88,944 research outputs found
Preparation and use of calixarene acetamido derivativesfor selective removal of strontium from aqueous solutions
No full textEffectiveness of a soil mapping geomatic approach to predict the spatial distribution of soil types and their properties
No full textA soil map (1:50,000 scale) was recently produced in Sardinia (Italy) using a cost-effective GIS approach. In this study we aimed to verify, in two pilot areas and by means of statistical analysis, the effectiveness of the adopted methodology in representing and predicting the spatial distribution of soil types and properties. We focused on evaluation of 1) the influence of landforms and parent materials on soil types (WRB Reference Soil Groups) and selected soil properties and 2) the suitability of the adopted methodology for calibrating a model to predict land unit composition in terms of different soil types. Leptosols, Regosols and Cambisols were prevalent on slopes, with Leptosols being more frequent on convex slopes and Regosols and Cambisols on concave slopes. In flat areas, soil types mainly depended on the type and age of parent material, with Regosols and Cambisols prevailing on Holocene deposits and highly developed soils (mainly Luvisols) largely prevailing on Pleistocene deposits. On hard rock, Leptosols were very frequent on terrigenous metamorphic rock and frequent on granite. Besides Leptosols, Regosols occurred more frequently than Cambisols on both parent materials. Landforms strongly influenced soil depth and available water capacity. Soils on plains were deeper than those on slopes, where convex forms had shallower soils than concave forms. A similar trend applied to the available water capacity. The parent material had a significant effect on topsoil properties (thickness, texture, pH and organic carbon content) of soils belonging to the same WRB Reference Soil Group (analysis done on the most relevant WRB Reference Soil Groups, i.e. Leptosols, Regosols and Cambisols). We calibrated and tested stepwise multiple linear regressions (MLR) and general linear models (GLM) to predict the composition of map units in terms of different WRB Reference Soil Groups. The two models gave very similar results, with distinct distribution patterns that were coherent with the relationships observed between soil groups and specific combination of terrain attributes and parent materials. Results showed that both models were more reliable in predicting the absence rather than presence of a given soil type
Recualificaciòn de Los Mercados de Trajano en Roma
No full textTesto relativo al progetto di riqualificazione e allestimento dei Mercati di Traiano realizzato a Roma dall'arch. Clement
PEgylated polyester-based nanoncologicals
No full textSeveral PEGylated polyester-based nanoncologicals have been proposed in the literature, some of them nowadays being under preclinical/clinical trials or marketed. In this review, we describe the main features of PEGylated polyesters and their correspondent nanocarriers. A first part is devoted to intravenously injectable PEGylated nanocarriers, which represent the systems most investigated so far. After describing fundamental design rules dictated by the administration route, PEGylated nanocarriers currently under preclinical/clinical investigation or in the market will be described from a technological point of view and related therapeutic implications discussed. Finally, new perspective of use of PE-Gylated nanocarriers for oral and pulmonary delivery of anticancer drugs will be considered. © 2014 Bentham Science Publishers
IMPIEGO DELLE CICLODESTRINE IN MICROSFERE BIODEGRADABILI PER IL RILASCIO CONTROLLATO DI INSULINA.
