检索结果-南通市图书馆

Exploring the N-terminus region： Synthesis, bioactivity and 3D-QSAR of allatostatin analogs as novel insect growth regulators

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2018年第9期29卷 1375-1378页

作者： Meizi Wang li Zhang Xianwei Wang Yun ling Xiaoqing Wu xinlu li Yiduo Mi Xinling Yang Deportment of Applied Chemistry College of Science China Agricultural University Beijing 100193 China

Allatostatins （ASTs）, a family of insect neuropeptide, can inhibit juvenile hormone （JH） biosynthesis by the corpora allata （CA） in Diploptera punctata, and therefore be regarded as potential leads for the discovery of new insect growth regulators （1GRs）. But several shortcomings, such as their sensitivity to peptidases and high cost, impeded their practical application in pest management. In order to discover new IGRs, one AST analog B1 possessing non-peptide group was discovered with high ability to inhibit JH biosynthesis in vitro （IC50： 0.09 μmol/L） in our previous studies. In the present work, two series of B1 analogs with different substituents on the N-terminus region were designed and synthesized. The result suggested that benzene showed better activity than other heterocycles, and the para-substitution on the benzene was beneficial for activity. Moreover, analogs with logP value over 2.0 exhibited good activity, which indicated the hydrophobicity is important to the bioactivity. Three dimension quantitative structure-activity relationship （3D-QSAR） studies were performed to highlight the structural require- ments of ASTanalogs, which demonstrated introduction of bulkier substituents on the N-terminus would increase the activity. Analog Ⅱ12 （IC50： 0.08 μmol/L） exhibited similar inhibitory activity to the lead B1, but its synthetic route was simpler than B1. Therefore, Ⅱ12 could be used as a new lead compound for the discovery eco-friendly IGRs.

关键词： Allatostatins Juvenile hormone IGRs AST analogs Synthesis 3D-QSAR

The effects of Age of Acquisition on an L2 learner’s Ultimate Attainment

在线全文

学校读者我要写书评

暂无评论

Journal of Contemporary Educational Research 2020年第5期4卷 23-26页

作者： xinlu li University of New South Wales Australia Changsha University of Science and Technology China

This paper focuses on generalizing different theories towards the age effect on the ultimate attainment of second language learners since it has long been a controversial topic in researchers’*** this paper,it gives evidences on cases in favor of the Critical Period Hypothesis,which claimed the loss of language learning ability after puberty and presents counter-evidences on the successful acquisition of second language in adult *** has reached into a conclusion that consists the viewpoint drawn on previous analysis and confirmed the possibility in ultimate second language attainment for late learners.

关键词： Ultimate Attainment Critical Period Second Language Acquisition

DMT1 overexpression exacerbates Aβ oligomer-induced cell damage

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

DMT1 overexpression exacerbates Aβ oligomer-induced cell da...

Magnetic Switching Dynamics and Tunnel Magnetoresistance Effect Based on Spin-Splitting Noncollinear Antiferromagnet Mn_(3)Pt

中国解剖学会2021年年会

作者： Cheng Xiaofeng li xinlu lingeng Tong liutong Zhengwei Department of Histology and Embryology School of Basic Medical SciencesChina Medical University Department of Neurology Liaoning Provincial People’s Hospital

This study aims to reveal the role of metal ion transporter DMT1 in neurotoxicity induced by Aβ *** exposed SH-SY5Y cells (S-DMT1) stably overexpressing the DMT1gene and SH-SY5Y cells (SGFP) overexpressing empty green fluorescent protein to Aβ ***8 and Hoechst 33258 were used to detect the cell death rate and apoptotic rate.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第4期41卷 132-138页

作者：朱蒙董建艇李新录郑凡星周晔吴琨张佳 School of Physics and Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074China

