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Hypercrosslinking Polymers Fabricated from Divinyl Benzene via Friedel-Crafts Addition Polymerization

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Chinese Journal of Polymer Science 2022年第3期40卷 310-320,I0008页

作者： zheng-Yu duan Yan-Yan Wang Qi-Wei Pan Yun-Feng Xie Zhi-Yong Chen Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China Nutrition&Health Research Institute COFCO CorporationBeijing Key Laboratory of Nutrition&Health and Food SafetyBeijing 102209China

Microporous organic polymers with high surface area are widely used in many *** them,hypercrosslinked polymers have been extensively concerned because of their simple processes and low-cost ***,due to most state-of-the-art strategies for HCPs based on condensation reactions,the release of small molecules such as hydrochloric acid and methanol involved in such strategies brings about new hazards to ***,we propose a method of fabrication of hypercrosslinked polymers via self-addition polymerization of divinyl benzene and its crosslinking with polar aromatic *** hypercrosslinked polyDVB-based products are demonstrated by FriedelCrafts addition reaction of double bonds on DVB that can connect adjacent phenyl rings of aromatic molecules to form the crosslinked *** HCPDVB-CB obtained in 1-chlorobutane as solvent has a high micropore content and displays high surface area up to 931 m^(2)/*** this finding,DVB is used as a novel external crosslinker for knitting polar aromatic *** L-phenylalanine and bisphenol A are used as the aromatic units,the obtained HCP(Phe-DVB)and HCP(BPA-DVB)could reach surface area of 612 and 471 m^(2)/g,and have hydrogen uptake of0.62 wt%and 0.58 wt%at 77 K and 1.13 bar by comparison with HCPDVB-CB having hydrogen uptake of 0.30 wt%,respectively.

关键词： Hypercrosslinked polymers Divinyl benzene Friedel-Crafts alkylation Microporous organic polymers Gas storage

Tackling the proton limit under industrial electrochemical CO_(2)reduction by a local proton shuttle

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Carbon Energy 2024年第4期6卷 233-243页

作者： Tianye Shao Kang Yang Sheng Chen Min zheng Ying Zhang Qiang Li Jingjing duan MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringSchool of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjingChina School of Chemical Engineering and Advanced Materials The University of AdelaideAdelaideSouth AustraliaAustralia

Industrial CO_(2)electroreduction has received tremendous attentions for resolution of the current energy and environmental crisis,but its performance is greatly limited by mass transport at high current *** this work,an ion‐polymer‐modified gas‐diffusion electrode is used to tackle this proton *** is found that gas diffusion electrode‐Nafion shows an impressive performance of 75.2%Faradaic efficiency in multicarbon products at an industrial current density of 1.16 A/cm^(2).Significantly,in‐depth electrochemical characterizations combined with in situ Raman have been used to determine the full workflow of protons,and it is found that HCO_(3)^(−)acts as a proton pool near the reaction environment,and HCO_(3)^(−)and H_(3)O^(+)are local proton donors that interact with the proton shuttle−SO_(3)^(−)from *** rich proton hopping sites that decrease the activation energy,a“Grotthuss”mechanism for proton transport in the above system has been identified rather than the“Vehicle”mechanism with a higher energy ***,this work could be very useful in terms of the achievement of industrial CO_(2)reduction fundamentally and practically.

关键词： industrial CO_(2)electroreduction proton donor proton pool proton shuttle proton transport mechanism

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Science China(Life Sciences) 2024年第9期67卷 1970-1988页

作者： Jiayi Yu Changbing zheng Qiuping Guo Yulong Yin Yehui duan Fengna Li CAS Key Laboratory of Agro-ecological Processes in Subtropical Region Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic ProcessNational Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry ProductionInstitute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125China University of Chinese Academy of Sciences Beijing 100049China College of Animal Science and Technology Hunan Agricultural UniversityChangsha 410128China

