With the growing needs of prepreg tapes for the automated fiber placement(AFP),the deviation-rectifying of prepreg in slitting process was investigated on a self-developed 16-tow prepreg slitting and winding machine.T...With the growing needs of prepreg tapes for the automated fiber placement(AFP),the deviation-rectifying of prepreg in slitting process was investigated on a self-developed 16-tow prepreg slitting and winding machine.The process of slitting and rewinding of prepreg tape was introduced,and the reason of prepreg tape deviation in slitting process was analyzed.In order to ensure the quality of the narrow prepreg slits,the application of the fuzzy PID algorithm in a closed-loop control system was discussed.A fuzzy PID algorithm was designed by combining fuzzy rules and PID controller.By applying it to precise deviation-rectifying control strategy,the automatic control of rectification could be achieved with accuracy of 0.1 mm,which satisfies the requirement of the prepreg tape both in slitting quality and layup quality for AFP.展开更多
背景:轴突导向因子可能在α-突触核蛋白相关神经退行性疾病中发挥重要作用。目的:探讨轴突导向因子在α-突触核蛋白相关神经退行性疾病中的作用及机制。方法:由第一作者系统检索中国知网、万方数据库、PubMed、Nature、Embase、Web of S...背景:轴突导向因子可能在α-突触核蛋白相关神经退行性疾病中发挥重要作用。目的:探讨轴突导向因子在α-突触核蛋白相关神经退行性疾病中的作用及机制。方法:由第一作者系统检索中国知网、万方数据库、PubMed、Nature、Embase、Web of Sciense、JAMA、BMJ等数据库,中文检索词为“帕金森病,轴突导向因子,路易体痴呆,多系统衰竭,单纯性自主神经功能衰竭”,英文检索词为“Parkinson’s disease,axon guidance molecules,Netrin,Ephrin,Semaphorin,Slit,Dementia with Lewy Bodies,Multiple System Atrophy,Pure Autonomic Failure”,全面收集并整理近年来有关轴突导向因子与α-突触核蛋白相关神经退行性疾病的文献,最终纳入89篇文献进行综述分析。结果与结论:轴突导向因子蛋白家族包括Netrins、Ephrins、Semaphorins和Slits。Netrins通过影响肠道因子、依赖DCC受体调节多巴胺能神经元活力,进而影响神经退行性疾病进程。在Ephrins家族中,EphrinA/EphA参与介导神经元再生信号,EphA1借CXC趋化因子配体12/CXC趋化因子受体4通路调节炎症与神经病理,影响疾病发展。Semaphorins家族中的Semaphorins-3通过引导多巴胺能神经元轴突从黑质向纹状体生长,进而改善神经退行性疾病的行为学症状。在多巴胺能神经元轴突传导通路上,Slits经Slit/Robo等信号协作调控轴突定位与寻路过程,确保神经元信号传导路径的准确性,对神经元连接的维持与修复具有重要意义。展开更多
Deep mining of natural resources,like coal,is increasingly utilizing directional blasting technology with slit charge for rock blasting at greater depths.This study,based on numerical simulation methods,analyzes the d...Deep mining of natural resources,like coal,is increasingly utilizing directional blasting technology with slit charge for rock blasting at greater depths.This study,based on numerical simulation methods,analyzes the dynamic behavior of slit charge blasting in three aspects:slit tube dynamic response,hoop stress evolution,and crack propagation.According to research findings,the failure mode of the slit tube mainly manifests as a tensile fracture of the inner wall and a shear fracture at the end connection,where the end connection of the slit tube is the weak point of the overall structure.The dynamic response of the slit tube mainly exhibits radial response in the vertical direction of the slit and hoop response in the slit direction.The hoop tensile stress plays a crucial role in determining the spread of cracks caused by explosions.As the in situ stress increases,the peak hoop tensile stress reduces,and the peak hoop compressive stress increases.This hinders the propagation of cracks.In addition,the directional impact is most pronounced in the middle of the borehole,with the longest primary directional crack observed.Conversely,the directional impact is least favorable near the bottom of the borehole.When the in situ stress reaches 60MPa,the purpose of directional fracture has not been achieved,suggesting combining presplit blasting for in situ stress relief to improve rock breaking efficiency.展开更多
During aging,the spine undergoes degenerative changes,particularly with vertebral endplate bone expansion and sclerosis,that are associated with nonspecific low back pain.We report that parathyroid hormone(PTH)treatme...During aging,the spine undergoes degenerative changes,particularly with vertebral endplate bone expansion and sclerosis,that are associated with nonspecific low back pain.We report that parathyroid hormone(PTH)treatment reduced vertebral endplate sclerosis and improved pain behaviors in three mouse models of spinal degeneration(aged,SM/J,and young lumbar spine instability mice).Aberrant innervation in the vertebral body and endplate during spinal degeneration was decreased with PTH treatment as quantified by PGP9.5^(+)and CGRP^(+)nerve fibers,as well as CGRP expression in dorsal root ganglia.The neuronal repulsion factor Slit3 significantly increased in response to PTH treatment mediated by transcriptional factor FoxA2.PTH type 1 receptor and Slit3 deletion in osteocalcin-expressing cells prevented PTH-reduction of endplate porosity and improvement in behavior tests.Altogether,PTH stimulated osteoblast production of Slit3,decreased aberrant sensory nerve innervation,and provided symptomatic relief of LBP associated with mouse spinal degeneration.展开更多
