies ignore the impacts of potential forestation projects on livestock production,which is crucial to the livelihoods of local people.In this study,we identified potential forestation areas in China by integrating random forest regression model and LPJ-GUESS model.The impacts of potential forestation on carbon storage and pasture-based livestock production were then analyzed.The results showed that China has a potential forestation area of 43.2 million hectares,accounting for about 19.6% of the country's forest area as reported in the 9th National Forest Inventory.If all these regions are reforested,China's forest cover will increase to 27.4%.Furthermore,1.58 Pg C of new above-and below-ground carbon would be sequestered,about an increase of 17.2% of current forest carbon storage.However,the potential forestation may result in a significant negative impact on existing pastures and the amount of livestock.It can reduce 4.7% of beef,and 0.8% of mutton products from China's livestock sector each year.These significant declines will result in a huge gap in China's livestock products supply,posing a serious threat to food security and the livelihoods of many people.Our findings highlight that potential forestation projects should further consider a reasonable pasture protection strategy to balance the potential carbon sequestration and the socio-economic benefits of livestock production. 展开更多
关键词 Forestation potential Carbon storage Livestock production Socio-economic costs
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Current Situation and Progress of Pig Model in Otology Research
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作者 xiaoping liu Maomao Ai +1 位作者 Ying Lin Feng Yu 《Journal of Biosciences and Medicines》 2024年第2期326-339,共14页
Pig models are widely used in otological research. The establishment of common pig and miniature pig animal models has opened up new fields in otological research and is also an ideal large otological animal model. Th... Pig models are widely used in otological research. The establishment of common pig and miniature pig animal models has opened up new fields in otological research and is also an ideal large otological animal model. This article introduces the applications, current status, progress, advantages, and issues of using pigs as otologic animal models. It summarizes current research on pigs in the fields of hearing disorders, otitis, vertigo, cochlea, gene editing, and tissue engineering, among other otologic and audiological areas. These models are valuable for translating basic medical science into clinical applications. Based on this, platforms have been established for studying deafness and vertigo, cochlear implantation experiments, stem cell and gene therapy, and tissue engineering. These serve as ideal experimental models for the prevention and treatment of ear diseases, pointing toward new directions. This will bolster the promotion and application of pig models in the fields of tissue engineering and gene editing in the future. 展开更多
