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Characterization of DNA Intercalator Bound to Calf Thymus DNA:Ionic Strength and pH Value Effects

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Chemical Research in Chinese Universities 2009年第4期25卷 492-496页

作者： yuan chun-li ZHANG Zhi-chao SONG Ting WU Gui-ye Department of Gynecology and Obstetrics First Hospital of Jilin University Changchun 130021 P. R. China State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116012 P. R. China

By means of circular dichroism（CD） spectrum coupled with UV-Vis and fluorescence spectra,the binding model of DNA intercalator A1{4-（2-diethylamino-ethylamino）-8-oxo-8H-acenaphtho[1,2-b]pyrrole-9-carbonitrile} to calf thymus（CT） DNA was investigated,depending on the values of R（R is defined as the ratio of the concentration of A1 to CT DNA base pairs） and different outer *** A1 were intercalated into the CT DNA base pairs in different orientations in the intercalation pocket at a lower R value（R≤0.20）,while A1 molecules aggregated on the surface of the helix of the CT DNA as the R value *** influence of NaCl on the binding was smaller because the electrostatic interaction only provided approximately 16% of the overall free energy of *** protonated diethylamine substitution would influence the binding geometry greatly at a low pH value via forming hydrogen bonds with the exposed C=O group on DNA surface.

关键词： DNA intercalator 4-(2-Diethylamino-ethylamino)-8-oxo-8H-acenaphtho[1,2-b]pyrrole-9-carbonitrile Ionic strength

Production and constraints for a massive dark photon at electron-positron colliders

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Chinese Physics C 2020年第2期44卷 62-71页

作者： Jun Jiang chun-yuan li Shi-yuan li Shankar Dayal Pathak Zong-Guo Si Xing-Hua Yang School of Physics Shandong UniversityJinanShandong 250100China Department of Physics Lovely Professional UniversityPhagwaraPunjab144411India

Dark sector may couple to the Standard Model via one or more mediator *** discuss two types of mediators:the dark photon A’ and the dark scalar mediator Φ .The total cross-sections and various differential distributions of the processes e+e-→qqA’ and e+e→qqφ（q=u,d,c,s and b quarks） are *** focus on the study of the invisible due to the cleaner background at future e+*** is found that the kinematic distributions of the two-jet system could be used to identify（or exclude） the dark photon and the dark scalar mediator,as well as to distinguish between *** further study the possibility of a search for dark photons at a future CEPC experiment with s1/2=91.2 GeV and 240 *** CEPC running at s1/2=91.2 GeV,it would be possible to perform a decisive measurement of the dark photon（20 GeV limits of the integrated luminosity for the significance S/B1/2=2σ,3σ and 5σ are presented.

关键词： dark photon dark scalar mediator CEPC

Intercalation,Cytotoxicity,and Molecular Modeling of Acenaphtho[1,2-b]pyrrole Chromophores as a New Family of Antitumor Agents

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Chemical Research in Chinese Universities 2008年第4期24卷 449-453页

作者： ZHANG Zhi-chao ZHANG Jing yuan chun-li WU Gui-ye QIAN Xu-hong State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116012 P. R. China School of Environmental and Biological Science and Technology Dalian University of Technology Dalian 116024 P. R. China The First Clinic Hospital Jilin University Changchun 130021 P. R. China State Key Laboratory of Natural and Biomimetic Drugs Beijing 100083 P. R. China Shanghai Key Laboratory of Chemical Biology East China University of Science and Technology Shanghai 200237 P. R. China

To explore new platform for DNA intercalation and potent antitumor agent, a series of 8-oxo-8H- acenaphtho[1,2-b]pyrrole-9-carboxylic acid esters chromophores has been studied. Their intercalation geometries with DNA were rex;ealed through absorption titration, SYBR Green-DNA melt curve, circular dichroism（CD）, and docking studies. It was identified that some of the compounds could intercalate into DNA along their long axis parallel to the base-pair long axis, making right-handed B form DNA transform to A-like conformation. Their binding potency varied with the different steric hindrance. Their cytotoxicity（IC50） against MCF-7 cells was found to range between 1.3 to 40.9 umol/L by MTT assay. Interestingly, the IC50 values did not show any obvious correlation to their binding constants with DNA. The chromophore with a carboxyl group exhibited the most potency of intercalating DNA and could be the promising precursor for the future intercalator for DNA, while the bromide demonstrated the highest cytotoxic activity in this series of compounds.

