目的探讨烙灸治疗早期激素性股骨头坏死(steroid-induced osteonecrosis of the femoral head,SONFH)的作用机制。方法将新西兰兔按随机数表法分为空白组、模型组、烙灸组、抑制剂组,每组6只,采用内毒素联合激素的方法制备SONFH模型。...目的探讨烙灸治疗早期激素性股骨头坏死(steroid-induced osteonecrosis of the femoral head,SONFH)的作用机制。方法将新西兰兔按随机数表法分为空白组、模型组、烙灸组、抑制剂组,每组6只,采用内毒素联合激素的方法制备SONFH模型。烙灸组进行4周的烙灸治疗,抑制剂组给予IκBα磷酸化抑制剂Bay11-7082(1 mg·kg-1)腹腔注射3周。干预前后分别观察实验兔一般状况变化;HE染色观察各组实验兔股骨头组织病理学变化;Western blot和RT-qPCR分别检测股骨头组织中IKKβ、磷酸化IκBα(p-IκBα)蛋白及mRNA的表达变化;ELISA检测血清中核因子κB(nuclear factor kappa-B,NF-κB)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-6(interleukin-6,IL-6)水平。结果与空白组比较,模型组实验兔逐渐出现精神萎靡、毛发暗淡等情况,股骨头组织骨小梁出现断裂、稀疏等改变,IKKβ、p-IκBα蛋白水平,IKKβmRNA水平及血清中NF-κB、TNF-α、IL-6水平均升高(P均<0.05);与模型组比较,烙灸组股骨头组织病理学改善,IKKβ、p-IκBα蛋白水平,IKKβmRNA水平及血清中NF-κB、TNF-α、IL-6水平均降低(P均<0.05),而IκBα蛋白及mRNA表达均升高(P均<0.05)。结论烙灸可改善早期SONFH骨代谢,缓解骨坏死,其机制与抑制TLR4/NF-κB通路有关。展开更多
Magnesium(Mg)alloys have shown great prospects as both structural and biomedical materials,while poor corrosion resistance limits their further application.In this work,to avoid the time-consuming and laborious experi...Magnesium(Mg)alloys have shown great prospects as both structural and biomedical materials,while poor corrosion resistance limits their further application.In this work,to avoid the time-consuming and laborious experiment trial,a high-throughput computational strategy based on first-principles calculations is designed for screening corrosion-resistant binary Mg alloy with intermetallics,from both the thermodynamic and kinetic perspectives.The stable binary Mg intermetallics with low equilibrium potential difference with respect to the Mg matrix are firstly identified.Then,the hydrogen adsorption energies on the surfaces of these Mg intermetallics are calculated,and the corrosion exchange current density is further calculated by a hydrogen evolution reaction(HER)kinetic model.Several intermetallics,e.g.Y_(3)Mg,Y_(2)Mg and La_(5)Mg,are identified to be promising intermetallics which might effectively hinder the cathodic HER.Furthermore,machine learning(ML)models are developed to predict Mg intermetallics with proper hydrogen adsorption energy employing work function(W_(f))and weighted first ionization energy(WFIE).The generalization of the ML models is tested on five new binary Mg intermetallics with the average root mean square error(RMSE)of 0.11 eV.This study not only predicts some promising binary Mg intermetallics which may suppress the galvanic corrosion,but also provides a high-throughput screening strategy and ML models for the design of corrosion-resistant alloy,which can be extended to ternary Mg alloys or other alloy systems.展开更多
Bipolar junction transistors(BJTs) are often used in spacecraft due to their excellent working characteristics. However,the complex space radiation environment induces primary knock-on atoms(PKAs) in BJTs through coll...Bipolar junction transistors(BJTs) are often used in spacecraft due to their excellent working characteristics. However,the complex space radiation environment induces primary knock-on atoms(PKAs) in BJTs through collisions, resulting in hard-to-recover displacement damage and affecting the performance of electronic components. In this paper, the properties of PKAs induced by typical space heavy ions(C, N, O, Fe) in BJTs are investigated using Monte Carlo simulations. The simulated results show that the energy spectrum of ion-induced PKAs is primarily concentrated in the low-energy range(17eV–100eV) and displays similar features across all tested ions. The PKAs induced by the collision of energetic ions have large forward scattering angles, mainly around 88°. Moreover, the distribution of PKAs within a transistor as a function of depth displays a peak characteristic, and the peak position is linearly proportional to the incident energy at a certain energy range. These simulation outcomes serve as crucial theoretical support for long-term semiconductor material defect evolution and ground testing of semiconductor devices.展开更多
