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81.
82.
This paper introduces a joint planning and management optimization approach for cellular networks to limit energy consumption while guaranteeing QoS and minimizing operators Capex and Opex. The modeling framework shows that an effective energy-efficient operation depends on the planning decisions. Conversely, it also shows that planning with energy management operation in view yields more versatile topologies than more traditional models based only on Capex. Results for LTE networks are provided and show that savings up to 65% in energy expenses are possible with slight increases in capital investments. 相似文献
83.
Gian-Pietro Di Sansebastiano Silvia Fornaciari Fabrizio Barozzi Gabriella Piro Laura Arru 《International journal of molecular sciences》2014,15(3):4565-4582
We investigated the effect of auxin and acetylcholine on the expression of the tomato expansin gene LeEXPA2, a specific expansin gene expressed in elongating tomato hypocotyl segments. Since auxin interferes with clathrin-mediated endocytosis, in order to regulate cellular and developmental responses we produced protoplasts from tomato elongating hypocotyls and followed the endocytotic marker, FM4-64, internalization in response to treatments. Tomato protoplasts were observed during auxin and acetylcholine treatments after transient expression of chimerical markers of volume-control related compartments such as vacuoles. Here we describe the contribution of auxin and acetylcholine to LeEXPA2 expression regulation and we support the hypothesis that a possible subcellular target of acetylcholine signal is the vesicular transport, shedding some light on the characterization of this small molecule as local mediator in the plant physiological response. 相似文献
84.
Francesca Palombo C. Peter Winlove Ryan S. Edginton Ellen Green Nick Stone Silvia Caponi Marco Madami Daniele Fioretto 《Journal of the Royal Society Interface》2014,11(101)
Brillouin light scattering (BLS) spectroscopy is a technique that is able to detect thermally excited phonons within a material. The speed of propagation of these phonons can be determined from the magnitude of the Brillouin frequency shift between incident and scattered light, thereby providing a measure of the mechanical properties of the material in the gigahertz range. The mechanical properties of the extracellular matrices of biological tissues and their constituent biopolymers are important for normal tissue function and disturbances in these properties are widely implicated in disease. BLS offers the prospect of measuring mechanical properties on a microscopic scale in living tissues, thereby providing insights into structure–function relationships under normal and pathological conditions. In this study, we investigated BLS in collagen and elastin—the fibrous proteins of the extracellular matrix (ECM). Measurements were made on type I collagen in rat tail tendon, type II collagen in articular cartilage and nuchal ligament elastin. The dependence of the BLS spectrum on fibre orientation was investigated in a backscattering geometry using a reflective substrate. Two peaks, a bulk mode arising from phonon propagation along a quasi-radial direction to the fibre axis and a mode parallel to the surface, depending on sample orientation relative to the fibre axis, could be distinguished. The latter peak was fitted to a model of wave propagation through a hexagonally symmetric elastic solid, and the five components of the elasticity tensor were combined to give axial and transverse Young''s, shear and bulk moduli of the fibres. These were 10.2, 8.3, 3.2 and 10.9 GPa, and 6.1, 5.3, 1.9 and 8 GPa for dehydrated type I collagen and elastin, respectively. The former values are close to those previously reported. A microfocused BLS approach was also applied providing selection of single fibres. The moduli of collagen and elastin are much higher than those measured at lower frequency using macroscopic strains, and the difference between them is much less. We therefore believe, like previous investigators, that molecular-scale viscoelastic effects are responsible for the frequency dependence of the fibre biomechanics. Combining BLS with larger-scale mechanical testing methods therefore should, in the future, provide a means of following the evolution of mechanical properties in the formation of the complex structures found in the ECM. 相似文献
85.
Silvia Curteanu Ciprian-George Piuleac Jose J. Linares Pablo Cañizares Manuel A. Rodrigo Justo Lobato 《International Journal of Hydrogen Energy》2014
A multi-objective optimization strategy, based on stacked neural network–genetic algorithm (SNN–GA) hybrid approach, was applied to study the C/PBI content on a high temperature PEMFC performance. The operating conditions of PEMFC were correlated with power density and electrochemical active surface area for electrodes. The structure of the stack was determined in an optimal form related to the contribution of individual neural networks, after applying an interpolation based procedure. Multi-objective optimization using SNN as model and GA as solving procedure provides optimal working conditions which lead to a high PEMFC performance. Simulation results were in agreement with experimental data, both for model validation and system optimization (the C/PBI content in the range of 17–21%). 相似文献
86.
Daniele Passeri Ugo Sassi Andrea Bettucci Emanuela Tamburri Francesco Toschi Silvia Orlanducci Maria Letizia Terranova Marco Rossi 《Advanced functional materials》2012,22(14):2956-2963
The thermoacoustic effect of isolated single‐wall carbon nanotubes aligned between electrodes is experimentally observed for the first time by imaging the emitted acoustic wave using an atomic force microscopy‐based technique specifically developed for the task. The capability of such a technique for single‐point thermoacoustic measurements is first verified on carbon nanotubes layers with two electrodes for injecting alternate electric current. The technique is then demonstrated to allow the acquisition, simultaneously with the topography, of images reflecting the pressure of the acoustic wave at fixed distance from the sample. Such a capability is used to collect images reflecting the amplitude of acoustic waves generated by isolated nanotubes and nanotube bundles by the thermoacoustic effect. 相似文献
87.
