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Increased MAD2L2 expression predicts poor clinical outcome in Colon Adenocarcinoma 被引量:1
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作者 HAOTONG SUN HEYING WANG +5 位作者 XIN LI YANJIE HAO jun ling HUAN WANG FEIMIAO WANG FANG XU 《BIOCELL》 SCIE 2023年第3期607-618,共12页
Background:Colon adenocarcinoma(COAD)is the second leading cause of cancer death worldwide thus,identification of COAD biomarkers is critical.Mitotic Arrest Deficient 2 Like 2(MAD2L2)is a key factor in mammalian DNA d... Background:Colon adenocarcinoma(COAD)is the second leading cause of cancer death worldwide thus,identification of COAD biomarkers is critical.Mitotic Arrest Deficient 2 Like 2(MAD2L2)is a key factor in mammalian DNA damage repair and is highly expressed in many malignant tumors.This is a comprehensive study of MAD2L2 expression,its diagnostic value,prognostic analysis,potential biological function,and impact on the immune system of patients with COAD.Methods:Gene expression,clinical relevance,prognostic analysis,diagnostic value,GO/KEGG cluster analysis,data obtained from TCGA,and bioinformatics statistical analysis were performed using the R package.Immune responses to MAD2L2 expression in COAD were analyzed using TIMER.The expression of MAD2L2 in HCT116 cells induced by the inflammatory factor TNF-αwas detected using Western blot.Results:Our results underscore the clinical diagnostic value and potential biological significance of MAD2L2 in patients with COAD.A high level of MAD2L2 expression has been found in COAD and correlated with tumor status and colon polyps.ROC curve analysis showed that MAD2L2 expression has high diagnostic value in COAD.Analysis of immune infiltration results showed that MAD2L2 expression was positively correlated with neutrophil levels.The western blot results demonstrated that MAD2L2 was dose-dependently present with TNF-α.GO/KEGG revealed that MAD2L2 overexpressed and coexpressed genes were mostly involved in biological functions,including hypoxia response,response to reduced oxygen levels,mitochondrial translation elongation,and other processes.Conclusion:MAD2L2 as a new COAD biomarker contributes to our understanding of how alterations in gene expression and the immunological environment contribute to the development of colon cancer.Following further investigation,MAD2L2 may prove to be a viable target factor for clinical diagnosis and therapy of COAD. 展开更多
关键词 MAD2L2 COAD Poor prognosis Immune infiltration TCGA
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Effect of sitagliptin combined with Yiqi yangyin huoxue decoction on clinical efficacy and hemorheology in early diabetic nephropathy 被引量:1
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作者 jun ling Yan-Hua Yang 《World Journal of Diabetes》 SCIE 2023年第9期1412-1421,共10页
BACKGROUND Early diabetic nephropathy(DN)is a complication of diabetes mellitus.It mainly affects kidney microvessels and glomerular function,and its timely and effective treatment is critical for early DN.However,the... BACKGROUND Early diabetic nephropathy(DN)is a complication of diabetes mellitus.It mainly affects kidney microvessels and glomerular function,and its timely and effective treatment is critical for early DN.However,the effects of treatments comprising simple Western medicine are not optimal.With the promotion and implementation of integrated Chinese and western medicine treatments,remarkable results have been achieved for many diseases.To this end,we explored the clinical efficacy of integrated traditional Chinese and western medicines for the treatment of early DN.AIM To investigate the effect of sitagliptin tablets combined with Yiqi yangyin huoxue decoction on clinical efficacy and hemorheology in patients with early DN.METHODS Through a retrospective analysis,123 patients with early DN were admitted to the endocrinology clinic of the Changzhou NO.7 People’s Hospital from January 2021 to October 2022 and were selected as study subjects.After rigorous screening,100 patients with early DN were enrolled.The control group(CG,n=50)and the observation group(OG,n=50)were divided according to the treatment method.The CG were treated with sitagliptin,and the OG were treated with sitagliptin plus the Yiqi yangyin huoxue decoction.Both groups were treated for 3 mo.For both groups,the baseline data and clinical efficacy were compared,and changes in blood glucose levels,lipid levels,renal function,and hematological indicators before(T0)and after(T1)treatment were assessed.RESULTS The total effective rate for the OG was 94.00%and