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A Pore-Forming Strategy Toward Porous Carbon-Based Substrates for High Performance Flexible Lithium Metal Full Batteries 被引量:1
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作者 yanfei li Shuyang Ye +7 位作者 Jian lin Yihan Song Xinglong Wu Jingping Zhang Changlu Shao Zhongmin Su Haizhu Sun Dwight S.Seferos 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第3期117-125,共9页
Self-standing carbon-based substrates with satisfied structural stability and property adjustability have promising applications in flexible lithium(Li)metal batteries(FLMBs).Current strategies for modifying carbon ma... Self-standing carbon-based substrates with satisfied structural stability and property adjustability have promising applications in flexible lithium(Li)metal batteries(FLMBs).Current strategies for modifying carbon materials are normally carried out on powder carbon,and very few of them are suitable for self-standing carbon substrates.Herein,a pore-forming strategy based on the redox chemistry of metallic oxide nanodots is developed to prepare two porous carbon substrates for anode and cathode.Starting with cotton cloth,the resulting hollow carbon fibers substrate with nanopores effectively prevents from Li dendrites formation and large volume change in lithium metal anode(LMA).Simulations indicate that the porous structure leads to homogeneous ion flux,Li-ion concentration,and electric field during Li deposition.Li symmetrical cell based on this substrate remains stable for 8300 h with an ultralow voltage hysteresis of 9 mV.Via a similar route,porous carbon cloth substrate is obtained for subsequently seeding V_(2)O_(5)nanowires to prepare the cathode.The assembled FLMBs pouch cell delivers a capacity of 8.2 mAh with a high capacity retention of~100%even under dramatic deformation.The demonstrated strategy has far-reaching potential in preparing free-standing porous carbon-based materials for flexible energy storage devices. 展开更多
关键词 dual-function carbon substrates flexible lithium metal full batteries lithium metal anode porous structure V_(2)O_(5)cathode
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铜氢催化不饱和烃与醛、酮的亲核加成反应
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作者 赵悦 李雁飞 熊涛 《大学化学》 CAS 2024年第4期280-285,共6页
金属有机试剂(如:有机锂试剂、格氏试剂、有机铜试剂及有机铝试剂)对醛、酮的加成反应是有机化学中的重要反应,也是最经典的构建C―C键的方法之一。然而上述金属有机试剂存在官能团兼容性较差、对水和空气敏感及不易存储等缺陷,不可避... 金属有机试剂(如:有机锂试剂、格氏试剂、有机铜试剂及有机铝试剂)对醛、酮的加成反应是有机化学中的重要反应,也是最经典的构建C―C键的方法之一。然而上述金属有机试剂存在官能团兼容性较差、对水和空气敏感及不易存储等缺陷,不可避免地限制了其广泛应用。近年来,利用稳定、易得的不饱和烃为原料替代金属有机试剂参与各种化学转化受到了人们高度关注。本文主要介绍在铜氢催化条件下,通过把不饱和烃现场转化为催化量有机铜中间体替代传统化学计量金属有机试剂的策略,实现其对醛、酮的加成反应,从而避免了传统方法的缺点。对于上述反应的介绍,能够丰富和拓展基础教学过程中亲核加成知识点的内容,开阔学生的视野与思维,有利于学生了解学科前沿领域的发展现状,激发学生的兴趣。 展开更多
关键词 铜氢催化 不饱和烃 金属有机试剂 亲核加成
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GmAP1d regulates flowering time under long-day photoperiods in soybean
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作者 Shiyu Guo yanfei li +9 位作者 Hongmei Qiu Guoyu Hu Chaosen Zhao Ruizhen Wang Hao Zhang Yu Tian Xiaoyu li Bin liu Ying-hui li li-juan Qiu 《The Crop Journal》 SCIE CSCD 2024年第3期845-855,共11页
Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We id... Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We identified three strong signals at the qFT02-2 locus(Chr02:12037319–12238569),which were associated with flowering time in three environments:Gongzhuling,Mengcheng,and Nanchang.By analyzing linkage disequilibrium,gene expression patterns,gene annotation,and the diversity of variants,we identified an AP1 homolog as the candidate gene for the qFT02-2 locus,which we named GmAP1d.Only one nonsynonymous polymorphism existed among 1490 soybean accessions at position Chr02:12087053.Accessions carrying the Chr02:12087053-T allele flowered significantly earlier than those carrying the Chr02:12087053-A allele.Thus,we developed a cleaved amplified polymorphic sequence(CAPS)marker for the SNP at Chr02:12087053,which is suitable for marker-assisted breeding of flowering time.Knockout of GmAP1d in the‘Williams 82’background by gene editing promoted flowering under long-day conditions,confirming that GmAP1d is the causal gene for qFT02-2.An analysis of the region surrounding GmAP1d revealed that GmAP1d was artificially selected during the genetic improvement of soybean.Through stepwise selection,the proportion of modern cultivars carrying the Chr02:12087053-T allele has increased,and this allele has become nearly fixed(95%)in northern China.These findings provide a theoretical basis for better understanding the molecular regulatory mechanism of flowering time in soybean and a target gene that can be used for breeding modern soybean cultivars adapted to different latitudes. 展开更多
关键词 SOYBEAN Flowering time GWAS GmAP1d Long-day conditions
