Littérature scientifique sur le sujet « Iron oxide NPs »
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Articles de revues sur le sujet "Iron oxide NPs"
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Huseen, Rania Hasan, Ali A. Taha, Ihab Q. Ali, Oday Mahmmod Abdulhusein et Selma M. H. Al-Jawad. « Biological activity of gum Arabic-coated ferrous oxide nanoparticles ». Modern Physics Letters B 35, no 24 (28 juillet 2021) : 2150411. http://dx.doi.org/10.1142/s021798492150411x.
Texte intégralRésumé :
In this study, iron oxide nanoparticles (NPs) had been prepared by co-precipitation method. In order to reduce their toxicity and increase stability, prepared iron oxide was coated with gum Arabic. Gum Arabic is preferred over synthetic materials due to their non-toxicity, low cost and availability. Characterization of coated and non-coated iron oxide NPs had been performed by spectrophotometer, Fourier transfer infra-red spectrophotometer (FTIR), Zeta potential, X-ray diffraction (XRD) and field emission scanning electron microscopic (FE-SEM). The fabricated nanoparticles appeared purity and crystalline nature by XRD, with diameter average of 27.01 nm and 55.12 nm for iron oxide NPs and iron oxide NPs coated with gum Arabic, respectively. On the other hand, four biological activities of coated and non-coated iron oxide had been investigated. High removal of methylene blue pollutant dye (46%) was observed with iron oxide NPs, while removal percentage was 22.6 performed by iron oxide NPs coated with gum Arabic within 72 h. Iron oxide NPs revealed high inhibition zones of 27.5 nm and 30 mm, at 1000 [Formula: see text]g/ml, against S. aureus and E. coli, respectively, while coated iron oxide NPs with gum Arabic revealed low antibacterial activity against both examined bacteria even when used at 1000 [Formula: see text]g/ml. The hemolytic activity of prepared NPs had been determined. The hemolytic percentage was increased whenever concentrations of nanoparticles increased. Lower hemolytic percentages were 69.76 and 50.98 for iron oxide NPs and iron oxide NPs coated with gum Arabic were observed at a concentration of 250 [Formula: see text]g/ml. Finally, cytotoxic activity was estimated against MCF-7 cell line and normal cell line WRL68 by MTT assay. A decrease in MCF-7 viability to 65.1% was observed when 400 [Formula: see text]g/ml of iron oxide NPs was used, while WRL68 viability was 75.03%. Iron oxide NPs coated with gum Arabic revealed significant reduction in MCF-7 and WRL68 viability to 69.90% and 80.05%, respectively, when 400 [Formula: see text]g/ml of nanoparticles was applied.
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Batool, Sadaf, et Zakir Hussain. « Diospyros lotus-mediated Synthesis of Iron Oxide Nanoparticles and Their Application as a Catalyst in Fenton Reaction ». Current Nanoscience 16, no 1 (22 janvier 2020) : 91–100. http://dx.doi.org/10.2174/1573413715666191023103729.
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Background: : Iron Oxide nanoparticles have enormous applications in environmental remediation and catalysis. The synthesis of such nanoparticles through a green approach provides a significant advantage due to the non-toxic nature of the ingredients involved. Method: : In the present work, Diospyros lotus fruit extract was used for the synthesis of iron oxide nanoparticles (NPs). The plant biomolecules were extracted employing two different solvents, i.e. water and methanol. The effect of both the extracts on the reduction of metal salt as well as on the shape and size of the produced NPs was investigated. Results:: UV-Visible spectroscopy confirmed the synthesis of iron oxide NPs, Fourier Transform Infrared (FTIR) spectrum depicted the presence of biomolecules on the surface of NPs as capping agents, X-ray Diffraction (XRD) diffractogram confirmed the crystalline structure of mixed iron oxide NPs and Scanning Electron Microscopy (SEM) images showed the spherical shape of NPs. The synthesized NPs were exploited to catalyze the degradation of methylene blue dye in the Fenton type catalytic reaction. The degradation reaction was monitored using UV-Visible spectroscopy, which indicated that the percent degradation increased from 15% (without iron oxide NPs) to 91% in the presence of organic extract prepared iron oxide NPs and to 81% in the presence of aqueous extract prepared iron oxide NPs. The effect of the concentration of methylene blue and iron oxide NPs on the degradation process was also investigated. Conclusion: : The results indicated the potential of synthesized nanoparticles to promote catalytic reactions involved in environmental remediation.
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Curcio, Alberto, Aurore Van de Walle, Christine Péchoux, Ali Abou-Hassan et Claire Wilhelm. « In Vivo Assimilation of CuS, Iron Oxide and Iron Oxide@CuS Nanoparticles in Mice : A 6-Month Follow-Up Study ». Pharmaceutics 14, no 1 (13 janvier 2022) : 179. http://dx.doi.org/10.3390/pharmaceutics14010179.
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Nanoparticles (NPs) are at the leading edge of nanomedicine, and determining their biosafety remains a mandatory precondition for biomedical applications. Herein, we explore the bioassimilation of copper sulfide NPs reported as powerful photo-responsive anticancer therapeutic agents. The nanoparticles investigated present a hollow shell morphology, that can be left empty (CuS NPs) or be filled with an iron oxide flower-like core (iron oxide@CuS NPs), and are compared with the iron oxide nanoparticles only (iron oxide NPs). CuS, iron oxide@CuS and iron oxide NPs were injected in 6-week-old mice, at doses coherent with an antitumoral treatment. Cu and Fe were quantified in the liver, spleen, kidneys, and lungs over 6 months, including the control animals, thus providing endogenous Cu and Fe levels in the first months after animal birth. After intravenous NPs administration, 77.0 ± 3.9% of the mass of Cu injected, and 78.6 ± 3.8% of the mass of Fe, were detected in the liver. In the spleen, we found 3.3 ± 0.6% of the injected Cu and 3.8 ± 0.6% for the Fe. No negative impact was observed on organ weight, nor on Cu or Fe homeostasis in the long term. The mass of the two metals returned to the control values within three months, a result that was confirmed by transmission electron microscopy and histology images. This bioassimilation with no negative impact comforts the possible translation of these nanomaterials into clinical practice.
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Sabry, Raad S., Muslim A. Abid et Sarah Q. Hussein. « Effects of Change PH on The Structural and Optical Properties of Iron Oxide Nanoparticles ». Al-Mustansiriyah Journal of Science 32, no 3 (24 juin 2021) : 58. http://dx.doi.org/10.23851/mjs.v32i3.967.
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Iron oxide nanoparticles were made using celery extract by chemical method with change PH. Bio-materials in celery extract synthesized the iron oxide nanoparticles by reducing iron (III) chloride (FeCl3) and then acted as both capping and stabilizing agents. The iron oxide NPs were characterized by XRD, SEM, and UV–vis techniques. The change PH affected the size, shape, and purity of iron oxide NPs. XRD results showed Crystallite size increased from 16.71nm to 21.65nm as pH was increased from 1.6 to 12. SEM images showed that the particle size of (α-Fe2O3) NPs was around 40.06 nm, while increasing PH showed different shapes in the same sample. The particle size became approximately 45.56 and 61.22 nm. UV–vis measurements showed the energy band increased from 3.11eV to 5.11eV. The antimicrobial activity of iron oxide NPs was determined by growth inhibition zones of the negative gram bacteria E. coli, Klebsiella spp, and gram-positive bacteria S. aureus, S. epidermidis, and fungal Candida albicans. The zones for (α-Fe2O3) NPs when PH 1.6 was between (12-13) mm. The zones for (α-Fe2O3) NPs when PH 12 was a little higher between (13-15) mm.
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Suryawanshi, Prashant L., Shirish H. Sonawane, Bharat A. Bhanvase, Muthupandian Ashokkumar, Makarand S. Pimplapure et Parag R. Gogate. « Synthesis of iron oxide nanoparticles in a continuous flow spiral microreactor and Corning® advanced flow™ reactor ». Green Processing and Synthesis 7, no 1 (23 février 2018) : 1–11. http://dx.doi.org/10.1515/gps-2016-0138.
