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Effects of conductive agent type on lithium extraction from salt lake brine with LiFePO_(4)electrodes
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作者 zhen zhang Pan Luo +7 位作者 Yan zhang Yuhan Wang Li Liao Bo Yu Mingshan Wang Junchen Chen Bingshu Guo Xing Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第4期678-687,共10页
Electrochemical lithium extraction from salt lakes is an effective strategy for obtaining lithium at a low cost.Nevertheless,the elevated Mg:Li ratio and the presence of numerous coexisting ions in salt lake brines gi... Electrochemical lithium extraction from salt lakes is an effective strategy for obtaining lithium at a low cost.Nevertheless,the elevated Mg:Li ratio and the presence of numerous coexisting ions in salt lake brines give rise to challenges,such as prolonged lithium extraction periods,diminished lithium extraction efficiency,and considerable environmental pollution.In this work,Li FePO4(LFP)served as the electrode material for electrochemical lithium extraction.The conductive network in the LFP electrode was optimized by adjusting the type of conductive agent.This approach resulted in high lithium extraction efficiency and extended cycle life.When the single conductive agent of acetylene black(AB)or multiwalled carbon nanotubes(MWCNTs)was replaced with the mixed conductive agent of AB/MWCNTs,the average diffusion coefficient of Li+in the electrode increased from 2.35×10^(-9)or 1.77×10^(-9)to 4.21×10^(-9)cm^(2)·s^(-1).At the current density of 20 mA·g^(-1),the average lithium extraction capacity per gram of LFP electrode increased from 30.36 mg with the single conductive agent(AB)to 35.62 mg with the mixed conductive agent(AB/MWCNTs).When the mixed conductive agent was used,the capacity retention of the electrode after 30 cycles reached 82.9%,which was considerably higher than the capacity retention of 65.8%obtained when the single AB was utilized.Meanwhile,the electrode with mixed conductive agent of AB/MWCNTs provided good cycling performance.When the conductive agent content decreased or the loading capacity increased,the electrode containing the mixed conductive agent continued to show excellent electrochemical performance.Furthermore,a self-designed,highly efficient,continuous lithium extraction device was constructed.The electrode utilizing the AB/MWCNT mixed conductive agent maintained excellent adsorption capacity and cycling performance in this device.This work provides a new perspective for the electrochemical extraction of lithium using LFP electrodes. 展开更多
关键词 salt lake brine lithium extraction electrochemical lithium extraction conductive agent extraction efficiency adsorption capacity
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O_(3)氧化法选择性浮选分离辉钼矿和黄铜矿
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作者 张红涛 宋翔宇 +3 位作者 黄业豪 张振 王文 徐来福 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第1期298-308,共11页
研究O_(3)氧化对黄铜矿和辉钼矿浮选回收率的影响。单矿物浮选试验结果表明,在O_(3)浓度约为90 g/m^(3)、气体流量为4 L/min的条件下,黄铜矿和辉钼矿氧化2 min后,黄铜矿的浮选回收率降至16%,而辉钼矿的浮选回收率变化不大。人工混矿浮... 研究O_(3)氧化对黄铜矿和辉钼矿浮选回收率的影响。单矿物浮选试验结果表明,在O_(3)浓度约为90 g/m^(3)、气体流量为4 L/min的条件下,黄铜矿和辉钼矿氧化2 min后,黄铜矿的浮选回收率降至16%,而辉钼矿的浮选回收率变化不大。人工混矿浮选试验结果表明,在选择性浮选黄铜矿和辉钼矿中,O_(3)氧化预处理可以代替Na2S试剂作为铜抑制剂。接触角测量结果表明,O_(3)氧化处理选择性地使黄铜矿表面具有亲水性。Zeta电位和X射线光电子能谱分析结果表明,氧化处理后黄铜矿表面产生不溶于水的亲水性氧化物和氢氧化物,使得黄铜矿更加亲水;此外,辉钼矿的表面虽略有氧化,但其表面仍保持疏水性。 展开更多
关键词 黄铜矿 辉钼矿 O_(3)氧化 选择性浮选 亲水性
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For Mega-Constellations: Edge Computing and Safety Management Based on Blockchain Technology
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作者 zhen zhang Bing Guo Chengjie Li 《China Communications》 SCIE CSCD 2024年第2期59-73,共15页
In mega-constellation Communication Systems, efficient routing algorithms and data transmission technologies are employed to ensure fast and reliable data transfer. However, the limited computational resources of sate... In mega-constellation Communication Systems, efficient routing algorithms and data transmission technologies are employed to ensure fast and reliable data transfer. However, the limited computational resources of satellites necessitate the use of edge computing to enhance secure communication.While edge computing reduces the burden on cloud computing, it introduces security and reliability challenges in open satellite communication channels. To address these challenges, we propose a blockchain architecture specifically designed for edge computing in mega-constellation communication systems. This architecture narrows down the consensus scope of the blockchain to meet the requirements of edge computing while ensuring comprehensive log storage across the network. Additionally, we introduce a reputation management mechanism for nodes within the blockchain, evaluating their trustworthiness, workload, and efficiency. Nodes with higher reputation scores are selected to participate in tasks and are appropriately incentivized. Simulation results demonstrate that our approach achieves a task result reliability of 95% while improving computational speed. 展开更多
