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Simulation study on cuttings transport of the backreaming operation for long horizontal section wells

Petroleum Science 2024年第2期21卷 1149-1170页

作者： Yu-Fei Chen Hui Zhang Wen-xin Wu Jun Li Yong Ouyang Zong-Yu Lu De-xin Ma Yong-Chuan Wu Jun-Bo Liu Ke-Rou Liu zhuo-xin Dong China University of Petroleum(Beijing) Beijing102249China Beijing Normal University at Zhuhai Experimental and Practical Education Innovation CenterZhuhai519087GuangdongChina Oil&Gas Technology Research Institute of PetroChina Changqing Oilfield Company Xi'an710016ShaanxiChina PetroChina xinjiang Oilfield Company Karamay834002XinjiangChina China Oilfield Services Ltd. Tianjin300459China

The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than

关键词： Backreaming Stuck pipe Hole cleaning Transient solid transport Multiple flow patterns

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Genome editing of PAR2 through targeted delivery of CRISPR-Cas9 system for alleviating acute lung inflammation via ERK/NLRP3/IL-1β and NO/iNOS signalling

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Acta Pharmaceutica Sinica B 2024年第3期14卷 1441-1456页

作者： xin zhuo Yue Wu Xiujuan Fu Jianbin Li Yuxin Xiang Xiaoyu Liang Canquan Mao Yuhong Jiang Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs School of Life Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Excessive and uncontrollable inflammatory responses in alveoli can dramatically exacerbate pulmonary disease progressions through vigorous cytokine releases,immune cell infiltration and protease-driven tissue *** is an urgent need to explore potential drug strategies for mitigating lung ***-activated receptor 2(PAR2)as a vital molecular target principally participates in various inflammatory diseases via intracellular signal ***,it has been rarely reported about the role of PAR2 in lung *** study applied CRISPR-Cas9 system encoding Cas9 and sg RNA(p Cas9-PAR2)for PAR2 knockout and fabricated an anionic human serum albuminbased nanoparticles to deliver p Cas9-PAR2 with superior inflammation-targeting efficiency and stability(TAP/p Cas9-PAR2).TAP/p Cas9-PAR2 robustly facilitated p Cas9-PAR2 to enter and transfect inflammatory cells,eliciting precise gene editing of PAR2 in vitro and in ***,PAR2 deficiency by TAP/p Cas9-PAR2 effectively and safely promoted macrophage polarization,suppressed proinflammatory cytokine releases and alleviated acute lung inflammation,uncovering a novel value of *** also revealed that PAR2-mediated pulmonary inflammation prevented by TAP/p Cas9-PAR2was mainly dependent on ERK-mediated NLRP3/IL-1β and NO/i NOS ***,this work indicated PAR2 as a novel target for lung inflammation and provided a potential nanodrug strategy for PAR2 deficiency in treating inflammatory diseases.

关键词： Protease-activated receptor 2(PAR2) CRISPR-Cas9 Gene editing Inflammation Acute lung inflammation NLRP3 Nanoparticles Drug delivery

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框拼式竹管网格结构体系及工程实践

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建筑结构学报 2024年第3期45卷 43-51页

作者：卓新董石麟浙江大学建筑工程学院浙江杭州310058 浙江大学平衡建筑研究中心浙江杭州310007

为了解决竹管耐久性差导致原竹建筑使用寿命短、传统竹管结构的节点性能弱、现代竹管空间结构的造价高等问题,提出了由造价较低的标准紧固件连接直竹管所构成的框拼式竹管网格结构体系,所有节点仅需连接两根竹管的特征使其节点域获得了... 详细信息

为了解决竹管耐久性差导致原竹建筑使用寿命短、传统竹管结构的节点性能弱、现代竹管空间结构的造价高等问题,提出了由造价较低的标准紧固件连接直竹管所构成的框拼式竹管网格结构体系,所有节点仅需连接两根竹管的特征使其节点域获得了较充裕的增强空间,制作平面化的多边形框单元工艺简单,采用螺栓连接使结构成形的安装方法快捷方便,施工定位因仅需控制框单元角部的竖向坐标而极大地简化了复杂曲面结构的施工难度,且可通过原位替换劣化框单元的方法来延长结构的使用寿命。建成的柱面、球面和双曲抛物面等形式的工程,证明了该结构体系的可行性与合理性;提出了叠层和桁架两种增强型的结构形式,并采用组合构件的加载试验验证了增强形式对提高结构承载力和刚度的有效性。此外,指出了在新型结构研发中,提升生产过程的工业化水平和降低建造各环节的成本对于推广应用至关重要;建立竹管结构分析和设计理论还将面临材料非线性、几何非线性、界面接触等关键问题。

