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A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures
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作者 Wei WEI Feng GUAN xin fang 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第7期1171-1188,共18页
A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave insulation.It consists ... A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave insulation.It consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and narrow.The bandgap mechanisms,vibration isolation properties,effects of key parameters,and robustness to complex conditions are clarified.As experimentally demonstrated,the wave-insulating isolator can improve the vibration insulation in the ranges of[50 Hz,180 Hz]and[260 Hz,400 Hz]by 15 dB and 25 dB,respectively,in contrast to the conventional isolator with the same first resonant frequency. 展开更多
关键词 metamaterial and metastructure vibration isolation bandgap wave insulation PLATE
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Nonlinear metamaterial enabled aeroelastic vibration reduction of a supersonic cantilever wing plate
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作者 Peng SHENG xin fang +1 位作者 Dianlong YU Jihong WEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第10期1749-1772,共24页
The violent vibration of supersonic wings threatens aircraft safety.This paper proposes the strongly nonlinear acoustic metamaterial(NAM)method to mitigate aeroelastic vibration in supersonic wing plates.We employ the... The violent vibration of supersonic wings threatens aircraft safety.This paper proposes the strongly nonlinear acoustic metamaterial(NAM)method to mitigate aeroelastic vibration in supersonic wing plates.We employ the cantilever plate to simulate the practical behavior of a wing.An aeroelastic vibration model of the NAM cantilever plate is established based on the mode superposition method and a modified third-order piston theory.The aerodynamic properties are systematically studied using both the timedomain integration and frequency-domain harmonic balance methods.While presenting the flutter and post-flutter behaviors of the NAM wing,we emphasize more on the preflutter broadband vibration that is prevalent in aircraft.The results show that the NAM method can reduce the low-frequency and broadband pre-flutter steady vibration by 50%-90%,while the post-flutter vibration is reduced by over 95%,and the critical flutter velocity is also slightly delayed.As clarified,the significant reduction arises from the bandgap,chaotic band,and nonlinear resonances of the NAM plate.The reduction effect is robust across a broad range of parameters,with optimal performance achieved with only 10%attached mass.This work offers a novel approach for reducing aeroelastic vibration in aircraft,and it expands the study of nonlinear acoustic/elastic metamaterials. 展开更多
关键词 nonlinear acoustic metamaterial(NAM) hypersonic aeroelastic vibration vibration reduction fluid-structure interaction
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Local resonance metamaterial-based integrated design for suppressing longitudinal and transverse waves in fluid-conveying pipes
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作者 Donghai HAN Qi JIA +4 位作者 Yuanyu GAO Qiduo JIN xin fang Jihong WEN Dianlong YU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第10期1821-1840,共20页
To solve the problem of low broadband multi-directional vibration control of fluid-conveying pipes,a novel metamaterial periodic structure with multi-directional wide bandgaps is proposed.First,an integrated design me... To solve the problem of low broadband multi-directional vibration control of fluid-conveying pipes,a novel metamaterial periodic structure with multi-directional wide bandgaps is proposed.First,an integrated design method is proposed for the longitudinal and transverse wave control of fluid-conveying pipes,and a novel periodic structure unit model is constructed for vibration reduction.Based on the bandgap vibration reduction mechanism of the acoustic metamaterial periodic structure,the material parameters,structural parameters,and the arrangement interval of