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Flavonoid extracts from chrysanthemum with appropriate anthocyanins turn blue when exposed to iron ions
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作者 yanfei li Jiaying Wang +8 位作者 Chenfei Lu Zhongman Wang Chengyan Deng Kang Gao Jingjing li Zhijun Fang Hao liu Yan Hong Silan Dai 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第3期837-852,共16页
Although some species that accumulate only cyanidin(Cy)in nature can produce blue flowers through iron ions,there has been no evidence of blue chrysanthemums being generated in this manner.This study revealed that fla... Although some species that accumulate only cyanidin(Cy)in nature can produce blue flowers through iron ions,there has been no evidence of blue chrysanthemums being generated in this manner.This study revealed that flavonoid extracts from the ray florets of the chrysanthemum cultivar‘Wandai Fengguang’turned blue when exposed to Fe^(3+).Samples that could turn blue were labeled as CB(Cy-determined blue flowers),while samples that did not turn blue were labeled as CN(Cy-determined non-blue flowers).After a series of experiments,a stable screening system was established using flavonoid extracts containing NaAc buffer at pH 5.5 and a total anthocyanin concentration(TAC)of 30 μmol·L^(-1),and the addition of Fe^(3+)from 0 to 0.25 μmol·L^(-1)allowed for the selection of five CB samples from 39 chrysanthemum cultivars.All five CB samples exhibited flower color phenotypes that belonged to Cluster-I with redness(a*)values ranging from 29.03 to 45.99,yellowness(b*)values from-11.31 to 3.77,and brightness(L*)values from 29.07 to 45.99.Additionally,the ratio of TAC to total luteolin concentration(TLC)was found to be a critical factor for distinguishing between CB and CN samples.To realize the desired blue hue in the flavonoid extracts with the participation of Fe^(3+),a TAC to TLC ratio of 2.25 and above is required.Moreover,the protoplasts and ray florets of CB samples that turned blue with the involvement of Fe^(2+)showed great potential for cultivating blue chrysanthemums through ferric-anthocyanin chelate.Overall,this study reveals that blue flowers can be cultivated through the increase in the iron ion concentration,combined with the accumulation of Cy. 展开更多
关键词 Chrysanthemum×morifolium CYANIDIN Copigment Ferric-anthocyanin chelate Blue flower
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Research on the Coordinated Development of Inclusive Finance and Financing for Small and Medium-sized Enterprises
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作者 yanfei li Xue liang 《Proceedings of Business and Economic Studies》 2024年第4期214-219,共6页
As an important force in promoting economic and social development,small and medium-sized enterprises play a crucial role in enhancing China’s economic strength,creating employment opportunities,and promoting industr... As an important force in promoting economic and social development,small and medium-sized enterprises play a crucial role in enhancing China’s economic strength,creating employment opportunities,and promoting industrial structural transformation.However,due to their inherent weaknesses,small and medium-sized enterprises often face difficulties in financing within the traditional financial service system.This makes it difficult for small and medium-sized enterprises to inject vitality into the development of the market economy by expanding their financing scale.Since 2013,China has vigorously developed inclusive finance and extended the services of traditional financial institutions to small and medium-sized enterprises,providing policy guidance,resource support,and technical support to alleviate the financing difficulties of small and medium-sized enterprises.Based on this,this article focuses on the current financing problems faced by small and medium-sized enterprises and specifically elaborates on how to lower the financing threshold for small and medium-sized enterprises and broaden their financing channels through inclusive finance,in order to promote the development of inclusive finance and a virtuous cycle of financing for small and medium-sized enterprises. 展开更多
关键词 Inclusive finance Financing for small and medium-sized enterprises Financial institution
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Profiling of seed fatty acid composition in 1025 Chinese soybean accessions from diverse ecoregions 被引量:6
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作者 Ahmed M.Abdelghany Shengrui Zhang +7 位作者 Muhammad Azam Abdulwahab S.Shaibu Yue Feng yanfei li Yu Tian Huilong Hong Bin li Junming Sun 《The Crop Journal》 SCIE CAS CSCD 2020年第4期635-644,共10页
