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1-MCP与MT联合处理对芒果保鲜效果的影响
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作者 袁芳 黎文卓 +2 位作者 王春艳 李丽 李志红 《现代食品科技》 CAS 北大核心 2024年第9期219-225,共7页
为探究1-甲基环丙烯(1-MCP)与褪黑素(MT)联合处理对芒果保鲜效果的影响,该研究用0.1 mg/L 1-MCP和0.2 mmol/L MT联合处理芒果后,于25℃贮藏10 d,每2 d取样测定相关指标。结果显示:1-MCP和MT联合处理可以延缓芒果果皮叶绿素降解和类胡萝... 为探究1-甲基环丙烯(1-MCP)与褪黑素(MT)联合处理对芒果保鲜效果的影响,该研究用0.1 mg/L 1-MCP和0.2 mmol/L MT联合处理芒果后,于25℃贮藏10 d,每2 d取样测定相关指标。结果显示:1-MCP和MT联合处理可以延缓芒果果皮叶绿素降解和类胡萝卜素含量升高,在贮藏第10天,处理组的果皮叶绿素为0.078 mg/g,是对照组的5.27倍;延缓了果肉L*值的下降和a*、b*值的升高,抑制原果胶降解和可溶性果胶含量的升高,贮藏第6天处理组的原果胶含量比对照高2.53倍,而可溶性果胶含量比对照低44.04%,同时在贮藏前期显著抑制了多聚半乳糖醛酸酶(PG)和纤维素酶(Cx)活性,降低了β-半乳糖苷酶(β-Gal)活性,并且维持了果肉更完整的细胞结构,但果肉类黄酮含量在贮藏中期显著低于对照。综上,1-MCP和MT联合处理保持了芒果良好的外观品质,延缓了细胞壁物质的降解,提高了货架期品质。 展开更多
关键词 1-MCP mt 芒果 果胶 细胞壁降解酶
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50mT静磁场试验装置的研制和性能验证
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作者 王中 赵文晖 郑拓 《上海计量测试》 2024年第5期19-21,共3页
为了满足有源植入式医疗器械标准中静磁场试验要求,研制了一款静磁场抗扰度试验装置。在输入电流约4.75 A条件下,该装置的磁通密度可以达到50 mT,且试验均匀域的磁通密度均匀性偏差达到2.8%。在0.055~50mT范围内,磁通密度的线性度达到了... 为了满足有源植入式医疗器械标准中静磁场试验要求,研制了一款静磁场抗扰度试验装置。在输入电流约4.75 A条件下,该装置的磁通密度可以达到50 mT,且试验均匀域的磁通密度均匀性偏差达到2.8%。在0.055~50mT范围内,磁通密度的线性度达到了0.6%。该装置还可以实现对电压、电流、时间、温度以及电磁场曝露等参数进行有效地监控。该研究为有源植入式医疗器械的静磁场抗扰度试验提供了理论和技术支撑。 展开更多
关键词 有源植入式医疗器械 静磁场抗扰度 50mt
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产教融合背景下基于MTS理论的金融知识学习及教学模式研究
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作者 闫举纲 牛心如 《财务管理研究》 2024年第9期150-157,共8页
在产教融合背景下,金融类课程的教学模式正向问题导向型转变。金融知识学习及教学通过产学协同,并匹配不同学生的学习特征和所要传授的知识特征,实现人才培养质量的提升。产教融合的模式中,混合型师资队伍建设是核心环节,通过案例研究,... 在产教融合背景下,金融类课程的教学模式正向问题导向型转变。金融知识学习及教学通过产学协同,并匹配不同学生的学习特征和所要传授的知识特征,实现人才培养质量的提升。产教融合的模式中,混合型师资队伍建设是核心环节,通过案例研究,基于多团队系统理论,探讨产教融合背景下如何构建由校内教师、行业专家和学生组成的多元化教学团队,并分析其运行机制和效果;同时,基于学习模型的教学支持与模式创新,结合学生学习特征,对主要教学方法进行体系化梳理,并优化教学方法,形成教学方案。 展开更多
关键词 多团队系统(mtS) 金融知识 学习模型 教学模式
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急性呼吸窘迫综合征患儿血清Melatonin、MIP-1α与NLRP3炎症小体和预后的关系分析
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作者 余娟 王俭 +2 位作者 杜华伟 杨学琴 杨婕 《国际检验医学杂志》 CAS 2024年第11期1331-1337,共7页
目的探讨急性呼吸窘迫综合征(ARDS)患儿血清褪黑素(Melatonin)、巨噬细胞炎性蛋白-1α(MIP-1α)与核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎症小体和预后的关系。方法选取2021年1月至2023年1月该院收治的ARDS患儿140例纳入ARDS组,另... 目的探讨急性呼吸窘迫综合征(ARDS)患儿血清褪黑素(Melatonin)、巨噬细胞炎性蛋白-1α(MIP-1α)与核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎症小体和预后的关系。方法选取2021年1月至2023年1月该院收治的ARDS患儿140例纳入ARDS组,另选取同期100例体检健康儿童纳入对照组。根据入院28 d临床结局将ARDS患儿分为死亡组29例和存活组111例。采用酶联免疫吸附试验检测血清Melatonin、MIP-1α、白细胞介素(IL)-1β、IL-18水平,实时荧光定量PCR检测NLRP3 mRNA、半胱氨酸蛋白酶-1(Caspase-1)mRNA水平。采用Pearson相关分析ARDS患儿血清Melatonin、MIP-1α水平与NLRP3炎症小体相关指标(NLRP3 mRNA、Caspase-1 mRNA、IL-1β、IL-18)的相关性。采用多因素Cox回归分析影响ARDS患儿预后的因素。根据ARDS患儿血清Melatonin、MIP-1α水平均值分为高/低血清Melatonin、MIP-1α组,Kaplan-Meier法绘制高/低血清Melatonin、MIP-1α水平ARDS患儿生存曲线。采用受试者工作特征(ROC)曲线分析血清Melatonin、MIP-1α对ARDS患儿死亡的预测价值。结果与对照组比较,ARDS组血清Melatonin水平降低,血清MIP-1α、IL-1β、IL-18和外周血单核细胞NLRP3 mRNA、Caspase-1 mRNA水平升高(P<0.05)。Pearson相关分析显示,ARDS患儿血清Melatonin水平与NLRP3 mRNA、Caspase-1 mRNA、IL-1β、IL-18均呈负相关(P<0.05),MIP-1α水平与NLRP3 mRNA、Caspase-1 mRNA、IL-1β、IL-18均呈正相关(P<0.05)。多因素Cox回归分析显示,急性生理学和慢性健康状况评价Ⅱ评分、NLRP3 mRNA、Caspase-1 mRNA、IL-1β、IL-18、MIP-1α为影响ARDS患儿预后的独立危险因素,Melatonin为独立保护因素(P<0.05)。Kaplan-Meier生存曲线分析显示,高血清Melatonin组28 d生存率高于低血清Melatonin组(P<0.05),高血清MIP-1α组28 d生存率低于低血清MIP-1α组(P<0.05)。ROC曲线分析显示,血清Melatonin、MIP-1α联合预测ARDS患儿死亡的曲线下面积为0.881(95%CI 0.816~0.930),大于血清Melatonin、MIP-1α单独预测的0.785(95%CI 0.708~0.850)、0.778(95%CI 0.700~0.844)。结论ARDS患儿血清Melatonin水平降低、MIP-1α水平升高,与NLRP3炎症小体和预后密切相关,联合检测血清Melatonin、MIP-1α水平对ARDS患儿预后具有较高的预测价值。 展开更多
