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An Innovative Coupled Common-Node Discrete Element Method-Smoothed Particle Hydrodynamics Model Developed with LS-DYNA and Its Applications
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作者 SHEN Zhong-xiang WANG Wen-qing +2 位作者 XU Cheng-yue LUO Jia-xin LIU Ren-wei 《China Ocean Engineering》 SCIE EI CSCD 2024年第3期467-482,共16页
In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SP... In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SPH)method is developed using LS-DYNA software.The DEM and SPH are established on the same node to create common-node DEM-SPH particles,allowing for fluid–structure interactions.Numerical simulations of various scenarios,including water entry of a rigid sphere,dam-break propagation over wet beds,impact on an ice plate floating on water and ice accumulation on offshore structures,are conducted.The interaction between DS particles and SPH fluid and the crack generation mechanism and expansion characteristics of the ice plate under the interaction of structure and fluid are also studied.The results are compared with available data to verify the proposed coupling method.Notably,the simulation results demonstrated that controlling the cutoff pressure of internal SPH particles could effectively control particle splashing during ice crushing failure. 展开更多
关键词 common-node DEM-SPH fluid-structure interaction discrete element method smoothed particle hydrodynamics
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A modified smoothed particle hydrodynamics method considering residual stress for simulating failure and its application in layered rock mass
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作者 XIA Chengzhi SHI Zhenming KOU Huanjia 《Journal of Mountain Science》 SCIE CSCD 2024年第6期2091-2112,共22页
Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating fracture.An improved cracking strat... Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating fracture.An improved cracking strategy considering residual stress in the base bond SPH method was proposed to simulate failures in layered rocks and slopes and verified by experimental results and other simulation methods(i.e.,the discrete element method).Modified Mohr–Coulomb failure criterion was applied to distinguish the mixed failure of tensile and shear.Bond fracture markψwas introduced to improve the kernel function after tensile damage,and the calculation of residual stress after the damage was derived after shear damage.Numerical simulations were carried out to evaluate its performance under different stress and scale conditions and to verify its effectiveness in realistically reproducing crack initiation and propagation and coalescence,even fracture and separation.The results indicate that the improved cracking strategy precisely captures the fracture and failure pattern in layered rocks and rock slopes.The residual stress of brittle tock is correctly captured by the improved SPH method.The improved SPH method that considers residual strength shows an approximately 13%improvement in accuracy for the safety factor of anti-dip layered slopes compared to the method that does not consider residual strength,as validated against analytical solutions.We infer that the improved SPH method is effective and shows promise for applications to continuous and discontinuous rock masses. 展开更多
关键词 smoothed particle hydrodynamics Cracking strategy Residual stress Layered rock Crack propagation
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Comparative impact behaviours of ultra high performance concrete columns reinforced with polypropylene vs steel fibres
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作者 Thong M.Pham Harrison Hyde +4 位作者 Maw K.Kaung Yan Zhuge Duong T.Tran Des Vlietstra Tung M.Tran 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期138-153,共16页
Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacit... Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacity improvement. This study unveils the possibility of using PP micro-fibres to improve the impact behaviour of fibre-reinforced ultra-high-performance concrete(FRUHPC) columns. Results show that the addition of fibres significantly improves the impact behaviour of FRUHPC columns by shifting the failure mechanism from brittle shear to favourable flexural failure. The addition of steel or PP fibres affected the impact responses differently. Steel fibres considerably increased the peak impact force(up to 18%) while PP micro-fibres slightly increased the peak(3%-4%). FRUHPC significantly reduced the maximum midheight displacement by up to 30%(under 20°impact) and substantially improved the displacement recovery by up to 100%(under 20° impact). FRUHPC with steel fibres significantly improved the energy absorption while those with PP micro-fibres reduced the energy absorption, which is different from the effect of PP-macro fibre reported in the literature. The optimal fibre content for micro-PP fibres is 1% due to its minimal fibre usage and low peak and residual displacement. This study highlights the potential of FRUHPC as a promising material for impact-resistant structures by creating a more favourable flexural failure mechanism, enhancing ductility and toughness under impact loading, and advancing the understanding of the role of fibres in structural performance. 展开更多
关键词 ultra high-performance concrete Steel fibre Polypropylene micro-fibre Fibre volume fraction Impact loading Pendulum tests COLUMNS
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A Dual Domain Robust Reversible Watermarking Algorithm for Frame Grouping Videos Using Scene Smoothness
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作者 Yucheng Liang Ke Niu +1 位作者 Yingnan Zhang Yifei Meng 《Computers, Materials & Continua》 SCIE EI 2024年第6期5143-5174,共32页
The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grou... The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grouping videos.Grounded in the H.264 video coding standard,the algorithm first employs traditional robust watermark stitching technology to embed watermark information in the low-frequency coefficient domain of the U channel.Subsequently,it utilizes histogram migration techniques in the high-frequency coefficient domain of the U channel to embed auxiliary information,enabling successful watermark extraction and lossless recovery of the original video content.Experimental results demonstrate the algorithm’s strong imperceptibility,with each embedded frame in the experimental videos achieving a mean peak signal-to-noise ratio of 49.3830 dB and a mean structural similarity of 0.9996.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 7.59%and 0.4%on average.At the same time,the proposed algorithm has strong robustness to both offline and online attacks:In the face of offline attacks,the average normalized correlation coefficient between the extracted watermark and the original watermark is 0.9989,and the average bit error rate is 0.0089.In the face of online attacks,the normalized correlation coefficient between the extracted watermark and the original watermark is 0.8840,and the mean bit error rate is 0.2269.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 1.27%and 18.16%on average,highlighting the algorithm’s robustness.Furthermore,the algorithm exhibits low computational complexity,with the mean encoding and the mean decoding time differentials during experimental video processing being 3.934 and 2.273 s,respectively,underscoring its practical utility. 展开更多
关键词 Robust reversible watermarking scene smoothness dual-domain U channel H.264 encoding standard
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CO_(2) mineralization by typical industrial solid wastes for preparing ultrafine CaCO_(3): A review
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作者 Run Xu Fuxia Zhu +8 位作者 Liang Zou Shuqing Wang Yanfang Liu Jili Hou Chenghao Li Kuntong Song Lingzhao Kong Longpeng Cui Zhiqiang Wang 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第11期1679-1697,共19页
Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typ... Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies. 展开更多
关键词 Industrial solid wastes Resource utilization Mineral carbonation ultrafine CaCO_(3) Carbon emission reduction
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Smoothed-Particle Hydrodynamics Simulation of Ship Motion and Tank Sloshing under the Effect of Regular Waves
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作者 Mingming Zhao Jialong Jiao 《Fluid Dynamics & Materials Processing》 EI 2024年第5期1045-1061,共17页