关键词 blockchain consensus mechanism edge computing mega-constellation reputation management
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For LEO Satellite Networks: Intelligent Interference Sensing and Signal Reconstruction Based on Blind Separation Technology
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作者 Chengjie Li Lidong Zhu zhen zhang 《China Communications》 SCIE CSCD 2024年第2期85-95,共11页
In LEO satellite communication networks,the number of satellites has increased sharply, the relative velocity of satellites is very fast, then electronic signal aliasing occurs from time to time. Those aliasing signal... In LEO satellite communication networks,the number of satellites has increased sharply, the relative velocity of satellites is very fast, then electronic signal aliasing occurs from time to time. Those aliasing signals make the receiving ability of the signal receiver worse, the signal processing ability weaker,and the anti-interference ability of the communication system lower. Aiming at the above problems, to save communication resources and improve communication efficiency, and considering the irregularity of interference signals, the underdetermined blind separation technology can effectively deal with the problem of interference sensing and signal reconstruction in this scenario. In order to improve the stability of source signal separation and the security of information transmission, a greedy optimization algorithm can be executed. At the same time, to improve network information transmission efficiency and prevent algorithms from getting trapped in local optima, delete low-energy points during each iteration process. Ultimately, simulation experiments validate that the algorithm presented in this paper enhances both the transmission efficiency of the network transmission system and the security of the communication system, achieving the process of interference sensing and signal reconstruction in the LEO satellite communication system. 展开更多
关键词 blind source separation greedy optimization algorithm interference sensing LEO satellite communication networks signal reconstruction
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A dynamic regulation of nitrogen on floret primordia development in wheat
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作者 zhen zhang Yujing Li +6 位作者 Yuxun Wu Xiaoyu zheng Xiaolei Guo Wan Sun zhencai Sun Zhimin Wang Yinghua zhang 《The Crop Journal》 SCIE CSCD 2024年第1期271-280,共10页
Nitrogen(N)fertilization is critical for spike and floret development,which affects the number of fertile florets per spike(NFFs).However,the physiological regulation of the floret development process by N fertilizati... Nitrogen(N)fertilization is critical for spike and floret development,which affects the number of fertile florets per spike(NFFs).However,the physiological regulation of the floret development process by N fertilization is largely unknown.A high temporal-resolution investigation of floret primordia number and morphology,dry matter,and N availability was conducted under three N fertilization levels:0(N0),120(N1)and 240(N2)kg ha^(−1).Interestingly,fertile florets at anthesis stage were determined by those floret primordia with meiotic ability at booting stage:meiotic ability was a threshold that predicted whether a floret primordium became fertile or abortive florets.Because the developmental rate of the 4th floret primordium in the central spikelet was accelerated and then they acquired meiotic ability,the NFFs increased gradually as N application increased,but the increase range decreased under N2.There were no differences in spike N concentration among treatments,but leaf N concentration was increased in the N1 and N2 treatments.Correspondingly,dry matter accumulation and N content of the leaf and spike in the N1 and N2 treatments was increased as compared to N0.Clearly,optimal N fertilization increased leaf N availability and transport of assimilates to spikes,and allowed more floret primordia to acquire meiotic ability and become fertile florets,finally increasing NFFs.There was no difference in leaf N concentration between N1 and N2 treatment,whereas soil N concentration at 0–60 cm soil layers was higher in N2 than in N1 treatment,implying that there was still some N fertilization that remained unused.Therefore,improving the leaf’s ability to further use N fertilizer is vital for greater NFFs. 展开更多
关键词 Fertile florets Floret primordia Grain number Meiotic ability Morphological development