关键词 急性呼吸窘迫综合征 褪黑素 巨噬细胞炎性蛋白-1Α 核苷酸结合寡聚化结构域样受体蛋白3
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Melatonin attenuates cisplatin-induced HepG2 cell death via the regulation of mTOR and ERCC1 expressions 被引量:2
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作者 Kangsadarn Bennukul Sucha Numkliang Vijittra Leardkamolkarn 《World Journal of Hepatology》 CAS 2014年第4期230-242,共13页
AIM:To elucidate the effects of melatonin on cisplatininduced hepatocellular carcinoma(HepG2) cell death and to identify potential cross-talk pathways.METHODS:Hepatocellular carcinoma HepG2 cells were treated with mel... AIM:To elucidate the effects of melatonin on cisplatininduced hepatocellular carcinoma(HepG2) cell death and to identify potential cross-talk pathways.METHODS:Hepatocellular carcinoma HepG2 cells were treated with melatonin and/or cisplatin for 24 to 48 h.Cell viability and the 50% cytotoxic concentration(CC50) were calculated by MTT assays.The effects and intracellular events induced by the selected concentrations of melatonin(1 mmol/L) and cisplatin(20 μmol/L) were investigated.Cell death and survival detection were primarily evaluated using a fluorescence microscope to assess 4',6 diamideno-2-phenylindol DNA staining and acridine orange lysosome staining and then further analyzed with immunocytochemistry using an anti-LC3 antibody.The potential molecularresponses mediated by melatonin against cisplatin after the combined treatment were investigated by reverse transcription-polymerase chains reaction and Western blot analyses of the genes and proteins associated with cell survival and death.A cell cycle analysis was performed using a flow cytometry assay.RESULTS:Melatonin had a concentration-dependent effect on HepG2 cell viability.At 1 mmol/L,melatonin significantly increased the cell viability percentage and decreased reactive oxygen species production due to cisplatin.Melatonin reduced cisplatin-induced cell death,decreasing phosphorylated p53 apoptotic protein,cleaved caspase 3 and Bax levels but increasing anti-apoptotic Bcl-2 gene and protein expression.When combined with cisplatin,melatonin induced S phase(DNA synthesis) cell cycle arrest and promoted autophagic events in HepG2 cells.Melatonin also had a concentration-dependent effect on Beclin-1 and its autophagic regulator mammalian target of rapamycin(mTOR) as well as the DNA excision repair cross complementary 1(ERCC1) protein.The expression levels of these proteins were altered in HepG2 cells during cisplatin or melatonin treatment alone.In the combination treatment,melatonin reversed the effects of cisplatin by suppressing the over-expression of mTOR and ERCC 1 and enhancing the expression levels of Beclin-1 and microtubule-associated protein-light chain3-Ⅱ,leading to intracellular autophagosome progression.CONCLUSION:Melatonin attenuated cisplatin-induced cell death in HepG2 cells via a counter-balance between the roles of apoptotic- and autophagy-related proteins. 展开更多
关键词 melatonin CISPLATIN Hepatocellular carcinoma EXCISION repair cross complementary 1 MAMMALIAN target of RAPAMYCIN Autophagy
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基于VTI介质海洋CSEM和MT数据联合反演的黄海海相残留盆地深部结构研究
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作者 罗鸣 裴建新 +1 位作者 段双敏 吴志强 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第5期1853-1865,共13页