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AbstractIn the present work, synthesis of iron oxide nanoparticles (NPs) using continuous flow microreactor (MR) and advanced flow™ reactor (AFR™) has been investigated with evaluation of the efficacy of the two types of MRs. Effect of the different operating parameters on the characteristics of the obtained NPs has also been investigated. The synthesis of iron oxide NPs was based on the co-precipitation and reduction reactions using iron (III) nitrate precursor and sodium hydroxide as reducing agents. The iron oxide NPs were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and X-ray diffraction (XRD) analysis. The mean particle size of the obtained NPs was less than 10 nm at all flow rates (over the range of 20−60 ml/h) in the case of spiral MR, while, in the case of AFR™, the particle size of NPs was below 20 nm with no specific trend observed with the operating flow rates. The XRD and TEM analyses of iron oxide NPs confirmed the crystalline nature and nanometer size range, respectively. Further, magnetic properties of the synthesized iron oxide NPs were studied using electron spin resonance spectroscopy; the resonance absorption peak shows theg-factor values as 2.055 and 2.034 corresponding to the magnetic fields of 319.28 and 322.59 mT for MR and AFR™, respectively.
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Snoderly, Hunter T., Kasey A. Freshwater, Celia Martinez de la Torre, Dhruvi M. Panchal, Jenna N. Vito et Margaret F. Bennewitz. « PEGylation of Metal Oxide Nanoparticles Modulates Neutrophil Extracellular Trap Formation ». Biosensors 12, no 2 (16 février 2022) : 123. http://dx.doi.org/10.3390/bios12020123.
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Novel metal oxide nanoparticle (NP) contrast agents may offer safety and functionality advantages over conventional gadolinium-based contrast agents (GBCAs) for cancer diagnosis by magnetic resonance imaging. However, little is known about the behavior of metal oxide NPs, or of their effect, upon coming into contact with the innate immune system. As neutrophils are the body’s first line of defense, we sought to understand how manganese oxide and iron oxide NPs impact leukocyte functionality. Specifically, we evaluated whether contrast agents caused neutrophils to release web-like fibers of DNA known as neutrophil extracellular traps (NETs), which are known to enhance metastasis and thrombosis in cancer patients. Murine neutrophils were treated with GBCA, bare manganese oxide or iron oxide NPs, or poly(lactic-co-glycolic acid) (PLGA)-coated metal oxide NPs with different incorporated levels of poly(ethylene glycol) (PEG). Manganese oxide NPs elicited the highest NETosis rates and had enhanced neutrophil uptake properties compared to iron oxide NPs. Interestingly, NPs with low levels of PEGylation produced more NETs than those with higher PEGylation. Despite generating a low rate of NETosis, GBCA altered neutrophil cytokine expression more than NP treatments. This study is the first to investigate whether manganese oxide NPs and GBCAs modulate NETosis and reveals that contrast agents may have unintended off-target effects which warrant further investigation.
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Hafeez, M., R. Shaheen, S. Ali, H. A. Shakir, M. Irfan, T. A. Mughal, A. Hassan, M. A. Khan et S. Mumtaz. « Populus ciliata conjugated of iron oxide nanoparticles and their potential antibacterial activities against human bacterial pathogens ». Digest Journal of Nanomaterials and Biostructures 16, no 3 (juillet 2021) : 899–906. http://dx.doi.org/10.15251/djnb.2021.163.899.
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Green synthesis is gaining huge significance because of its environmentally harmonious nature and low cost. This is an important technique to synthesize metal oxide nanoparticles. In the current study, iron oxide nanoparticles (Fe2O3-NPs) were formulated by using Populus ciliata leaf extract and ferrous sulphate (FeSO4.7H2O). These NPs were analyzed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Spectroscopy (FT-IR), and Energy Dispersive X-ray (EDX). The synthesized NPs were used against Gram positive and negative bacteria to find their bactericidal potential. These NPs were found active against Klebsiella pneumonia, Escherichia coli, Bacillus (B) lichenifermis and B. subtilis. B. licheniformis showed the highest antibacterial activity (zone of inhibition) up to 29.1±0.5 mm at 8 mg/mL concentration. This study concludes that Populus ciliata conjugated Iron oxides NPs could be used a potential antibacterial agent.
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Mokhosi, Seipati Rosemary, Wendy Mdlalose, Amos Nhlapo et Moganavelli Singh. « Advances in the Synthesis and Application of Magnetic Ferrite Nanoparticles for Cancer Therapy ». Pharmaceutics 14, no 5 (26 avril 2022) : 937. http://dx.doi.org/10.3390/pharmaceutics14050937.
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Cancer is among the leading causes of mortality globally, with nearly 10 million deaths in 2020. The emergence of nanotechnology has revolutionised treatment strategies in medicine, with rigorous research focusing on designing multi-functional nanoparticles (NPs) that are biocompatible, non-toxic, and target-specific. Iron-oxide-based NPs have been successfully employed in theranostics as imaging agents and drug delivery vehicles for anti-cancer treatment. Substituted iron-oxides (MFe2O4) have emerged as potential nanocarriers due to their unique and attractive properties such as size and magnetic tunability, ease of synthesis, and manipulatable properties. Current research explores their potential use in hyperthermia and as drug delivery vehicles for cancer therapy. Significantly, there are considerations in applying iron-oxide-based NPs for enhanced biocompatibility, biodegradability, colloidal stability, lowered toxicity, and more efficient and targeted delivery. This review covers iron-oxide-based NPs in cancer therapy, focusing on recent research advances in the use of ferrites. Methods for the synthesis of cubic spinel ferrites and the requirements for their considerations as potential nanocarriers in cancer therapy are discussed. The review highlights surface modifications, where functionalisation with specific biomolecules can deliver better efficiency. Finally, the challenges and solutions for the use of ferrites in cancer therapy are summarised.
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Sutunkova, Marina P. « EXPERIMENTAL STUDIES OF TOXIC EFFECTS’ OF METALLIC NANOPARTICLES AT IRON AND NONFERROUS INDUSTRIES AND RISK ASSESSMENT FOR WORKERS` HEALTH ». Hygiene and sanitation 96, no 12 (27 mars 2019) : 1182–87. http://dx.doi.org/10.18821/0016-9900-2017-96-12-1182-1187.
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The paper summarizes main results of our toxicological “in vivo“ experiments on white rats exposed to either a) a single intratracheal instillation of silver, gold, iron oxide, copper oxide, nickel oxide, manganese oxide, zinc oxide and lead oxide nanoparticles (NPs) in stable water suspensions without any chemical additives, b) repeated intraperitoneal injections the same NPs, c) low-level long-term inhalation exposure to the iron oxide nano-aerosol. We found these NPs to be much more noxious on both cellular and systemic levels as compared with their one micrometer or even submicron counterparts. The retention and distribution of metal and metal oxide NPs in the body are controlled by both physiological and physicochemical processes, depended on both cytotoxicity and solubility in biological milieus (inherent in different NPs to varying degrees). The relative contributions of these processes to the toxicokinetics are various for different NPs, and specifically for iron oxide particles of an average diameter not exceeding 20 nm, which were studied in the chronic inhalation experiment, the role of the dissolution predominates. Our data were first to testify to the high activity of the macrophagic and neutrophillic pulmonary phagocytosis of NPs deposited in airways. This fact suggests safe levels of exposure to airborne nanoparticles to be possible in principle but should be much lower if compared with established ones for respective micrometric industrial dust.
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Turi, Muhammad Tahir, Ma Wei, Ittehad Hussain et Javid Hussain. « Arsenic (v) Adsorption by Using Synthesized Iron Oxide Nanoparticles (Fe2O3-NPs) and Aluminum Oxide Nanoparticles (Al2O3-NPs) ». Vol 4 Issue 4 4, no 4 (30 octobre 2022) : 1023–41. http://dx.doi.org/10.33411/ijist/2022040408.