that of the CG was 80.00%(P<0.05).After treatment(T1),the levels of fasting blood glucose,2 h postprandial glucose,total cholesterol,triacylglycerol,and low-density lipoprotein cholesterol in OG patients were obviously lower than those in the CG(P<0.05),and cystatin C,homocysteine,urinary microalbumin,and blood creatinine values in OG patients were also obviously lower than those in the CG(P<0.05);erythrocyte deposition,plasma viscosity,whole blood high shear viscosity,and whole blood low shear viscosity were markedly lower in OG patients than in the CG(P<0.05).CONCLUSION Sitagliptin combined with Yiqi yangyin huoxue decoction has a remarkable effect when used to treat patients with early DN.Further,it is helpful in improving hemorheological indices and controlling disease progression. 展开更多
关键词 SITAGLIPTIN Yiqi yangyin huoxue decoction Early diabetic nephropathy Renal function Clinical effects HEMORHEOLOGY
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公立医院人力资源管理转型实践研究 被引量:2
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作者 张红 李晋辉 +3 位作者 王杏蕊 任舜禹 俊领 何玥 《中国卫生产业》 2022年第15期220-223,共4页
公立医院高质量发展的战略背景下,人力资源的转型实践成为医院管理的重要议题。研究基于公立医院综合改革的要求,对医院人力资源转型的价值要义进行提炼总结,梳理归纳了医院人力资源管理转型的内在机制,得出医院人力资源管理转型的实现... 公立医院高质量发展的战略背景下,人力资源的转型实践成为医院管理的重要议题。研究基于公立医院综合改革的要求,对医院人力资源转型的价值要义进行提炼总结,梳理归纳了医院人力资源管理转型的内在机制,得出医院人力资源管理转型的实现路径——构建基于医院人力资源管理的“三支柱”模型,并对人力资源的未来发展趋势进行展望,以期为人力资源管理转型的理论与实践探索提供参考与借鉴。 展开更多
关键词 公立医院 人力资源管理 三支柱模型 转型实践
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Fault prediction method for nuclear power machinery based on Bayesian PPCA recurrent neural network model 被引量:6
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作者 jun ling Gao-jun Liu +2 位作者 Jia-Liang Li Xiao-Cheng Shen Dong-Dong You 《Nuclear Science and Techniques》 SCIE CAS CSCD 2020年第8期13-23,共11页
Early fault warning for nuclear power machinery is conducive to timely troubleshooting and reductions in safety risks and unnecessary costs. This paper presents a novel intelligent fault prediction method, integrated ... Early fault warning for nuclear power machinery is conducive to timely troubleshooting and reductions in safety risks and unnecessary costs. This paper presents a novel intelligent fault prediction method, integrated probabilistic principal component analysis(PPCA), multi-resolution wavelet analysis, Bayesian inference, and RNN model for nuclear power machinery that consider data uncertainty and chaotic time series. After denoising the source data, the Bayesian PPCA method is employed for dimensional reduction to obtain a refined data group. A recurrent neural network(RNN) prediction model is constructed, and a Bayesian statistical inference approach is developed to quantitatively assess the prediction reliability of the model. By modeling and analyzing the data collected on the steam turbine and components of a nuclear power plant, the results of the goodness of fit, mean square error distribution, and Bayesian confidence indicate that the proposed RNN model can implement early warning in the fault creep period. The accuracy and reliability of the proposed model are quantitatively verified. 展开更多
关键词 Fault prediction Nuclear power machinery Steam turbine Recurrent neural network Probabilistic principal component analysis Bayesian confidence
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Thrombospondin peptide ABT-898 inhibits inflammation and angiogenesis in a colitis model 被引量:2
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作者 Linda S Gutierrez jun ling +2 位作者 Derek Nye Konstantina Papathomas Catherine Dickinson 《World Journal of Gastroenterology》 SCIE CAS 2015年第20期6157-6166,共10页
AIM: To evaluate the efficacy of the improvedthrombospondin mimetic peptide ABT-898 in a murine model of ulcerative colitis. METHODS: The dextran sodium sulfate(DSS) was used for the induction of colitis in both TSP-1... AIM: To evaluate the efficacy of the improvedthrombospondin mimetic peptide ABT-898 in a murine model of ulcerative colitis. METHODS: The dextran sodium sulfate(DSS) was used for the induction of colitis in both TSP-1 deficient(TSP-1-/-) and wild type(WT) mice during 7 d. While mice were receiving the DSS dissolved in the drinking water, the ABT-898 peptide was dissolved in sterile 5% glucose solution and delivered using mini pumps subcutaneously implanted. Plasma samples were analyzed for interleukin(IL)-6 by ELISA assay and colonic tissues were harvested, fixed and processed for histological evaluation. Immunohistochemistry using antibodies for the detection of CD31 and MECA in endothelial cells was performed. Inflammation was graded in colonic