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Ab initio study on crystal structure and phase stability of ZrC_(2) under high pressure

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Chinese Physics B 2021年第1期30卷 350-358页

作者： Yong-Liang Guo Jun-Hong Wei Xiao Liu xue-zhi ke Zhao-Yong Jiao School of Science and Henan key Laboratory of Wire and Cable Structures and Materials Henan Institute of TechnologyXinxiang 453003China School of Physics Henan Normal UniversityXinxiang 453007China School of Physics and Electronic Science East China Normal UniversityShanghai 200241China

The structural stabilities and crystal evolution behaviors of the hyper stoichiometric compound ZrC_(2)(carbon rich;C/Zr> 1.0) are studied under ambient and high pressure conditions using first-principles calculations in combination with the particle-swarm optimization *** viable structures of ZrC_(2) in P21/c,Cmmm,Cmc2_(1),P4_(2)/nmc,Immm and P6/mmm symmetries are *** structures are dynamically stable as their phonon spectra have no imaginary modes at zero pressure or at the selected high-pressure *** them,the P21/c phase represents the ground state structure,whereas P21/c,P4_(2)/nmc,Immm and P6/mmm phases are part of the phase transition *** phase order and critical pressures of the phase transition are determined to be approximately 300 GPa according to the equation of states and ***,the mechanical and electronic properties are *** P21/c and Cmc2_(1) phases display a semi-metal nature,whereas the P4_(2)/nmc,Immm,P6/mmm and Cmmm phases exhibit a metallic ***,the present study reveals considerable information regarding the structural,mechanical and electronic properties of ZrC_(2),thereby providing key insights into its material properties and evaluating its behavior in practical applications.

关键词： crystal structure phase transition mechanical property electronic band first-principles calculation

Surface micro-arrays enhancing electromagnetic interference shielding of polydimethylsiloxane/multiwalled carbon nanotubes nanocomposites

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Nano Research 2025年第1期18卷 508-519页

作者： ke Jiang zhi Chen Ji Yu Chen Zheng Shan Huang Ming Wang Chongqing key Laboratory of Soft-Matter Material Manufacturing School of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China School of Mechanics Civil Engineering and ArchitecturesNorthwestern Polytechnical UniversityXi’an 710072China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China

Herein,the electromagnetic shielding performance of surface concave-convex(SC)and zig-zag micro-arrays was studied by using a simulation prediction and a three-dimensional(3D)printing custom ***,surface stripe concaveconvex(SSC)and surface cylindrical concave-convex(SCC)micro-arrays with or without zig-zag micro-arrays are designed,and their shielding performance is simulated in multi-bands(C-,X-band).The multiwalled carbon nanotubes/polydimethylsiloxane composites(MWCNT/PDMS)with different SC structures and different electrical conductivity are molded in acrylonitrile-butadiene-styrene copolymer(ABS)molds which are printed by a 3D *** results show that the electromagnetic interference shielding effectiveness(EMI SE)of the samples can be enhanced by constructing the SC micro-arrays with zig-zag micro-arrays,and improving with the increase of conductivity and *** addition,the shielding mechanism of the SC-MWCNT/PDMS composites is investigated and discussed by an electromagnetic simulation.

关键词： surface micro-arrays electrical properties electromagnetic interference(EMI)shielding three-dimensional(3D)printing

Real-world evidence on the efficacy and safety of vonoprazanamoxicillin dual therapy for Helicobacter pylori treatment in elderly patients

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World Journal of Gastroenterology 2025年第1期31卷 68-78页

作者： Wen Gao Jing-Wen Li Hui Ye xue-zhi Zhang Jian-Xiang Liu Hong Cheng Department of Gastroenterology Peking University First HospitalBeijing 100034China School of Medicine Tsinghua MedicineTsinghua UniversityBeijing 100034China Department of Traditional Chinese Medicine and Integrative Medicine Peking University First HospitalBeijing 100034China

BACKGROUND A dual therapy regimen containing amoxicillin is a common treatment option for the eradication of Helicobacter pylori(***).While substantial research supports the efficacy and safety of vonoprazan and amoxicillin(VA)dual therapy in the general population,there is still a lack of studies specifically focusing on its safety in elderly *** To evaluate efficacy and safety of VA dual therapy as first-line or rescue treatment for *** in elderly *** As a real-world retrospective study,data were collected from elderly patients aged 60 years and above who accepted VA dual therapy(vonoprazan 20 mg twice daily+amoxicillin 1000 mg thrice daily for 14 days)for *** eradication in the Department of Gastroenterology at Peking University First Hospital between June 2020 and January *** status was evaluated by^(13)C-urease breath test 6 weeks after *** adverse events(AEs)during treatment were *** In total,401 cases were ***-one cases were excluded due to loss to follow-up,lack of re-examination,or unwillingness to take *** total of 380 included cases comprised 250 who received VA dual therapy as first-line treatment and 130 who received VA dual therapy as rescue *** was successfully eradicated in 239 cases(95.6%)in the first-line treatment group and 116 cases(89.2%)in the rescue treatment *** overall incidence of AEs was 9.5%for both ***,9.2%of patients experienced an AE in the first-line treatment group and 10.0%in the rescue treatment *** patients discontinued treatment due to AE,with a discontinuation rate of 1.3%.No serious AE *** The VA dual therapy regimen as a first-line treatment and a rescue therapy was effective and safe for elderly patients aged 60 and older.