the periodic structure unit are optimized.The finite element method(FEM)is used to predict the vibration transmission characteristics of the fluid-conveying pipe installed with the vibration reduction periodic structure.Then,the wave/spectrum element method(WSEM)and experimental test are used to verify the calculated results above.Lastly,the vibration attenuation characteristics of the structure under different conditions,such as rubber material parameters,mass ring material,and fluid-structure coupling effect,are analyzed.The results show that the structure can produce a complete bandgap of 46 Hz-75 Hz in the low-frequency band below 100 Hz,which can effectively suppress the low broadband vibration of the fluidconveying pipe.In addition,a high damping rubber material is used in the design of the periodic structure unit,which realizes the effective suppression of each formant peak of the pipe,and improves the vibration reduction effect of the fluid-conveying pipe.Meanwhile,the structure has the effect of suppressing both bending vibration and longitudinal vibration,and effectively inhibits the transmission of transverse waves and longitudinal waves in the pipe.The research results provide a reference for the application of acoustic metamaterials in the multi-directional vibration control of fluid-conveying pipes. 展开更多
关键词 fluid-conveying pipe acoustic metamaterial multi-directional vibration reduction local resonance
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The SmMYB36-SmERF6/SmERF115 module regulates the biosynthesis of tanshinones and phenolic acids in salvia miltiorrhiza hairy roots 被引量:4
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作者 Qi Li xin fang +3 位作者 Ying Zhao Ruizhi Cao Juane Dong Pengda Ma 《Horticulture Research》 SCIE CSCD 2023年第1期160-171,共12页
Tanshinone and phenolic acids are the most important active substances of Salvia miltiorrhiza,and the insight into their transcriptional regulatory mechanisms is an essential process to increase their content in vivo.... Tanshinone and phenolic acids are the most important active substances of Salvia miltiorrhiza,and the insight into their transcriptional regulatory mechanisms is an essential process to increase their content in vivo.SmMYB36 has been found to have important regulatory functions in the synthesis of tanshinone and phenolic acid;paradoxically,its mechanism of action in S.miltiorrhiza is not clear.Here,we demonstrated that SmMYB36 functions as a promoter of tanshinones accumulation and a suppressor of phenolic acids through the generation of SmMYB36 overexpressed and chimeric SmMYB36-SRDX(EAR repressive domain)repressor hairy roots in combination with transcriptomic-metabolomic analysis.SmMYB36 directly down-regulate the key enzyme gene of primary metabolism,SmGAPC,up-regulate the tanshinones biosynthesis branch genes SmDXS2,SmGGPPS1,SmCPS1 and down-regulate the phenolic acids biosynthesis branch enzyme gene,SmRAS.Meanwhile,SmERF6,a positive regulator of tanshinone synthesis activating SmCPS1,was up-regulated and SmERF115,a positive regulator of phenolic acid biosynthesis activating SmRAS,was down-regulated.Furthermore,the seven acidic amino acids at the C-terminus of SmMYB36 are required for both self-activating domain and activation of target gene expression.As a consequence,this study contributes to reveal the potential relevance of transcription factors synergistically regulating the biosynthesis of tanshinone and phenolic acid. 展开更多
关键词 PHENOLIC ROOTS SYNTHESIS
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The relationship among amyloid-βdeposition,sphingomyelin level,and the expression and function of P-glycoprotein in Alzheimer’s disease pathological process 被引量:1
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作者 Zi-Kang xing Li-Sha Du +6 位作者 xin fang Heng Liang Sheng-Nan Zhang Lei Shi Chun-Xiang Kuang Tian-Xiong Han Qing Yang 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第6期1300-1307,共8页