关键词：框拼式竹管网格结构节点形式多边形框单元结构安装延长使用寿命结构增强方法

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抗阴道毛滴虫靶点及药物研究进展

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中国寄生虫学与寄生虫病杂志 2024年第1期42卷 105-110,120页

作者：周欣黄翠兰岳池县人民医院妇产科四川岳池638300

阴道毛滴虫主要侵犯人体泌尿生殖系统,是临床常见非病毒性传播病原。口服甲硝唑是目前普遍采用的治疗手段,但长期单一使用造成阴道毛滴虫对甲硝唑的耐药性不断增强,因此迫切需要寻找替代疗法。本文对近年来抗阴道毛滴虫靶点及药物的相... 详细信息

阴道毛滴虫主要侵犯人体泌尿生殖系统,是临床常见非病毒性传播病原。口服甲硝唑是目前普遍采用的治疗手段,但长期单一使用造成阴道毛滴虫对甲硝唑的耐药性不断增强,因此迫切需要寻找替代疗法。本文对近年来抗阴道毛滴虫靶点及药物的相关研究进行归纳分析,重点介绍取得的新进展,以期为后续研究和应用提供参考。

关键词：阴道毛滴虫靶点药物研究进展

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Nanocavity enriched CuPd alloy with high selectivity for CO_(2) electroreduction toward C_(2)H_(4)

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Rare Metals 2024年第4期43卷 1513-1523页

作者： Ze-Yu Zhang Hai-Bin Wang Fei-Fei Zhang Jing-Wei Li xin-zhuo Hu Si-Wei Yan Yi-Ming Bai Xun Zhang Gu-Rong Shen Peng-Fei Yin Jing Yang Cun-Ku Dong Jing Mao Hui Liu Xi-Wen Du Institute of New-Energy Materials School of Materials Science and EngineeringTianjin UniversityTianjin300350China

Electrocatalysis of CO_(2)reduction reaction is an effective way to convert CO_(2)into high value-added products,but the selectivity of Cu-based catalysts for C2+products needs to be improved due to the high energy barrier of C-C ***,a viable catalyst design strategy to decrease energy barrier of C-C coupling should be put ***,a nanocavity-enriched CuPd single atom alloy(CuPd SAA)catalyst is designed to promote CC coupling *** faradaic efficiency of CuPd SAA for ethylene and C_(2+)reaches 75.6%and 85.7%at-0.7 V versus reversible hydrogen electrode(RHE),*** on the results given by in situ characterization,the porous hollow structure dramatically increases the ratio of the linear-bond*CO,thus enhancing the faradaic efficiency for *** functional theory(DFT)calculation reveals that the Pd doping can regulate the electronic structure of neighboring Cu atoms to decrease the energy barrier of C-C coupling,further improving the faradaic *** work provides a new idea for designing catalyst with high selectivity for ethylene.

关键词： Adsorption configuration C-C coupling CO_(2) electrocatalysis Ethylene Single atom alloy

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Experimental Study on the Bending Properties of Grouting Butt Joints Reinforced by Steel Plate Embedded in Bamboo Tube

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Journal of Renewable Materials 2022年第4期10卷 993-1005页

作者： Ting Huang xin zhuo College of Civil Engineering and Architecture Zhejiang UniversityHangzhou310058China

The construction of grouting butt joints of bamboo tubes is simple and ***,when the joint is bent,the low tensile strength of the mortar easily leads to cracking of the mortar prior to the failure of the bamboo *** this paper,a comparative test of the bending capacity was performed on grouting butt joints reinforced by nonperforated,fully perforated,and semiperforated steel plates embedded in bamboo tubes to obtain the loaddisplacement curves and ultimate bearing capacity of various *** strengthening effect of CFRP pasted on bamboo tubes was also *** results show that the opening at the end of the steel plate is beneficial to resist the slip between the mortar and steel plate,while the complete section in the middle of the steel plate is conducive to making full use of the tensile strength of the steel ***,it is best to insert the semiperforated steel plate with openings in the end and without openings in the middle into the mortar to enhance the bending properties of the grouting butt joint,which can make the failure mode of the joint change from brittle failure of mortar to ductile compression failure of bamboo *** addition,pasting CFRP sheets on the external wall of the bamboo tube helps to reduce the tensile stress of the mortar,while increasing the width of the steel plate can increase the bending moment of inertia of the mixture of the steel plate and *** two complementary measures are very effective in delaying the cracking of the bamboo tube and improving the bending capacity of the joint.