黄海海相残留盆地因其地层结构和深部地质构造的复杂性,一直是我国海洋地球科学的一项研究重点,虽然针对该研究区已开展了一系列的地球物理调查,但由于高速碳酸盐岩层对地震波存在着一定的屏蔽作用,致使该海域深部地震资料品质受到较大... 黄海海相残留盆地因其地层结构和深部地质构造的复杂性,一直是我国海洋地球科学的一项研究重点,虽然针对该研究区已开展了一系列的地球物理调查,但由于高速碳酸盐岩层对地震波存在着一定的屏蔽作用,致使该海域深部地震资料品质受到较大影响.海洋电磁法不受高速屏蔽层影响,有利于获得高速屏蔽层内部及其下方的深部结构信息.海洋可控源电磁法(Controlled source electromagnetic method,CSEM)和海洋大地电磁测深(Magnetotelleric,MT)能够提供海底电性结构的互补信息,较于单一的电磁方法,二者联合可获得更为准确的海底电性分布.本文提出了基于乘积目标函数的层状垂直各向异性(Vertical anisotropic,VTI)介质海洋可控源电磁和大地电磁资料联合反演方法,该方法在迭代过程中根据数据的拟合情况自适应调整CSEM和MT数据的权重和正则化因子的权重,反演参数包括海底介质的横向电阻率、垂向电阻率和地层厚度.以南黄海地质地球物理资料为例,建立浅水环境地电模型,并结合浅水环境的高噪声背景特点进行合成数据模型测试及分析.将本文所提出算法应用于理论模型合成数据和南黄海实测资料反演,结果表明,较于单独的海洋CSEM和MT反演,联合反演方法能够较准确地重构海底地层的电性分布,提高对海底地层各向异性电阻率的分辨能力. 展开更多
关键词 电阻率各向异性 联合反演 CSEM mt 南黄海
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Melatonin Enhances Object Recognition Memory through Melatonin MT1 and MT2 Receptor-Mediated and Non-Receptor-Mediated Mechanisms in Male Mice
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作者 Masahiro Sano Hikaru Iwashita +1 位作者 Atsuhiko Hattori Atsuhiko Chiba 《Journal of Behavioral and Brain Science》 CAS 2022年第12期640-657,共18页
Melatonin (MEL) has been reported to have acute enhancing effects on some aspects of cognition. Recently, we revealed that N1-acetyl-5-methoxyquinuramine (AMK), a brain metabolite of MEL, is much more potent than MEL ... Melatonin (MEL) has been reported to have acute enhancing effects on some aspects of cognition. Recently, we revealed that N1-acetyl-5-methoxyquinuramine (AMK), a brain metabolite of MEL, is much more potent than MEL in converting short-term memory (STM) to long-term memory (LTM) with a single administration immediately after the acquisition trial of the novel object recognition (NOR) task. These data suggest that the memory-enhancing effects of MEL may be mediated by mechanisms independent of the activation of MEL MT1 and MT2 receptors. In the present study, we examined the contribution of MT1 and MT2 receptor-mediated and non-receptor-mediated mechanisms to the acute memory-enhancing effects of MEL using NOR task. Mice were administered with either MEL, AMK, or a highly selective MT1/MT2 receptor agonist ramelteon (RAM) immediately after the acquisition trial and the effects of varying doses of these drugs on both STM and LTM performance were compared. We found that both AMK and RAM were more potent than MEL in both facilitating STM and promoting LTM formation. We also found that pretreatment with luzindole, a MT1/MT2 receptor antagonist, markedly suppressed only the effects of RAM. These results suggest that acutely administered MEL enhances NOR memory through both MT1 and MT2 receptor-mediated and non-receptor-mediated mechanisms. 展开更多
关键词 melatonin N1-Acetyl-5-Methoxykynuramine Ramelteon Novel Object Recognition Memory melatonin Receptors
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ACAT1和MTNR1B基因多态性与非酒精性脂肪性肝病易感性的关系 被引量:1
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作者 马磊 胡欣欣 +4 位作者 赵波 万强 周林 赵真真 辛永宁 《临床肝胆病杂志》 CAS 北大核心 2024年第4期700-705,共6页
目的本研究拟探讨乙酰辅酶A乙酰转移酶1(ACAT1)和褪黑激素受体1B(MTNR1B)基因多态性与非酒精性脂肪性肝病(NAFLD)疾病易感性的关系。方法本研究共纳入2020年12月—2022年6月就诊于青岛市市立医院的健康体检者164例、NAFLD患者228例。采... 目的本研究拟探讨乙酰辅酶A乙酰转移酶1(ACAT1)和褪黑激素受体1B(MTNR1B)基因多态性与非酒精性脂肪性肝病(NAFLD)疾病易感性的关系。方法本研究共纳入2020年12月—2022年6月就诊于青岛市市立医院的健康体检者164例、NAFLD患者228例。采用PCR及测序的方法对ACAT1 rs1044925、rs1157651和MTNR1B rs10830963基因多态性进行基因分型,并采集空腹静脉血进行生化检测。符合正态分布的计量资料两组间比较采用成组t检验;非正态分布的计量资料两组间比较采用Mann-Whitney U非参数检验;计数资料两组间比较采用χ2检验。结果ACAT1 rs1044925、rs1157651和MTNR1B rs10830963基因型分布在NAFLD及健康对照组间无统计学差异(P值均>0.05),ACAT1 rs1044925 AA基因型携带者的LDL水平明显高于C等位基因携带者(Z=−2.08,P=0.04),MTNR1B rs10830963 G等位基因携带者空腹血糖水平明显高于CC基因型携带者(Z=−3.01,P<0.01)。结论ACAT1 rs1044925、rs1157651和MTNR1B rs10830963多态性与NAFLD易感性无明显相关,ACAT1 rs1044925和MTNR1B rs10830963位点分别与LDL和空腹血糖水平有关。 展开更多
