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Gamma-glutamyl transferase 5 overexpression in cerebrovascular endothelial cells improves brain pathology,cognition,and behavior in APP/PS1 mice
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作者 Yanli zhang Tian Li +8 位作者 Jie Miao Zhina zhang Mingxuan Yang Zhuoran Wang Bo Yang jiawei zhang Haiting Li Qiang Su Junhong Guo 《Neural Regeneration Research》 SCIE CAS 2025年第2期533-547,共15页
In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of A... In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of Alzheimer’s disease remains unclear.This study aimed to explore the effect of GGT5 on cognitive function and brain pathology in an APP/PS1 mouse model of Alzheimer’s disease,as well as the underlying mechanism.We observed a significant reduction in GGT5 expression in two in vitro models of Alzheimer’s disease(Aβ_(1-42)-treated hCMEC/D3 and bEnd.3 cells),as well as in the APP/PS1 mouse model.Additionally,injection of APP/PS1 mice with an adeno-associated virus encoding GGT5 enhanced hippocampal synaptic plasticity and mitigated cognitive deficits.Interestingly,increasing GGT5 expression in cerebrovascular endothelial cells reduced levels of both soluble and insoluble amyloid-βin the brains of APP/PS1 mice.This effect may be attributable to inhibition of the expression ofβ-site APP cleaving enzyme 1,which is mediated by nuclear factor-kappa B.Our findings demonstrate that GGT5 expression in cerebrovascular endothelial cells is inversely associated with Alzheimer’s disease pathogenesis,and that GGT5 upregulation mitigates cognitive deficits in APP/PS1 mice.These findings suggest that GGT5 expression in cerebrovascular endothelial cells is a potential therapeutic target and biomarker for Alzheimer’s disease. 展开更多
关键词 Alzheimer’s disease amyloid-β APP/PS1 mice cerebrovascular endothelial cells cognitive deficits gamma-glutamyl transferase 5 neurovascular unit nuclear factor‐kappa B synaptic plasticity β-site APP cleaving enzyme 1
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Argatroban promotes recovery of spinal cord injury by inhibiting the PAR1/JAK2/STAT3 signaling pathway 被引量:1
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作者 Chenxi Zhao Tiangang Zhou +9 位作者 Ming Li Jie Liu Xiaoqing Zhao Yilin Pang Xinjie Liu jiawei zhang Lei Ma Wenxiang Li Xue Yao Shiqing Feng 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第2期434-439,共6页
Argatroban is a synthetic thrombin inhibitor approved by U.S.Food and Drug Administration for the treatment of thrombosis.However,whether it plays a role in the repair of spinal cord injury is unknown.In this study,we... Argatroban is a synthetic thrombin inhibitor approved by U.S.Food and Drug Administration for the treatment of thrombosis.However,whether it plays a role in the repair of spinal cord injury is unknown.In this study,we established a rat model of T10 moderate spinal cord injury using an NYU Impactor ModerⅢand performed intraperitoneal injection of argatroban for 3 consecutive days.Our results showed that argatroban effectively promoted neurological function recovery after spinal cord injury and decreased thrombin expression and activity in the local injured spinal cord.RNA sequencing transcriptomic analysis revealed that the differentially expressed genes in the argatroban-treated group were enriched in the JAK2/STAT3 pathway,which is involved in astrogliosis and glial scar formation.Western blotting and immunofluorescence results showed that argatroban downregulated the expression of the thrombin receptor PAR1 in the injured spinal cord and the JAK2/STAT3 signal pathway.Argatroban also inhibited the activation and proliferation of astrocytes and reduced glial scar formation in the spinal cord.Taken together,these findings suggest that argatroban may inhibit astrogliosis by inhibiting the thrombin-mediated PAR1/JAK2/STAT3 signal pathway,thereby promoting the recovery of neurological function after spinal cord injury. 展开更多
关键词 ARGATROBAN ASTROGLIOSIS JAK/STAT signaling pathway protease-activated receptor-1 spinal cord injury THROMBIN vimentin
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A Single-Layer Piezoelectric Composite Separator for Durable Operation of Li Metal Anode at High Rates
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作者 Yuanpeng Ji Botao Yuan +9 位作者 jiawei zhang Zhezhi Liu Shijie Zhong Jipeng Liu Yuanpeng Liu Mengqiu Yang Changguo Wang Chunhui Yang Jiecai Han Weidong He 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第1期265-274,共10页
