检索结果-南通市图书馆

Science China Chemistry 2022年第10期65卷 1945-1952页

作者： Kun Yao Zheng Liu Hang Li Dan Xu Wen-Hua Zheng yi-wu quan yi-Xiang Cheng Jiangsu Key Laboratory of Advanced Organic Materials School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Key Laboratory of High Performance Polymer Material and Technology of Ministry of Education Department of Polymer Science and EngineeringSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

We report the rational design of a dual stimulus-activated quaternary chiral emission nematic liquid crystals(Q-N*-LCs)containing light-driven chiral dopant R-S-R-1,a static chiral dopant S-2 and an achiral Nile Red(NR)in a nematic liquid crystal(SLC1717).The dopant R-S-R-1 acts as a dynamic chiral donor and an energy donor,and the achiral NR serves as a circularly polarized luminescence(CPL)emitter and energy acceptor.Interestingly,this kind of Q-N*-LCs appears reversal CPL emission direction(L-CPL)using 365 nm UV light irradiation compared with the initial state(R-CPL).Most importantly,the“On-Off”CPL switch behavior of Q-N*-LCs can be repeatedly driven by revoking or rearranging the applied direct current(DC)electric field.An OR chiral information logic gate demonstrates that this dual driven Q-N*-LCs can be potentially used for chiral information storage and coding.

关键词： chiral supramolecular liquid crystals circularly polarized luminescence light and electricity dual stimuli-activated Förster resonance energy transfer

在线全文

学校读者我要写书评

暂无评论

基于深度学习的小目标检测基准研究进展

电子学报 2024年第3期52卷 1016-1040页

作者：童康吴一全南京航空航天大学电子信息工程学院江苏南京211106

小目标检测是计算机视觉中极具挑战性的任务.它被广泛应用于遥感、交通、国防军事和日常生活等领域.相比其他视觉任务,小目标检测的研究进展相对缓慢.制约因素除了学习小目标特征的内在困难,还有小目标检测基准,即小目标检测数据集的稀... 详细信息

小目标检测是计算机视觉中极具挑战性的任务.它被广泛应用于遥感、交通、国防军事和日常生活等领域.相比其他视觉任务,小目标检测的研究进展相对缓慢.制约因素除了学习小目标特征的内在困难,还有小目标检测基准,即小目标检测数据集的稀缺以及建立小目标检测评估指标的挑战.为了更深入地理解小目标检测,本文首次对基于深度学习的小目标检测基准进行了全新彻底的调查.系统介绍了现存的35个小目标数据集,并从相对尺度和绝对尺度(目标边界框的宽度或高度、目标边界框宽高的乘积、目标边界框面积的平方根)对小目标的定义进行全面总结.重点从基于交并比及其变体、基于平均精度及其变体以及其他评估指标这3方面详细探讨了小目标检测评估指标.此外,从锚框机制、尺度感知与融合、上下文信息、超分辨率技术以及其他改进思路这5个角度对代表性小目标检测算法进行了全面阐述.与此同时,在6个数据集上对典型评估指标(评估指标+目标定义、评估指标+单目标类别)下的代表性小目标检测算法进行性能的深入分析与比较,并从小目标检测新基准、小目标定义的统一、小目标检测新框架、多模态小目标检测算法、旋转小目标检测以及高精度且实时的小目标检测这6个方面指出未来可能的发展趋势.希望该综述可以启发相关研究人员,进一步促进小目标检测的发展.

关键词：小目标检测深度学习小目标评估指标小目标数据集小目标定义小目标检测基准

Sequential enantioselective Ugi-4CR/post-Ugi transformation strategy:a precise construction of structurally diverse azaspiro polycyclic scaffolds

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 576-586页

作者： Xiao-Bao wu Jun-Xiu Shi yi-Ming Ou Hua-Jie Jiang yi-Jun Fang Qi-Ming Wang quan Gao Jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and ApplicationAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefei230036China

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic scaffolds.Structurally diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results(up to 99:1 e.r.,>95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(Ⅲ) complexes.

