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Biomechanical comparison of cervical transfacet pedicle screws versus pedicle screws

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Chinese Medical Journal 2008年第15期121卷 1390-1393页

作者： LIU Guan-yi XU rong-ming ma wei-hu SUN Shao-hua HUANG Lei YING Jiang-wei JIANG wei-yu Department of Orthopaedics Ningbo Sixth People's Hospital Ningbo Zhejiang 315040 China

Background Transfacet pedicle screws provide another alternative for standard pedicle screw placement for plate fixation in the lumbar spine. However, few studies looking at transfacet pedicle screw fixation in the cervical spine are available. Therefore, cervical transfacet pedicle screw fixation and standard pedicle screw fixation techniques were biomechanically compared in this study. Methods Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels. On the other side, pedicle screws were placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50° caudally in the sagittal plane and about 45° toward the midline in the axial plane. Screws were placed from the inferior articular process, across the facet complex and the pedicle into the body of the caudal vertebra. The entry point for the pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass, and the direction of the screw was about 45° toward the midline in the axial plane and toward the upper third of the vertebral body in the sagittal plane. After screw placement we performed axial pullout testing. Results All the cervical transfacet pedicle screws and the pedicle screws were inserted successfully. The mean pullout strength for the transfacet pedicle screws was 694 N, while for the pedicle screws 670 N （P=0.013）. In all but six instances （10%）, the pedicle screw pullout values exceeded the values for the transfacet pedicle screws; this occurred three times at the C3/C4 level, twice at the C5/C6 level and once at the C7/T1 level. The greatest pullout strength difference at a single level was observed at the C5/C6 level, with a mean difference of 38 N （t=-1

关键词： cervical spine fixation transfacet pedicle screws pedicle screws

A Wind Tunnel Experimental Study on the Wake Characteristics of a Horizontal Axis Wind Turbine

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Journal of Thermal Science 2025年第1期34卷 145-158页

作者： GUO Xingduo LI Yinran LI Rennian ma Yulong wei Kui College of Energy and Power Engineering Lanzhou University of Technology Key Laboratory of Fluid machinery and Systems Gansu Provincial Technology Centre for Wind Turbines

The characteristics of wind turbine wakes are influenced by multiple factors,including the atmospheric boundary layer(ABL) wind and wind turbine operating conditions(e.g.,tip speed ratio and yaw angle).In this study,two types of ABL winds with different velocity gradients and turbulence intensities are generated in a wind tunnel through configurations of spires,baffles,and various numbers of roughness elements.A wind turbine with a rotor diameter of 0.8 m and a hub height of 0.6 m is tested under varying tip speed ratios,yaw angles,and ABL wind *** results indicate that the streamwise velocity deficit in the near-wake region becomes more pronounced with an increase in the tip speed ratio,while the far-wake velocity deficit remains largely unaffected by changes in the tip speed *** the yaw angle increases,the wake deflection becomes more prominent and the wake narrows;the offset of the wake center at various downstream positions grows linearly,reaching a maximum value of approximately half the rotor ***,the turbulence level and influence range in the wake region are reduced when the turbine is *** ABL wind conditions,high turbulence intensity in the incoming flow accelerates wake recovery,and the Reynolds stress at different lateral positions tends to become consistent with increasing longitudinal ***,turbulence has a significant impact on the meandering characteristics of the wind turbine wake,with greater fluctuations in the wake center observed under higher turbulence ***,this study provides insights that could inform the optimal operation of wind farms.

关键词： horizontal axis wind turbine turbulence wind tunnel experiment wind turbine wake

Interaction of major facilitator superfamily domain containing 2A with the blood-brain barrier

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Neural Regeneration Research 2025年第8期20卷 2133-2152页

作者： Yilun ma Taiwei Dong Fei Luan Juanjuan Yang Feng Miao Peifeng wei College of Pharmacy and First Clinical Medical College Shaanxi University of Chinese MedicineXianyangShaanxi ProvinceChina National Drug Clinical Trial Agency The Second Affiliated Hospital of Shaanxi University of Chinese Medicine/Xixian New District Central HospitalXi′anShaanxi ProvinceChina