关键词 PIG Miniature Pig Animal Model
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铅修饰纳米多孔铂催化剂对甲酸氧化的电活性(英文)
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作者 张媛媛 易清风 +3 位作者 左葛琨琨 邹涛 刘小平 周秀林 《电化学》 CAS CSCD 北大核心 2018年第3期270-278,共9页
用合适金属修饰的铂催化剂能够显著增强其对甲酸氧化的电活性.本文以水热法制备了钛负载的纳米多孔铂电极(nanoPt/Ti),然后采用循环伏安法,通过扫描不同的周数(n),用适量的铅对nanoPt/Ti电极进行修饰,得到一种新型的铅修饰的纳米多孔铂... 用合适金属修饰的铂催化剂能够显著增强其对甲酸氧化的电活性.本文以水热法制备了钛负载的纳米多孔铂电极(nanoPt/Ti),然后采用循环伏安法,通过扫描不同的周数(n),用适量的铅对nanoPt/Ti电极进行修饰,得到一种新型的铅修饰的纳米多孔铂电极(nano Pb_((n))-Pt/Ti).采用循环伏安(CV)、计时电流和计时电位法研究其对对甲酸氧化的电活性.CV结果显示nanoPt/Ti和nanoPb_((n))-Pt/Ti电极对甲酸氧化表现出较高的催化活性,并且nanoPb_((20))-Pt/Ti电极对甲酸氧化的起始电位为-0.06 V,相比nanoPt/Ti电极的起始电位(0.06 V),明显有所负移.此外,nanoPb_((20))-Pt/Ti电极的第一个氧化峰电流密度为12.7 mA·cm^(-2),远远大于nanoPt电极(4.4 mA·cm^(-2));计时电流显示在电位为0.1 V时,在0.5 mol·L^(-1)H_2SO_4+1 mol·L^(-1 )HCOOH溶液中,nanoPb_((20))-Pt/Ti电极达到稳定时的电流为8.09 mA·cm^(-2),是nanoPt电极的60倍,表明铅修饰的nanoPt/Ti对甲酸氧化的电活性急剧增加;在1.5mA、2 mA、2.2 mA和2.5 mA下的计时电位结果表明,nanoPb_((20))-Pt/Ti电极上甲酸氧化过程表现出显著的电化学振荡,且和nano Pt/Ti电极相比,振荡现象能持续更长的时间,说明nanoPb_((20))-Pt/Ti电极具有更强的表面抗毒化能力. 展开更多
关键词 甲酸氧化 纳米多孔Pt 纳米多孔Pb-Pt 电化学震荡
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绿色分离技术发展态势与展望 被引量:5
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作者 刘会洲 刘小平 +2 位作者 陈欣 张超 杨良嵘 《过程工程学报》 CAS CSCD 北大核心 2019年第S01期25-34,共10页
进入21世纪以来,绿色分离技术不断创新,新型绿色分离技术不断涌现,应用领域逐步拓展。本工作对绿色分离技术领域论文的产出规模、学术影响力、学科布局、国际合作等相关指标进行了文献计量分析,并对各项绿色分离技术进行比较分析,同时... 进入21世纪以来,绿色分离技术不断创新,新型绿色分离技术不断涌现,应用领域逐步拓展。本工作对绿色分离技术领域论文的产出规模、学术影响力、学科布局、国际合作等相关指标进行了文献计量分析,并对各项绿色分离技术进行比较分析,同时比较了中国与世界相关国家的研究实力,旨在了解中国与世界绿色分离技术的发展态势,为制定绿色分离技术发展战略和学科政策、科研工作者选择科研方向、企业投资决策等提供有益的参考。要点:(1)对绿色分离技术领域论文的产出规模、国际合作等相关指标进行了文献计量分析。(2)对各国绿色分离技术的特点进行比较分析,分析了中国与世界相关国家研究实力的差距。(3)从学科发展和产业战略需求两个方面展望了中国绿色分离技术的发展。 展开更多
关键词 绿色分离技术 论文产出规模 学术影响力 学科布局 国际合作
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不同接种污泥对厌氧氨氧化菌富集过程的影响研究
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作者 李玲玲 刘晓萍 +4 位作者 张惠姿 姜婷 赵静 李秀娟 丁瑞 《微生物前沿》 2017年第3期65-71,共7页
本研究在R1和R2两个反应器中分别接种活性高的硝化污泥和反硝化污泥以考察不同接种污泥对厌氧氨氧化菌富集过程的影响。研究结果表明,R1反应器以硝化污泥作为接种污泥,培养过程中未出现明显的菌体自溶阶段,经过约60 d成功启动厌氧氨氧... 本研究在R1和R2两个反应器中分别接种活性高的硝化污泥和反硝化污泥以考察不同接种污泥对厌氧氨氧化菌富集过程的影响。研究结果表明,R1反应器以硝化污泥作为接种污泥,培养过程中未出现明显的菌体自溶阶段,经过约60 d成功启动厌氧氨氧化反应;R2反应器以反硝化污泥作为接种污泥,出现较长的菌体自溶期,启动厌氧氨氧化反应时间比R1反应器约长20天。R1反应器和R2反应器中厌氧氨氧化反应稳定运行期间,NH+4-N去除量:NO-2-N去除量:NO-3-N生成量平均值分别为1:1.30:0.23和1:1.35:0.10。 展开更多
关键词 厌氧氨氧化 富集 硝化污泥 反硝化污泥
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保罗样激酶1保罗盒结构域:肿瘤治疗的新靶标 被引量:4
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作者 付正豪 苏美华 +1 位作者 刘晓平 陈云雨 《生物工程学报》 CAS CSCD 北大核心 2020年第11期2298-2312,I0001,共16页
