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Inhibition of the NLRP3 inflammasome attenuates spiral ganglion neuron degeneration in aminoglycoside-induced hearing loss
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作者 Jia Fang Zhuangzhuang Li +8 位作者 Pengjun Wang Xiaoxu Zhang Song Mao Yini Li Dongzhen Yu Xiaoyan Li Yazhi Xing Haibo Shi Shankai Yin 《Neural Regeneration Research》 SCIE CAS 2025年第10期3025-3039,共15页
Aminoglycosides are a widely used class of antibacterials renowned for their effectiveness and broad antimicrobial spectrum.However,their use leads to irreversible hearing damage by causing apoptosis of hair cells as ... Aminoglycosides are a widely used class of antibacterials renowned for their effectiveness and broad antimicrobial spectrum.However,their use leads to irreversible hearing damage by causing apoptosis of hair cells as their direct target.In addition,the hearing damage caused by aminoglycosides involves damage of spiral ganglion neurons upon exposure.To investigate the mechanisms underlying spiral ganglion neuron degeneration induced by aminoglycosides,we used a C57BL/6J mouse model treated with kanamycin.We found that the mice exhibited auditory deficits following the acute loss of outer hair cells.Spiral ganglion neurons displayed hallmarks of pyroptosis and exhibited progressive degeneration over time.Transcriptomic profiling of these neurons showed significant upregulation of genes associated with inflammation and immune response,particularly those related to the NLRP3 inflammasome.Activation of the canonical pyroptotic pathway in spiral ganglion neurons was observed,accompanied by infiltration of macrophages and the release of proinflammatory cytokines.Pharmacological intervention targeting NLRP3 using Mcc950 and genetic intervention using NLRP3 knockout ameliorated spiral ganglion neuron degeneration in the injury model.These findings suggest that NLRP3 inflammasome-mediated pyroptosis plays a role in aminoglycoside-induced spiral ganglion neuron degeneration.Inhibition of this pathway may offer a potential therapeutic strategy for treating sensorineural hearing loss by reducing spiral ganglion neuron degeneration. 展开更多
关键词 DEGENERATION hearing loss macrophages Mcc950 neuroinflammation NLRP3 inflammasome OTOTOXICITY pyroptosis sensorineural hearing loss spiral ganglion neuron
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Performance analysis of single-focus phase singularity based on elliptical reflective annulus quadrangle-element coded spiral zone plates
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作者 臧华平 王宝珍 +7 位作者 郑程龙 魏来 范全平 王少义 杨祖华 周维民 曹磊峰 郭海中 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期441-448,共8页
Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we pr... Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we propose an efficient methodology to combine the merit of elliptical reflective zone plates(ERZPs) and the advantage of spiral zone plates(SZPs) in establishing a specific single optical element, termed elliptical reflective annulus quadrangle-element coded spiral zone plates(ERAQSZPs) to generate single-focus phase singularity. Differing from the abrupt reflectance of the ERZPs, a series of randomly distributed nanometer apertures are adopted to realize the sinusoidal reflectance. Typically, according to our physical design, the ERAQSZPs are fabricated on a bulk substrate;therefore, the new idea can significantly reduce the difficulty in the fabrication process. Based on the Kirchhoff diffraction theory and convolution theorem, the focusing performance of ERAQSZPs is calculated. The results reveal that apart from the capability of generating optical vortices,ERAQSZPs can also integrate the function of focusing, energy selection, higher-order foci elimination, as well as high spectral resolution together. In addition, the focusing properties can be further improved by appropriately adjusting the parameters, such as zone number and the size of the consisted primitives. These findings are expected to direct a new direction toward improving the performance of optical capture, x-ray fluorescence spectra, and forbidden transition. 展开更多
