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101.
Snia I. G. Fangaia Pedro M. G. Nicolau Fernando A. D. R. A. Guerra M. Melia Rodrigo Gianluca Utzeri Ana M. T. D. P. V. Cabral Artur J. M. Valente Miguel A. Esteso Ana C. F. Ribeiro 《International journal of molecular sciences》2021,22(24)
Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions. The ternary mutual diffusion coefficients of metal ions (Co and Cr) in the presence of chlorhexidine digluconate, in an artificial saliva media, were measured. Significant coupled diffusion of CoCl2 (and CrCl3) and chlorhexidine digluconate is observed by analysis of the non-zero values of the cross-diffusion coefficients, D12 and D21. The observed interactions between metal ions and chlorhexidine digluconate suggest that the latter might be considered as an advantageous therapeutic agent, once they contribute to the reduction of the concentration of those ions inside the mouth. 相似文献
102.
Orazio A. Attanasi Stefano Berretta Lucia De Crescentini Gianfranco Favi Gianluca Giorgi Fabio Mantellini Simona Nicolini 《Advanced Synthesis \u0026amp; Catalysis》2011,353(4):595-605
The zinc(II) triflate‐catalyzed synthesis of highly functionalized pyrroles is described. The sequence involves the preliminary preparation of α‐aminohydrazones by Michael addition of primary amines to 1,2‐diaza‐1,3‐dienes. The treatment of these intermediates with dialkyl acetylenedicarboxylates produces α‐(N‐enamino)‐hydrazones that are converted into the corresponding pyrroles. The substituents on the carbon in position four of 1,2‐diaza‐1,3‐dienes drive the regioselectivity of the ring closure process. Starting from 4‐aminocarbonyl‐1,2‐diaza‐1,3‐dienes only dialkyl 1‐substituted 5‐aminocarbonyl‐1H‐pyrrole‐2,3‐dicarboxylates are achieved by Lewis acid‐catalyzed ring closure. A screening of several Lewis/Brønsted acid catalysts is performed. Zinc(II) triflate is the most efficient catalyst. Under similar reaction conditions, employing 4‐alkoxycarbonyl‐1,2‐diaza‐1,3‐dienes, only 4‐hydroxy‐1H‐pyrrole‐2,3‐dicarboxylates are synthesized. These latter reactions can be accomplished regioselectively also in one pot. Using 4‐aminocarbonyl‐1,2‐diaza‐1,3‐dienes, diamines and dialkyl acetylenedicarboxylates the sequence provides the corresponding α,ω‐di(N‐pyrrolyl)alkanes. 相似文献
103.
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105.
Laura Dipasquale Giuliana d'Ippolito Carmela Gallo Filomena Monica Vella Agata Gambacorta Gianluca Picariello Angelo Fontana 《International Journal of Hydrogen Energy》2012
Planktic diatoms are the largest primary producers in marine and freshwater habitats. Their dry biomass accumulates up to 50% of lipids and contains water-soluble β-1,3-glucans as major storage products. Because of the world-wide abundance of these photosynthetic protists, β-1,3-glucans may rival cellulose as the polysaccharide with the highest annual production on Earth. Here we show the feasibility of a simple and efficient process leading to bio-hydrogen by dark fermentation of microalgal biomass with the thermophilic bacterium Thermotoga neapolitana. Production of the biogas on minimum medium supplemented only with the extract of the diatom Thalassiosira weissflogii proved that algal biomass per se can serve as substrate for sustaining the biotechnological process with no requirement of any pretreatment and external integration of other nutrients. At the same time, lipids unused for the anaerobic production of the biogas, can be employed for production of bio-diesel, thus considerably increasing the economic potential of these renewable feedstocks. 相似文献
106.