保罗样激酶1(Polo-like kinase 1,Plk1)与恶性肿瘤的发生与发展密切相关,被认为是肿瘤分子靶向治疗中最具潜力的重要靶标之一。目前,针对Plk1激酶结构域(Kinase domain,KD)设计Plk1抑制剂已成为研究热点,其中部分小分子抑制剂已进入Ⅰ/... 保罗样激酶1(Polo-like kinase 1,Plk1)与恶性肿瘤的发生与发展密切相关,被认为是肿瘤分子靶向治疗中最具潜力的重要靶标之一。目前,针对Plk1激酶结构域(Kinase domain,KD)设计Plk1抑制剂已成为研究热点,其中部分小分子抑制剂已进入Ⅰ/Ⅱ期临床研究并展现出良好的抗癌前景。尽管Plk1 KD结构域抑制剂具有一定的靶标选择性,但鉴于作为ATP结合口袋的KD结构域在众多激酶结构中的高度保守性和易导致交叉耐药等问题,这使开发高选择性的Plk1 KD结构域抑制剂面临极大的挑战。保罗盒结构域(Polo-Box domain,PBD)作为Plk1特有的底物结合域,在调控Plk1的亚细胞定位中具有重要功能,被认为是未来高选择性Plk1抑制剂开发的理想靶标。文中对Plk1 PBD的分子结构、生物学功能和相关抑制剂的研究进展进行了综述和展望,以期为靶向Plk1 PBD结构域抑制剂的分子设计提供有益的借鉴和参考。 展开更多
关键词 保罗样激酶1 抑制剂 保罗盒结构域 蛋白质-蛋白质相互作用 变构调节剂 分子靶向治疗
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靶向β-catenin/TCF4相互作用小分子抑制剂酶联免疫吸附法高通量筛选模型的优化与应用 被引量:1
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作者 付正豪 闫干干 +2 位作者 朱小红 刘晓平 陈云雨 《生物工程学报》 CAS CSCD 北大核心 2021年第8期2878-2889,共12页
在经典的Wnt/β-catenin信号通路中,β-catenin/TCF4(T-cell factor 4)相互作用在非小细胞肺癌(Non-small cell lung cancer,NSCLC)的生长分化、化疗耐药、转移复发等过程中发挥着重要的促进作用,已成为新型靶向性抗NSCLC转移药物开发... 在经典的Wnt/β-catenin信号通路中,β-catenin/TCF4(T-cell factor 4)相互作用在非小细胞肺癌(Non-small cell lung cancer,NSCLC)的生长分化、化疗耐药、转移复发等过程中发挥着重要的促进作用,已成为新型靶向性抗NSCLC转移药物开发的理想靶标之一。为了高效地发现抑制β-catenin/TCF4相互作用的苗头化合物,本研究在应用酶联免疫吸附实验(Enzyme-linkedimmunosorbentassay,ELISA)原理的基础上,通过优化GST-TCF4βBD包被浓度和β-catenin反应浓度,建立ELISA高通量筛选模型并成功应用于苗头化合物的筛选。ELISA筛选模型优化实验结果表明,选用2μg/mL GST-TCF4βBD和0.5μg/mLβ-catenin建立ELISA高通量筛选模型,其Z′因子值为0.83,并成功筛选到具有良好抑制活性的白花丹素(Plumbagin)。肿瘤细胞增殖实验结果表明,白花丹素对A549、H1299、MCF7和SW480细胞具有明显的细胞毒性。TOPFlash实验结果证实,白花丹素对转染的HEK293细胞内β-catenin介导的转录活性具有显著的抑制作用,β-catenin/TCF4相互作用可能是白花丹素抗癌活性的潜在分子靶标之一。文中以β-catenin/TCF4相互作用为靶标,通过系统的实验优化方案,成功地建立了适用于药物高通量筛选的ELISA筛选模型,为高效筛选靶向β-catenin/TCF4相互作用的小分子抑制剂奠定了实验基础。 展开更多
关键词 Wnt抑制剂 β-catenin/TCF4相互作用 酶联免疫吸附实验 高通量筛选 血根碱 白花丹素
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浅谈制药工程专业有机化学实验教学的心得和体会——以三苯甲醇的制备和重结晶实验为例 被引量:3
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作者 叶文静 潘洁 +2 位作者 姜军 刘晓平 王凯 《大学化学》 CAS 2020年第7期109-113,共5页
有机化学实验是制药工程专业的一门必修课,旨在训练学生有机合成基本实验技能。本文以三苯甲醇的制备和重结晶实验为例,讲述了笔者在多年教学中获得的一点感悟和经验:1)将实验步骤分解成片断讲解可以使学生更好地理解和记忆实验过程和... 有机化学实验是制药工程专业的一门必修课,旨在训练学生有机合成基本实验技能。本文以三苯甲醇的制备和重结晶实验为例,讲述了笔者在多年教学中获得的一点感悟和经验:1)将实验步骤分解成片断讲解可以使学生更好地理解和记忆实验过程和操作目的;2)重要的基本操作应反复练习,即“学习、复习、提高”,通过三次重复练习来实现巩固和熟练掌握该操作的目的。 展开更多
关键词 有机化学实验 三苯甲醇的制备 重结晶 实验步骤的分解 重复练习
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养分添加和降水变化对荒漠草原地上和地下生物量稳定性的影响 被引量:1
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作者 尹星元 安慧 +5 位作者 邢彬彬 苏诗玉 文志林 郭建超 刘小平 王波 《生物多样性》 CAS CSCD 北大核心 2024年第7期14-24,共11页