A dynamic multi-beam resource allocation algorithm for large low Earth orbit(LEO)constellation based on on-board distributed computing is proposed in this paper.The allocation is a combinatorial optimization process u...A dynamic multi-beam resource allocation algorithm for large low Earth orbit(LEO)constellation based on on-board distributed computing is proposed in this paper.The allocation is a combinatorial optimization process under a series of complex constraints,which is important for enhancing the matching between resources and requirements.A complex algorithm is not available because that the LEO on-board resources is limi-ted.The proposed genetic algorithm(GA)based on two-dimen-sional individual model and uncorrelated single paternal inheri-tance method is designed to support distributed computation to enhance the feasibility of on-board application.A distributed system composed of eight embedded devices is built to verify the algorithm.A typical scenario is built in the system to evalu-ate the resource allocation process,algorithm mathematical model,trigger strategy,and distributed computation architec-ture.According to the simulation and measurement results,the proposed algorithm can provide an allocation result for more than 1500 tasks in 14 s and the success rate is more than 91%in a typical scene.The response time is decreased by 40%com-pared with the conditional GA.展开更多
Objective:Circular RNAs(circRNAs)have been shown to involve in pathological processes of ischemic stroke(IS),including autophagy.This study was designed to explore the effect of circR-ZC3HC1 on neuronal autophagy in I...Objective:Circular RNAs(circRNAs)have been shown to involve in pathological processes of ischemic stroke(IS),including autophagy.This study was designed to explore the effect of circR-ZC3HC1 on neuronal autophagy in IS and the related mechanisms.Methods:Expression of circR-ZC3HC1 in blood samples of IS patients and healthy controls was detected.Hippocampal neurons were treated with oxygen and glucose deprivation(OGD)to establish IS in vitro model.The expression of LC3 and p62 and the number of autophagosomes were examined to evaluate the autophagy level of OGD induced neurons using western blotting and transmission electron microscope.Cell apoptosis rate and the expression of cleaved caspase-3,Bax,and Bcl-2 were assessed byflow cytometry and western blotting.The binding relationships among circR-ZC3HC1,miR-384-5p,and SIRT1 were predicted and verified.Results:Low expression of circR-ZC3HC1 was found in blood samples of IS patients and OGD-treated neurons.Overexpressed circR-ZC3HC1 or inhibited miR-384-5p expression promoted autophagy and inhibited apoptosis of OGD-treated neurons,which could be reversed by further 3-MA treatment.Mechanistically,circR-ZC3HC1 targeted miR-384-5p to mediate SIRT1 expression.miR-384-5p overexpression or SIRT1 knockdown in the presence of circR-ZC3HC1 overexpression in OGD-treated neurons lead to reduced autophagy and enhanced apoptosis.Conclusion:Collectively,circR-ZC3HC1 promoted neuronal autophagy to attenuate IS via miR-384-5p/SIRT1 axis.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0701202,No.2017YFB0701500 and No.2020YFB1505901)National Natural Science Foundation of China(General Program No.51474149,52072240)+3 种基金Shanghai Science and Technology Committee(No.18511109300)Science and Technology Commission of the CMC(2019JCJQZD27300)financial support from the University of Michigan and Shanghai Jiao Tong University joint funding,China(AE604401)Science and Technology Commission of Shanghai Municipality(No.18511109302).
文摘Magnesium(Mg)alloys have shown great prospects as both structural and biomedical materials,while poor corrosion resistance limits their further application.In this work,to avoid the time-consuming and laborious experiment trial,a high-throughput computational strategy based on first-principles calculations is designed for screening corrosion-resistant binary Mg alloy with intermetallics,from both the thermodynamic and kinetic perspectives.The stable binary Mg intermetallics with low equilibrium potential difference with respect to the Mg matrix are firstly identified.Then,the hydrogen adsorption energies on the surfaces of these Mg intermetallics are calculated,and the corrosion exchange current density is further calculated by a hydrogen evolution reaction(HER)kinetic model.Several intermetallics,e.g.Y_(3)Mg,Y_(2)Mg and La_(5)Mg,are identified to be promising intermetallics which might effectively hinder the cathodic HER.Furthermore,machine learning(ML)models are developed to predict Mg intermetallics with proper hydrogen adsorption energy employing work function(W_(f))and weighted first ionization energy(WFIE).The generalization of the ML models is tested on five new binary Mg intermetallics with the average root mean square error(RMSE)of 0.11 eV.This study not only predicts some promising binary Mg intermetallics which may suppress the galvanic corrosion,but also provides a high-throughput screening strategy and ML models for the design of corrosion-resistant alloy,which can be extended to ternary Mg alloys or other alloy systems.