The functional and structural integrity of the blood-brain barrier is crucial in maintaining homeostasis in the brain microenvironment;however,the molecular mechanisms underlying the formation and function of the blood-brain barrier remain poorly *** major facilitator superfamily domain containing 2A has been identified as a key regulator of blood-brain barrier *** plays a critical role in promoting and maintaining the formation and functional stability of the blood-brain barrier,in addition to the transport of lipids,such as docosahexaenoic acid,across the blood-brain ***,an increasing number of studies have suggested that major facilitator superfamily domain containing 2A is involved in the molecular mechanisms of blood-brain barrier dysfunction in a variety of neurological diseases;however,little is known regarding the mechanisms by which major facilitator superfamily domain containing 2A affects the blood-brain *** paper provides a comprehensive and systematic review of the close relationship between major facilitator superfamily domain containing 2A proteins and the blood-brain barrier,including their basic structures and functions,cross-linking between major facilitator superfamily domain containing 2A and the blood-brain barrier,and the in-depth studies on lipid transport and the regulation of blood-brain barrier *** comprehensive systematic review contributes to an in-depth understanding of the important role of major facilitator superfamily domain containing 2A proteins in maintaining the structure and function of the blood-brain barrier and the research progress to *** will not only help to elucidate the pathogenesis of neurological diseases,improve the accuracy of laboratory diagnosis,and optimize clinical treatment strategies,but it may also play an important role in prognostic *** addition,the effects of major facilitator superfamily domain containing 2A on blood-brain barrier lea

关键词： blood-brain barrier(BBB) caveolin-1 central nervous system docosahexaenoic acid endothelial cells lysophosphatidylcholine major facilitator superfamily domain containing 2A(MFSD2A) transcytosis

Morphology engineering of ZnO micro/nanostructures under mild conditions for optoelectronic application

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International Journal of Minerals,Metallurgy and materials 2025年第2期32卷 498-503页

作者： Liang Chu Haoyu Shen Hudie wei Hongyu Chen Guoqiang ma Wensheng Yan Institute of Carbon Neutrality and New Energy&School of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018China School of Applied Physics and materials Wuyi UniversityJiangmen 529020China

Zinc oxide(ZnO)serves as a crucial functional semiconductor with a wide direct bandgap of approximately 3.37 *** reaction is commonly used in the synthesis of ZnO micro/nanostructures,given its low cost,simplicity,and easy ***,ZnO morphology engineering has become desirable through the alteration of minor conditions in the reaction process,particularly at room *** this work,ZnO micro/nanostructures were synthesized in a solution by varying the amounts of the ammonia added at low temperatures(including room temperature).The formation of Zn^(2+)complexes by ammonia in the precursor regulated the reaction rate of the morphology engineering of ZnO,which resulted in various structures,such as nanoparticles,nanosheets,microflowers,and single ***,the obtained ZnO was used in the optoelectronic application of ultraviolet detectors.

关键词： morphology engineering low temperature ZnO nanosheets microflowers ultraviolet detector

Experimental Study for Effect of Multi-Site Spark Ignition on Dedicated Hybrid Engine Performance under High Dilution Condition

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Journal of Thermal Science 2025年第1期34卷 254-267页

作者： YAN Bowen WATERS Benjamin HAINES Andrew MCGHEE Mike HU Tiegang DENG wei PU Yongxian ma Tianyu Powertrain Engineering R&D Center Chongqing Changan Automobile Co.Ltd. Changan UK R&D Centre Limited

In this study,a triple spark ignition scheme was first designed on a three-cylinder 1.5-L dedicated hybrid engine（DHE）.On this basis,the effect of different ignition modes on engine combustion and emission characteristics was studied,especially under high dilution *** results tested at 2000 r/min and 0.8 MPa BMEP（brake mean effective pressure） show that with highly increased in-cylinder flow intensity,using only passive prechamber（PPC） has a lower lean limit than that with single central spark plug（CSP）,thereby leading to slightly higher minimum fuel consumption and nitrogen oxides（NOx） *** side spark plugs（SSP）based on PPC can result in improved capability of lean limit extension and engine performance than ***,the improvement level is lower than that with triple spark plugs（TSP）.As the excess air ratio λincreases,the advantage of PPC and PPC with SSP in improving the combustion phasing compared with CSP gradually ***,the increasing tendency of their ignition delay and combustion duration is more *** added SSP based on PPC can effectively shorten the ignition delay of leaner mixture,but the combustion duration can be only slightly *** a result,under extremely lean condition,the advantage of PPC and PPC with SSP in terms of combustion characteristics over CSP becomes much *** contrast,the TSP ignition can achieve much shorter ignition delay and combustion duration simultaneously under this *** to the highest available dilution level,the TSP ignition achieves the lowest raw ***,it can also reduce the raw carbon monoxide（CO） and hydrocarbons（HC） emissions compared to CSP due to a more thorough combustion of the end gas *** on the excellent performance of TSP,the highest engine brake thermal efficiency（BTE） was further *** results show that with normal RON 92 fuel,the engine finally achieved 43.69% and 45.02% BTE under stochiometric mode with exhaust

关键词： dedicated hybrid engine high dilution condition NOx emissions passive prechamber thermal efficiency triple spark plug scheme

Optimizing electronic structure through point defect engineering for enhanced electrocatalytic energy conversion

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Green Energy & Environment 2025年第1期10卷 109-131页

作者： wei ma Jiahao Yao Fang Xie Xinqi Wang Hao Wan Xiangjian Shen Lili Zhang Menggai Jiao Zhen Zhou Interdisciplinary Research Center for Sustainable Energy Science and Engineering(IRC4SE2) School of Chemical EngineeringZhengzhou UniversityHenan450001China

Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic *** introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active *** optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of *** elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization ***,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse *** underscores the pivotal role of point defects in enhancing catalytic *** last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.