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Spatial transcriptomics reveals that metabolic characteristics define the tumor immunosuppression microenvironment via iCAF transformation in oral squamous cell carcinoma
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作者 Zheqi Liu zhen zhang +7 位作者 Yu zhang Wenkai Zhou Xu zhang Canbang Peng Tong Ji Xin Zou Zhiyuan zhang zhenhu Ren 《International Journal of Oral Science》 SCIE CAS CSCD 2024年第1期110-121,共12页
Tumor progression is closely related to tumor tissue metabolism and reshaping of the microenvironment. Oral squamous cell carcinoma (OSCC), a representative hypoxic tumor, has a heterogeneous internal metabolic enviro... Tumor progression is closely related to tumor tissue metabolism and reshaping of the microenvironment. Oral squamous cell carcinoma (OSCC), a representative hypoxic tumor, has a heterogeneous internal metabolic environment. To clarify the relationship between different metabolic regions and the tumor immune microenvironment (TME) in OSCC, Single cell (SC) and spatial transcriptomics (ST) sequencing of OSCC tissues were performed. The proportion of TME in the ST data was obtained through SPOTlight deconvolution using SC and GSE103322 data. The metabolic activity of each spot was calculated using scMetabolism,and k-means clustering was used to classify all spots into hyper-, normal-, or hypometabolic regions. CD4T cell infiltration and TGF-βexpression is higher in the hypermetabolic regions than in the others. Through CellPhoneDB and NicheNet cell-cell communication analysis, it was found that in the hypermetabolic region, fibroblasts can utilize the lactate produced by glycolysis of epithelial cells to transform into inflammatory cancer-associated fibroblasts (iCAFs), and the increased expression of HIF1A in iCAFs promotes the transcriptional expression of CXCL12. The secretion of CXCL12 recruits regulatory T cells (Tregs), leading to Treg infiltration and increased TGF-β secretion in the microenvironment and promotes the formation of a tumor immunosuppressive microenvironment. This study delineates the coordinate work axis of epithelial cells-iCAFs-Tregs in OSCC using SC, ST and TCGA bulk data, and highlights potential targets for therapy. 展开更多
关键词 CXCL12 MICROENVIRONMENT SQUAMOUS
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Emergence of highly pathogenic avian influenza A(H5N8)clade 2.3.4.4b viruses in grebes in Inner Mongolia and Ningxia,China,in 2021
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作者 Qiuzi Xu Xinru Lü +17 位作者 Yi Li Hua Luo zhen zhang Xiang Li Rongxiu Qin Qing An Fengyi Qu zhenliang Zhao Chengbo zhang Weidong Wang Yuecheng Li Yajun Wang Xiangwei Zeng Zhijun Hou Jingqiang Ren Yulong Wang Yanbing Li Hongliang Chai 《Journal of Integrative Agriculture》 SCIE CSCD 2024年第1期348-353,共6页
Highly pathogenic avian influenza(HPAI)subtype H5Nx viruses have spread globally and are a major concern for poultry,wild birds,mammals,and even humans(de Vries et al.2015;Zeng et al.2022).The hemagglutinin(HA)genes o... Highly pathogenic avian influenza(HPAI)subtype H5Nx viruses have spread globally and are a major concern for poultry,wild birds,mammals,and even humans(de Vries et al.2015;Zeng et al.2022).The hemagglutinin(HA)genes of H5 subtype viruses have evolved into multiple clades and some of these clades have been further divided into subclades(Cui et al.2022).Clade 2.3.4.4H5N8 HPAI viruses(HPAIVs)have caused several waves of disease outbreaks in wild birds and domestic poultry(Wang et al.2022). 展开更多
关键词 POULTRY Ningxia INFLUENZA
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The Precursor of GRB211211A:A Tide-induced Giant Quake?
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作者 Enping Zhou Yong Gao +9 位作者 Yurui Zhou Xiaoyu Lai Lijing Shao Weiyang Wang Shaolin Xiong Renxin Xu Shuxu Yi Garvin Yim Han Yue zhen zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第2期206-215,共10页
The equilibrium configuration of a solid strange star in the final inspiral phase with another compact object is generally discussed,and the starquake-related issue is revisited,for a special purpose to understand the... The equilibrium configuration of a solid strange star in the final inspiral phase with another compact object is generally discussed,and the starquake-related issue is revisited,for a special purpose to understand the precursor emission of binary compact star merger events(e.g.,that of GRB211211A).As the binary system inspirals inward due to gravitational wave radiation,the ellipticity of the solid strangeon star increases due to the growing tidal field of its compact companion.Elastic energy is hence accumulated during the inspiral stage which might trigger a starquake before the merger when the energy exceeds a critical value.The energy released during such starquakes is calculated and compared to the precursor observation of GRB211211 A.The result shows that the energy might be insufficient for binary strangeon-star case unless the entire solid strangeon star shatters,and hence favors a black hole-strangeon star scenario for GRB211211A.The timescale of the precursor as well as the frequency of the observed quasi-periodic-oscillation have also been discussed in the starquake model. 展开更多
