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Controlled Self-assembly of Thermo-responsive Amphiphilic H-shaped Polymer for Adjustable Drug Release

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Chinese Journal of Polymer Science 2018年第3期36卷 406-416页

作者： Yang Bai Fang-Yuan Xie Wei Tian College of Chemistry and Chemical Engineering Shaanxi University of Science and TechnologyXi'an 710021China Ministry of Education Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Macromolecular Science and Technology School of ScienceNorthwestern Polytechnical UniversityXi’an 710072China Department of Pharmacy Eastern Hepatobiliary Surgery HospitalThe Second Military Medical UniversityShanghai 200438 China

Despite the fact that some progress has been made in the self-assembly of H-shaped polymers, the corresponding self-assemblies that respond to external stimulus and are further utilized to adjust the release of drugs are still deficient. The stimuli-responsive segments with amphiphilic H-shaped structure are generally expected to enhance the controllability of self-assembly process. The synthesis and self-assembly behavior of thermo-responsive amphiphilic H-shaped polymers with poly（ethylene glycol）（PEG）, polytetrahydrofuran （PTHF） and poly（N-isopropyl acrylamide）（PNIPAM） as building blocks are reported in this paper. The inner architecture structure and size of complex micelles formed by H-shaped self-assemblies were effectively adjusted when the solution temperature was increased above the lower critical solution temperature of PNIPAM segments. Furthermore, it was found that the architecture of self-assemblies underwent a transition from the complex micelles based on primary micelles with hybrid PEG/PNIPAM shells to large complex micelles based on primary micelles with hybrid PTHF/PNIPAM cores and PEG shells during the thermal-induced self-assembly process. The adjustable release rate ofdoxorubicin （DOX） from the DOX-loaded complex micelles and basic cell experiments further proved the feasibility of these self-assemblies as the thermal-responsive drug delivery system.

关键词： H-shaped polymer Thermo-responsive polymer Amphiphilic polymer Self-assembly Drug release

On the classification of mixed floating pollutants on the Yellow Sea of China by using a quad-polarized SAR image

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Frontiers of Earth Science 2018年第2期12卷 373-380页

作者： Xiaochen WANG Yun SHAO Wei Tian Kun LI Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences University of California Los Angeles CA 90095 USA

This study explored different methodologiesusing a C-band RADARSAT-2 quad-polarized SyntheticAperture Radar （SAR） image located over China＇s YellowSea to investigate polarization decomposition parametersfor identifying mixed floating pollutants from a complexocean background. It was found that solitary polarizationdecomposition did not meet the demand for detecting andclassifying multiple floating pollutants, even after applyinga polarized SAR image. Furthermore, considering thatYamaguchi decomposition is sensitive to vegetation andthe algal variety Enteromorpha prolifera, while H/A/alphadecomposition is sensitive to oil spills, a combination ofparameters which was deduced from these two decom-positions was proposed for marine environmental mon-itoring of mixed floating sea surface pollutants. Acombination of volume scattering, surface scattering, andscattering entropy was the best indicator for classifyingmixed floating pollutants from a complex ocean back-ground. The Kappa coefficients for Enteromorpha pro-lifera and oil spills were 0.7514 and 0.8470, respectively,evidence that the composite polarized parameters based onquad-polarized SAR imagery proposed in this research isan effective monitoring method for complex marinepollution.

关键词： RADARSAT-2 polarization decomposition mixed floating pollutants classification

Curcumin Prevents Induced Drug Resistance:A Novel Function?

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Chinese Journal of Cancer Research 2011年第3期23卷 218-223页

作者： Dong Xu Wei Tian Hong Shen Department of Surgical Oncology Hangzhou 310009China Department of Medical Oncology Second Affiliated HospitalZhejiang University College of MedicineHangzhou 310009China

Objective：We supposed that it will be a promising strategy to ＂prevent＂ multidrug resistance （MDR） instead of ＂reversing＂ it.This study was designed to investigate the potency of curcumin to prevent the acquired drug resistance induced by adriamycin （ADM） in native K562 cells.Methods：K562 cells were pretreated with curcumin or 0.5% DMSO for 24 h and then were co-incubated with ADM.P-glycoprotein （P-gp） and mdr1 mRNA levels were analyzed separately by flow cytometry and quantitative real-time RT-PCR.The intracellular Rh-123 accumulation was also detected by flow cytometer.Finally,we performed a MTT assay to determine the ADM-induced cytotoxicity with or without pretreatment of curcumin.Results：P-gp and mdr1 mRNA expressions were elevated in the ADM alone group.While in the curcumin pretreated groups,the induced P-gp and mdr1 mRNA levels gradually decreased with increasing curcumin concentrations,and the Rh-123 accumulation level was almost recovered close to the control group＇s.Finally,the MTT colorimetric assay verified the enhanced effect of curcumin on ADM-induced cytotoxicity.Conclusion：Our present study suggested that curcumin exhibits the novel ability to prevent the up-regulation of P-gp and its mRNA induced by ADM.The prevention capacity is also functionally associated with the elevated intracellular drug accumulation and parallel enhanced ADM cytotoxicity.We revealed a novel function of curcumin as a potential drug resistance preventor.