Polymeric micelles can be designed and synthesized to bear polymeric blocks with different hydrophilicities; this triggers their self‐assembly into micellar aggregates similar to those generated with traditional surfactants. The basic structure consists of a hydrophobic core, capable of containing guest substances, and a hydrophilic shell, which stabilizes the payload and protects it from external degradation or prevents its quick elimination from the body. The accumulation of block copolymer micelles (BCMs) in a target cell or tissue can be accomplished by two main mechanisms, passive and active targeting; this allows the payload release at the site of action when desired. Hence, in this general overview, we pay special attention to newly developed single‐stimulus‐ and multi‐stimuli‐responsive delivery systems capable of disassembling and reassembling (in some cases) as a response to changes in their physicochemical properties. Also, special interest is also devoted to multifunctional BCMs incorporating multiple therapeutic agents and/or multiple imaging contrast agents, which can be considered the new generation (third generation) of drug‐delivery systems, that is, nanotheranostic platforms. Finally, a summary of BCM‐based drug‐delivery systems currently under clinical trials is given. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42650. 相似文献
88.
This article explores the relationships between changes in the conception of urban peripheries and changes in urban renewal policies, mainly focusing on policy debates and theoretical discourses developed within Italy. The aim is to test the usefulness of a non‐conventional approach to urban peripheries, both from a theoretical and practical point of view. According to this approach, urban peripheries can be thought of as plural and complex places, which are considered to be a fundamental part of the city and as the builders of urban identity. The article initially explores the changes in describing and interpreting urban peripheries, showing how they must be related to actual changes in urban settlement dynamics, as well as to changes in the theoretical frameworks used to understand the phenomenon of the Italian ‘urban periphery’. The article then shows how changes in interpretation have redefined the objectives and methods of policy interventions in the Italian context. Finally, certain critical issues will be discussed, in particular the origins of urban renewal policies and their recent evolution; the redefinition of the local authority role, and the relationships between institutional and social projects and activities. In this view, institutional projects are considered to be the formal projects carried out by public actors, for example municipalities, in order to manage the change in urban peripheries while social projects are understood as the informal practices of inhabitants of peripheries that change their living neighbourhoods. 相似文献
89.
Vincenzo Contaldi Luigi Imperato Silvia Orsi Ernesto Di Maio Paolo Antonio Netti Salvatore Iannace 《应用聚合物科学杂志》2016,133(48)
In this article, we reports the effects of the processing conditions on the morphological and hollow attributes of polystyrene micrometric hollow particles produced by the use of a recently developed technique based on the gas foaming of spherical, dense particles. By modulating the foaming temperature and saturation pressure, we produced hollow particles with different attributes in terms of hollow dimensions, eccentricity, and open–close features. The results from these small systems were compared, and we found agreement with what is typically observed in bulk polymeric foaming, for example, an increase in the foaming efficiency with saturation pressure and the nonmonotonic effect of temperature. Furthermore, we observed an increase in the hollow number when using nucleating agents with respect to the neat polymer and when using nitrogen with respect to carbon dioxide as the blowing agent. The effects of particle manipulation before foaming to achieve hollow elongated or distorted particles are also reported. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44236. 相似文献
90.
Activity of Fluorine‐Containing Analogues of WC‐9 and Structurally Related Analogues against Two Intracellular Parasites: Trypanosoma cruzi and Toxoplasma gondii
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María N. Chao Catherine Li Melissa Storey Dr. Bruno N. Falcone Dr. Sergio H. Szajnman Prof. Dr. Sergio M. Bonesi Prof. Dr. Roberto Docampo Prof. Dr. Silvia N. J. Moreno Prof. Dr. Juan B. Rodriguez 《ChemMedChem》2016,11(24):2690-2702
Two obligate intracellular parasites, Trypanosoma cruzi, the agent of Chagas disease, and Toxoplasma gondii, an agent of toxoplasmosis, upregulate the mevalonate pathway of their host cells upon infection, which suggests that this host pathway could be a potential drug target. In this work, a number of compounds structurally related to WC‐9 (4‐phenoxyphenoxyethyl thiocyanate), a known squalene synthase inhibitor, were designed, synthesized, and evaluated for their effect on T. cruzi and T. gondii growth in tissue culture cells. Two fluorine‐containing derivatives, the 3‐(3‐fluorophenoxy)‐ and 3‐(4‐fluorophenoxy)phenoxyethyl thiocyanates, exhibited half‐maximal effective concentration (EC50) values of 1.6 and 4.9 μm , respectively, against tachyzoites of T. gondii, whereas they showed similar potency to WC‐9 against intracellular T. cruzi (EC50 values of 5.4 and 5.7 μm , respectively). In addition, 2‐[3‐ (phenoxy)phenoxyethylthio]ethyl‐1,1‐bisphosphonate, which is a hybrid inhibitor containing 3‐phenoxyphenoxy and bisphosphonate groups, has activity against T. gondii proliferation at sub‐micromolar levels (EC50=0.7 μm ), which suggests a combined inhibitory effect of the two functional groups. 相似文献