We previously demonstrated that lipopolysaccharide(LPS)injection-induced immune stress could impair muscle growth in weaned piglets,but the precise mechanisms behind this remain ***,we found that chronic immune stress induced by LPS resulted in a significant reduction of 36.86%in the total muscle mass of piglets at 5 d post-treatment compared with the control *** 1 d,prior to muscle mass loss,multiple alterations were noted in response to LPS *** included a reduction in the abundance of Bacteroidetes,an increase in serum concentrations of pro-inflammatory cytokines,compromised mitochondrial morphology,and an upregulation in the expression of dynamin-related protein 1(Drp1),a critical protein involved in mitochondrial *** highlight a strong negative correlation between Bacteroidetes abundance and the levels of serum pro-inflammatory cytokines,corroborated by in vivo intervention strategies in the musculature of both pig and mouse ***,the effects of Bacteroidetes on inflammation and muscle mass loss may involve the signaling pathway of the tauro-β-muricholic acid-fibroblast growth factor ***,the induction of overexpression of inflammatory cytokines,achieved without LPS treatment through oral administration of recombinant human IL-6(rh IL-6),led to increased levels of circulating cytokines,subsequently causing a decrease in muscle ***,pre-treatment with Mdivi-1,an inhibitor of Drp-1,markedly attenuated the LPS-induced elevation in reactive oxygen species levels and rescued the associated decline in muscle ***,these data indicate that LPS-induced muscle mass loss was linked to the reduction of Bacteroidetes abundance,increased inflammation,and the disruption of mitochondrial *** insights offer promising avenues for the identification of potential therapeutic targets aimed at mitigating muscle mass loss.

关键词： Bacteroidetes inflammation mitochondrial morphology muscle mass loss piglets

Proteolytic processing of SDF-1α by matrix metalloproteinase-2 impairs CXCR4 signaling and reduces neural progenitor cell migration

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Protein & Cell 2012年第11期3卷 875-882页

作者： Hui Peng Yumei Wu Zhiyuan duan Pawel Ciborowski Jialin C.zheng Laboratory of Neuroimmunology and Regenerative Therapy University of Nebraska Medical CenterOmahaNE 68198USA Departments of Pharmacology and Experimental Neuroscience University of Nebraska Medical CenterOmahaNE 68198USA Departments of Pathology and Microbiology University of Nebraska Medical CenterOmahaNE 68198USA Institute of Genetics and Developmental Biology Chinese Academy of SciencesBeijing 100101China

Neural stem cells and neural progenitor cells(NPCs)exist throughout life and are mobilized to replace neurons,astrocytes and oligodendrocytes after ***-omal cell-derived factor 1(SDF-1,now named CXCL12)and its receptor CXCR4,an α-chemokine receptor,are critical for NPC migration into damaged areas of the *** previous studies demonstrated that immune activated and/or HIV-1-infected human monocyte-derived-macrophages(MDMs)induced a substantial increase of SDF-1 production by human ***,matrix metalloproteinase(MMP)-2,a protein up-regulated in HIV-1-infected macrophages,is able to cleave four amino acids from the N-terminus of SDF-1,resulting in a truncated SDF-1(5-67).In this study,we investigate the diverse signaling and function induced by SDF-1α and SDF-1(5-67)in human cortical ***-1(5-67)was generated by incubating human recombinant SDF-1α with MMP-2 followed by protein determination via mass spectrometry,Western blotting and ***-1α induced time-dependent phosphorylation of extracellular signal-regulated kinases(ERK)1/2,Akt-1,and diminished cyclic adenosine monophosphate(cAMP).In contrast,SDF-1(5-67)failed to induce these ***-1α activation of CXCR4 induced migration of NPCs,an effect that is dependent on ERK1/2 and Akt-1 pathways;whereas SDF-1(5-67)failed to induce NPC *** observation provides evidence that MMP-2 may affect NPC migration through post-translational processing of SDF-1α.