No full textControlled drug delivery in tissue engineering
No full textThe concept of tissue and cell guidance is rapidly evolving as more information regarding the effect of the microenvironment on cellular function and tissue morphogenesis become available. These disclosures have lead to a tremendous advancement in the design of a new generation of multifunctional biomaterials able to mimic the molecular regulatory characteristics and the three-dimensional architecture of the native extracellular matrix. Micro- and nano-structured scaffolds able to sequester and deliver in a highly specific manner biomolecular moieties have already been proved to be effective in bone repairing, in guiding functional angiogenesis and in controlling stem cell differentiation. Although these platforms represent a first attempt to mimic the complex temporal and spatial microenvironment presented in vivo, an increased symbiosis of material engineering, drug delivery technology and cell and molecular biology may ultimately lead to biomaterials that encode the necessary signals to guide and control developmental process in tissue- and organ-specific differentiation and morphogenesis. © 2007 Elsevier B.V. All rights reserved
KINETICS AND MECHANISM OF IMAZOSULFURON HYDROLYSIS
No full textKnowledge of the kinetics and pathways of hydrolytic degradation is crucial to the prediction of the fate and transport mechanism of chemicals. This work first describes the kinetics of the chemical hydrolysis of imazosulfuron, a new sulfonylurea herbicide, and evaluates the results to propose a degradation pathway. The hydrolysis of imazosulfuron has been studied in aqueous buffers both within the pH range 1.9−12.3 at ambient temperature (thermostated at 25 ± 2 °C) and at pH 3.6 within the temperature range of 15−55 °C. The hydrolysis rate of imazosulfuron was characterized by a first-order kinetics, pH- and temperature-dependent, and accelerated by acidic conditions and higher temperatures. The calculated half-lives at pH 4.5 and 5.9 were 36.5 and 578 days, respectively. At pH 6.6, 7.4, 9.2, and 12.3 no significant change in imazosulfuron concentration was observed after 150 days. Half-lives were much lower at pH <4 (= imazosulfuron pKa), at which they ranged from 3.3 to 6.3 days. Moreover, a change in temperature from 15 to 25 °C in acidic conditions (pH 3.6) decreased the half-life of imazosulfuron by a factor of 4.0; in any case, a 3−5-fold increase in the rate of hydrolysis was found for each 10 °C increase in temperature. In acidic conditions the only hydrolysis products were the two molecules resulting from the cleavage of the sulfonylurea bridge
Pulmonary drug delivery: a role for polymeric nanoparticles?
No full textPulmonary drug delivery represents the best way of treating lung diseases, since it allows direct delivery of the drug to the site of action, with few systemic effects. Meanwhile, the lungs may be used as a portal of entry to the body, allowing systemic delivery of drugs via the airway surfaces into the bloodstream. In both cases, the therapeutic effect of the inhaled drug can be optimized by embedding it in appropriately engineered inhalable carriers, which can protect the drug against lung defense mechanisms and promote drug transport across the extracellular and cellular barriers. To this purpose, the attention has been very recently focused on polymeric nanoparticles (NPs). The aim of this review is to offer an overview on the recent advances in NPs for pulmonary drug delivery. After a description of the main challenges encountered in developing novel inhaled products, the design rules to engineer polymeric NPs for inhalation, and in so doing to overcome barriers imposed by the lungs anatomy and physiology, are described. Then, the state-of-art on inhalable biocompatible polymeric NPs based on enzymaticallydegradable natural polymers and biodegradable poly(ester)s is presented, with a special focus on NP-based dry powders for inhalation. Finally, the in vitro/in vivo models useful to address the never-ending toxicological debate related to the use of NPs for inhalation are describe
Core-shell nanocarriers for cancer therapy. Part I: Biologically oriented design rules
No full textIntroduction: The application of nanotechnologies to the cancer field for therapeutic, imaging or diagnostic purposes represents an advanced and very attractive approach to overcome the main limits related to conventional chemotherapy. In particular, core-shell nanocarriers can be engineered to provide adequate features to overcome the main biological barriers encountered by free anti-cancer drugs. Areas covered: This review will try to summarise the design rules-as dictated by biological requirements-to take into account for proper nanocarrier design and to highlight the potential of administration routes other than intravenous. Expert opinion: Although intravenous injection remains the most investigated route of administration for 'nanoncologicals', research interest towards less explored administration routes allowing localised chemotherapy or delivery in close proximity to the tumour site might change the way cancer is treated in the near future. Nevertheless, an experimental set-up more biologically oriented taking into account an in-depth evaluation of stability in complex media, protein interaction, and cell interaction of novel nanoconstructs could allow their successful translation in pre-clinical and clinical settings. © 2014 Informa UK, Ltd
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