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缩醛化葡聚糖的制备及其酸响应性
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作者 徐玉笛 马胜 汤朝晖 《功能高分子学报》 CAS CSCD 北大核心 2019年第5期633-639,共7页
通过缩醛键将正丁基、异丁基、环己基、叔丁基等疏水基团分别引入到葡聚糖主链上,制备了一系列酸敏感性缩醛化葡聚糖。通过核磁分析、紫外-可见光谱测试了缩醛化葡聚糖的结构和酸响应性。结果表明,制得的缩醛化葡聚糖具有相同羟基取代度... 通过缩醛键将正丁基、异丁基、环己基、叔丁基等疏水基团分别引入到葡聚糖主链上,制备了一系列酸敏感性缩醛化葡聚糖。通过核磁分析、紫外-可见光谱测试了缩醛化葡聚糖的结构和酸响应性。结果表明,制得的缩醛化葡聚糖具有相同羟基取代度,且全部为非环状缩醛结构,其酸响应性与缩醛β位的碳原子有关,正丁基修饰的葡聚糖需要更低的pH才能水解,叔丁基修饰的葡聚糖具有更灵敏的酸响应性。 展开更多
关键词 葡聚糖 缩醛 酸响应性
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具有酸响应性的染料木素脂质体制备
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作者 李强 范伟伟 杨洋 《荆楚理工学院学报》 2018年第4期43-47,共5页
目的:制备具有酸响应性的染料木素脂质体并研究其性能。方法:采用酯化和酰胺化反应,将胆固醇和聚乙二醇单甲醚(m PEG)通过苯甲酰亚胺键连接,制备出具有酸响应功能的胆固醇-苯甲酰亚胺-聚乙二醇,采用1H NMR对其结构进行表征;然后利用氢... 目的:制备具有酸响应性的染料木素脂质体并研究其性能。方法:采用酯化和酰胺化反应,将胆固醇和聚乙二醇单甲醚(m PEG)通过苯甲酰亚胺键连接,制备出具有酸响应功能的胆固醇-苯甲酰亚胺-聚乙二醇,采用1H NMR对其结构进行表征;然后利用氢化大豆卵磷脂包载染料木素,并采用胆固醇-苯甲酰亚胺-聚乙二醇和穿膜肽Stearyl-R8进行修饰,最终制备出具有酸响应性的染料木素脂质体;采用透射电镜(TEM)和动态光散射(DLS)对制备的脂质体尺寸进行了表征,并通过酸性环境下粒径的变化考察了脂质体的酸响应性。结论:制备的染料木素脂质体尺寸为115. 39 nm,粒径分布均匀(PDI=0. 134),对酸性环境表现出良好的响应性。 展开更多
关键词 脂质体 染料木素 酸响应性
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ZIF-8纳米载体的制备及负载黄芩素性能研究 被引量:4
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作者 时慧 汪河滨 +1 位作者 连培涵 杨玲 《塔里木大学学报》 2021年第4期29-35,共7页
本研究采用溶剂法制备了酸响应性沸石咪唑酯金属有机骨架-8(ZIF-8)纳米材料,通过扫描电子显微镜(SEM)、X射线多晶衍射仪(XRD)、红外光谱(FTIR)对制备的样品进行形态结构表征,并探讨了在不同温度下分别以乙酸锌、硝酸锌和2-甲基咪唑为原... 本研究采用溶剂法制备了酸响应性沸石咪唑酯金属有机骨架-8(ZIF-8)纳米材料,通过扫描电子显微镜(SEM)、X射线多晶衍射仪(XRD)、红外光谱(FTIR)对制备的样品进行形态结构表征,并探讨了在不同温度下分别以乙酸锌、硝酸锌和2-甲基咪唑为原料,不同反应摩尔比对制备ZIF-8的影响。然后以无水乙醇为介质,利用溶剂扩散法负载黄芩素(BA)制备BA@ZIF-8载药体系。结果表明:制备出的ZIF-8形貌良好、尺寸合适、能够负载黄芩素,载药率为14.89%,包封率为74.45%。而且与单一药物BA相比,BA@ZIF-8具有保持药物稳定性和延缓释放的特点,且具备明显的酸响应性。 展开更多
关键词 黄芩素 金属-有机骨架 酸响应性
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具有pH-响应性的聚天冬氨酸类载药胶束的制备和释放能力研究 被引量:2
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作者 于树芳 王铮 +3 位作者 伍国琳 王亦农 高辉 马建标 《高分子学报》 SCIE CAS CSCD 北大核心 2012年第4期427-432,共6页
通过大分子引发剂ω-氨基-α-甲氧基聚乙二醇引发N-羧基-α-氨基环内酸酐开环聚合和水合肼侧基改性,制备了一系列聚乙二醇-聚氨基酸类三嵌段共聚物.其中聚氨基酸链段包括具有酰肼基的聚天冬氨酸衍生物(PAHy),以及疏水性的聚丙氨酸链段.... 通过大分子引发剂ω-氨基-α-甲氧基聚乙二醇引发N-羧基-α-氨基环内酸酐开环聚合和水合肼侧基改性,制备了一系列聚乙二醇-聚氨基酸类三嵌段共聚物.其中聚氨基酸链段包括具有酰肼基的聚天冬氨酸衍生物(PAHy),以及疏水性的聚丙氨酸链段.引入具有pH响应性的腙键键合阿霉素,利用键合阿霉素与游离阿霉素之间的π-π叠合作用,在聚合物自组装形成胶束过程中通过化学键合+物理包埋的方式充分负载药物.该胶束以聚丙氨酸链段为核心,以PEG链段为冠层,以PAHy链段为包裹药物的壳层.载药胶束的粒径在170 nm左右.研究不同pH值条件下载药胶束的药物释放能力,随环境pH值的降低药物的释放速率显著增加. 展开更多
关键词 聚天冬氨 腙键 阿霉素 pH-响应
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Physiological Responses of Yixing Lily Leaf and Bulb to Drought Stress 被引量:8
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作者 魏传斌 张萍 +1 位作者 覃芸 张凤银 《Agricultural Science & Technology》 CAS 2010年第1期33-35,58,共4页
[Objective]To explore an effective method for evaluating drought resistance of Yixing lily and provide a reference for selecting drought-resistant Yixing lily varieties. [Method]Through artificial simulation of drough... [Objective]To explore an effective method for evaluating drought resistance of Yixing lily and provide a reference for selecting drought-resistant Yixing lily varieties. [Method]Through artificial simulation of drought stress environment,the changes of physiological indexes,such as content of proline,malonaldehyde,and reducing sugar in Yixing lily leaf and bulb were observed,when soil water content changed. [Result]The response to drought stress of the Yixing lily leaf was greater than that of the bulb,and the content of the proline and malonaldehyde was higher than that of the reducing sugar. [Conclusion]The leaves as an appropriate material for evaluation and analysis on drought resistance can better reflect the physiological responses of Yixing lily to drought stress. And the content of the malonaldehyde and that of proline are preferable indexes. 展开更多
关键词 Yixing lily Drought stress MALONALDEHYDE PROLINE Reducing sugar Response
