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Schwekendiek K Kobarg H Daumlechner L Sönnichsen FD Lindhorst TK 《Chemical communications (Cambridge, England)》2011,47(33):9399-9401
Glycothymidines were designed and synthesized as a new class of functional glycomimetics in which a photochemical [2+2] cycloaddition of the thymine moiety induces structural changes of carbohydrate presentation. To test if photodimerisation of these glycothymidines is feasible within an array of molecules, the photochemical reaction was investigated using NMR and NMR diffusion experiments in solution as well as in the supramolecular context of detergent micelles that mimic cellular membranes. 相似文献
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传统的抗肿瘤药物大多不具有选择性,在临床治疗中产生了严重的毒副作用。核酸适配体是一种小分子核酸,能够与靶标高亲和性、高特异性地结合。选择与癌症发生发展过程密切相关的生物标记物为靶标进行SELEX过程筛选出的核酸适配体自身可作为药物,也可与药物、siRNA、纳米粒等结合构成靶向给药体系,该体系能靶向作用于特定的肿瘤细胞,降低对正常细胞的毒性,用药量显著降低,药效提高。本文综述了近年来核酸适配体直接作为抗肿瘤药物、药物载体、siRNA载体以及作为纳米材料靶向剂构成多元复合靶向给药体系在肿瘤靶向治疗领域的研究进展。 相似文献
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Wen-Hu Bao Zheng Wang Xiao Tang Yun-Fu Zhang Jia-Xi Tan Qin Zhu Zhong Cao Ying-Wu Lin Wei-Min He 《中国化学快报》1990,30(12):2259-2262
A simple and clean protocol for the synthesis of various alkyl and (hetero)aryl S-thiocarbamates was established. The usage of in situ generated hydroxide as both an oxygen source and hydrogen source as well as biomass-derived 2-methyltetrahydrofuran as a green reaction medium, the avoidance of phosphorus-containing reductant, and the generation of harmless water and nitrogen as the side-products have given the present method atom-economy and environmental friendliness. 相似文献
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Using the direct x-ray fluorescence determination of Ba, Sr, Zr, and Zn in soils as an example, it was shown that the nature of the test material as well as the biogeochemical properties of the analytes should be taken into account for improving the reliability of analytical data in determining trace elements in soils. 相似文献
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S. Mohammad. Haji-Saeid M.H. Sampa A. Safrany S. Sabharwal N. Ramamoorthy 《Radiation Physics and Chemistry》2012,81(8):1040-1044
Radiation treatment, or a combination of radiation with conventional biological–chemical–physical processes, can help in the remediation of contaminated surfaces and in combating industrial chemical effluents and air pollution. The use of ionizing radiation as a powerful tool for inactivation of microbes is a valuable option to address likely threats from biohazard contamination that could be introduced either deliberately or inadvertently into areas where the public are exposed to, as well as for treatment of volatile organic compounds and similar hazardous chemical agents is an emerging development in tackling harmful pollutants. The role of the IAEA has been crucial both in supporting the development of local capabilities as well as in fostering international cooperation due to the multidisciplinary expertise required for achieving sustainable benefits. The IAEA is implementing Coordinated Research Projects, (CRP) thematic topical reviews of issues and challenges involved, and Technical Cooperation (TC) assistance in establishing and maintaining infrastructure in the MS. This paper will give an insight into the above mentioned IAEA activities, with examples of successes achieved through CRPs, as well as challenges on the road for broader dissemination of radiation processing technology for environmental remediation. 相似文献
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聚吡咯以其制备简单、掺杂可逆、环境友好、导电率高、比电容大、具有良好的成膜性而备受关注。特别是在作为超级电容器、二次电池等换能设备电极材料领域中前景广阔。文章简略地介绍了超级电容器的双电层电容和法拉第赝电容产生的机理,概述了近年来聚吡咯与金属氧化物、炭材料等通过化学法、电化学法以及界面化学法等新型手段制备聚吡咯电极的研究进展。 相似文献
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Timerbaev AR 《Journal of capillary electrophoresis》1998,5(5-6):185-192
Recent advances in capillary electrophoresis methodology to improve the detection sensitivity for inorganic ions are briefly reviewed. Specifically discussed are current developments of nonabsorbance-based CE detectors and on-capillary enrichment techniques as well as some possible future perspectives. 相似文献
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Conventional thermal and chemical treatments used in food preservation have come under scrutiny by consumers who demand minimally processed foods free from chemical agents but microbiologically safe. As a result, antimicrobial peptides (AMPs) such as bacteriocins and nisin that are ribosomally synthesised by bacteria, more prominently by the lactic acid bacteria (LAB) have appeared as a potent alternative due to their multiple biological activities. They represent a powerful strategy to prevent the development of spore-forming microorganisms in foods. Unlike thermal methods, they are natural without an adverse impact on food organoleptic and nutritional attributes. AMPs such as nisin and bacteriocins are generally effective in