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The effect of side chain length of π-conjugated poly(9,9-dialkylfluorene)s has been studied in semi-dilute (10 mg/mL) toluene solutions using small-angle neutron scattering (SANS) and 1H and 2H NMR spectroscopies. Under these conditions, SANS data indicate that poly(9,9-dinonylfluorene) and poly(9,9-dioctylfluorene) are dissolved down to the molecule level and appear as elongated one-dimensional chains (length >20-30 nm). In contrast, the shorter side chain polymers exhibit a self-association so that poly(9,9-diheptylfluorene) forms thin sheet-like (∼1 nm) and poly(9,9-dihexylfluorene) thin (∼1 nm) and thick sheet-like (>6 nm) aggregates. 1H NMR data, together with the density functional theory (DFT) calculations, however, show that this occurs without changes in the conformation of the polymer backbone. 相似文献
3.
Nico Calavita 《Cities》1985,2(2):106-110
In 1284 the Florence Commune started building the last set of walls that were to surround the city until the second half of the 19th century. In response to the strong demographic and economic expansion of the 13th century, the new walls would have to contain a space commensurate with the present and future grandeur of the Commune.1 When completed in 1333, the walls circled the city for 8.5 kilometres and contained 73 towers, 15 doors and an area five times that included in the previous walls. 相似文献
4.
Ribosome display of mammalian receptor domains 总被引:2,自引:0,他引:2
Many mammalian receptor domains, among them a large number of potential therapeutic target proteins, are highly aggregation-prone upon heterologous expression in bacteria. This severely limits functional studies of such receptor domains and also their engineering towards improved properties. One of these proteins is the Nogoreceptor, which plays a central role in mediating the inhibition of axon growth and functional recovery after injury of the adult mammalian central nervous system. We show here that the ligand binding domain of the Nogoreceptor folds to an active conformation in ternary ribosomal complexes, as formed in ribosome display. In these complexes the receptor is still connected, via a C-terminal tether, to the peptidyl tRNA in the ribosome and the mRNA also stays connected. The ribosome prevents aggregation of the protein, which aggregates as soon as the release from the ribosome is triggered. In contrast, no active receptor was observed in phage display, where aggregation appears to prevent incorporation of the protein into the phage coat. This strategy sets the stage for rapidly studying defined mutations of such aggregation-prone receptors in vitro and to improve their properties by in vitro evolution using the ribosome display technology. 相似文献
5.
Nico Pietroni Davide Tonelli Enrico Puppo Maurizio Froli Roberto Scopigno Paolo Cignoni 《Computer Graphics Forum》2015,34(2):627-641
We introduce a framework for the generation of polygonal gridshell architectural structures, whose topology is designed in order to excel in static performances. We start from the analysis of stress on the input surface and we use the resulting tensor field to induce an anisotropic nonEuclidean metric over it. This metric is derived by studying the relation between the stress tensor over a continuous shell and the optimal shape of polygons in a corresponding gridshell. Polygonal meshes with uniform density and isotropic cells under this metric exhibit variable density and anisotropy in Euclidean space, thus achieving a better distribution of the strain energy over their elements. Meshes are further optimized taking into account symmetry and regularity of cells to improve aesthetics. We experiment with quad meshes and hexdominant meshes, demonstrating that our gridshells achieve better static performances than stateoftheart gridshells. 相似文献
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Bioinspired Synthesis of CaCO3 Superstructures through a Novel Hydrogel Composite Membranes Mineralization Platform: A Comprehensive View 下载免费PDF全文
8.
Filipe Rocha Luís Mateus Urszula Skwara Maíra Aguiar Nico Stollenwerk 《国际计算机数学杂志》2016,93(8):1405-1422
Dengue fever dynamics show seasonality, with the disease transmission being higher during the warmer seasons. In this paper, we analyse seasonally forced epidemic models with and without vector dynamics. We assume small seasonal effects and obtain approximations for the real response of each state variable and also for the corresponding amplitude and phase via decomposition of the sinusoidal forcing into imaginary exponential functions. The analysis begins with the simplest susceptible-infected-susceptible (SIS) model, followed by the simplest model with vector dynamics, susceptible-infected-susceptible for hosts and uninfected-vector (SISUV). Finally, we compare the more complex susceptible-infected-recovered (SIR) and susceptible-infected-recovered for hosts and uninfected-vector (SIRUV) models and conclude that the models give basically the same information when we replace, in the SIR model, the human infectivity by a function of both human and mosquito infectivities. 相似文献
9.
Reviews the book Protecting children from domestic violence: Strategies for community intervention, edited by Peter J. Jaffe, Linda L. Baker, and Alison J. Cunningham (see record 2005-04430-000). The book emerged from the International Conference on Children Exposed to Domestic Violence that was held in London, Ontario in 2001. It begins with an excellent chapter by Jeffrey Edleson synthesizing the literature on the impact of exposure to domestic violence on children. Edleson's chapter is followed by two papers examining emerging assessments and treatment programs. The second section of the book addresses current thinking about individual and group intervention approaches. The third section of the book examines broader system level responses, including public awareness and school-based campaigns, as well as responses by the courts and police. This is a well-organized collection of papers that provides a good overview of the state of knowledge and innovative practice in an emerging field of practice. Protecting Children from Domestic Violence provides practitioners, policy makers, and researchers with an excellent overview of current knowledge and practices in working with children exposed to domestic violence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
Sabrina Valente Carmen Ciavarella Gloria Astolfi Elisa Bergantin Nico Curti Marina Buzzi Luigi Fontana Piera Versura 《International journal of molecular sciences》2022,23(18)
Blood-based preparations are used in clinical practice for the treatment of several eye disorders. The aim of this study is to analyze the effect of freeze-drying blood-based preparations on the levels of growth factors and wound healing behaviors in an in vitro model. Platelet-rich plasma (PRP) and serum (S) preparations from the same Cord Blood (CB) sample, prepared in both fresh frozen (FF) and freeze-dried (FD) forms (and then reconstituted), were analyzed for EGF and BDNF content (ELISA Quantikine kit). The human MIO-M1 glial cell line (Moorfield/Institute of Ophthalmology, London, UK) was incubated with FF and FD products and evaluated for cell migration with scratch-induced wounding (IncuCyte S3 Essen BioScience), proliferation with cyclin A2 and D1 gene expression, and activation with vimentin and GFAP gene expression. The FF and FD forms showed similar concentrations of EGF and BDNF in both the S and PRP preparations. The wound healing assay showed no significant difference between the FF and FD forms for both S and PRP. Additionally, cell migration, proliferation, and activation did not appear to change in the FD forms compared to the FF ones. Our study showed that reconstituted FD products maintained the growth factor concentrations and biological properties of FF products and could be used as a functional treatment option. 相似文献