关键词： proteolysis chemokine neurogenesis and migration

Non-invasive in vivo Imaging Grading of Liver Fibrosis

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Journal of Clinical and Translational Hepatology 2018年第2期6卷 198-207页

作者： Hanyu Jiang Tianying zheng Ting duan Jie Chen Bin Song Department of Radiology Sichuan University West China HospitalChengduChina

Liver fibrosis(LF),a common consequence of chronic liver diseases with various etiologies,is characterized by excessive accumulation of macromolecules,including collagen,glyco-proteins and proteoglycans,in the *** can result in hepatic dysfunction,cirrhosis,portal hypertension and,in some cases,hepatocellular *** the current gold standard for diagnosing LF,liver biopsy,however,is invasive and prone to sampling errors and procedure-related ***,developing noninvasive,precise and re-producible imaging tests for diagnosing and staging LF is of great *** ultrasound(US),computed tomography(CT)and magnetic resonance(MR)imaging can depict morphological alterations of advanced LF,but have relatively limited capability characterizing early-stage *** order to optimize the diagnostic performances of noninvasive imaging techniques for LF across its entire spectrum of severity,a number of novel methods,including US elastog-raphy,CT perfusion imaging and various MR imaging–based techniques,have been established and introduced to clinical *** this review,we intended to summarize current noninvasive imaging techniques for LF,with special emphasis on the possible roles,advantages and limitations of the new emerging imaging modalities.

关键词： Liver cirrhosis Ultrasonography Computed tomography Magnetic resonance imaging

Degradation of Mg-Zn-Y-Nd alloy intestinal stent and its effect on the growth of intestinal endothelial tissue in rabbit model

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Journal of Magnesium and Alloys 2022年第8期10卷 2208-2219页

作者： Zongbin Sun Zhanhui Wang Shaokang Guan Shijie Zhu Tinghe duan Qiuxia zheng Shaopeng Liu Luoyang Central Hospital affiliated to zhengzhou University Luoyang 471000China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 45002China

Biodegradable magnesium alloys have excellent properties with respect to biodegradability, biocompatibility, and biomechanics, which may indicate a possibility of its application in intestinal stents. Investigation of Mg-Zn-Y-Nd alloy’s application in intestinal stents has been performed. This study aims to investigate the degradation behavior of Mg-Zn-Y-Nd alloy intestinal stents coated with poly(L-lactide)/paclitaxel in the intestinal environment and its biocompatibility with intestinal tissue. In this paper, Mg-Zn-Y-Nd alloy’s corrosion properties were evaluated by the immersion test in human feces, SEM and XRD, and animal tests. In vitro results showed that when the Mg-Zn-Y-Nd alloy was immersed in human feces for two weeks, its corrosion resistance could be improved by micro arc oxidation(MAO) and poly-l-lactide(PLLA) dual coating. Additionally, this result was also confirmed in vivo experiments by rabbit model. And animal tests also demonstrated that the Mg-Zn-Y-Nd alloy with MAO/PLLA/paclitaxel dual coating drug-eluting stents could inhibit the proliferation of local intestinal tissue around the stents. However, in vivo studies illustrated that the intestinal stents gradually degraded in rabbit model within 12 *** the degradation rate of the stent was faster than expected in rabbits, the support performance of the scaffold requires further improvement.

关键词： Mg alloys Degradability Intestinal stent Poly(L-lactide)/paclitaxel coating

Cooperative Channel Assignment for VANETs Based on Dual Reinforcement Learning

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Computers, Materials & Continua 2021年第2期66卷 2127-2140页

作者： Xuting duan Yuanhao Zhao Kunxian zheng Daxin Tian Jianshan Zhou Jian Gao Beijing Advanced Innovation Center for Big Data and Brain Computing Beijing100191China School of Transportation Science and Engineering Beihang UniversityBeijing100191China Department of Engineering and Design University of SussexBrightonBN19RHUK Research Institute of Highway Ministry of Transport Beijing100088China