Piezoelectric ceramic and polymeric separators have been proposed to effectively regulate Li deposition and suppress dendrite growth,but such separators still fail to satisfactorily support durable operation of lithiu... Piezoelectric ceramic and polymeric separators have been proposed to effectively regulate Li deposition and suppress dendrite growth,but such separators still fail to satisfactorily support durable operation of lithium metal batteries owing to the fragile ceramic layer or low-piezoelectricity polymer as employed.Herein,by combining PVDF-HFP and ferroelectric BaTiO_(3),we develop a homogeneous,single-layer composite separator with strong piezoelectric effects to inhibit dendrite growth while maintaining high mechanical strength.As squeezed by local protrusion,the polarized PVDF-HFP/BaTiO_(3)composite separator generates a local voltage to suppress the local-intensified electric field and further deconcentrate regional lithium-ion flux to retard lithium deposition on the protrusion,hence enabling a smoother and more compact lithium deposition morphology than the unpoled composite separator and the pure PVDF-HFP separator,especially at high rates.Remarkably,the homogeneous incorporation of BaTiO_(3)highly improves the piezoelectric performances of the separator with residual polarization of 0.086 pC cm^(-2)after polarization treatment,four times that of the pure PVDF-HFP separator,and simultaneously increases the transference number of lithium-ion from 0.45 to 0.57.Beneficial from the prominent piezoelectric mechanism,the polarized PVDF-HFP/BaTiO_(3)composite separator enables stable cyclic performances of Li||LiFePO_(4)cells for 400 cycles at 2 C(1 C=170 mA g^(-1))with a capacity retention above 99%,and for 600 cycles at 5 C with a capacity retention over 85%. 展开更多
关键词 composite separator Li metal anodes piezoelectric materials PVDF-HFP uniform Li deposition
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Gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis for ammonia production
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作者 刘学 张佳伟 +5 位作者 何弈 黄嘉敏 马晓萍 张潇漫 卢曼婷 辛煜 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第7期67-73,共7页
Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O ... Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis.In this method,NO_(x)is provided by the gliding arc discharge and then electrolyzed by Cu/Cu_(2)O after alkaline absorption.The electrical characteristics,the optical characteristics and the NO_(x)production are investigated in discharges at different input voltage and the gas flow.The dependence of ammonia production through Cu/Cu_(2)O electrocatalysis on pH value and reduction potential are determined by colorimetric method.In our study,two discharge modes are observed.At high input voltage and low gas flow,the discharge is operated with a stable plasma channel which is called the steady arc gliding discharge mode(A-G mode).As lowering input voltage and raising gas flow,the plasma channel is destroyed and high frequency breakdown occurs instead,which is known as the breakdown gliding discharge mode(B-G mode).The optimal NO_(x)production of 7.34 mmol h^(-1)is obtained in the transition stage of the two discharge modes.The ammonia yield reaches0.402 mmol h^(-1)cm^(-2)at pH value of 12.7 and reduction potential of-1.0 V versus reversible hydrogen electrode(RHE). 展开更多
关键词 gliding arc discharge nitrogen fixation Cu/Cu_(2)O catalyst electrocatalytic reduction of nitrite
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Optimizing Two-Phase Flow Heat Transfer:DCS Hybrid Modeling and Automation in Coal-Fired Power Plant Boilers
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作者 Ming Yan Caijiang Lu +3 位作者 Pan Shi Meiling zhang jiawei zhang Liang Wang 《Frontiers in Heat and Mass Transfer》 EI 2024年第2期615-631,共17页
In response to escalating challenges in energy conservation and emission reduction,this study delves into the complexities of heat transfer in two-phase flows and adjustments to combustion processes within coal-fired ... In response to escalating challenges in energy conservation and emission reduction,this study delves into the complexities of heat transfer in two-phase flows and adjustments to combustion processes within coal-fired boilers.Utilizing a fusion of hybrid modeling and automation technologies,we develop soft measurement models for key combustion parameters,such as the net calorific value of coal,flue gas oxygen content,and fly ash carbon content,within theDistributedControl System(DCS).Validated with performance test data,thesemodels exhibit controlled root mean square error(RMSE)and maximum absolute error(MAXE)values,both within the range of 0.203.Integrated into their respective automatic control systems,thesemodels optimize two-phase flow heat transfer,finetune combustion conditions,and mitigate