In Alzheimer’s disease,the transporter P-glycoprotein is responsible for the clearance of amyloid-βin the brain.Amyloid-βcorrelates with the sphingomyelin metabolism,and sphingomyelin participates in the regulation... In Alzheimer’s disease,the transporter P-glycoprotein is responsible for the clearance of amyloid-βin the brain.Amyloid-βcorrelates with the sphingomyelin metabolism,and sphingomyelin participates in the regulation of P-glycoprotein.The amyloid cascade hypothesis describes amyloid-βas the central cause of Alzheimer’s disease neuropathology.Better understanding of the change of P-glycoprotein and sphingomyelin along with amyloid-βand their potential association in the pathological process of Alzheimer’s disease is critical.Herein,we found that the expression of P-glycoprotein in APP/PS1 mice tended to increase with age and was significantly higher at 9 and 12 months of age than that in wild-type mice at comparable age.The functionality of P-glycoprotein of APP/PS1 mice did not change with age but was significantly lower than that of wild-type mice at 12 months of age.Decreased sphingomyelin levels,increased ceramide levels,and the increased expression and activity of neutral sphingomyelinase 1 were observed in APP/PS1 mice at 9 and 12 months of age compared with the levels in wild-type mice.Similar results were observed in the Alzheimer’s disease mouse model induced by intracerebroventricular injection of amyloid-β1-42 and human cerebral microvascular endothelial cells treated with amyloid-β1-42.In human cerebral microvascular endothelial cells,neutral sphingomyelinase 1 inhibitor interfered with the changes of sphingomyelin metabolism and P-glycoprotein expression and functionality caused by amyloid-β1-42 treatment.Neutral sphingomyelinase 1 regulated the expression and functionality of P-glycoprotein and the levels of sphingomyelin and ceramide.Together,these findings indicate that neutral sphingomyelinase 1 regulates the expression and function of P-glycoprotein via the sphingomyelin/ceramide pathway.These studies may serve as new pursuits for the development of anti-Alzheimer’s disease drugs. 展开更多
关键词 Alzheimer’s disease amyloid-β APP/PS1 mice CERAMIDE ezrin-radixin-moesin human cerebral microvascular endothelial cells neutral sphingomyelinase 1 P-GLYCOPROTEIN sphingomyelin synthase SPHINGOMYELIN
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A combined finite element and deep learning network for structural dynamic response estimation on concrete gravity dam subjected to blast loads 被引量:1
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作者 xin fang Heng Li +3 位作者 She-rong Zhang Xiao-hua Wang Chao Wang Xiao-chun Luo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期298-313,共16页
Social infrastructures such as dams are likely to be exposed to high risk of terrorist and military attacks,leading to increasing attentions on their vulnerability and catastrophic consequences under such events.This ... Social infrastructures such as dams are likely to be exposed to high risk of terrorist and military attacks,leading to increasing attentions on their vulnerability and catastrophic consequences under such events.This paper tries to develop advanced deep learning approaches for structural dynamic response prediction and dam health diagnosis.At first,the improved long short-term memory(LSTM)networks are proposed for data-driven structural dynamic response analysis with the data generated by a single degree of freedom(SDOF)and the finite numerical simulation,due to the unavailability of abundant practical structural response data of concrete gravity dam under blast events.Three kinds of LSTM-based models are discussed with the various cases of noise-contaminated signals,and the results prove that LSTM-based models have the potential for quick structural response estimation under blast loads.Furthermore,the damage indicators(i.e.,peak vibration velocity and domain frequency)are extracted from the predicted velocity histories,and their relationship with the dam damage status from the numerical simulation is established.This study provides a deep-learning based structural health monitoring(SHM)framework for quick assessment of dam experienced underwater explosions through blastinduced monitoring data. 展开更多
关键词 Deep learning Structural health monitoring Dynamic response Concrete gravity dam
