The Slit family of axon guidance cues act as repulsive molecules for precise axon pathfinding and neuronal migration during nervous system development through interactions with specific Robo receptors.Although we prev...The Slit family of axon guidance cues act as repulsive molecules for precise axon pathfinding and neuronal migration during nervous system development through interactions with specific Robo receptors.Although we previously reported that Slit1–3 and their receptors Robo1 and Robo2 are highly expressed in the adult mouse peripheral nervous system,how this expression changes after injury has not been well studied.Herein,we constructed a peripheral nerve injury mouse model by transecting the right sciatic nerve.At 14 days after injury,quantitative real-time polymerase chain reaction was used to detect mRNA expression of Slit1–3 and Robo1–2 in L4–5 spinal cord and dorsal root ganglia,as well as the sciatic nerve.Immunohistochemical analysis was performed to examine Slit1–3,Robo1–2,neurofilament heavy chain,F4/80,and vimentin in L4–5 spinal cord,L4 dorsal root ganglia,and the sciatic nerve.Co-expression of Slit1–3 and Robo1–2 in L4 dorsal root ganglia was detected by in situ hybridization.In addition,Slit1–3 and Robo1–2 protein expression in L4–5 spinal cord,L4 dorsal root ganglia,and sciatic nerve were detected by western blot assay.The results showed no significant changes of Slit1–3 or Robo1–2 mRNA expression in the spinal cord within 14 days after injury.In the dorsal root ganglion,Slit1–3 and Robo1–2 mRNA expression were initially downregulated within 4 days after injury;however,Robo1–2 mRNA expression returned to the control level,while Slit1–3 mRNA expression remained upregulated during regeneration from 4–14 days after injury.In the sciatic nerve,Slit1–3 and their receptors Robo1–2 were all expressed in the proximal nerve stump;however,Slit1,Slit2,and Robo2 were barely detectable in the nerve bridge and distal nerve stump within 14 days after injury.Slit3 was highly ex-pressed in macrophages surrounding the nerve bridge and slightly downregulated in the distal nerve stump within 14 days after injury.Robo1 was upregulated in vimentin-positive cells and migrating Schwann cells inside the nerve bridge.Robo1 was also upregulated in Schwann cells of the distal nerve stump within 14 days after injury.Our findings indicate that Slit3 is the major ligand expressed in the nerve bridge and distal nerve stump during peripheral nerve regeneration,and Slit3/Robo signaling could play a key role in peripheral nerve repair after injury.This study was approved by Plymouth University Animal Welfare Ethical Review Board (approval No.30/3203) on April 12,2014.展开更多
Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and ...Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and floor was considered. Experiments and simulations were performed to investigate the flow and diffusion fields that are affected by this floor level slit exhaust ventilation system. The characteristics of airflow with experiments and computation fluid dynamics （CFD） are generally similar except airflow at the location of impinging flow and the location right below the inlet. Riboflavin particles were used as the house dust. For the spatial distribution of riboflavin particles in the ventilation system before operation, due to the influence of gravity, different sizes of particles show smooth decay curve. After floor level slit exhaust ventilation system is operated, the decay rate of the particles becomes faster than that after the ventilation system is powered on, and the particles with diameter of 0.5-3.0 μm in the experimental data and calculated values show good agreement.展开更多
A non-reacting system and a reacting system are run with an on-line slit rheometer devel-oped by the authors.It is found that the polyurethane-urea system behaves slightly elastic and theZaremba-Fromm-Dewitt model may...A non-reacting system and a reacting system are run with an on-line slit rheometer devel-oped by the authors.It is found that the polyurethane-urea system behaves slightly elastic and theZaremba-Fromm-Dewitt model may be employed to describe its rheological behaviors.After the geltime,the inside pressure of the testing materials varies dramatically.Reports in this respect have notbeen found in literature,as yet its mechanism warrants further studies.展开更多
In this work, a portable slit imaging system is developed to study both the electron beam diameter and the profile of the newly developed Shanghai Electron Beam Ion Trap （Shanghai EBIT）. Images are detected by a cha...In this work, a portable slit imaging system is developed to study both the electron beam diameter and the profile of the newly developed Shanghai Electron Beam Ion Trap （Shanghai EBIT）. Images are detected by a charge coupled device （CCD） sensitive to both X rays and longer wavelength photons （up to visible）. Large scale ray tracings were conducted for correcting the image broadening effects caused by the finite slit width and the finite width of the CCD pixels. A numerical de-convolution method was developed to analyse and reconstruct the electron beam density distribution in the EBIT. As an example of the measured beam diameter and current density, the FWHM （full width at half maximum） diameter of the electron beam at 81 keV and 120 mA is found to be 76.2 μm and the density 2.00 × 10^3 A.cm-2, under a magnetic field of 3 T, including all corrections.展开更多