关键词 非酒精性脂肪性肝病 乙酰CoA C-乙酰转移酶 受体 褪黑激素
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Melatonin delays leaf senescence in pak choi(Brassica rapa subsp.chinensis)by regulating biosynthesis of the second messenger cGMP 被引量:1
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作者 Xuesong Liu Ronghui An +3 位作者 Guofeng Li Shufen Luo Huali Hu Pengxia Li 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第1期145-155,共11页
Melatonin(MT)is a low molecular weight compound with multiple biological functions in plants.It is known to delay leaf senescence in various species.However,no data are available on the MT signaling pathway in posthar... Melatonin(MT)is a low molecular weight compound with multiple biological functions in plants.It is known to delay leaf senescence in various species.However,no data are available on the MT signaling pathway in postharvest vegetables.This study demonstrates that MT increases cGMP concentration and the expression of the cGMP synthesis gene BcGC1 in pak choi.The c GMP inhibitor LY83583 destroys effect of MT delaying the leaf senescence.LY83583 also prevents MT treatment from reducing the expression of chlorophyll metabolism-related genes(BcNYC1,BcNOL,BcPPH1/2,BcSGR1/2,and BcPAO)and senescence genes(BcSAG12 and BcSAG21).It also inhibits MT from reducing the activity of the key chlorophyll catabolism enzymes Mg-dechelatase,pheophytinase,and pheide a oxygenase.Thus,the ability of MT to maintain high levels of chlorophyll metabolites is also destroyed.The Arabidopsis c GMP synthetic gene mutant atgc1 was used to confirm that delayed leaf senescence caused by MT is mediated,at least in part,by the second messenger c GMP. 展开更多
关键词 Pak choi melatonin CGMP Chlorophyll degradation Senescence
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Exogenous melatonin improves cotton yield under drought stress by enhancing root development and reducing root damage 被引量:1
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作者 Lingxiao Zhu Hongchun Sun +8 位作者 Ranran Wang Congcong Guo Liantao Liu Yongjiang Zhang Ke Zhang Zhiying Bai Anchang Li Jiehua Zhu Cundong Li 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第10期3387-3405,共19页
The exogenous application of melatonin by the root drenching method is an effective way to improve crop drought resistance.However,the optimal concentration of melatonin by root drenching and the physiological mechani... The exogenous application of melatonin by the root drenching method is an effective way to improve crop drought resistance.However,the optimal concentration of melatonin by root drenching and the physiological mechanisms underlying melatonin-induced drought tolerance in cotton(Gossypium hirsutum L.)roots remain elusive.This study determined the optimal concentration of melatonin by root drenching and explored the protective effects of melatonin on cotton roots.The results showed that 50μmol L-1 melatonin was optimal and significantly mitigated the inhibitory effect of drought on cotton seedling growth.Exogenous melatonin promoted root development in drought-stressed cotton plants by remarkably increasing the root length,projected area,surface area,volume,diameter,and biomass.Melatonin also mitigated the drought-weakened photosynthetic capacity of cotton and regulated the endogenous hormone contents by regulating the relative expression levels of hormone-synthesis genes under drought stress.Melatonin-treated cotton seedlings maintained optimal enzymatic and non-enzymatic