关键词： Point defect engineering Doping Vacancy Electrocatalysis Electronic structure

不同雾化方法吸入布地奈德对慢性阻塞性肺疾病急性加重期患者胸肺顺应性及动脉血气指标的影响

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中国现代医学杂志 2017年第15期27卷 115-118页

作者：刘苔李娅杜卫祺马荣炜武警河北总队医院呼吸科河北石家庄050081

目的探讨不同雾化方法吸入布地奈德对慢性阻塞性肺疾病急性加重期(AECOPD)患者胸肺顺应性及动脉血气指标的影响。方法 83例慢阻肺急性加重期患者根据随机数字法分成两组,其中,40例采用空气泵驱动雾化治疗(空气泵驱动组),43例采用氧驱动... 详细信息

目的探讨不同雾化方法吸入布地奈德对慢性阻塞性肺疾病急性加重期(AECOPD)患者胸肺顺应性及动脉血气指标的影响。方法 83例慢阻肺急性加重期患者根据随机数字法分成两组,其中,40例采用空气泵驱动雾化治疗(空气泵驱动组),43例采用氧驱动雾化治疗(氧驱动组)。对慢阻肺症状评分(CAT)、血气分析指标及胸肺顺应性进行测定。结果治疗前后,空气泵驱动组及氧气驱动组雾化吸入布地奈德在CAT评分、胸肺顺应性(Ct、CI和Cth)、肺通气指标(FEV1.0、PEF、MIP和MEP)及血液酸碱度(pH)和动脉血氧分压(PaO)值2比较差异无统计学意义(P>0.05),但空气泵驱动组在改善PaCO_2水平上优于氧气驱动组(P<0.05)。结论孟鲁司特钠联合BiPAP呼吸机治疗哮喘-慢性阻塞性肺疾病重叠综合征有较好的临床疗效,值得推广和应用。

关键词：慢阻肺疾病布地奈德雾化吸入急性加重期

Microstructure Evolution and Mechanism of Strength Development of Fly Ash Paste

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Journal of Wuhan University of Technology(materials Science) 2025年第1期40卷 152-163页

作者： ma Shuzhao WU Shunchuan HUANG Mingqing CHENG Haiyong JIANG Guanzhao NIU Yonghui LIU Zemin SUN wei Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093China Zijin School of Ge-ology and Mining Fuzhou UniversityFuzhou 350108China

Three types of activators such as sodium hydroxide,calcium oxide and triethanolamine(TEA)are used to establish different activation environments to address the problems associated with the process of activating fly ash *** conducted mechanical tests and numerical simulations to understand the evolution of microstructure,and used environmental scanning electron microscopy(ESEM)and energy dispersive spectroscopy(EDS)techniques to analyze the microenvironments of the *** mechanical properties of fly ash paste under different activation conditions and the changes in the microstructure and composition were *** results revealed that under conditions of low NaOH content(1%-3%),the strength of the sample increased *** the content exceeded 4%,the rate of increase in strength *** on the results,the optimal NaOH content was identified,which was about 4%.A good activation effect,especially for short-term activation(3-7 d),was achieved using TEA under high doping *** activation effect was poor for long-term strength after 28 *** CaO content did not significantly affect the degree of activation *** maximum effect was exerted when the content of CaO was 2%.The virtual cement and concrete testing laboratory(VCCTL)was used to simulate the hydration process,and the results revealed that the use of the three types of activators accelerated the formation of Ca(OH)_(2) in the *** activators also corroded the surface of the fly ash particles,resulting in a pozzolanic *** active substances in fly ash were released efficiently,and hydration was *** pores were filled with hydration products,and the microstructure changed to form a new frame of paste filling that helped improve the strength of fly ash paste.

关键词： paste filling fly ash activator unconfined compressive strength microstructure hydration simulation

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

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Neural Regeneration Research 2025年第9期20卷 2598-2610页

作者： Yi Wang Yuning Li Yakun Gu wei ma Yuying Guan Mengyuan Guo Qianqian Shao Xunming Ji Jia Liu Department of Clinical Laboratory Beijing Bo’ai HospitalChina Rehabilitation Research CenterCapital Medical UniversityBeijingChina Beijing Institute of Brain Disorders Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Advanced Innovation Center for Big Data-based Precision MedicineCapital Medical UniversityBeijingChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina

Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this *** aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive *** found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic *** addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic *** phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic ***,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein *** ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein *** together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

关键词： biomarker high-density lipoprotein ischemic stroke phosphorylatedα-synuclein poststroke cognitive impairment