The stability of soybean(Glycine max L.Merrill)oil is determined mainly by its fatty acid(FA)composition.We evaluated the FA composition of 1025 Chinese soybean accessions collected from diverse ecoregions and grown i... The stability of soybean(Glycine max L.Merrill)oil is determined mainly by its fatty acid(FA)composition.We evaluated the FA composition of 1025 Chinese soybean accessions collected from diverse ecoregions and grown in multiple locations and years.We observed highly significant differences(P<0.001)between accessions in palmitic acid(PA),stearic acid(SA),oleic acid(OA),linoleic acid(LA),and linolenic acid(LNA)contents.Growth year affected(P<0.001)the abundance of all FAs except PA.The mean PA,SA,OA,LA,and LNA contents were 12.2%,3.8%,21.5%,54.2%,and 8.3%,respectively.The geographical origin of the accession influenced seed FA composition,indicating that accessions originating in each ecoregion tend to have distinct FA composition.We observed significant positive correlations among the three locations and between the two years,suggesting the high heritability and stability of individual accessions across contrasting environments.We also observed a relatively high negative correlation between the contents of OA and both LA and LNA(r=-0.90 and-0.59,respectively,each significant at P<0.001),providing a potential entry point for developing strains producing oil with higher OA and lower LA and LNA levels.These would be appropriate for specialized use in the food industry.Our results will be useful in breeding soybean with improved quality to meet human nutritional and industrial needs. 展开更多
关键词 SOYBEAN BREEDING GLYCINE
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A Novel Training Sequence Applied to DCS-Based Channel Estimation 被引量:2
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作者 Weizhang Xu Xinle Yu +2 位作者 yanfei li Lu Si Zhanxin Yang 《China Communications》 SCIE CSCD 2018年第11期70-78,共9页
Studies have indicated that the distributed compressed sensing based(DCSbased) channel estimation can decrease the length of the reference signals effectively. In block transmission, a unique word(UW) can be used as a... Studies have indicated that the distributed compressed sensing based(DCSbased) channel estimation can decrease the length of the reference signals effectively. In block transmission, a unique word(UW) can be used as a cyclic prefix and reference signal. However, the DCS-based channel estimation requires diversity sequences instead of UW. In this paper, we proposed a novel method that employs a training sequence(TS) whose duration time is slightly longer than the maximum delay spread time. Based on proposed TS, the DCS approach perform perfectly in multipath channel estimation. Meanwhile, a cyclic prefix construct could be formed, which reduces the complexity of the frequency domain equalization(FDE) directly. Simulation results demonstrate that, by using the method of simultaneous orthogonal matching pursuit(SOMP), the required channel overhead has been reduced thanks to the proposed TS. 展开更多
关键词 jointly sparse channel estimation distributed compressed sensing (DCS) simul-taneous orthogonal matching pursuit (SOMP) training sequence (TS) unique word (UW) frequency domain equalization (FDE)
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Econometric analysis of the impacts of climate change on the livestock production in Qinghai Province
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作者 yanfei li Xinsheng Wang +1 位作者 Zhihui li Fang Yin 《Chinese Journal of Population,Resources and Environment》 2013年第4期299-307,共9页
This study aims to investigate the effect of the impact mechanism of climate change on the livestock production at small watershed level and county level with the Multi-level Model(MLM)in Qinghai Province.The result i... This study aims to investigate the effect of the impact mechanism of climate change on the livestock production at small watershed level and county level with the Multi-level Model(MLM)in Qinghai Province.The result indicated that the gross livestock output value was greatly influenced by the climatic factors of the small watershed level.Higher temperature promoted also by the increase of precipitation,relative humidity and sunshine duration was found to be beneficial to the development of livestock production,except in some areas where temperature rise restrained the development of local livestock production to some degree when exceeding a certain level;besides,the impact of the socioeconomic factors on the livestock output value is obvious at the county level.The gross economic output measured with GDP has some inhibitory effects on the reinvestment of livestock production,while population growth promotes development of livestock production to some degree.The results not only provide scientific basis for the management of livestock production in Qinghai Province,but also provide reference for formulating the policies and adaptation measures targeted at climate change to promote the sustainable development of livestock production in other regions. 展开更多
