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Recent advances in DNAzyme-based gene silencing

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Science China Chemistry 2017年第5期60卷 591-601页

作者： Huanhuan fan Xiaobing Zhang Yi lu Molecular Science and Biomedicine Laboratory State Key Laboratory of Chemo/Bio-Sensing and Chemometrics Collaborative Innovation Center for Chemistry and Molecular MedicineCollege of Chemistry and Chemical Engineering College of Biology Hunan University Changsha 410082 China Department of Chemistry Materials Science and Engineering University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA

DNAzymes, generated through in vitro selection processes, are single-stranded DNA catalysts that can catalyze a wide variety of reactions, such as RNA or DNA cleavage and ligation or DNA phosphorylation. Based on specific cofactor dependence and potent catalytic ability, DNAzymes have been extensively used to develop highly sensitive and specific sensing platforms for metal ions,small molecules, and biomacromolecules. However, in spite of their multiple strong enzymatic turnover properties, few reports have addressed the potential application of RNA-cleaving DNAzymes as therapeutic gene-silencing agents. The main challenges are being met with low efficiency of cellular uptake, instability and the lack of sufficient cofactors for cellular or in vivo study, which have limited the development of DNAzymes for clinical application. In recent years, substantial progress has been made to enhance the delivery efficiency and stability of DNAzymes by developing variety of methods. Smart metal oxide nanomaterials have also been used to meet the requirement of cofactors in situ. This review focuses on the gene silencing application of DNAzymes as well as their physicochemical properties. Methods of increasing the efficacy of DNAzymes in gene therapy are also discussed: delivery systems to enhance the cellular uptake, modifications to enhance the stability and smart systems to generate sufficient cofactors in situ. Finally, some future trends and perspectives in these research areas are outlined.

关键词： DNAzymes gene-silencing delivery stability cofactors

Advance of large-area achromatic flat lenses

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Light(Science & Applications) 2023年第3期12卷 318-320页

作者： Yubin fan Jin Yao Din ping Tsai Department of Electrical Engineering City University of Hong KongKowloonHong Kong 999077China Centre for Biosystems Neuroscienceand NanotechnologyCity University of Hong KongKowloonHong Kong 999077China The State Key Laboratory of Terahertz and Millimeter Waves City University of Hong KongKowloonHong Kong 999077China

A new framework of light coherence optimization is proposed to design non-ideal broadband achromatic lenses,enabling large-scale flat lenses'implementation and high *** strategy paves the way for practical planar opti... 详细信息

关键词： chromatic planar optimization

Delay-independent stabilization of nonlinear systems with multiple time-delays and its application in chaos synchronization of Rössler system

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International Journal of Intelligent Computing and Cybernetics 2016年第2期9卷 205-216页

作者： ping He Tao fan School of Automation and Electronic Information Sichuan University of Science and EngineeringSichuanChina Department of Electromechanical Engineering Faculty of Science and TechnologyUniversity of MacaoTaipaMacao

Purpose-The purpose of this paper is with delay-independent stabilization of nonlinear systems with multiple time-delays and its application in chaos synchronization of Rössler ***/methodology/approach-Based on linear matrix inequality and algebra Riccati matrix equation,the stabilization result is derived to guarantee asymptotically stable and applicated in chaos synchronization of Rössler chaotic system with multiple ***-A controller is designed and added to the nonlinear system with multiple *** stability of the nonlinear system at its zero equilibrium point is guaranteed by applying the appropriate controller signal based on linear matrix inequality and algebra Riccati matrix equation *** effective controller is also designed for the global asymptotic synchronization on the Rössler system based on the structure of delay-independent stabilization of nonlinear systems with multiple *** simulations are demonstrated to verify the effectiveness of the proposed controller ***/value-The introduced approach is interesting for delay-independent stabilization of nonlinear systems with multiple time-delays and its application in chaos synchronization of Rössler system.