antioxidant capacities,and produced relatively lower levels of reactive oxygen species and malondialdehyde,thus reducing the drought stress damage to cotton roots(such as mitochondrial damage).Moreover,melatonin alleviated the yield and fiber length declines caused by drought stress.Taken together,these findings show that root drenching with exogenous melatonin increases the cotton yield by enhancing root development and reducing the root damage induced by drought stress.In summary,these results provide a foundation for the application of melatonin in the field by the root drenching method. 展开更多
关键词 COTTON DROUGHT melatonin root morphology root physiology yield
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Melatonin improves synapse development by PI3K/Akt signaling in a mouse model of autism spectrum disorder 被引量:4
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作者 Luyi Wang Man Xu +8 位作者 Yan Wang Feifei Wang Jing Deng Xiaoya Wang Yu Zhao Ailing Liao Feng Yang Shali Wang Yingbo Li 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1618-1624,共7页
Autism spectrum disorders are a group of neurodevelopmental disorders involving more than 1100 genes,including Ctnnd2 as a candidate gene.Ctnnd2knockout mice,serving as an animal model of autis m,have been demonstrate... Autism spectrum disorders are a group of neurodevelopmental disorders involving more than 1100 genes,including Ctnnd2 as a candidate gene.Ctnnd2knockout mice,serving as an animal model of autis m,have been demonstrated to exhibit decreased density of dendritic spines.The role of melatonin,as a neuro hormone capable of effectively alleviating social interaction deficits and regulating the development of dendritic spines,in Ctnnd2 deletion-induced nerve injury remains unclea r.In the present study,we discove red that the deletion of exon 2 of the Ctnnd2 gene was linked to social interaction deficits,spine loss,impaired inhibitory neurons,and suppressed phosphatidylinositol-3-kinase(PI3K)/protein kinase B(Akt) signal pathway in the prefrontal cortex.Our findings demonstrated that the long-term oral administration of melatonin for 28 days effectively alleviated the aforementioned abnormalities in Ctnnd2 gene-knockout mice.Furthermore,the administration of melatonin in the prefro ntal cortex was found to improve synaptic function and activate the PI3K/Akt signal pathway in this region.The pharmacological blockade of the PI3K/Akt signal pathway with a PI3K/Akt inhibitor,wo rtmannin,and melatonin receptor antagonists,luzindole and 4-phenyl-2-propionamidotetralin,prevented the melatonin-induced enhancement of GABAergic synaptic function.These findings suggest that melatonin treatment can ameliorate GABAe rgic synaptic function by activating the PI3K/Akt signal pathway,which may contribute to the improvement of dendritic spine abnormalities in autism spectrum disorders. 展开更多
关键词 AUTISM Ctnnd2 deletion GABAergic neurons melatonin PI3K/Akt signal pathway prefrontal cortex social behavior spine density synaptic-associated proteins
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Exercise-with-melatonin therapy improves sleep disorder and motor dysfunction in a rat model of ischemic stroke 被引量:1
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作者 Haitao Zhao Tong Zhang +2 位作者 Haojie Zhang Yunlei Wang Lingna Cheng 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第6期1336-1343,共8页