关键词： Intercalation Cytotoxicity 8-Oxo-SH-acenaphtho[1,2-b]pyrrole-9-carboxylic acid esters

Preparation of Tolterodine Metabolite Loaded Biodegradable PLGA Microspheres

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Chemical Research in Chinese Universities 2010年第1期26卷 75-80页

作者： TENG Le-sheng JIANG Chao-jun liN Xiang-you DONG yuan-chen li chun-mei MENG Qing-fan li You-xin College of life Science Jilin University Changehun 130012 P. R. China

Biodegradable polymer poly（lactic-co-glycolic acid）（PLGA） was used to encapsulate the pharmacological activity metabolite of tolterodine by means of O/W emulsion solvent evaporation method via homogenization in the emulsification process. The influences of preparation parameters were investigated. The results indicate that increa- sing PLGA concentration from 15% to 40% made the encapsulation efficiency of 5-hydroxymethyl derivative of tol- terodine（5-HMT） increased from 55.39% to 76.32%, and the particle size increased from 34.33 μm to 70,78 lain. In addition, when homogenization speed increased from 850 r/min to 2300 r/min, both particle size and encapsulation efficiency of microspheres decreased. An increase in the volume of aqueous phase led to higher encapsulation efficiency and bigger particle size. Increasing temperature made encapsulation efficiency and particle size change significantly. While reaction temperature increased from 20 ℃ to 50 ℃, the encapsulation efficiency decreased from 70.44% to 24.07%, and particle size increased from 38.66 μm to 69.38 μm. High reaction temperature（over 40 ℃） may lead to porous surface of microspheres. Porous surface, encapsulation efficiency and particle size influenced on the in vitro release of 5-HMT together.

关键词： Poly(lactic-co-glycolic acid) Microsphere Tolterodine Tolterodine metabolite

Effect of Mn content on microstructure and properties of AlCrCuFeMnx high-entropy alloy

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China Foundry 2024年第2期21卷 147-158页

作者： Ning Wang Kai Ma Qiu-da li Yu-dong yuan Yan-chun Zhao li Feng School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Advanced Processing and Reuse of Nonferrous Metals Lanzhou 730050China CNNC Nuclear Power Operation and Management Co. Ltd.Haiyan 314300ZhejiangChina

AlCrCuFeMnx(x=0,0.5,1,1.5,and 2)high-entropy alloys were prepared using the vacuum arc melting *** microstructure and mechanical properties of AlCrCuFeMnxwere analyzed and tested by XRD,SEM,TEM,nanoindentation,and electronic universal *** results indicate that the AlCrCuFeMnxhigh-entropy alloy exhibits a dendritic structure,consisting of dendrites with a BCC structure,interdendrite regions with an FCC structure,and precipitates with an ordered BCC structure that form within the ***(Mn)has a strong affinity for dendritic,interdendritic,and precipitate structures,allowing it to easily enter these *** an increase in Mn content,the size of the precipitated nanoparticles in the dendritic region initially increases and then ***,the area fraction initially decreases and then ***,the alloy’s strength and wear resistance decrease,while its plasticity *** Al Cr Cu Fe Mn1.5alloy boasts excellent mechanical properties,including a hardness of 360 HV and a wear rate of 2.4×10^(-5)mm^(3)·N^(-1)·mm^(-1).It also exhibits impressive yield strength,compressive strength,and deformation rates of 960 MPa,1,700 MPa,and 27.5%,respectively.

关键词： high-entropy alloys microstructure mechanical properties wear resistance strengthening mechanisms

The origin and evolution of Earth's nitrogen

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National Science Review 2024年第6期11卷 56-75页

作者： yuan li State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of Sciences Bayerisches Geoinstitut Universit?t Bayreuth