关键词： Nonlinear system Chaos synchronization Delay-independent stabilization Multiple time-delay Rössler chaotic system

Local galaxies with compact cores as the possible descendants of massive compact quiescent galaxies at high redshift

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Research in Astronomy and Astrophysics 2020年第7期20卷 139-148页

作者： Ying Gao lu-lu fan Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and PhysicsInstitute of Space SciencesShandong UniversityWeihai 264209China CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

In order to test a possible evolutionary scenario of high-z compact quiescent galaxies(cQGs)that they can survive as local compact cores embedded in local massive galaxies with different morphology classes, we explore the star formation histories of local compact cores according to their spectral *** build a sample of 182 massive galaxies with compact cores(M*,core> 10^10.6 M⊙) at 0.02 ≤ z ≤ 0.06 from SDSS DR7 spectroscopic catalogue. The STARLIGHT package is used to analyze the median stacked spectra and derive the stellar ages and metallicities. Our main results show that local compact cores have the average age of about 12.1 ± 0.6 Gyr, indicating their early formation at z > 3, which is consistent with the formation redshifts of cQGs at 1 lutionary paths for high-z cQGs: most of them(> 80%)will evolve into local massive early-type galaxies according to dry minor merger, while some of them(~ 15%) will build substantial stellar/gas discs according to the late-time gas accretion and sustaining star formation, and finally grow up into spiral galaxies.

关键词： galaxies:bulges galaxies:evolution galaxies:formation galaxies:stellar content galaxies:structure

Magnetically recyclable copper modified GO/Fe_3O_4 catalyst for efficient synthesis of quinazolinones

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Chinese Chemical Letters 2016年第6期27卷 827-831页

作者： lu-lu Kong Li-Yan fan Department of Chemistry Tongji University

A series of bioactive quinazolinones were effectively synthesized by the condensation of halide benzamide with amino acid using magnetically recyclable GO/Fe3O4–CuI as catalyst. Magnetic GO/Fe3O4–CuI was prepared via a simple chemical method and characterized by FTIR, powder XRD, and *** heterogeneous copper catalyst can be easily separated from reaction mixtures by an external permanent magnet and reused without any obvious loss in activity which shows its applicability as a reusable and promising catalyst for quinazolinones synthesis.

关键词： Quinazolinones GO/Fe3O4–CuI Magnetically Recyclable Heterogeneous

Efficient Helicopter-Satellite Communication Scheme Based on Check-Hybrid LDPC Coding

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Tsinghua Science and Technology 2018年第3期23卷 323-332页

作者： ping Wang Liuguo Yin Jianhua lu Department of Electronic Engineering Tsinghua University Beijing 100084 China EDA Laboratory Research Institute of Tsinghua Universityin Shenzhen Shenzhen 518057 China. School of Information Science andTechnology Tsinghua University Beijing 100084 China EDA Laboratory Research Institute ofTsinghua University in Shenzhen Shenzhen 518057 China Department of Electronic Engineering Tsinghua University Beijing 100084 China

When implementing helicopter-satellite communications, periodical interruption of the received signal is a challenging problem because the communication antenna is intermittently blocked by the rotating blades of the helicopter. The helicopter-satellite channel model and the Forward Error Control（FEC） coding countermeasure are presented in this paper. On the basis of this model, Check-Hybrid（CH） Low-Density Parity-Check（LDPC）codes are designed to mitigate the periodical blockage over the helicopter-satellite channels. The CH-LDPC code is derived by replacing part of single parity-check code constraints in a Quasi-Cyclic LDPC（QC-LDPC） code by using more powerful linear block code constraints. In particular, a method of optimizing the CH-LDPC code ensemble by searching the best matching component code among a variety of linear block codes using extrinsic information transfer charts is proposed. Simulation results show that, the CH-LDPC coding scheme designed for the helicopter-satellite channels in this paper achieves more than 25% bandwidth efficiency improvement, compared with the FEC scheme that uses QC-LDPC codes.

关键词： helicopter-satellite communications check-hybrid Low-Density Parity-Check(LDPC) codes Extrinsic Information Transfer(EXIT) iterative decoding

Carbon-coated cubic-phase molybdenum carbide nanoparticle for enhanced photocatalytic H2-evolution performance of TiO_(2)

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Journal of Energy Chemistry 2020年第12期29卷 253-261页

作者： jinfeng Liu ping Wang jiajie fan Huogen Yu School of Materials Science and Engineering Wuhan University of Technology.122#Luoshi RoadWuhan 430070HubeiChina School of Chemistry Chermical Engineering and Life SciencesWuhan University of Technology122#Luoshi RoadWuhan 430070HubeiChina School of Materials Science and Engineering Zhengzhou University100 Science AvenueZhengzhou 450002HenanChina