关键词 optical vortex single-focus spiral zone plate topological charges
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Terahertz quasi-perfect vortex beam with integer-order and fractional-order generated by spiral spherical harmonic axicon
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作者 涂思语 刘德峰 +2 位作者 刘劲松 杨振刚 王可嘉 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期458-467,共10页
We propose a new method to generate terahertz perfect vortex beam with integer-order and fractional-order. A new optical diffractive element composed of the phase combination of a spherical harmonic axicon and a spira... We propose a new method to generate terahertz perfect vortex beam with integer-order and fractional-order. A new optical diffractive element composed of the phase combination of a spherical harmonic axicon and a spiral phase plate is designed and called spiral spherical harmonic axicon. A terahertz Gaussian beam passes through the spiral spherical harmonic axicon to generate a terahertz vortex beam. When only the topological charge number carried by spiral spherical harmonic axicon increases, the ring radius of terahertz vortex beam increases slightly, so the beam is shaped into a terahertz quasi-perfect vortex beam. Importantly, the terahertz quasi-perfect vortex beam can carry not only integer-order topological charge number but also fractional-order topological charge number. This is the first time that vortex beam and quasi-perfect vortex beam with fractional-order have been successfully realized in terahertz domain and experiment. 展开更多
关键词 TERAHERTZ spiral spherical harmonic axicon quasi-perfect vortex beam topological charge number
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Motorized spiral enteroscopy:A cautious step forward in technological innovation
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作者 Shu-Ping Xiao Hai Lin Hong-Bin Chen 《World Journal of Gastrointestinal Endoscopy》 2024年第11期581-586,共6页
With the continuous advancement in medical technology,endoscopy has gained significant attention as a crucial diagnostic tool.The introduction of motorized spiral enteroscopy(MSE)represents a significant advancement i... With the continuous advancement in medical technology,endoscopy has gained significant attention as a crucial diagnostic tool.The introduction of motorized spiral enteroscopy(MSE)represents a significant advancement in the diagnosis and treatment of small bowel diseases.While there are safety concerns and a high reliance on the operator’s skills,MSE should not be disregarded entirely.Instead,it should be considered as a supplementary endoscopic technique,particularly in situations where conventional endoscopy proves ineffective.Through continuous research and technical optimization,MSE has the potential to become an im-portant addition to the endoscopy toolbox in the future.We call on colleagues in the industry to work together to promote the improvement of MSE technology through continuous research and practice,with the aim to bring out its unique value in endoscopy while ensuring patient safety. 展开更多
关键词 Motorized spiral enteroscopy spiral enteroscopy Device-assisted enteroscopy ENDOSCOPY Small bowel diseases
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Device-assisted enteroscopy: Are we ready to dismiss the spiral?
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作者 Alessandro Mussetto Elettra Merola +7 位作者 Cesare Casadei Daniele Salvi Fabiola Fornaroli Silvia Cocca Margherita Trebbi Armando Gabbrielli Cristiano Spada Andrea Michielan 《World Journal of Gastroenterology》 SCIE CAS 2024年第26期3185-3192,共8页
