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Surface modification of acrylate intraocular lenses with dielectric barrier discharge plasma at atmospheric pressure

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Science China Chemistry 2009年第8期52卷 1235-1243页

作者： WANG yao LIU ZhenMei xu ZhiKang yao Ke Institute of Ophthalmology and Eye Center Affiliated Second HospitalCollege of MedicineZhejiang UniversityHangzhou 310009China Key Laboratory of Macromolecular Synthesis and Functionalization of Ministry of Education Institute of Polymer ScienceZhejiang UniversityHangzhou 310027China

Surface modification with dielectric barrier discharge(DBD) plasma was carried out at atmospheric pressure(argon as the discharge gas) to improve the biocompatibility of hydrophobic acrylate intraocular lens(IOL).Changes of the plasma-treated IOL surface in chemical composition,morphology and hydrophilicity were comprehensively evaluated by X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FESEM),atomic force microscopy(AFM) and water contact angle(WCA) *** surface biocompatibility of the untreated and plasma-treated IOLs was compared with the adhesion behavior of platelets,macrophages and lens epithelial cells(LECs) in *** DBD plasma treatment,the hydrophilicity of the IOL surface was obviously *** changes in WCA with treatment extension may be attributed to both the introduction of oxygen or/and nitrogen-containing polar groups and the increase of surface roughness induced by plasma etching *** existence of low molecular weight oxidized material(LMWOM) was proved on the plasma-treated IOL which was caused by the chain scission effect of the plasma *** plasma-treated IOLs resisted the adhesion of platelets and macrophages *** LECs spreading and proliferation were postponed on the IOLs plasma-treated for more than 180 s,with a well maintained epithelial phenotype of *** IOL biocompatibility was improved after the DBD plasma *** speculate that slighter foreign-body reaction and later incidence of anterior capsule opacification(ACO) may be expected after implantation of the argon DBD plasma-treated IOL.

关键词： hydrophobic acrylate intraocular lens surface modification dielectric barrier discharge plasma at atmospheric pressure biocompatibility surface property

Full-field out-of-plane vibration displacement acquisition based on speckle-projection digital image correlation and its application in damage localization

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International Journal of Mechanical System Dynamics 2022年第4期2卷 363-373页

作者： Shancheng Cao Jinwei Yan Haibo nian Chao xu School of Astronautics Northwestern Polytechnical UniversityXi'anChina Yangtze River Delta Research Institute of Northwestern Polytechnical University TaicangJiangsuChina China Electronic Product Reliability and Environmental Testing Research Institute GuangzhouChina Guangdong Provincial Key Laboratory of Electronic Information Products Reliability Technology GuangzhouChina

Stereo-digital image correlation(Stereo-DIC)has been widely explored for modal analysis in plate-type structures due to its noncontact and full-field ***,when the traditional stereo-DIC is adopted to capture the out-of-plane displacements,several challenging issues exist such as the development of surface speckles,asynchronous camera recording,and efficiency and accuracy degradation due to high computation ***,with the captured out-of-plane displacements,effective and efficient evaluation of the high spatial resolution mode shapes and their application to damage localization are also critical *** tackle these issues,a speckle-projection DIC technique using a single high‐speed camera is proposed to obtain the out-of-plane vibration ***,an enhanced peak-picking modal analysis method is adopted to enhance the estimation accuracy and efficiency of mode *** addition,the low‐rank property of mode shapes in an intact state and the spatial sparse property of damage locations are harnessed for the detection of damage positions without requiring reference data on the healthy ***,the modal analysis and damage localization results based on the proposed speckle-projection DIC are compared with those of the traditional two-camera stereo-DIC technique to verify its feasibility and *** is found that the differences in the identified resonant frequencies between these two methods are smaller than 1%for higher ***,the proposed speckle-projection DIC has the same accuracy as the traditional two-camera stereo-DIC in terms of measurement accuracy,mode shape estimation,and damage localization.