关键词 CLIMATE CHANGE LIVESTOCK production MULTI-LEVEL Model QINGHAI PROVINCE
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Clinical Pathological Analysis in 104 Ductal Breast Cancer Cases
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作者 Yueling Jin Xiuying Huang +2 位作者 yanfei li Xuemei li Zhensheng Dai 《Journal of Biosciences and Medicines》 2017年第12期37-43,共7页
Ductal breast cancer is a clinically heterogeneous disease;we investigate the correlation between tumor size, comedo necrosis, number of cell mitoses and axillary lymph node metastasis in ductal breast cancer. In this... Ductal breast cancer is a clinically heterogeneous disease;we investigate the correlation between tumor size, comedo necrosis, number of cell mitoses and axillary lymph node metastasis in ductal breast cancer. In this study, 104 ductal breast cancer specimens were collected and divided into 3 groups: T1 group (tumor size ≤ 2 cm), T2 group (2 5.0 cm). Among those specimens, 95 cases were diagnosed with invasive ducted carcinoma, and 9 cases were ductal carcinoma in-situ (DCIS). Results show that T3 group has a higher rate of axillary lymph node metastasis than T2 group and T1 group;T2 group has a higher rate of lymph node metastasis than T1 group. The patients with the number of cell mitoses (≥10) were also has a higher rate of axillary lymph node metastasis (P = 0.0139) than the patients with the number of cell mitoses (<10). No significance was found between comedo necrosis lesions and axillary lymph node metastasis, though the frequency of comedo necrosis lesions in patients with axillary lymph node metastasis was higher than those in non-metastatic patients. It is concluded that the tumor size and the number of cell mitoses were risk factors for axillary lymph node involvement in ductal breast cancer. 展开更多
关键词 PATHOLOGICAL Analysis DUCTAL BREAST Cancer LYMPH NODE METASTASIS
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Optimization of Crosswalk Width Based on Bi-Directional Pedestrian Crossing Time at Signalized Intersections
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作者 Ningbo Cao Yongheng Chen +3 位作者 Zhaowei Qu liying Zhao yanfei li Qiujie Yang 《Journal of Beijing Institute of Technology》 EI CAS 2018年第2期285-292,共8页
The effects of the interactions between bi-directional pedestrians on the crossing time and the crosswalk width are studied. Firstly,the crossing process of bi-directional pedestrians is analyzed.The total crosswalk t... The effects of the interactions between bi-directional pedestrians on the crossing time and the crosswalk width are studied. Firstly,the crossing process of bi-directional pedestrians is analyzed.The total crosswalk time is divided into a discharge time and a crossing time. The interactions between bi-directional pedestrians are quantified with the drag force theory. Then,a model is developed to study the crossing time based on the kinetic energy theory and momentum theory. Subsequently,the related parameters of the proposed model are calibrated with observed information. The relationships among crosswalk width,signal time,pedestrian volume and level of service are simulated with the proposed model. The results are verified and compared with other models. The proposed model has an absolute value of relative error of 9. 38%,which is smaller than that of the Alhajyaseen model( 15. 26%) and Highway Capacity Manual( HCM) model( 12. 42%). Finally,suggested crosswalk widths at different conditions are successfully estimated with the proposed crossing time model. 展开更多
关键词 signalized crosswalks bi-directional pedestrian drag force theory crossing time cross-walk width
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Research for radiation-hardened high-voltage SOI LDMOS 被引量:4
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作者 yanfei li Shaoli Zhu +2 位作者 Jianwei Wu Genshen Hong Zheng Xu 《Journal of Semiconductors》 EI CAS CSCD 2019年第5期41-45,共5页
Based on the silicon-on-insulator(SOI) technology and radiation-hardened silicon gate(RSG) process, a radiation-hardened high-voltage lateral double-diffused MOSFET(LDMOS) device is presented in this paper. With the g... Based on the silicon-on-insulator(SOI) technology and radiation-hardened silicon gate(RSG) process, a radiation-hardened high-voltage lateral double-diffused MOSFET(LDMOS) device is presented in this paper. With the gate supply voltage of 30 V, the LDMOS device has a gate oxide thickness of 120 nm, and the RSG process is effective in reducing the total ionizing dose(TID) radiation-induced threshold voltage shift. The p-type ion implantation process and gate-enclosed layout topology are used to prevent radiation-induced leakage current through a parasitic path under the bird's beak and at the deep trench corner,and the device is compatible with high-voltage SOI CMOS process. In the proposed LDMOS, the total ionizing dose radiation degradation for the ON bias is more sensitive than the OFF bias. The experiment results show that the SOI LDMOS has a negative threshold voltage shift of 1.12 V, breakdown voltage of 135 V, and off-state leakage current of 0.92 pA/μm at an accumulated dose level of 100 krad(Si). 展开更多