sections and the number of microvessels in each lesion was assessed. Activation of signal transducer and activator of transcription 3(STAT3) in colonic samples was quantified by immunohistochemistry and Western blotting using antibodies against total STAT3 and phosphorylated STAT3(p STAT3)(Ser727).RESULTS: Treatment with ABT-898 considerably diminished the inflammatory response in WT and TSP-1-/- mice(P < 0.0001 in both groups vs control). Identification of blood vessels highlighted by CD31/MECA immunohistochemistry, showed significantly reduced vessel counts in colitic lesions of WT and TSP-1-/- mice treated with ABT898(TSP-1-/- controls/TSP-1-/- treated, P = 0.0002; WT controls/WT treated, P = 0.0005). Consistently, IL-6 was significantly diminished in plasma samples of TSP-1-/- and WT treated with the peptide when compared to the control mice(P = 0.0002 and P = 0.0148, respectively). p STAT3 positive cells were quantified in WT and TSP-1-/- treated with ABT-898. A significant decrease in positive cells for p STAT3 was observed in treated mice(TSP-1-/- controls/TSP-1-/- treated, P = 0.0089; WT/WT treated, P = 0.0110). These results were confirmedby Western blotting analyses showing lower levels of p STAT3 in colitic lesions from mice treated with the peptide ABT-898.CONCLUSION: These findings indicate that the new peptide ABT-898 ameliorates inflammation and angiogenesis and might be a therapeutic alternative in IBD and inflammatory diseases. 展开更多
关键词 THROMBOSPONDIN 1 ABT-898 ABT-510 ANGIOGENESIS Inflammatory bowel disease Dextransodium sulfate MODEL INTERLEUKIN-6 STAT-3
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浅谈武汉市液化石油气储配站压力管道的定期检验 被引量:1
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作者 聂思皓 凌俊 +2 位作者 陈忠 朱义 黄璞 《石化技术》 CAS 2022年第1期113-114,共2页
液化石油气储配站内的压力管道起着承载储配站各功能区之间介质流转的重要作用,其安全是连续生产的重要保证。定期检验是保证管道长期运行和安全生产的有力措施,所以,管道的定期检验工作非常重要。结合实际工作经验,介绍了武汉市液化石... 液化石油气储配站内的压力管道起着承载储配站各功能区之间介质流转的重要作用,其安全是连续生产的重要保证。定期检验是保证管道长期运行和安全生产的有力措施,所以,管道的定期检验工作非常重要。结合实际工作经验,介绍了武汉市液化石油气储配站内压力管道定期检验的主要项目,讨论了需要注意的问题。 展开更多
关键词 液化石油气储配站 压力管道 定期检验
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Rare Earth Complex Initiated Ring-Opening Polymerization of 2,2-Dimethyltrimethylene Carbonate
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作者 jun ling Yi Feng ZHANG Zhi Quan SHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第1期41-42,共2页
The ring opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) initiated by single component of tris(2,6-di-tert-butyl-4-methylphenoxo) lanthanide (Ln(OAr)(3)) is reported. The initiators are highly activ... The ring opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) initiated by single component of tris(2,6-di-tert-butyl-4-methylphenoxo) lanthanide (Ln(OAr)(3)) is reported. The initiators are highly active to the polymerization and give high molecular weight polymers. (HNMR)-H-1 spectra and DSC measurement suggest the polymerization is free of decarboxylation. Mechanism study shows that the monomer insertion is via the break of acyl-oxygen bond of DTC. 展开更多
关键词 tris(2 6-di-tert-butyl-4-methylphenoxo) lanthanide 2 2-dimethyltrimethylene carbonate ring-opening polymerization
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STILL LIFE The Golden Lion Winner
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作者 jun ling 《China & The World Cultural Exchange》 2006年第11期36-37,共2页
At the 63rd Venice International ,Film Festival concluded on September 9, 2006, the Chinese film "Still Life" directed by Jia Zhangke won the Golden Lion Award as the best film.Jia's documentary "The East" also w... At the 63rd Venice International ,Film Festival concluded on September 9, 2006, the Chinese film "Still Life" directed by Jia Zhangke won the Golden Lion Award as the best film.Jia's documentary "The East" also won the Italian Documentaries Association Award and the "Open 2006" Award. 展开更多
关键词 《三峡好人》 威尼斯 国际电影节 2006年 贾樟柯 导演 金狮奖 故事简介 电影评论
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Random Terpolymer of Carbon Dioxide,Butadiene and Epoxides:Synthesis,Functionalization and Degradability
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作者 Zi Wang Wuyi Zheng +3 位作者 Sicong Yue Kaihao Chen jun ling Xufeng Ni 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第14期1630-1636,共7页