Motorized spiral enteroscopy(MSE)is the latest advance in device-assisted enteroscopy.Adverse events related to MSE were discussed in a recent large systematic review and meta-analysis and were directly compared with ... Motorized spiral enteroscopy(MSE)is the latest advance in device-assisted enteroscopy.Adverse events related to MSE were discussed in a recent large systematic review and meta-analysis and were directly compared with those of balloon enteroscopy in a case-matched study and a randomized controlled trial.Following the real-life application of MSE,an unexpected safety issue emerged regarding esophageal injury and the technique has been withdrawn from the global market,despite encouraging results in terms of diagnostic and therapeutic yield.We conducted an Italian multicenter real-life prospective study,which was prematurely terminated after the withdrawal of MSE from the market.The primary goals were the evaluation of MSE performance(both diagnostic and therapeutic)and its safety in routine endoscopic practice,particularly in the early phase of introduction in the endoscopic unit.A subanalysis,which involved patients who underwent MSE after unsuccessful balloon enteroscopy,demonstrated,for the first time,the promising performance of MSE as a rescue procedure.Given its remarkable performance in clinical practice and its potential role as a backup technique following a previously failed enteroscopy,it may be more appropriate to refine and enhance MSE in the future rather than completely abandoning it. 展开更多
关键词 Motorized spiral enteroscopy Rescue enteroscopy Diagnostic yield Adverse events AGREE classification
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Study on the Relationship between Structural Aspects and Aerodynamic Characteristics of Archimedes Spiral Wind Turbines
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作者 Yuanjun Dai Zetao Deng +2 位作者 Baohua Li Lei Zhong Jianping Wang 《Fluid Dynamics & Materials Processing》 EI 2024年第7期1517-1537,共21页
A combined experimental and numerical research study is conducted to investigate the complex relationship between the structure and the aerodynamic performances of an Archimedes spiral wind turbine(ASWT).Two ASWTs are... A combined experimental and numerical research study is conducted to investigate the complex relationship between the structure and the aerodynamic performances of an Archimedes spiral wind turbine(ASWT).Two ASWTs are considered,a prototypical version and an improved version.It is shown that the latter achieves the best aerodynamic performance when the spread angles at the three sets of blades areα_(1)=30°,α_(2)=55°,α3=60°,respectively and the blade thickness is 4 mm.For a velocity V=10 m/s,a tip speed ratio(TSR)=1.58 and 2,the maximum CP values are 0.223 and 0.263 for the prototypical ASWT and improved ASWT,respectively,and the maximum C_(P) enhancement is 17.93%.For V=10 m/s and TSR=2,the CP values of the prototypical ASWT and improved ASWT are 0.225 and 0.263,respectively,with an aerodynamic performance enhancement of 16.88%.Through mutual verification of the test outcomes and numerical results,it is concluded that the proposed approach can effectively lead to aerodynamic performance improvement. 展开更多
关键词 Archimedes spiral wind turbine aerodynamic performance numerical calculation
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Fusion of Spiral Convolution-LSTM for Intrusion Detection Modeling
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作者 Fei Wang Zhen Dong 《Computers, Materials & Continua》 SCIE EI 2024年第5期2315-2329,共15页
Aiming at the problems of low accuracy and slow convergence speed of current intrusion detection models,SpiralConvolution is combined with Long Short-Term Memory Network to construct a new intrusion detection model.Th... Aiming at the problems of low accuracy and slow convergence speed of current intrusion detection models,SpiralConvolution is combined with Long Short-Term Memory Network to construct a new intrusion detection model.The dataset is first preprocessed using solo thermal encoding and normalization functions.Then the spiral convolution-Long Short-Term Memory Network model is constructed,which consists of spiral convolution,a two-layer long short-term memory network,and a classifier.It is shown through experiments that the model is characterized by high accuracy,small model computation,and fast convergence speed relative to previous deep learning models.The model uses a new neural network to achieve fast and accurate network traffic intrusion detection.The model in this paper achieves 0.9706 and 0.8432 accuracy rates on the NSL-KDD dataset and the UNSWNB-15 dataset under five classifications and ten classes,respectively. 展开更多