Chinese physicists are sealing the UN International Year of Quantum Science and Technology(IYQ)with an experiment to help close the classic debate between Albert Einstein and Niels Bohr on quantum uncertainty.To rebut...Chinese physicists are sealing the UN International Year of Quantum Science and Technology(IYQ)with an experiment to help close the classic debate between Albert Einstein and Niels Bohr on quantum uncertainty.To rebut Bohr,Einstein designed a Gedankenexperiment(thought experiment in German),a revised double-slit interference experiment.His design,however,is so challenging to realize that it remained a thought experiment for a long time.Now Profs.CHEN Mingcheng,LU Chaoyang,PAN Jianwei from the University of Science and Technology of China(USTC)and their colleagues built an innovative setup to directly replicate Einstein’s idea-demonstrating that he was wrong.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
Slit2/Robo1 is a conserved ligand-receptor system,which greatly affects the distribution,migration,axon guidance and branching of neuron cells.Slit2 and its transmembrane receptor Robo1 have different distribution pat...Slit2/Robo1 is a conserved ligand-receptor system,which greatly affects the distribution,migration,axon guidance and branching of neuron cells.Slit2 and its transmembrane receptor Robo1 have different distribution patterns in gliomas.The expression of Slit2 is at very low levels in pilocytic astrocytoma,fibrillary astrocytoma and glioblastoma,while Robo1 is highly expressed in different grades of gliomas at both mRNA and protein levels.Acquisition of insidious invasiveness by malignant glioma cells involves multiple genetic alterations in signaling pathways.Although the specific mechanisms of tumor-suppressive effect of Slit2/Robo1 have not been elucidated,it has been proved that Slit2/Robo1 signaling inhibits glioma cellmigration and invasion by inactivation of Cdc42-GTP.With the research development on the molecular mechanisms of Slit2/Robo1 signaling in glioma invasion and migration,Slit2/Robo1 signaling may become a potential target for glioma prevention and treatment.展开更多
基金supported by the National Natural Science Foundation of China,No.81371353(to XPD)
文摘The Slit family of axon guidance cues act as repulsive molecules for precise axon pathfinding and neuronal migration during nervous system development through interactions with specific Robo receptors.Although we previously reported that Slit1–3 and their receptors Robo1 and Robo2 are highly expressed in the adult mouse peripheral nervous system,how this expression changes after injury has not been well studied.Herein,we constructed a peripheral nerve injury mouse model by transecting the right sciatic nerve.At 14 days after injury,quantitative real-time polymerase chain reaction was used to detect mRNA expression of Slit1–3 and Robo1–2 in L4–5 spinal cord and dorsal root ganglia,as well as the sciatic nerve.Immunohistochemical analysis was performed to examine Slit1–3,Robo1–2,neurofilament heavy chain,F4/80,and vimentin in L4–5 spinal cord,L4 dorsal root ganglia,and the sciatic nerve.Co-expression of Slit1–3 and Robo1–2 in L4 dorsal root ganglia was detected by in situ hybridization.In addition,Slit1–3 and Robo1–2 protein expression in L4–5 spinal cord,L4 dorsal root ganglia,and sciatic nerve were detected by western blot assay.The results showed no significant changes of Slit1–3 or Robo1–2 mRNA expression in the spinal cord within 14 days after injury.In the dorsal root ganglion,Slit1–3 and Robo1–2 mRNA expression were initially downregulated within 4 days after injury;however,Robo1–2 mRNA expression returned to the control level,while Slit1–3 mRNA expression remained upregulated during regeneration from 4–14 days after injury.In the sciatic nerve,Slit1–3 and their receptors Robo1–2 were all expressed in the proximal nerve stump;however,Slit1,Slit2,and Robo2 were barely detectable in the nerve bridge and distal nerve stump within 14 days after injury.Slit3 was highly ex-pressed in macrophages surrounding the nerve bridge and slightly downregulated in the distal nerve stump within 14 days after injury.Robo1 was upregulated in vimentin-positive cells and migrating Schwann cells inside the nerve bridge.Robo1 was also upregulated in Schwann cells of the distal nerve stump within 14 days after injury.Our findings indicate that Slit3 is the major ligand expressed in the nerve bridge and distal nerve stump during peripheral nerve regeneration,and Slit3/Robo signaling could play a key role in peripheral nerve repair after injury.This study was approved by Plymouth University Animal Welfare Ethical Review Board (approval No.30/3203) on April 12,2014.