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Optimization on the Conversion of Bamboo Shoot Shell to Levulinic Acid with Environmentally Benign Acidic Ionic Liquid and Response Surface Analysis 被引量:8
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作者 周存山 余筱洁 +2 位作者 马海乐 何荣海 Saritporn Vittayapadung 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第5期544-550,共7页
Levulinic acid(LA) has been identified as a promising green,biomass derived platform chemical.Response surface analysis(RSA) with a four-factor-five-level central composite design(CCD) was applied to optimize th... Levulinic acid(LA) has been identified as a promising green,biomass derived platform chemical.Response surface analysis(RSA) with a four-factor-five-level central composite design(CCD) was applied to optimize the hydrolysis conditions for the conversion of bamboo(Phyllostachys Praecox f.preveynalis) shoot shell(BSS) to LA catalyzed with ionic liquid [C4mim]HSO4.The effects of four main reaction parameters including temperature,time,C[C4mim]HSO4(initial [C4mim]HSO4 concentration) and XBSS(initial BSS intake) on the hydrolysis reaction for yield of LA were analyzed.A quadratic equation model for yield of LA was established and fitted to the data with an R2 of 0.9868,and effects of main factors and their corresponding relationships were obtained with RSA.Model validation and results of CCD showed good correspondence between actual and predicted values.The analysis of variance(ANOVA) of the results indicated that the yield of LA in the range studied was significantly(P&lt;0.05) affected by the four factors.The optimized reaction conditions were as follows:temperature of 145 ℃,time of 103.8 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2.04%(by mass),respectively.A high yield [(71±0.41)%(by mol),triplicate experiment] was obtained at the optimum conditions of temperature of 145 ℃,time of 104 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2%(by mass),which obtained from the real experiments,concurred with the model prediction [73.8%(by mol) based on available C6 sugars in BSS or 17.9%(by mass) based on the mass of BSS],indicating that the model was adequate for the hydrolysis process. 展开更多
关键词 levulinic acid ionic liquid response surface analysis bamboo shoot shell
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Indoleamine 2,3-dioxygenase (IDO) is essential for dendritic cell activation and chemotactic responsiveness to chemokines 被引量:12
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作者 Shih Ling HWANG Nancy Pei-Yee CHUNG +1 位作者 Jacqueline Kwai-Yi CHAN Chen-Lung Steve LIN 《Cell Research》 SCIE CAS CSCD 2005年第3期167-175,共9页
Indoleamine 2, 3-dioxygenase (IDO) is a rate-limiting enzyme for the tryptophan catabolism. In human and murine cells, IDO inhibits antigen-specific T cell proliferation in vitro and suppresses T cell responses to fet... Indoleamine 2, 3-dioxygenase (IDO) is a rate-limiting enzyme for the tryptophan catabolism. In human and murine cells, IDO inhibits antigen-specific T cell proliferation in vitro and suppresses T cell responses to fetal alloantigens during murine pregnancy. In mice, IDO expression is an inducible feature of specific subsets of dendritic cells (DCs), and is important for T cell regulatory properties. However, the effect of IDO and tryptophan deprivation on DC func- tions remains unknown. We report here that when tryptophan utilization was prevented by a pharmacological inhibitor of IDO, 1-methyl tryptophan (1MT), DC activation induced by pathogenic stimulus lipopolysaccharide (LPS) or inflam- matory cytokine TNF-α was inhibited both phenotypically and functionally. Such an effect was less remarkable when DC was stimulated by a physiological stimulus, CD40 ligand. Tryptophan deprivation during DC activation also regu- lated the expression of CCR5 and CXCR4, as well as DC responsiveness to chemokines. These results suggest that tryptophan usage in the microenvironment is essential for DC maturation, and may also play a role in the regulation of DC migratory behaviors. 展开更多