Predicting the response of liquefied natural gas(LNG)contained in vessels subjected to external waves is extremely important to ensure the safety of the transportation process.In this study,the coupled behavior due to... Predicting the response of liquefied natural gas(LNG)contained in vessels subjected to external waves is extremely important to ensure the safety of the transportation process.In this study,the coupled behavior due to ship motion and liquid tank sloshing has been simulated by the Smoothed-Particle Hydrodynamics(SPH)method.Firstly,the sloshing flow in a rectangular tank was simulated and the related loads were analyzed to verify and validate the accuracy of the present SPH solver.Then,a three-dimensional simplified LNG carrier model,including two prismatic liquid tanks and a wave tank,was introduced.Different conditions were examined corresponding to different wave lengths,wave heights,wave heading angles,and tank loading rates.Finally,the effects of liquid tank loading rate on LNG ship motions and sloshing loading were analyzed,thereby showing that the SPH method can effectively provide useful indications for the design of liquid cargo ships. 展开更多
关键词 LNG carrier tank sloshing SEAKEEPING inner and external fluid coupling smoothed Particle Hydrodynamics(SPH)
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Spatiotemporal mapping of(ultra‐)mafic magmatic mine areas:Implications of economic and political realities in China
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作者 Heling Li Liang Tang +3 位作者 Tim T.Werner Zhengmeng Hou Fan Meng Jingjing Li 《Deep Underground Science and Engineering》 2024年第1期91-102,共12页
The spatiotemporal extension/expansion of mine areas is affected by multiple factors.So far,very little has been done to examine the interaction between mine areas and political or economic realities.The(ultra‐)mafic... The spatiotemporal extension/expansion of mine areas is affected by multiple factors.So far,very little has been done to examine the interaction between mine areas and political or economic realities.The(ultra‐)mafic magmatic mines in China played a specific role in supporting national development and providing an ideal research subject for monitoring their interrelationship.In this study,remote sensing and mining‐related GIS data were used to identify and analyze 1233(ultra‐)mafic magmatic mine area polygons in China,which covered approximately 322.96 km2 of land and included a V–Ti–Fe mine,a copper–nickel mine,a chromite mine,an asbestos mine,and a diamond mine.It was found that(1)the areal expansion of mines is significantly related to the mine types,perimeter,topography,and population density.(2)The mine area variation also reflects market and policy realities.The temporal expansion of the mine area from 2010 to 2020 followed an S‐shaped pattern(with the turning point occurring in 2014),closely related to iron overcapacity and tightened mining policies.(3)The complexity(D)of the mine area may reflect mine design and excavation practices.To be specific,lower D indicates early‐stage or artisanal/small‐scale mining,whereas higher D represents large‐scale mining.This study demonstrates that the detailed mapping of mine land can serve as an indicator to implement miningrelated market and policy changes.The(ultra‐)mafic mines area data set can be accessed at https://zenodo.org/record/7636616#.Y-p0uXaZOa0. 展开更多
关键词 complexity mine area mining and socioeconomic interaction spatiotemporal distribution (ultra‐)mafic magmatic mine
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Influence of Angiotensin II on α1-Adrenergic Receptors Function in Rat Aorta and Expression in Vascular Smooth Muscle Cells
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作者 Itzell Alejandrina Gallardo-Ortíz Juan Pablo de Jesús Benítez-Garrido +3 位作者 Santiago C. Sigrist-Flores Juan Javier López-Guerrero Enrique Hong Rafael Villalobos-Molina 《Journal of Biosciences and Medicines》 2024年第4期123-134,共12页
Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT<sub>1</sub> and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including func... Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT<sub>1</sub> and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including functioning as a growth factor, and as a contractile hormone, among others. The aim of this work was to examine the impact of Ang II on the expression and function of α<sub>1</sub>-adrenergic receptors (α<sub>1</sub>-ARs) in cultured rat aorta, and aorta-derived smooth muscle cells. Isolated Wistar rat aorta was incubated for 24 h in DMEM at 37˚C, then subjected to isometric tension and to the action of added norepinephrine, in concentration-response curves. Ang II was added (1 × 10<sup>−5</sup> M), and in some experiments, 5-Methylurapidil (α<sub>1A</sub>-AR