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爆炸冲击载荷下无线起爆浮标动力响应研究 被引量:1
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作者 李亚伟 雷宇 +2 位作者 李志文 辛芳 王凯民 《舰船科学技术》 北大核心 2023年第2期52-59,共8页
针对实航试验中无线起爆浮标的水下爆炸抗冲击防护等问题,利用声固耦合算法,根据对水下爆炸实航环境的分析,确定水下爆炸数值模拟工况,展开无线起爆浮标的水下爆炸冲击响应数值模拟,并利用GeersHunter经验公式计算水下爆炸载荷压力-时... 针对实航试验中无线起爆浮标的水下爆炸抗冲击防护等问题,利用声固耦合算法,根据对水下爆炸实航环境的分析,确定水下爆炸数值模拟工况,展开无线起爆浮标的水下爆炸冲击响应数值模拟,并利用GeersHunter经验公式计算水下爆炸载荷压力-时间曲线,验证了声固耦合算法数值模拟冲击波载荷施加的可靠性。结果表明,声固耦合算法计算的冲击波载荷精度平均误差为2.89%。根据对浮标结构的塑性响应分析,将浮标器件舱底部板架的变形分为“中心凸起”与“中心凹陷”2种变形模式,为无线起爆浮标结构及器件舱设备安装基座的抗冲击设计提供一定参考。 展开更多
关键词 水下爆炸 无线起爆浮标 数值模拟 声固耦合 动力响应
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体育行会内部纠纷解决机制的法治化进路——兼评内部纠纷解决机制和体育仲裁关系 被引量:1
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作者 辛芳 欧阳静怡 《河北体育学院学报》 2023年第4期40-45,共6页
2022年6月新修订的《体育法》规定了体育仲裁制度,鼓励体育组织建立内部纠纷解决机制。运用文献资料法、案例分析法等梳理体育行会内部纠纷解决机制的现状和存在的问题。引入治理理论、商谈论,提出以合法性原则、正当法律程序原则和司... 2022年6月新修订的《体育法》规定了体育仲裁制度,鼓励体育组织建立内部纠纷解决机制。运用文献资料法、案例分析法等梳理体育行会内部纠纷解决机制的现状和存在的问题。引入治理理论、商谈论,提出以合法性原则、正当法律程序原则和司法最终原则为指导的层次性优化路径。建议,应建立独立的体育行业自治组织,明确内部纠纷解决机构的地位和职能,修改有关章程和仲裁委员会工作规则,保障内部纠纷解决程序正当,加强体育纠纷解决机制的相互衔接,完善体育行会内部纠纷解决机制监督体系。 展开更多
关键词 体育行会 体育纠纷 内部纠纷解决机制 体育仲裁 法治化
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Damage in hybrid corrugated core sandwich structures under high velocity hail ice impact:A numerical study
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作者 Chao Zhang xin fang +2 位作者 Jose L.Curiel-Sosa Tinh Quoc Bui Chunjian Mao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第9期217-236,共20页
Potential damage in composite structures caused by hail ice impact is an essential safety threat to the aircraft in flight.In this study,a nonlinear finite element(FE)model is developed to investigate the dynamic resp... Potential damage in composite structures caused by hail ice impact is an essential safety threat to the aircraft in flight.In this study,a nonlinear finite element(FE)model is developed to investigate the dynamic response and damage behavior of hybrid corrugated sandwich structures subjected to high velocity hail ice impact.The impact and breaking behavior of hail are described using the FE-smoothed particle hydrodynamics(FE-SPH)method.A rate-dependent progressive damage model is employed to capture the intra-laminar damage response;cohesive element and surface-based cohesive contact are implemented to predict the inter-laminar delamination and sheet/core debonding phenomena respectively.The transient processes of sandwich structure under different hail ice impact conditions are analyzed.Comparative analysis is conducted to address the influences of core shape and impact position on the impact performance of sandwich structures and the corresponding energy absorption characteristics are also revealed. 展开更多
关键词 Sandwich structure Hail ice impact Damage behavior Energy absorption FE-SPH modeling
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Development of a pressure coring system for the investigation of deep underground exploration
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作者 Da Guo Ling Chen +8 位作者 Zhongya Zhou Dingming Wang Yiwei Zhang Xun Yang xin fang Xiaojun Wang Heping Lu Lin Dai Heping Xie 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第11期1351-1364,共14页
To provide a more accurate evaluation of the scale of deep underground resources,a new pressure coring system was carefully developed and its strength and safety of the engineering were verified by theoretical analyse... To provide a more accurate evaluation of the scale of deep underground resources,a new pressure coring system was carefully developed and its strength and safety of the engineering were verified by theoretical analyses and numerical simulation.The designed pressure coring system can obtain cores with length of 3 m and diameter of 50 mm at 70 MPa.The results of the ball-drop operation experiment demonstrate that differential motion assembly can effectively cut a safety pin by applying a tensile force of 4852 N,and it can lift the core tube through the center pole to complete a series of mechanical actions to seal the pressure.Additionally,by maintaining pressures at 70 MPa for 30 min,the pressure sealing capacity of the system was proven.Furthermore,a core sample with a diameter of 50 mm was obtained through a core drilling experiment and the coring performance of the pressure coring system was verified.This study can not only enrich the existing onshore coring technology but also provide a theoretical guide and design criteria for the development of similar pressure coring systems to meet the demand for deeper underground exploration. 展开更多
