Application of the SUSTAIN Model to a Watershed-Scale Case for Water Quality Management

[[abstract]]Low impact development (LID) is a relatively new concept in land use management that aims to maintain hydrological conditions at a predevelopment level without deteriorating water quality during land development. The United States Environmental Protection Agency (USEPA) developed the System for Urban Stormwater Treatment and Analysis Integration model (SUSTAIN) to evaluate the performance of LID practices at different spatial scales; however, the application of this model has been limited relative to LID modeling. In this study, the SUSTAIN model was applied to a Taiwanese watershed. Model calibration and verification were performed, and different types of LID facilities were evaluated. The model simulation process and the verified model parameters could be used in other cases. Four LID scenarios combining bioretention ponds, grass swales, and pervious pavements were designed based on the land characteristics. For the SUSTAIN model simulation, the results showed that pollution reduction was mainly due to water quantity reduction, infiltration was the dominant mechanism and plant interception had a minor effect on the treatment. The simulation results were used to rank the primary areas for nonpoint source pollution and identify effective LID practices. In addition to the case study, a sensitivity analysis of the model parameters was performed, showing that the soil infiltration rate was the most sensitive parameter affecting the LID performance. The objectives of the study are to confirm the applicability of the SUSTAIN model and to assess the effectiveness of LID practices in the studied watershed.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]電子

Enteral Nutrition in Adult Crohn’s Disease: Toward a Paradigm Shift

Medical and surgical treatments for Crohn’s disease are associated with toxic effects. Medical therapy aims for mucosal healing and is achievable with biologics, immunosuppressive therapy, and specialised enteral nutrition, but not with corticosteroids. Sustained remission remains a therapeutic challenge. Enteral nutrition, containing macro- and micro-nutrients, is nutritionally complete, and is provided in powder or liquid form. Enteral nutrition is a low-risk and minimally invasive therapy. It is well-established and recommended as first line induction therapy in paediatric Crohn’s disease with remission rates of up to 80%. Other than in Japan, enteral nutrition is not routinely used in the adult population among Western countries, mainly due to unpalatable formulations which lead to poor compliance. This study aims to offer a comprehensive review of available enteral nutrition formulations and the literature supporting the use and mechanisms of action of enteral nutrition in adult Crohn’s disease patients, in order to support clinicians in real world decision-making when offering/accepting treatment. The mechanisms of actions of enteral feed, including their impact on the gut microbiome, were explored. Barriers to the use of enteral nutrition, such as compliance and the route of administration, were considered. All available enteral preparations have been comprehensively described as a practical guide for clinical use. Likewise, guidelines are reported and discussed

Bio-inspired mineral growth on porous spherulitic textured poly(L-lactic acid)/bioactive glass composite scaffolds

It has been shown that texture can strongly influence the adhesion, orientation and proliferation of cells onto the surface of biomaterials. Additionally, it is possible to imprint micrometer level textures throughout the scaffolds by melt compounding PLLA/polyethylene oxide (PEO) blend, quenching followed by leaching of PEO in water. The objective of this work is to verify how the texture in 3D porous PLLA/Bioglass®composite scaffolds may influence the precipitation of apatite in vitro. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.Financial support for this work was provided by FCT, through tire POCTI and FEDER programmes, and projects POCTI/FIS/61621/2004 and PTDC/QUI/69263/2006. S. Ghosh thanks FCT for awarding the PhD grant, SFRH/BD/12657/2003. This work was also partially supported by the European Union funded STREP Project HIPPOCRATES(NMP3-CT-2003-505758)

Bioactive sol-gel glasses at the atomic scale:the complementary use of advanced probe and computer modeling methods

Sol-gel-synthesized bioactive glasses may be formed via a hydrolysis condensation reaction, silica being introduced in the form of tetraethyl orthosilicate (TEOS), and calcium is typically added in the form of calcium nitrate. The synthesis reaction proceeds in an aqueous environment; the resultant gel is dried, before stabilization by heat treatment. These materials, being amorphous, are complex at the level of their atomic-scale structure, but their bulk properties may only be properly understood on the basis of that structural insight. Thus, a full understanding of their structure-property relationship may only be achieved through the application of a coherent suite of leading-edge experimental probes, coupled with the cogent use of advanced computer simulation methods. Using as an exemplar a calcia-silica sol-gel glass of the kind developed by Larry Hench, in the memory of whom this paper is dedicated, we illustrate the successful use of high-energy X-ray and neutron scattering (diffraction) methods, magic-angle spinning solid-state NMR, and molecular dynamics simulation as components to a powerful methodology for the study of amorphous materials

Novel rice-shaped bioactive ceramic nanoparticles

A study was conducted to synthesize needle-like or rice-shaped bioactive ceramic (BAC) nanoparticles. These nanoparticles were formulated with an unusually low silicon content and a relatively high phosphorus concentration. This system combined the advantages of hydroxyapatite and bioactive glasses, enhancing its potential applicability in regeneration strategies for mineralized tissues or more conventional medical applications. It was observed that nanoparticles can be mixed with some bridgeable polymers to develop new biomaterials with improved mechanical properties and adequate bioactivity. The study produced new rice-shaped or claviform low-silicon-content bioceramic nanoparticles using an improved sol-gel method, with sizes of about 70nm in diameter and 210nm in length. It was concluded that these bioactive nanoparticles contained small quantity of silicon and showed excellent biomineralization capability.This work was financially supported by the Foundation for Science and Technology (FCT) via a grant for postdoctoral research (SFRH/BPD/25828/2005) and by project PTDC/QUI/69263/2006

In vitro bioactivity of titanium-doped bioglass

Previous studies have suggested that incorporating relatively small quantities of titanium dioxide into bioactive glasses may result in an increase in bioactivity and hydroxyapatite formation. The present work therefore investigated the in vitro bioactivity of a titanium doped bioglass and compared the results with 45S5 bioglass. Apatite formation was evaluated for bioglass and Ti-bioglass in the presence and absence of foetal calf serum. Scanning electron microscopy (SEM) images were used to evaluate the surface development and energy dispersive X-ray measurements provided information on the elemental ratios. X-ray diffraction spectra confirmed the presence of apatite formation. Cell viability was assessed for bone marrow stromal cells under direct and indirect contact conditions and cell adhesion was assessed using SEM

Biomedical applications of natural-based polymers combined with bioactive glass nanoparticles

In recent years, the combination of natural polymers with nanoparticles has permitted the development of sophisticated and efficient bioinspired constructs. In this regard, the incorporation of bioactive glass nanoparticles (BGNPs) confers a bioactive nature to these constructs, which can then induce the formation of a bone-like apatite layer upon immersion in a physiological environment. Moreover, the incorporation of bioactive glass nanoparticles has been found to be beneficial; the constructs proved to be biocompatible, promote cell adhesion and spreading, and regulate osteogenic commitment. This review provides a summary and discussion of the composition, design, and applications of bioinspired nanocomposite constructs based on BGNPs. Examples of nanocomposite systems will be highlighted with relevance to biomedical applications. It is expected that understanding the principles and the stateof-the-art of natural nanocomposites may lead to breakthroughs in many research areas, including tissue engineering and orthopaedic devices. The challenges regarding the future translation of these nanostructured composites into clinical use are also summarized.A´lvaro J. Leite acknowledges the Portuguese Foundation for Science and Technology (FCT) for his doctoral grant (SFRH/BD/73174/2010).info:eu-repo/semantics/publishedVersio