In comparison to ferromagnets,antiferromagnets are believed to have superior advantages for applications in next-generation magnetic storage devices,including fast spin dynamics,vanishing stray fields and robust against external magnetic field,***,unlike ferromagnetic orders,which could be detected through tunneling magnetoresistance effect in magnetic tunnel junctions,the antiferromagnetic order(i.e.,Néel vector)cannot be effectively detected by the similar mechanism due to the spin degeneracy of conventional *** discovered spin-splitting noncollinear antiferromagnets,such as Mn_(3)Pt with momentum-dependent spin polarization due to their special magnetic space group,make it possible to achieve remarkable tunneling magnetoresistance effects in noncollinear antiferromagnetic tunnel *** first-principles calculations,we demonstrate that the tunneling magnetoresistance ratio can reach more than 800% in Mn_(3)Pt/perovskite oxides/Mn_(3)Pt antiferromagnetic tunnel *** also reveal the switching dynamics of Mn_(3)Pt thin film under magnetic fields using atomistic spin dynamic *** study provides a reliable method for detecting Néel vector of noncollinear antiferromagnets through the tunnel magnetoresistance effect and may pave its way for potential applications in antiferromagnetic memory devices.

关键词： tunneling magnetoresistance momentum

Synthesis, bioactivity and 3D-QSAR of allatostatin analogs as novel insect growth regulators

在线全文

学校读者我要写书评

暂无评论

Synthesis, bioactivity and 3D-QSAR of allatostatin analogs a...

基于卷积自编码器分块学习的视频异常事件检测与定位

第十届全国化学生物学学术会议

作者： Meizi Wang li Zhang Xianwei Wang Yun ling Xiaoqing Wu xinlu li YiduoMi Xinling Yang Department of Applied Chemistry College of ScienceChina Agricultural University

Allatostatins(ASTs), a family of insect neuropeptide, can inhibit juvenile hormone(JH) biosynthesis by the corpora allata(CA) in Diploptera punctata, and therefore be regarded as the potential leads for the discovery of new Insect Growth Regulators(IGRs). But several shortcomings, such as their sensitivity to peptidases and high cost, impeded their practical application in pest management. In order to discover new IGRs, one AST analog B1 possessing non-peptide group was discovered with high ability to inhibit JH biosynthesis in vitro(IC:0.09μM) in our previous studies. In the present work, two series of B1 analogs with different substituents on the N-terminus region were designed and synthesized. The result suggested the para-substitution on benzene was beneficial for activity. Moreover, analogs with LogP value over 2.0 exhibited good activity, which indicated the hydrophobicity is important to the bioactivity. Three dimension quantitative structure-activity relationship(3D-QSAR) studies demonstrated that introduction of bulkier substituents on the N-terminus would increase the activity. Analog Ⅱ12(IC:0.08μM) exhibited similar inhibitory activity to the lead B1, but its synthetic route was simpler than B1. Therefore, Ⅱ12 could be used as a new lead compound for the discovery eco-friendly IGRs.

关键词： Insect neuropeptide Allatostatins Juvenile hormone IGRs 3D-QSAR

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

数据采集与处理 2021年第3期36卷 489-497页

作者：李欣璐吉根林赵斌南京师范大学计算机与电子信息学院/人工智能学院南京210023

视频异常事件检测与定位旨在检测视频中发生的异常事件,并锁定其在视频中发生的位置。但是视频场景复杂多样,并且异常发生的位置随机多变,导致发生的异常事件难以被精准定位。本文提出了一种基于卷积自编码器分块学习的视频异常事件检... 详细信息

视频异常事件检测与定位旨在检测视频中发生的异常事件,并锁定其在视频中发生的位置。但是视频场景复杂多样,并且异常发生的位置随机多变,导致发生的异常事件难以被精准定位。本文提出了一种基于卷积自编码器分块学习的视频异常事件检测与定位方法,首先将视频帧进行均匀划分,提取视频帧中每一块的光流和方向梯度直方图(Histogram of oriented gradient,HOG)特征,然后为视频中的不同图块分别设计卷积自编码器以学习正常运动模式特征,最后在异常事件检测过程中利用卷积自编码器的重构误差大小进行异常判断。该方法可以有效地针对视频不同区域进行特征学习,提升了异常事件定位的准确度。所提方法在UCSD Ped1、UCSD Ped2、CUHK Avenue三个公开数据集上进行实验,结果表明该方法能够准确定位异常事件,并且帧级别AUC(Area under the curve)平均提升了5.61%。