关键词 Underground exploration In-situ coring Pressure coring Oil and gas production
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Observation of the effect of angiojet to treat acute lower extremity arterial embolization
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作者 Xiao-Hu Meng Xu-Pin Xie +5 位作者 Yong-Chang Liu Chang-Pin Huang Lin-Jun Wang Han-Yi Liu xin fang Guo-Hui Zhang 《World Journal of Clinical Cases》 SCIE 2023年第15期3491-3501,共11页
BACKGROUND Through significant advances in the treatment of peripheral arterial occlusive disease,acute ischemia of the lower extremity is still associated with significant morbidity,limb threat and mortality.The two ... BACKGROUND Through significant advances in the treatment of peripheral arterial occlusive disease,acute ischemia of the lower extremity is still associated with significant morbidity,limb threat and mortality.The two main causes of acute ischemia in lower extremities are arterial embolism and atherosclerotic arteries.Timely recognition and treatment of acute limb ischemia in emergency situations is essential in order to minimize the duration of ischemia.AIM To investigate the application effect of angiojet thrombolysis in the treatment of acute lower extremity arterial embolization.METHODS Sixty-two patients with acute lower extremity arterial embolization admitted to our hospital from May 2018 to May 2020 were selected.Among them,the observation group(twenty-eight cases)had received angiojet thrombolysis,and the control group(thirty-four cases)had received femoral artery incision and thrombectomy.After thrombus clearance,significant residual stenosis of the lumen was combined with balloon dilation and/or stent implantation.When the thrombus removal was not satisfactory,catheter-directed thrombolysis was performed.The incidence of postoperative complications,recurrence rate and recovery of the two groups were compared.RESULTS There were no significant differences in postoperative recurrence(target vessel reconstruction rate),anklebrachial index and the incidence of postoperative complications between the two groups(P>0.05);there were statistically significant differences in postoperative pain score and postoperative rehabilitation between the two groups(P<0.05).CONCLUSION The application of angiojet in the treatment of acute lower limb artery thromboembolism disease is safe and effective,minimally invasive,quicker recovery after operation,less postoperative complications,which is more suitable for the treatment of femoral popliteal arterial thromboembolism lesions.If the thrombus removal is not satisfactory,the combination of coronary artery aspiration catheter and catheterized directed thrombolysis can be used.Balloon dilation and stent implantation can be considered for obvious lumen stenosis. 展开更多
关键词 Acute lower extremity arterial embolism Angiojet thrombectomy Postoperative complications Ankle brachial index Postoperative rehabilitation
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多旋翼植保无人机与常规喷施缩节胺对棉花生长调控效应比较 被引量:9
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作者 赵静 辛芳 +5 位作者 周月婷 赵昌荣 韩小强 刘政 林克剑 付威 《新疆农业科学》 CAS CSCD 北大核心 2018年第11期2096-2104,共9页
【目的】分析JT-30多旋翼植保无人机喷施缩节胺(DPC)对调节棉花生长的影响,研究植保无人机在棉花化控作业中的应用效果,为植保无人机在棉花化控作业的应用提供指导。【方法】与喷杆式喷雾机作业相比,采用JT-30六旋翼植保无人机喷施DPC作... 【目的】分析JT-30多旋翼植保无人机喷施缩节胺(DPC)对调节棉花生长的影响,研究植保无人机在棉花化控作业中的应用效果,为植保无人机在棉花化控作业的应用提供指导。【方法】与喷杆式喷雾机作业相比,采用JT-30六旋翼植保无人机喷施DPC作业,分析其对棉花株高、果枝长度、节间距等的影响。【结果】JT-30植保无人机喷施DPC 5、10、14 d后能够有效抑制棉花的株高,抑制率分别为7.26%、15.81%和21.17%;喷杆喷雾机作喷施作业后对应的抑制率为8.55%、16.81%和22.80%;JT-30植保无人机喷施DPC对棉花株高的抑制效果与喷杆式喷雾机作业效果相当。在果枝长度、节间长度和果枝始节高度等指标上表现出了相似的结果,且高浓度DPC没有对棉花表现出药害作用。【结论】植保无人机喷施缩节胺可以有效促进棉花营养生长向生殖生长的转移、塑造良好株型、提高成铃率,且高浓度DPC对棉花无药害,具有与常规喷施相当的效果。 展开更多