incomplete combustion.Furthermore,this paper conducts an in-depth exploration of the generationmechanismof nitrogen oxides(NOx)and low oxygen emission reduction technology in coal-fired boilers,demonstrating a substantial reduction in furnace exit NOx generation by 30%to 40%and the power supply coal consumption decreased by 1.62 g/(kW h).The research outcomes highlight the model’s rapid responsiveness,enabling prompt reflection of transient variations in various economic indicator parameters.This provides a more effective means for real-time monitoring of crucial variables in coal-fired boilers and facilitates timely combustion adjustments,underscoring notable achievements in boiler combustion.The research not only provides valuable and practical insights into the intricacies of two-phase flow heat transfer and heat exchange but also establishes a pioneering methodology for tackling industry challenges. 展开更多
关键词 Two-phase flow coal-fired boiler oxygen content of flue gas carbon content in fly ash hybrid modeling automation control
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Study on Sealing Characteristics of Sliding Seal Assembly of Aircraft Hydraulic Actuator
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作者 Weinan Li Saixin Shi +4 位作者 Hongxia Tang Liang Chen jiawei zhang Hao Tang Jianhua Zhao 《Instrumentation》 2024年第1期18-29,共12页
The hydraulic actuator,known as the"muscle"of military aircraft,is responsible for flight attitude adjustment,trajectory control,braking turn,landing gear retracting and other actions,which directly affect i... The hydraulic actuator,known as the"muscle"of military aircraft,is responsible for flight attitude adjustment,trajectory control,braking turn,landing gear retracting and other actions,which directly affect its flight efficiency and safety.However,the sealing assembly often has the situation of over-aberrant aperture fit clearance or critical over-aberrant clearance,which increases the failure probability and degree of movable seal failure,and directly affects the flight efficiency and safety of military aircraft.In this paper,the simulation model of hydraulic actuator seal combination is established by ANSYS software,and the sealing principle is described.The change curve of contact width and contact pressure of combination seal under the action of high-pressure fluid is drawn.The effects of different oil pressure,fit clearance and other parameters on the sealing performance are analyzed.Finally,the accelerated life test of sliding seal components is carried out on the hydraulic actuator accelerated life test rig,and the surface morphology is compared and analyzed.The research shows that the O-ring is the main sealing element and the role of the check ring is to protect and support the O-ring to prevent damage caused by squeezing into the fit clearance,so the check ring bears a large load and is prone to shear failure.Excessive fit clearance is the main factor affecting the damage of the check ring,and the damage parts are mainly concentrated at the edge of the sealing surface.This paper provides a theoretical basis for the design of hydraulic actuator and the improvement of sealing performance. 展开更多
关键词 hydraulic actuator contact stress sealing characteristics maximum shear stress
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Pavement Performance Research Progress and Evaluation of Asphalt Mixture Incorporating Iron Ore Tailings
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作者 Yuefeng Zhu jiawei zhang +2 位作者 Jie Yang Gang Wang Xiangzhen Zhao 《World Journal of Engineering and Technology》 2022年第3期487-501,共15页
In order to solve the problems caused by the storage of iron ore tailings (IOTs), many researchers conducted a series of experimental studies on the reuse of IOTs. The results of many studies showed that it was feasib... In order to solve the problems caused by the storage of iron ore tailings (IOTs), many researchers conducted a series of experimental studies on the reuse of IOTs. The results of many studies showed that it was feasible to use IOTs for road engineering. This paper summarized the composition, gradation and particle characteristics of IOTs from chemical and physical aspects, and proved the feasibility of IOTs replacing traditional aggregate for asphalt concrete. Then, the research on the road performance of asphalt concrete incorporating IOTs were summarized and reviewed, including the evaluation of high-temperature stability, low-temperature crack resistance, fatigue resistance and water stability. The water stability and the improvement of adhesion between asphalt and IOTs aggregate were discussed in detail. Finally, the performance of IOTs as asphalt concrete aggregate and the existing defects were evaluated, and future research directions were proposed. 展开更多