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Arsenic, is one of the most harmful elements to humans, health of chronic diseases, and continuously causing a threat to the world. Arsenic is found in combined form in rocks under the earth's surface and when it dissolves, it contaminates groundwater. In the current research study synthesized iron oxide nanoparticles (Fe2O3-NPs) and aluminum oxide nanoparticles (Al2O3-NPs) for the removal of arsenic (As) (˅) from an aqueous medium and characterized the synthesized material by different analytical techniques such as FT-IR spectroscopy and XRD spectroscopy. The results show successful synthesis of Fe2O3-NPs and Al2O3-NPs. Furthermore, the synthesized material was used as an adsorbent for extraction of as (V) from water. The effect of different parameters such as pH, temperature, contact time, and adsorbent dose on the adsorption process was investigated. The adsorption efficiency was determined by Fe2O3-NPs at about 20 mg/g and Al2O3-NPs at 19.5 mg/g. The quantitative removal of as (V) from industrial water required a minimum amount (0.2 g) of Fe2O3-NPs and Al2O3-NPs. various kinetic and isotherms were investigated in the current study. The result showed that the obtained data for Fe2O3-NPs was more fitted to Pseudo second order kinetic and Freundlich equation, while for Al2O3-NPs the data was more fitted to Pseudo second order kinetic and Elovich model equation, which confirms the interaction among as (V) and adsorbents. Thermodynamic parameters were also investigated which shows the process is spontaneous and endothermic. This model was used to estimate the site energy distribution for each adsorbent. Thermodynamic parameters were also investigated which shows the non-spontaneous and endothermic nature of the adsorbent. According to the results of the analysis of the approximate site energy distribution, adding Fe2O3 and Al2O3-NPs to arsenic decreased the area under the frequency distribution curve of the sorption site energies, which in turn decreased the number of sorption sites that were open to arsenic. This might be explained by the hydrophobic interaction between synthesized materials and arsenic being reduced due to the blocking of the Fe2O3 and Al2O3-NPs hydrophobic surface.
Thèses sur le sujet "Iron oxide NPs"
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Kumar, Rajender. « Development and potential applications of nanomaterials for arsenic removal from contaminated groundwater ». Thesis, KTH, Miljögeokemi och ekoteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-96106.
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In this study, a magnetic nanomaterial was used for the binding of anionic arsenic species from contaminated groundwater. Iron oxide (Fe3O4) magnetic nanoparticles (NPs) and the surface modified Fe3O4 NPs with 3-aminopropyl-triethoxysilane (3-APTES), Trisodium citrare (TSC) and Chitosan were synthesized with the co-precipitation method. Structural characterizations showed that the four kinds of NPs had different sizes an average particle range size of 15-20 nm was observed with Transmission Electron Microscopy. X-ray diffraction was used to identify the crystalline structure of synthesized Fe3O4 and surface modified NPs. Molecular structure and functional groups present in synthesized magnetic NPs Fe3O4 were identify with infrared analysis. The synthesized Fe3O4 NPs and surface coated NPs were used for determine the binding capacity of Arsenic ions from the synthetic groundwater. The binding of As(III) increased as the dissolved As(III) concentration increased in the solution. From the experiments it was found chitosan-coated NPs are best than other coated and uncoated NPs for arsenite removal from the solution. It was found that if only As(III) ions were present in the water without other anions and cations the binding capacity of the magnetic NPs is very high. The binding capacity of As ions was decreased with presence of other anions and cations in the groundwater because they interfere with arsenic binding sites which presence on the magnetic NPs.
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Khalid, Muhammad Kamran [Verfasser]. « Processing and characterization of tailor-made superparamagnetic iron oxide nanoparticles (SPIO-NPs) for pharmaceutical applications / Muhammad Kamran Khalid ». Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2019. http://d-nb.info/1219965340/34.
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LETTIERO, BARBARA. « Uptake and intracellular trafficking of nanoparticles for potential medical use ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2011. http://hdl.handle.net/10281/20247.
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My PhD project has been focused on the characterization of the in vitro behavior of engineered Nanoparticles (NPs), especially concerning the first phases of interaction with barriers of different nature present in the body : a model of air-blood barrier , e.g. alveolar epithelial A30 cell line and an immunological barrier represented by the activation of the complement system. In light of these considerations, I have first compared the mechanism of cellular uptake and intracellular distribution of Solid Lipid NPs and Iron Oxide NPs over time. Then, I have studied the likely molecular basis of in vitro complement activation by NPs, as it can be strongly associated to acute pseudoallergic reactions in sensitive individuals within minutes of NPs infusion.
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Monteiro, Ana Paula de Melo. « Influência do método de preparação nas propriedades do óxido de ferro suportado ». Programa de Pós-Graduação em Química da UFBA, 2005. http://www.repositorio.ufba.br/ri/handle/ri/9950.
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O estireno é uma das substâncias químicas básicas mais importantes para produção de valiosos artigos como poliestireno, acrilonitrila-butadieno-estireno e estireno-butadieno-estireno. É produzido comercialmente pela desidrogenação do etilbenzeno com excesso de vapor d’água a temperaturas altas de 600-700ºC. Este processo é termodinamicamente limitado e consome energia. O uso de um oxidante, tal como oxigênio, permite superar as limitações termodinâmicas e por conseguinte operar a temperaturas mais baixas com reação exotérmica. Porém, há uma perda significantiva de seletividade a estireno, assim se buscou outro oxidante por muito tempo. O uso de gás carbônico surge como um potencial oxidante, além da conveniência do uso do gás causador do efeito estufa. Na busca de um catalisador alternativo para esta reação, neste trabalho estudou-se o efeito do método de preparação nas propriedades de óxido de ferro. As amostras foram preparadas incorporando óxido de ferro em lantânia, nióbia, titânia, magnésia e zircônia através de dois métodos: a impregnação de nitrato férrico e a deposição de nanoparticulas de óxido de ferro previamente preparadas. Os sólidos foram calcinados a 600ºC por 4 h e caracterizados por análise química, termogravimetria, análise térmica diferencial, difração de raios X, área de superfície específica e medidas de porosidade e redução a temperatura-programada. Os catalisadores foram avaliados na desidrogenação do etilbenzeno na presença de dióxido de carbono, usando um microreator que opera a 1 atm e a 600ºC e uma relação molar gás carbônico/etilbenzeno de 10. Depois dos testes, as amostras foram caracterizadas por difração de raios X e área de superfície específica. Observou-se que a concentração do óxido de ferro incorporado depende do tipo do suporte e do método de preparação. A hematita foi observada nos catalisadores novos. Durante a desidrogenação do etilbenzeno, os suportes não se alteraram, mas a hematita se transformou em magnetita. Os suportes e os catalisadores são sólidos macroporosos com pequena contribuição de mesoporos. A área específica mudou devido à adição de óxido de ferro e foi influenciada pelo método de preparação. A incorporação das nanoparticulas conduziu a um aumento da área superficial específica, indiferentemente do tipo do suporte, fato que foi atribuído ao tamanho pequeno das partículas. As áreas específicas não se alteraram durante a reação. Os sólidos mostraram diferentes resistência contra redução que se deve ao suporte e ao método de incorporação do óxido de ferro. A impregnação de nitrato férrico produziu sólidos menos redutíveis. Os suportes foram cataliticamente ativos na desidrogenação do etilbenzeno na presença de gás carbônico e também eram seletivos a estireno. A adição de compostos de ferro melhorou estas propriedades e a deposição de nanoparticulas melhoraram ainda mais. O óxido ferro suportado em magnésia, preparado pela deposição de nanoparticulas, foi o mais ativo (2,8 x 10-3 mol.g-1.h-1) e catalisador seletivo a estireno (96%) na desidrogenação do etilbenzeno na presença de gás carbônico. A atividade e a seletividade foram mais altos do que um catalisador comercial à base de óxido de ferro, cromo e potássio (a=1,2 x 10-3 mol. g-1. h-1 e S=90%) , sendo o catalisador promissor na reação.