为明确荒漠草原生态系统功能和稳定性对水分和养分资源可利用性改变的响应,阐明荒漠草原生物量稳定性的影响机制及途径,本研究在宁夏荒漠草原开展了为期5年的养分添加和降水变化野外控制试验(2018-2022年),试验包括9个处理:对照(Cont)、... 为明确荒漠草原生态系统功能和稳定性对水分和养分资源可利用性改变的响应,阐明荒漠草原生物量稳定性的影响机制及途径,本研究在宁夏荒漠草原开展了为期5年的养分添加和降水变化野外控制试验(2018-2022年),试验包括9个处理:对照(Cont)、N添加(N)、NPK添加(NPK)、减少50%降水(Cont–50%)、增加50%降水(Cont+50%)、N添加+减少50%降水(N–50%)、N添加+增加50%降水(N+50%)、NPK添加+减少50%降水(NPK–50%)和NPK添加+增加50%降水(NPK+50%)。通过测定地上、地下生物量及物种多样性,分析了物种异步性、物种多样性、生物量稳定性及生物量稳定性的影响因素。结果表明:(1)养分添加和降水变化显著影响荒漠草原植物群落生物量,NPK+50%处理增加了地上生物量(156.28%)、地下生物量(51.95%)及总生物量(75.67%),而Cont–50%处理降低了地上生物量(45.59%)、地下生物量(25.09%)及总生物量(31.41%);(2)除NPK+50%处理外,其他处理的地上生物量、地下生物量和总生物量稳定性均显著低于对照处理。NPK+50%处理降低了地上生物量稳定性(31.90%),但增加了地下和总生物量稳定性(33.48%和12.38%);(3)养分添加和降水变化显著影响物种多样性(物种丰富度和Shannon-Wiener多样性指数)和物种异步性,其交互作用对物种异步性有显著影响;(4)降水变化通过降低物种异步性进而降低地上生物量稳定性和总生物量稳定性。地上生物量稳定性对总生物量稳定性无显著的直接效应,而地下生物量稳定性对总生物量稳定性具有显著正效应。综上所述,养分添加和降水变化降低荒漠草原生物量稳定性,物种异步性(互补效应)是荒漠草原生物量稳定性的主要影响机制。在荒漠草原地区地下生物量稳定性对总生物量稳定性的贡献大于地上生物量稳定性,因此,在探究植物群落稳定性对养分添加和降水变化的响应模式及其机制时,不能仅局限于植物地上部分的研究,也要充分考虑植物地下部分的变化和响应。 展开更多
关键词 荒漠草原 养分添加 降水变化 地下生物量稳定性 总生物量稳定性
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Neural Network-Based Adaptive Motion Control for a Mobile Robot with Unknown Longitudinal Slipping 被引量:10
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作者 Gang Wang xiaoping liu +1 位作者 Yunlong Zhao Song Han 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第4期26-34,共9页
When the mobile robot performs certain motion tasks in complex environment, wheel slipping inevitably occurs due to the wet or icy road and other reasons, thus directly influences the motion control accuracy. To addre... When the mobile robot performs certain motion tasks in complex environment, wheel slipping inevitably occurs due to the wet or icy road and other reasons, thus directly influences the motion control accuracy. To address unknown wheel longitudinal slipping problem for mobile robot, a RBF neural network approach based on whole model approximation is presented. The real-time data acquisition of inertial measure unit(IMU), encoders and other sensors is employed to get the mobile robot’s position and orientation in the movement, which is applied to compensate the unknown bounds of the longitudinal slipping using the adaptive technique. Both the simulation and experimental results prove that the control scheme possesses good practical performance and realize the motion control with unknown longitudinal slipping. 展开更多
关键词 Mobile robot Longitudinal slipping RBF neural network ADAPTIVE control
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Genome-wide analysis of expansins and their role in fruit spine development in cucumber(Cucumis sativus L.) 被引量:10
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作者 xiaoping liu Shaoyun Dong +5 位作者 Han Miao Kailiang Bo Caixia Li Yingying Yang Xingfang Gu Shengping Zhang 《Horticultural Plant Journal》 SCIE CAS CSCD 2022年第6期757-768,共12页