关键词 Intrusion detection deep learning spiral convolution long and short term memory networks 1D-spiral convolution
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Effectiveness of magnetic resonance imaging and spiral computed tomography in the staging and treatment prognosis of colorectal cancer
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作者 Lu-Na Bai Lu-Xian Zhang 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第7期2135-2144,共10页
BACKGROUND Colorectal cancer(CRC)is a prevalent cancer type in clinical settings;its early signs can be difficult to detect,which often results in late-stage diagnoses in many patients.The early detection and diagnosi... BACKGROUND Colorectal cancer(CRC)is a prevalent cancer type in clinical settings;its early signs can be difficult to detect,which often results in late-stage diagnoses in many patients.The early detection and diagnosis of CRC are crucial for improving treatment success and patient survival rates.Recently,imaging techniques have been hypothesized to be essential in managing CRC,with magnetic resonance imaging(MRI)and spiral computed tomography(SCT)playing a significant role in enhancing diagnostic and treatment approaches.AIM To explore the effectiveness of MRI and SCT in the preoperative staging of CRC and the prognosis of laparoscopic treatment.METHODS Ninety-five individuals admitted to Zhongshan Hospital Xiamen University underwent MRI and SCT and were diagnosed with CRC.The precision of MRI and SCT for the presurgical classification of CRC was assessed,and pathological staging was used as a reference.Receiver operating characteristic curves were used to evaluate the diagnostic efficacy of blood volume,blood flow,time to peak,permeability surface,blood reflux constant,volume transfer constant,and extracellular extravascular space volume fraction on the prognosis of patients with CRC.RESULTS Pathological biopsies confirmed the following CRC stages:23,23,32,and 17 at T1,T2,T3,and T4,respectively.There were 39 cases at the N0 stage,22 at N1,34 at N2,44 at M0 stage,and 51 at M1.Using pathological findings as the benchmark,the combined use of MRI and SCT for preoperative TNM staging in patients with CRC demonstrated superior sensitivity,specificity,and accuracy compared with either modality alone,with a statistically significant difference in accuracy(P<0.05).Receiver operating characteristic curve analysis revealed the predictive values for laparoscopic treatment prognosis,as indicated by the areas under the curve for blood volume,blood flow,time to peak,and permeability surface,blood reflux constant,volume transfer constant,and extracellular extravascular space volume fraction were 0.750,0.683,0.772,0.761,0.709,0.719,and 0.910,respectively.The corresponding sensitivity and specificity values were also obtained(P<0.05).CONCLUSION MRI with SCT is effective in the clinical diagnosis of patients with CRC and is worthy of clinical promotion. 展开更多
关键词 Magnetic resonance imaging spiral computed tomography Colorectal cancer PROGNOSIS Receiver operating characteristic curve Retrospective study
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Dark Matter Density Profiles of Selected Spiral Galaxies
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作者 Alberto Sadun Brittany Salmon +1 位作者 Conor Evans Masoud Asadi-Zeydabadi 《International Journal of Astronomy and Astrophysics》 2024年第3期172-183,共12页
