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排序方式: 共有387条查询结果,搜索用时 17 毫秒
1.
Marcel Schmidt Dr. Yen-Hua Huang Dr. Eduardo F. Texeira de Oliveira Dr. Ana Toplak Dr. Hein J. Wijma Prof. Dr. Dick B. Janssen Prof. Dr. Jan H. van Maarseveen Prof. Dr. David J. Craik Dr. Timo Nuijens 《Chembiochem : a European journal of chemical biology》2019,20(12):1524-1529
Disulfide-rich macrocyclic peptides—cyclotides, for example—represent a promising class of molecules with potential therapeutic use. Despite their potential their efficient synthesis at large scale still represents a major challenge. Here we report new chemoenzymatic strategies using peptide ligase variants—inter alia, omniligase-1—for the efficient and scalable one-pot cyclization and folding of the native cyclotides MCoTI-II, kalata B1 and variants thereof, as well as of the θ-defensin RTD-1. The synthesis of the kB1 variant T20K was successfully demonstrated at multi-gram scale. The existence of several ligation sites for each macrocycle makes this approach highly flexible and facilitates both the larger-scale manufacture and the engineering of bioactive, grafted cyclotide variants, therefore clearly offering a valuable and powerful extension of the existing toolbox of enzymes for peptide head-to-tail cyclization. 相似文献
2.
Norgauer Philipp Grunewald Laura Priester Lena Heilemann Jens Hein Michael Stahl Karsten 《Forschung im Ingenieurwesen》2020,84(2):141-150
Forschung im Ingenieurwesen - Schneckengetriebe finden sich in verschiedenen Anwendungen als Stell- und Leistungsgetriebe. Aufgrund der Realisierbarkeit einer hohen Übersetzung bei kleinem... 相似文献
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In the present study the possibility of using nicotine in house dust as an index of environmental tobacco smoke (ETS) exposure was evaluated in an environmental investigation of 23 children with asthma. A standardized procedure for house dust sampling of nicotine with a filter holder connected to a vacuum cleaner, for a defined time and area was developed (F-nicotine). Also, house dust sampling was carried out from the vacuum cleaner bags of the homes (VC-nicotine). There was a larger variation in VC-nicotine (13-655, median 66 microg/g) compared with F-nicotine (15-393 median 156 microg/g). There were statistically significant associations between an inquiry data based ETS exposure index on the one hand, and urinary cotinine concentrations in children (U-cotinine), F-nicotine and VC-nicotine of their homes, on the other. The strong correlation between U-cotinine and F-nicotine (rs = 0.93; P < 0.0001) indicates that the new standardized house dust sampling method should be useful in ETS exposure assessment. However, further validation by a larger sample size with repeated measurements in the same homes is needed. 相似文献
5.
Infrastructure, ecology and art 总被引:3,自引:0,他引:3
In keeping with the ‘industrial ecology’ metaphor, roads and railways should be regarded as forming an ecosystem with their surroundings, just like industrial systems (factory premises, manufacturing industries) that have had to start functioning as ecosystems in which the flow of energy, water, raw materials and waste products has been made to recycle as far as possible. In this type of system approach, the flow of material, transport, emissions and energy and the habitats of plants and animals are geographically, systematically and functionally integrated, especially when they are based on a greater degree of interweaving between man and nature than is currently the case. In short, a new way of looking at the meaning of ecology in relation to the physical infrastructure.In the article, examples are given about the practical implication of linking ecological patterns and processes within the design process of civil engineering object, as well as the possible art’s contribution in forming infrastructural landscapes. 相似文献
6.
People around the world have shaped societies and urban spaces around water for millennia. They have transformed natural water structures and patterns to serve their diverse needs. The ways in which historical decisions affect contemporary water systems and influence future planning of urban systems still need to be fully recognized. This paper explores the multiple roles of water systems in Chang'an during the Western Han Dynasty. Chang’an, one of the ancient names for the city of Xi’an, was a typical capital city of China and East Asia in early ancient times. This study explores everyday practices pertaining to water as well as its role in defense, gardening, politics and culture.Drawing upon three historical theories, this study presents findings that water was embedded in the design of traditional Chinese capitals. The siting and construction of capital cities was first based on the Theory of Choosing the Center (3rd century BCE) and the Theory of Conforming to Nature (5th–3rd century BCE). However, the final maturation of this urban morphology, including the water system, was closely related to the Theory of Symbolizing and Modeling Heaven and Earth (4th–3rd century BCE), in a way that manifested the imperial power's organization and control of space and time.Through close analysis of historical documents, archaeological reports and modern investigations, the paper aims to clarify, analyze and summarize the historical context and evolution, functional and structural characteristics, as well as the economic, political, cultural and military connotations of water systems in Chang'an. It argues that the coordination of urban construction and the water environment was a key foundation for capital city development. It proposes that people shaped urban water supply in many ways, including daily life, waterway transportation, agricultural irrigation, aquaculture promotion, military defense and fire prevention.The water system in Chang'an also provided an important place for royalty and nobility to go fishing, to hunt and to engage in leisure and naval training. The landscape with this water system as the core, including Taiye Lake and Kunming Lake, had also inspired Chinese gardening history, and had a profound impact on future generations. More importantly, the capital's urban morphology design was a miniature of the world recognized by the monarch, as well as the symbolic image of the supreme rulers' political and cultural desire to control and possess Tianxia, which essentially means the whole world. In conclusion, the paper calls for a closer study of water-based design as a foundation for urban planning. 相似文献
7.