关键词 STARS neutron-(stars:)gamma-ray burst general-black hole physics
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A Search for Radio Pulsars in Supernova Remnants Using FAST with One Pulsar Discovered
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作者 张振 闫文明 +8 位作者 袁建平 王娜 白俊涛 温志刚 李保达 解进涛 赵德 王榆斌 翟楠楠 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第2期133-136,共4页
We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST telescope.The observations were made using the 19-beam receiver in“snapshot”mode.The integration time for each pointi... We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST telescope.The observations were made using the 19-beam receiver in“snapshot”mode.The integration time for each pointing was 10 min.We discovered a new pulsar,PSR J1845–0306,which has a spin period of 983.6 ms and a dispersion measure of 444.6±2.0 cm^(−3)·pc,in observations of SNR G29.6+0.1.To judge the association between the pulsar and the SNR,further verification is needed.We also re-detected some known pulsars in the data from SNRs G29.6+0.1 and G29.7–0.3.No pulsars were detected in the observations of the other three SNRs. 展开更多
关键词 OBSERVATIONS Pulsar pulsar
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肟的立体选择性合成概述
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作者 张圳 杨凯 宋秋玲 《大学化学》 CAS 2024年第1期105-110,共6页
立体化学纯的肟被广泛应用于有机合成、药物、食品添加剂等领域。传统方法合成肟的立体选择性取决于底物取代基的空间位阻,其立体选择性合成一直是有机合成领域的难点与挑战。本文简要介绍了立体选择性合成肟的新方法和技术的研究进展... 立体化学纯的肟被广泛应用于有机合成、药物、食品添加剂等领域。传统方法合成肟的立体选择性取决于底物取代基的空间位阻,其立体选择性合成一直是有机合成领域的难点与挑战。本文简要介绍了立体选择性合成肟的新方法和技术的研究进展。本文的内容来源于基础有机化学,将此内容融入到教学中可以拓展学生的视野,也有助于激发学生发现和解决难题的兴趣。 展开更多
关键词 立体选择性 贝克曼重排 交叉偶联 光异构化
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Peroxisome proliferator-activated receptors gama ameliorates liver fibrosis in non-alcoholic fatty liver disease by inhibiting TGF-β/Smad signaling activation
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作者 Qingwei zhang Wenjie Zhao +8 位作者 Zeqi Sun Xinxin Dong Liwei Zhu zhen zhang Ximing Chen Yingying Hu Menghan Du Jiamin Li Yong zhang 《Frigid Zone Medicine》 2024年第1期12-22,共11页
Background:Nonalcoholic fatty liver disease(NAFLD)is a chronic condition characterized by a progressive decline in liver function,leading to disruptions in liver integrity and metabolic function,resulting in lipid dep... Background:Nonalcoholic fatty liver disease(NAFLD)is a chronic condition characterized by a progressive decline in liver function,leading to disruptions in liver integrity and metabolic function,resulting in lipid deposition and excessive accumulation of extracellular matrix(ECM).The pathogenesis of NAFLD is complex and not yet fully understood,contributing to the absence of specific therapeutic strategies.Peroxisome proliferator-activated receptor gamma(PPARγ)is a ligand-activated transcription factor pivotal in regulating lipid and glucose metabolism.However,the impacts of PPARγon NAFLD remains insufficiently explored.Thus,this study aimed to investigate the role of PPARγin NAFLD and its underlying molecular mechanisms.Methods:Chemical detection kits were utilized to quantify collagen content,alanine aminotransferase(ALT),and aspartate aminotransferase(AST)level variations.Quantitative real-time polymerase chain reaction(qRT-PCR)was employed to assess alterations in extracellular matrix-related genes and inflammatory response genes in liver tissue and HepG2 cells,while western blotting was conducted to analyze the levels of both PPARγand the TGF-β/Smad signaling pathway.Results:Our findings unveiled significantly reduced PPARγexpression in a rat model of NAFLD,leading to subsequent activation of the TGF-β/Smad signaling pathway.Furthermore,PPARγactivation effectively mitigated NAFLD progression by inhibiting inflammation and fibrosis-related gene expression and collagen production.On a cellular level,PPARγactivation was found to inhibit the expression of extracellular matrix-related genes such as matrix metalloproteinase 2(MMP2)and matrix metalloproteinase 9(MMP9),along with inflammatory response genes interleukin(IL)-1βand IL-6.Additionally,PPARγactivation led to a significant decrease in the levels of ALT and AST.At the molecular level,PPARγnotably down-regulated the TGF-β/Smad signaling pathway,which is known to promote liver fibrosis.Conclusion:These groundbreaking findings underscore PPARγactivation as a promising therapeutic approach to delay NAFLD progression by targeting the TGF-β/Smad signaling pathway in hepatic cells.This highlights the potential of PPARγas a promising therapeutic target for NAFLD management in clinical settings. 展开更多