Conventional hexagonal dimolybdenum carbide(Mo2 C) as a good cocatalyst has been widely applied for the enhanced photocatalytic hydrogen production of various photocatalysts. Compared with the hexagonal Mo2 C, however, the investigation about cubic molybdenum carbide(Mo C) is still very limited in photocatalytic field. In this study, carbon-coated cubic molybdenum carbide(MoC@C) nanoparticle was synthesized and used as an effective cocatalyst to improve the H2-evolution efficiency of Ti O2. The cubic MoC@C can be obtained by adjusting the mass ratio of C3 N3(NH2)3 to(NH4)6 Mo7 O(24)(2:1) and controlling the calcination temperature to 800 °C. When the above cubic MoC@C nanoparticles were evenly loaded on the Ti O2 via a sonication-assisted deposition, a homogeneous composite of TiO2/MoC@C was formed due to the strong coupling interface between TiO2 and cubic MoC nanoparticles. More importantly, the highest H2-production rate of Ti O-12/MoC@C reached 504 μmol hg^(-1)(AQE=1.43%), which was 50 times as high as that of the pure TiO2. The enhanced performance of TiO2/MoC@C can be attributed to the synergistic effect of carbon layer as an electron mediator and the cubic MoC as interfacial H2-evolution active sites. This work provides a feasible guideline to develop high-efficiency Mo-based cocatalysts for potential applications in the H2-evolution field.

关键词： TiO_(2) Cubic MoC@C Cocatalyst H_(2)production Photocatalysis

Monthly composites from Sentinel-1 and Sentinel-2 images for regional major crop mapping with Google Earth Engine

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Journal of Integrative Agriculture 2021年第7期20卷 1944-1957页

作者： luO Chong LIU Huan-jun lu Lii-ping LIU Zheng-rong KONG fan-chang ZHANG Xin-le Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102P.R.China School of Public Adminstration and Law Northeast Agricultural UniversityHarbin 150030P.R.China

Rapid and accurate access to large-scale,high-resolution crop-type distribution maps is important for agricultural management and sustainable agricultural *** to the limitations of remote sensing image quality and data processing capabilities,large-scale crop classification is still *** study aimed to map the distribution of crops in Heilongjiang Province using Google Earth Engine(GEE)and Sentinel-1 and Sentinel-2 *** obtained Sentinel-1 and Sentinel-2 images from all the covered study areas in the critical period for crop growth in 2018(May to September),combined monthly composite images of reflectance bands,vegetation indices and polarization bands as input features,and then performed crop classification using a Random Forest(RF)*** results show that the Sentinel-1 and Sentinel-2 monthly composite images combined with the RF classifier can accurately generate the crop distribution map of the study area,and the overall accuracy(OA)reached 89.75%.Through experiments,we also found that the classification performance using time-series images is significantly better than that using single-period *** with the use of traditional bands only(i.e.,the visible and near-infrared bands),the addition of shortwave infrared bands can improve the accuracy of crop classification most significantly,followed by the addition of red-edge *** common vegetation indices and Sentinel-1 data to the crop classification improved the overall classification accuracy and the OA by 0.2 and 0.6%,respectively,compared to using only the Sentinel-2 reflectance *** analysis of timeliness revealed that when the July image is available,the increase in the accuracy of crop classification is the *** the Sentinel-1 and Sentinel-2 images for May,June,and July are available,an OA greater than 80%can be *** results of this study are applicable to large-scale,high-resolution crop classification and provide key technologies f

关键词： Sentinel-1 Sentinel-2 monthly composites crop mapping Google Earth Engine

Effects of cyclodextrins on hydrolysis of malathion

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Journal of Environmental Sciences 2006年第3期18卷 572-576页

作者： ZHANG An-ping luO fan CHEN Sheng-wen LIU Wei-ping Institute of Environmental Science Zhejiang University Hangzhou 310029 China Research Center of Green Chirality College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032 China

Cyclodextrins （CDs）, with hydrophobic interior cavity and hydrophilic external surface, are capable of accelerating or inhibiting chemical degradation of organophosphorus pesticides through forming inclusion complexes between CDs and pesticides. This work evaluated the effects of CDs on hydrolysis of malathion in an attempt to assess their potential application in environmental approach. β-CD and its two derivatives, randomly methylated β-CD （RAMEB） and hydroxypropyl β-CD （HP-β-CD）, were tested. It was found that RAMEB could inhibit the hydrolysis of malathion, and this was the function of pH and temperature, the inhibitory effects increase with increasing concentration of RAMEB and elevating temperature between 15 and 35℃. On the other hand, β-CD and HP-β-CD have little or no stabilizing effects on malathion at all pH and temperature studied, except that the large concentration of β-CD and HP- β-CD can mildly reduce hydrolysis of malathion. Both 2 mol/L and 5 mol/L urea increase the inhibitory effects of RAMEB on hydrolysis of malathion at 25℃, oH 9.0.

关键词： cyclodextrin malathion hydrolysis urea