Dynamic channel assignment(DCA)is significant for extending vehicular ad hoc network(VANET)capacity and mitigating ***,the un-known global state information and the lack of centralized control make channel assignment performances a challenging task in a distributed vehicular direct communication *** our preliminary field test for communication under V2X scenario,we find that the existing DCA technology cannot fully meet the communication performance requirements of *** order to improve the communication performance,we firstly demonstrate the feasibility and potential of reinforcement learning(RL)method in joint channel selection decision and access fallback adaptation design in this ***,a dual reinforcement learning(DRL)-based cooperative DCA(DRL-CDCA)mechanism is ***,DRL-CDCA jointly optimizes the decision-making behaviors of both the channel selection and back-off adaptation based on a multi-agent dual reinforcement learning ***,nodes locally share and incorporate their individual rewards after each communication to achieve regional consistency *** results show that the proposed DRL-CDCA can better reduce the one-hop packet delay,improve the packet delivery ratio on average when compared with two other existing mechanisms.

关键词： Vehicular ad hoc networks reinforcement learning dynamic channel assignment

Facile synthesis of novel fluorinated thieno[2,3-d]pyrimidine derivatives containing 1,3,4-thiadiazole

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Chinese Chemical Letters 2012年第5期23卷 549-552页

作者： Xin Jian Song zheng Chao duan Yu Shao Xing Gao Dong Key Laboratory of Biological Resources Protection and Utilization of Hubei Province Hubei University for NationalitiesEnshi 445000China Medical School Hubei University for NationalitiesEnshi 445000China

A series of novel fluorinated thieno[2,3-d]pyrimidine derivatives incorporating 1,3,4-thiadiazole were synthesized by a facile microwave-assisted procedure,including the cyclization of 2-aminothiophene-3-carbonitrile with trifluoroacetic acid,chlorination and nucleophilic substitution *** protocol offered such advantages as mild reaction conditions,short reaction time, simple puritication and good *** structures of the products were characterized by ~1H NMR,MS,elemental analysis and Xray diffraction.

关键词： Thieno[2.3-d]pyrimidine 1 3 4-Thiadiazole Trifluoromethyl Microwave-assisted synthesis

Seepage field distribution and water inflow laws of tunnels in water-rich regions

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Journal of mountain Science 2022年第2期19卷 591-605页

作者： LI zheng CHEN Zi-quan HE Chuan MA Chun-chi duan Chao-ran School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China Chongqing University Industrial Technology Research Institute Chongqing 401329China Chongqing City Construction Investment(Group)Co. LtdChongqing 400023China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China School of Civil Engineering Changzhou Institute of TechnologyChangzhou 213032China

Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the accompanying disturbances to the ecological environment have become the main problems that affect the structural safety of tunnels in water-rich *** this paper,a tunnel seepage model testing system was used to conduct experiments of the grouting circle and primary support with different permeability *** influences of the supporting structures on the water inflow laws and the distribution of the water pressure in the tunnel were *** the decrease in the permeability coefficient of the grouting circle or the primary support,the inflow rate of water into the tunnel showed a non-linear decreasing *** comparison,the water inflow reduction effect of grouting circle was much better than that of primary *** the increase of the permeability coefficient of the grouting ring,the water pressure behind the primary lining increases gradually,while the water pressure behind the grouting ring ***,the grouting of surrounding rock during the construction of water-rich tunnel can effectively weaken the hydraulic connection,reduce the influence range of seepage,and significantly reduce the decline of ***,the seepage tests at different hydrostatic heads and hydrodynamic heads during tunnel operation period were also *** the hydrostatic head decreased,the water pressure at each characteristic point decreased approximately linearly,and the water inflow rate also had a gradual downward *** the action of hydrodynamic head,the water pressure had an obvious lagging effect,which was not conducive to the stability of the supporting structures,and it could be mitigated by actively regulating the drainage *** with the hydrostatic head,the hydrodynamic head could change the real-time rate of water inflow to the tunnel and broke the dynamic balance between the water pressure and water inflow

关键词： Water-rich tunnel Seepage field distribution Water inflow law Construction period Operation period