Exercise-with-melatonin therapy has complementary and synergistic effects on spinal cord injury and Alzheimer's disease,but its effect on stroke is still poorly understood.In this study,we established a rat model ... Exercise-with-melatonin therapy has complementary and synergistic effects on spinal cord injury and Alzheimer's disease,but its effect on stroke is still poorly understood.In this study,we established a rat model of ischemic stroke by occluding the middle cerebral artery for 60 minutes.We treated the rats with exercise and melatonin therapy for 7 consecutive days.Results showed that exercise-with-melatonin therapy significantly prolonged sleep duration in the model rats,increased delta power values,and regularized delta power rhythm.Additionally,exercise-with-melatonin therapy improved coordination,endurance,and grip strength,as well as learning and memory abilities.At the same time,it led to higher hippocampal CA1 neuron activity and postsynaptic density thickness and lower expression of glutamate receptor 2 than did exercise or melatonin therapy alone.These findings suggest that exercise-withmelatonin therapy can alleviate sleep disorder and motor dysfunction by increasing glutamate receptor 2 protein expression and regulating hippocampal CA1 synaptic plasticity. 展开更多
关键词 EXERCISE glutamate receptor 2 HIPPOCAMPUS ischemic stroke learning melatonin memory sleep disorder synaptic plasticity
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IGF1、CoQ10、MT联合添加缓解热应激对牛IVF囊胚的影响
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作者 张航 张培培 +6 位作者 杨柏高 冯肖艺 牛一凡 余洲 曹建华 万鹏程 赵学明 《畜牧兽医学报》 CAS CSCD 北大核心 2024年第6期2474-2485,共12页
旨在探明胰岛素样生长因子1(insulin-like growth factors 1,IGF1)、辅酶Q10(coenzyme Q10,CoQ10)及褪黑素(melatonin, MT)联合添加对牛卵母细胞和胚胎发育以及热应激囊胚的影响。本研究于屠宰场采集牛离体卵巢,于实验室抽取卵丘卵母细... 旨在探明胰岛素样生长因子1(insulin-like growth factors 1,IGF1)、辅酶Q10(coenzyme Q10,CoQ10)及褪黑素(melatonin, MT)联合添加对牛卵母细胞和胚胎发育以及热应激囊胚的影响。本研究于屠宰场采集牛离体卵巢,于实验室抽取卵丘卵母细胞复合体(cumulus-oocyte complexes, COCs),在牛卵母细胞体外成熟(in vitro maturation, IVM)液及牛胚胎体外培养(in vitro culture, IVC)液中添加IGF1、CoQ10及MT,检测各添加方式对牛卵母细胞发育能力、牛卵母细胞活性氧(reactive oxygen species, ROS)水平及线粒体膜电位(mitochondrial membrane potential,ΔΨm)的影响;在囊胚期施加41℃热应激,检测热应激及联合添加对牛IVF囊胚发育能力及凋亡水平的影响,并利用qRT-PCR检测囊胚中胚胎质量相关基因mRNA表达水平。各组试验均重复3次。结果表明,与未添加组(CT-0组)相比,联合添加IGF1、CoQ10及MT组(ICM组)卵母细胞成熟率((90.40±2.06)%vs.(65.41±0.63)%)、卵裂率((93.33±1.96)%vs.(59.77±2.93)%)及囊胚率((51.43±5.34)%vs.(26.92±3.24)%)均显著提高(P<0.05);ICM组牛卵母细胞ROS水平显著降低;ΔΨm显著提高(P<0.05)。与热应激组(HS组)相比,联合添加IGF1、CoQ10及MT(ICM+HS组)显著提高了囊胚扩张率((62.00±2.97)%vs.(30.77±8.66)%,P<0.05),抑制了热应激囊胚细胞凋亡,并提高了IGFBP3、ATP1A1、DSC2及IFNT2的mRNA表达水平(P<0.05)。综上表明,联合添加IGF1、CoQ10及MT有效提高牛卵母细胞发育能力,降低ROS水平,提高ΔΨm。热应激降低牛囊胚扩张率,促进牛囊胚细胞凋亡,影响囊胚质量,而联合添加IGF1、CoQ10及MT缓解了热应激损伤。 展开更多
关键词 IGF1 CoQ10 褪黑素 热应激 奶牛 胚胎
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基于调车工况的MT-2缓冲器容量需求仿真分析
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作者 孙林平 杨忠良 +2 位作者 马卫华 罗世辉 王波 《振动与冲击》 EI CSCD 北大核心 2024年第13期210-216,共7页
为了分析MT-2缓冲器在调车连挂作业时的容量需求问题,基于摩擦式缓冲器非线性力学特性及车辆调车冲击受力特点,建立了铁道货车纵向冲击动力学模型,对调车过程中不同车辆质量、不同速度、不同编组方式及不同车体刚度等工况下MT-2缓冲器... 为了分析MT-2缓冲器在调车连挂作业时的容量需求问题,基于摩擦式缓冲器非线性力学特性及车辆调车冲击受力特点,建立了铁道货车纵向冲击动力学模型,对调车过程中不同车辆质量、不同速度、不同编组方式及不同车体刚度等工况下MT-2缓冲器容量需求进行了分析。研究结果表明:缓冲器做功与车辆质量和连挂速度的平方成正比,冲击车和被冲击车数量都大于2辆时冲击面缓冲器的容量需求将与车辆数量无关。对同时考虑质量、速度、编组方式、车体刚度的缓冲器容量需求值进行了函数拟合,完成了比例系数κ、μ和λ的求解;不同车辆数量之间冲击时,不同车钩号的缓冲器做功值大小不一,在冲击面车钩号的缓冲器做功值均为最大,沿着冲击面前、后的车钩号逐渐递减,调车冲击时计算容量需求值时应不考虑车体刚度,以重车冲击重车模式时冲击面的缓冲器容量需求为准。 展开更多
关键词 调车冲击 mt-2缓冲器 车钩力 容量需求 做功值
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ASMT介导运动抗抑郁的炎症作用机制
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作者 黄卓淳 漆正堂 刘微娜 《武汉体育学院学报》 CSSCI 北大核心 2024年第9期66-74,共9页
