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排序方式: 共有846条查询结果,搜索用时 31 毫秒
101.
Hannah C. Nerl Anuj Pokle Lewys Jones Knut Müller‐Caspary Karel H. W. van den Bos Clive Downing Eoin K. McCarthy Nicolas Gauquelin Quentin M. Ramasse Ivan Lobato Dermot Daly Juan Carlos Idrobo Sandra Van Aert Gustaaf Van Tendeloo Stefano Sanvito Jonathan N. Coleman Clotilde S. Cucinotta Valeria Nicolosi 《Advanced functional materials》2019,29(37)
The fabrication of 2D systems for electronic devices is not straightforward, with top‐down low‐yield methods often employed leading to irregular nanostructures and lower quality devices. Here, a simple and reproducible method to trigger self‐assembly of arrays of high aspect‐ratio chiral copper heterostructures templated by the structural anisotropy in black phosphorus (BP) nanosheets is presented. Using quantitative atomic resolution aberration‐corrected scanning transmission electron microscopy imaging, in situ heating transmission electron microscopy and electron energy‐loss spectroscopy arrays of heterostructures forming at speeds exceeding 100 nm s?1 and displaying long‐range order over micrometers are observed. The controlled instigation of the self‐assembly of the Cu heterostructures embedded in BP is achieved using conventional electron beam lithography combined with site specific placement of Cu nanoparticles. Density functional theory calculations are used to investigate the atomic structure and suggest a metallic nature of the Cu heterostructures grown in BP. The findings of this new hybrid material with unique dimensionality, chirality, and metallic nature and its triggered self‐assembly open new and exciting opportunities for next generation, self‐assembling devices. 相似文献
102.
Murgulov Valeria Schweinle Catherine Daub Michael Hillebrecht Harald Fiederle Michael Dědič Václav Franc Jan 《Journal of Materials Science》2022,57(4):2758-2774
Journal of Materials Science - Single crystals of lead-free halide double perovskite Cs2AgBiBr6 sensor material manifest a remarkable potential for application in radiation detection and imaging.... 相似文献
103.
Joaquim Colás Alan Tapscott Valeria Righi Ayman Moghnieh Josep Blat 《Computer Supported Cooperative Work (CSCW)》2017,26(4-6):627-662
In the last decades, advances in interactive information technologies have facilitated collaborative fiction writing, which has become widespread and large-scale. This paper proposes a framework to analyze collaborative storytelling systems, made of a set of parameters divided into six conceptual areas. Four of them relate to the systems and two (process and output) to the results of the collaboration. Through this framework we can study more precisely these different factors of the systems, their interplay, and how they impact the creators’ performance. We also present a controlled extended-duration field study on collaborative storytelling, and we use this framework to comparatively analyze these observations and other relevant experiences in the field of co-creation of shared narrative spaces. As a result, we propose a human-information interaction model for collaborative narrative systems, intended to better support co-creation and address the barriers of this kind of systems turning them into new opportunities for collaboration. 相似文献
104.
Stabilization of the Reductase Domain in the Catalytically Self‐Sufficient Cytochrome P450BM3 by Consensus‐Guided Mutagenesis
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Prof. Dr. Gloria Saab‐Rincón Hanan Alwaseem Dr. Valeria Guzmán‐Luna Leticia Olvera Prof. Dr. Rudi Fasan 《Chembiochem : a European journal of chemical biology》2018,19(6):622-632
The multidomain, catalytically self‐sufficient cytochrome P450 BM‐3 from Bacillus megaterium (P450BM3) constitutes a versatile enzyme for the oxyfunctionalization of organic molecules and natural products. However, the limited stability of the diflavin reductase domain limits the utility of this enzyme for synthetic applications. In this work, a consensus‐guided mutagenesis approach was applied to enhance the thermal stability of the reductase domain of P450BM3. Upon phylogenetic analysis of a set of distantly related P450s (>38 % identity), a total of 14 amino acid substitutions were identified and evaluated in terms of their stabilizing effects relative to the wild‐type reductase domain. Recombination of the six most stabilizing mutations generated two thermostable variants featuring up to tenfold longer half‐lives at 50 °C and increased catalytic performance at elevated temperatures. Further characterization of the engineered P450BM3 variants indicated that the introduced mutations increased the thermal stability of the FAD‐binding domain and that the optimal temperature (Topt) of the enzyme had shifted from 25 to 40 °C. This work demonstrates the effectiveness of consensus mutagenesis for enhancing the stability of the reductase component of a multidomain P450. The stabilized P450BM3 variants developed here could potentially provide more robust scaffolds for the engineering of oxidation biocatalysts. 相似文献
105.
Valeria Di Sarli Gianluca Landi Luciana Lisi Almerinda Di Benedetto 《American Institute of Chemical Engineers》2017,63(8):3442-3449
The potential of diesel particulate filters wash‐coated with highly dispersed nano‐metric ceria particles for continuous regeneration has been investigated. To this end, catalytic filters were prepared, soot‐loaded (avoiding the formation of the cake layer), and regenerated—under isothermal conditions—at temperature ranging from 200–600°C. Results have shown that catalytic oxidation of soot starts from 300°C and, at all temperatures, the selectivity to CO2 is higher than 99%. 475°C is the minimum temperature at which the filter is regenerated via catalytic path. At this temperature, the catalytic filter maintains substantially the same performance over repeated cycles of soot loading and regeneration, indicating that the thermal stability of ceria is preserved. This has been further confirmed by comparison between the outcomes obtained from characterization (X‐ray powder diffraction, N2 adsorption at 77 K, Hg intrusion porosimetry, and scanning electron microscope/energy dispersive X‐ray analysis) of fresh filter and filter subjected to repeated regeneration tests. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3442–3449, 2017 相似文献
106.