Salvador
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RIBEIRO, THATIANA G. D. « Sintese e caracterizacao de nanoparticulas magneticas de oxidos mistos de MnFesub(2)Osub(4) recobertas comm quitosona. Estudos da influencia na dopagem com Gdsup(3+) nas propriedades estruturais e magneticas ». reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11515.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Bonfleur, Eloana Janice. « Matéria orgânica e a sorção de herbicidas em solos sob plantio direto nas regiões tropical e subtropical do Brasil ». Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-15092014-122141/.
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O sistema de plantio direto (SPD) é extensivamente utilizado no Brasil por tratar-se de prática conservacionista, capaz de melhorar a qualidade do solo e diminuir os custos da produção em relação ao plantio convencional. Neste sistema as condições edafoclimáticas distintas e a adoção de diferentes culturas na entressafra sugerem diferenças na distribuição e na qualidade da matéria orgânica de solos (MOS), devido ao tempo de resiliência da palha em cobertura. A interação entre a MOS e os pesticidas já foi bastante estudada, mas apenas parcialmente esclarecida uma vez que a maioria dos estudos considera a MOS como um compartimento homogêneo, ignorando o papel de seus diferentes componentes moleculares. Assim sendo, o objetivo principal deste trabalho é avaliar o efeito da composição, distribuição e interação com a fase mineral da MOS na sorção de herbicidas aplicados às culturas de soja e milho, sob sistema plantio direto em diferentes condições edafoclimáticas: tropical (Região Centro-Oeste) e subtropical (Região Sul). Os herbicidas alaclor, bentazon e imazetapir foram selecionados devido às suas importâncias junto a essas culturas e suas propriedades físico-químicas distintas. Para tal, soram amostrados 12 Latossolos, na camada de 0 a 5 cm excluindo a palha de superfície, sendo seis representativos do Estado do Paraná (clima subtropical) e seis representativos do Estado do Mato Grosso do Sul (clima tropical). A determinação dos atributos físico e químicos, formas de ferro e alumínio, estudo da qualidade da MOS por espectroscopia de Ressonância Nuclear Magnética do 13C e fracionamento físico dos solos foram os métodos utilizados. Foi observado maior acúmulo de carbono orgânico (C.O) nos solos subtropicais devido ao maior teor de óxidos de alumínio de baixa cristalinindade, além da maior precipitação. Para os solos de ambas as regiões, a estabilização da MOS ocorre através da formação de complexos nos agregados tamanho argila ( ~ 50% do teor de C.O). Em relação às interações com a fase mineral, observou-se que os óxidos de alumínio estão relacionados à proteção física da MOS enquanto que os óxidos de ferro parecem participar das reações de decomposição e humificação através da formação de complexos com grupos carboxílicos. Para o alaclor, a presença de formas de alumínio de baixa cristalinidade diminuiu a sua sorção a MOS, entretanto a sorção deste herbicida não foi correlacionada a nenhum grupo funcional. Para o bentazon, foi observada correlação positiva entre a sorção e materiais orgânicos mais decompostos e também, com o alumínio complexado a MOS. Para o imazetapir, houve correlações positivas com as formas de ferro e alumínio e o grupo funcional carboxil. Para os três herbicidas a maior sorção foi observada nos agregados de tamanho silte (53 a 2 ?m) e, de maneira geral, a sorção nos solos tropicais foi maior que nos subtropicais. O efeito da exposição de sítios de carga após o fracionamento físico dos solos foi evidente para o imazetapir incrementando sua sorção em comparação a sorção no solo inteiro o que evidencia a maior quantidade de sítios bloqueados nos solos tropicais.No-tillage System (NT) is widely used in Brazil due to improve soil quality and reduce production costs compared to conventional tillage. Different climatic conditions and the adoption of different cultures in the offseason suggest differences in the distribution and quality of soil organic matter (SOM) due to the resilience time of straw in coverage in NT. Interactions between SOM and pesticides has been widely studied, but only partially elucidated. In most of studies, the MOS as a homogeneous compartment and there is not the knowledge about the role of its various molecular components. Therefore, the aim of this work is to evaluate the effect of the composition, distribution and interaction with the mineral phase of SOM on sorption of herbicides applied to soybean and corn under no-tillage in tropical (Central-west) and subtropical (South Region) soils. Alachlor, bentazon and imazethapyr herbicides were selected because of its large use in these cultures and different physicochemical properties. For this, it was sampled 12 soils at 0-5 cm layer excluding the straw surface, six representing the Paraná State (subtropical) and six representative of Mato Grosso de Sul State (tropical). Physical and chemical attributes, iron and aluminum forms, study of quality of SOM by Nuclear Magnetic Resonance Spectroscopy of 13C and soil physical fractionation methods were used for this purpose. Greater accumulation of organic carbon (OC) was observed in subtropical soils due to higher low crystalline aluminum oxides contents, in addition to lower temperatures and higher moisture in this region. For soils of both regions, the SOM stabilization occurs through the formation of complexes in the clay fraction (~ 50 % of the OC content). Regarding interactions with the mineral phase, it was observed that aluminum oxides are related to physical protection of SOM while iron oxides appear to participate in the decomposition and humification reactions by forming complexes with carboxylic groups. For alachlor, low crystallinity aluminum forms decreased its MOS sorption but sorption of this herbicide was not correlated with any functional group. For bentazon, positive correlation was observed between sorption and more decomposed organic material and with the complexed aluminum in MOS. For imazethapyr, there were positive correlations with iron and aluminum forms and carboxyl functional group. For the three herbicides better sorption was observed in the silt size fractions (53-2 ?m) and in general, sorption in tropical was higher than in subtropical soils. The effect of charge sites exposure after soil physical fractionation was evident for imazethapyr increasing its sorption compared to the whole soil which shows the greatest amount of blocked sites in tropical soils.
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Pirani, Parisa. « Surface-Engineered Magnetic Nanoparticles for Sample Preparation and Analysis of Proteins and Peptides ». ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/2012.
Texte intégralRésumé :
Sample preparation as an essential step in mass spectrometry-based analysis, plays a critical role in proteomics studies. Magnetic nanoparticles (MNPs) have been widely used in protein and peptide sample preparation due to their magnetic properties, biocompatibility, easy synthesis and surface functionalization. MNPs loaded with analyte or analyte modification reagent can be easily separated from the reaction medium by an externally applied magnetic field. The small size of MNPs provides high analyte loading and extraction capacity. Additionally, MNP can be decorated with different functional groups to achieve selective modification or extraction of analyte. In this study we have utilized silica coated iron oxide magnetic nanoparticles (Fe3O4@SiO2 MNPs) for protein and peptide sample preparation.
Fluorescence-based methods were utilized for quantitative and qualitative characterization of N-hydrosucccinimidyl (NHS) ester groups on the surface of Fe3O4@SiO2 MNPs. Fluorophore Dansylcadaverine was conjugated to NHS ester functional groups. Fluorometric measurement of cleaved dansylcadaveine was employed to determine the number of NHS ester groups per MNPs that was found to be 2.6 × 102 and 3.4 × 103for 20 nm and 100 nm Fe3O4@SiO2 MNPrespectively. The efficiency of labeling native bovine serum albumin (BSA) by NHS ester coated Fe3O4@SiO2 MNPs was also explored in terms of maximizing the number of MNPs conjugated per BSA molecule or maximizing the number of BSA molecules conjugated per each MNP.