关键词 Indoleamine 2 3-dioxygenase (IDO) dendritic cells ACTIVATION T cell TRYPTOPHAN chemokine.
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A pH-responsive zinc(Ⅱ) metalated porphyrin for enhanced photodynamic/photothermal combined cancer therapy 被引量:2
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作者 Pingpine Liang Hao Tang +6 位作者 Rui Gu Lei Xue Dapeng Chen Wenjun Wang Zhou Yang Weili Si Xiaochen Dong 《Science China Materials》 SCIE EI CSCD 2019年第8期1199-1209,共11页
The acidic tumor microenvironment is triggered by glycolysis in hypoxic condition, which can motivate the pHresponsive system to build certain triggers for efficiently tumor-targeted phototherapy. Additionally, the me... The acidic tumor microenvironment is triggered by glycolysis in hypoxic condition, which can motivate the pHresponsive system to build certain triggers for efficiently tumor-targeted phototherapy. Additionally, the metalated porphyrin structures are widely studied in biomedical applications due to the favorable properties of high singlet oxygen quantum yield as well as strong fluorescence imaging ability. Herein, a pH-responsive zinc(II) metalated porphyrin(P-4) was designed and synthesized for amplifying cancer photodynamic/photothermal therapy with excellent fluorescence quantum yield(67.4%), superb singlet oxygen quantum yield(84.3%) and desired photothermal conversion efficiency(30.0%). In vitro, the self-assembled P-4 nanoparticles can specifically target to lysosome subcellular site and realize protonated process of dibutaneaminophenyl(DBAP) groups with high photo toxicity. Under single 660 nm laser illumination, the tumor can be ablated completely with no side effects in vivo. This work demonstrates that the p H-responsive P-4 nanoparticles provide a new avenue for highly efficient cancer combination therapy. 展开更多
关键词 PH-RESPONSIVE PORPHYRIN NIR absorbance photodynamic therapy photothermal therapy
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Bio-inspired shape-memory structural color hydrogel film 被引量:3
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作者 Yu Wang Zhuohao Zhang +3 位作者 Hanxu Chen Han Zhang Hui Zhang Yuanjin Zhao 《Science Bulletin》 SCIE EI CSCD 2022年第5期512-519,M0004,共9页
Structural colors,derived from existing natural creatures,have aroused widespread attention in the materials regulation for different applications.Here,inspired by the color adjusting mechanism of hummingbird,we prese... Structural colors,derived from existing natural creatures,have aroused widespread attention in the materials regulation for different applications.Here,inspired by the color adjusting mechanism of hummingbird,we present a novel shape-memory structural color hydrogel film by introducing shape memory polymers(SMPs)into synthetic inverse opal scaffold structure.The excellent flexibility as well as the inverse opal structure of the hydrogel films imparts them with stable stretchability and brilliant structural colors.Benefiting from the transient structural anisotropy of copolymers,the hybrid films are possessed with shape-morphing behaviors capability.Based on the shape transformations and color responsiveness performance,we have demonstrated diverse structural color actuators with complex shapes for different tasks.Notably,as the photothermal responsive graphene quantum dots were integrated into the hydrogel,the hybrid films could also be endowed with the feature of light-controlled reversible deformation with synchronous structural color variation.These features demonstrate that the presented shape-memory structural color hydrogel film is valuable for soft robotics with multifunctions of sensing,communication and disguise. 展开更多
关键词 BIO-INSPIRED Structural color SHAPE-MEMORY HYDROGEL RESPONSIVE
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