目的:探究N-乙酰基-5-羟色胺-甲基转移酶(ASMT)基因敲除和运动对小鼠抑郁行为及神经炎症和肠道菌群的影响。方法:将6-7周龄雌性野生型小鼠和ASMT基因敲除小鼠随机分为安静组和运动组。12周的有氧跑台训练结束后,所有小鼠进行行为学测试... 目的:探究N-乙酰基-5-羟色胺-甲基转移酶(ASMT)基因敲除和运动对小鼠抑郁行为及神经炎症和肠道菌群的影响。方法:将6-7周龄雌性野生型小鼠和ASMT基因敲除小鼠随机分为安静组和运动组。12周的有氧跑台训练结束后,所有小鼠进行行为学测试,训练期间收集小鼠粪便,然后将小鼠麻醉处死后取前额皮质和下丘脑。采用RT-PCR检测前额皮质促炎与抗炎因子和TLR4/NF-κB信号通路相关基因的表达水平;采用Western blotting检测下丘脑TLR4、p-IKBα、p65、p-p65和IL-Iβ的蛋白水平;采用16SrRNA基因测序检测小鼠运动干预第四周及第八周的粪便样本中菌群组成和丰度。结果:ASMT基因敲除会诱发小鼠的抑郁行为,运动可以有效缓解小鼠的抑郁行为。ASMT基因敲除后促炎因子水平和TLR4/NF-κB信号通路表达水平增加。肠道菌群16SrRNA基因测序结果显示ASMT基因敲除后α多样性及β多样性发生改变,细菌群落相对丰度有显著差异,持续的运动干预可以减少炎症从而调节肠道菌群稳态。结论:ASMT基因敲除可导致小鼠的抑郁行为,与TLR4/NF-κB信号通路影响神经炎症及肠道菌群有关,运动可以通过调节“微生物-肠-炎症-脑”轴改善肠道菌群紊乱进而缓解ASMT基因敲除导致的抑郁行为。 展开更多
关键词 抑郁 褪黑素 N-乙酰基-5-羟色胺-甲基转移酶(ASmt) 运动 神经炎症 肠道菌群
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基于MT-CNN的矿井带式输送机输煤量检测技术 被引量:3
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作者 张克亮 《中国矿业》 北大核心 2024年第6期137-142,共6页
为实现矿井带式输送机输煤量检测的信息化、智能化,提出基于MT-CNN的矿井带式输送机输煤量检测技术。为了全面提升输煤量检测技术,从而提高矿井效益,选取了多任务卷积神经网络(MT-CNN)对检测目标进行多核心识别检测,优化了图像直线信息... 为实现矿井带式输送机输煤量检测的信息化、智能化,提出基于MT-CNN的矿井带式输送机输煤量检测技术。为了全面提升输煤量检测技术,从而提高矿井效益,选取了多任务卷积神经网络(MT-CNN)对检测目标进行多核心识别检测,优化了图像直线信息和边缘信息的提取效率,构建了良好的网络层次结构,优化了信息连接通道,从而全面提高图像识别分析和数据检测处理的效果。通过MT-CNN技术对输煤量的轮廓形态和荷载状态进行分析运算,经过图像样本数据训练获取矿井带式输送机输煤量的相关数据。研究结果表明,该技术能够有效提高输煤量图像识别的真实性,而检测时间缩短49%,计算结果准确率提高到98%,有效提高了输煤量检测的效率和准确度,具有较好的应用性能和良好的使用效果。加强矿井带式输送机的输煤量检测,可以为后续研究提供依据,很大程度上推动了相关技术发展,实现矿井信息化、智能化、现代化发展。 展开更多
关键词 mt-CNN 卷积神经网络 带式输送机 激光测距 输煤量检测
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5G集约化VoLTE短信网关MT成功率提升方案研究
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作者 刘晓婷 王玉玲 +1 位作者 刘晓鸣 刘晓军 《山东通信技术》 2024年第3期14-17,共4页
导致集约化VoLTE短信网关上线后MT成功率较割接前下降的三种主要原因,包括VoLTE网关对短信中心长会话保持参数识别错误、多业务处理机之间缺乏有效的协同机制、对MT短信ENUMDNS查询量过大。实施针对性改进措施后,成功率得到了显著提升。
关键词 VoLTE短信 mt短信 业务处理机
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Seasonal variation of melatonin secretion across various segments of the gastrointestinal tract in rats
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作者 Yuxin Zhang Xuejie Huang +6 位作者 Yilu Peng Yuxi Liang Wenjing Zhang Yadong Cui Xiaoying Xu Xiuhua Hu Xiaoyan Liu 《Journal of Traditional Chinese Medical Sciences》 CAS 2024年第3期275-282,共8页
Objective:To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune regulation.Methods: Sixty Sprague-Dawley rats w... Objective:To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune regulation.Methods: Sixty Sprague-Dawley rats were divided into control and model groups,and the pineal gland was removed in the model group.Stomach,jejunum,ileum,and colon tissues were obtained during the spring equinox,summer solstice,beginning of autumn,autumn equinox,and winter solstice.The levels of MT,MT receptors(MR),arylalkylamine N-acetyltransferase(AANAT),hydroxyindole-O-methyltransferase(HIOMT),interleukin-2(IL-2),and interleukin-10(IL-10)in the GIT were measured using enzyme-linked immunosorbent assay.Results: Except for the stomach,the jejunum,ileum,and the colon showed seasonal tendencies in MT secretion.In the control group,MT secretion in the jejunum and ileum was the highest in the long summer,and colonic MT secretion was the highest in winter.In the model group,MT levels in the colon were highest in the summer.The seasonal rhythms of the MR,AANAT,HIOMT,IL-2,and IL-10 in the colon were roughly similar to those of MT,and changed accordingly after pinealectomy.Conclusions: Gastrointestinal MT secretion is related to seasonal changes,and MT secretion in each intestinal segment is influenced by different seasons.The biological effects of MT in the gut are inextricably linked to the mediation of MR,and a hormone-receptor linkage exists between MT and MR.The effect of seasonal changes on the gastrointestinal immune system may be mediated through the regulation of seasonal secretion of MT. 展开更多
