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Effect of spacer length on the liquid crystalline property of azobenzene-containing ABA-type triblock copolymers via ATRP

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Chinese Chemical Letters 2007年第9期18卷 1129-1132页

作者： xin de tang Long Cheng Gao xing He Fan Qi Feng Zhou Institute of New Materials Shandong Jiaotong UniversityJi’nan 250023China department of Polymer Science and Engineering College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The effect of flexible spacer length on the liquid crystalline property of ABA-type triblock copolymers containing azobenzene groups was investigated. For the study, the monomers, n-[4-(4-ethoxyphenylazo)phenoxy]alkyl methacrylates with varying methylene groups (n = 0, 2, 6) were used to synthesize a series of azobenzene-containing amphiphilic triblock copolymers PAnC–PEG–PAnC by atom transfer radical polymerization (ATRP). Differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and one-dimensional X-ray diffraction (1D WAXD) have shown that the glass transition temperatures of these copolymers decreased with increasing n, PA0C–PEG–PA0C has no mesophase, while both PA2C–PEG–PA2C and PA6C–PEG–PA6C have a nematic mesophase. These differences derive from the length of spacer groups between the polymer backbone and side-chain LC monomers.

关键词： Spacer group Liquid crystalline property Azobenzene Triblock copolymer Atom transfer radical polymerization (ATRP)

Synthesis and characterization of H-type amphiphilic liquid crystalline block copolymers by ATRP

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Chinese Chemical Letters 2008年第2期19卷 237-240页

作者： xin de tang Long Cheng Gao xing He Fan Qi Feng Zhou Institute of New Materials Shandong Jiaotong University Ji＇nan 250023 China department of Polymer Science and Engineering College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

H-type amphiphilic liquid crystalline block copolymers containing azobenzene were synthesized by atom transfer radical polymerization （ATRP）. Macroinitiators prepared by the esterification between poly（ethylene oxide）（PEG） and 2,2-dichloroacetyl chloride were utilized to initiate the polymerization of 6-[4-（4-ethoxyphenylazo）phenoxy]hexyl rnethacrylate （M6C）. The resulting macroinitiators and block copolymers were characterized by ^1H NMR, gel permeation chromatography （GPC）. Polarizing optical microscopy （POM） and differential scanning calorimetry （DSC） preliminarily revealed the liquid crystalline property of these block copolymers. This series of liquid crystalline block copolymers are promising in some areas, such as optical data storage, optical switch, and molecular devices.

关键词： H-type Amphiphilic Block copolymer Liquid crystalline property Atom transfer radical polymerization （ATRP）

Current status of liver transplantation for human immunodeficiency virus-infected patients in China's Mainland

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World Journal of Gastroenterology 2024年第14期30卷 1958-1962页

作者： Jian-xin tang Dong Zhao department of Liver Surgery and Organ Transplantation Center Shenzhen Third People’s HospitalThe Second Affiliated Hospital of Southern University of Science and TechnologyNational Clinical Research Center for Infectious DiseaseShenzhen 518000Guangdong ProvinceChina

According to the report from the Chinese Center for Disease Control and Prevention,the prevalence of human immunodeficiency virus(HIV)infection exceeded 1.2 million individuals by the year 2022,with an annual increase of about 80000 cases.The overall prevalence of hepatitis B surface antigen among individuals co-infected with HIV reached 13.7%,almost twice the rate of the general population in China.In addition to the well-documented susceptibility to opportunistic infections and new malignancies,HIV infected patients frequently experience liver-related organ damage,with the liver and kidneys being the most commonly affected.This often leads to the development of end-stage liver and kidney diseases.Therefore,organ transplantation has emerged as an important part of active treatment for HIV infected patients.However,the curative effect is not satisfactory.HIV infection has been considered a contraindication for organ transplantation.Until the emergence of highly active anti-retroviral therapy in 1996,the once intractable replication of retrovirus was effectively inhibited.With prolonged survival,the failure of important organs has become the main cause of death among HIV patients.Therefore,transplant centers worldwide have resu-med exploration of organ transplantation for HIV-infected individuals and reached a positive conclusion.This study provides an overview of the current landscape of HIV-positive patients receiving liver transplantation(LT)in main-land China.To date,our transplant center has conducted LT for eight end-stage liver disease patients co-infected with HIV,and all but one,who died two months postoperatively due to sepsis and progressive multi-organ failure,have survived.Comparative analysis with hepatitis B virus-infected patients during the same period revealed no statistically significant differences in acute rejection reactions,cytomegalovirus infection,bacteremia,pulmonary infections,acute kidney injury,new-onset cancers,or vascular and biliary complications.