关键词： Helicobacter pylori Vonoprazan Amoxicillin Dual therapy Elderly

The complex roles of m^(6)A modifications in neural stem cell proliferation, differentiation, and self-renewal and implications for memory and neurodegenerative diseases

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Neural Regeneration Research 2025年第6期20卷 1582-1598页

作者： Yanxi Li Jing xue Yuejia Ma ke Ye xue Zhao Fangliang Ge Feifei Zheng Lulu Liu Xu Gao Dayong Wang Qing Xia Department of Biochemistry and Molecular Biology College of Basic Medical SciencesHarbin Medical UniversityHarbinHeilongjiang ProvinceChina College of Basic Medical Sciences Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Basic Medical Institute Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina key Laboratory of Heilongjiang Province for Genetically Modified Animals Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Translational Medicine Research and Cooperation Center of Northern China Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijingChina

N6-methyladenosine(m^(6)A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m^(6)A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m^(6)A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m^(6)A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m^(6)A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m^(6)A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m^(6)A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m^(6)A's role in neurodegenerative processes. The roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be a

关键词： Alzheimer's disease cell self-renewal central nervous system memory microglia nerve regeneration neurodegenerative diseases neurogenesis RNA methylation

135例非单纯Ph染色体的慢性髓系白血病细胞遗传学分析

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中国实验血液学杂志 2008年第5期16卷 997-1001页

作者：薛志科金洁陈志妹楼基余愈运彪桂林医学院附属医院血液内科广西桂林541001 浙江大学医学院第一附属医院血液内科浙江杭州310001

本研究探讨135例非单纯Ph染色体慢性髓系白血病(CML)的染色体检查结果并进行细胞遗传学分析。135例CML染色体均采用骨髓细胞直接法和/或短期培养法制备,应用R显带技术对其进行显带分析。结果表明:经染色体检测的1 210例的CML中135例有... 详细信息

本研究探讨135例非单纯Ph染色体慢性髓系白血病(CML)的染色体检查结果并进行细胞遗传学分析。135例CML染色体均采用骨髓细胞直接法和/或短期培养法制备,应用R显带技术对其进行显带分析。结果表明:经染色体检测的1 210例的CML中135例有非单纯Ph染色体异常。本组135例非单纯Ph染色体CML中,慢性期87例、加速期21例、急变期27例。87例慢性期患者中,14例伴简单变异易位,22例伴复杂变异易位,其余的伴其他染色体异常,其中伴8号染色体三体4例,伴双Ph4例,伴i(17)5例;在21例加速期患者中,伴8号染色体三体4例,伴双Ph4例,伴i(17)3例;在27例急变期患者中,2例伴简单变异易位,3例伴复杂变异易位,其余的伴其他染色体异常,其中伴8号染色体三体5例,伴双Ph5例,伴i(17)2例。本组常见额外染色体异常检出率高低依次为+Ph、+8、i(17)、-Y、+19和+21。本组有16例伴简单变异易位,25例伴复杂变异易位。结论:CML是起源于多能干细胞的恶性血液病。染色体核型分析对CML的诊断、预后、发病机制的探讨和治疗方案的选择都具有重要的价值。

关键词：慢性髓系白血病细胞遗传学 Ph染色体

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模块化多电平变流器孤网运行控制策略研究

电力电子技术 2017年第3期51卷 22-24页

作者：王帅荆龙吴学智李金科北京交通大学国家主动配电网技术研发中心北京100044 北京电动车辆协同创新中心北京100044

模块化多电平变流器(MMC)以其模块化的结构可使储能单元分散接入的优点,可作为微网系统孤网运行下的储能变流器。由于孤网系统具有大量的单相负荷,会导致输出电压不对称。研究了两相静止坐标系下MMC孤网运行的控制策略,分析了桥臂环流特... 详细信息

模块化多电平变流器(MMC)以其模块化的结构可使储能单元分散接入的优点,可作为微网系统孤网运行下的储能变流器。由于孤网系统具有大量的单相负荷,会导致输出电压不对称。研究了两相静止坐标系下MMC孤网运行的控制策略,分析了桥臂环流特性,并提出了相应的抑制方法。最后,经过仿真和实验验证了上述控制策略的有效性。