The utilization of carbon dioxide(CO_(2))as a C1 feedstock is consistently attractive,especially in the preparation of sustainable polymeric materials.In this contribution,a terpolymer of CO_(2),1,3-butadiene(BD)and e... The utilization of carbon dioxide(CO_(2))as a C1 feedstock is consistently attractive,especially in the preparation of sustainable polymeric materials.In this contribution,a terpolymer of CO_(2),1,3-butadiene(BD)and epoxide is synthesized by scandium triflate catalyzed cationic ring-opening copolymerization ofα-ethylidene-δ-vinyl-δ-valerolactone(EVL),an intermediate derived from CO_(2)and BD,with epoxides.The obtained terpolymer with a CO_(2)content of 22 mol%has a number-average molecular weight(M_(n))up to 7.8 kg/mol and a dispersity(Đ)of 2.4.The reactivity ratios of EVL and cyclohexene oxide(CHO)are determined as 0.01 and 1.07,respectively,suggesting random characteristic of the terpolymer.The preserved C=C double bonds from BD allow for the further modification of the terpolymer by photoinitiated crosslinking.The yielded networks are fluorescent and degradable.This method offers enhanced versatility to the synthesis and additional functionalization of CO_(2)-based polymers. 展开更多
关键词 Ring-opening polymerization Copolymerization Carbon dioxide BUTADIENE Scandium triflate Fluorescence
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Green LED irradiation promotes the quality of cabbage through delaying senescence and regulating glucosinolate metabolism
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作者 郭峰 周宏胜 +5 位作者 胡花丽 张映曈 凌军 刘雪松 罗淑芬 李鹏霞 《Food Quality and Safety》 SCIE CAS CSCD 2024年第1期190-200,共11页
Light-emitting diode(LED)irradiation can affect postharvest vegetable and fruit shelf life and nutritional quality.In this study,11 kinds of glucosinolates(GLS)and 6 types of GLS breakdown products were identified in ... Light-emitting diode(LED)irradiation can affect postharvest vegetable and fruit shelf life and nutritional quality.In this study,11 kinds of glucosinolates(GLS)and 6 types of GLS breakdown products were identified in cabbage leaves.To investigate the effects of LED irradiation on quality and GLS metabolism,postharvest cabbage was irradiated with 25μmol/(m2·s)green LED(GL)light at room temperature for 12 d.The dark condition and natural light were used as controls.GL irradiation inhibited the respiration rate and the accumulation of malondialdehyde,and maintained higher cabbage sensory score,chlorophyll content,and antioxidant enzyme activities,thus extending its postharvest shelf life.Additionally,GL irradiation promoted GLS profile accumulation,including glucoraphanin,glucoiberin,gluconapin,gluconasturtiin,glucobrassicin,and sinigrin,which could have resulted from upregulated expression of the transcription factors MYB28 and MYB51,and the key genes involved in GLS biosynthesis(CYP83A1,CYP83B1,ST5b,and UGT74B1).Furthermore,GLS degradation was promoted by this treatment during the late stage of shelf life,as higher myrosinase activity and relative MYR and ESM expression levels were found in treated cabbage leaves,resulting in higher isothiocyanate(ITC)and indole-3-carbinol contents after day 6.Therefore,GL irradiation was beneficial for cabbage preservation. 展开更多
关键词 CABBAGE light SENESCENCE glucosinolate metabolism.
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Effect of Molecular Weight of PEG Soft Segments on Photo-stimulated Selfhealing Performance of Coumarin Functionalized Polyurethanes 被引量:7
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作者 jun ling Min-zhi Rong 章明秋 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2014年第10期1286-1297,共12页
Polyurethanes consisting of tri-functional homopolymer of hexamethylene diisocyanate (tri-HDI) and polyethylene glycol (PEG) are synthesized, in which photo-reversible coumarin moieties act as pendant groups. Acco... Polyurethanes consisting of tri-functional homopolymer of hexamethylene diisocyanate (tri-HDI) and polyethylene glycol (PEG) are synthesized, in which photo-reversible coumarin moieties act as pendant groups. Accordingly, the polyurethanes can be repeatedly self-healed under UV lights at room temperature by taking advantages of the photodimerization and photocleavage habits of coumarin. Molecular weight of the soft segment, PEG, is found to be closely related to the healing performance of the polyurethanes. Lower molecular weight PEG that corresponds to higher initial coumarin concentration in the polymer is critical for obtaining higher healing efficiency in the case of the first healing action. Nevertheless, it does not guarantee high reversibility of the photo-remendability during the repeated healing events. In contrast, the polyurethane with moderate molecular weight PEG has achieved balanced performance. Reaction kinetics is less important for the healing effect. 展开更多
关键词 Polyurethanes SELF-HEALING COUMARIN PHOTOCHEMISTRY Reversibility.