We demonstrate a high-speed rotating slit beam shaping method for femtosecond(fs)laser three-dimensional(3D)isotropic inscription in glass materials.By integrating fs laser direct writing with a real-time rotating sli...We demonstrate a high-speed rotating slit beam shaping method for femtosecond(fs)laser three-dimensional(3D)isotropic inscription in glass materials.By integrating fs laser direct writing with a real-time rotating slit mechanism,a 3D symmetric spherical focal field distribution is created in the laser-irradiated regions of transparent substrates.The corresponding focal field distribution is theoretically calculated and validated by examining the features of laser-inscribed lines in glass samples.Moreover,we investigate the influences of laser writing speed and slit rotational speed on the fabrication resolution in glass,and discuss the formation mechanism of the generated periodic microstructures.To showcase its powerful capability for3D isotropic fabrication,the high-speed rotating slit beam shaping method is applied to create straight optical waveguides,bending optical waveguides,and hollow microchannels in the glass.The proposed method holds great potential for the facile manufacture of diverse 3D isotropic microstructures and devices within transparent materials across various applications,including advanced photonics,microoptics,micro-electromechanical systems,and microfluidics.展开更多
Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance protei...Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.展开更多
Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rat...Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rate among invertebrates. This biological phenomenon contrasts sharply with engineered systems, which generally associates high accuracy with substantial energy consumption. Inspired by the Scorpion Compound Slit Sensilla (SCSS) with a stress field modulation strategy, a bionic positioning sensor with superior precision and minimal power consumption is developed for the first time, which utilizes the particular Minimum Positioning Units (MPUs) to efficiently locate vibration signals. The single MPU of the SCSS can recognize the direction of collinear loads by regulating the stress field distribution and further, the coupling action of three MPUs can realize all-angle vibration monitoring in plane. Experiments demonstrate that the bionic positioning sensor achieves 1.43 degrees of angle-error-free accuracy without additional energy supply. As a proof of concept, two bionic positioning sensors and machine learning algorithm are integrated to provide centimeter (cm)-accuracy target localization, ideally suited for the man-machine interaction. The novel design offers a new mechanism for the design of traditional positioning devices, improving precision and efficiency in both the meta-universe and real-world Internet-connected systems.展开更多
目的:探讨电针对大鼠坐骨神经损伤后神经导向因子Slit1及其mRNA表达的影响。方法:将72只SD大鼠按随机数字表法分为正常组、模型组和治疗组,每组各24只。建立大鼠右坐骨神经横断后即刻端对端缝合模型。治疗组取"环跳"、"...目的:探讨电针对大鼠坐骨神经损伤后神经导向因子Slit1及其mRNA表达的影响。方法:将72只SD大鼠按随机数字表法分为正常组、模型组和治疗组,每组各24只。建立大鼠右坐骨神经横断后即刻端对端缝合模型。治疗组取"环跳"、"足三里"电针治疗,每日1次,7 d 1个疗程,连续3个疗程。每个疗程结束后以免疫组化法、RT-PCR法分别检测坐骨神经和相应脊髓段(L4-L6)Slit1及其mRNA的表达变化。结果:治疗组Slit1及其mRNA在第1疗程后达到高峰之后逐渐降低,显著高于模型组(P<0.01),且治疗组与模型组始终都显著高于正常组(P<0.01)。结论:电针治疗能明显增强损伤坐骨神经和相应脊髓段(L4-L6)中Slit1及其mRNA的表达,促进周围神经损伤再生修复。展开更多
基金financially supported by the National Basic Research Program of China(973Program)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Fundamental Research Funds for the Central Universities ( No. 3082615NS2015056)
文摘With the growing needs of prepreg tapes for the automated fiber placement(AFP),the deviation-rectifying of prepreg in slitting process was investigated on a self-developed 16-tow prepreg slitting and winding machine.The process of slitting and rewinding of prepreg tape was introduced,and the reason of prepreg tape deviation in slitting process was analyzed.In order to ensure the quality of the narrow prepreg slits,the application of the fuzzy PID algorithm in a closed-loop control system was discussed.A fuzzy PID algorithm was designed by combining fuzzy rules and PID controller.By applying it to precise deviation-rectifying control strategy,the automatic control of rectification could be achieved with accuracy of 0.1 mm,which satisfies the requirement of the prepreg tape both in slitting quality and layup quality for AFP.