antagonist), AH11110A (α<sub>1B</sub>-AR antagonist), or BMY-7378 (α<sub>1D</sub>-AR antagonist), were used to identify the α<sub>1</sub>-AR involved in the response. Desensitization of the contractile response to norepinephrine was observed due to incubation time, and by the Ang II action. α<sub>1D</sub>-AR was protected from desensitization by BMY-7378;while RS-100329 and prazosin partially mitigated desensitization. In another set of experiments, isolated aorta-derived smooth muscle cells were exposed to Ang II and α<sub>1</sub>-ARs proteins were evaluated. α<sub>1D</sub>-AR increased at 30 and 60 min post Ang II exposure, the α<sub>1A</sub>-AR diminished from 1 to 4 h, while α<sub>1B</sub>-AR remained unchanged over 24 h of Ang II exposure. Ang II induced an increase of α<sub>1D</sub>-AR at short times, and BMY-7378 protected α<sub>1D</sub>-AR from desensitization. 展开更多
关键词 Angiotensin II α1D-AR α1-AR Expression Rat aorta smooth Muscle Cells
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Xpert MTB/RIF Ultra在儿童结核诊断中的应用价值
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作者 王小杰 周正 《医药前沿》 2024年第18期23-26,共4页
目的:探讨Xpert MTB/RIF Ultra在儿童结核诊断中的应用价值。方法:选取2010年1月—2022年12月山东省公共卫生临床中心收治的150例患儿作为研究对象。根据临床综合诊断确诊结果将结核病感染患儿纳入试验组(n=100),将非结核病感染患儿纳... 目的:探讨Xpert MTB/RIF Ultra在儿童结核诊断中的应用价值。方法:选取2010年1月—2022年12月山东省公共卫生临床中心收治的150例患儿作为研究对象。根据临床综合诊断确诊结果将结核病感染患儿纳入试验组(n=100),将非结核病感染患儿纳入对照组(n=50)。计算不同标本类型的敏感度、特异度、阴性预测值、阳性预测值和准确度,评价Xpert MTB/RIF Ultra检出利福平(RIF)耐药性的效能。结果:Xpert MTB/RIF Ultra的检测所有标本总敏感度为77.00%,特异度为96.00%;合并肺内标本敏感度为92.85%,特异度为96.29%,其中肺内标本中肺泡灌洗液敏感度最高为100.00%;合并肺外标本敏感度为77.55%,特异度为95.65%,其中肺外标本中淋巴结敏感度最高为100.00%。结论:不同标本类型中Xpert MTB/RIF Ultra对儿童结核的检出率差异较大,在诊断肺内结核标本时,检测肺泡灌洗液标本价值最高,在诊断肺外结核标本时,检测淋巴结标本价值最高。 展开更多
关键词 儿童 结核 Xpert MTB/RIF ultra 标本
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A flexible multiscale algorithm based on an improved smoothed particle hydrodynamics method for complex viscoelastic flows
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作者 Jinlian REN Peirong LU +2 位作者 Tao JIANG Jianfeng LIU Weigang LU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第8期1387-1402,共16页
Viscoelastic flows play an important role in numerous engineering fields,and the multiscale algorithms for simulating viscoelastic flows have received significant attention in order to deepen our understanding of the ... Viscoelastic flows play an important role in numerous engineering fields,and the multiscale algorithms for simulating viscoelastic flows have received significant attention in order to deepen our understanding of the nonlinear dynamic behaviors of viscoelastic fluids.However,traditional grid-based multiscale methods are confined to simple viscoelastic flows with short relaxation time,and there is a lack of uniform multiscale scheme available for coupling different solvers in the simulations of viscoelastic fluids.In this paper,a universal multiscale method coupling an improved smoothed particle hydrodynamics(SPH)and multiscale universal interface(MUI)library is presented for viscoelastic flows.The proposed multiscale method builds on an improved SPH method and leverages the MUI library to facilitate the exchange of information among different solvers in the overlapping domain.We test the capability and flexibility of the presented multiscale method to deal with complex viscoelastic flows by solving different multiscale problems of viscoelastic flows.In the first example,the simulation of a viscoelastic Poiseuille flow is carried out by two coupled improved SPH methods with different spatial resolutions.The effects of exchanging different physical quantities on the numerical results in both the upper and lower domains are also investigated as well as the absolute errors in the overlapping domain.In the second example,the complex Wannier flow with different Weissenberg numbers is further simulated by two improved SPH methods and coupling the improved SPH method and the dissipative particle dynamics(DPD)method.The numerical results show that the physical quantities for viscoelastic flows obtained by the presented multiscale method are in consistence with those obtained by a single solver in the overlapping domain.Moreover,transferring different physical quantities has an important effect on the numerical results. 展开更多
关键词 multiscale method improved smoothed particle hydrodynamics(SPH) dissipative particle dynamics(DPD) multiscale universal interface(MUI) complex viscoelastic flow