关键词 NAFLD PPARΓ TGF-Β/SMAD liver fibrosis
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A Domain Question Answering Algorithm Based on the Contrastive Language-Image Pretraining Mechanism
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作者 Zuoxing zhang Dong Liang +2 位作者 zhen zhang Yang Cai Hongyi Hou 《Journal of Computer and Communications》 2023年第5期1-15,共15页
Research on specific domain question-answering technology has become important with the increasing demand for intelligent question-answering systems. This paper proposes a domain question-answering algorithm based on ... Research on specific domain question-answering technology has become important with the increasing demand for intelligent question-answering systems. This paper proposes a domain question-answering algorithm based on the CLIP mechanism to improve the accuracy and efficiency of interaction. First, this paper reviewed relevant technologies involved in the question-answering field. Then, the question-answering model based on the CLIP mechanism was produced, including its design, implementation, and optimization. It also described the construction process of the specific domain knowledge graph, including graph design, data collection and processing, and graph construction methods. The paper compared the performance of the proposed algorithm with classic question-answering algorithms BiDAF, R-Net, and XLNet models, using a military domain dataset. The experimental results show that the proposed algorithm has advanced performance, with an F1 score of 84.6% on the constructed military knowledge graph test set, which is at least 1.5% higher than other models. We conduct a detailed analysis of the experimental results, which illustrates the algorithm’s advantages in accuracy and efficiency, as well as its potential for further improvement. These findings demonstrate the practical application potential of the proposed algorithm in the military domain. 展开更多
关键词 QA system Knowledge Graph Domain Knowledge Knowledge Retrieval
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附子理中丸治疗肠结核作用机制的网络药理学研究 被引量:1
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作者 苏敏 钱纯 +4 位作者 张贞 姜思宇 李菁 李云豪 周辉 《世界华人消化杂志》 CAS 2023年第11期446-455,共10页
背景临床上常规结核化疗方案治疗肠结核副作用较大.附子理中丸是一种传统的治疗肠结核的中药.研究其具体的生物学作用机制有助于肠结核的治疗的进一步研究.目的基于网络药理学研究附子理中丸治疗肠结核的作用机制.方法在TCMSP数据库中... 背景临床上常规结核化疗方案治疗肠结核副作用较大.附子理中丸是一种传统的治疗肠结核的中药.研究其具体的生物学作用机制有助于肠结核的治疗的进一步研究.目的基于网络药理学研究附子理中丸治疗肠结核的作用机制.方法在TCMSP数据库中分别筛选附子理中丸5种主要药材的有效活性成分,并从TCMSP及Drugbank数据库中收集有效成分的作用靶点;在Genecards数据库收集肠结核相关的疾病靶点;通过Venny 2.1.0在线网站取药物活性成分作用靶点与疾病靶点的重叠靶点作为药物治疗肠结核的潜在治疗靶点;使用Cytoscape 3.9.1软件构建“药物-活性成分-靶点-疾病”网络;在String在线数据库中构建药物潜在治疗靶点的蛋白质互作(protein-protein interaction,PPI)网络,并通过Cytoscape 3.9.1软件进行拓扑学及可视化分析,进一步选取核心作用靶点;使用R4.1.2软件中的“clusterProfiler”程序包对潜在药物作用靶点进行京都基因和基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)富集分析和基因本体论(Gene Ontology,GO)分析.结果从公共数据库中一共收集了附子理中丸活性药物成分共108种,药物作用靶点254个,疾病靶点2579个;筛选出的药物潜在治疗靶点一共134个,核心靶点10个(AKT1、IL-6、TP53、VEGFA、IL1B、JUN、CASP3、PTGS2、PPARG、MAPK3);GO和KEGG富集分析提示附子理中丸治疗肠结核的生物学机制可能与细胞氧化应激、细胞因子参与的免疫调节相关,可能参与的功能通路包括白介素17信号通路、氧化应激通路等.结论附子理中丸治疗肠结核的作用机制与氧化应激、细胞因子参与的炎症或免疫调节相关,为日后的临床或基础研究提供了研究方向. 展开更多
关键词 肠结核 附子理中丸 网络药理学 细胞因子
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可降解高分子聚合物在仿生骨膜中的应用进展 被引量:1
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作者 刘子涛 周敏昌 +5 位作者 屈锐 赵伟名 张震 龙涛 胡旭麟 李开南 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第1期183-190,共8页
骨膜是骨骼生长的重要组成部分,覆盖在大多数骨骼的外表面,在骨缺损修复中起着中至关重要的作用。然而,由意外事故引起的骨折会引发骨膜的损伤,且由于自体骨膜和异体骨膜移植的免疫排斥反应、来源有限等问题使其在临床应用中受到极大的... 骨膜是骨骼生长的重要组成部分,覆盖在大多数骨骼的外表面,在骨缺损修复中起着中至关重要的作用。然而,由意外事故引起的骨折会引发骨膜的损伤,且由于自体骨膜和异体骨膜移植的免疫排斥反应、来源有限等问题使其在临床应用中受到极大的限制。因此,研究人员致力于开发一种与原生骨膜结构性能相似的仿生骨膜。文中综述了近年来可降解高分子聚合物在仿生骨膜中的研究进展,分别从仿生骨膜所用的可降解高分子聚合物材料、仿生骨膜的性能及制备方法3个方面进行综述,最后提出了一些当前的问题并进行了展望。 展开更多
关键词 仿生骨膜 可降解高分子聚合物 静电纺丝
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含硒杂环的电化学合成、分析及表征综合实验设计
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作者 张震 王世龙 +3 位作者 刘珊珊 李文佐 何涛 李家柱 《大学化学》 CAS 2023年第8期128-135,共8页
化学综合实验是学生开展创新实践训练的重要课程。笔者结合团队的科研成果,设计了一个电化学合成含硒杂环的综合实验。实验通过底物制备→电化学合成分析→结构表征→晶体培养解析等环节,对学生的合成操作、过程分析和结构解析等技能进... 化学综合实验是学生开展创新实践训练的重要课程。笔者结合团队的科研成果,设计了一个电化学合成含硒杂环的综合实验。实验通过底物制备→电化学合成分析→结构表征→晶体培养解析等环节,对学生的合成操作、过程分析和结构解析等技能进行系统训练。实验中的电化学合成思路有助于提升学生的绿色化学意识,激发实验学习兴趣。 展开更多
关键词 电化学 有机合成 绿色化学 单晶衍射
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Improving the anti-collapse performance of water-based drilling fluids of Xinjiang Oilfield using hydrophobically modified silica nanoparticles with cationic surfactants 被引量:1
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作者 He Li Xian-Bin Huang +3 位作者 Jin-Sheng Sun Kai-He Lv Xu Meng zhen zhang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第3期1768-1778,共11页
Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of... Wellbore instability,especially drilling with water-based drilling fluids(WBDFs)in complex shale for-mations,is a critical challenge for oil and gas development.The purpose of this paper is to study the feasibility of using hydrophobically modified silica nanoparticle(HMN)to enhance the comprehensive performance of WBDFs in the Xinjiang Oilfield,especially the anti-collapse performance.The effect of HMN on the overall performance of WBDFs in the Xinjiang Oilfield,including inhibition,plugging,lu-bricity,rheology,and filtration loss,was studied with a series of experiments.The mechanism of HMN action was studied by analyzing the changes of shale surface structure and chemical groups,wettability,and capillary force.The experimental results showed that HMN could improve the performance of WBDFs in the Xinjiang Oilfeld to inhibit the hydration swelling and dispersion of shale.The plugging and lubrication performance of the WBDFs in the Xinjiang Oilfield were also enhanced with HMN based on the experimental results.HMN had less impact on the rheological and filtration performance of the WBDFs in the Xinjiang Oilfield.In addition,HMN significantly prevented the decrease of shale strength.The potential mechanism of HMN was as follows.The chemical composition and structure of the shale surface were altered due to the adsorption of HMN driven by electrostatic attraction.Changes of the shale surface resulted in significant wettability transition.The capillary force of the shale was converted from a driving force of water into the interior to a resistance.In summary,hydrophobic nanoparticles presented afavorable application potential for WBDFs. 展开更多
关键词 Hydrophobic nanoparticle Wetting alteration Wellbore stability Water-based drilling fluids SHALE
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Antihepatoma peptide,scolopentide,derived from the centipede scolopendra subspinipes mutilans 被引量:1
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作者 Yu-Xing Hu Zhuo Liu +11 位作者 zhen zhang Zhe Deng zhen Huang Ting Feng Qing-Hong Zhou Si Mei Chun Yi Qing Zhou Pu-Hua Zeng Gang Pei Sha Tian Xue-Fei Tian 《World Journal of Gastroenterology》 SCIE CAS 2023年第12期1875-1898,共24页
BACKGROUND Centipedes have been used to treat tumors for hundreds of years in China.However,current studies focus on antimicrobial and anticoagulation agents rather than tumors.The molecular identities of antihepatoma... BACKGROUND Centipedes have been used to treat tumors for hundreds of years in China.However,current studies focus on antimicrobial and anticoagulation agents rather than tumors.The molecular identities of antihepatoma bioactive components in centipedes have not yet been extensively investigated.It is a challenge to isolate and characterize the effective components of centipedes due to limited peptide purification technologies for animal-derived medicines.AIM To purify,characterize,and synthesize the bioactive components with the strongest antihepatoma activity from centipedes and determine the antihepatoma mechanism.METHODS An antihepatoma peptide(scolopentide)was isolated and identified from the centipede scolopendra subspinipes mutilans using a combination of enzymatic hydrolysis,a Sephadex G-25 column,and two steps of high-performance liquid chromatography(HPLC).Additionally,the CCK8 assay was used to select the extracted fraction with the strongest antihepatoma activity.The molecular weight of the extracted scolopentide was characterized by quadrupole time of flight mass spectrometry(QTOF MS),and the sequence was matched by using the Mascot search engine.Based on the sequence and molecular weight,scolopentide was synthesized using solid-phase peptide synthesis methods.The synthetic scolopentide was confirmed by MS and HPLC.The antineoplastic effect of extracted scolopentide was confirmed by CCK8 assay and morphological changes again in vitro.The antihepatoma effect of synthetic scolopentide was assessed by the CCK8 assay and Hoechst staining in vitro and tumor volume and tumor weight in vivo.In the tumor xenograft experiments,qualified model mice(male 5-week-old BALB/c nude mice)were randomly divided into 2 groups(n=6):The scolopentide group(0.15 mL/d,via intraperitoneal injection of synthetic scolopentide,500 mg/kg/d)and the vehicle group(0.15 mL/d,via intraperitoneal injection of normal saline).The mice were euthanized by cervical dislocation after 14 d of continuous treatment.Mechanistically,flow cytometry was conducted to evaluate the apoptosis rate of HepG2 cells after treatment with extracted scolopentide in vitro.A Hoechst staining assay was also used to observe apoptosis in HepG2 cells after treatment with synthetic scolopentide in vitro.CCK8 assays and morphological changes were used to compare the cytotoxicity of synthetic