关键词：模块化多电平变流器孤网运行负载不平衡环流

刚/柔性障碍物对甲烷/空气预混气体泄爆动力学的影响

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安全与环境学报 2023年第4期23卷 1101-1107页

作者：陈先锋张椿城李毅许闯智雪珂武汉理工大学安全科学与应急管理学院武汉430070

为探究刚/柔性障碍物对甲烷/空气泄爆行为的影响,采用自主搭建的连接容器(20 L球形容器连接4 m长爆炸管道和0.5 m长泄压管道)试验系统,研究不同阻塞比与厚度的刚性/柔性障碍物对甲烷/空气爆炸超压及泄爆火焰的影响。结果表明,在球形容器... 详细信息

为探究刚/柔性障碍物对甲烷/空气泄爆行为的影响,采用自主搭建的连接容器(20 L球形容器连接4 m长爆炸管道和0.5 m长泄压管道)试验系统,研究不同阻塞比与厚度的刚性/柔性障碍物对甲烷/空气爆炸超压及泄爆火焰的影响。结果表明,在球形容器内,随阻塞比和厚度增加,峰值超压与最大升压速率相应增大,在阻塞率为80%和厚度为0.40 mm时峰值超压分别达到了190.4 kPa和273.5 kPa,最大升压速率分别为4.32 MPa/s和7.32 MPa/s。在管道末端,随柔性障碍物厚度增加,爆炸超压与升压速率同样大幅度提升。而随刚性障碍物阻塞比增加,峰值超压和最大升压速率先上升后下降。在设置刚性和柔性障碍物后,泄爆管道内均出现二次爆炸的现象,不同的是,二次爆炸的剧烈程度随柔性障碍物厚度增加而上升,而随刚性障碍物阻塞比增加呈现先增加后降低的趋势。

关键词：安全工程爆炸超压刚性障碍物柔性障碍物二次爆炸泄爆

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发生在活动区11931附近的重复喷流

天文学报 2015年第6期56卷 579-597页

作者：胡玉坤徐稚薛志科闫晓理申远灯吴宁林隽中国科学院云南天文台昆明650011 中国科学院大学北京100049 云南师范大学旅游与地理科学学院昆明650031

根据SDO/AIA(Solar Dynamics Observatory/Atmospheric Imaging Assembly)2013年12月25日到26日的171?A观测,发现在活动区NOAA 11931西南同一区域连续发生了一系列同源喷流事件,选取了其中的12次比较典型的喷流作了分析研究.与大部分喷流有关的磁场结构在抛射的过程中都有明显的解缠运动,少部分的几个没有.有的喷流的过程可以分为两个阶段:慢速无解缠抛射阶段和快速解缠抛射阶段.有的喷流在发生前,观测到有亮点沿着磁拱底部从远离喷流的一端向靠近喷流的一端延伸,而在喷流过程当中,靠近磁拱底部的区域有两部分磁力线同时在做旋转运动.在最后一次喷流过程中,喷流底部的磁结构东南端有两个磁拱先后出现,同时在西北端有一个小磁环浮现出来.对比SDO/HMI(Helioseismic and Magnetic Imager)的视向磁图发现,大约在第1次喷流出现之前4 h,一对正负磁极从有关磁结构的底部浮现,并且在整个喷流事件过程中一直在上浮.虽然在这12次喷流发生前后底部磁场整体上是浮现的,但是具体到每个喷流底部磁场的变化也不尽相同,有的喷流底部的磁拱附近磁场既有浮现过程又有对消过程,而有的喷流底部磁场附近只有明显磁浮现或者磁对消过程.

关键词：太阳:大气太阳:活动太阳:磁场拓扑结构

Role of nutrition in diabetes mellitus and infections

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World Journal of Clinical Cases 2025年第3期13卷 1-8页

作者： xue-Lu Yu Li-Yun Zhou Xiao Huang Xin-Yue Li Ming-ke Wang Ji-Shun Yang Naval Medical Center of PLA Naval Medical UniversityShanghai 200052China

In this editorial,we have commented on the article that has been published in the recent issue of World Journal of Clinical *** authors have described a case of unilateral thyroid cyst and have opined that the acute onset of infection may be linked to diabetes mellitus(DM).We have focused on the role of nutrition in the association between DM and *** with DM are at a high risk of infection,which could also be attributed to nutrition-related *** interventions for patients with diabetes are mainly based on a low-calorie diet,which can be achieved by adhering to a low-carbohydrate ***,dietary fiber supplementation is recommended to maintain the diversity of the gut ***,high-quality protein can prevent the increased risk of infection due to *** of vitamins C,vitamins A,vitamins D,and folic acid improves blood sugar control and facilitates immune *** deficiencies augment the risk of infection,but the relationship with diabetes is mostly U-shaped and a good intake should be maintained.

关键词： Diabetes mellitus Infection Macronutrients Vitamins Minerals