基金Project supported by Ministry of Land, Infrastructure, Transport and Tourism of Japan Project(DUT10RC(3)103) supported by the Fundamental Research Funds for the Central Universities in China+2 种基金 Project(20111027) supported by the Liaoning Provincial Scientific Research Foundation, China Key Project (2012BAJ02B05) supported by the Twelfth Five-Year National Technology Program of China Project supported by Dalian Municipal Construction Technology Program, China
文摘Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and floor was considered. Experiments and simulations were performed to investigate the flow and diffusion fields that are affected by this floor level slit exhaust ventilation system. The characteristics of airflow with experiments and computation fluid dynamics （CFD） are generally similar except airflow at the location of impinging flow and the location right below the inlet. Riboflavin particles were used as the house dust. For the spatial distribution of riboflavin particles in the ventilation system before operation, due to the influence of gravity, different sizes of particles show smooth decay curve. After floor level slit exhaust ventilation system is operated, the decay rate of the particles becomes faster than that after the ventilation system is powered on, and the particles with diameter of 0.5-3.0 μm in the experimental data and calculated values show good agreement.
基金Supported by the National Natural Science Foundation of China.
文摘A non-reacting system and a reacting system are run with an on-line slit rheometer devel-oped by the authors.It is found that the polyurethane-urea system behaves slightly elastic and theZaremba-Fromm-Dewitt model may be employed to describe its rheological behaviors.After the geltime,the inside pressure of the testing materials varies dramatically.Reports in this respect have notbeen found in literature,as yet its mechanism warrants further studies.
基金Project supported by the National Natural Science Foundation of China （Grant No. 11074049）, the Chinese National Fusion Project for ITER （Grant No. 2009GB106001）, and the Shanghai Leading Academic Discipline Project, China （Grant No. B107）.
文摘In this work, a portable slit imaging system is developed to study both the electron beam diameter and the profile of the newly developed Shanghai Electron Beam Ion Trap （Shanghai EBIT）. Images are detected by a charge coupled device （CCD） sensitive to both X rays and longer wavelength photons （up to visible）. Large scale ray tracings were conducted for correcting the image broadening effects caused by the finite slit width and the finite width of the CCD pixels. A numerical de-convolution method was developed to analyse and reconstruct the electron beam density distribution in the EBIT. As an example of the measured beam diameter and current density, the FWHM （full width at half maximum） diameter of the electron beam at 81 keV and 120 mA is found to be 76.2 μm and the density 2.00 × 10^3 A.cm-2, under a magnetic field of 3 T, including all corrections.
文摘Chinese physicists are sealing the UN International Year of Quantum Science and Technology(IYQ)with an experiment to help close the classic debate between Albert Einstein and Niels Bohr on quantum uncertainty.To rebut Bohr,Einstein designed a Gedankenexperiment(thought experiment in German),a revised double-slit interference experiment.His design,however,is so challenging to realize that it remained a thought experiment for a long time.Now Profs.CHEN Mingcheng,LU Chaoyang,PAN Jianwei from the University of Science and Technology of China(USTC)and their colleagues built an innovative setup to directly replicate Einstein’s idea-demonstrating that he was wrong.
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)
基金supported by the grants of National Natural Science Foundation of China(No.30700253,30800355)the Program for Changjiang Scholars and Innovative Research Team in University,Ministry of Education,China(No.IRT0734)
文摘Slit2/Robo1 is a conserved ligand-receptor system,which greatly affects the distribution,migration,axon guidance and branching of neuron cells.Slit2 and its transmembrane receptor Robo1 have different distribution patterns in gliomas.The expression of Slit2 is at very low levels in pilocytic astrocytoma,fibrillary astrocytoma and glioblastoma,while Robo1 is highly expressed in different grades of gliomas at both mRNA and protein levels.Acquisition of insidious invasiveness by malignant glioma cells involves multiple genetic alterations in signaling pathways.Although the specific mechanisms of tumor-suppressive effect of Slit2/Robo1 have not been elucidated,it has been proved that Slit2/Robo1 signaling inhibits glioma cellmigration and invasion by inactivation of Cdc42-GTP.With the research development on the molecular mechanisms of Slit2/Robo1 signaling in glioma invasion and migration,Slit2/Robo1 signaling may become a potential target for glioma prevention and treatment.