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Xpert MTB/RIF Ultra对结核性脑膜炎的早期诊断价值
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作者 杨元利 张永峰 杨翰 《陕西医学杂志》 CAS 2024年第4期544-547,568,共5页
目的:评价Xpert MTB/RIF Ultra(Ultra)对结核性脑膜炎(TBM)的早期诊断价值。方法:对79例患者的临床资料进行分析,用Ultra、Xpert MTB/RIF(Xpert)、宏基因测序(mNGS)和分枝杆菌培养(MGIT)检测脑脊液(CSF)中的结核分枝杆菌。在临床诊断的... 目的:评价Xpert MTB/RIF Ultra(Ultra)对结核性脑膜炎(TBM)的早期诊断价值。方法:对79例患者的临床资料进行分析,用Ultra、Xpert MTB/RIF(Xpert)、宏基因测序(mNGS)和分枝杆菌培养(MGIT)检测脑脊液(CSF)中的结核分枝杆菌。在临床诊断的基础上,分析各方法的检测性能和利福平药物敏感性。结果:Ultra的敏感度(56.4%)、曲线下面积(AUC值)和Kappa值(0.521)均高于MGIT(20%、0.600、0.236)、Xpert(40%、0.700、0.236)和mNGS(32.7%、0.664、0.352)。在31例Ultra阳性病例中,24例对利福平敏感,7例耐药性不确定。结论:与其他方法相比,Ultra检测脑脊液中结核分枝杆菌具有较高的敏感性。因此,Ultra可用于TBM的早期诊断。 展开更多
关键词 脑脊液 诊断 结核性脑膜炎 Xpert MTB/RIF Xpert MTB/RIF ultra 宏基因测序
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Anisotropy of Trabecular Bone from Ultra-Distal Radius Digital X-Ray Imaging: Effects on Bone Mineral Density and Age
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作者 Jian-Feng Chen 《Open Journal of Radiology》 2024年第1期14-23,共10页
Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions... Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions parallel and perpendicular to the forearm. Methodology: Data from more than two hundred subjects were studied retrospectively. A DXA (GE Lunar Prodigy) scan of the forearm was performed on each subject to measure the bone mineral density (BMD) value at the location of ultra-distal radius, and an X-ray digital image of the same forearm was taken on the same day. The values of trabecular bone score along the direction perpendicular to the forearm, TBS<sub>x</sub>, and along the direction parallel to the forearm, TBS<sub>y</sub>, were calculated respectively. The statistics of TBS<sub>x</sub> and TBS<sub>y</sub> were calculated, and the anisotropy of the trabecular bone, which was defined as the ratio of TBS<sub>y</sub> to TBS<sub>x</sub> and changed with subjects’ BMD and age, was reported and analyzed. Results: The results show that the correlation coefficient between TBS<sub>x</sub> and TBS<sub>y</sub> was 0.72 (p BMD and age was reported. The results showed that decreased trabecular bone anisotropy was associated with deceased BMD and increased age in the subject group. Conclusions: This study shows that decreased trabecular bone anisotropy was associated with decreased BMD and increased age. 展开更多
关键词 ANISOTROPY Trabecular Bone Score Bone Mineral Density ultra-Distal Radius Digital X-Ray Image
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Microscopic study of ultrasound-mediated microbubble destruction effects on vascular smooth muscle cells 被引量:2
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作者 Bo Zhang Yi-Rong Hou +1 位作者 Tian Chen Bing Hu 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2015年第4期325-329,共5页
Objective:To observe vascular smooth muscle cell morphological changes induced by ultrasound combined with microbubbles by Atomic Force Acoustic Microscopy(AFAM).Methods:A7r5 rat aortic smooth muscle cells were divide... Objective:To observe vascular smooth muscle cell morphological changes induced by ultrasound combined with microbubbles by Atomic Force Acoustic Microscopy(AFAM).Methods:A7r5 rat aortic smooth muscle cells were divided into groups:control group(without ultrasonic irradiation,no micro bubbles)and US+MB group(45 kHz、0.4 W/cm^2 ultrasound irradiate for 20 seconds with a SonoVuc^(TM)concentration of[(56-140)×10~5/mL].Cell micromorphological changes(such as topographic and acoustic prognosis)were detected,before and after ultrasound destruction by AFAM.Results:In cell morphology,smooth muscle cells were spread o and connected to each another by fibers.At the center of the cell,the nuclear area had a rough surface and was significantly elevated from its surroundings.The cytoskeletal structure of the reticular nucleus and cytoplasm in the morphology of A7r5 cells(20μm×20μm)were clear before microbubble intervention.After acoustic exciting,the cell structure details of the acoustic image were improved with better resolution,showing the elasticity of different tissues.In the acoustic image,the nucleus was harder,more flexible and uneven compared with the cytoplasm.Many strong various-sized echo particles were stuck on the rough nuclear membrane's substrate surface.The nuclear membrane did not have a continuous smooth surface;there were many obstructions(pores).After ultrasound-intervention was combined with