scolopentide to liver cancer cells and normal liver cells in vitro.Molecular docking was performed to clarify whether scolopentide tightly bound to death receptor 4(DR4)and DR5.qRT-PCR was used to measure the mRNA expression of DR4,DR5,fas-associated death domain protein(FADD),Caspase-8,Caspase-3,cytochrome c(Cyto-C),B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),x-chromosome linked inhibitor-of-apoptosis protein and Cellular fas-associated death domain-like interleukin-1βconverting enzyme inhibitory protein in hepatocarcinoma subcutaneous xenograft tumors from mice.Western blot assays were used to measure the protein expression of DR4,DR5,FADD,Caspase-8,Caspase-3,and Cyto-C in the tumor tissues.The reactive oxygen species(ROS)of tumor tissues were tested.RESULTS In the process of purification,characterization and synthesis of scolopentide,the optimal enzymatic hydrolysis conditions(extract ratio:5.86%,IC_(50):0.310 mg/mL)were as follows:Trypsin at 0.1 g(300 U/g,centipede-trypsin ratio of 20:1),enzymolysis temperature of 46°C,and enzymolysis time of 4 h,which was superior to freeze-thawing with liquid nitrogen(IC_(50):3.07 mg/mL).A peptide with the strongest antihepatoma activity(scolopentide)was further purified through a Sephadex G-25 column(obtained A2)and two steps of HPLC(obtained B5 and C3).The molecular weight of the extracted scolopentide was 1018.997 Da,and the peptide sequence was RAQNHYCK,as characterized by QTOF MS and Mascot.Scolopentide was synthesized in vitro with a qualified molecular weight(1018.8 Da)and purity(98.014%),which was characterized by MS and HPLC.Extracted scolopentide still had an antineoplastic effect in vitro,which inhibited the proliferation of Eca-109(IC_(50):76.27μg/mL),HepG2(IC_(50):22.06μg/mL),and A549(IC_(50):35.13μg/mL)cells,especially HepG2 cells.Synthetic scolopentide inhibited the proliferation of HepG2 cells(treated 6,12,and 24 h)in a concentration-dependent manner in vitro,and the inhibitory effects were the strongest at 12 h(IC_(50):208.11μg/mL).Synthetic scolopentide also inhibited the tumor volume(Vehicle vs Scolopentide,P=0.0003)and weight(Vehicle vs Scolopentide,P=0.0022)in the tumor xenograft experiment.Mechanistically,flow cytometry suggested that the apoptosis ratios of HepG2 cells after treatment with extracted scolopentide were 5.01%(0μg/mL),12.13%(10μg/mL),16.52%(20μg/mL),and 23.20%(40μg/mL).Hoechst staining revealed apoptosis in HepG2 cells after treatment with synthetic scolopentide in vitro.The CCK8 assay and morphological changes indicated that synthetic scolopentide was cytotoxic and was significantly stronger in HepG2 cells than in L02 cells.Molecular docking suggested that scolopentide tightly bound to DR4 and DR5,and the binding free energies were-10.4 kcal/mol and-7.1 kcal/mol,respectively.In subcutaneous xenograft tumors from mice,quantitative real-time polymerase chain reaction and western blotting suggested that scolopentide activated DR4 and DR5 and induced apoptosis in SMMC-7721 Liver cancer cells by promoting the expression of FADD,caspase-8 and caspase-3 through a mitochondria-independent pathway.CONCLUSION Scolopentide,an antihepatoma peptide purified from centipedes,may inspire new antihepatoma agents.Scolopentide activates DR4 and DR5 and induces apoptosis in liver cancer cells through a mitochondria-independent pathway. 展开更多
关键词 SCOLOPENDRA CENTIPEDE Antihepatom peptide Hepatocellular carcinoma Death receptor 4 Death receptor 5
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Adversarial Training-Aided Time-Varying Channel Prediction for TDD/FDD Systems 被引量:1
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作者 zhen zhang Yuxiang zhang +1 位作者 Jianhua zhang Feifei Gao 《China Communications》 SCIE CSCD 2023年第6期100-115,共16页
In this paper, a time-varying channel prediction method based on conditional generative adversarial network(CPcGAN) is proposed for time division duplexing/frequency division duplexing(TDD/FDD) systems. CPc GAN utiliz... In this paper, a time-varying channel prediction method based on conditional generative adversarial network(CPcGAN) is proposed for time division duplexing/frequency division duplexing(TDD/FDD) systems. CPc GAN utilizes a discriminator to calculate the divergence between the predicted downlink channel state information(CSI) and the real sample distributions under a conditional constraint that is previous uplink CSI. The generator of CPcGAN learns the function relationship between the conditional constraint and the predicted downlink CSI and reduces the divergence between predicted CSI and real CSI.The capability of CPcGAN fitting data distribution can capture the time-varying and multipath characteristics of the channel well. Considering the propagation characteristics of real channel, we further develop a channel prediction error indicator to determine whether the generator reaches the best state. Simulations show that the CPcGAN can obtain higher prediction accuracy and lower system bit error rate than the existing methods under the same user speeds. 展开更多