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MAD2L2 overexpression attenuates the effects of TNF-α-induced migration and invasion capabilities in colorectal cancer cells
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作者 HAOTONG SUN HEYING WANG +5 位作者 YANJIE HAO XIN LI jun ling HUAN WANG FEIMIAO WANG FANG XU 《BIOCELL》 SCIE 2024年第9期1311-1322,共12页
Background:Colorectal cancer is a major global health concern,exacerbated by tumor necrosis factor-alpha(TNF-α)and its role in inflammation,with the effects of Mitotic Arrest Deficient 2 Like 2(MAD2L2)in this context... Background:Colorectal cancer is a major global health concern,exacerbated by tumor necrosis factor-alpha(TNF-α)and its role in inflammation,with the effects of Mitotic Arrest Deficient 2 Like 2(MAD2L2)in this context still unclear.Methods:The colorectal carcinoma cell lines HCT116 and SW620 were exposed to TNF-αfor a period of 24 h to instigate an inflammatory response.Subsequent assessments were conducted to measure the expression of inflammatory cytokines,the activity within the p38 mitogen-activated protein kinase(p38 MAPK)and Phosphoinositide 3-Kinase/AKT Serine/Threonine Kinase pathway(PI3K/AKT)signaling cascades.Transcriptome sequencing and subsequent integrative analysis with the Cancer Genome Atlas(TCGA)program database revealed a significant downregulation of the key factor MAD2L2.Enhancement of MAD2L2 expression was facilitated via lentiviral vector-mediated transfection.The influence of this overexpression on TNF-α-prompted inflammation,intracellular signaling pathways,and the migratory and invasive behaviors of the colorectal cancer cells was then scrutinized.Results:TNF-αtreatment significantly increased the expression of Interleukin-1 beta(IL-1β)and Interleukin-6(IL-6),activated the MAPK p38 and PI3K/AKT signaling pathways,and enhanced cell migration and invasion.A decrease in MAD2L2 expression was observed following TNF-αtreatment.However,overexpression of MAD2L2 reversed the effects of TNF-α,reducing IL-1βand IL-6 levels,attenuating PI3K/AKT pathway activation,and inhibiting cell migration and invasion.Conclusions:Overexpression of MAD2L2 attenuates the pro-inflammatory effects of TNF-α,suggesting that MAD2L2 plays a protective role against TNF-α-induced migration and invasion of colorectal carcinoma cells.Therefore,MAD2L2 holds potential as a therapeutic target in the treatment of colorectal cancer. 展开更多
关键词 Colorectal cancer TNF-α MAD2L2 Migration Invasion
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Facile Synthesis of Functional Poly (ε-caprolactone) via Janus Polymerization 被引量:4
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作者 Huan Qiu Zhe-Ning Yang jun ling 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2019年第9期858-865,共8页
Functionalized aliphatic polyesters attract increasing attentions as biocompatible and biodegradable polymers with broad applications in biological science. In this contribution, we propose a facile and controllable s... Functionalized aliphatic polyesters attract increasing attentions as biocompatible and biodegradable polymers with broad applications in biological science. In this contribution, we propose a facile and controllable synthetic technique for functional poly(ε-caprolactone)(PCL) via Janus polymerization, which comprises cationic ring-opening copolymerization (ROP) of ε-caprolactone (CL) with 3,3-bis(chloromethyl)oxacyclobutane (CO) and (coordinated) anionic ROP of CL at a single propagating chain by rare earth metal triflates (RE(OTf)3)and propylene oxide, thus generating block copolymers in one step. The compositions of the copolymers of poly(CLb-(CL-r-CO)) can be modulated by various RE(OTf)3. Scandium triflate catalyzes Janus polymerization to yield the copolymers containing the highest CO contents among all the RE(OTf)3 catalysts used with complete conversion of CL. The chlorine in CO repeating units is ready to be transferred into azide group which affords the modification sites to react with 9-ethynyl-9-fluorenol and mPEG-alkyne, respectively, via copper(I)-catalyzed azide-alkyne cycloaddition reaction with quantitative conversions of azides, as confirmed by FTIR analyses. According to NMR and SEC analyses, copolymers (PCC-g-PEG) bearing a homo-PCL block and a PEG-grafted block of poly(CO-co-CL) demonstrate well-defined chemical structures. The investigations on thermal properties reveal the strong phase separation between PCL and PEG blocks. The amphiphilic PCC-g-PEG is able to sei住assemble into micelles in aqueous solution while cylindrical and lamellar morphologies are observed in bulk. We provide an efficient protocol to synthesize functional PCL combining onestep Janus polymerization and precise post-polymerization click reaction. 展开更多