关键词： Curcumin Drug resistance P-glycoprotein K562 cell

Spatial Expression of Assembly Geometric Errors for Multi-axis Machine Tool Based on Kinematic Jacobian-Torsor Model

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Chinese Journal of Mechanical Engineering 2023年第2期36卷 234-248页

作者： Ang tian Shun Liu Kun Chen wei Mo Sun Jin State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Digital Manufacture for Thin‑walled Structures School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Assembly geometric error as a part of the machine tool system errors has a significant influence on the machining accuracy of the multi-axis machine tool.And it cannot be eliminated due to the error propagation of components in the assembly process,which is generally non-uniformly distributed in the whole working space.A comprehensive expression model for assembly geometric error is greatly helpful for machining quality control of machine tools to meet the demand for machining accuracy in practice.However,the expression ranges based on the standard quasistatic expression model for assembly geometric errors are far less than those needed in the whole working space of the multi-axis machine tool.To address this issue,a modeling methodology based on the Jacobian-Torsor model is proposed to describe the spatially distributed geometric errors.Firstly,an improved kinematic Jacobian-Torsor model is developed to describe the relative movements such as translation and rotation motion between assembly bodies,respectively.Furthermore,based on the proposed kinematic Jacobian-Torsor model,a spatial expression of geometric errors for the multi-axis machine tool is given.And simulation and experimental verification are taken with the investigation of the spatial distribution of geometric errors on five four-axis machine tools.The results validate the effectiveness of the proposed kinematic Jacobian-Torsor model in dealing with the spatial expression of assembly geometric errors.

关键词： Geometric error Machine tool Jacobian-Torsor model Tolerance Spatial expression

Recent progress on multifunctional electromagnetic interference shielding polymer composites

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Journal of Materials Science & Technology 2023年第3期134卷 106-131页

作者： Ke tian Danrong Hu Quan wei Qiang Fu Hua Deng College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China Rehabilitation Medicine Center and Institute of Rehabilitation Medicine Key Laboratory of Rehabilitation Medicine in Sichuan ProvinceWest China HospitalSichuan UniversityChengdu 610041China

The explosive development of electronic devices and wireless communication technology gives rise to the issue of electromagnetic pollution,known as electromagnetic interference(EMI).The accumulation of undesirable electromagnetic radiation in space disturbs the normal function of unshielded electronic appliances and poses seriously threat to human health.Thus,the development of EMI shielding materials have emerged to solve the grim problem.Considering the complex application contexts,EMI shielding materials have evolved from traditional single-function to multi-functions to meet the ever-increasing application requirements in recent few years.This paper provides detailed insight into the current re-search status and future challenges in the advancement of polymer-based EMI shielding materials with various functions.First,the basic theory of EMI shielding,factors influencing results and the dominating characterization technologies for EMI shielding properties are summarized.Then,the comprehensive descriptions of the seven types of multifunctional EMI shields are provided with respect to their structures,fabrication methods and specific functions.Meanwhile,the corresponding critical scientific and technical issues are proposed.Based on our comprehensive analysis,the main challenges in the development of multifunctional EMI shielding materials are presented.This review aims to provide some guidance and inspire more efforts toward functional EMI shielding material research to satisfy the growing requirements for next-generation electronic systems.