关键词 channel prediction time-varying channel conditional generative adversarial network multipath channel deep learning
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The Relationship between Mental Health Literacy and Subjective Well-Being of Young and Middle-Aged Residents: Perceived the Mediating Role of Social Support and Its Urban-Rural Differences 被引量:1
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作者 zhen zhang Suyan Chen +4 位作者 Xiaoxuan Wang Jun Liu Yilin zhang Yongxia Mei zhenxiang zhang 《International Journal of Mental Health Promotion》 2023年第4期471-483,共13页
This study investigates mental health literacy among young and middle-aged urban and rural residents and the differences in mental health literacy,perceived social support and subjective well-being.From January to Feb... This study investigates mental health literacy among young and middle-aged urban and rural residents and the differences in mental health literacy,perceived social support and subjective well-being.From January to February 2022,620 participants(320 rural and 300 urban residents)from three provinces of China were selected by con-venience sampling.A general data questionnaire,mental health literacy scale,perceived social support scale and subjective well-being scale were administered.The mental health literacy scores of urban residents were 3.34±0.57 and those of rural residents were 2.73±0.79.The results of multiple regression analysis showed that the mental health literacy scores of rural residents were more significant than those of urban residents in terms of sex and age,while urban residents’mental health literacy scores were more significant than those of rural resi-dents in terms of monthly income.Mental health literacy,perceived social support and subjective well-being of young and middle-aged urban and rural residents were all positively correlated(P<0.01).While the level of mental health literacy is better among urban residents than rural residents,perceived social support plays a partial mediating role between mental health literacy and subjective well-being of both urban and rural residents,and should be the focus of researchers seeking to improve the level of well-being of residents. 展开更多
关键词 Young and middle-aged people mental health literacy perceived social support subjective well-being mediating role
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Deep learning-based activity recognition and fine motor identification using 2D skeletons of cynomolgus monkeys
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作者 Chuxi Li Zifan Xiao +11 位作者 Yerong Li Zhinan Chen Xun Ji Yiqun Liu Shufei Feng zhen zhang Kaiming zhang Jianfeng Feng Trevor W.Robbins Shisheng Xiong Yongchang Chen Xiao Xiao 《Zoological Research》 SCIE CSCD 2023年第5期967-980,共14页
Video-based action recognition is becoming a vital tool in clinical research and neuroscientific study for disorder detection and prediction.However,action recognition currently used in non-human primate(NHP)research ... Video-based action recognition is becoming a vital tool in clinical research and neuroscientific study for disorder detection and prediction.However,action recognition currently used in non-human primate(NHP)research relies heavily on intense manual labor and lacks standardized assessment.In this work,we established two standard benchmark datasets of NHPs in the laboratory:Monkeyin Lab(Mi L),which includes 13 categories of actions and postures,and MiL2D,which includes sequences of two-dimensional(2D)skeleton features.Furthermore,based on recent methodological advances in deep learning and skeleton visualization,we introduced the Monkey Monitor Kit(Mon Kit)toolbox for automatic action recognition,posture estimation,and identification of fine motor activity in monkeys.Using the datasets and Mon Kit,we evaluated the daily behaviors of wild-type cynomolgus monkeys within their home cages and experimental environments and compared these observations with the behaviors exhibited by cynomolgus monkeys possessing mutations in the MECP2 gene as a disease model of Rett syndrome(RTT).Mon Kit was used to assess motor function,stereotyped behaviors,and depressive phenotypes,with the outcomes compared with human manual detection.Mon Kit established consistent criteria for identifying behavior in NHPs with high accuracy and efficiency,thus providing a novel and comprehensive tool for assessing phenotypic behavior in monkeys. 展开更多
关键词 Action recognition Fine motor identification Two-stream deep model 2D skeleton Non-human primates Rett syndrome
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