Search results for "metals"
showing 10 items of 2013 documents
Dense drug-eluting biodegradable Fe-Ag nanocomposites
2021
Abstract Biodegradable metals in orthopedics are aimed to eliminate secondary the surgical intervention for implant removal, and thus improve patient compliance, reduce surgery costs and the risk of infections. In addition, biodegradable implants could be loaded with different drugs to prevent the growth of pathogens and the development of bone infections, kill remaining cancer cells after tumor resection or stimulate bone regeneration. However, drugs undergo thermal decomposition under the conditions of conventional metal fabrication processes. In this work, we describe the fabrication of a dense drug-eluting biodegradable Fe-Ag nanocomposite containing 10 vol% of Ag and loaded with the an…
X-ray crystallography-promoted drug design of carbonic anhydrase inhibitors.
2015
1-N-Alkylated-6-sulfamoyl saccharin derivatives were prepared and assayed as carbonic anhydrase inhibitors (CAIs). During X-ray crystallographic experiments an unexpected hydrolysis of the isothiazole ring was evidenced which allowed us to prepare highly potent enzyme inhibitors with selectivity for some isoforms with medical applications.
Frontiers of metal-coordinating drug design
2020
INTRODUCTION: The occurrence of metal ions in biomolecules is required to exert vital cellular functions. Metal-containing biomolecules can be modulated by small-molecule inhibitors targeting their metal-moiety. As well, the discovery of cisplatin ushered the rational discovery of metal-containing-drugs. The use of both drug types exploiting metal–ligand interactions is well established to treat distinct pathologies. Therefore, characterizing and leveraging metal-coordinating drugs is a pivotal, yet challenging, part of medicinal chemistry. AREA COVERED: Atomic-level simulations are increasingly employed to overcome the challenges met by traditional drug-discovery approaches and to compleme…
Atmospheric Lead Deposition into Guarapina Lagoon, Rio de Janeiro State, Brazil
1988
The rate of anthropogenic mobilization of heavy metals is higher than the natural supply to the sedimentary environments. I n rivers, lakes and various other terrestrial areas, the drastic increase of heavy metals has been accredited to human activity (Tyler 1972). Erlenkeuser et al. (1974) suggest that Cd, Pb, Zn and Cu in the upper sediment sequence of sediment cores collected from Kiel Bight in the Baltic Sea, are the result of fossil fuel use in industries. Such assemblages have been identified in North America by Goldberg et al. (1977, 1979) from both coastal regions. Sediment cores taken from the deepest part of lakes and lagoons have been analysed to study the historical development …
Renewable electricity producing technologies and metal depletion: A sensitivity analysis using the EROI
2015
International audience; More and more attention is being paid to renewable technologies because they are seen as a great opportunity to disengage our society from its dependence on fossil fuels. Such flow-based energy resources that rely on solarenergy are supposed to lead us toward a sustainable energy future. However, because of their high capitalintensity, renewable technologies require large amounts of matter, including both common and rare metals.These metals require energy for their production, and more specifically for their extraction. The energy costassociated with metal extraction is linked to mineral ore grade, meaning that as depletion progresses, energycost increases. In additi…
Byproduct production of minor metals: Threat or opportunity for the development of clean technologies? The PV sector as an illustration
2013
Abstract Today, the fight against global warming and the coming hydrocarbon exhaustion involve a drastic increase of clean energies. These technologies resort to many minor metals which are byproduct of major metals. We will take the definition of Hageluken and Mesker (2010, Complex Life Cycles of Precious and Special Metals. In: Edition Thomas E. Graedel, Ester van der Voet (Eds.), Strungmann Forum Report, Linkages of Sustainability, MIT Press) to show precisely what minor metals are: “[they are] metals that have relatively low production or usage, which occur in low ore concentrations, are regarded as rare, or are not traded at major public exchanges”. We will analyze the byproduct status…
Uptake prediction of nine heavy metals by Eichhornia crassipes grown in irrigation canals: A biomonitoring approach
2021
The principal objective of this study is to generate mathematical regression equations that facilitate the estimation of the extent to which Eichhornia crassipes (C. Mart.) Solms, water hyacinth, absorbs heavy metals (HMs) into four plant organs (laminae, petioles, roots, and stolons). This study considers the absorption of nine HMs (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), and the E. crassipes evaluated in this study were located in three irrigation canals in the North Nile Delta in Egypt, with sampling being conducted in both monospecific and homogenous E. crassipes. Samples of both E. crassipes and water were collected on a monthly basis during one growing season. Analysis of the water s…
Electrochemical synthesis of benzoxazoles from anilides - a new approach to employ amidyl radical intermediates.
2017
A novel electrochemical method for the synthesis of benzoxazoles from readily available anilides is reported. Various functionalities are tolerated and good yields can be achieved. By employing common electrode materials and a simple constant current protocol, this method is an attractive new alternative to conventional pathways.
Peculiarities of Phase Formation in Mn-Based Na SuperIonic Conductor (NaSICon) Systems: The Case of Na1+2xMnxTi2–x(PO4)3 (0.0 ≤ x ≤ 1.5)
2021
This project has received funding from the European Regional Development Fund (Project no. 01.2.2-LMT-K-718-02–0005) under grant agreement with the Research Council of Lithuania (LMTLT). We thank the High Performance Computing Center “HPC Saulėtekis” at the Faculty of Physics, Vilnius University, for the use of computational resources.
Simple and scalable electrochemical synthesis of 2,1-benzisoxazoles and quinoline N-oxides.
2019
Cathodic reduction of the nitro moiety and subsequent intramolecular cyclization affords different substituted 2,1-benzisoxazoles and quinoline N-oxides. This methodology allows the synthesis of two different types of heterocycles from common simple starting materials, using electrons as a sole reagent for this transformation. The electrolysis can be conducted in a very simple undivided electrolysis cell under constant current conditions. This permits working on a larger scale compared to other electrochemical methodologies and represents a significant advantage.