Lysine residues of apolipoprotein B-100 (apoB-100) on the surface of intact human low density lipoprotein (LDL) were labeled by NHS ester modified Fe3O4@SiO2 MNPs in aqueous solvents at room temperature. The MNP labeledapoB-100 was treated by SDS to remove lipids and then digested using trypsin. Tryptic peptides were eluted from MNPs by cleaving disulfide linkage between labeled peptides and MNPs. LC-MS/MS analysis found 28 peptides containing labeled lysine residues. These lysine residues should be on the solvent exposed surface of LDL since the large size of MNPs prevents contact of the labeling reagent to those lysines embedded inside the structure of LDL.
TCEP- immobilized Fe3O4@SiO2MNPs were fabricated and utilized for reduction of disulfide bonds in bovine pancreas insulin and two different cyclic peptides. Disulfide bonds were efficiently cleaved at room temperature in both organic and aqueous solvents confirmed by LC-MS/MS analysis of reduced/alkylated protein and peptides. Disulfide reduction and alkylation reactions was performed in one step and the reducing agent was simply separated from peptide and protein solution by magnetic separation.
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Verdugo, Ihl Max Robert. « Mineralogy and geochemistry of iron-oxides in the Olympic Dam IOCG-deposit and adjacent prospects, South Australia ». Thesis, 2020. http://hdl.handle.net/2440/129081.
Texte intégralRésumé :
Iron-oxide copper gold (IOCG) mineralisation is defined by an abundance of hematite and/or magnetite. The predominance of one Fe-oxide over the other and their textural relationships can, however, differ significantly within a single deposit or within the same metallogenic province, as a response to variations in the genetic conditions. Analysis of Fe-oxides, bridging scales of observation from deposit down to the nanoscale, highlights different formation conditions within deposits and prospects from the ~1.6 Ga Olympic Dam district, South Australia. In addition, Fe-oxides from the ~5.3-1.6 Ma El Laco Volcanic Complex (Chile), which are debated in terms of magmatic and/or hydrothermal origins, were analysed for comparison with those formed in IOCG systems. At Olympic Dam, a characteristic oscillatory-zoned hematite, containing up to wt% concentrations of U-W-Sn-Mo (‘granitophile’ elements), is the predominant Fe-oxide over the ~6 km-strike and ~2 km-depth of the breccia-hosted mineralisation. Complex textural and compositional zoning patterns within the hematite indicate overprinting and replacement of pre-existing minerals, including earlier hematite, during subsequent episodes of fluid-assisted brecciation and mineralisation. A diverse range of features at the micron- to nanoscale indicates that pseudomorphic replacement of hematite occurred via coupled dissolution and reprecipitation reactions leading to grain-scale (re)mobilisation of minor/trace elements. Primary geochemical signatures are nevertheless partially or selectively preserved. This allows the use of hematite as a reliable U-Pb geochronometer. Mineralogical-geochemical study of Fe-oxides from the outer shell, a weakly-mineralised domain between the host granite and the Olympic Dam orebody, allows for re-interpretation of deposit formation. Iron-oxide assemblages comprise oscillatory-zoned, silician magnetite, high field strength element-bearing hematite, and various interconversion products between the two oxides. Formation of such assemblages is associated with early alkali-calcic alteration (calc-silicate inclusions in silician magnetite), breakdown of magmatic Fe-Ti-oxides, and replacement of igneous magnetite by silician magnetite. Geochemical modelling at 400 °C suggests magnetite-replacement at pH/fO₂ conditions that coincide with stability shifts of K-feldspar → sericite, and ilmenite → rutile. Outer shell formation was initiated at the depth of granite emplacement (~6-8 km), following volatile release from fluids ponding at intrusion margins. Mineralisation continued during uplift to shallower depth, with cupola collapse following extensive fluid release that facilitated brecciation and orebody formation. Nanoscale analysis of Fe-oxides by scanning transmission electron microscopy using Z-contrast imaging and mapping provides further insights into ore-forming processes. Fingerprinting of fluid-mineral interactions during subsequent overprint of U-W-Sn-Mo-bearing hematite show that twins provide pathways for fluid percolation and trap elements exchanged during cycles of coupled dissolution-reprecipitation. Metal nanoparticles (NP) are also trapped within pores developed during transient porosity, which can be hosted by fluid inclusions. Unusual Cu-As-zoning at the micron-scale correlates with Cu-(As)-NPs along fluid inclusion trails and Si-Al-K-bearing twin planes linking such metal enrichment to hydrolytic alteration. W-Pb-enrichment occurs along 2-3 nm-wide twin crests and as W-(Pb)-bearing NPs in hematite displaying ‘granitophile element’-signature with preferential removal of W and preservation of Sn, as shown by grain-scale element patterns. A two-fold superstructure model with oxygen vacancies is constructed to explain W-release from hematite. Nanoscale features observed in relation to twins also allow prediction of disturbances to the U/Pb-systematics of hematite with implications for geochronology. Nanomineral inclusions in magnetite are valuable petrogenetic indicators that can clarify ore-forming processes. At Acropolis, vein titanomagnetite, within ~1.6 Ga volcanic rocks, features nanoscale inclusions with ulvöspinel-hercynite pairs and ilmenite-trellis exsolutions followed by subsequent overprinting (rutile replacement of Ti-phases). Spinel-group associations and ilmenite/magnetite oxythermobarometry supports hydrothermal-magnetite formation at ≥500 °C. Silician magnetite from Wirrda Well hosts nanoinclusions of the rare Al-amphibole, tschermakite. Considering the metamorphism of the host ~1.85 Ma granite, the presence of tschermakite could represents a metamorphic phase that crystallised prior to IOCG-style mineralisation. In contrast, magnetite from Fe-ores at El Laco contains nm-scale inclusions of paired clinopyroxenes (augite-pigeonite/clinoenstatite) with intergrowths indicative of rapid growth and exsolution at low pressures/high temperatures, typical of crystallisation from melts. Sulfur-bearing coatings on comparable but finer-grained pyroxene-bearing magnetite are indicative of ‘magnetite flotation’ via attachment to bubbles of vapour+fluid, allowing transport from a deep magma reservoir to surface. Iron-oxides show remarkable variation in compositional signatures and nanoscale heterogeneity. Detailed petrographic, geochemical and mineralogical analysis of Fe-oxides represents a rich and often untapped source of information that can assist in constraining ore formation conditions and contribute to improved genetic models.Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering and Advanced Materials, 2020
Chapitres de livres sur le sujet "Iron oxide NPs"
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Zoppellaro, Giorgio. « Iron Oxide Magnetic Nanoparticles (NPs) Tailored for Biomedical Applications ». Dans Magnetic Nanoheterostructures, 57–102. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-39923-8_2.
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Nadaroglu, Hayrunnisa, Semra Cicek, Hicran Onem et Azize Alayli Gungor. « The Investigation of Removing Direct Blue 15 Dye from Wastewater Using Magnetic Luffa sponge NPs ». Dans Iron Ores and Iron Oxide Materials. InTech, 2018. http://dx.doi.org/10.5772/intechopen.73216.
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Jahan, Israt. « Phyto-Nanofabrication ». Dans Handbook of Research on Green Synthesis and Applications of Nanomaterials, 51–76. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8936-6.ch003.
Texte intégralRésumé :
Green synthesis of metallic nanoparticles through natural entities (i.e., bacteria, actinomycetes, yeast, fungus, microalgae, seaweed, plants, and plant-derived materials) has become an advantageous and ecofriendly approach. However, phytocompounds of plant extract have achieved huge attention since by utilizing them high yield NPs with desirable size and shape, which can be produced through single-step synthesis scheme. Plants retain diverse biochemicals that exhibit strong hyper-accumulating potential, crucial for metallic ion reduction to metallic NPs, like platinum, gold, silver, titanium oxide, iron oxide, copper oxide, zinc oxide, palladium, etc. Here, previously published studies were reviewed for providing the latest scientific evidence on biosynthesis of metal and metal oxide NPs using different plant materials, especially medicinal plants and food and agro-wastes.