关键词： asymmetric catalysis post-Ugi transformation anionic stereogenic-at-cobalt(Ⅲ)complex azaspiro polycyclic scaffold one-pot synthesis

Gene therapy for monogenic disorders: challenges, strategies, and perspectives

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2024年第2期51卷 133-143页

作者： yi Zhang Zhi-ying wu Department of Medical Genetics and Center for Rare Diseases Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang 310009China Department of Neurology Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang 310009China Key Laboratory of Medical Neurobiology of Zhejiang Province HangzhouZhejiang 310009China

Monogenic disorders refer to a group of human diseases caused by mutations in single genes. While disease-modifying therapies have offered some relief from symptoms and delayed progression for some monogenic diseases, most of these diseases still lack effective treatments. In recent decades, gene therapy has emerged as a promising therapeutic strategy for genetic disorders. Researchers have developed various gene manipulation tools and gene delivery systems to treat monogenic diseases. Despite this progress, concerns about inefficient delivery, persistent expression, immunogenicity, toxicity, capacity limitation, genomic integration, and limited tissue specificity still need to be addressed. This review gives an overview of commonly used gene therapy and delivery tools, along with the challenges they face and potential strategies to counter them.

关键词： Gene therapy Monogenic diseases Geneediting Genedelivery Challenges

Mitochondria-targeted nanoparticles overcome chemoresistance via downregulating BACH1/CD47 axis in ovarian carcinoma

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

Chinese Chemical Letters 2024年第5期35卷 344-350页

作者： Ke Gong Jinghan Liao Jiangtao Lin quan Wang Zhihua wu Liting Wang Jiali Zhang yi Dong Yourong Duan Jianhua Chen State Key Laboratory of Systems Medicine for Cancer Shanghai Cancer InstituteRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200032China Department of Ultrasound Xinhua HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200092China Department of Oncology Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 200080China

The platinum-based chemotherapy is a routine strategy for the treatment of ovarian cancer,while it is prone to chemoresistance in clinical,which hinders the treatment.Therefore,it is urgently needed to elucidate the underlying mechanism of drug resistance and form the appropriate strategy.The sequencing results showed that cisplatin(DDP)resistant ovarian cancer overexpressed BTB and CNC homology 1(BACH1),and up-regulated the“don’t eat me”signal CD47.We identified that hemin,a BACH1 inhibitor,could effectively down-regulate BACH1 and simultaneously inhibit CD47.Moreover,hemin has a synergistic effect with DDP.We designed a pH-responsive nanoparticle(H/D@FA-CaP-NPs)in which folic acid(FA)ensured targeting of ovarian cancer cells,while hemin inhibited BACH1 as well as down-regulated CD47,achieving the promotion of apoptosis of tumor cells and inducing phagocytosis of tumors by macrophages.Moreover,hemin has a synergistic effect with DDP to promote apoptosis of tumor cells.Structurally,hemin and DDP was encapsulated within hydrophobic 1,2-distearoyl-sn-glycero-3-phosphoethanolamine(DSPE)to form a tight core,and hydrophilic polyethylene glycol 2000(PEG2000)and calcium phosphate(CaP)formed the outside shell,and FA was modified on the surface of nanoparticles.In terms of function,(a)FA enhanced the active targeting of nanoparticles to tumors;(b)NPs targeted mitochondria to induce reactive oxygen species(ROS)production;(c)hemin encapsulated in nanoparticles could specifically target BACH1,thereby down regulating CD47;(d)hemin had a synergistic effect with DDP,thus augmenting the chemotherapy.Altogether,mitochondria-targeted nanoparticles H/D@FA-CaP-NPs promoted tumor apoptosis and mobilized phagocytosis to treat tumor,providing a novel scheme for clinical treatment of cisplatin-resistant ovarian carcinoma.