关键词 Iron Ore Tailings CONCRETE Asphalt Mixture Adhesivity
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生殖激素产品的应用和发展趋势 被引量:4
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作者 罗昊澍 张佳伟 +1 位作者 师磊 熊剑胜 《猪业科学》 2021年第5期58-60,共3页
生殖激素是调控动物体内复杂生殖过程并影响繁殖性能的一系列的重要激素。近年来,利用生殖激素的批次化生产繁殖技术被广泛使用,提高了母猪的繁殖效率,促进了养猪业向集约化和规模化方向的发展。目前在批次化生产过程中主要采用孕马血... 生殖激素是调控动物体内复杂生殖过程并影响繁殖性能的一系列的重要激素。近年来,利用生殖激素的批次化生产繁殖技术被广泛使用,提高了母猪的繁殖效率,促进了养猪业向集约化和规模化方向的发展。目前在批次化生产过程中主要采用孕马血清促性腺激素(PMSG)和人绒毛膜促性腺激素(HCG)以及化学类激素进行繁殖调控。但是这些产品的应用仍存在一些问题,因此需要开发出成本低、活性好的高品质蛋白类生殖激素产品,应用于猪场批次化生产中,提高生猪养殖效率和降低生产成本,为提升我国乃至全球畜牧业的动物繁殖效率做出贡献,为动物和人类的健康提供重要保证。 展开更多
关键词 生殖激素 孕马血清促性腺激素 人绒毛膜促性腺激素 重组蛋白 中国仓鼠卵巢细胞
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单甲基环取代聚苯胺防腐性能的研究进展 被引量:1
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作者 张家伟 厉英 +1 位作者 胡传波 李希萌 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2018年第8期173-178,共6页
实验研究发现,取代聚苯胺或聚苯胺衍生物中存在的供电子基(如氧基、烷基、氨基等)能够有效提高聚苯胺涂层的防腐性能。其中单甲基环取代聚苯胺因其特有的高导电性、可逆的氧化还原等特性,已经成为防腐领域中的研究热点。文中通过介绍聚... 实验研究发现,取代聚苯胺或聚苯胺衍生物中存在的供电子基(如氧基、烷基、氨基等)能够有效提高聚苯胺涂层的防腐性能。其中单甲基环取代聚苯胺因其特有的高导电性、可逆的氧化还原等特性,已经成为防腐领域中的研究热点。文中通过介绍聚苯胺及其衍生物涂层的防腐性能以及不足,归纳总结了单甲基环取代聚苯胺衍生物(对位取代、间位取代、邻位取代)防腐涂层的防腐性能;复合改性材料对单甲基环取代聚苯胺衍生物涂层的防腐性能的提高;此外展望了单甲基环取代聚苯胺衍生物未来的发展趋势。 展开更多
关键词 聚苯胺 单甲基环取代聚苯胺 复合改性 防腐性能
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5G Flexible Optical Transport Networks with Large-Capacity, Low-Latency and High-Efficiency 被引量:11
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作者 Yuefeng Ji jiawei zhang +1 位作者 Yuming Xiao Zhen Liu 《China Communications》 SCIE CSCD 2019年第5期19-32,共14页
The fifth generation(5G) of mobile communications are facing big challenges, due to the proliferation of diversified terminals and unprecedented services such as internet of things(IoT), high-definition videos, virtua... The fifth generation(5G) of mobile communications are facing big challenges, due to the proliferation of diversified terminals and unprecedented services such as internet of things(IoT), high-definition videos, virtual/augmented reality(VR/AR). To accommodate massive connections and astonish mobile traffic, an efficient 5G transport network is required. Optical transport network has been demonstrated to play an important role for carrying 5G radio signals. This paper focuses on the future challenges, recent studies and potential solutions for the 5G flexible optical transport networks with the performances on large-capacity, low-latency and high-efficiency. In addition, we discuss the technology development trends of the 5G transport networks in terms of the optical device, optical transport system, optical switching, and optical networking. Finally, we conclude the paper with the improvement of network intelligence enabled by these technologies to deterministic content delivery over 5G optical transport networks. 展开更多
关键词 5G OPTICAL TRANSPORT networks OPTICAL DEVICES OPTICAL TRANSPORT system OPTICAL SWITCHING OPTICAL NETWORKING
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Stability of Cu-Mn bimetal catalysts based on different zeolites for NO_x removal from diesel engine exhaust 被引量:13
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作者 Shuang Zhao Liming Huang +3 位作者 Boqiong Jiang Min Cheng jiawei zhang Yijing Hu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第4期800-809,共10页
Cu–Mn bimetal catalysts were prepared to remove nitrogen oxides(NOx)from diesel engine exhaust at low temperatures.At a Cu/Mn ratio of 3:2,the NOx conversions at 200°C reached 65%and 90%on Cu–Mn/ZSM‐5 and Cu–... Cu–Mn bimetal catalysts were prepared to remove nitrogen oxides(NOx)from diesel engine exhaust at low temperatures.At a Cu/Mn ratio of 3:2,the NOx conversions at 200°C reached 65%and 90%on Cu–Mn/ZSM‐5 and Cu–Mn/SAPO‐34,respectively.After a hydrothermal treatment and reaction in the presence of C3H6,the activity of Cu–Mn/SAPO‐34 was more stable than that of Cu–Mn/ZSM‐5.No obvious variations in the crystal structure or dealumination were observed,whereas the physical structure was best maintained in Cu–Mn/SAPO‐34.The atomic concentration of Cu on the surface of Cu–Mn/SAPO‐34 was quite stable,and the consumption of octahedrally coordinated Cu2+could be recovered.Conversely,the proportion of octahedrally coordinated Cu2+on the surface of Cu–Mn/ZSM‐5 significantly decreased.Therefore,besides the structure,the redox cycle between Cu+and octahedrally coordinated Cu2+played an important role in the stability of the catalysts. 展开更多
关键词 Cu-Mn/SAPO-34 Cu-Mn/ZSM-5 Diesel engine exhaust Hydrothermal stability Resistance to hydrocarbons