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Pullar, R. C. « Applications of Magnetic Oxide Nanoparticles in Hyperthermia ». Dans Magnetic Nanoparticles for Biomedical Applications, 76–101. Materials Research Forum LLC, 2023. http://dx.doi.org/10.21741/9781644902335-3.
Texte intégralRésumé :
Magnetic oxide nanoparticles (NPs) are probably the most common nanomaterials in everyday biomedicine, and have been in use since the 1990’s. They are usually magnetic iron oxide NPs, made of magnetite (Fe3O4) or maghemite (γ-Fe2O3), or a mixture of the two. Both of these have the spinel structure, and other spinel ferrites such as ZnFe2O4, CoFe2O4 and NiFe2O4 are also used. For applications in magnetic hyperthermia these NPs must be below the magnetic domain size, making them superparamagnetic, which means that their magnetisation can be “switched on” by the application of an external magnetic field. Magnetic hyperthermia treatment is a form of thermotherapy which is used to kill tumour cells with thermal energy (heat) in a very localised manner, by causing magnetic oxide NPs to heat up near tumour cells. Under an applied AC magnetic field the magnetic spin of the NPs switches rapidly in direction, transforming the magnetic energy into thermal energy. Temperatures of 41-46 °C are sufficient, this localised heating elevating the temperature of tumour cells, inhibiting growth, killing them, or inducing tumour cell apoptosis. Magnetic NPs were first used in tumour thermotherapy in 1996, and since then there has been a great deal of research in this field. The treatment can be applied alone, or used in combination with other therapies such as surgery, radiotherapy and chemotherapy, and it has shown excellent synergistic effects in combination with anticancer drugs (chemotherapeutics).
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Gárate-Vélez, Lorena, Claudia Escudero-Lourdes, Daniela Salado-Leza, Armando González-Sánchez, Ildemar Alvarado-Morales, Daniel Bahena, Gladis Judith Labrada-Delgado et José Luis Rodríguez-López. « Anthropogenic Iron Oxide Nanoparticles Induce Damage to Brain Microvascular Endothelial Cells Forming the Blood-Brain Barrier ». Dans Advances in Alzheimer’s Disease. IOS Press, 2021. http://dx.doi.org/10.3233/aiad210010.
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Background: Iron nanoparticles, mainly in magnetite phase (Fe3O4 NPs), are released to the environment in areas with high traffic density and braking frequency. Fe3O4 NPs were found in postmortem human brains and are assumed to get directly into the brain through the olfactory nerve. However, these pollution-derived NPs may also translocate from the lungs to the bloodstream and then, through the blood-brain barrier (BBB), into the brain inducing oxidative and inflammatory responses that contribute to neurodegeneration. Objective: To describe the interaction and toxicity of pollution-derived Fe3O4 NPs on primary rat brain microvascular endothelial cells (rBMECs), main constituents of in vitro BBB models. Methods: Synthetic bare Fe3O4 NPs that mimic the environmental ones (miFe3O4) were synthesized by co-precipitation and characterized using complementary techniques. The rBMECs were cultured in Transwell® plates. The NPs-cell interaction was evaluated through transmission electron microscopy and standard colorimetric in vitro assays. Results: The miFe3O4 NPs, with a mean diameter of 8.45 ± 0.14 nm, presented both magnetite and maghemite phases, and showed super-paramagnetic properties. Results suggest that miFe3O4 NPs are internalized by rBMECs through endocytosis and that they are able to cross the cells monolayer. The lowest miFe3O4 NPs concentration tested induced mid cytotoxicity in terms of 1) membrane integrity (LDH release) and 2) metabolic activity (MTS transformation). Conclusion: Pollution-derived Fe3O4 NPs may interact and cross the microvascular endothelial cells forming the BBB and cause biological damage.
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Karataş, Ebru, et Fehiman Çimer. « Green Synthesis of Nanoparticles and Their Applications ». Dans Versatile Approaches to Engineering and Applied Sciences : Materials and Methods. Özgür Yayınları, 2023. http://dx.doi.org/10.58830/ozgur.pub50.c70.
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Nanotechnology, which involves the synthesis, design and application of materials or devices with sizes in the 1-100 nm range, has been an important topic in various basic and applied sciences such as medicine, pharmacy, dentistry, chemistry, biology, environment and materials science. Nanotechnology, which has ease of application, is a new emerging technology. The rapid increase in nanotechnological research around the world in recent years has allowed the development of nanoscale devices and new materials. Nanotechnology has opened up new dimensions in the field of biotechnology and nanomedicine, among various other important applications such as drug delivery, electronics, cosmetics, personal care products and biosensors. Nanoparticles (NPs), which form the basis of nanotechnology, have remarkable properties such as specific sizes, surface structures, chemical compositions, large surface area volume ratios, electronic structure, and interfacial reactivity. As the sizes and shapes of NPs change, the physical, chemical, optical, electrical, thermal, catalytic, bioactivity and toxicity properties of the particles also change. NPs of various shapes and sizes are synthesized by three different methods as physical, chemical and biological. Synthesis of NPs by conventional methods such as physical and chemical methods causes high energy consumption, low efficiency, high cost and formation of toxic products. Green synthesis, which has been widely used recently, is a more cost-effective, easy to synthesize and environmentally friendly method using biological agents. Different natural and harmless biomaterials such as plants, plant extracts, fungi, algae, yeasts, bacteria, virus DNA are used for the biological synthesis of different NPs. With this method, the effect of chemicals is greatly reduced and their damage is eliminated as much as possible. In addition, it does not require high pressure and high temperature values. Many metals and metal oxide nanoparticles such as gold, zinc, silver, palladium, manganese, iron oxide, titanium dioxide, copper oxide and lead oxide are synthesized in a single step with the green synthesis method. The fact that the green synthesis method has many advantages compared to other processes and the continuous development of nanotechnology allows the green synthesis method to develop and be used more widely. The aim of this study is to reveal the importance of green synthesis, the biomaterials used in green synthesis, the properties and usage areas of synthesized NPs.
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Latha, Subbiah, Palanisamy Selvamani, Suresh Babu Palanisamy, Deepak B. Thimiri Govindaraj et Prabha Thangavelu. « Magnetic Nanoparticles ». Dans Handbook of Research on Nano-Strategies for Combatting Antimicrobial Resistance and Cancer, 337–69. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-5049-6.ch017.
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The magnetic nanoparticles are said to be a class of nanoparticles or nanomaterials that can be manipulated by the help of externally applied magnetic field. These magnetic nanoparticles constitute materials such as nickel, cobalt, iron, and their derivatives. These are normally smaller than 1 µm in diameter possess wide range of properties and attractive characteristics suitable for biomedical such as used as hyperthermia, enhancing magnetic resonance imaging (MRI) data, supplementing tissue engineering efforts, and improving the target-based drug delivery and many other technological applications. In the field of cancer research, the role of nanoparticles and nanotechnology-based methods and novel strategies have been increasing swiftly for cancer identification and cancer therapy. The iron oxide (Fe3O4, γ-Fe2O3) nanoparticles (NPs) are widely used for the drug delivery, magnetic nanoparticle-enhanced hyperthermia, and also as MRI contrast agents due to its biocompatibility, low toxicity, etc. lead to the growth of novel biopharmaceutical technologies.
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Chakrabartty, Shubhro, AlaaDdin Al-Shidaifat, Ramadan Al-Shdefat, M. I. Alam et Hanjung Song. « Drug and gene delivery by nanocarriers : Drug delivery process, in brief, using different oxides such as zinc, iron, calcium, polymeric, peptides, and in-vitro drug delivery process by silicon oxide (SiOx) and titanium dioxide (TiO2) nanodots (NDs) ». Dans Advances in Nanotechnology-Based Drug Delivery Systems, 281–320. Elsevier, 2022. http://dx.doi.org/10.1016/b978-0-323-88450-1.00022-3.