关键词 radiation-hardened RGS total ion dose threshold voltage shift
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Tobacco Rattle Virus-induced Phytoene Desaturase (PDS) Silencing in Centaurea cyanus 被引量:2
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作者 Chengyan Deng Fan Zhang +3 位作者 Jiaying Wang yanfei li He Huang Silan Dai 《Horticultural Plant Journal》 SCIE CSCD 2021年第2期159-166,共8页
Virus-induced gene silencing(VIGS)is a genetic tool used to assess gene function.Tobacco rattle virus(TRV)is a VIGS vector commonly used to induce endogenous gene silencing in plants.However,there is no VIGS system es... Virus-induced gene silencing(VIGS)is a genetic tool used to assess gene function.Tobacco rattle virus(TRV)is a VIGS vector commonly used to induce endogenous gene silencing in plants.However,there is no VIGS system established for Centaurea spp.We evaluated the effectiveness of a TRV-based VIGS system using phytoene desaturase(PDS)as a reporter gene in Centaurea cyanus.Three methods including pressure-,vacuum-and apical meristem-infiltrationwere tested to infect C.cyanus seedlings.Photobleached leaveswere only obtained using apicalmeristem-infiltration after a 14 d treatment.The CcPDS transcripts in photobleached leaves were significantly reduced compared with that in green leaves treated with empty TRV.Four C.cyanus cultivars were tested to detect their VIGS responses,and‘Dwarf Tom Pouce Blue’was the most sensitive.The agro-infiltration condition was optimized by screening for the optimal seedling stage as well as the optimum Agrobacterium density for efficient silencing.Seedlings with four true leaves and infiltration with an Agrobacterium density of OD_(600)0.5 were optimal conditions to obtain more photobleached leaves and more intense photobleached phenotype.The results demonstrated the feasibility of TRV-based VIGS for functional analysis of genes in C.cyanus. 展开更多
关键词 Centaurea cyanus VIGS tobacco rattle virus PDS SEEDLING photobleached
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Proton radiography of magnetic fields generated with an open-ended coil driven by high power laser pulses 被引量:2
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作者 Guoqian liao Yutong li +17 位作者 Baojun Zhu yanfei li Fang li Mengchao li Xuan Wang Zhe Zhang Shukai He Weiwu Wang Feng Lu Faqiang Zhang Lei Yang Kainan Zhou Na Xie Wei Hong Yuqiu Gu Zongqing Zhao Baohan Zhang Jie Zhang 《Matter and Radiation at Extremes》 SCIE EI CAS 2016年第4期187-191,共5页
Recently generation of strong magnetic(B)fields has been demonstrated in capacitor coils heated by high power laser pulses[S.Fujioka et al.,Sci.Rep.3,1170(2013)].This paper will present a direct measurement of B field... Recently generation of strong magnetic(B)fields has been demonstrated in capacitor coils heated by high power laser pulses[S.Fujioka et al.,Sci.Rep.3,1170(2013)].This paper will present a direct measurement of B field generated with an open-ended coil target driven by a nanosecond laser pulse using ultrafast proton radiography.The radiographs are analyzed with particle-tracing simulations.The B field at the coil center is inferred to be ~50 T at an irradiance of ~5×10^(14) W·cm^(-2).The B field generation is attributed to the background cold electron flow pointing to the laser focal spot,where a target potential is induced due to the escape of energetic electrons. 展开更多
关键词 Strong magnetic field Laser-driven coil targets Proton radiography
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RPA3 is transcriptionally activated by YY1 and its depletion enhances radiosensitivity of triple-negative and HER2-positive breast cancer
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作者 yanfei li LULU DAI +2 位作者 KE CAI YINGKUI SONG XIQING liU 《BIOCELL》 SCIE 2021年第3期685-694,共10页