关键词：视频异常事件检测异常事件定位分块学习卷积自编码器深度学习

Synthesis and Aphicidal Activity of Insect Kinin Analogs

在线全文

学校读者我要写书评

暂无评论

Synthesis and Aphicidal Activity of Insect Kinin Analogs

第十届全国化学生物学学术会议

作者： xinlu li Zhe Zhang Meizi Wang Mengting Chen Yimeng Zhang Dunlun Song Xinling Yang Laboratory of Pesticide Molecule Design & Discovery Department of Applied ChemistryCollege of ScienceChina Agricultural University Department of Applied Chemistry College of Plant ProtectionShenyang Agricultural University Department of Entomology College of Plant ProtectionChina Agricultural University

Insect kinins, a class of small biologically active peptides commonly found in arthropods and other invertebrates, play a role in the regulation of many physiological processes such as the release of digestive enzymes or muscle contraction, and ultimately results in death. Thus, insect kinins are regarded as new potential leads for pest control. In our previous research, an insect kinin analog Ⅳ-3[1] was discovered with 10 times aphicidal activity higher than pymetrozine. With the aim to discover new analogs with higher activity, Ⅳ-3 was chosen as a lead compound and modified by aromatic amino acid side chain and non-aromatic group substitutions at Phe site. This site is located in the corner of Ⅵ type β-turn and represents the active conformation[2] of insect kinins. We found 22 analogs had activity against the soybean aphid, especially, Ⅰ-A-8, Ⅰ-A-11, Ⅰ-B-3 and Ⅰ-B-4 showed slightly higher activity than the lead compound Ⅳ-3. The activity of the analogs suggested that aromatic groups at Phe may be not vital to activity. Primary SAR indicated that the activity is probably related to the chain length at the Phe residue, the group flexibility, the hydrophility and steric hindrance effect.

关键词： Insect kinin analogs Pentapeptide Structure Optimization Synthesis Aphicidal Activity Structure-activity Relationship

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

氢氧化镁改性活性炭对Cu(Ⅱ)的吸附

精细化工 2020年第1期37卷 130-134,146页

作者：李鑫璐赵建海王康李文朴天津城建大学环境与市政工程学院天津300384

以氢氧化镁和活性炭为原料,在30℃条件下采用反应结晶技术制备了氢氧化镁改性活性炭材料(Mg-GAC),通过SEM、XRD对改性前后活性炭进行了表征,考察了温度、时间和pH对复合材料吸附废水中Cu(Ⅱ)的影响。结果表明,GAC经改性后,比表面积增至7... 详细信息

以氢氧化镁和活性炭为原料,在30℃条件下采用反应结晶技术制备了氢氧化镁改性活性炭材料(Mg-GAC),通过SEM、XRD对改性前后活性炭进行了表征,考察了温度、时间和pH对复合材料吸附废水中Cu(Ⅱ)的影响。结果表明,GAC经改性后,比表面积增至738.01 m^2/g。在Mg-GAC投加量为0.3 g、Cu(Ⅱ)质量浓度为0.04g/L、温度为25℃、pH为7的条件下反应2h,其吸附量达到11.66mg/g。Cu(Ⅱ)的吸附过程符合Langmuir等温模型,为单层吸附。

关键词：改性活性炭氢氧化镁 Cu(Ⅱ) 吸附水处理技术与环境保护

在线全文

学校读者我要写书评

暂无评论

监控视频中异常事件检测技术研究进展

南京航空航天大学学报 2020年第5期52卷 685-694页

作者：吉根林许振李欣璐赵斌南京师范大学计算机科学与技术学院南京210046

异常事件检测技术是当前智能监控技术研究领域关注的一个热点,作为计算机视觉的重要研究内容,其主要目标是利用计算机自动检测出可被视为异常的事件。传统方法存在低层视频特征描述能力弱,异常检测方法计算代价大,对复杂场景建模时鲁棒... 详细信息

异常事件检测技术是当前智能监控技术研究领域关注的一个热点,作为计算机视觉的重要研究内容,其主要目标是利用计算机自动检测出可被视为异常的事件。传统方法存在低层视频特征描述能力弱,异常检测方法计算代价大,对复杂场景建模时鲁棒性差等方面的限制。本文结合国内外的研究现状和目前的主流方法,介绍了监控视频中异常事件检测涉及的基本技术,分析了各类监控视频特征提取方法、特征学习模型和异常检测方法的优缺点,整理归纳了可用于监控视频中异常事件检测的常用实验数据集,最后讨论了监控视频中异常事件检测技术的难点、挑战及未来发展趋势。

关键词：异常事件检测监控视频分析行为识别计算机视觉机器学习