关键词 melatonin Seasonal variations Pineal gland Gastrointestinal tract melatonin receptors
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Melatonin and dopamine alleviate waterlogging stress in apples by recruiting beneficial endophytes to enhance physiological resilience
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作者 Yang Cao Peihua Du +5 位作者 Yuwei Shang Jiahao Ji Leiqing Tan Xue Zhang Jizhong Xu Bowen Liang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第7期2270-2291,共22页
Melatonin and dopamine can potentially prevent waterlogging stress in apples.The current study investigated the mechanism by which melatonin and dopamine alleviate apple waterlogging stress.This study demonstrated tha... Melatonin and dopamine can potentially prevent waterlogging stress in apples.The current study investigated the mechanism by which melatonin and dopamine alleviate apple waterlogging stress.This study demonstrated that melatonin and dopamine alleviated waterlogging by removing reactive oxygen species(ROS),and that the nitric oxide(NO)content and nitrate reductase(NR)activity were significantly correlated.Melatonin and dopamine were also found to recruit different candidate beneficial endophytes(melatonin:Novosphingobium,Propionivibrio,and Cellvibrio;dopamine:Hydrogenophaga,Simplicispira,Methyloversatilis,Candidatus_Kaiserbacteria,and Humicola),and these endophytes were significantly and positively correlated with plant growth.Network analyses showed that melatonin and dopamine significantly affected the endophytic bacterial and fungal communities under waterlogging stress.The metabolomic results showed that melatonin and dopamine led to waterlogging resistance by upregulating the abundance of beneficial substances such as amino acids,flavonoids,coumarins,and organic acids.In addition,melatonin and dopamine regulated the physicochemical properties of the soil,which altered the endophyte community and affected plant growth.The co-occurrence network demonstrated close and complex relationships among endophytes,metabolites,soil,and the plants.Our results demonstrate that melatonin and dopamine alleviate waterlogging stress in apples by recruiting beneficial endophytes to enhance physiological resilience.This study provides new insights into how melatonin and dopamine alleviate stress and a theoretical basis for synergistic beneficial microbial resistance to waterlogging stress. 展开更多
关键词 DOPAMINE ENDOPHYTES Malus hupehensis melatonin metabolomics WATERLOGGING
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基于MT7620A的智慧监控网关设计
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作者 黄赟 朱金荣 +2 位作者 武忠鑫 金廷宇 李佳颖 《物联网技术》 2024年第5期52-56,共5页
针对网络摄像机不具备远程监控能力的问题,基于MT7620A设计了一种支持远程监控的智慧网关。网关使用MT7620A作为主控芯片,搭载OpenWrt系统。通过创建ONVIF客户端与同一局域网中支持ONVIF协议的监控设备进行通信,实现设备发现、信息获取... 针对网络摄像机不具备远程监控能力的问题,基于MT7620A设计了一种支持远程监控的智慧网关。网关使用MT7620A作为主控芯片,搭载OpenWrt系统。通过创建ONVIF客户端与同一局域网中支持ONVIF协议的监控设备进行通信,实现设备发现、信息获取、云台控制和视频流读取等功能;网关与云平台通过MQTT协议实现信令交互,云平台可以向网关发送设备管理、云台控制和视频流读取等命令;网关通过数据处理模块对命令进行解析和协议转换,实现对设备的管理,以及对监控设备云台的控制和视频流读取。网关在使用FFMPEG接口获取视频流之后,通过Socket TCP与云平台建立连接并发送视频流,保证视频流远程传输的稳定可靠。网关配有4G通信模块,避免了接入互联网受到有线网络通信的限制,双重通信方式更加有效地保障了网络传输。测试结果表明,所设计的网关能够支持云平台实现对设备的远程监控和控制。 展开更多
关键词 智慧监控网关 mt7620A OpenWrt ONVIF FFMPEG MQTT Socket TCP 4G模块
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