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Provenance and tectonic setting transition as recorded in the Neoproterozoic strata, western Jiangnan Orogen:Implications for South China within Rodinia 被引量:6
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作者 jiawei zhang Taiping Ye +5 位作者 Yaran Dai Jianshu Chen Hui zhang Chuangu Dai Guohua Yuan Kaiyuan Jiang 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第5期1823-1839,共17页
The Neoproterozoic Tonian strata (ca.870-725 Ma) in the western Jiangnan Orogen archive the records of sedimentary provenance and tectonic setting which can be used to understand the geological evolution of the South ... The Neoproterozoic Tonian strata (ca.870-725 Ma) in the western Jiangnan Orogen archive the records of sedimentary provenance and tectonic setting which can be used to understand the geological evolution of the South China Continent.These strata are separated into the basement and cover sequences by a regional angular unconformity.The basement sequence can be subdivided into the lower and the upper parts by the widespread interbedded ca.840 Ma basalt with pillow structure.In the present work,234 concordant detrital zircon analyses are obtained from three Tonian sandstone samples in the Fanjingshan district,Guizhou Province.Combined with previous results,a total of 1736 analyses of detrital zircon U-Pb ages derived from 12 formations of Tonian strata in the western Jiangnan Orogen are used to decipher the integrated sedimentary and tectonic histories.The zircons from the lowermost part of the basement sequence (the Yujiagou Formation) show oval morphology and display two Paleoproterozoic age peaks at 2325 Ma and 1845 Ma which are similar with the detrital zircon age peaks from the Late Paleoproterozoic to Early Mesoproterozoic Dongchuan/Dahongshan/Hekou groups,suggesting a passive margin basin in which the sediments were mainly sourced from the southwestern Yangtze Block.However,the zircon age population of the lower part of the basement sequence (the Xiaojiahe,Huixiangping formations and their equivalents) indicates the sedimentary derivation from bidirectional sources (the ca.870 Ma arc materials in the south and the old detritus from the southwestern Yangtze Block) which is consistent with a back arc setting for the deposition of the sediments.Zircons from the upper part of the basement sequence (the Duyantang Formation and its equivalent) show euhedral and subangular morphology and display a unimodal age peak at ca.835 Ma.This sequence was possibly deposited in a convergent setting and the detritus were came from the locally distributed syn-collisional igneous rocks.The lower part of the cover sequence (the Xinzhai and Wuye formations and their equivalents) shows a distinct zircon age peak at 815-809 Ma and two subordinate peaks at 2485 Ma and 2018 Ma,suggesting that the basin had gradually transformed into a continental rift basin and received the detritus from the ca.815 Ma post-collisional magmatic rocks as well as from different Paleoproterozoic source rocks in the northern Yangtze Block.We propose a tectonic evolution model that envisages eruption of ca.840 Ma basalt in a back arc basin that existed during ca.870-835 Ma,an angular unconformity was formed during amalgamation of the Yangtze Block and the Cathaysia Block at ca.835-820 Ma and the rifting of the South China Continent was initiated at ca.800 Ma.Our study concludes that the South China Continent was formed on the periphery of the Rodinia supercontinent. 展开更多
关键词 DETRITAL zircon Fanjingshan Sibao Back arc basin PRECAMBRIAN Tonian
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Ferroptosis inhibition protects vascular endothelial cells and maintains integrity of the blood-spinal cord barrier after spinal cord injury 被引量:4
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作者 Wenxiang Li Xiaoqing Zhao +12 位作者 Rong zhang Xinjie Liu zhangyang Qi Yang zhang Weiqi Yang Yilin Pang Chenxi Zhao Baoyou Fan Ning Ran jiawei zhang Xiaohong Kong Shiqing Feng Xue Yao 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第11期2474-2481,共8页