基金the foundation from the National Key Research and Development Program of China (No. 2020YFB1505901)the support by Xiao-qin ZENG Expert Workstation in Yunnan Province, China (No. 202005AF150059)。
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11974091,51973046,U22B2044,and 21673025)the Open Projects of State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Grant No.SKLIPR2020)。
文摘Bipolar junction transistors(BJTs) are often used in spacecraft due to their excellent working characteristics. However,the complex space radiation environment induces primary knock-on atoms(PKAs) in BJTs through collisions, resulting in hard-to-recover displacement damage and affecting the performance of electronic components. In this paper, the properties of PKAs induced by typical space heavy ions(C, N, O, Fe) in BJTs are investigated using Monte Carlo simulations. The simulated results show that the energy spectrum of ion-induced PKAs is primarily concentrated in the low-energy range(17eV–100eV) and displays similar features across all tested ions. The PKAs induced by the collision of energetic ions have large forward scattering angles, mainly around 88°. Moreover, the distribution of PKAs within a transistor as a function of depth displays a peak characteristic, and the peak position is linearly proportional to the incident energy at a certain energy range. These simulation outcomes serve as crucial theoretical support for long-term semiconductor material defect evolution and ground testing of semiconductor devices.
基金This work was supported by the National Key Research and Development Program of China(2021YFB2900603)the National Natural Science Foundation of China(61831008).
文摘A dynamic multi-beam resource allocation algorithm for large low Earth orbit(LEO)constellation based on on-board distributed computing is proposed in this paper.The allocation is a combinatorial optimization process under a series of complex constraints,which is important for enhancing the matching between resources and requirements.A complex algorithm is not available because that the LEO on-board resources is limi-ted.The proposed genetic algorithm(GA)based on two-dimen-sional individual model and uncorrelated single paternal inheri-tance method is designed to support distributed computation to enhance the feasibility of on-board application.A distributed system composed of eight embedded devices is built to verify the algorithm.A typical scenario is built in the system to evalu-ate the resource allocation process,algorithm mathematical model,trigger strategy,and distributed computation architec-ture.According to the simulation and measurement results,the proposed algorithm can provide an allocation result for more than 1500 tasks in 14 s and the success rate is more than 91%in a typical scene.The response time is decreased by 40%com-pared with the conditional GA.
基金Supported by Ningbo Health Technology Project,Nos.2020Y12 and 2022Y12.
文摘Objective:Circular RNAs(circRNAs)have been shown to involve in pathological processes of ischemic stroke(IS),including autophagy.This study was designed to explore the effect of circR-ZC3HC1 on neuronal autophagy in IS and the related mechanisms.Methods:Expression of circR-ZC3HC1 in blood samples of IS patients and healthy controls was detected.Hippocampal neurons were treated with oxygen and glucose deprivation(OGD)to establish IS in vitro model.The expression of LC3 and p62 and the number of autophagosomes were examined to evaluate the autophagy level of OGD induced neurons using western blotting and transmission electron microscope.Cell apoptosis rate and the expression of cleaved caspase-3,Bax,and Bcl-2 were assessed byflow cytometry and western blotting.The binding relationships among circR-ZC3HC1,miR-384-5p,and SIRT1 were predicted and verified.Results:Low expression of circR-ZC3HC1 was found in blood samples of IS patients and OGD-treated neurons.Overexpressed circR-ZC3HC1 or inhibited miR-384-5p expression promoted autophagy and inhibited apoptosis of OGD-treated neurons,which could be reversed by further 3-MA treatment.Mechanistically,circR-ZC3HC1 targeted miR-384-5p to mediate SIRT1 expression.miR-384-5p overexpression or SIRT1 knockdown in the presence of circR-ZC3HC1 overexpression in OGD-treated neurons lead to reduced autophagy and enhanced apoptosis.Conclusion:Collectively,circR-ZC3HC1 promoted neuronal autophagy to attenuate IS via miR-384-5p/SIRT1 axis.