Cucumber is one of the most widely consumed vegetables worldwide,and the fruit spine is an important fruit quality trait.Expansins play critical roles in fruit development;however,the regulation of expansins in cucumb... Cucumber is one of the most widely consumed vegetables worldwide,and the fruit spine is an important fruit quality trait.Expansins play critical roles in fruit development;however,the regulation of expansins in cucumber fruit spine development has not been reported.In this study,33 expansin genes were identified in the cucumber genome V3;additionally,expansin genes in Citrullus lanatus,Cucumis melo,Cucurbita maxima,Lagenaria siceraria,and Benincasa hispida were also identified.Phylogenetic analysis of expansin proteins in Cucurbitaceae and Arabidopsis showed that they evolved separately in each plant species.Phylogenetic analysis showed that C.maxima was derived earlier than the other five Cucurbitaceae species.The expression of CsEXPA2,CsEXPA14,and CsEXLA3 varied in cucumber lines with different fruit spine densities.A yeast two-hybrid assay showed that a putative auxin transporter encoded by numerous spine gene(ns)interacts with CsEXLA2,which may be involved in the development of the numerous spines in cucumber.These results provide novel insights into the expansins related to plant development and fruit spine development in cucumber. 展开更多
关键词 CUCUMBER EXPANSINS Phylogenetic analysis COLLINEARITY Gene expression Fruit spine
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Dynamic response to climate change in the radial growth of Picea schrenkiana in western Tien Shan,China 被引量:9
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作者 Liang Jiao Shengjie Wang +1 位作者 Ke Chen xiaoping liu 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第1期147-157,共11页
Forests are important ecosystems for economic and social development.However,the response of tree radial growth to climate has produced‘divergent problems'at high latitudes under global warming.In this study,the ... Forests are important ecosystems for economic and social development.However,the response of tree radial growth to climate has produced‘divergent problems'at high latitudes under global warming.In this study,the response stability and trend of Picea schrenkiana radial growth to variability in climate factors were analyzed in the mid-latitudes of the western Tien Shan Mountains.Radial growth of P.schrenkiana was mainly limited by minimum and mean temperatures.The divergent responses of radial growth occurred in response to the minimum and mean temperatures at the beginning of the growing season(April–May)of the current year,but responses to drought occurred in July–September of the previous year.And the mean and minimum temperatures in June–September of the current year were both stable.Radial growth first increased and then decreased according to the basal area increment,with a gradual increase in temperature.Therefore,forest ecosystems in mountainous arid areas will be increasingly affected by future climate warming. 展开更多
关键词 DENDROECOLOGY Divergent response Climate change Forest degradation Western Tien Shan mountains
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人源抗ICAM-1单链抗体的制备及其生物学活性鉴定 被引量:1