关键词： Liver transplantation Human immunodeficiency virus Infection Hepatitis B virus End-stage liver disease China'Mainland

Microglial autophagy in neurogenesis:a new player in Alzheimer's disease

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Neural Regeneration Research 2024年第12期19卷 2573-2574页

作者： xin tang Aarti Nagayach Chenran Wang department of Cancer Biology University of Cincinnati College of MedicineCincinnatiOHUSA

While extensive studies have illuminated the impact of Alzheimer's disease(AD) on neuronal survival,there is growing evidence that abnormal postnatal neurogenesis in early AD brains contributes to disease progression.Postnatal neurogenesis serves as a mechanism to replace dead or damaged neurons.New neurons generated from neural stem cells(NSCs) in the subgranular zone(SGZ) of the dentate gyrus integrate into the existing hippocampal circuit.

关键词： Alzheimer replace integrate

Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： Yan Liu Qiu tang xin-Cheng Tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in manufacturing.For improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single Y-groove.Firstly,it summarizes the intersection forms and introduces a dual-pipe intersection model.Based on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is defined.Secondly,a novel mathematical model for plasma radius and taper compensation is established.Then,the compensation model and groove model are integrated by establishing movable frames.Thirdly,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is proposed.Through the established models and moving frames,the planned path description of cutting robot is provided in this novel scheme.The accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

Geochemical identification of a source rock affected by migrated hydrocarbons and its geological significance:Fengcheng Formation,southern Mahu Sag,Junggar Basin,NW China

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Petroleum Science 2024年第1期21卷 100-114页

作者： Wen-Long Dang Gang Gao xin-Cai You Ke-Ting Fan Jun Wu de-Wen Lei Wen-Jun He Yong tang State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum(Beijing)Beijing102249China School of GeoSciences China University of Petroleum(Beijing)Beijing102249China Exploration&development Institute Xinjiang Oil Field CompanyKaramay834000XinjiangChina

The Fengcheng Formation is a crucial source rock and the primary reservoir for oil accumulation in the Mahu Sag.Crude oils are distributed throughout the Fengcheng Formation,ranging from the edge to the interior of the sag in the southern Mahu Sag.These crude oils originate from in-situ source rocks in shallowly buried areas and the inner deep sag.During migration,the crude oil from the inner deep sag affects the source rocks close to carrier beds,leading to changes in the organic geochemical characteristics of the source rocks.These changes might alter source rock evaluations and oil-source correlation.Based on data such as total organic carbon(TOC),Rock-Eval pyrolysis of source rocks,and gas chromatography-mass spectrometry(GC-MS)of the saturated fraction,and considering the geological characteristics of the study area,we define the identification characteristics of source rock affected by migrated hydrocarbons and establish the various patterns of influence that migrated hydrocarbons have on the source rock of the Fengcheng Formation in the southern Mahu Sag.The source rocks of the Fengcheng Formation are mostly fair to good,containing mainly Type II organic matter and being thermally mature enough to generate oil.Source rocks affected by migrated hydrocarbons exhibit relatively high hydrocarbon contents(S1/TOC>110 mg HC/g TOC,Extract/TOC>30%,HC:hydrocarbon),relatively low Rock-Eval Tmax values,and relatively high tricyclic terpane contents with a descending and mountain-shaped distribution.Furthermore,biomarker composition parameters indicate a higher thermal maturity than in-situ source rocks.Through a comparison of the extract biomarker fingerprints of adjacent reservoirs and mudstones in different boreholes,three types of influence patterns of migrated hydrocarbons are identified:the edge-influence of thin sandstone-thick mudstone,the mixed-influence of sandstone-mudstone interbedded,and the full-influence of thick sandstone-thin mudstone.This finding reminds us that the influence of migrated hydrocarbons

关键词： Organic geochemistry Source rock Influence of migrated hydrocarbons Fengcheng Formation Southern Mahu Sag

Experimental study on the size effect on the equation of state of concretes under shock loading

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defence Technology（防务技术） 2024年第3期33卷 160-167页

作者： Mei Li Jian Cui Yanchao Shi Baijian tang xin Chen Key Laboratory of Coast Civil Structural Safety of the Ministry of Education Tianjin UniversityTianjin 300072China School of Civil Engineering Suzhou University of Science and Technology1701 Binhe RoadSuzhou 215011JiangsuChina School of Civil Engineering Tianjin UniversityTianjin 300072China