关键词： Bamboo tube butt joint grouting connection perforated steel plate enhancement measure

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Tensile force correction calculation method for prestressed construction of tension structures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第9期9卷 1201-1207页

作者： xin zhuo Guo-fa ZHANG Koichiro ISHIKAWA Dao-an LOU Department of Civtl Engmeermg Zhejiang University Hangzhou 310027 China Department of Architecture and Civil Engineering Fukui University Fukui 910-8507 Japan Zhejiang Zhancheng Construction Group Co. Ltd. Hangzhou 310005 China

Factors such as errors during the fabrication or construction of structural components and errors of calculation as- sumption or calculation methods, are very likely to cause serious deviation of many strings’ actual prestressing forces from the designed values during tension structure construction or service period, and further to threaten the safety and reliability of the structure. Aiming at relatively large errors of the prestressing force of strings in a tension structure construction or service period, this paper proposes a new finite element method (FEM), the "tensile force correction calculation method". Based on the measured prestressing forces of the strings, this new method applies the structure from the zero prestressing force status approach to the measured prestressing force status for the first phase, and from the measured prestressing force status approach to the designed prestressing force status for the second phase. The construction tensile force correction value for each string can be obtained by multi-iteration with FEM. Using the results of calculation, the strings’ tensile force correction by group and in batch will be methodic, simple and accurate. This new calculation method can be applied to the prestressed correction construction simulation analysis for tension structures.

关键词： Tension structures Prestressed construction High precision

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基于Src/PI3K/Akt信号通路研究草乌甲素抑制类风湿关节炎骨破坏的作用机制

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中国中药杂志 2024年第6期49卷 1438-1445页

作者：黄凤玉郭婉怡陈沛萍张昕卓李卓航黄荷兰林娜苏晓慧孔祥英中国中医科学院中药研究所北京100700 广州中医药大学科技创新中心广东广州510405

基于非受体酪氨酸激酶(sarcoma receptor coactivator,Src)/磷脂酰肌醇3⁃激酶(phosphatidylinositol 3⁃kinase,PI3K)/蛋白激酶B(protein kinase B,Akt)信号通路探索草乌甲素改善实验性类风湿关节炎(rheumatoid arthritis,RA)骨破坏的作用机制。通过GeneCards、PharmGKB和OMIM数据库收集RA骨破坏的关键靶点,利用SwissTargetPrediction和PharmMapper数据库收集草乌甲素的潜在靶点,借助Venny 2.1.0平台获得交集靶点,运用STRING数据库及Cytoscape 3.8.0进行蛋白互作(protein⁃protein interaction,PPI)网络构建及拓扑分析。在DAVID数据库进行基因功能注释(Gene Ontology,GO)和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)富集分析,运用AutoDock Vina对草乌甲素与关键靶点进行分子对接和结合能力预测。最后建立NF⁃κB配体受体激活物(receptor activator of nuclear factor⁃κB,RANKL)诱导体外破骨细胞分化模型,采用定量实时聚合酶连锁反应法(quantitative real⁃time polymerase chain reaction,qRT⁃PCR)检测相关靶点mRNA表达水平,免疫荧光法、蛋白免疫印迹法检测关键靶点蛋白表达水平。结果发现,药物⁃疾病靶点共29个,Src为草乌甲素抗RA骨破坏的核心靶点。KEGG富集分析发现草乌甲素可能通过调控Src/PI3K/Akt信号通路发挥抗RA骨破坏的作用。分子对接结果显示,草乌甲素与Src、磷脂酰肌醇⁃4,5⁃二磷酸3⁃激酶(phosphatidylinositol⁃4,5⁃diphosphate 3⁃kinase,PIK3CA)和Akt1均有较好的结合能力。实验验证结果显示,草乌甲素不仅剂量依赖性地抑制破骨细胞分化相关基因组织蛋白酶K(cathepsin K,CTSK)、基质金属蛋白酶⁃9(matrix metalloproteinase⁃9,MMP⁃9)mRNA的表达(P<0.01),还显著降低体外破骨细胞中p⁃c⁃Src、PI3K及p⁃Akt的表达(P<0.01)。综上,草乌甲素可能通过调控Src/PI3K/Akt信号通路抑制RA骨破坏。该研究为草乌甲素改善RA骨破坏提供实验支撑,也将为草乌甲素的临床应用奠定基础。