关键词 JANUS POLYMERIZATION FUNCTIONAL poly(ε-caprolactone) Poly(3 3-bis(chloromethyl)oxacyclobutane) RING-OPENING POLYMERIZATION Rare earth metal catalysts
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Synthesis and self-assembly of poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)and their oxidation-sensitive polymersomes 被引量:4
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作者 Yangwei Deng Hui Chen +3 位作者 Xinfeng Tao Sylvain Trepout jun ling Min-Hui Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第7期1931-1935,共5页
Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-... Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-NTA)initiated by amino-terminated PEG.The self-assemblies of three PEG-b-PMeSPG copolymers with different PMeSPG block lengths were first prepared by nanoprecipitation method using THF and DMF,respectively,as the organic solvent,and their morphologies were studied by Cryo-EM and DLS.To prepare polymersomes loaded with glucose oxidase(GOx),double emulsion method followed by extrusion treatment was employed.The oxidation-responsive disruption of polymersomes was achieved upon the introduction of glucose because of the oxidants generated insitu by GOx/glucose. 展开更多
关键词 Polypeptoid SELF-ASSEMBLY POLYMERSOME Oxidation-responsive Glucose oxidase
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Mechanism of Janus Polymerization: A DFT StudyFig. S3 Energy profiles of anionic polymerization in Stage I under B3LYP/6-31G(d,p)(blue) and B3LYP/aug-cc-p VTZ//B3LYP/6-31G(d,p)(red). Scheme S1. Propagation process of CL/THF on cationic side in Stage I of J 被引量:2
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作者 Tian-Wen Bai Xu-Feng Ni +1 位作者 jun ling Zhi-Quan Shen 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2019年第10期990-994,I0004,共6页
Janus polymerization is featured as a combination of cationic and anionic growing ends in one living polymer chain. In the copolymerization of THF and CL catalyzed by lutetium triflates and initiated by propylene oxid... Janus polymerization is featured as a combination of cationic and anionic growing ends in one living polymer chain. In the copolymerization of THF and CL catalyzed by lutetium triflates and initiated by propylene oxide, three stages are identified by kinetic study including(1) fast cationic polymerization with slow anionic one,(2) fast anionic polymerization with dormant cationic one, and(3)reactivation of cationic polymerization with coupling of anionic and cationic chain ends. In this work, density functional theory(DFT)calculation is employed to investigate the reaction details of ionic polymerization and dormancy. A “tripedal crow” configuration is proposed to illustrate the unique high-coordinated ligand exchange configuration in anionic polymerization in different stages. The trigger of dormancy is determined as chain structures rather than concentration of triflate anion according to both calculation and experimental results. 展开更多
关键词 Rare earth metal catalysts RING-OPENING POLYMERIZATION Ionic POLYMERIZATION Reaction MECHANISM Quantum chemicalcomputation
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Controllable preparation and microwave absorption properties of shape anisotropic Fe_(3)O_(4) nanobelts 被引量:3
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作者 Jialiang Pan Rujing Zhang +5 位作者 jun ling Min Wang Zechen Li Zhen Zhen Limin He Hongwei Zhu 《Journal of Materiomics》 SCIE EI 2021年第5期957-966,共10页
To substantially prevent electromagnetic threatens,microwave absorbing materials(MAMs)are required to eliminate surplus electromagnetic waves.As a typical MAM,Fe_(3)O_(4) particles with complex permittivity and permea... To substantially prevent electromagnetic threatens,microwave absorbing materials(MAMs)are required to eliminate surplus electromagnetic waves.As a typical MAM,Fe_(3)O_(4) particles with complex permittivity and permeability have been widely applied due to the coexistence of magnetic loss and dielectric loss.However,the necessary high mass fraction significantly limited its applications,thus Fe_(3)O_(4) nanostructures have been extensively investigated to overcome this problem.In this work,uniform Fe_(3)O_(4) nanobelts were prepared by electrospinning and two-step thermal treatment.By controlling the composition and viscosity of the electrospinning precursor solution,Fe_(3)O_(4) nanobelts with tunable lateral sizes(200 nme1 mm)were obtained.The samples with low content(only 16.7 wt%)Fe_(3)O_(4) exhibited wide maximum effective absorbing bandwidths(EAB)over 3 GHz,and Fe_(3)O_(4) nanobelts with smaller lateral sizes showed a maximum EAB of 4.93 GHz.Meanwhile,Fe_(3)O_(4) nanobelts with smaller lateral sizes presented superior reflection loss properties,the lowest reflection loss reached-53.93 dB at 10.10 GHz,while the maximum EAB was up to 2.98 GHz.The excellent microwave reflection loss of Fe_(3)O_(4) nanobelts was contributed to the enhanced synergistic effect of magnetic loss,dielectric loss,and impedance matching,originated from the hierarchically cross-linked networks and shape anisotropies.This study could broaden the practical applications of magnetic absorbers,and provided an approach for the development of shape anisotropic magnetic materials. 展开更多
