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近年来,卟啉及金属卟啉的超分子化学迅速发展成为现代化学的一个重要分支。卟啉及金属卟啉组装体在光、电、纳米等新型功能材料中有广泛的应用,已引起了人们的极大兴趣。本文就卟啉及金属卟啉组装体的功能、性质及应用前景进行了综述。 相似文献
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本研究探究了功能磁共振成像技术评估药物难治性颞叶癫痫患者的记忆、语言及认知功能的应用价值.选取148例药物难治性颞叶癫痫患者作为实验组,另选取148例健康者作为对照组参与测试,两组患者均行功能磁共振成像技术检查记忆、语言及认知功能,分析功能磁共振成像技术的评估效果.结果 表明,动词生成语言任务模式下,功能磁共振成像结果... 相似文献
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李莉莉陈少华张思灯石玉元毛宇辰成艳华陈文萍周哲孙宾朱美芳 《高分子通报》2013,(10):12-20
通过纳米材料与纤维基体的复合制备出聚合物基纳米复合材料,使其兼具纳米材料的功能性和聚合物的易加工性。本文综述了纳米复合阻燃纤维、纳米复合抗紫外纤维、纳米复合抗菌纤维和纳米复合导电纤维材料及纳米复合功能纤维的研究现状,包括纳米材料的改性、设计构筑及其复合聚合物、复合材料纺丝和功能性评价。提出未来聚合物基纳米复合纤维的几个主要发展方向:纳米材料的结构设计及可控制备与功能复合技术、成纤高聚物纳米改性技术,以及纳米复合纤维后整理加工技术;开发多功能复合产业用纤维,以及利用纳米技术开发战略性新兴产业用功能纤维;智能纤维的开发研究;纳米复合功能纤维及纺织品的生态安全性及系统评价。 相似文献
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微量元素硒的抗癌作用 总被引:1,自引:0,他引:1
对硒在恶性肿瘤的防治及其作用机理进行了总结和讨论,硒通过调节机体免疫功能、介入致癌物的代谢、抑制癌细胞生长及抗过氧化作用等发挥防癌和抗癌功能。另外,硒对白血病的治疗引起了人们的重视。 相似文献
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Two of the most challenging problems that scientists and researchers face when they want to experiment with new cutting‐edge algorithms are the time‐consuming for encoding and the difficulties for linking them with other technologies and devices. In that sense, this article introduces the artificial organic networks toolkit for LabVIEW? (AON‐TL) from the implementation point of view. The toolkit is based on the framework provided by the artificial organic networks technique, giving it the potential to add new algorithms in the future based on this technique. Moreover, the toolkit inherits both the rapid prototyping and the easy‐to‐use characteristics of the LabVIEW? software (e.g., graphical programming, transparent usage of other softwares and devices, built‐in programming event‐driven for user interfaces), to make it simple for the end‐user. In fact, the article describes the global architecture of the toolkit, with particular emphasis in the software implementation of the so‐called artificial hydrocarbon networks algorithm. Lastly, the article includes two case studies for engineering purposes (i.e., sensor characterization) and chemistry applications (i.e., blood–brain barrier partitioning data model) to show the usage of the toolkit and the potential scalability of the artificial organic networks technique. © 2015 Wiley Periodicals, Inc. 相似文献
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Deciphering a Nanocarbon‐Based Artificial Peroxidase: Chemical Identification of the Catalytically Active and Substrate‐Binding Sites on Graphene Quantum Dots
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Hanjun Sun Andong Zhao Dr. Nan Gao Dr. Kai Li Prof. Jinsong Ren Prof. Xiaogang Qu 《Angewandte Chemie (International ed. in English)》2015,54(24):7176-7180
The design and construction of efficient artificial enzymes is highly desirable. Recent studies have demonstrated that a series of carbon nanomaterials possess intrinsic peroxidase activity. Among them, graphene quantum dots (GQDs) have a high enzymatic activity. However, the catalytic mechanism remains unclear. Therefore, in this report, we chose to decipher their peroxidase activity. By selectively deactivating the ketonic carbonyl, carboxylic, or hydroxy groups and investigating the catalytic activities of these GQD derivatives, we obtained evidence that the ? C?O groups were the catalytically active sites, whereas the O?C? O? groups acted as substrate‐binding sites, and ? C? OH groups can inhibit the activity. These results were corroborated by theoretical studies. This work should not only enhance our understanding of nanocarbon‐based artificial enzymes, but also facilitate the design and construction of other types of target‐specific artificial enzymes. 相似文献
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Thomas Hauch Fenger Mikael Bols 《Journal of inclusion phenomena and macrocyclic chemistry》2011,69(3-4):397-402
Cyclodextrin based oxidases, with a ketone as functional group are well known as good artificial enzyme mimics (Fenger et al. Org Biomol Chem 7:933?C943; Marinescu and Bols Angew Chem Int Ed 45:4590?C4593; Bjerre et al. Eur J Org Chem 704?C710; Marinescu et al. J Am Chem Soc 127:17578?C17579). We here report a series of modified cyclodextrins, having aldehydes as functional groups. The aldehyde based artificial enzymes have, in most cases, better catalysis than the ketones, because of their powerful covalent binding of hydrogen peroxide. Among the modified cyclodextrins studied are mono and di aldehydes on the 6 positions, with or without methylated hydroxyl groups. The aldehyde functionality was also introduced close to the secondary side, by attaching ethoxy-2-al or propoxy-3-al to the 2 position. The modified cyclodextrins showed excellent enzymatic activity towards oxidation of different aminophenols, and 4-methoxy benzyl alcohol with hydrogen peroxide as a stoichiometric oxidant. Rate enhancements up to 4,600 were achieved for oxidation of 4-methoxy benzyl alcohol, where as oxidation of amines gave rate enhancements up to 3,400. The artificial oxidases catalyses oxidations under enzymatic conditions (water, pH 7, 25 °C), following Michaelis?CMenten kinetics. To confirm the enzyme activity, inhibition studies with sodium naphthalene-2-sulfonate were carried out. These studies showed competitive inhibition of the enzymes, verifying the cyclodextrins enzyme like character. 相似文献