Understanding the dark matter distribution throughout a galaxy can provide insight into its elusive nature. Numerous density profiles, such as the Navarro, Frenk and White model, have been created in an attempt to stu... Understanding the dark matter distribution throughout a galaxy can provide insight into its elusive nature. Numerous density profiles, such as the Navarro, Frenk and White model, have been created in an attempt to study this distribution through analyzing orbital velocities of luminous matter and modeling dark matter distributions to explain these observations. However, we are interested in a simple model to consider the significant fluctuations in rotation curves at larger radii. Therefore, our model is much simpler compared to those previously mentioned. Our model used all the observational data available for four selected galactic rotation curves. These data present a significant variation in the orbital velocity of matter at the same distances. By running real observational data through our model, we show that the density of the dark matter within them shows real complex structure, which is not suggested by other computational models. Our aim of this paper is to model this structure and then speculate as to the cause and implications of these density fluctuations. 展开更多
关键词 Dark Matter Density Galactic Rotation Curves spiral Galaxies NGC 2841 NGC 4527 NGC 4945 NGC 3198
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The Origin of the Flat Rotation Curves in Spiral Galaxies: The Hidden Roles of Glitching SMDEOs and Emission of Gravitational Waves
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作者 Ahmad A. Hujeirat Peter Berczik 《Journal of Modern Physics》 2024年第10期1523-1542,共20页
Supermassive DEOs (SMDEOs) are cosmologically evolved objects made of irreducible incompressible supranuclear dense superfluids: The state we consider to govern the matter inside the cores of massive neutron stars. Th... Supermassive DEOs (SMDEOs) are cosmologically evolved objects made of irreducible incompressible supranuclear dense superfluids: The state we consider to govern the matter inside the cores of massive neutron stars. These cores are practically trapped in false vacua, rendering their detection by outside observers impossible. Based on massive parallel computations and theoretical investigations, we show that SMDEOs at the centres of spiral galaxies that are surrounded by massive rotating torii of normal matter may serve as powerful sources for gravitational waves carrying away roughly 1042 erg/s. Due to the extensive cooling by GWs, the SMDEO-Torus systems undergo glitching, through which both rotational and gravitational energies are abruptly ejected into the ambient media, during which the topologies of the embedding spacetimes change from curved into flatter ones, thereby triggering a burst gravitational energy of order 1059 erg. Also, the effects of glitches found to alter the force balance of objects in the Lagrangian-L1 region between the central SMDEO-Torus system and the bulge, enforcing the enclosed objects to develop violent motions, that may explain the origin of the rotational curve irregularities observed in the innermost part of spiral galaxies. Our study shows that the generated GWs at the centres of galaxies, which traverse billions of objects during their outward propagations throughout the entire galaxy, lose energy due to repeatedly squeezing and stretching the objects. Here, we find that these interactions may serve as damping processes that give rise to the formation of collective forces f∝m(r)/r, that point outward, endowing the objects with the observed flat rotation curves. Our approach predicts a correlation between the baryonic mass and the rotation velocities in galaxies, which is in line with the Tully-Fisher relation. The here-presented self-consistent approach explains nicely the observed rotation curves without invoking dark matter or modifying Newtonian gravitation in the low-field approximation. 展开更多
关键词 General Relativity: Black Holes Neutron Stars Quantum Fields: QCD Condensed Matter INCOMPRESSIBILITY SUPERFLUIDITY Cosmology: Galaxy Formation spiral Galaxies Dark Matter Rotation Curves