关键词 棉花 植保无人机 缩节胺 生长调控
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凡纳滨对虾TOR蛋白下游信号传导因子eIF4E2和eIF4E1A基因克隆与功能分析
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作者 辛芳 王雷 +3 位作者 刘梅 王宝杰 蒋克勇 孙国琼 《海洋科学》 CAS CSCD 北大核心 2016年第12期71-81,共11页
为研究mTOR信号通路在凡纳滨对虾(Litopenaeus vannamei)氨基酸代谢中的调控作用,本研究利用RACE技术首次克隆获得了凡纳滨对虾肌肉组织中eif4e2和eif4e1a基因的全长c DNA序列。eif4e2基因c DNA序列全长1 069 bp,开放阅读框699 bp,编码... 为研究mTOR信号通路在凡纳滨对虾(Litopenaeus vannamei)氨基酸代谢中的调控作用,本研究利用RACE技术首次克隆获得了凡纳滨对虾肌肉组织中eif4e2和eif4e1a基因的全长c DNA序列。eif4e2基因c DNA序列全长1 069 bp,开放阅读框699 bp,编码232个氨基酸;eif4e1a基因c DNA序列全长3579bp,开放阅读框627bp,编码208个氨基酸。氨基酸序列比对和进化分析均证实eIF4E2和eIF4E1A为目前已知的eIF4E家族蛋白的同源蛋白。利用实时荧光定量PCR的方法研究了eif4e2和eif4e1a基因在凡纳滨对虾不同组织中的表达差异以及注射雷帕霉素或氨基酸后肌肉中eif4e2和eif4e1a基因表达量的变化情况,探讨了eif4e2和eif4e1a基因在细胞生长中的调控作用。结果表明,凡纳滨对虾eif4e2和eif4e1a基因在眼柄、肝胰脏、肠道、胃、鳃丝和肌肉等组织中均有表达;其中eif4e2基因在肌肉中的表达量显著高于其他组织(P<0.05),eif4e1a基因在肠道和肌肉中都有较高表达量,且在肠道中的表达量显著高于其在肌肉中的表达量(P<0.05);注射雷帕霉素后2 h内肌肉中eif4e2和eif4e1a基因表达量都出现显著下降(P<0.05);肌肉中eif4e1a基因的表达量在单独注射亮氨酸或精氨酸4 h内均未出现变化,但在同时注射亮氨酸和精氨酸后表达量显著增加(P<0.05);肌肉中eif4e2基因在注射亮氨酸、精氨酸及亮氨酸加精氨酸后表达量都明显提高(P<0.05),且同时注射亮氨酸和精氨酸后,基因表达变量明显比单独注射亮氨酸或精氨酸后变化量大。本研究从动物分子营养学角度出发,克隆了凡纳滨对虾mTOR信号通路中eif4e2和eif4e1a两个基因,并证明其能够通过mTOR信号通路接收不同氨基酸信号来调控细胞生长,对于深入了解对虾的生长和代谢调控机制、饲料配方的优化以及建立合理的养殖管理模式都具有重要的意义。 展开更多
关键词 EIF4E 凡纳滨对虾(Litopenaeusvannamei) MTOR 氨基酸 生长
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多旋翼植保无人机棉花飞防作业效果 被引量:9
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作者 娄朝霞 温浩军 +3 位作者 张斌 辛芳 韩小强 付威 《新疆农业科学》 CAS CSCD 北大核心 2019年第3期537-543,共7页
【目的】研究植保无人机喷施作业雾滴的沉积分布规律和病虫害防治效果,为植保无人机田间作业提供理论依据和技术支持。【方法】使用无人机和喷杆喷雾机进行喷施试验,以卡罗米特纸卡和滤纸作为取样器采集雾滴,研究雾滴在棉花冠层的沉积规... 【目的】研究植保无人机喷施作业雾滴的沉积分布规律和病虫害防治效果,为植保无人机田间作业提供理论依据和技术支持。【方法】使用无人机和喷杆喷雾机进行喷施试验,以卡罗米特纸卡和滤纸作为取样器采集雾滴,研究雾滴在棉花冠层的沉积规律,比较两种植保机械的病虫害防治效果。【结果】在有效喷幅范围内,无人机喷施作业雾滴主要集中在棉花冠层上部,棉花冠层中部和下部雾滴沉积量和覆盖率均较低;无人机施药雾滴在上风向和下风向的飘移量有显著差异,上风向雾滴平均飘移百分比为4.93%,下风向平均飘移百分比为14.96%,且波动较大;JT-30植保无人机和3W-1000Y悬挂式喷杆喷雾机在施药7d后对棉蚜防治效果较好,在施药后15d对棉叶螨防治效果较好。【结论】雾滴在棉花冠层的穿透性较差,下风向雾滴飘移现象较突出,对蚜虫的防治效果较好。 展开更多
关键词 棉花 沉积量 穿透性 无人机 防治效果
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宫内窘迫新生儿发生缺氧缺血性脑病的危险因素分析 被引量:38
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作者 于子芮 刘春阳 +4 位作者 方心 张玮琳 孟祥祎 张伟 徐辉 《中国现代医学杂志》 CAS 2019年第14期69-72,共4页
目的研究具有宫内窘迫暴露因素的新生儿发生缺氧缺血性脑病(HIE)的危险因素。方法收集2016年6月—2018年3月于佳木斯大学附属第一医院收治的具有宫内窘迫暴露因素,但尚未确诊为HIE的患儿作为病例组。选取同一居住区、性别比例、民族、... 目的研究具有宫内窘迫暴露因素的新生儿发生缺氧缺血性脑病(HIE)的危险因素。方法收集2016年6月—2018年3月于佳木斯大学附属第一医院收治的具有宫内窘迫暴露因素,但尚未确诊为HIE的患儿作为病例组。选取同一居住区、性别比例、民族、年龄相差3个月左右且未罹患HIE儿童作为对照组,对两组临床资料进行Logistic回归分析。结果单因素Logistic回归分析结果显示,县镇医院分娩、母亲文化程度低(小学及以下)、居室周围环境差、早产(孕周<37周)、分娩时异常、出生体重低(<2500g)、孕期及新生儿各因素比较,差异有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,出生体重低<2500g[Ol^R=9.268(95%CI:1.765,30.908),P=0.005]、孕周<37周[O^R=16.036(95%CI:5.906,49.133),P=0.005]、母亲文化程度低[O^R=2.392(95%CI:1.202,4.961),P=0.000]、新生儿肌张力高[O^R=14.160(95%CI:5.436,36.680),P=0.027]及新生儿出生窒息[O^R=14.051(95%CI:1.575,125.361),P=0.006]是HIE发病的影响因素。结论孕期和围产期危险因素与宫内窘迫有协同作用,增加HIE发病风险。 展开更多
关键词 缺氧缺血 婴儿 新生 胎儿窘迫
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K型小麦雄性不育系绒毡层结构变化及相关基因的表达分析 被引量:3
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作者 翟晓光 辛芳 +5 位作者 韩玉翠 夏雪姣 朱婷 菅明阳 丁勤 马翎健 《麦类作物学报》 CAS CSCD 北大核心 2018年第12期1400-1407,共8页
为揭示K型小麦雄性不育系的败育时期和败育机制,以K型小麦雄性不育系K519A及其保持系519B为材料,采用半薄和超薄树脂切片法对花药绒毡层进行显微和亚显微结构观察,并对孢粉素转运相关基因RAFTIN1和绒毡层细胞降解相关基因APs在不同生育... 为揭示K型小麦雄性不育系的败育时期和败育机制,以K型小麦雄性不育系K519A及其保持系519B为材料,采用半薄和超薄树脂切片法对花药绒毡层进行显微和亚显微结构观察,并对孢粉素转运相关基因RAFTIN1和绒毡层细胞降解相关基因APs在不同生育时期的表达模式进行分析。结果表明,与保持系相比,不育系花药绒毡层在四分体时期提前降解,部分绒毡层细胞脱离中层侵入药室内,发育至二核和三核期绒毡层细胞只剩下细胞轮廓和少量附着的乌氏体。不育系小孢子细胞壁在单核期开始增厚,是同时期保持系小孢子细胞壁厚度的2.35倍,发育至二核期小孢子细胞壁继续增厚,但三核期不育系小孢子细胞壁比保持系小孢子细胞壁薄,仅是保持系花粉粒细胞壁厚度的89%,并且三核期不育系花粉粒出现畸形和质壁分离的异常现象。自小孢子母细胞时期至单核期,不育系中RAFTIN1和APs基因的相对表达量都显著高于保持系,但在二核期不育系中的相对表达量显著低于保持系。推测K型小麦雄性不育系K519A的败育可能发生在四分体期和二核期。RAFTIN1和APs基因的表达模式与细胞学观察结果相契合,故推测这两个基因很可能参与了K型不育系K519A的不育过程。 展开更多
关键词 小麦 雄性不育 绒毡层 显微结构 基因表达
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论政府在社会化技能培训中的合理定位
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作者 陆玲 辛芳 《安徽冶金科技职业学院学报》 2020年第4期53-55,共3页
劳动者及新成长劳动力进行社会化培训,是解决目前我国“就业难”问题的重要举措。我国政府在社会化技能培训中扮演了主导的角色,既是培训的直接提供者,也是培训结果的评判者,却在行政权限、质量把关和监督监管方面存在明显的缺陷。因此... 劳动者及新成长劳动力进行社会化培训,是解决目前我国“就业难”问题的重要举措。我国政府在社会化技能培训中扮演了主导的角色,既是培训的直接提供者,也是培训结果的评判者,却在行政权限、质量把关和监督监管方面存在明显的缺陷。因此,政府在社会化技能培训中应转变角色定位方向,从而有针对性地对其做好社会化技能培训。 展开更多