eliminating the vegetative forms of spore-forming bacteria compared to the more resilient spore forms. However, in combination with other non-thermal treatments, such as high pressure, supercritical carbon dioxide, electric pulses, a synergistic effect with AMPs such as nisin exists and has been proven to be effective in the inactivation of microbial spores through the disruption of the spore structure and prevention of spore outgrowth. The control of microbial spores in foods is essential in maintaining food safety and extension of shelf-life. Thus, exploration of the mechanisms of action of AMPs such as nisin is critical for their design and effective application in the food industry. This review harmonises information on the mechanisms of bacteria inactivation from published literature and the utilisation of AMPs in the control of microbial spores in food. It highlights future perspectives in research and application in food processing. 相似文献
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The reversible isomerism of indolinospirobenzopyrans is perhaps among the most studied phenomena in the field of molecular switches. Although they began to gain attention as early as 70 years ago following the seminal work of Hirshberg and Fischer, who were the first to recognize their photochromic behaviours, their implementation as photoacids emerged prominently only in the last decade. In this Review, we contextualize the prerequisites underlying the photo-triggered proton release that occurs in these molecular switches, highlighting the most recent advances in their characterization and application as “metastable-state photoacids” in water. 相似文献
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《中国化学快报》2019,30(12):2259-2262
A simple and clean protocol for the synthesis of various alkyl and (hetero)aryl S-thiocarbamates was established. The usage of in situ generated hydroxide as both an oxygen source and hydrogen source as well as biomass-derived 2-methyltetrahydrofuran as a green reaction medium, the avoidance of phosphorus-containing reductant, and the generation of harmless water and nitrogen as the side-products have given the present method atom-economy and environmental friendliness. 相似文献
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脂质不仅是细胞膜的主要组成部分,还参与一些生命活动如能量存储、信号传导等,在生命体中发挥着重要作用。近年来,越来越多的研究表明脂质的变化与一些重大疾病的发生发展密切相关,脂质组学研究对理解疾病的发生机制及过程具有重要意义。在脂质分析过程中,由于样品基质的干扰或被分析物浓度的限制,通常需要对样品进行前处理,以得到最佳的分析性能。该文综述了脂质组学分析中的样品前处理技术,包括脂质的提取方法(如液液萃取、固相萃取等)和针对不同类脂质的化学衍生化技术在各领域,尤其是生命分析和代谢组学中的应用,并对脂质组学分析中的样品前处理技术的发展进行了展望。 相似文献
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Jan Sebenda 《Macromolecular Symposia》1986,6(1):1-10
The rate of anionic lactam polymerization is greatly affected by variation of the permittivity of lactams with ring size and substitution, as well as by changes of permittivity during polymerization. Therefore, an estimation of reactivities under comparable conditions is possible in solution only. The lack of any solvent permitting anionic lactam polymerization at low temperatures was circumvented by using living polymers soluble in aprotic solvents as carriers. Such polymers are able to remain in solution even after the addition of a few monomer units of a lactam, the polymer of which is insoluble. In this way, relative reactivities of a series of four-membered lactams, as well as that of the five-membered one were established. 相似文献
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《Mendeleev Communications》2021,31(4):558-560
Radiolytic transformations in acetone proceed with the direct participation of its enol tautomer and its derivatives formed as a result of isomerization of excited molecules and ions, as well as chemical reactions catalyzed by acidic products of radiolysis. 相似文献
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The kinetic features of nonisothermal polymerization of acrylamide in aqueous, mixed aqueousdimethyl sulfoxide, and DMSO solutions in the presence of potassium persulfate as initiator and sodium acetate as complexing agent were studied by differential thermal analysis. 相似文献
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Oxidation of olefins occurs effectively in supercritical carbon dioxide as the reaction medium with dioxygen as the primary oxidant and aldehydes as sacrificial co-oxidants. No catalyst is required, but the reaction is promoted by the stainless steel of the reactor walls. Depending on the substrate, vinylic oxidation or epoxidation can be the prevailing pathway. Epoxidation is particularly effective for substrates with internal double bonds and for long-chain terminal olefins. 相似文献
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Conclusions Additives of iodobenzene, para-iodotoluene, and ortho-iodotoluene increase the relative yield of the para isomer in the nitration of toluene, ethylbenzene, and cumene as well as the yield of 4-nitro-o-xylene in the KNO3/CF3CO2H system.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 714–716, March, 1988. 相似文献