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Time-Varying Mesh Stiffness Calculation and Dynamic Modeling of Spiral Bevel Gear with Spalling Defects
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作者 Keyuan Li Baijie Qiao +2 位作者 Heng Fang Xiuyue Yang Xuefeng Chen 《Journal of Dynamics, Monitoring and Diagnostics》 2024年第2期143-155,共13页
Time-varying mesh stiffness(TVMS)is a vital internal excitation source for the spiral bevel gear(SBG)transmission system.Spalling defect often causes decrease in gear mesh stiffness and changes the dynamic characteris... Time-varying mesh stiffness(TVMS)is a vital internal excitation source for the spiral bevel gear(SBG)transmission system.Spalling defect often causes decrease in gear mesh stiffness and changes the dynamic characteristics of the gear system,which further increases noise and vibration.This paper aims to calculate the TVMS and establish dynamic model of SBG with spalling defect.In this study,a novel analytical model based on slice method is proposed to calculate the TVMS of SBG considering spalling defect.Subsequently,the influence of spalling defect on the TVMS is studied through a numerical simulation,and the proposed analytical model is verified by a finite element model.Besides,an 8-degrees-of-freedom dynamic model is established for SBG transmission system.Incorporating the spalling defect into TVMS,the dynamic responses of spalled SBG are analyzed.The numerical results indicate that spalling defect would cause periodic impact in time domain.Finally,an experiment is designed to verify the proposed dynamic model.The experimental results show that the spalling defect makes the response characterized by periodic impact with the rotating frequency of spalled pinion. 展开更多
关键词 dynamic modeling slice method SPALLING spiral bevel gear time-varying mesh stiffness(TVMS)
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水平多层spiral型地埋管数值模拟研究及换热特性分析
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作者 高英 谷峰 +2 位作者 张越 崔景云 蒋时馨 《石化技术》 CAS 2024年第4期48-50,共3页
本文基于COMSOL软件建立了水平spiral型多层地埋管群传热三维数值模拟模型,并对其换热性能和温度场进行分析研究。结果表明:对比水平spiral多层并联管群来说,远离注入端的地埋管管内温度相对较低。地埋管群周围地层温度有所升高,远离注... 本文基于COMSOL软件建立了水平spiral型多层地埋管群传热三维数值模拟模型,并对其换热性能和温度场进行分析研究。结果表明:对比水平spiral多层并联管群来说,远离注入端的地埋管管内温度相对较低。地埋管群周围地层温度有所升高,远离注入端的地层温度变化相对较小。地埋管群的换热量随循环流体的流速增加而增加,但增幅降低。在进行换热器设计时,应合理控制循环水的流速。3层螺旋地埋管群的换热量略高,但层间干扰明显,建议选用2层并联螺旋管群。 展开更多
关键词 水平螺旋地埋管换热器 传热特性 数值模拟 多层 地埋管群
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儿童新型冠状病毒感染并发纵隔气肿八例影像学及临床特点研究
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作者 付强 任作雷 +5 位作者 林志强 龚剑峰 王长征 王婷 胡雅兰 谭举方 《中国全科医学》 CAS 北大核心 2025年第4期510-515,共6页
背景儿童新型冠状病毒感染(COVID-19)影像学与成人有一定差异,主要表现为胸膜下磨玻璃影、斑片状高密度影、实变影等,合并纵隔气肿者并不多见。大量气肿形成可严重影响呼吸及循环功能,导致明显喘憋、低氧血症,需积极处理。目的分析并总... 背景儿童新型冠状病毒感染(COVID-19)影像学与成人有一定差异,主要表现为胸膜下磨玻璃影、斑片状高密度影、实变影等,合并纵隔气肿者并不多见。大量气肿形成可严重影响呼吸及循环功能,导致明显喘憋、低氧血症,需积极处理。目的分析并总结儿童COVID-19并发纵隔气肿的影像学及临床特征。方法回顾分析2022-12-01—2023-01-30在长江大学附属荆州医院儿科住院的8例COVID-19并发纵隔气肿的患儿年龄、性别、影像学、临床特点及诊疗情况。结果8例患儿年龄3岁7个月~12岁,男女比3∶5,高分辨率CT(HRCT)均显示双肺感染合并纵隔气肿。气肿多同时累及颈部及胸壁。肺部表现多种多样:胸膜下磨玻璃影、实变、树芽征、支气管血管束增粗、支气管壁增厚及网格征等,未见大片实变及“白肺”。1例患儿合并少量胸腔积液。临床表现除有发热、咳嗽外,均有明显气促,肺部听诊干湿啰音可不显著。4例合并肺炎支原体感染、1例合并卡他布兰汉菌感染。合并肺炎支原体感染者应用阿奇霉素,合并卡他布兰汉菌感染者给予头孢噻肟治疗。8例患儿均给予氧疗。1例患儿白细胞总数及超敏C反应蛋白明显升高,明显气急,低氧血症,常规治疗无好转,给予有创呼吸机治疗3d后好转撤机。5例应用静脉丙种球蛋白(IVIG),3例使用糖皮质激素。1周后复查胸部CT,纵隔气肿均完全吸收,肺部病灶明显好转。结论COVID-19并发纵隔气肿者多为学龄前期或学龄期儿童,婴幼儿少见。可同时合并颈部及胸壁积气。肺部病变可累及间质或实质、双肺均受累,表现形式多样。起病多有明显气急,积极氧疗。白细胞计数明显升高,同时超敏C反应蛋白明显升高者,要密切关注呼吸情况,积极使用IVIG,适时适量应用糖皮质激素,必要时采用呼吸机人工辅助通气。 展开更多
关键词 新型冠状病毒感染 纵隔气肿 临床特征 体层摄影术 螺旋计算机 儿童
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基于北方寒地冻土的螺旋式挖坑机设计与试验
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作者 尹大庆 王雪 苏林峰 《农机化研究》 北大核心 2025年第1期157-164,172,共9页
针对目前市场上缺少适宜冻土环境作业挖坑机械的问题,以适用于北方寒地的螺旋式挖坑机为研究对象,通过测量哈尔滨的冻土参数并与硬质土壤进行对比,获得工作对象土壤参数。结合移栽白桦树苗所需穴坑尺寸,对挖坑机工作部件进行参数设计。... 针对目前市场上缺少适宜冻土环境作业挖坑机械的问题,以适用于北方寒地的螺旋式挖坑机为研究对象,通过测量哈尔滨的冻土参数并与硬质土壤进行对比,获得工作对象土壤参数。结合移栽白桦树苗所需穴坑尺寸,对挖坑机工作部件进行参数设计。根据运动学分析确定了升运土壤的临界转速,对挖坑机的工作参数进行分析,并得到了装置所需的功率。为便于开展试验验证,运用相似理论对试验装置和作业穴坑进行了等比例缩放,试验用钻头长度为400 mm,叶片长度为200 mm,钻尖半径为100 mm,转速大于155 r/min,动力源额定功率为4 kW。试验结果表明:当刀片组合方式为平刀-锯齿刀时,可以获得最短的挖坑时间。研究结果可为北方寒地秋冬季节冻土条件下,树苗移栽时螺旋式挖坑机的设计提供参考。 展开更多