关键词 政府 社会化技能培训 合理定位
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Protective mechanism of testosterone on cognitive impairment in a rat model of Alzheimer's disease 被引量:10
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作者 Xu-Sheng Yan Zhan-Jun Yang +5 位作者 Jian-xin Jia Wei Song xin fang Zhi-Ping Cai Dong-Sheng Huo He Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第4期649-657,共9页
Cognitive dysfunction in Alzheimer's disease is strongly associated with a reduction in synaptic plasticity, which may be induced by oxidative stress. Testosterone is beneficial in learning and memory, although th... Cognitive dysfunction in Alzheimer's disease is strongly associated with a reduction in synaptic plasticity, which may be induced by oxidative stress. Testosterone is beneficial in learning and memory, although the underlying protective mechanism of testosterone on cognitive performance remains unclear. This study explored the protective mechanism of a subcutaneous injection of 0.75 mg testosterone on cognitive dysfunction induced by bilateral injections of amyloid beta 1–42 oligomers into the lateral ventricles of male rats. Morris water maze test results demonstrated that testosterone treatment remarkably reduced escape latency and path length in Alzheimer's disease rat models. During probe trials, testosterone administration significantly elevated the percentage of time spent in the target quadrant and the number of platform crossings. However, flutamide, an androgen receptor antagonist, inhibited the protective effect of testosterone on cognitive performance in Alzheimer's disease rat models. Nissl staining, immunohistochemistry, western blot assay, and enzyme-linked immunosorbent assay results showed that the number of intact hippocampal pyramidal cells, the dendritic spine density in the hippocampal CA1 region, the immune response and expression level of postsynaptic density protein 95 in the hippocampus, and the activities of superoxide dismutase and glutathione peroxidase were increased with testosterone treatment. In contrast, testosterone treatment reduced malondialdehyde levels. Flutamide inhibited the effects of testosterone on all of these indicators. Our data showed that the protective effect of testosterone on cognitive dysfunction in Alzheimer's disease is mediated via androgen receptors to scavenge free radicals, thereby enhancing synaptic plasticity. 展开更多
关键词 nerve REGENERATION Alzheimer’s disease TESTOSTERONE cognitive dysfunction synaptic plasticity free radicals MORRIS water maze androgen receptor FLUTAMIDE POSTSYNAPTIC density protein 95 amyloid beta 1–42 NEURODEGENERATIVE change neural REGENERATION
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Sevoflurane plays a reduced role in cognitive impairment compared with isoflurane: limited effect on fear memory retention 被引量:8
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作者 Ying Du Xiang-Dan Gong +3 位作者 xin fang fang xing Tian-Jiao Xia Xiao-Ping Gu 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第1期96-102,共7页
Isoflurane and sevoflurane are both inhalation anesthetics,but in clinical application,sevoflurane has been considered to be less suitable for long-term anesthesia because of its catabolic compounds and potential neph... Isoflurane and sevoflurane are both inhalation anesthetics,but in clinical application,sevoflurane has been considered to be less suitable for long-term anesthesia because of its catabolic compounds and potential nephrotoxicity.Nevertheless,recent studies have shown that these two inhalation anesthetics are similar in hepatorenal toxicity,cost,and long-term anesthetic effect.Moreover,sevoflurane possibly has less cognitive impact on young mice.In this study,C57BL/6 mice aged 8–10 weeks were exposed to 1.2%isoflurane or 2.4%sevoflurane for 6 hours.Cognitive function and memory were examined in young mice using the novel object recognition,contextual fear conditioning,and cued-fear extinction tests.Western blot assay was performed to detect expression levels of D1 dopamine receptor,catechol-O-methyltransferase,phospho-glycogen