关键词 Fe_(3)O_(4) NANOBELTS Shape anisotropy Microwave absorption Reflection loss
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Synthesis of Well-defined Poly(tetrahydrofuran)-b-Poly(a-amino acid)s via Cationic Ring-opening Polymerization (ROP) of Tetrahydrofuran and Nucleophilic ROP of N-thiocarboxyanhydrides 被引量:2
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作者 Peng Zhou Xuan-Geng Dai +1 位作者 Jie Kong jun ling 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2021年第6期702-708,I0006,共8页
The synthesis of block copolymers of poly(tetrahydrofuran)-b-poly(α-amino acid)(PTHF-b-PAA)is challenging since it is difficult to combine the two blocks produced via different/conflicting ring-opening polymerization... The synthesis of block copolymers of poly(tetrahydrofuran)-b-poly(α-amino acid)(PTHF-b-PAA)is challenging since it is difficult to combine the two blocks produced via different/conflicting ring-opening polymerization(ROP)mechanisms.In this contribution,the cationic ROP of THF is catalyzed by rare-earth triflate[RE(OTf)3]and terminated by 2-(t-butyloxycarbonyl-amino)ethanol(BAE).After the deprotection of t-butyloxycarbonyl(Boc)group,the chain end of PTHF is quantitatively changed to amino group which thereafter initiates the nucleophilic ROP ofα-amino acid N-thiocarboxyanhydrides(NTAs).Both polymerizations are well controlled,generating PTHF and PAA segments with designable molecular weights(MWs).PTHF-b-polylysine(PTHF-b-PLys)and PTHF-b-polysarcosine(PTHF-b-PSar)are obtained with MWs between 8.6 and 28.7 kg/mol.The above amphiphilic diblock copolymers form micelles in water.PTHF40-b-PSar32 acts as a surfactant to stabilize oil-in-water emulsions.Both segments of PTHF-b-PAA are biocompatible and promising in the biomedical application. 展开更多
关键词 ANHYDRIDE polymerization CARBONYL
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Donor-Acceptor Oligomers and Polymers Composed of Benzothiadiazole and 3-Hexylthiophene: Effect of Chain Length and Regioregularity 被引量:1
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作者 Jintu Wang Huaiying Ye +4 位作者 Hongjiao Li Chongyu Mei jun ling Weishi Li Zhiquan Shen 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2013年第11期1367-1379,共13页
A series of donor-acceptor oligomer OBTThn (n = 1- 7) and polymer PBTThl and PBTTh2 composed of al- ternative 2,1,3-benzothiadiazole and 3-hexylthiophene have been designed and synthesized for the purpose of in- ves... A series of donor-acceptor oligomer OBTThn (n = 1- 7) and polymer PBTThl and PBTTh2 composed of al- ternative 2,1,3-benzothiadiazole and 3-hexylthiophene have been designed and synthesized for the purpose of in- vestigation on the effect of chain length and side-chain regioregularity on their basic properties and photovoltaic performance. In the OBTThn oligomers and PBTThl polymer, all the hexyl side chains on thienyl units orient to- ward the same direction. Upon elongation of the chain length, the intramolecular charge transfer (ICT) absorption band in solution gradually redshifts from 398 nm for OBTThl to 505 nm for OBTThT, then to 512 nm for PBTThl polymer. Meanwhile, the HOMO energy level increases from -5.45 eV (OBTTh0 to -5.08 eV (OBTThT) and -5.09 eV (PBTThl), and the LUMO energy level decreases from -3.11 eV (OBTTh0 to -3.30 eV (OBTThT) and -3.33 eV (PBTThl), thus giving a smaller and smaller energy bandgap for higher oligomers and polymers. Theo- retical calculation suggests straight line-like backbone geometry for this series of oligomers and polymer. On the other hand, polymer PBTTh2 possesses a different side-chain regioregularity, in which every two neighbor hexyl side chains are arranged in different orienting direction. It is theoretically suggested to have curved line-like back- bone geometry. In solution, it shows similar photophysical and electrochemical properties as PBTThl. However in film state, it displays a less redshift in the ICT band as refer to that in solution than PBTThl. In combination with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), these oligomers and polymers were used as donor material to fabricate organic bulk heterojunction solar cells. Again, chain length-dependent device photovoltaic performance was observed. The device based on OBTTh4 showed a power conversion efficiency of 0.16%, while it increased to 0.36% and 0.49% for the devices based on OBTTh6 and PBTThb respectively. However, the side-chain regio- regularity has less influence on the device photovoltaic output since the device based on PBTTh~ displayed an effi- ciency of 0.52%, comparable to that of PBTThl. 展开更多