关键词： Cisplatin-resistant Hemin BACH1 CD47 Phagocytosis ROS Synergistic effect

Some Convergence Properties for Weighted Sums of Martingale Difference Random Vectors

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第4期40卷 1127-1142页

作者： yi wu Xue Jun WANG School of Big Data and Artificial Intelligence Chizhou UniversityChizhou 247000P.R.China School of Big Data and Statistics Anhui UniversityHefei 230601P.R.China

Let{X_(ni),F_(ni);1≤i≤n,n≥1}be an array of R^(d)martingale difference random vectors and{A_(ni),1≤i≤n,n≥1}be an array of m×d matrices of real numbers.In this paper,the Marcinkiewicz-Zygmund type weak law of large numbers for maximal weighted sums of martingale difference random vectors is obtained with not necessarily finite p-th(1

关键词： Martingale difference random vectors weighted sums Marcinkiewicz–Zygmund type weak law of large numbers complete convergence strong law of large numbers multivariate simple linear regression model

Effect of FeSi additive in dual-chamber sample cup on thermal analysis characteristic values and vermiculating rate of compacted graphite iron

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第1期21卷 91-100页

作者： De-quan Shi Ze-yu Liu Gui-li Gao yi-cheng Feng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China School of Materials Science and Chemical Engineering Harbin University of Science&TechnologyHarbin 150040China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China

Thermal analysis plays a key role in the online inspection of molten iron quality.Different solidification process of molten iron can be reflected by thermal analysis curves,and silicon is one of important elements affecting the solidification of molten iron.In this study,FeSi75 was added in one chamber of the dual-chamber sample cup,and the influences of FeSi75 additive on the characteristic values of thermal analysis curves and vermiculating rate were investigated.The results show that with the increase of FeSi75,the start temperature of austenite formation TALfirstly decreases and then increases,but the start temperature of eutectic growth TSEF,the lowest eutectic temperature TEU,temperature at maximum eutectic reaction rate TEM,and highest eutectic temperature TERkeep always an increase.The temperature at final solidification point TEShas little change.The FeSi75 additive has different influences on the vermiculating rate of molten iron with different vermiculation,and the vermiculating rate increases for lower vermiculation molten iron while decreases for higher one.According to the thermal analysis curves obtained by a dual-chamber sample cup with 0.30wt.%FeSi75 additive in one chamber,the vermiculating rate of molten iron can be evaluated by comparing the characteristic values of these curves.The time differenceΔtERcorresponding to the highest eutectic temperature TERhas a closer relationship with the vermiculating rate,and a parabolic regression curve between the time differenceΔtERand vermiculating rateηhas been obtained within the range of 65%to 95%,which is suitable for the qualified melt.

关键词： FeSi75 additive characteristic value vermiculating rate thermal analysis compacted graphite iron

Winter extreme precipitation over the Tibetan Plateau influenced by Arctic sea ice on interdecadal timescale

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第1期15卷 42-51页

作者： Qing-quan LI Miao BI Song YANG Qing-Yuan wu yi-Hui DING Xin-Yong SHEN Xiao-Ting SUN Meng-Chu ZHAO China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China CMA Key Open Laboratory of Transforming Climate Resources to Economy Chongqing Institute of Meteorological SciencesChongqing 401147China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Zhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China

The Tibetan Plateau(TP)and the Arctic are the most sensitive regions to global climate change.However,the interdecadal varibility of winter extreme precipitation over the TP and its linkage with Arctic sea ice are still unclear.In this study,the characteristics and mechisnems of the TP extreme precipitation(TPEP)influenced by Arctic sea ice on interdecadal timescale are studied based on the daily precipitation,monthly sea ice concentration and ERA5 reanalysis data from 1980 to 2018.We found that the dominant mode of the TPEP in winter mostly exhibits a uniform spatial variation on the interdecadal timescale,with an opposite weak variation in the southeastern TP,and the Arctic sea ice concentration(SIC)before 2002 are larger than that after 2003.The interdecadal variation of TPEP is affected by two teleconnection wave trains regulated by the Barents and Kara Sea ice.In the light ice years,a remarkable positive geopotential height(HGT)anomaly appears over the Barents-Kara Sea and a remarkable negative HGT anomaly is located over the Lake Baikal.Two wave trains originating over the Barents-Kara Sea can be observed.The southern branch forms a wave train through the North Atlantic along the subtropical westerly jet stream,showing a‘+-+-+'pattern of HGT anomalies from Arctic to the TP.Negative HGT anomaly controls the western TP,which creates dynamic and water vapor conditions for the TPEP.The northern branch forms a wave train through the Lake Baikal and the southeast of the TP,showing a‘+-+'HGT anomaly distribution.Positive HGT anomaly controls the southeastern TP,which is not conducive to precipitation in the region.When the SIC in the Barents-Kara Sea increases,the situation is opposite.The above analysis also reveals the reason for the difference in the east-west distribution of the TPEP.