关键词 挖坑机 螺旋式 冻土 钻头
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Design of Pinion Machine Tool-settings for Spiral Bevel Gears by Controlling Contact Path and Transmission Errors 被引量:12
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作者 曹雪梅 方宗德 +1 位作者 许浩 苏进展 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第2期179-186,共8页
This paper proposes a new approach to design pinion machine tool-settings for spiral bevel gears by controlling contact path and transmission errors. It is based on the satisfaction of contact condition of three given... This paper proposes a new approach to design pinion machine tool-settings for spiral bevel gears by controlling contact path and transmission errors. It is based on the satisfaction of contact condition of three given control points on the tooth surface. The three meshing points are controlled to be on a predesigned straight contact path that meets the pre-designed parabolic function of transmission errors. Designed separately, the magnitude of transmission errors and the orientation of the contact path are subjected to precise control. In addition, in order to meet the manufacturing requirements, we suggest to modify the values of blank offset, one of the pinion machine tool-settings, and redesign pinion ma- chine tool-settings to ensure that the magnitude and the geometry of transmission errors should not be influenced apart from minor effects on the predesigned straight contact path. The proposed approach together with its ideas has been proven by a numerical example and the manufacturing practice of a pair of spiral bevel gears. 展开更多
关键词 spiral bevel gear contact path transmission error blank offset tooth contact analysis
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EFFECT OF TOOL-PATH ON MILLING ACCURACY UNDER CLAMPING 被引量:5
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作者 郭魂 左敦稳 +2 位作者 王树宏 徐礼林 王珉 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第3期234-239,共6页
To resolve the deformation problem for thin-walled aero-parts in the actual production, this paper simulates the effect of the tool-path on the machining accuracy of the thin-walled frame. The frame is shaped in the p... To resolve the deformation problem for thin-walled aero-parts in the actual production, this paper simulates the effect of the tool-path on the machining accuracy of the thin-walled frame. The frame is shaped in the part milling under a given clamping condition by using the three-dimensional finite element method (FEM). Result shows that the sidewall deformation has a big difference if only the tool-path changes. When the tool-path from the outside to the inside is used, the machining deformation is smaller than another three kinds of toolpaths. Simulation results are compared with experimental data, and the correctness of the simulation is verified.Reasonable processing paths can be found by FEM. 展开更多
关键词 finite element method tool-path machining accuracy DEFORMATION
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Spiral刺绣针法的路径生成算法 被引量:4
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作者 田启明 罗予频 胡东成 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2006年第1期9-13,共5页
Spiral刺绣针法是一种重要的刺绣针法.首先将待刺绣的区域划分成若干能够生成连续螺旋线的环状子区域,然后将这些子区域组织成一个二叉树结构,采用一个递归过程来连接各个子区域内的螺旋线,最终形成Spiral针法路径.文中算法生成的路径... Spiral刺绣针法是一种重要的刺绣针法.首先将待刺绣的区域划分成若干能够生成连续螺旋线的环状子区域,然后将这些子区域组织成一个二叉树结构,采用一个递归过程来连接各个子区域内的螺旋线,最终形成Spiral针法路径.文中算法生成的路径能够由内向外以等距的螺旋线填充任意形状多边形的连通域,并且螺旋线的形状与区域的边界相似.实验结果表明,该算法能获得较好的刺绣效果. 展开更多
关键词 spiral针法 刺绣CAD 环切 形状分析
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Spiral MRI和图像处理 被引量:2
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作者 卢广 刘买利 叶朝辉 《波谱学杂志》 CAS CSCD 北大核心 2004年第2期175-183,共9页