Nitrogen is a vital element for life on Earth. Its cycling between the surface(atmosphere + crust) and the mantle has a profound influence on the atmosphere and climate. However, our understanding of the origin and evolution of Earth's nitrogen is still incomplete. This review presents an overview of the current understanding of Earth's nitrogen budget and the isotope composition of different reservoirs, laboratory constraints on deep nitrogen geochemistry, and our understanding of the origin of Earth's nitrogen and the deep nitrogen cycle through plate subduction and volcanism. The Earth may have acquired its nitrogen heterogeneously during the main accretion phase, initially from reduced, enstatite-chondrite-like impactors,and subsequently from increasingly oxidized impactors and minimal CI-chondrite-like materials. like Earth's surface, the mantle and core are also significant nitrogen reservoirs. The nitrogen abundance and isotope composition of these three reservoirs may have been fundamentally established during the main accretion phase and have been insignificantly modified afterwards by the deep nitrogen cycle, although there is a net nitrogen ingassing into Earth's mantle in modern subduction zones. However, it is estimated that the early atmosphere of Earth may have contained ～1.4 times the present-day atmospheric nitrogen(PAN),with ～0.4 PAN being sequestered into the crust via biotic nitrogen fixation. In order to gain a better understanding of the origin and evolution of Earth's nitrogen, directions for future research are suggested.

关键词： nitrogen isotopes silicate Earth atmosphere magma ocean

Single-pilot operations in commercial flight:Effects on neural activity and visual behaviour under abnormalities and emergencies

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Chinese Journal of Aeronautics 2024年第8期37卷 277-292页

作者： Qinbiao li chun-Hsien CHEN Kam K.H.NG Xin yuan Cho Yin YIU Human Factors and Ergonomics Laboratory Department of Aeronautical and Aviation EngineeringThe Hong Kong Polytechnic UniversityHong Kong Special Administrative Region 100872China School of Mechanical&Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

With cutting-edge technologies and considering airline human-resource-saving,a single pilot in commercial jets could be technically *** changes in captains’natural behaviours are initially required to comprehend the specific safe human performance envelope for safeguarding single-pilot flight,particularly in high-risk *** paper investigates how captains’performance transforms for fixing emergencies when operating from Dual-Pilot Operations(DPO)to Single-Pilot Operations(SPO)through a physiological-based *** pilots flew an emergency-included flight with/without first officers’*** neural activities and scanning behaviours were recorded using a 32-channel Electroencephalogram(EEG)and glasses-based eye tracker,with the observation and post-experiment questionnaires to evaluate the flight operations and pilots’*** alone,there was a significantly increased cortical activity in h and b waves over the frontal,parietal,and temporal lobes during the more complicated emergencies,and pilots focused less on the primary flight display while spending significantly more time scanning the other *** physiological fluctuating patterns associated with risky operations in SPO were highlighted by cross-correlating multimodal *** experimental-based noteworthy insights may wish to inform commercial SPO measures to lessen the persistent physiological fluctuation,assisting airlines in creating SPO-oriented intelligent flight systems to give captains adequate support for assuring safer air transportation.

关键词： Aviation engineering Single pilot operations Behaviour changes Eye tracker Electroencephalogram

Robustness of the octupole collectivity in 144Ba within the cranking covariant density functional theory in 3D lattice

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Nuclear Science and Techniques 2024年第8期35卷 124-131页

作者： Ze‑Kai li yuan‑yuan Wang Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China Hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000China

The octupole deformation and collectivity in octupole double-magic nucleus 144Ba are investigated using the Cranking covariant density functional theory in a three-dimensional lattice *** reduced B(E3)transition probability is implemented for the first time in semiclassical approximation based on the microscopically calculated electric octupole *** available data,including the I-ωrelation and electric transitional probabilities B(E2)and B(E3)are well ***,it is shown that the ground state of 144Ba exhibits axial octupole and quadrupole deformations that persist up to high spins(I≈24h).

关键词： Octupole collectivity Cranking covariant density functional theory Rotational spectrum Electric transitional probabilities

Pseudomonotonicity of Nonlinear Transformations on Euclidean Jordan Algebras

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 192-204页

作者： yuan-Min li School of Mathematics and Statistics Xidian UniversityXi’an710071China

In this paper, we have introduced the concepts of pseudomonotonicity properties for nonlinear transformations defined on Euclidean Jordan algebras. The implications between this property and other P-properties have been studied. More importantly, we have solved the solvability problem of the nonlinear pseudomonotone complementarity problems over symmetric cones.

关键词： Euclidean Jordan algebra nonlinear transformation complementarity problem pseudomonotone