关键词： Polymer-based composites Electromagnetic interference shielding Multiple losses Multifunctionality

Region coverage control for multiple stratospheric airships with combined self-/event-triggered mechanism

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Defence Technology（防务技术） 2023年第6期24卷 254-268页

作者： Yi-fei Zhang Ming Zhu tian Chen Ze-wei Zheng School of Aeronautic Science and Engineering Beihang UniversityBeijing100191China Institute of Unmanned System Beihang UniversityBeijing100191China School of Electronic and Information Engineering Beihang UniversityBeijing100191China School of Automation Science and Electrical Engineering Beihang UniversityBeijing100191China

The region coverage control problem of multiple stratospheric airships system is firstly addressed in this paper.Towards it,we propose a two-layer control framework with the artificial potential field(APF)-based region coverage control law and the adaptive tracking control law.The APF-based region coverage control law ensures the coverage task is achieved until every single stratospheric airship ends up performing station keeping where near the respective global minimum point,in which an innovative solution to the local minimum problem is put forward.The adaptive tracking control law is designed to realize motion control using tracking the desired velocity and angular velocity given by coverage control law,with the consideration of several practical control problems as unknown individual differences and external disturbances.To save resources,the combined self-/event-triggered mechanism designed therein significantly reduces the times of state information transmission and control law calculation.The effectiveness of the proposed control framework is verified through simulations.

关键词： Formation coverage control Combined self-/event-triggered control Improved artificial potential field

Accelerated life-time test of MEA durability under vehicle operating conditions in PEM fuel cell

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Frontiers in Energy 2017年第3期11卷 326-333页

作者： tian tian Jianjun TANG wei GUO Mu PAN State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Hubei Provincical Key Laboratory of Fuel Cell Wuhan University of Technology Wuhan 430070 China

In this paper, a novel accelerated test method was proposed to analyze the durability of MEA, considering the actual operation of the fuel cell vehicle. The proposed method includes 7 working conditions： open circuit voltage （OCV）, idling, rated output, overload, idling-rated cycle, idling-overload cycle, and OCV-idling cycle. The experimental results indicate that the proposed method can effectively destroy the MEA in a short time （165 h）. Moreover, the degradation mechanism of MEA was analyzed by measuring the polarization curve, CV, SEM and TEM. This paper may provide a new research direction for improving the durability of fuel cell.

关键词： polymer electrolyte membrane fuel cell accelerated life-time test load cycling test durability

Papular acantholytic dyskeratosis of the anogenital area with novel ATP2C1 gene mutations

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Chinese Medical Journal 2021年第12期134卷 1508-1510页

作者： Xue-Min Xiao Yi-Qun Jiang Wei Tian Cheng-Rang Li Department of Dermatology The Union HospitalFujian Medical UniversityFuzhouFujian 350001China Institute of Dermatology Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and Sexually Transmitted InfectionsChinese Academy of Medical Sciences and Peking Union Medical CollegeNanjingJiangsu 210042China

To the Editor:Focal acantholytic dyskeratosis(FAD)is used to describe a group of diseases with diverse clinical manifestations but characteristic histological structures.In 1984,the first case of“papular acantholytic dyskeratosis(PAD)of the vulvocrural area”was reported in a 23-year-old female with pathological manifestations of FAD and the researchers believed that it might be a new independent disease.[1]Recently,the relationship between PAD and Hailey-Hailey disease(HHD)as well as Darier disease(DD)is receiving increasing attention from scholars.We performed gene mutation screening in two patients with sporadic PAD and explored the nature of PAD.

关键词： diseases kerato sis

Stress corrosion behavior of 2195-T8 Al-Li alloy with an artificial pit exposed to a 30vol%HNO3 solution

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Chinese Journal of Aeronautics 2023年第2期36卷 304-315页

作者： Dejun LIU Gan tian Zhengwei YANG Guofeng JIN wei ZHANG Yin WANG Huali wei School of Missile Engineering Rocket Force University of EngineeringXi'an 710038China Xi'an Institute of Aerospace Composites Xi'an 710025China

This paper experimentally studied the stress corrosion behavior of 2195-T8 Al-Li alloys with prefabricated pits in 30vol%HNO3.The microstructure was observed and determined by the scanning electron microscopy and the transmission electron microscopy.The typical corrosion features,i.e.,regular or irregular corrosion pits and sub/intergranular corrosion,were investigated,and the role of stress were analyzed.The statistical results of the number and area of corrosion pits in various sizes were studied using an improved image processing method.Experimental results demonstrate that stress affects the intergranular corrosion or sub-intergranular corrosion of the alloy most,and promotes them to evolve into cracks under stress corrosion.Stress also plays a role in accelerating corrosion severity of certain corrosion feature.The number of corrosion pits with an area of 0–50μm~2 can be seen as an index to reflect the degree of corrosion.Besides,a corrosion phenomenon,i.e.,the pit bottom in the site with the maximum stress locally suffering from no severe corrosion,was observed and discussed.

关键词： Al-Li alloy Artificial pit Corrosion features Image processing Stress corrosion