共查询到18条相似文献,搜索用时 78 毫秒
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HRP引发酚类与淀粉接枝共聚物的制备及结构性能表征 总被引:2,自引:0,他引:2
降解淀粉和酚类在辣根过氧化物酶(HRP)/H2O2的催化作用下进行自由基接枝共聚反应,制备了淀粉和酚类接枝共聚物。研究了淀粉降解程度、酚类单体配比、HRP用量、反应温度和pH对接枝改性淀粉结构与性能的影响。研究结果表明,用α-淀粉酶降解后的淀粉15与12g间苯三酚(PG)和20g对羟基苯磺酸钠(HBS)在5mg HRP/H2O2引发体系下,在30℃及pH值为7.0时反应5h制备的酚类与淀粉接枝共聚物具有较好的性能,其水溶液的表面张力为26.6mN/m,所鞣制皮革收缩温度(Ts)达到了78℃。用FT-IR、1 H NMR、UV-Vis和GPC等方法对产物的化学结构进行了表征。 相似文献
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不同真空处理时间对SOD、HRP和α-AMY活性的影响 总被引:2,自引:2,他引:0
将超氧化物歧化酶(SOD)、辣根过氧化物酶(HRP)和淀粉酶(α-AMY)置于真空环境中不同时间,测试真空对超氧化物歧化酶、辣根过氧化物酶和α-淀粉酶活性的影响.不同真空处理时间对酶蛋白活性有不同影响,在处理时间为3~15 min范围,超氧化物歧化酶、辣根过氧化物酶和α-淀粉酶相对活性基本上都呈降低的趋势.因此,在离子注入生物效应的研究中,应该考虑真空对生物体所产生的影响. 相似文献
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对羟基苯甲酸(PHBA)与对氨基苯磺酸(SAA)在辣根过氧化物酶(HRP)/H2O2催化下进行自由基共聚反应,合成了PHBA-SAA共聚物。研究了反应温度、体系pH、单体用量、HRP用量、H2O2滴加时间和反应时间对聚合反应的影响。在去离子水150mL与KH2PO4-K2HPO4缓冲溶液50mL组成的溶液中,当PHBA与SAA物质的量之比为2∶1且二者的用量为0.15mol、HRP用量为5mg、17g30%H2O2滴加时间为2h、体系的pH值稳定在8.0时,在30℃下反应3.5h得到了PHBA与SAA的共聚产物,其物质的量产率约为98%。通过FTIR、NMR和GPC表征了产物结构。提出了PHBA与SAA自由基聚合反应机理。应用结果表明,该产物具有助染、复鞣等性能。 相似文献
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建立了可用于被动式微混合器设计的宏微建模方法,利用分离变量法建立用于求解直通道内样品浓度分布的宏模型,采用宏模型计算微混合器的各段直通道内样品的浓度分布.运用有限元方法数值求解复杂的混合单元内样品的浓度分布,通过数值拟合和插值,交换宏模型与数值求解的计算结果.经过反复迭代,实现被动式微混合器的系统级求解.采用数控铣削在聚甲基丙烯酸甲脂(PMMA)平板上加工微通道,用热键合的方法实现微混合器盖片与基片的封装.在微混合器入口,输入3种不同浓度的荧光素钠盐溶液,形成样品浓度的准正态分布.采用激光诱导荧光观察和分析样品的混合效果.通过对比数值仿真和实验测试结果,验证了宏微建模计算方法的准确性. 相似文献
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在辣根过氧化物酶(HRP)/H2O2的催化作用下间苯二酚(RE)和3,5-二羟基苯甲酸(DBA)通过自由基共聚反应生成酚类共聚物,研究了RE和DBA的配比对共聚物鞣剂性能的影响,用FT-IR、1 HNMR、13C NMR、GPC和UV等方法对酚类共聚物的分子结构进行了表征。水溶液中HRP/H2O2催化自由基聚合反应的显著特征是共聚物的相对分子质量容易控制,酚类聚合物苯环直接相连,结构内存在较大的共轭体系。应用结果表明酚类聚合物具有较好的鞣制效果,鞣制后的皮革收缩温度(Ts)达到了78.6℃,复鞣皮革非常柔软丰满。 相似文献
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介绍利用热导气相色谱分析仪测定氢气、氖气和氩气三元混合气中各组分含量的分析方法,试验结果计算表明,该分析方法能够满足电子芯片保护气产品质量检测的要求。 相似文献
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辣根过氧化物酶固定化载体材料的研究进展 总被引:2,自引:1,他引:1
酶的固定化是酶工程领域的一个重要分支,而固定化酶的性能在很大程度上取决于载体材料的性质,因此研制开发性能优异的固定化载体材料成为了固定化酶技术最为活跃的研究方向之一.辣根过氧化物酶(HRP)是一类在生物传感器、有机合成和废水处理等领域有着广泛应用的酶制剂.人们对其固定化进行了大量的研究,取得了丰硕的成果,开发出了许多性能优异的载体材料.结合固定化HRP的应用,从天然高分子材料、合成高分子聚合物、无机材料及复合材料等方面综述了HRP固定化载体材料的研究进展.结果表明,载体材料的发展能有效地改善固定化酶的性能,并在扩大其应用范围的同时还可能带来固定化酶技术上的突破. 相似文献
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利用计算流体力学和数字图像处理技术,研究"Y"型通道式微混合器的结构及混合性能,分析了混合器结构尺寸和流动条件对混合过程的影响.数值模拟结果表明,在混合通道入口夹角为60°、通道宽度为200μm、注入速度为0.02 m/s的流动条件下,可以取得比较满意的混合效果.利用数值模拟对比了扭曲通道混合器、导流块和直通道结构对混合过程的影响,结果表明使用导流块可以显著提高混合效果.依照模拟计算结果,设计并用MEMS工艺制作了双侧壁有内肋块的通道式微混合器,并进行了流体混合实验,观测了混合过程.拍摄混合实验图像,对比标准浓度-图像灰度关系曲线后识别出拍摄点混合指数.识别计算的结果也证实了所设计混合器性能上的优越性.最后对实验结果误差进行了分析,说明了误差来源并给出了相应的改进措施. 相似文献
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制备了基于负载辣根过氧化氢酶(HRP)的介孔二氧化硅(MS)粒子的酶场效应晶体管(ENFET)用来检测过氧化氢浓度的生物传感器。不同孔径的MS粒子被用作固定酶的载体构造ENFET,显著改善了酶的固定量。用负载HRP的MS粒子修饰于离子敏场效应管的栅极制成的过氧化氢敏ENFET灵敏度较传统的直接固定HRP的ENFET有显著的提高。对不同孔径的MS粒子研究发现,扩孔的MS粒子的性能更好,同时还讨论了缓冲液浓度和pH值的影响。另外,由于在MS粒子表面组装了5个复层的聚电解质,生物传感器的稳定性良好。 相似文献
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Patric Baumann Mariana Spulber Ozana Fischer Anja Car Wolfgang Meier 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(17)