关键词： Arctic sea ice Tibetan Plateau Winter extreme precipitation Rossby wave activity Interdecadal variation

Two-dimensional semiconductor heterostructures for photocatalytic CO2 conversion

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

Science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang wu Mingyu wu Yongfu Sun yi Xie Hefei National Research Center for Physical Sciences at Microscale University of Science and Technology of China

The CO2reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon cycle. Owing to the intriguing features of the two-dimensional（2D） heterostructures, it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO2reactivity. From this perspective, we surveyed the fundamental insights of 2D semiconductor heterostructures, involving the fabrication strategies and classification of the 2D semiconductor heterostructure. Also, we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO2photocatalytic influenced factors, including the solar energy utilization, photogenerated carriers separation, and redox reaction kinetics. Afterwards, we showed the significant advantages of 2D heterostructures in elevating CO2photoreduction performance, focusing on activity, selectivity and photostability. By analyzing the limitations and developments, we ended by putting forward insights into the further researches about the CO2photocatalysts and reactor design, even industrial applications.

关键词： CO2 conversion photocatalysis two-dimensional semiconductor heterostructures

A proton birdcage coil integrated with interchangeable single loops for multi-nuclear MRI/MRS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第2期25卷 168-180页

作者： yi ZHANG Zhiyan quan Feiyang LOU Yujiao FANG Garth J.THOMPSON Gao CHEN Xiaotong ZHANG Department of Neurosurgery the Second Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou310009China Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases Hangzhou310009China MOE Frontier Science Center for Brain Science and Brain-machine Integration Zhejiang UniversityHangzhou310058China Interdisciplinary Institute of Neuroscience and Technology College of Biomedical Engineering&Instrument ScienceZhejiang UniversityHangzhou310027China School of Medicine Zhejiang UniversityHangzhou310020China iHuman Institute School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China College of Electrical Engineering Zhejiang UniversityHangzhou310027China

Energy metabolism is fundamental for life.It encompasses the utilization of carbohydrates,lipids,and proteins for internal processes,while aberrant energy metabolism is implicated in many diseases.In the present study,using three-dimensional(3D)printing from polycarbonate via fused deposition modeling,we propose a multi-nuclear radiofrequency(RF)coil design with integrated 1H birdcage and interchangeable X-nuclei(^(2)H,^(13)C,^(23)Na,and^(31)P)single-loop coils for magnetic resonance imaging(MRI)/magnetic resonance spectroscopy(MRS).The single-loop coil for each nucleus attaches to an arc bracket that slides unrestrictedly along the birdcage coil inner surface,enabling convenient switching among various nuclei and animal handling.Compared to a commercial 1H birdcage coil,the proposed 1H birdcage coil exhibited superior signal-excitation homogeneity and imaging signal-to-noise ratio(SNR).For X-nuclei study,prominent peaks in spectroscopy for phantom solutions showed excellent SNR,and the static and dynamic peaks of in vivo spectroscopy validated the efficacy of the coil design in structural imaging and energy metabolism detection simultaneously.

关键词： Energy metabolism Magnetic resonance imaging(MRI) Magnetic resonance spectroscopy(MRS) Multi-nuclear Radiofrequency coil Three-dimensional(3D)printing