synthase kinase-3β,and total glycogen synthase kinase-3βin the hippocampus.Our results show that impaired performance was not detected in mice exposed to sevoflurane during the novel object recognition test.Contextual memory impairment in the fear conditioning test was shorter in the sevoflurane group than the isoflurane group.Long-term sevoflurane exposure did not affect memory consolidation,while isoflurane led to memory consolidation and reduced retention.Downregulation of hippocampal D1 dopamine receptors and phosphorylated glycogen synthase kinase-3β/total glycogen synthase kinase-3βand upregulation of catechol-O-methyltransferase may be associated with differing memory performance after exposure to isoflurane or sevoflurane.These results confirm that sevoflurane has less effect on cognitive impairment than isoflurane,which may be related to expression of D1 dopamine receptors and catechol-O-methyltransferase and phosphorylation of glycogen synthase kinase-3βin the hippocampus.This study was approved by the Institutional Animal Care and Use Committee,Nanjing University,China on November 20,2017(approval No.20171102). 展开更多
关键词 CATECHOL-O-METHYLTRANSFERASE cognitive impairment D1 dopamine receptors FEAR memory GLYCOGEN synthase kinase-3β ISOFLURANE NEUROTOXICOLOGY SEVOFLURANE
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Photoacoustic treatment mitigates cognitive dysfunction in a model of sleep-wake rhythm disturbance 被引量:5
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作者 fang xing xin fang +5 位作者 Xiang-Dan Gong xin Zhao Ying Du Zheng-Liang Ma Xiao-Ping Gu Tian-Jiao Xia 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第6期1094-1101,共8页
Sleep-wake rhythm disturbances,which are characterized by abnormal sleep timing or duration,are associated with cognitive dysfunction.Photoacoustic treatments including light and sound stimulation have been found to b... Sleep-wake rhythm disturbances,which are characterized by abnormal sleep timing or duration,are associated with cognitive dysfunction.Photoacoustic treatments including light and sound stimulation have been found to be effective in modulating sleep patterns and improving cognitive behavior in abnormal sleep-wake pattern experiments.In this study,we examined whether light and sound interventions could reduce sleep-wake pattern disturbances and memory deficits in a sleep rhythm disturbance model.We established a model of sleep rhythm disturbance in C57 BL/6 J mice via a sleep deprivation method involving manual cage tapping,cage jostling,and nest disturbance.We used a Mini Mitter radio transmitter device to monitor motor activity in the mice and fear conditioning tests to assess cognitive function.Our results indicated that an intervention in which the mice were exposed to blue light(40-Hz flickering frequency)for 1 hour during their subjective daytime significantly improved the 24-hour-acrophase shift and reduced the degree of memory deficit induced by sleep deprivation.However,interventions in which the mice were exposed to a 40-Hz blue light at offset time or subjective night time points,as well as 2 Hz-blue light at 3 intervention time points(subjective day time,subjective night time,and offset time points),had no positive effects on circadian rhythm shift or memory deficits.Additionally,a 2000-Hz sound intervention during subjective day time attenuated the24-hour-acrophase shift and memory decline,while 440-Hz and 4000-Hz sounds had no effect on circadian rhythms.Overall,these results demonstrate that photoacoustic treatment effectively corrected abnormal sleep-wake patterns and cognitive dysfunction associated with sleep-deprivation-induced disturbances in sleep-wake rhythm.All animal experiments were approved by the Experimental Animal Ethics Committee of Drum Tower Hospital Affiliated to the Medical College of Nanjing University,China(approval No.20171102)on November20,2017. 展开更多
关键词 CIRCADIAN RHYTHM cognitive impairment fear conditioning light INTERVENTION photoacoustic treatment RHYTHM DISTURBANCE RHYTHM shift sleep DEPRIVATION SLEEP-WAKE RHYTHM sound INTERVENTION
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