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This study aimed to evaluate the inhibitory effects of herbal extracts on caries-related bacteria, glucan and biofilm in?vitro. Sensitive tests of bacteria were carried out by broth dilution method on a 96-microwell plate. Glucan inhibition tests were carried out using the phenol sulphate method. A minimum biofilm inhibitory concentration (MBIC) test was performed in an artificial mouth model. The results of the MBIC of agents were 8, 16 and 32?mg?mL(-1) for eugenol, tannic acid and magnolol, respectively. For the results of glucan inhibition tests, over 63%, 28% and 27% inhibition occurred on insoluble glucan syntheses of Streptococcus sobrinus for eugenol, magnolol and tannic acid, respectively. Over 46%, 16% and 13% inhibition on soluble glucan syntheses for eugenol, magnolol and tannic acid, respectively, were also observed. In conclusion, the inhibition of eugenol on glucan is essential for the biofilm inhibition effect on caries-related biofilm in an artificial mouth model in?vitro. 相似文献
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DNA与其靶向分子相互作用研究进展 总被引:59,自引:0,他引:59
DNA与其靶向分子相互作用的研究不仅对阐述一些抗肿瘤、抗病毒药物及致癌物的作用机理,而且对进一步指导人工核酸酶的合成及DNA高级结构研究等方面的工作都具有重要意义.本文着重评述了近年来不同结构类型的DNA靶向分子与DNA相互作用研究方面的进展. 相似文献
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Mei Wen Jiang Ouyang Chuanwan Wei Hui Li Wansong Chen You‐Nian Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17586-17593
Current cancer therapy is seriously challenged by tumor metastasis and recurrence. One promising solution to these problems is to build antitumor immunity. However, immunotherapeutic efficacy is highly impeded by the immunosuppressive state of the tumors. Here a new strategy is presented, catalytic immunotherapy based on artificial enzymes. Cu2?xTe nanoparticles exhibit tunable enzyme‐mimicking activity (including glutathione oxidase and peroxidase) under near‐infrared‐II (NIR‐II) light. The cascade reactions catalyzed by the Cu2?xTe artificial enzyme gradually elevates intratumor oxidative stress to induce immunogenic cell death. Meanwhile, the continuously generated oxidative stress by the Cu2?xTe artificial enzyme reverses the immunosuppressive tumor microenvironment, and boosts antitumor immune responses to eradicate both primary and distant metastatic tumors. Moreover, immunological memory effect is successfully acquired after treatment with the Cu2?xTe artificial enzyme to suppress tumor relapse. 相似文献
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Dendrimer technology has enabled us to build macromolecules with nanosized defined structures. By introducing unsymmetrical
patched structures in dendrimers, sophisticated artificial receptors exhibiting nanoscale substrate recognition can be obtained.
In this review article, our recent studies on molecular recognition by porphyrin dendrimers with patched structures are summarized.
Three topics are presented: (1) oligopeptide-patched dendrimers as a nanoscale receptor of cytochrome c protein; (2) pocket dendrimers as a nanoscale receptor for bimolecular guest accommodation; and (3) energy transfer in unsymmetrical
dendrimers. These dendrimers nicely mimic proteins and enzymes, and also act as photofunctional artificial receptors, in which
porphyrin’s strong photoabsorption and intense fluorescence signals can respond sensitively to the substrate binding. 相似文献
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Toshi Nagata 《Research on Chemical Intermediates》2014,40(9):3183-3198
Quinones are essential components in many biological systems, notably in photosynthesis. This is largely due to the characteristic proton-coupled redox chemistry of quinones. This review article overviews the use of quinones in studies on artificial photosynthesis, as one-electron electron acceptors, reversible proton/electron carriers, and replacements for sacrificial oxidant and reductants in photosynthetic chemical conversion. Topics included are the early attempts on intramolecular photoinduced electron transfer involving quinones, subsequent reactions after photoinduced electron transfer between pigments and quinones, photochemistry in molecular assemblies containing quinones, and photochemical quinone/hydroquinone interconversion. 相似文献
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Manfred Mutter Stphane Vuilleumier 《Angewandte Chemie (International ed. in English)》1989,28(5):535-554
Advances in methodology in both chemistry and molecular biology allow us to take a fresh look at protein science. Chemical synthesis of peptides and site-directed mutagenesis are now standard research tools, paving the way for the construction of new proteins with tailor-made structural and functional properties. The decisive hurdle on the way lies not in the synthesis of the molecules proper but rather in a better understanding of the complex folding pathways of polypeptide chains into spatially well-defined structures. Can the chemist use his synthetic tools to bypass the notorious “folding problem?” In this article, we present a new approach developed in our laboratory, which opens a chemical route to artificial proteins with predetermined three-dimensional structures, allowing a first step towards the synthesis of new proteins with functional properties. 相似文献