关键词：草乌甲素类风湿关节炎骨破坏 Src/PI3K/Akt信号通路

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Preparation,crystallization,and wetting of ZnO-Al_2O_3-B_2O_3-SiO_2 glass-ceramics for sealing to Kovar

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International Journal of Minerals,Metallurgy and Materials 2009年第5期16卷 586-591页

作者： Mao Wu xin-bo He zhuo-shen Shen Xuan-hui Qu School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

A novel type of ZnO-Al2O3-B2O3-SiO2 glass-ceramics sealing to Kovar in electronic packaging was developed, whose thermal expansion coefficient and electrical resistance are 5.2× 10^-6/℃ and over 1×10^13 Ω·cm, respectively. The major crystalline phases in the glass-ceramic seals were ZnAl2O4, ZnB2O4, and NaSiAl2O4. The dielectric resistance of the glass-ceramic could be remarkably enhanced through the control of alkali metal ions into crystal lattices. It was found that crystallization happened first on the surface of the sample, leaving the amorphous phase in the inner, which made the glass suitable for sealing. The glass-ceramic showed better wetting on the Kovar surface, and sealing atmosphere and temperature had great effect on the wetting angle. Strong interracial bonding was obtained, which was mainly attributed to the interracial reaction between SiO2 and FeO or Fe3O4.

关键词： electronic packaging materials glass-ceramic crystallization wetting sealing

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马钱子水提物改善Ⅱ型胶原诱导型类风湿关节炎大鼠骨破坏的作用及机制研究

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中国中药杂志 2024年第6期49卷 1421-1428页

作者：张昕卓苏晓慧康世奇袁蓓杨京航林娜孔祥英黄丰云南中医药大学中药学院云南昆明650500 中国中医科学院中药研究所北京100700

考察马钱子水提物(aqueous extract of Strychni Semen,SA)对Ⅱ型胶原诱导型关节炎(typeⅡcollagen⁃induced arthri⁃tis,CIA)大鼠骨破坏的作用机制。将SD大鼠随机分为正常组,模型组,SA低、中、高剂量组(2.85、5.70、11.40 mg·kg^(-1)),甲氨蝶呤组。除正常组外,其他各组均制备CIA模型。二次免疫后,SA低、中、高剂量组给予不同剂量的SA,每日1次,甲氨蝶呤组每3 d给药1次,正常组和模型组给予0.3%羟甲基纤维素钠(CMC⁃Na),连续28 d。每3 d进行关节炎临床评分。采用微计算机断层扫描技术(micro computed tomography,Micro⁃CT)评价骨破坏。通过苏木素⁃伊红(hematoxylin⁃eosin,HE)染色以及抗酒石酸酸性磷酸酶(tartrate⁃resistant acid phosphatase,TRAP)染色评价CIA大鼠关节组织病理学变化及破骨细胞数量。免疫组织化学法检测大鼠关节组织中白细胞介素⁃1β(interleukin⁃1β,IL⁃1β)的表达。免疫蛋白印记法检测大鼠关节组织中丝裂原活化蛋白激酶(mitogen⁃activated protein kinase,MAPK)、磷脂酰肌醇3⁃激酶(phosphatidylinositol 3⁃kinase,PI3K)/蛋白激酶B(pro⁃tein kinase B,Akt)信号通路关键蛋白的表达。结果显示,SA各剂量均能不同程度地改善CIA大鼠炎症关节的红、肿和关节畸形,降低临床评分,抑制滑膜炎症、血管翳、软骨侵蚀和骨破坏,并减少骨组织中TRAP阳性细胞数;Micro⁃CT结果显示SA能够升高骨密度、骨体积分数、骨小梁厚度、骨小梁数量,并降低骨表面体积比和骨小梁分离度。SA各剂量均能不同程度下调IL⁃1β、p⁃JNK、p⁃ERK、p⁃p38、PI3K、p⁃Akt蛋白表达水平。综上,SA能够改善CIA大鼠的疾病严重程度,减轻关节组织病理学和影像学改变,具有骨保护作用,其作用机制可能与抑制MAPK、PI3K/Akt信号通路过度活化有关。

关键词：马钱子类风湿关节炎 CIA大鼠骨破坏

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