Maintaining the integrity of the blood-spinal cord barrier is critical for the recove ry of spinal cord injury.Ferro ptosis contributes to the pathogenesis of spinal cord injury.We hypothesized that ferroptosis is inv... Maintaining the integrity of the blood-spinal cord barrier is critical for the recove ry of spinal cord injury.Ferro ptosis contributes to the pathogenesis of spinal cord injury.We hypothesized that ferroptosis is involved in disruption of the blood-s pinal cord barrier.In this study,we administe red the ferroptosis inhibitor liproxstatin-1 intraperitoneally after contusive spinal co rd injury in rats.Liproxstatin-1 improved locomotor recovery and somatosensory evoked potential electrophysiological performance after spinal cord inju ry.Liproxstatin-1 maintained blood-spinal cord barrier integrity by upregulation of the expression of tight junction protein.Liproxstatin-1 inhibited ferroptosis of endothelial cell after spinal cord injury,as shown by the immunofluorescence of an endothelial cell marker(rat endothelium cell antigen-1,RECA-1) and fe rroptosis markers Acyl-CoA synthetase long-chain family member 4 and 15-lipoxygenase.Liproxstatin-1reduced brain endothelial cell ferroptosis in vitro by upregulating glutathione peroxidase 4 and downregulating Acyl-CoA synthetase long-chain family member4 and 15-lipoxygenase.Furthermore,inflammatory cell recruitment and astrogliosis were mitigated after liproxstatin-1 treatment.In summary,liproxstatin-1im proved spinal cord injury recovery by inhibiting ferroptosis in endothelial cells and maintaining blood-s pinal co rd barrier integrity. 展开更多
关键词 blood-spinal cord barrier ferroptosis liproxstatin-1 NEUROINFLAMMATION spinal cord injury vascular endothelial cells
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Effect of Radial Resistance Gap on the Pressure Drop of a Compact Annular-Radial-Orifice Flow Magnetorheological Valve 被引量:4
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作者 Guoliang Hu jiawei zhang +1 位作者 Mingke Liao Ruqi Ding 《Journal of Beijing Institute of Technology》 EI CAS 2018年第4期535-546,共12页
A compact annular-radial-orifice flow magnetorheological(MR)valve was developed to investigate the effects of radial resistance gap on pressure drop.The fluid flow paths of this proposed MR valve consist of a single a... A compact annular-radial-orifice flow magnetorheological(MR)valve was developed to investigate the effects of radial resistance gap on pressure drop.The fluid flow paths of this proposed MR valve consist of a single annular flow channel,a single radial flow channel and an orifice flow channel through structure design.The finite element modelling and simulation analysis of the MR valve was carried out using ANSYS/Emag software to investigate the changes of the magnetic flux density and yield stress along the fluid flow paths under the four different radial resistance gaps.Moreover,the experimental tests were also conducted to evaluate the pressure drop,showing that the proposed MR valve has significantly improved its pressure drop at 0.5 mm width of the radial resistance gap when the annular resistance gap is fixed at 1 mm. 展开更多
关键词 magnetorheological(MR)valve annular-radial-orifice flow pressure drop radial resistance gap finite element analysis
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Measurement of lumber moisture content based on PCA and GSSVM 被引量:4
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作者 jiawei zhang Wenlong Song +1 位作者 Bin Jiang Mingbao Li 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第2期547-554,共8页
Lumber moisture content(LMC) is the important parameter to judge the dryness of lumber and the quality of wooden products.Nevertheless the data acquired are mostly redundant and incomplete because of the complexity of... Lumber moisture content(LMC) is the important parameter to judge the dryness of lumber and the quality of wooden products.Nevertheless the data acquired are mostly redundant and incomplete because of the complexity of the course of drying,by interference factors that exist in the dryness environment and by the physical characteristics of the lumber itself.To improve the measuring accuracy and reliability of LMC,the optimal support vector machine(SVM) algorithm was put forward for regression analysis LMC.Environmental factors such as air temperature and relative humidity were considered,the data of which were extracted with the principle component analysis method.The regression and prediction of SVM was optimized based on the grid search(GS) technique.Groups of data were sampled and analyzed,and simulation comparison of forecasting performance shows that the main component data were extracted to speed up the convergence rate of the optimum algorithm.The GS-SVM shows a better performance in solving the LMC measuring and forecasting problem. 展开更多
关键词 Lumber moisture content(LMC) Principle component analysis(PCA) Grid search(GS) Support vector machine(SVM)
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Distribution of phytoplankton in the East China Sea and the southern Yellow Sea in spring in relation to environmental variables and dimethylsulfide compounds 被引量:2
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作者 jiawei zhang Yanghang Chen +7 位作者 Xueyan Ren Vishal Patil Lin Sun Xuesong Li Junrong Liang Jun zhang Yahui Gao Changping Chen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第6期41-53,共13页
