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Anderson S. Costa

Bio: Anderson S. Costa is an academic researcher from Universidade Federal de Goiás. The author has contributed to research in topics: Dipole & Magnetic hyperthermia. The author has an hindex of 3, co-authored 3 publications receiving 800 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the influence of particle chain formation on the normalized heating properties, or specific loss power (SLP) of both low-spherical and high-parallelepiped anisotropy ferrite-based magnetic fluids was explored.
Abstract: Nanostructured magnetic systems have many applications, including potential use in cancer therapy deriving from their ability to heat in alternating magnetic fields. In this work we explore the influence of particle chain formation on the normalized heating properties, or specific loss power (SLP) of both low- (spherical) and high- (parallelepiped) anisotropy ferrite-based magnetic fluids. Analysis of ferromagnetic resonance (FMR) data shows that high particle concentrations correlate with increasing chain length producing decreasing SLP. Monte Carlo simulations corroborate the FMR results. We propose a theoretical model describing dipole interactions valid for the linear response regime to explain the observed trends. This model predicts optimum particle sizes for hyperthermia to about 30% smaller than those previously predicted, depending on the nanoparticle parameters and chain size. Also, optimum chain lengths depended on nanoparticle surface-to-surface distance. Our results might have important implications to cancer treatment and could motivate new strategies to optimize magnetic hyperthermia.

513 citations

Journal ArticleDOI
TL;DR: Analysis of ferromagnetic resonance data shows that high particle concentrations correlate with increasing chain length producing decreasing SLP, and a theoretical model describing dipole interactions valid for the linear response regime is proposed, predicting optimum particle sizes for hyperthermia to about 30% smaller than those previously predicted, depending on the nanoparticle parameters and chain size.
Abstract: Nanostructured magnetic systems have many applications, including potential use in cancer therapy deriving from their ability to heat in alternating magnetic fields. In this work we explore the influence of particle chain formation on the normalized heating properties, or specific loss power (SLP) of both low- (spherical) and high- (parallelepiped) anisotropy ferrite-based magnetic fluids. Analysis of ferromagnetic resonance (FMR) data shows that high particle concentrations correlate with increasing chain length producing decreasing SLP. Monte Carlo simulations corroborate the FMR results. We propose a theoretical model describing dipole interactions valid for the linear response regime to explain the observed trends. This model predicts optimum particle sizes for hyperthermia to about 30% smaller than those previously predicted, depending on the nanoparticle parameters and chain size. Also, optimum chain lengths depended on nanoparticle surface-to-surface distance. Our results might have important implications to cancer treatment and could motivate new strategies to optimize magnetic hyperthermia.

323 citations

Journal ArticleDOI
TL;DR: A new approach is developed and implemented for the study of magnetoliposomes using Monte Carlo simulations based on interaction among nanoparticles considering magnetic dipolar, van der Waals, ionic-steric, and Zeeman interaction potentials that suggest that confinement plays an important role in aggregate formation.
Abstract: In this work we have developed and implement a new approach for the study of magnetoliposomes using Monte Carlo simulations. Our model is based on interaction among nanoparticles considering magnetic dipolar, van der Waals, ionic-steric, and Zeeman interaction potentials. The ionic interaction between nanoparticles and the lipid bilayer is represented by an ionic repulsion electrical surface potential that depends on the nanoparticle-lipid bilayer distance and the concentration of ions in the solution. A direct comparison among transmission electron microscopy, vibrating sample magnetometer, dynamic light scattering, nanoparticle tracking analysis, and experimentally derived static magnetic birefringence and simulation data allow us to validate our implementation. Our simulations suggest that confinement plays an important role in aggregate formation.

9 citations


Cited by
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Journal ArticleDOI
TL;DR: A broad overview of magnetic hyperthermia addressing new perspectives and the progress on relevant features such as the ad hoc preparation of magnetic nanoparticles, physical modeling of magnetic heating, methods to determine the heat dissipation power of magnetic colloids including the development of experimental apparatus and the influence of biological matrices on the heating efficiency is presented in this article.
Abstract: Nowadays, magnetic hyperthermia constitutes a complementary approach to cancer treatment. The use of magnetic particles as heating mediators, proposed in the 1950s, provides a novel strategy for improving tumor treatment and, consequently, patient's quality of life. This review reports a broad overview about several aspects of magnetic hyperthermia addressing new perspectives and the progress on relevant features such as the ad hoc preparation of magnetic nanoparticles, physical modeling of magnetic heating, methods to determine the heat dissipation power of magnetic colloids including the development of experimental apparatus and the influence of biological matrices on the heating efficiency.