Valeria Lingua 《Planning Perspectives》2018,33(4):591-614
ABSTRACTThis paper proposes approaching the emergence and evolution of the Europeanization of national planning using conceptual frameworks from historical institutionalism in order to shed light on the mechanisms and trajectories of domestic change arising from the influence of EU strategic planning. It seeks in particular to examine Europeanization in terms of the extent to which EU spatial planning has become a driving force for institutional changes in very different national planning systems. Returning to the changes that occurred in the Italian and English planning systems in the last two decades, the author provides insight into the attempts to insert and transpose EU spatial planning concepts and instruments into domestic systems, dealing with path dependency and European influence. By reading these processes from a historical institutionalist perspective, the paper aims to enhance understanding of the relative influence of European spatial planning on national planning systems, identifying mechanisms and trajectories of domestic change in different planning systems. Key findings concern the diverse modes and degree of institutionalization of EU strategic spatial planning, examining tendencies to replace the status quo through displacements in England and to progress through a path-dependent trajectory in Italy. 相似文献
107.
Tomei G Ciarrocca M Fiore P Rosati MV Pimpinella B Anzani MF Giubilati R Cangemi C Tomao E Tomei F 《The Science of the total environment》2008,392(2-3):198-202
BACKGROUND: The aim of the study is to evaluate if occupational exposure to chemical, physical and psycho-social urban stressor could cause alterations in plasma free testosterone (T) levels and related diseases in female traffic police vs. control group. PATIENTS AND METHODS: The research was carried out on initial sample of 468 female Municipal Police employees (209 traffic police and 259 controls). After excluding the principal confounding factors, traffic police were matched with controls by age, working life, menstrual cycle day, BMI, drinking habit, cigarette smoking habit, liquorice and soy intake in diet, habitual consumption of Italian coffee. There were 96 female traffic police and 96 controls included in the study. RESULTS: T mean levels were significantly higher in female traffic police compared to controls (p=0.000). The distribution of T values in traffic police and in controls was significant (p=0.000). No significant differences were found comparing the percentage in traffic police and controls concerning dystocial, premature and post-term birth. An increase in mental health disorders was found in traffic police compared to controls but the difference was not significant. CONCLUSION: The increase in T plasma levels observed in traffic police vs. controls can be due to a chronic working exposure to low doses of environmental chemical urban stressor. According to our previous researches T could be used as an early biological marker even before the onset of the related disorders. 相似文献
108.
Hernandez Y Nicolosi V Lotya M Blighe FM Sun Z De S McGovern IT Holland B Byrne M Gun'Ko YK Boland JJ Niraj P Duesberg G Krishnamurthy S Goodhue R Hutchison J Scardaci V Ferrari AC Coleman JN 《Nature nanotechnology》2008,3(9):563-568
Fully exploiting the properties of graphene will require a method for the mass production of this remarkable material. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concentrations up to approximately 0.01 mg ml(-1), produced by dispersion and exfoliation of graphite in organic solvents such as N-methyl-pyrrolidone. This is possible because the energy required to exfoliate graphene is balanced by the solvent-graphene interaction for solvents whose surface energies match that of graphene. We confirm the presence of individual graphene sheets by Raman spectroscopy, transmission electron microscopy and electron diffraction. Our method results in a monolayer yield of approximately 1 wt%, which could potentially be improved to 7-12 wt% with further processing. The absence of defects or oxides is confirmed by X-ray photoelectron, infrared and Raman spectroscopies. We are able to produce semi-transparent conducting films and conducting composites. Solution processing of graphene opens up a range of potential large-area applications, from device and sensor fabrication to liquid-phase chemistry. 相似文献
109.
Laura Cannav Serafina Perrone Valeria Viola Lucia Marseglia Gabriella Di Rosa Eloisa Gitto 《International journal of molecular sciences》2021,22(22)
Premature infants are exposed to increased generation of reactive oxygen species, and on the other hand, they have a deficient antioxidant defense system. Oxidative insult is a salient part of lung injury that begins as acute inflammatory injury in respiratory distress disease and then evolves into chronic and structural scarring leading to bronchopulmonary dysplasia. Oxidative stress is also involved in the pathogenesis of pulmonary hypertension in newborns through the modulation of the vascular tone and the response to pulmonary vasodilators, with consequent decrease in the density of the pulmonary vessels and thickening of the pulmonary arteriolar walls. Oxidative stress has been recognized as both a trigger and an endpoint for several events, including inflammation, hypoxia, hyperoxia, drugs, transfusions, and mechanical ventilation, with impairment of pulmonary function and prolonged lung damage. Redoxomics is the most fascinating new measure to address lung damage due to oxidative stress. The new challenge is to use omics data to discover a set of biomarkers useful in diagnosis, prognosis, and formulating optimal and individualized neonatal care. The aim of this review was to examine the most recent evidence on the relationship between oxidative stress and lung diseases in preterm newborns. What is currently known regarding oxidative stress-related lung injury pathogenesis and the available preventive and therapeutic strategies are also discussed. 相似文献
110.