The coastal ecosystems are highly sensitive to climate change and are usually influenced by variations in phytoplankton communities and water physiochemical factors.In the present study,the phytoplankton community,chl... The coastal ecosystems are highly sensitive to climate change and are usually influenced by variations in phytoplankton communities and water physiochemical factors.In the present study,the phytoplankton community,chlorophyll a(Chl a)and their relationships with environmental variables and dimethylsulfide(DMS)and dimethylsulfoniopropionate(DMSP)were investigated in spring 2017(March 24 to April 16)in the East China Sea(26.0°-33.0°N,120.0°-128.0°E)and southern Yellow Sea(31.0°-36.0°N,120.0°-125.0°E).The spatial distributions of phytoplankton species composition and cell density were investigated by qualitative and quantitative methods and were compared with historical data to study phytoplankton species succession in the survey area.The results showed that there were 275 phytoplankton species belonging to 90 genera and 6 phyla in the survey area,of which 208 species belonged to 62 genera of Bacillariophyta and 56 species belonged to 20 genera of Pyrrophyta.The dominant phytoplankton species were Skeletonema dohrnii,Chaetoceros vanheurckii and Prorocentrum donghaiense.The phytoplankton cell densities ranged from 0.06×10^(4)cells/L to 418.73×10^(4)cells/L,with an average value of 21.46×10^(4)cells/L.In spring,the average ratio of Bacillariophyta/Pyrrophyta was41.13 for the entire study area.The areas with high phytoplankton cell density were mainly distributed in the northern South Yellow Sea and offshore waters of the East China Sea.According to a canonical correspondence analysis among phytoplankton and environmental parameters,the water Chl a concentrations were notably consistent with phytoplankton cell density(P<0.001),and both showed significant negative correlations with salinity and nitrite(P<0.05)and significant positive correlations with dissolved oxygen and pH(P<0.001).There was a significant positive correlation between diatom(both in cell density and in dominant species)and DMS(P<0.05),which indicated that diatoms play a greater role in DMS production in this investigated area. 展开更多
关键词 PHYTOPLANKTON DISTRIBUTION East China Sea southern Yellow Sea DIMETHYLSULFONIOPROPIONATE
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Protoraphis Simonsen, a newly recorded marine epizoic diatom genus for China 被引量:2
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作者 Lang Li Changping Chen +3 位作者 Lin Sun jiawei zhang Junrong Liang Yahui Gao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2020年第4期120-126,共7页
Epizoic diatoms on marine copepods are common in nature and may have a special ecological relationship with their hosts.However,this special ecological group is not well known,and it has only rarely been studied in th... Epizoic diatoms on marine copepods are common in nature and may have a special ecological relationship with their hosts.However,this special ecological group is not well known,and it has only rarely been studied in the China seas.To address this knowledge gap,the species diversity and classification of epizoic diatoms on planktonic copepods were studied with samples collected from the East China Sea.In the present study,a marine araphid diatom genus Protoraphis and its type species,Pr.hustedtiana,were observed and identified by light and electron microscopy,thus representing the first record of this genus and its type species in China.This genus is characterized by a median sternum strongly bent to opposite sides and terminate in two transapical grooves at the valve ends.Protoraphis hustedtiana was found to be epizoic on the posterior body appendages and segments of the marine calanoid copepod Candacia bradyi.An internal view shows a complex,ear-shaped process that is close to the apical slit field.The ecological habitats and geographical distributions of Protoraphis were also discussed,and,together with complementary morphological studies,our results have increased the number of records for marine epizoic diatoms to three genera with three species in China,including Pseudohimantidium and Pseudofalcula. 展开更多
关键词 marine epizoic diatom copepod Protoraphis newly recorded genus ear-shaped process
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Effects of Stacking Sequence and Impactor Diameter on Impact Damage of Glass Fiber Reinforced Aluminum Alloy Laminate 被引量:2
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作者 Zhengong Zhou Shuang Tian jiawei zhang 《Computers, Materials & Continua》 SCIE EI 2016年第5期105-121,共17页