介绍了在BrukerBiospec 47/30超导核磁共振成象仪 ( 4 .7T)上实现Spiral快速成像及图像处理系统 .图像处理系统基于PC技术构建而成 ,主要功能包括 :1 )将以Spiral形式采集到的时域磁共振信号转化为适用于快速傅立叶变换的笛卡尔网格 (Ca... 介绍了在BrukerBiospec 47/30超导核磁共振成象仪 ( 4 .7T)上实现Spiral快速成像及图像处理系统 .图像处理系统基于PC技术构建而成 ,主要功能包括 :1 )将以Spiral形式采集到的时域磁共振信号转化为适用于快速傅立叶变换的笛卡尔网格 (Cartesian)形式 (网格化处理 ) ;2 )二维快速傅立叶变换 ( 2D FFT ,图像重建 ) ;3)由化学位移偏置或磁场不均匀引起得偏共振效应 (off resonanceeffect)的校正 ;4)图像分析 .该软件适用于包括以多片多回波在内的各种采样方式得到的Spiral图像的重建和分析 ,也适用于常规成像数据的重建和分析 .所得到的图像可以以数据方式保存以供再次读入 ,也能够以TIF、GIF、JPG、BM等格式辅出为图像文件 . 展开更多
关键词 核磁共振成像 图像重建软件 快速傅立叶变换 笛卡尔网格 spiral
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Three-dimensional Imaging of Multi-slice Spiral CT in Bronchial Artery Correlative Study on Blood Supply of Central Lung Cancer and Its Clinical Significance 被引量:4
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作者 李智勇 杨冬 +2 位作者 伍建林 黎庶 董天 《The Chinese-German Journal of Clinical Oncology》 CAS 2005年第1期40-42,67,共4页
Objective: To evaluate three-dimensional bronchial artery imaging charactersin central lung cancer and applied values with multi-slice spiral CT (MSCT) to provide theoreticalevidence on blood supply and intervention t... Objective: To evaluate three-dimensional bronchial artery imaging charactersin central lung cancer and applied values with multi-slice spiral CT (MSCT) to provide theoreticalevidence on blood supply and intervention therapy. Methods: Eighteen patients with central lungcancer underwent MSCT with real time helical thin-slice CT scanning. Three-dimensional bronchialartery reconstruction was done at the console work-station. The space anatomical characters ofbronchial artery were observed through different rotations. Results: For 6 cases, thethree-dimensional images of bronchial artery (33.33%) could exactly show the origins, the routes(lung inner segment and mediatism segment) and the diameters of bronchial arteries. Vision rate ofbronchial arteries was the highest in pulmonary artery stricture and truncation groups, and thevessels' diameter became larger apparently. These characters demonstrated blood supply of this kindof central lung cancer come from bronchial artery. Volume rendering images were the best ones amongthree-dimensional images. Conclusion: Three-dimensional imaging with MSCT in bronchial artery canreveal the anatomical characters of bronchial artery and provide theoretical evidence on bloodsupply and intervention therapy of central lung cancer. 展开更多
关键词 bronchial artery multi-slice spiral CT three-dimensional reconstruction ANGIOGRAPHY
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Influence of spiral crystal selector on crystal orientation of single crystal superalloy 被引量:3
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作者 张如林 陈丽娜 +3 位作者 李重河 王宁 鲁雄刚 任忠鸣 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1092-1095,共4页
To increase efficiency and improve performance, reducing cost and emissions, advanced single crystal Ni-based superalloys are required in aerospace propulsion and power generating gas turbines. With the development of... To increase efficiency and improve performance, reducing cost and emissions, advanced single crystal Ni-based superalloys are required in aerospace propulsion and power generating gas turbines. With the development of alloy, significant improvements in casting techniques have been achieved by introducing the directionally solidified (DS) casting process followed by single crystal (SX) technique. The deviation of preferred orientation of single crystal superalloys is one of the most important defects in casting. In directional solidification equipment with high temperature gradient, single crystal specimens of DZ417G alloy were prepared successfully by the modified Bridgeman method with spiral grain selector. The orientation was investigated by means of X-ray diffraction (XRD) and electron backscattered diffraction (EBSD).The results show that the crystal selector with a smaller angle can effectively reduce the deviation of preferred orientation. 展开更多
关键词 nickel-base superalloy directional solidification single crystal superalloy crystal orientation spiral grain selector
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