545 citations

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TL;DR: A new kind of digital divide is created in the use of data-based knowledge to inform intelligent decision-making in developing countries by long-standing structural shortages in the areas of infrastructure, economic resources and institutions.
Abstract: Big Data for Development: A Review of Promises and Challenges Martin Hilbert, University of California, Davis; hilbert@ucdavis.edu Author’s version Hilbert, M. (2016). Big Data for Development: A Review of Promises and Challenges. Development Policy Review, 34(1), 135–174. http://doi.org/10.1111/dpr.12142 Abstract The article uses a conceptual framework to review empirical evidence and some 180 articles related to the opportunities and threats of Big Data Analytics for international development. The advent of Big Data delivers the cost-effective prospect to improve decision-making in critical development areas such as health care, economic productivity, and security. At the same time, all the well-known caveats of the Big Data debate, such as privacy concerns and human resource scarcity, are aggravated in developing countries by long-standing structural shortages in the areas of infrastructure, economic resources, and institutions. The result is a new kind of digital divide: a divide in data-based knowledge to inform intelligent decision- making. The article systematically reviews several available policy options to foster the opportunities and minimize the risks. Keywords: Big Data, decision-making, innovation, ICT, digital divide, digital, international development. Acknowledgements: The author thanks International Development Research Centre Canada (IDRC) for commissioning a more extensive study that laid the groundwork for the present article. He is also indebted to Manuel Castells, Nathan Petrovay, Francois Bar, and Peter Monge for food for thought, and to Matthew Smith, Rohan Samarajiva, Sriganesh Lokanathan, and Fernando Perini for helpful comments on draft versions, and thanks the United Nations Economic Commission for Latin America and the Caribbean (UN-CEPAL), where part of the research was undertaken. The views expressed herein are those of the author and do not necessarily reflect the views of the United Nations.

458 citations

Journal ArticleDOI
TL;DR: A baseline for future monitoring is provided and potential sources of microplastics are discussed in terms of how and where to implement preventative measures to reduce the contaminant influx.

445 citations

Journal ArticleDOI
TL;DR: The present work addresses the structure, synthesis, properties, and the incorporation of magnetic NPs in nanocomposites, highlighting the most relevant effects of the synthesis on the magnetic and structural properties of the magnet NPs and how these effects limit their utilization in the biomedical area.
Abstract: V.F.C. and A.F. contributed equally to this work. The authors thank the FCT—Fundacao para a Ciencia e Tecnologia—for financial support under framework of the Strategic Funding UID/FIS/04650/2013, project PTDC/ EEI-SII/5582/2014 and project UID/EEA/04436/2013 by FEDER funds through the COMPETE 2020—Programa Operacional Competitividade e Internacionalizacao (POCI). Funds provided by FCT in the framework of EuroNanoMed 2016 call, Project LungChek ENMed/0049/2016 are also gratefully acknowledged. V.F.C., A.F., C.R., and P.M. also thank the FCT for the grants SFRH/BPD/98109/2013, SFRH/BPD/104204/2014, SFRH/ BPD/90870/2012 and SFRH/BPD/96227/2013, respectively. Finally, the authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry Department under the ELKARTEK program.

403 citations

Journal ArticleDOI
TL;DR: This work discusses some of the physics principles for effective heating of MNPs focusing on the role of surface anisotropy, interface exchange an isotropy and dipolar interactions, and some physical and practical limitations of using MNPs in magnetic hyperthermia.
Abstract: Localized magnetic hyperthermia using magnetic nanoparticles (MNPs) under the application of small magnetic fields is a promising tool for treating small or deep-seated tumors. For this method to be applicable, the amount of MNPs used should be minimized. Hence, it is essential to enhance the power dissipation or heating efficiency of MNPs. Several factors influence the heating efficiency of MNPs, such as the amplitude and frequency of the applied magnetic field and the structural and magnetic properties of MNPs. We discuss some of the physics principles for effective heating of MNPs focusing on the role of surface anisotropy, interface exchange anisotropy and dipolar interactions. Basic magnetic properties of MNPs such as their superparamagnetic behavior, are briefly reviewed. The influence of temperature on anisotropy and magnetization of MNPs is discussed. Recent development in self-regulated hyperthermia is briefly discussed. Some physical and practical limitations of using MNPs in magnetic hyperthermia are also briefly discussed.

349 citations