The methods of numerical simulation and test are combined to analyze the impact behavior of glass fiber reinforced aluminum alloy laminate(GLARE).A new failure criteria is proposed to obtain the impact failure of GLAR... The methods of numerical simulation and test are combined to analyze the impact behavior of glass fiber reinforced aluminum alloy laminate(GLARE).A new failure criteria is proposed to obtain the impact failure of GLARE,and combined with material progressive damage method by writing code of LS-DYNA.Low velocity impact test of GLARE is employed to validate the feasibility of the finite element model established.The simulation results have been shown that progressive damage finite element model established is reliable.Through the application of the finite element model established,the delamination of GLARE evolution progress is simulated,various failure modes of GLARE during impact are obtained,and the effects of stacking sequence and impactor diameter on the impact damage of GLARE are obtained. 展开更多
关键词 GLARE Impact behavior Progressive damage Finite element method Impact test
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Data Mining and Spatial Analysis of Social Media Text Based on the BERT-CNN Model to Achieve Situational Awareness: a Case Study of COVID-19 被引量:5
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作者 jiawei zhang Hua QI 《Journal of Geodesy and Geoinformation Science》 2022年第2期38-48,共11页
In response to the COVID-19,social media big data has played an important role in epidemic warning,tracking the source of infection,and public opinion monitoring,providing strong technical support for China’s epidemi... In response to the COVID-19,social media big data has played an important role in epidemic warning,tracking the source of infection,and public opinion monitoring,providing strong technical support for China’s epidemic prevention and control work.The paper used Sina Weibo posts related to COVID-19 hashtags as the data source,and built a BERT-CNN deep learning model to perform fine-grained and high-precision topic classificationon massive social media posts.Taking Shenzhen as a region of interest,we mined the“epidemic data bulletin”and“daily life impact”posts during the epidemic for spatial analysis.The results show that the confirmed communities and designated hospitals in Shenzhen as a whole present the characteristics of“sparse east and dense west”,and there is a strong positive spatial correlation between the number of confirmed cases and social media response.Specifically,Nanshan District,Futian District and Luohu District have more confirmed cases due to large population movements and dense transportation networks,and social media has responded more violently,and people’s lives have been greatly affected.However,Yantian District,Pingshan District and Dapeng New District showed opposite characteristics.The case study results further show that using deep learning methods to mine text information in social media is scientifically feasible for improving situational awareness and decision support during the COVID-19. 展开更多
关键词 COVID-19 Sina Weibo BERT-CNN topic classification situational awareness
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Adaptive Radiative Thermal Camouflage via Synchronous Heat Conduction 被引量:2
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作者 jiawei zhang Shiyao Huang Run Hu 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第1期19-23,共5页
The advent of transformation thermotics has seen a boom in development of thermal metamaterials with a variety of thermal functionalities,including phenomena such as thermal cloaking and camouflage.However,most therma... The advent of transformation thermotics has seen a boom in development of thermal metamaterials with a variety of thermal functionalities,including phenomena such as thermal cloaking and camouflage.However,most thermal metamaterials-based camouflage devices only tune in-plane heat conduction,which may fail to conceal a target from out-of-plane detection.We propose an adaptive radiative thermal camouflage via tuning out-ofplane transient heat conduction,and it is validated by both simulation and experiment.The physics underlying the performance of our adaptive thermal camouflage is based on real-time synchronous heat conduction through the camouflage device and the background plate,respectively.The proposed concept and device represent a promising new approach to fabrication of conductive thermal metamaterials,providing a feasible and effective way to achieve adaptive thermal camouflage. 展开更多
关键词 conduction TRANSIENT PLANE
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