关键词： damage localization digital image correlation low-rank property modal analysis out-of-plane displacement

Prompt optical emission from gamma-ray bursts with multiple timescale variability of central engine activities

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Research in Astronomy and Astrophysics 2014年第4期14卷 411-422页

作者： Si-yao xu Zhuo Li Department of Astronomy and Kavli Institute for Astronomy and Astrophysics Peking University Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences

Complete high-resolution light curves of GRB 080319B observed by Swift present an opportunity for detailed temporal analysis of prompt optical emission. With a two-component distribution of initial Lorentz factors, we simulate the dynamical process of shells being ejected from the central engine in the framework of the in- ternal shock model. The emitted radiations are decomposed into different frequency ranges for a temporal correlation analysis between the light curves in different energy bands. The resulting prompt optical and gamma-ray emissions show similar tempo- ral profiles, with both showing a superposition of a component with slow variability and a component with fast variability, except that the gamma-ray light curve is much more variable than its optical counterpart. The variability in the simulated light curves and the strong correlation with a time lag between the optical and gamma-ray emis- sions are in good agreement with observations of GRB 080319B. Our simulations suggest that the variations seen in the light curves stem from the temporal structure of the shells injected from the central engine of gamma-ray bursts. Future observations with high temporal resolution of prompt optical emission from GRBs, e.g., by UFFO- Pathfinder and SVOM-GWAC, will provide a useful tool for investigating the central engine activity.

关键词： gamma rays: bursts- GRB 080319B

Synthesis and Antitumor Activity of 7-Substituted Derivatives of Homocamptothecin

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Chinese Chemical Letters 2006年第6期17卷 720-722页

作者： Zhen Yuan MIAO Wan nian ZHANG Jian Zhong yao Chun Quan SHENG Yun Long SONG Hui xu Min ZHANG Jing ZHANG School of Pharmacy Second Military Medical University Shanghai 200433

Thirteen homocamptothecin derivatives were synthesized and in vitro antitumor activities were evaluated by the standard MTT method. The results showed that some of the homocamptothecin derivatives had higher antitumor... 详细信息

关键词： Antitumor activity homocamptothecin synthesis.

Polyprenylated acylphloroglucinols from the fruits of Hypericum henryi

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Science China Chemistry 2016年第9期59卷 1216-1223页

作者： Yang Liao Shu-Ya Yang Xiao-nian Li Xing-Wei Yang Gang xu State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of Botany Chinese Academy of Sciences Kunming 650201 China University of Chinese Academy of Sciences Beijing 100049 China

Hyphenrones R–X(1–7), seven new polyprenylated acylphloroglucinols derivatives, were isolated from the fruits of Hypericum henryi, together with eight know analogues. Compounds 1 and 2 were elucidated to possess complex caged skeleton, while compounds 3–6 shared a common 3,9-epoxy moiety deriving from the normal polyprenylated acylphloroglucinols with a bicyclo[3.3.1]nonane-2,4,9-trione core. The new structures were elucidated on the basis of the interpretation of nuclear magnetic resonance(NMR) data, circular dichroism(CD) comparison, and single-crystal X-ray diffraction. In the bioassay, several compounds exhibited inhibitory activities against human tumor cell lines in vitro.

关键词： polyprenylated acylphloroglucinols Hypericum henryi hyphenrones R-X antitumor

Numerical study on tensile failures of heterogeneous rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第1期12卷 50-58页

作者： Ying xu Wei yao Kaiwen Xia State Key Laboratory of Hydraulic Engineering Simulation and Safety School of Civil EngineeringTianjin UniversityTianjin300072China Department of Civil and Mineral Engineering University of TorontoOntarioM5S 1A4Canada

Many experimental results have demonstrated the apparent discrepancy of a rock material between its flexural tensile strength measured using various bending methods and its tensile strength measured using direct tension method or Brazil disc(BD)*** understand the physical mechanism for such discrepancy,numerical simulation using the realistic failure process analysis(RFPA)is carried out in this work to simulate the tensile failure of heterogeneous *** tension and semi-circular bend(SCB)tests are simulated using RFPA for rock materials with different levels of inhomogeneity,which is characterized by the homogeneity index of the Weibull distribution used in *** numerical results show that the discrepancy in the tensile strength values is caused by the inhomogeneity of the rock ***,non-local failure criterion is adopted to calculate the characteristic length of the rock materials used in the *** is shown that below a certain value of the homogeneity index,both the characteristic length and discrepancy between two types of tensile strengths of rock decrease with increase of the homogeneity index up to a critical value,at which the discrepancy disappears and the rock material is essentially homogeneous.