microbubbles,the dark areas of the A7r5 cell images was increased in various sizes and degrees.The dark areas showed the depth or low altitudes of the lower regions,suggesting regional depressions.However,the location and scope of the acoustic image dark areas were not similar to those found in the topographic images.Therefore,it was likely that the dark areas,both from the topographic and acoustic images,were sound-holes.In addition,some cell nuclei become round in different degrees after irradiation.Conclusions:Atomic force microscopy and acoustic excitation method can noninvasively and completely display a cell's structure,connections and elastic properties at a nano scale in just several minutes.The dark areas,both from the topographic and acoustic images,may be sound-holes;therefore,it would be helpful if these sound-holes were found.These findings provide a relationship between cell apoptosis after ultrasound and microbubble ultrasound irradiation,and the sound-hole effect. 展开更多
关键词 Atomic force acoustic microscopy VASCULAR smooth muscle cell ultraSOUND MICROBUBBLE
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A New Method for the Ultra-smooth Machining of the Silicon Based Materials
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作者 王波 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第S1期244-246,共3页
A New method,named atmospheric pressure plasma polishing,for the ultra-smooth machining of the silicon based materials is introduced.By inputting the CF4 gas into the atmospheric pressure plasma flame,high density rea... A New method,named atmospheric pressure plasma polishing,for the ultra-smooth machining of the silicon based materials is introduced.By inputting the CF4 gas into the atmospheric pressure plasma flame,high density reactive radicals will be generated,which will then react with the silicon based materials.The reaction product is the vaporization of the SiF4,which can be easily processed.In this way,the atomic scale material removal can be realized and the defect free ultra-smooth surface can be obtained.An experimental setup is built up,and the SiC polishing experiment is carried out.The AFM test result shows that the finished surface roughness (Ra) can be improved from 4.529 nm to 0.926 nm in 3 minutes. 展开更多
关键词 atmospheric pressure plasma silicon based materials ultra-smooth
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A novel approach to determine residual stress field during FSW of AZ91 Mg alloy using combined smoothed particle hydrodynamics/neuro-fuzzy computations and ultrasonic testing 被引量:2
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作者 A.R.Eivani H.Vafaeenezhad +1 位作者 H.R.Jafarian J.Zhou 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第4期1311-1335,共25页
The faults in welding design and process every so often yield defective parts during friction stir welding(FSW).The development of numerical approaches including the finite element method(FEM)provides a way to draw a ... The faults in welding design and process every so often yield defective parts during friction stir welding(FSW).The development of numerical approaches including the finite element method(FEM)provides a way to draw a process paradigm before any physical implementation.It is not practical to simulate all possible designs to identify the optimal FSW practice due to the inefficiency associated with concurrent modeling of material flow and heat dissipation throughout the FSW.This study intends to develop a computational workflow based on the mesh-free FEM framework named smoothed particle hydrodynamics(SPH)which was integrated with adaptive neuro-fiizzy inference system(ANFIS)to evaluate the residual stress in the FSW process.An integrated SPH and ANFIS methodology was established and the well-trained ANIS was then used to predict how the FSW process depends on its parameters.To verify the SPH calculation,an itemized FSW case was performed on AZ91 Mg alloy and the induced residual stress was measured by ultrasonic testing.The suggested methodology can efficiently predict the residual stress distribution throughout friction stir welding of AZ91 alloy. 展开更多
关键词 Friction stir welding(FSW) smoothed particle hydrodynamics(SPH) Adaptive neuro-fuzzy inference system(ANFIS) ultrasonic Residual stress
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Xpert MTB/RIF Ultra在快速检测结核分枝杆菌和利福平耐药中的应用 被引量:5
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作者 王垚 林珍丽 +1 位作者 陈新朝 黄明翔 《分子诊断与治疗杂志》 2023年第5期871-875,共5页