RPA3(Replication Protein A3)(14 kD)is a part of the canonical heterotrimeric replication protein A complex(RPA/RP-A).This study aimed to explore the functional role of RPA3 and the mechanisms of its dysregulation in b... RPA3(Replication Protein A3)(14 kD)is a part of the canonical heterotrimeric replication protein A complex(RPA/RP-A).This study aimed to explore the functional role of RPA3 and the mechanisms of its dysregulation in breast cancer.Data from the Cancer Genome Atlas(TCGA)-breast cancer patients and GSE75688 were utilized for gene expression and survival analysis.Breast cancer cell lines MDA-MB-231 and SK-BR-3 were used for in-vitro cell studies.Clonogenic assay and immunofluorescent staining ofγ-H2AX were performed to examine radiation-induced cytotoxicity.Systemic correlation analysis was performed to identify potential transcription factors(TFs)regulating RPA3 expression.ChIP-qPCR and dual-luciferase assay were conducted to verify the transcriptional activating effect of YY1 on RPA3 expression.Bioinformatic analysis showed that RPA3 expression was upregulated in breast cancer.Its upregulation was associated with poor survival of basal-like and HER2+cases.RPA3 inhibition by siRNA reduced colony formation and increasedγ-H2AX foci formation after irradiation in MDA-MB-231 and SK-BR-3 cells.RPA3 expression was transcriptionally activated by YY1 via promoter binding in the two cell lines.Both RPA3 and YY1 expression were positively correlated with their gene-level copy numbers.RPA3 might serve as a potential target for radio-sensitization in basal-like and HER2+breast cancer. 展开更多
关键词 RPA3 YY1 Breast cancer RADIOTHERAPY
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A new species of Phamartes Bresseel & Constant(Phasmatodea: Diapheromeridae: Necrosciinae) from Vietnam
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作者 yanfei li Wenjun BU 《Entomotaxonomia》 CSCD 2019年第3期188-191,共4页
This article describes one new species,Phamartes elongatus sp.nov.from Cát Tiên National Park,Vietnam.Photographs of the adult and genitalia are provided and a key to the two know species is provided based o... This article describes one new species,Phamartes elongatus sp.nov.from Cát Tiên National Park,Vietnam.Photographs of the adult and genitalia are provided and a key to the two know species is provided based on the female. 展开更多
关键词 stick insects TAXONOMY KEY
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Survey and Analysis of Community Care Service in Cities and Towns from the Perspective of Internet
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作者 Jiaxu HUANG Jiaqi li +2 位作者 yanfei li Ying WANG Shuli SONG 《Asian Agricultural Research》 2020年第9期33-34,共2页
With the aging of the social population,community care has become another important care model between home care and institutional care.In order to fully understand the social cognition and demand of"Internet+com... With the aging of the social population,community care has become another important care model between home care and institutional care.In order to fully understand the social cognition and demand of"Internet+community care",the project team conducted a questionnaire survey in accordance with the research objectives.The survey concluded that the public are still dependent on the traditional care,and do not know much about"Internet+community care",but are willing to try."Internet+community care"can not only enrich and innovate the care model,but also effectively solve the problems of limited pension resources and mismatch between supply and demand.It is conducive to promoting the realization of high-quality and efficient services for the aged. 展开更多
关键词 Internet+ Cities and towns Community care
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Unconditional Superconvergence Analysis of Energy Conserving Finite Element Methods for the Nonlinear Coupled Klein-Gordon Equations
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作者 Ming Cui yanfei li Changhui Yao 《Advances in Applied Mathematics and Mechanics》 SCIE 2023年第3期602-622,共21页
In this paper,we consider the energy conserving numerical scheme for coupled nonlinear Klein-Gordon equations.We propose energy conserving finite element method and get the unconditional superconvergence resultO(h^(2)... In this paper,we consider the energy conserving numerical scheme for coupled nonlinear Klein-Gordon equations.We propose energy conserving finite element method and get the unconditional superconvergence resultO(h^(2)+Dt^(2))by using the error splitting technique and postprocessing interpolation.Numerical experiments are carried out to support our theoretical results. 展开更多
关键词 Energy conserving the nonlinear coupled Klein-Gordon equations unconditional superconvergence result postprocessing interpolation finite element method
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Copper-catalyzed conjugate addition of allene-derived nucleophiles to alkenyl-substituted carboxamides
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作者 Bin Fu Yue Zhao +5 位作者 Xiuping Yuan yanfei li Jianjun Yin Simin Wang Tao Xiong Qian Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第3期239-242,共4页
Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry.Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging.We here... Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry.Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging.We herein report a copper-catalyzed conjugate addition of allenes toβ-substituted alkenyl amides,one of the most challenging Michael acceptors.The present method utilizes readily available allenes as the latent carbon-based nucleophiles and simple,commonβ-substituted alkenyl amides as starting materials,unlike previous methods that usually preinstall an activating group to improve the reactivity of amide or uses highly reactive stoichiometric quantities of organometallics.Hence,this approach shows good functional group compatibility and can be implemented under mild reaction conditions with excellent level of chemo-and regioselectivities. 展开更多
关键词 CuH catalysis ALLENES Unsaturated amide Conjugate addition Regioselectivity
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Epidemiological Characterization of Dengue Fever—Yunnan Province,China,2010-2021
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作者 Xiaoxiang Zhu Songwang Wang +3 位作者 yanfei li Yu Cao Xuemei Su Xiaotao Zhao 《China CDC weekly》 SCIE CSCD 2024年第20期457-462,I0002-I0007,共12页
Objective:The goal of this study is to analyze the epidemiological patterns of dengue fever across different districts and counties in Yunnan Province from 2010 to 2021.Methods:In this study,we employed joinpoint regr... Objective:The goal of this study is to analyze the epidemiological patterns of dengue fever across different districts and counties in Yunnan Province from 2010 to 2021.Methods:In this study,we employed joinpoint regression analysis,spatial autocorrelation analysis,and space-time scan analysis to illustrate the spatiotemporal propagation and demographic influence of dengue fever,using both graphical and tabular presentations to clearly demonstrate the findings.Results:Yunnan Province reported 14,098 cases of dengue fever during the period from 2010 to 2021.Of these,11,513 cases were caused by local transmission,2,566 were imported internationally,and 19 were inter-provincial imports.Seasonal trends emerged,revealing a surge in incidences during the summer and autumn months.The sex ratio of male to female cases was 1:0.88,with a significant majority of 82.00%of cases involving individuals belonging to the age group of 15-60.Commercial service workers constituted the most impacted occupational group,forming 20.96%of total cases.A spatio-temporal scan identified significant clustering of dengue fever cases across space and time,with the most pronounced cluster observed in southern Yunnan,primarily between 2015 and 2019.Conclusions:Dengue fever in Yunnan Province manifests as biennial outbreaks,underscoring the necessity for increased surveillance,particularly in counties bordering other regions. 展开更多
关键词 counties DISTRICT REVEALING
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Recent Progress in Automotive Gasoline Direct Injection Engine Technology 被引量:9
20
作者 Shijin Shuai Xiao Ma +2 位作者 yanfei li Yunliang Qi Hongming Xu 《Automotive Innovation》 EI 2018年第2期95-113,共19页
Gasoline direct injection(GDI)engines are currently the dominant powertrains for passenger cars.With the implementation of increasingly stringent fuel consumption and emission regulationsworldwide,GDI engines are faci... Gasoline direct injection(GDI)engines are currently the dominant powertrains for passenger cars.With the implementation of increasingly stringent fuel consumption and emission regulationsworldwide,GDI engines are facing challenges owing to high particulate matter emissions and a tendency to knock,leading to a change in the research and design(R&D)issues compared with those in the twentieth century.This paper reviews the progress in research regarding GDI engine technologies over the past 20 years,focusing on combustion system configurations,and also highlights common issues in GDI R&D,including pre-ignition and deto-knock,soot formation and PM emissions,injector deposits and gasoline compression ignition(GCI).First,an overview of recent developments in the field as driven by regulations is provided,following which progress in injection and combustion systems is examined.Third,the review addresses the occurrence and mechanism of deto-knock and considers means of suppressing this phenomenon.The fourth section discusses soot formation mechanisms and particulate matter emission characteristics of GDI engines and describes the application of gasoline particulate filter(GPF)after-treatment.The subsequent section summarizes studies regarding injector deposit formation,as well as pioneering research into GCI combustion modes.Finally,a summary and future prospects for GDI engine technologies are provided. 展开更多
关键词 Gasoline directioninjection Combustionsystem Pre-ignition PARTICULATEMATTER Injector deposit Gasoline compression ignition
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