关键词 conjugated polymers organic solar cells REGIOREGULARITY DONOR-ACCEPTOR OLIGOMERS
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Janus Polymerization:A One-Shot Approach towards Amphiphilic Multiblock Poly(ester-acetal)s Directly from 1,3-Dioxolane withε-Caprolactone 被引量:1
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作者 Huan Qiu Ting Shen +4 位作者 Zhening Yang Feng Wu Xiaohong Li Yingfeng Tu jun ling 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2022年第6期705-712,共8页
Janus polymerization consists of anionic and cationic ring opening polymerizations(AROP and CROP)at the two ends of a single propagating polymer chain,followed by a self-triggered chain extension generating multiblock... Janus polymerization consists of anionic and cationic ring opening polymerizations(AROP and CROP)at the two ends of a single propagating polymer chain,followed by a self-triggered chain extension generating multiblock copolymers(MBCPs)in one step.In the contribution,Janus polymerization by Tm(OTf)_(3) or Er(OTf)_(3) catalyst with an epoxy initiator is applied to synthesize MBCPs of semi-crystalline poly(ε-caprolactone)(PCL)blocks from coordinated AROP and poly(1,3-dioxolane-co-ε-caprolactone)(P(DO-co-CL))blocks from CROP of DO with CL.Meanwhile,amorphous random copolymers[P(DO-r-CL)]are synthesized as control by employing other rare earth triflates[RE(OTf)_(3),RE=Y,Nd,Gd and Lu]as catalysts or in the absence of an initiator via CROP.On account of the distinguishable chemical structures and thermal properties between Janus MBCPs and cationic random copolymers,Janus features are confirmed including the CROP and AROP at a single propagating chain.The resultant amphiphilic copolymers self-assemble to nanoparticles in aqueous solution with designable diameters with the corresponding ratios of hydrophilic and hydrophobic seg-ments.MBCPs exhibit good shape memory properties with appropriate deformation temperature close to human body's,providing a prospect on the applications in biomedical devices. 展开更多
关键词 Janus polymerization Ring-opening polymerization Multiblock copolymers Homogeneous catalysis(?)Lanthanides
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Visualized Degradation of CO_(2)-Based Unsaturated Polyesters toward Structure-Controlled and High-Value-Added Fluorophores 被引量:2
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作者 Bo Song Tianwen Bai +5 位作者 Dongming Liu Rong Hu Dan Lu Anjun Qin jun ling Ben Zhong Tang 《CCS Chemistry》 CAS 2022年第1期237-249,共13页
In comparing with traditional polymer degradation toward unknown or unvalued products(i.e.,downcycling),new methods to degrade polymers into monomers or high-value-added materials(i.e.,upcycling)are preferable for sus... In comparing with traditional polymer degradation toward unknown or unvalued products(i.e.,downcycling),new methods to degrade polymers into monomers or high-value-added materials(i.e.,upcycling)are preferable for sustainable developments.In this work,CO_(2)-based linear and cross-linked unsaturated polyesters,that is,poly(alkynoate)s,were successfully degraded by benzamidine into diols and high-value-added pyrimidone or imidazolone derivatives through controlled reaction conditions.The degradation process could be visualized under UV light via gradually increased luminescent intensity of the reaction mixtures and fluorescence patterns could be generated through microcontact printing of the stamp on the thin films of poly(alkynoate)s.Moreover,the pyrimidone derivatives could be applied in bioimaging and inhibiting bacteria,and the imidazolone derivatives could be used for the detection and recovery of gold(III)ions from electronic waste and serve as the fluorescent sensor to detect in situ-generated amines from food spoilage.Thus,this work presents a visualized and high value productselective degradation to solve the end-of-life issue of polymers. 展开更多
关键词 visualized degradation N-heterocyclic compounds aggregation-induced emission microcontact printing gold enrichment
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