目的探讨Xpert MTB/RIF Ultra在快速检测结核分枝杆菌和利福平耐药中的应用价值。方法收集2019年12月至2020年5月就诊于福州肺科医院的447例疑似肺结核患者的痰标本,分别进行MGIT960液体培养及药敏、Xpert MTB/RIF(Xpert)和Xpert Ultra... 目的探讨Xpert MTB/RIF Ultra在快速检测结核分枝杆菌和利福平耐药中的应用价值。方法收集2019年12月至2020年5月就诊于福州肺科医院的447例疑似肺结核患者的痰标本,分别进行MGIT960液体培养及药敏、Xpert MTB/RIF(Xpert)和Xpert Ultra检测,将检出MTB的菌株和痰液进行rpoB基因Sanger测序。以临床诊断结果为参照,比较MGIT960液体培养、Xpert、Xpert Ultra检测MTB的敏感度和特异度;分别以液体药敏和测序结果为金标准,评价Xpert Ultra检测MTB利福平耐药性的效能。结果以临床确诊为参照,Xpert Ultra敏感度高于液体培养和Xpert,差异有统计学意义(χ^(2)=28.97、164.86,P均<0.05),特异度与液体培养和Xpert比较差异无统计学意义(P均>0.05)。分别以利福平液体药敏表型结果和rpoB基因测序结果为金标准,Xpert Ultra的敏感度为88.89%和93.75%。同时经测序分析,35例利福平耐药样本中,rpoB的531位点突变最为常见,占48.57%。结论Xpert Ultra能快速检测痰液中的MTB及其利福平耐药性,对肺结核早期诊疗有良好的临床应用价值,适合在各级实验室推广。 展开更多
关键词 Xpert MTB/RIF ultra 结核分枝杆菌 利福平 耐药
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A Study on the Effect of Low Calcium Ultra-fine Fly Ash as a Partial Sustainable Supplementary Material to Cement in Self-compacting Concrete 被引量:2
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作者 Adapala Sunny Suprakash Karthiyaini S 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第2期330-341,共12页
The aim and scope of the present study were to determine the efficacy of UFFA in evaluating the workability,static and dynamic stabilization properties,retention period,and slump loss of SCC systems in their fresh sta... The aim and scope of the present study were to determine the efficacy of UFFA in evaluating the workability,static and dynamic stabilization properties,retention period,and slump loss of SCC systems in their fresh state,as well as their compressive strength at various ages.Microstructure(SEM and XRD)of blended SCC systems were studied.Also,the thermogravimetry behavior of blended SCC specimens were researched.According to the evaluated results,incorporating up to 20%UFFA into fresh concrete improved its performance due to its engineered fine particle size and spherical geometry,both of which contribute to the enhancement of characteristics.Blends of 25%and 30%of UFFA show effect on the water-binder ratio and chemical enhancer dosage,resulting in a loss of homogeneity in fresh SCC systems.The reduced particle size,increased amorphous content,and increased surface area all contribute to the pozzolanic reactivity of the early and later ages,resulting in denser packing and thus an increase in compressive strength.The experimental results indicate that UFFA enhances the properties of SCC in both its fresh and hardened states,which can be attributed to the particles’fineness and their relative effect on SCC. 展开更多
关键词 ultra fine fly ash self-compacting concrete WORKABILITY SEGREGATION compressive strength microstructure TGA
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MicroRNA-146a Promotes Embryonic Stem Cell Differentiation towards Vascular Smooth Muscle Cells through Regulation of Kruppel-like Factor 4 被引量:2
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作者 Qing ZHANG Rong-rong PAN +1 位作者 Yu-tao WU Yu-miao WEI 《Current Medical Science》 SCIE CAS 2023年第2期223-231,共9页
Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis... Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis,and restenosis.MicroRNA-146a(miR-146a)has been proven to be involved in cell proliferation,migration,and tumor metabolism.However,little is known about the functional role of miR-146a in VSMC differentiation from embryonic stem cells(ESCs).This study aimed to determine the role of miR-146a in VSMC differentiation from ESCs.Methods Mouse ESCs were differentiated into VSMCs,and the cell extracts were analyzed by Western blotting and RT-qPCR.In addition,luciferase reporter assays using ESCs transfected with miR-146a/mimic and plasmids were performed.Finally,C57BL/6J female mice were injected with mimic or miR-146a-overexpressing ESCs,and immunohistochemistry,Western blotting,and RT-qPCR assays were carried out on tissue samples from these mice.Results miR-146a was significantly upregulated during VSMC differentiation,accompanied with the VSMC-specific marker genes smooth muscle-alpha-actin(SMαA),smooth muscle 22(SM22),smooth muscle myosin heavy chain(SMMHC),and h1-calponin.Furthermore,overexpression of miR-146a enhanced the differentiation process in vitro and in vivo.Concurrently,the expression of Kruppel-like factor 4(KLF4),predicted as one of the top targets of miR-146a,was sharply decreased in miR-146a-overexpressing ESCs.Importantly,inhibiting KLF4 expression enhanced the VSMC-specific gene expression induced by miR-146a overexpression in differentiating ESCs.In addition,miR-146a upregulated the mRNA expression levels and transcriptional activity of VSMC differentiation-related transcription factors,including serum response factor(SRF)and myocyte enhancer factor 2c(MEF-2c).Conclusion Our data support that miR-146a promotes ESC-VSMC differentiation through regulating KLF4 and modulating the transcription factor activity of VSMCs. 展开更多