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作者 陈云雨 孙红 +4 位作者 刘刚 胡华波 张国利 刘晓平 岳玉环 《生物工程学报》 CAS CSCD 北大核心 2018年第12期2016-2024,共9页
利用噬菌体展示技术筛选特异性人源抗ICAM-1单链抗体(Anti-human ICAM-1 scFv)并进行生物学活性鉴定。应用TomlinsonI+J噬菌体抗体库,以P1抗原肽为包被抗原,经过4轮"吸附-洗脱-扩增"进行亲和富集筛选。以PCR反应、ELISA抗原... 利用噬菌体展示技术筛选特异性人源抗ICAM-1单链抗体(Anti-human ICAM-1 scFv)并进行生物学活性鉴定。应用TomlinsonI+J噬菌体抗体库,以P1抗原肽为包被抗原,经过4轮"吸附-洗脱-扩增"进行亲和富集筛选。以PCR反应、ELISA抗原交叉反应和Dot blotting实验进行阳性克隆的鉴定。scFv经原核表达和分离纯化后,以Western blotting实验、竞争ELISA实验和细胞黏附抑制实验对其生物学活性进行初步鉴定。Tomlinson I+J噬菌体抗体库经4轮亲和富集筛选,利用ELISA方法成功筛出4株阳性克隆。通过PCR鉴定反应、ELISA抗原交叉反应和Dot blotting实验,最终获得了1株既能与P1抗原肽特异结合又能与人ICAM-1抗原特异结合的阳性克隆J-A1。对scFv进行原核表达和亲和层析后获得了高纯度的目的蛋白。竞争ELISA实验和细胞黏附抑制实验证实纯化的scFv具有良好的亲和活性和抗细胞黏附活性。文中成功利用噬菌体展示技术筛选到特异性人源抗ICAM-1 scFv,为进一步探索该抗体在炎症相关性疾病治疗中的应用奠定了基础。 展开更多
关键词 噬菌体展示技术 细胞间黏附分子 ICAM-1 单链抗体 人源化抗体
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Barriers to the Acceptance of Tuberculosis Preventive Treatment:A Multicenter Cross-sectional Study in China 被引量:3
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作者 Jingjuan Ren &Fei Huang +16 位作者 Haifeng Chen Huimin Zhang Jianwei Sun Ahui Zhao Zuhui Xu Liqin liu Huizhong Wu Lanjun Fang Chengguo Wu Qingya Wang Wenqian Zhang Xinhua Sun xiaoping liu Jizheng Yuan Bohan Chen Ni Wang Yanlin Zhao 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第11期1303-1309,共7页
Objective We aimed to understand the willingness and barriers to the acceptance of tuberculosis(TB)preventive treatment(TPT)among people with latent TB infection(LTBI)in China.Methods A multicenter cross-sectional stu... Objective We aimed to understand the willingness and barriers to the acceptance of tuberculosis(TB)preventive treatment(TPT)among people with latent TB infection(LTBI)in China.Methods A multicenter cross-sectional study was conducted from May 18,2023 to December 31,2023 across 10 counties in China.According to a national technical guide,we included healthcare workers,students,teachers,and others occupations aged 15-65 years as our research participants.Results Overall,17.0%(183/1,077)of participants accepted TPT.There were statistically significant differences in the acceptance rate of TPT among different sexes,ages,educational levels,and occupations(P<0.05).The main barriers to TPT acceptance were misconceptions that it had uncertain effects on prevention(57.8%,517/894),and concerns about side effects(32.7%,292/894).Conclusion An enhanced and comprehensive understanding of LTBI and TPT among people with LTBI is vital to further expand TPT in China.Moreover,targeted policies need to be developed to address barriers faced by different groups of people. 展开更多
关键词 Latent tuberculosis infection Tuberculosis preventive treatment ACCEPTANCE Healthcare workers STUDENTS TEACHERS
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