Wibke Exner Robert Hein Thorsten Mahrholz Peter Wierach Hans Peter Monner Michael Sinapius 《应用聚合物科学杂志》2019,136(5):47031
This article investigates the potential of aluminum oxide nanoparticles for the reduction of process-induced distortions of carbon fiber reinforced plastics (CFRP). Therefore the matrix properties, which affect the distortions, are experimentally and mechanistically analyzed in detail at various particle contents. The results clearly show an increasing impact of raised particle content on gelation, chemical and thermal shrinkage, on Young's modulus, as well as on Poisson's ratio. These alterations can be successfully transferred to reduce spring-in of L-shaped CFRP brackets, which are manufactured by infusion technology. However, it is found that particle contents higher than 5 wt % are needed to influence these parameters. For further understanding of the parameters controlling spring-in, a numerical sensitivity analysis is performed by the correlation of various matrix parameters and the induced distortions. The results from a structural simulation reveal that changes in thermal and chemical shrinkage as well as in gelation have a major impact on the distortions, but the modes of action of the particles also have to be taken into consideration. These mechanistical insights about nanoparticle impacts might be a valuable approach to lower or overcome distortions in composite materials in the future. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47031. 相似文献
8.
van Stralen Maartje M.; de Vries Hein; Mudde Aart N.; Bolman Catherine; Lechner Lilian 《Canadian Metallurgical Quarterly》2011,30(4):442
Objective: Low-cost (e.g., computer-tailored) interventions with sustained effects are needed to increase and maintain physical activity in older adults. This study examined the long-term efficacy of 2 computer-tailored physical activity interventions for older adults and its psychosocial and environmental mediators. Methods: A clustered randomized controlled trial (N = 1,971) was conducted that included 3 research arms: (a) basic computer-tailored print intervention, targeting psychosocial mediators; (b) environmentally computer-tailored print intervention, targeting psychosocial and environmental mediators; and (c) no-intervention control group. Interventions were developed using the intervention mapping approach and consisted of 3 computer-tailored letters delivered over 4 months. Questionnaires assessed the study outcomes (i.e., total weekly days and total weekly minutes of physical activity) at baseline and 12 months. Potential mediators (i.e., awareness, attitude, self-efficacy, intention, social influence, intrinsic motivation, self-regulation, and perceived environment) were assessed at baseline and at 3 or 6 months. Results: Multilevel regression analyses revealed that both interventions significantly changed total weekly days of physical activity compared with the control group, but only the environmentally computer-tailored print intervention significantly changed weekly minutes of physical activity. Multiple mediation models showed that the effects of both interventions on weekly days of physical activity were mediated by changes in awareness and intention. Conclusions: Computer-tailored interventions were effective in inducing long-term behavioral changes in physical activity behavior of older adults. Awareness and intention were found to be important mediators of changing daily physical activity and should be included in future computer-tailored intervention studies. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
9.
Steven Chiuta Raymond C. Everson Hein W.J.P. Neomagus Percy van der Gryp Dmitri G. Bessarabov 《International Journal of Hydrogen Energy》2013
Hydrogen (H2) fuel obtained via thermo-catalytic ammonia (NH3) decomposition is rapidly attracting considerable interest for portable and distributed power generation systems. Consequently, a variety of reactor technologies are being developed in view of the current lack of infrastructure to generate H2 for proton exchange membrane (PEM) fuel cells. This paper provides an extensive review of the state-of-the-art reactor technology (also referred to as reactor infrastructure) for pure NH3 decomposition. The review strategy is to survey the open literature and present reactor technology developments in a chronological order. The primary objective of this paper is to provide a condensed viewpoint and basis for future advances in reactor technology for generating H2 via NH3 decomposition. Also, this review highlights the prominent issues and prevailing challenges that are yet to be overcome for possible market entry and subsequent commercialization of various reactor technologies. To our knowledge, this work presents for the first time a review of reactor infrastructure for distributed H2 generation via NH3 decomposition. Despite commendable research and development progress, substantial effort is still required if commercialization of NH3 decomposition reactor infrastructure is to be realized. 相似文献
10.
E. Mann I. Hein P. Mester B. Stessl P. Rossmanith M. Wagner M. Dzieciol 《Food Analytical Methods》2013,6(4):991-995
A newly designed TaqMan® probe and an internal amplification control were implemented in a conventional PCR system targeting the major fimbrial subunit encoding gene fimA. This assay has an inclusivity and exclusivity of 100 % (n?=?126). The limit of detection (LOD) and the absolute quantification limit, both determined by advanced Poisson analyses, were three bacterial cell equivalents per quantitative real-time PCR reaction. The fimA assay achieved 100 % accuracy and performed very robustly, producing reproducible, reliable data for quantification of Salmonella spp., even at the LOD. 相似文献