关键词 microRNA-146a embryonic stem cells DIFFERENTIATION vascular smooth muscle cells Kruppel-like factor 4
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Inhibitory Effect of PPARδAgonist GW501516 on Proliferation of Hypoxia-induced Pulmonary Arterial Smooth Muscle Cells by Regulating the mTOR Pathway 被引量:1
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作者 Chang-gui CHEN Chun-feng YI +5 位作者 Chang-fa CHEN Li-qun TIAN Li-wei LI Li YANG Zuo-min LI Li-qun HE 《Current Medical Science》 SCIE CAS 2023年第5期979-987,共9页
Objective This study aimed to investigate the effects of the peroxisome proliferator-activated receptorδ(PPARδ)agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells(PASMCs)induced by hypoxia,... Objective This study aimed to investigate the effects of the peroxisome proliferator-activated receptorδ(PPARδ)agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells(PASMCs)induced by hypoxia,in order to search for new drugs for the treatment and prevention of pulmonary vascular remodeling.Methods PASMCs were incubated with different concentrations of GW501516(10,30,100 nmol/L)under the hypoxic condition.The proliferation was determined by a CCK-8 assay.The cell cycle progression was analyzed by flow cytometry.The expression of PPARδ,S phase kinase-associated protein 2(Skp2),and cell cycle-dependent kinase inhibitor p27 was detected by Western blotting.Then PASMCs were treated with 100 nmol/L GW501516,100 nmol/L mammalian target of rapamycin(mTOR)inhibitor rapamycin and/or 2µmol/L mTOR activator MHY1485 to explore the molecular mechanisms by which GW501516 reduces the proliferation of PASMCs.Results The presented data demonstrated that hypoxia reduced the expression of PPARδin an oxygen concentration-and time-dependent manner,and GW501516 decreased the proliferation of PASMCs induced by hypoxia by blocking the progression through the G0/G1 to S phase of the cell cycle.In accordance with these findings,GW501516 downregulated Skp2 and upregulated p27 in hypoxia-exposed PASMCs.Further experiments showed that rapamycin had similar effects as GW501516 in inhibiting cell proliferation,arresting the cell cycle,regulating the expression of Skp2 and p27,and inactivating mTOR in hypoxia-exposed PASMCs.Moreover,MHY1485 reversed all the beneficial effects of GW501516 on hypoxia-stimulated PASMCs.Conclusion GW501516 inhibited the proliferation of PASMCs induced by hypoxia through blocking the mTOR/Skp2/p27 signaling pathway. 展开更多
关键词 peroxisome proliferator-activated receptorδ GW501516 HYPOXIA pulmonary artery smooth muscle cells PROLIFERATION mammalian target of rapamycin
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Xpert MTB/RIF Ultra快速诊断涂阴肺结核的临床价值 被引量:8
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作者 丁彩红 王余余 +3 位作者 王庆 高绪胜 解丹 熊瑜 《解放军医学杂志》 CAS CSCD 北大核心 2023年第7期761-767,共7页
目的评估超敏结核分枝杆菌和利福平耐药基因检测(XpertUltra)方案检测痰液及支气管肺泡灌洗液(BALF)标本在涂阴肺结核患者中早期、快速诊断的价值。方法选择2020年5月-2021年12月在山东省公共卫生临床中心就诊的痰涂片阴性疑似肺结核患... 目的评估超敏结核分枝杆菌和利福平耐药基因检测(XpertUltra)方案检测痰液及支气管肺泡灌洗液(BALF)标本在涂阴肺结核患者中早期、快速诊断的价值。方法选择2020年5月-2021年12月在山东省公共卫生临床中心就诊的痰涂片阴性疑似肺结核患者93例,其中临床诊断为涂阴肺结核57例,非肺结核36例。收集所有患者的痰液及BALF标本,分别采用Xpert Ultra、GeneXpert MTB/RIF(Xpert)、BACTEC MGIT 960培养(MGIT 960培养)进行检测。以临床诊断为参考标准,评价3种检测方案及相互联合检测痰液及BALF标本时诊断涂阴肺结核的敏感度、特异度及符合率。结果以临床诊断结果为参考标准,Xpert Ultra检测痰液标本对涂阴肺结核诊断的敏感度明显高于Xpert[56.14%(32/57)vs.36.84%(21/57),P=0.03]和MGIT960培养[56.14%(32/57)vs.33.33%(19/57),P=0.014];Xpert Ultra检测BALF标本对涂阴肺结核诊断的敏感度明显高于Xpert[75.44%(43/57)vs.56.14%(32/57),P=0.030]和MGIT960培养[75.44%(43/57)vs.38.60%(22/57),P<0.01]。3种检测方案及相互联合检测痰液标本诊断涂阴肺结核,受试者工作特征(ROC)曲线下面积(AUC)依次为:三者联合(0.807)>Xpert Ultra+Xpert(0.798)>Xpert Ultra+MGIT 960培养(0.789)>Xpert Ultra(0.781)>Xpert(0.684)>MGIT 960培养(0.667);检测BALF标本,AUC依次为:三者联合(0.895)=Xpert Ultra+Xpert(0.895)>XpertUltra+MGIT960培养(0.877)=XpertUltra(0.877)>Xpert(0.781)>MGIT960培养(0.693)。3种检测方案均未在入组患者中检测到利福平耐药。结论Xpert Ultra对早期、快速诊断涂阴肺结核具有较高的临床应用价值;其检测BALF的敏感度高于痰液标本,建议优先选择BALF标本。 展开更多
关键词 超敏结核分枝杆菌和利福平耐药基因检测 涂阴肺结核 分子诊断技术 耐药 早期诊断
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