关键词： Tensile strength Flexural tensile strength Realistic failure process analysis(RFPA) Homogeneity index Non-local failure Characteristic length

Physics-informed Neural Network for Force-free Magnetic Field Extrapolation

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Research in Astronomy and Astrophysics 2024年第10期24卷 159-169页

作者： yao Zhang Long xu Yihua Yan State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 101408China Faculty of Information Science and Engineering Ningbo UniversityNingbo 315211China

In this paper,we propose a physics-informed neural network extrapolation method that leverages machine learning techniques to reconstruct coronal magnetic *** enhance the classical neural network structure by introducing the concept of a quasi-output layer to address the challenge of preserving physical constraints during the neural network extrapolation ***,we employ second-order optimization methods for training the neural network,which are more efficient compared to the first-order optimization methods commonly used in classical machine *** approach is evaluated on the widely recognized semi-analytical model proposed by Low and *** results demonstrate that the deep learning method achieves high accuracy in reconstructing the semianalytical model across multiple evaluation *** addition,we validate the effectiveness of our method on the observed magnetogram of active region.

关键词： Sun:magnetic fields Sun:corona magnetohydrodynamics(MHD)

The impact of high-temperature stress on rice: Challenges and solutions

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The Crop Journal 2021年第5期9卷 963-976页

作者： Yufang xu Chengcai Chu Shanguo yao State Key Laboratory of Plant Genomics Institute of Genetics and Developmental Biologythe Innovative Academy for Seed DesignChinese Academy of SciencesBeijing 100101China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100039China College of Life Science Henan Agricultural UniversityZhengzhou 450002HenanChina

Heat stress (HS) caused by rapidly warming climate has become a serious threat to global food *** (Oryza sativa L.) is a staple food crop for over half of the world’s population,and its yield and quality are often reduced by *** is an urgent need for breeding heat-tolerant rice *** plants show various morphological and physiological symptoms under *** analysis of the symptoms(phenotyping) is essential for the selection of elite germplasm and the identification of thermotolerance *** response to HS,rice plants trigger a cascade of events and activate complex transcriptional regulatory *** homeostasis under HS is especially important for rice thermotolerance,which is affected by protein quality control,effective elimination of toxic proteins,and translational *** some agronomic and genetic approaches for improving heat tolerance have been adopted in rice,the molecular mechanisms underlying rice response to HS are still elusive,and success in engineering rice thermotolerance in breeding has been *** this review,we summarize HS-caused symptoms in rice and progress in heat-stress sensing and signal cascade research,and propose approaches for improving rice thermotolerance in future.

关键词： Heat stress Rice Transcriptional regulation Protein homeostasis Thermotolerance breeding

Reactive oxygen and nitrogen species regulate porcine embryo development during pre-implantation period:A mini-review

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Animal Nutrition 2021年第3期7卷 823-828页

作者： Zhen Luo Jianbo yao Jianxiong xu School of Agriculture and Biology Shanghai Jiao Tong UniversityShanghai Key Laboratory of Veterinary BiotechnologyShanghaiChina Division of Animal and Nutritional Sciences West Virginia UniversityMorgantownWVUSA

Significant porcine embryonic loss occurs during conceptus morphological elongation and attachment from d 10 to 20 of pregnancy,which directly decreases the reproductive efficiency of sows.A successful establishment of pregnancy mainly depends on the endometrium receptivity,embryo quality,and utero-placental microenvironment,which requires complex cross-talk between the conceptus and *** understanding of the molecular mechanism regulating the uterine-conceptus communication during porcine conceptus elongation and attachment has developed in the past *** oxygen and nitrogen species,which are intracellular reactive metabolites that regulate cell fate decisions and alter their biological functions,have recently reportedly been involved in porcine conceptus elongation and *** mini-review will mainly focus on the recent researches about the role of reactive ox-ygen and nitrogen species in regulating porcine embryo development during the pre-implantation period.

关键词： Reactive oxygen and nitrogen species Pre-implantation Porcine Embryo development