Paolo Menesatti Emiliano Canali Giulio Sperandio Gianluca Burchi Ger Devlin Corrado Costa 《Packaging Technology and Science》2012,25(4):203-215
Logistics is a fundamental component of the post‐harvest processes, especially in the floricultural sector where the products have to be marketed in short times after the cutting because of their fragility. In the previous years, new approaches to efficiently manage the logistical function and to reduce costs and environmental impacts have been consolidated. In this paper, the investments for two different containers for flower transportation, one disposable and one reusable, are compared, considering a specific supply chain located in central Italy. All data were provided by stakeholders. These were divided into four groups: purchasing, administration, logistical and disposal costs. For the reusable containers, a reverse logistical system, to collect the return components, was hypothesised by using the network analysis tool of the geographic information system (GIS). Results show that the use of a reusable system, which assures a production with less waste and less environmental pressures, is also economically advantageous. Reusable containers involve an initial investment but became cheaper from the second year of the investment and also remained convenient, considering all the costs related to the return collection of the items. Reusable system permits a financial advantage of approximately 140 k€ in total and 21 k€ for each year, considering all the nine years of analysis. Logistics is responsible of the great contribution of total cost in both the reusable and the disposable container (88% and 76%), probably because of the high fragmentation in the delivery service to sale points. Reverse logistics represents the 17% of the reusable container total costs. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
107.
Aragón J González R Fuentes G Palin L Croce G Viterbo D 《Journal of materials science. Materials in medicine》2012,23(2):259-270
Coralline calcium-hydroxyapatite and calcium carbonate from Porites Porites coral were added to a polymeric matrix based on polyvinyl acetate (POVIAC?), to obtain a novel bone substitute composite as well as a system for the controlled drug (cephalexin) release. Composite
samples with different compositions were characterized by physical–chemical and mechanical methods. Furthermore, the in vitro
release profile of cephalexin and the kinetic behavior of its release from these composites were analyzed by appropriate mathematical
models. It was shown that there is no chemical interaction between the inorganic filler and the polymer matrix, each conserving
the original properties of the raw materials. The compressive mechanical strength and Young modulus of the composite with
17.5% of POVIAC?, has better mechanical properties than those of cancellous bone. The variation of POVIAC? content can affect the cephalexin release kinetic in the composite. The cephalexin release mechanism from the composites
can be considered as the result of the joint contribution of a prevailing Fickian diffusion and of polymer chain relaxation.
It was also demonstrated that cephalexin is occluded inside the composites and not on their surface. 相似文献
108.
Benedetta Marmiroli Gianluca Grenci Fernando Cacho-Nerin Barbara Sartori Peter Laggner Luca Businaro Heinz Amenitsch 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(3-4):329-333
Recently, we have designed, fabricated and tested a free-jet micromixer for time resolved small angle X-ray scattering (SAXS) studies of nanoparticles formation in the <100 μs time range. The microjet has a diameter of 25 μm and a time of first accessible measurement of 75 μs has been obtained. This result can still be improved. In this communication, we present a method to estimate whether a given chemical or biological reaction can be investigated with the micromixer, and to optimize the beam size for the measurement at the chosen SAXS beamline. Moreover, we describe a system based on stereoscopic imaging which allows the alignment of the jet with the X-ray beam with a precision of 20 μm. The proposed experimental procedures have been successfully employed to observe the formation of calcium carbonate (CaCO3) nanoparticles from the reaction of sodium carbonate (Na2CO3) and calcium chloride (CaCl2). The induction time has been estimated in the order of 200 μs and the determined radius of the particles is about 14 nm. 相似文献
109.
Occurrence of variable levels of health‐promoting fruit compounds in horn‐shaped Italian sweet pepper varieties assessed by a comprehensive approach 下载免费PDF全文
110.
Gianluca Pietra Tiziana Bonifacino Davide Talamonti Giambattista Bonanno Alessandro Sale Lucia Galli Laura Baroncelli 《International journal of molecular sciences》2021,22(17)
Retinitis pigmentosa (RP) is a family of inherited disorders caused by the progressive degeneration of retinal photoreceptors. There is no cure for RP, but recent research advances have provided promising results from many clinical trials. All these therapeutic strategies are focused on preserving existing photoreceptors or substituting light-responsive elements. Vision recovery, however, strongly relies on the anatomical and functional integrity of the visual system beyond photoreceptors. Although the retinal structure and optic pathway are substantially preserved at least in early stages of RP, studies describing the visual cortex status are missing. Using a well-established mouse model of RP, we analyzed the response of visual cortical circuits to the progressive degeneration of photoreceptors. We demonstrated that the visual cortex goes through a transient and previously undescribed alteration in the local excitation/inhibition balance, with a net shift towards increased intracortical inhibition leading to improved filtering and decoding of corrupted visual inputs. These results suggest a compensatory action of the visual cortex that increases the range of residual visual sensitivity in RP. 相似文献