Texte intégralActes de conférences sur le sujet "Iron oxide NPs"
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Alvi, Muhammad Awais Ashfaq, Mesfin Belayneh, Kjell Kåre Fjelde, Arild Saasen et Sulalit Bandyopadhyay. « Effect of Hydrophobic Iron Oxide Nanoparticles on the Properties of Oil Based Drilling Fluid ». Dans ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18215.
Texte intégralRésumé :
Abstract In recent years, nanoparticles (NPs) have shown the potential to improve the performance of oil well fluids significantly. Several studies have reported the ability of NPs to produce improved properties of both water and oil-based drilling fluids. In this paper, hydrophobic iron oxide NPs were synthesized by thermal decomposition of iron pentacarbonyl in an inert atmosphere, and its performance was tested in the oil-based drilling fluid with 90/10 oil to water ratio (base fluid). Oil-based drilling fluids treated with nanofluids were formulated by adding 0.5 wt. % and 1.0 wt. % iron oxide NPs in hexane solution to the base drilling fluid. The base fluid and the nanofluid treated drilling fluids were evaluated by characterizing their rheological properties at different temperatures, viscoelastic properties, lubricity, filtrate loss, static & dynamic settling, and separation properties. Results showed that 0.5 wt. % iron oxide dispersed in hexane reduced the HPHT filtrate loss by 70%, filter cake thickness by 55%, and the coefficient of friction by 39%. Moreover, the nanofluid based drilling fluid reduced the free oil layer caused by syneresis during aging at high temperature by 16.3% compared to the base fluid. This study has shown that hydrophobic iron oxide NPs have the potential to improve the properties of oil-based drilling fluid.
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Kalambur, Venkat S., Ellen Longmire et John C. Bischof. « Characterization of Cell Association and Heat Treatment Using Iron Oxide Magnetic Nanoparticles ». Dans ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176216.
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Magnetic iron oxide nanoparticles (NPs) have intrinsic advantages over other NPs for various biomedical applications. These advantages include visualization under Magnetic Resonance Imaging (MRI), heating with Radiofrequency (RF), and movement in a magnetic field. There are now numerous efforts to expand the applications of these particles for non-invasive drug and adjuvant delivery, cellular imaging and in vitro cell sorting and purification. In the present study, we describe methods to (i) assess and quantify NP cell association (ii) facilitate NP heat destruction of cells after association with RF and laser. First, we show that (i) the cell association of iron oxide NPs is dependent on the surface coating (surfactant greater than dextran), time, cell-type and extracellular NP concentrations (saturation with concentration and time). Furthermore, the association fits a simple enzyme Michealis-Menten model. Second, (ii) improved heat destruction of cells can be achieved after laser irradiation compared to traditional RF treatment for similar NP associations. These results and assays show promise for cell sorting and purification applications.
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Balezin, M. E., et S. Yu Sokovnin. « Production of iron oxide nanopowders by radiation-chemical method ». Dans 8th International Congress on Energy Fluxes and Radiation Effects. Crossref, 2022. http://dx.doi.org/10.56761/efre2022.s4-p-042405.
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Were continued the studies of nanopowders (NP) of iron oxide produced by radiation-chemical method at irradiation of iron sulfate solutions in water and iron nitrate in isopropyl alcohol on electron accelerator URT-0,5. With an increase in the concentration of iron sulfate in the solution, the specific surface area of the NP decreases, and the yield increases. For iron nitrate, with an increase in its concentration in solution, both the yield of NP and the specific surface area grow under irradiation under the same conditions (absorbed dose of 2.3 MGy at an accelerator frequency of 10 Hz). Since the particles produced from the iron nitrate solutions are amorphous, they were annealed, followed by X-ray phase analysis. It has been found that these are hematite, Fe2O3particles (unlike maghemite C, γ- Fe21.33O32particles from iron sulfate). The specific surface area of the particles increases with the annealing temperature (from 2.4 nm at 400°C to >> 200 nm at 1200°C). The produced NPs can be used to create promising upconversion materials for medicine based on them.
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Altayeb, Yousra Bashir Fathalrhman, et Ecir Yılmaz. « Oral Squamous Cell Carcinoma (OSCC) Treatment by Magneti Nanoparticles (Hyperthermia Method) : A Review ». Dans 6th International Students Science Congress. Izmir International Guest Student Association, 2022. http://dx.doi.org/10.52460/issc.2022.020.
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Squamous cell carcinoma (SCC) is the most commonly diagnosed oral cancer. It is a type of head and neck squamous cell carcinoma (HNSCC) oral cancer affects more than 300,000 people in a year. Oral cancer is the sixth most common malignant cancer. The traditional methods of treatment were used through surgery, followed by chemotherapy, but these methods are not effective enough for the treatment, so treatment was focused on using magnetic nanoparticles. Magnetic nanoparticles demolish only the cancer cells directly without affecting healthy cells. They can also be used to increase the effectiveness of the other treatment methods. Iron oxide nanoparticles, maghemite (Fe2O3) and magnetite (Fe3O4) are widely used in the diagnosis and treatment of cancerous diseases. Iron oxides NPs have distinctive properties as they have good biodegradability, very low toxicity, modifiability, and ease of preparation. the method of hyperthermia is one of the effective methods in the treatment of cancer. Because cancer cells show greater sensitivity to high temperature compared to normal cells.
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Alsakkaf, Sarah, Sahar Al-Dosary, Hesham El-Komy et Mona Al. Ahmadi. « Effect of Different Nanoparticles Silver, Iron Oxide and Titanium Oxide to Control Corrosion by Desulfovibrio Sp.Isolated from Oil Fields ». Dans International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-22588-ms.
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Abstract Microbiologically influenced corrosion (MIC), or biocorrosion is a corrosion of metals in environment containing microorganism. The microorganisms can initiate corrosion or accelerate by their metabolic activities. Recently, MIC problems common in oil recovery which depend on seawater injection. Many of researchers have been investigated that Sulfate-reducing bacteria (SRB) is the major groups of microorganisms that cause corrosion. Pitting corrosion and sulfide generation in oil and gas fields are correlated to presence of SRB. Last decade, nanotechnology is alternative biocide of chlorine-free. Metal nanoparticles improve the antimicrobial activity of the metals. The biocidal activity of AgNPs, Fe2O3NPs and TiO2NPs against Desulfovibrio sp. (St.7) at 1 ppm, 50 ppm and 100 ppm concentrations as estimated by cell growth and H2S production was examined. AgNPs and Fe2O3NPs had no significant effect at a low concentration, 1 ppm, on both bacterial growth and sulfide production. Whereas, increasing NPs concentration to 50 ppm and 100 ppm led to a complete inhibition of both growth and sulfide production. TiO2NPs gave complete inhibitory effect on both growth and H2S production by Desulfovibrio sp. (St.7) at all the tested concentrations (1ppm, 50ppm, 100ppm). The study supports the use of such nanoparticles as a green biocide and safe method to control corrosion problem caused by sulphate reducing bacteria.
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Alvi, Muhammad Awais Ashfaq, Mesfin Belayneh, Arild Saasen et Sulalit Bandyopadhyay. « Impact of Various Nanoparticles on the Viscous Properties of Water Based Drilling Fluids ». Dans ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/omae2021-62612.