文摘背景:轴突导向因子可能在α-突触核蛋白相关神经退行性疾病中发挥重要作用。目的:探讨轴突导向因子在α-突触核蛋白相关神经退行性疾病中的作用及机制。方法:由第一作者系统检索中国知网、万方数据库、PubMed、Nature、Embase、Web of Sciense、JAMA、BMJ等数据库,中文检索词为“帕金森病,轴突导向因子,路易体痴呆,多系统衰竭,单纯性自主神经功能衰竭”,英文检索词为“Parkinson’s disease,axon guidance molecules,Netrin,Ephrin,Semaphorin,Slit,Dementia with Lewy Bodies,Multiple System Atrophy,Pure Autonomic Failure”,全面收集并整理近年来有关轴突导向因子与α-突触核蛋白相关神经退行性疾病的文献,最终纳入89篇文献进行综述分析。结果与结论:轴突导向因子蛋白家族包括Netrins、Ephrins、Semaphorins和Slits。Netrins通过影响肠道因子、依赖DCC受体调节多巴胺能神经元活力,进而影响神经退行性疾病进程。在Ephrins家族中,EphrinA/EphA参与介导神经元再生信号,EphA1借CXC趋化因子配体12/CXC趋化因子受体4通路调节炎症与神经病理,影响疾病发展。Semaphorins家族中的Semaphorins-3通过引导多巴胺能神经元轴突从黑质向纹状体生长,进而改善神经退行性疾病的行为学症状。在多巴胺能神经元轴突传导通路上,Slits经Slit/Robo等信号协作调控轴突定位与寻路过程,确保神经元信号传导路径的准确性,对神经元连接的维持与修复具有重要意义。
基金National Natural Science Foundation of China,Grant/Award Numbers:52204085,52227805。
文摘Deep mining of natural resources,like coal,is increasingly utilizing directional blasting technology with slit charge for rock blasting at greater depths.This study,based on numerical simulation methods,analyzes the dynamic behavior of slit charge blasting in three aspects:slit tube dynamic response,hoop stress evolution,and crack propagation.According to research findings,the failure mode of the slit tube mainly manifests as a tensile fracture of the inner wall and a shear fracture at the end connection,where the end connection of the slit tube is the weak point of the overall structure.The dynamic response of the slit tube mainly exhibits radial response in the vertical direction of the slit and hoop response in the slit direction.The hoop tensile stress plays a crucial role in determining the spread of cracks caused by explosions.As the in situ stress increases,the peak hoop tensile stress reduces,and the peak hoop compressive stress increases.This hinders the propagation of cracks.In addition,the directional impact is most pronounced in the middle of the borehole,with the longest primary directional crack observed.Conversely,the directional impact is least favorable near the bottom of the borehole.When the in situ stress reaches 60MPa,the purpose of directional fracture has not been achieved,suggesting combining presplit blasting for in situ stress relief to improve rock breaking efficiency.
基金supported by the U.S.Department of Health&Human Services NIH National Institute on Aging under Award Number P01AG066603(to J.C.)。
文摘During aging,the spine undergoes degenerative changes,particularly with vertebral endplate bone expansion and sclerosis,that are associated with nonspecific low back pain.We report that parathyroid hormone(PTH)treatment reduced vertebral endplate sclerosis and improved pain behaviors in three mouse models of spinal degeneration(aged,SM/J,and young lumbar spine instability mice).Aberrant innervation in the vertebral body and endplate during spinal degeneration was decreased with PTH treatment as quantified by PGP9.5^(+)and CGRP^(+)nerve fibers,as well as CGRP expression in dorsal root ganglia.The neuronal repulsion factor Slit3 significantly increased in response to PTH treatment mediated by transcriptional factor FoxA2.PTH type 1 receptor and Slit3 deletion in osteocalcin-expressing cells prevented PTH-reduction of endplate porosity and improvement in behavior tests.Altogether,PTH stimulated osteoblast production of Slit3,decreased aberrant sensory nerve innervation,and provided symptomatic relief of LBP associated with mouse spinal degeneration.