Adopting the classical theory of hydrocodes,the constitutive relations of concretes are separated into an equation of state(EoS)which describes the volumetric behavior of concrete material and a strength model which depicts the shear properties of concrete.The experiments on the EoS of concrete is always challenging due to the technical difficulties and equipment limitations,especially for the specimen size effect on the EoS.Although some researchers investigate the shock properties of concretes by fly-plate impact tests,the specimens used in their tests are usually in one size.In this paper,the fly-plate impact tests on concrete specimens with different sizes are performed to investigate the size effect on the shock properties of concrete materials.The mechanical background of the size effect on the shock properties are revealed,which is related to the lateral rarefaction effect and the deviatoric stress produced in the specimen.According to the tests results,the modified EoS considering the size effect on the shock properties of concrete are proposed,which the bulk modulus of concrete is unpredicted by up to 20% if size effects are not accounted for.

关键词： Concrete Equation of state Size effect Shock wave Fly-plate impact test

Fully polarized Compton scattering in plane waves and its polarization transfer

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Matter and Radiation at Extremes 2024年第3期9卷 45-56页

作者： Suo tang Yu xin Meng Wen Mamat Ali Bake Baisong Xie College of Physics and Optoelectronic Engineering Ocean University of ChinaQingdaoShandong 266100China department of Physics Hubei UniversityWuhan 430062China xinjiang Key Laboratory of Solid State Physics and devices School of Physics Science and TechnologyXinjiang UniversityUrumqi 830017China Key Laboratory of Beam Technology of the Ministry of Education and College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China

Fully polarized Compton scattering from a beam of spin-polarized electrons is investigated in plane-wave backgrounds in a broad intensity region from the perturbative to the nonperturbative regimes.In the perturbative regime,polarized linear Compton scattering is considered for investigating polarization transfer from a single laser photon to a scattered photon,and in the high-intensity region,the polarized locally monochromatic approximation and locally constant field approximation are established and are employed to study polarization transfer from an incoming electron to a scattered photon.The numerical results suggest an appreciable improvement of about 10%in the scattering probability in the intermediate-intensity region if the electron’s longitudinal spin is parallel to the laser rotation.The longitudinal spin of the incoming electron can be transferred to the scattered photon with an efficiency that increases with laser intensity and collisional energy.For collision between an optical laser with frequency1 eV and a 10 GeV electron,this polarization transfer efficiency can increase from about 20%in the perturbative regime to about 50%in the nonperturbative regime for scattered photons with relatively high energy.

关键词： polarized scattered transfer

Long-term exposure to aryl hydrocarbon receptor agonist neburon induces reproductive toxicity in male zebrafish(Danio rerio)

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Journal of Environmental Sciences 2024年第8期142卷 193-203页

作者： Fucong Zhang Chen tang Yue Zhu Qian Wang xin Huang Chunyan Yang Chengyong He Zhenghong Zuo Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems School of Life SciencesXiamen UniversityXiamen 361102China

Neburon is a phenylurea herbicide that is widely used worldwide,but its toxicity is poorly studied.In our previous study,we found that neburon has strong aryl hydrocarbon receptor(AhR)agonist activity,but whether it causes reproductive toxicity is not clear.In the present study,zebrafish were conducted as a model organism to evaluate whether environmental concentrations of neburon(0.1,1 and 10μg/L)induce reproductive disorder in males.After exposure to neburon for 150 days from embryo to adult,that the average spawning egg number in high concentration group was 106.40,which was significantly lower than 193.00in control group.This result was mainly due to the abnormal male reproductive behavior caused by abnormal transcription of genes associated with reproductive behavior in the brain,such as secretogranin-2a.The proportions of spermatozoa in the medium and high concentration groups were 82.40%and 83.84%,respectively,which were significantly lower than 89.45%in control group.This result was mainly caused by hormonal disturbances and an increased proportion of apoptotic cells.The hormonal disruption was due to the significant changes in the transcription levels of key genes in the hypothalamus-pituitary-gonadal axis following neburon treatment.Neburon treatment also significantly activated the AhR signaling pathway,causing oxidative stress damage and eventually leading to a significant increase in apoptosis in the exposed group.Together,these data filled the currently more vacant profile of neburon toxicity and might provide information to assess the ecotoxicity of neburon on male reproduction at environmentally relevant concentrations.

关键词： Zebrafish Neburon Male reproductive toxicity HPG axis AhR agonist