In order to mimic cell organelles, artificial nanoreactors have been investigated based on polymeric vesicles with reconstituted channel proteins (outer membrane protein F) and coencapsulated enzymes horseradish peroxidase (HRP) along with a crowding agent (Ficoll or polyethylene glycol) inside the cavity. Importantly, the presence of macromolecules has a strong impact on the enzyme kinetics, but no influence on the integrity of vesicles up to certain concentrations. This particular design allows for the first time the determination of HRP kinetics inside nanoreactors with crowded milieu. The values of the Michaelis–Menten constant (K m) measured for HRP in a confined space (encapsulated in nanoreactors) in the absence of macromolecules are ≈50% lower than in free conditions, and the presence of a crowding agent results in a further pronounced decrease. These results clearly suggest that activities of enzymes in confined spaces can be tuned by varying the concentrations of crowding compounds. The present investigation represents an advance in nanoreactor design by considering the influence of environmental factors on enzymatic performance, and it demonstrates that both encapsulation and the presence of a crowding environment increase the enzyme‐substrate affinity. 相似文献
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Choo-Yee Ting Helmi Zakariah Fadzilah Kamaludin Darryl Lin-Wei Cheng Nicholas Yu-Zhe Tan Hui-Jia Yee 《计算机、材料和连续体(英文)》2021,67(1):835-848
Ever since the COVID-19 pandemic started in Wuhan, China, much research work has been focusing on the clinical aspect of SARS-CoV-2. Researchers have been leveraging on various Artificial Intelligence techniques as an alternative to medical approach in understanding the virus. Limited studies have, however, reported on COVID-19 transmission pattern analysis, and using geography features for prediction of potential outbreak sites. Predicting the next most probable outbreak site is crucial, particularly for optimizing the planning of medical personnel and supply resources. To tackle the challenge, this work proposed distance-based similarity measures to predict the next most probable outbreak site together with its magnitude, when would the outbreak likely to happen and the duration of the outbreak. The work began with preprocessing of 1365 patient records from six districts in the most populated state named Selangor in Malaysia. The dataset was then aggregated with population density information and human elicited geography features that might promote the transmission of COVID-19. Empirical findings indicated that the proposed unified decision-making approach outperformed individual distance metric in predicting the total cases, next outbreak location, and the time interval between start dates of two similar sites. Such findings provided valuable insights for policymakers to perform Active Case Detection. 相似文献
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A. Kermad S. Sam N. Ghellai K. Khaldi N. Gabouze 《Materials Science and Engineering: B》2013,178(18):1159-1164
In this study, horseradish peroxidase enzyme (HRP) was covalently immobilized on porous silicon (PSi) surface using multistep strategy. First, acid terminations were generated on hydrogenated PSi surface by thermal hydrosilylation of undecylenic acid. Then, the carboxyl-terminated monolayer was transformed to active ester (succinimidyl ester) using N-hydroxysuccinimide (NHS) in the presence of the coupling agent N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide (EDC). Subsequently, the enzyme was anchored on the surface via an amidation reaction. The structure of the PSi layers was observed by scanning electron microscopy (SEM). Infrared spectroscopy (FTIR) and contact angle measurements confirmed the efficiency of the modification at each step of the functionalization. Cyclic voltammetry was recorded using the HRP-modified PSi as working electrode. The results show that the enzymatic activity of the immobilized HRP is preserved and in the presence of hydrogen peroxide, the enzyme oxidizes phenolic molecules which were subsequently reduced at the modified-PSi electrode. 相似文献