基金supported by the National Key Research and Development Program of China(2022YFA1404800)National Natural Science Foundation of China(12174107,12004221,12192254,92250304,W2441005,12334014,12192251)+4 种基金Natural Science Foundation of Shandong Province(ZR2024QA024,ZR2021ZD02)Postdoctoral Innovation Talents Support Program of Shandong Province(No.SDBX2019005)Shanghai Municipal Science and Technology Major ProjectFundamental Research Funds for the Central UniversitiesEngineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(No.2023nmc005)。
文摘We demonstrate a high-speed rotating slit beam shaping method for femtosecond(fs)laser three-dimensional(3D)isotropic inscription in glass materials.By integrating fs laser direct writing with a real-time rotating slit mechanism,a 3D symmetric spherical focal field distribution is created in the laser-irradiated regions of transparent substrates.The corresponding focal field distribution is theoretically calculated and validated by examining the features of laser-inscribed lines in glass samples.Moreover,we investigate the influences of laser writing speed and slit rotational speed on the fabrication resolution in glass,and discuss the formation mechanism of the generated periodic microstructures.To showcase its powerful capability for3D isotropic fabrication,the high-speed rotating slit beam shaping method is applied to create straight optical waveguides,bending optical waveguides,and hollow microchannels in the glass.The proposed method holds great potential for the facile manufacture of diverse 3D isotropic microstructures and devices within transparent materials across various applications,including advanced photonics,microoptics,micro-electromechanical systems,and microfluidics.
基金supported by Shenzhen University General Hospital Scientific Research Project,No.SUGH2019QD002Shenzhen Science and Technology Development Foundation,No.20220810173216001(both to ZS).
文摘Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.
基金supported by the National Natural Science Foundation of China(No.52175269)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)+2 种基金Science and Technology Research Project of Education Department of Jilin Province(JJKH20231146KJ,JJKH20241262KJ)Project ZR2024ME104 supported by Shandong Provincial Natural Science FoundationChina Postdoctoral Science Foundation(No.2024M751086).
文摘Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rate among invertebrates. This biological phenomenon contrasts sharply with engineered systems, which generally associates high accuracy with substantial energy consumption. Inspired by the Scorpion Compound Slit Sensilla (SCSS) with a stress field modulation strategy, a bionic positioning sensor with superior precision and minimal power consumption is developed for the first time, which utilizes the particular Minimum Positioning Units (MPUs) to efficiently locate vibration signals. The single MPU of the SCSS can recognize the direction of collinear loads by regulating the stress field distribution and further, the coupling action of three MPUs can realize all-angle vibration monitoring in plane. Experiments demonstrate that the bionic positioning sensor achieves 1.43 degrees of angle-error-free accuracy without additional energy supply. As a proof of concept, two bionic positioning sensors and machine learning algorithm are integrated to provide centimeter (cm)-accuracy target localization, ideally suited for the man-machine interaction. The novel design offers a new mechanism for the design of traditional positioning devices, improving precision and efficiency in both the meta-universe and real-world Internet-connected systems.
文摘目的:探讨电针对大鼠坐骨神经损伤后神经导向因子Slit1及其mRNA表达的影响。方法:将72只SD大鼠按随机数字表法分为正常组、模型组和治疗组,每组各24只。建立大鼠右坐骨神经横断后即刻端对端缝合模型。治疗组取"环跳"、"足三里"电针治疗,每日1次,7 d 1个疗程,连续3个疗程。每个疗程结束后以免疫组化法、RT-PCR法分别检测坐骨神经和相应脊髓段(L4-L6)Slit1及其mRNA的表达变化。结果:治疗组Slit1及其mRNA在第1疗程后达到高峰之后逐渐降低,显著高于模型组(P<0.01),且治疗组与模型组始终都显著高于正常组(P<0.01)。结论:电针治疗能明显增强损伤坐骨神经和相应脊髓段(L4-L6)中Slit1及其mRNA的表达,促进周围神经损伤再生修复。
基金supported by the National Basic Research Development Program(973)of China(No.2012CB114603)Special Fund of Shandong Province for High Level Overseas TalentsChina(No.72019)