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Abstract Properly designed drilling fluid is a key element in achieving safe and effective drilling operations. Rheological parameters of drilling fluid determine the equivalent circulation density, the pump pressure, and hole cleaning efficiency. Also, they have a significant role in predicting the stability of drilling fluid under static and low shear rates. The chemical composition of the drilling fluid controls the rheological parameters. Recently, studies have shown that a small concentration of nanosized materials in the drilling fluid can substantially impact the rheological parameters of the drilling fluids. In this study, various nanoparticles (NPs) with different shapes, sizes, and surface charges were used to investigate their impact on the viscous properties of water-based drilling fluid. Bentonite and KCl water-based drilling fluids were used as the base fluids. NPs such as Iron oxide, Silica (SiO2), and multi-walled carbon nanotubes (MWCNT) were added to these base fluids. Also, surface functionalization of the NPs with polymer and functional groups such as -OH and -COOH groups was done to compare the effect of bare NPs with surface functionalized NPs. Hershel-Buckley model with dimensionless shear rates was used to calculate the low and high shear curvature exponents, surplus stress, and yield stress of the samples. Results indicate that NPs alter drilling fluid’s viscous properties based on their sizes, shapes, and surface charges. Moreover, the functionalization of NPs also modifies the properties based on the functional group attached to the NPs surface. This work shows that changing the size, shape, and surface charge of NPs has impact on viscous parameters, and NPs with different properties can fine-tune the fluid’s viscous properties based on the requirement for drilling fluid.
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Islam, Nazmul, Davood Askari et Tarek Trad. « Biocompatible Nanocomposite for Lab-on-a-Chip Application ». Dans ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-64119.
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Lab-on-a-chip (LOC) devices integrate multiple laboratory functions and processes to a miniaturized chip format. Many LOC devices are used in a wide range of biomedical and other analytical applications including rapid pathogen detection, clinical diagnosis, electrophoresis, flow cytometry, and protein and DNA analysis. LOC devices can be fabricated from many types of material including various polymers, glass/silicon, or combinations of these materials. A broad variety of fabrication technologies are used for LOC device fabrication. LOC systems have several common features including microfluidics (e.g. channels, micro-pumps, mixers and valves) and sensing capabilities. This paper describes a technique for the fabrication of a micro-pump that can be used in implantable biocompatible devices. This paper will also discuss the synthesis and properties of biocompatible iron oxide nanoparticles (NPs) for AC electrokinetic micro-pumping. Iron oxide NP will be incorporated with PDMS (polydimithylsiloxane) to obtain biocompatible nanocomposite. The use of photoluminescence, hydrophobic, and reflective optical response of these materials for in-vitro and in-vivo sensing and micro-pumping will be highlighted.
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Kachoyan, Soroush, Shaikh Nihaal, Jeffrey Oseh, Mohd Noorul Anam, Afeez Gbadamosi, Augustine Agi et Radzuan Junin. « Enhanced Rheological and Filtration Properties of Water-Based Mud Using Iron Oxide and Polyanionic Cellulose Nanoparticles ». Dans SPE Nigeria Annual International Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/211924-ms.
Texte intégralRésumé :
Abstract The unstable wellbore created by the infiltration of drilling fluids into the reservoir formation is a great challenge in drilling operations. Reducing the fluid infiltration using nanoparticles (NPs) brings about a significant improvement in drilling operation. Herein, a mixture of iron oxide nanoparticle (IONP) and polyanionic cellulose nanoparticle (nano-PAC) additives were added to water-based mud (WBM) to determine their impact on rheological and filtration properties measured at 80 °F, 100 °F, and 250 °F. Polyanionic cellulose (PAC-R) was processed into nano-PAC by wet ball-milling process. The rheological behaviour, low-pressure low-temperature (LPLT), and high-pressure high-temperature (HPHT) filtration properties performance of IONP, nano-PAC, and IONP and nano-PAC mixtures were compared in the WBM. The results showed that IONP, nano-PAC, and synergy effect of IONP and nano-PAC in WBM at temperatures of 80 °F and 250 °F improved the density, 10-s and 10-min gel strength (10-s Gs and 10-min GS), plastic viscosity (PV), and the yield point (YP), while the pH was constant at 9.0. The mixture of 1.5 wt.% IONP + 0.25g nano-PAC in the WBM unveiled the most promising and optimal properties. At LPLT, the mixture improved the YP by 11% and reduced the LPLT fluid loss volume (FL) by 32.4%. At HPHT, the mud density increased by 3%, 10-s GS by 56%, 10-min GS by 52%, and the YP by 33.3%, while the HPHT FL decreased by 21%. With 1.0 g concentration at 100 °F, the nano-PAC achieved the greatest reduction in the FL of the WBM by 63%, followed by PAC-R by 57% before IONP that showed 36% reduction. Overall, the impact of IONP and nano-PAC in the WBM is evident and while the IONP showed more improved PV, the nano-PAC is more desirable for fluid loss control when 1.0 g at 100 °F was used. The use of combined IONP and nano-PAC could be beneficial for mitigating fluid loss and averting wellbore problem.
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AlJabri, Nouf, Hussain Shatteb, Mustafa Saffar et Amr AbdelFattah. « Magnetically Labelled Hybrid Nanosurfactant MLHNS for Upstream Oil and Gas Operations ». Dans SPE Middle East Oil & Gas Show and Conference. SPE, 2021. http://dx.doi.org/10.2118/204843-ms.
Texte intégralRésumé :
Abstract Nanoencapsulation and targeted chemical delivery techniques have transformed many fields such as pharmaceutical drug delivery for medical treatment and diagnosis, and can similarly transform several upstream oil and gas operations. This paper describes the dual nanoencapsulation of superparamagnetic iron oxide nanoparticles (SPOINs) and petroleum sulfonate surfactants to produce hybrid nanosurfactant (MLHNS) in high-salinity water (56,000 ppm) using an inexpensive, scalable, and straightforward synthesis protocol. This novel magnetically labelled nanofluid (NF) is designed to: 1) enhance the residual oil mobilization via altering the rocks wettability and reducing the interfacial tension, and 2) enable in-situ monitoring of injected fluids when combined with EM surveys. NFs encapsulating a petroleum sulfonate surfactant and three different concentrations of 5-nm SPOINs were prepared using a two-step nanoencapsulation method. Both colloidal and chemical stability of the prepared formulations were tested at 90 °C for over a year. Results showed that all the formulations exhibited remarkable long-term colloidal and chemical stability under these close-to-reservoir conditions. Transition electron microscopy (TEM) images confirmed the encapsulation of SPIONs. The SPOINs-NFs have successfully reduced the interfacial tension (IFT) between crude oil and water by more than three orders of magnitude (from ~ 25 mN/m down to ~ 0.01 mN/m). These IFT and stability results demonstrate a strong synergy between SPIONs and the petroleum sulfonate surfactant. It is worth mentioning that this novel encapsulation platform enables the encapsulation of a wide range of nanoparticles (NPs) to generate a library of multi-function NFs to support several upstream applications.
Rapports d'organisations sur le sujet "Iron oxide NPs"
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Jackson, G. D. Bedrock geology, northwest part of Nuluujaak Mountain, Baffin Island, Nunavut, part of NTS 37-G/5. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/314670.
Texte intégralRésumé :
The map area lies about 40 km northwest of Baffinland's iron mine. Dykes of unit mAnA3 within unit mAnA2 suggest that unit mAnA2 predates unit mAnA3. Unit nAMqf, basal Mary River Group unit, includes regolith material from units mAnA2 and mAnA3. Unit mAnAm may include some dykes of unit nAMb. The Mary River Group was deposited in a volcanic-arc environment, yielding zircon U-Pb ages mostly in the range of 2.88 to 2.72 Ga. Iron-formation (unit nAMi) is approximately 276 m thick locally, with oxide facies (unit nAMio) being most abundant. The quartzite triangle west of 'Iron lake' (unofficial name) may be a small horst. The main east-west-trending synclinal fold, including the area around 'Iron lake' and the no. 4 ore deposit, is upright, nearly isoclinal, and plunges mostly easterly at both ends with small scale anticlines and synclines in the middle. Magnetite constitutes about 75% of high-grade iron deposits in the north limb, whereas hematite predominates in south-limb deposits. K-Ar and Rb-Sr ages indicate middle Paleoproterozoic overprinting. Central Borden Fault Zone was active at ca. 1.27 Ga and during or after Ordovician time. Note: please be aware that the information contained in CGM 408 is based on legacy data from the 1960-1990s and that it has been superseded by regional-scale information contained in CGM 403.