Low-energy-loss EFTEM imaging of thick particles and aggregates

Valadares, Leonardo Fonseca; Bragança, Fábio do Carmo; Silva, Cristiane Aparecida da; Leite, Carlos A. P.; Galembeck, Fernando

doi:10.1016/j.jcis.2006.12.059

Cited by 18 publications

(18 citation statements)

References 28 publications

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“…21 It is well recognized that titanium degradation products including Ti(IV) ions are released by biocorrosion and accumulate in lymphoid tissues. 11,13,14,22,23 However, this is the first study using EFTEM analysis, which is recognized as the gold standard in identifying titanium availability in biological specimens, 24 to demonstrate the ability of human T-lymphocytes to take up Ti(IV). EFTEM results indicate a strong Ti(IV) affinity for phosphorus-containing molecules such as the euchromatin in the nucleus, ribosomes in the cytoplasm, and phospholipids in the cell membrane.…”

Section: Discussionmentioning

confidence: 99%

Titanium uptake, induction of RANK‐L expression, and enhanced proliferation of human T‐lymphocytes

Cadosch

Sutanto

Chan

et al. 2009

Journal Orthopaedic Research

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There is increasing evidence that titanium ions are released from orthopedic implants by biocorrosion. The aim of this study was to investigate titanium uptake by human T-lymphocytes and its effects on phenotype and proliferation. Freshly isolated human nonadherent peripheral blood mononuclear cells (NA-PBMC), were exposed to TiCl 4 [Ti(IV)]. Bioavailability and distribution of Ti(IV) in T-lymphocytes was determined by energy-filtered electron microscopy (EFTEM). The effects of Ti(IV) challenge on nonactivated and PHA-activated cells were assessed by flow cytometric analysis of surface markers, RANK-L production, and proliferation assays. EFTEM colocalized Ti(IV) with phosphorus in the nucleus, ribosomes, cytoplasmic membranes, and the surface membrane of T-lymphocytes. Ti(IV) increased significantly the expression of CD69, CCR4, and RANK-L in a concentration-dependent manner. Titanium enters T-lymphocytes through a currently unknown mechanism and binds to phosphorus-rich cell structures. Titanium influences phenotype and function of T-lymphocytes, resulting in activation of a CD69þ and CCR4þ T-lymphocyte population and secretion of RANK-L. These results strongly suggest the involvement of titanium ions challenged T-lymphocytes in the complex pathophysiological mechanisms of aseptic loosening of orthopedic implants. ß

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Section: Discussionmentioning

confidence: 99%

Titanium uptake, induction of RANK‐L expression, and enhanced proliferation of human T‐lymphocytes

Cadosch

Sutanto

Chan

et al. 2009

Journal Orthopaedic Research

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“…Energy-filtered imaging in the transmission electron microscope, EFTEM, can be used in the low-energy-loss region to provide information on the distribution of chemical constituents within large particles and particle aggregates, as reported recently [45]. Inner morphological features which cannot be observed in bright-field mode are easily detected using low-energy-loss images from the same field.…”

Section: Magnetic Mesoporous Particlesmentioning

confidence: 99%

Synthesis and characterization of magnetic mesoporous particles

Morales

Mascarenhas

Gomes

et al. 2010

Journal of Colloid and Interface Science

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Magnetic mesoporous particles were synthesized and their magnetic and structural properties are reported. The synthesis procedure consists of four steps: (i) preparation of magnetite colloidal nanoparticles; (ii) growth of a silica layer; (iii) development of the mesoporous structure and (iv) template removal. Two different methods for the template removal were studied and their effectiveness was discussed. Magnetization and Mössbauer spectroscopy measurements showed superparamagnetic behavior for the particles at room temperature. X-ray diffraction and nitrogen adsorption measurements showed a mesoporous MCM-41 structure with 2.48nm pore diameter and 1023m(2)/g total area.

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“…To make the examination of these complex systems it has been necessary to develop especial analytical TEM techniques and this group has recently made two methodological contributions in this direction, both based on the use of energy-filtered TEM (EFTEM). The first was the demonstration that thick cuts may be imaged producing significant information on component packing in large particle aggregates 44 and the other was a technique for molecular mapping 26 that allows the distinction of domains Vol. 20, No.…”

Section: A Paradigm For New Materials From Renewable Resourcesmentioning

confidence: 99%

Nanostructures and adhesion in natural rubber: new era for a classic

Rippel¹,

Galembeck²

2009

J. Braz. Chem. Soc.

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A borracha natural é obtida da Hevea brasiliensis, uma árvore nativa da floresta amazônica. Ela tem tido grande importância econômica há mais de 150 anos, sendo uma rica fonte de aprendizagem sobre polímeros e materiais poliméricos. Suas notáveis propriedades e vantagens sobre borrachas sintéticas atraíram a atenção de muitos pesquisadores que identificaram várias singularidades estruturais. Hoje, está claro que a borracha natural é um complexo material nanoestruturado, formado por poli(cis-1,4-isopreno), proteínas, fosfolipídios e vários componentes minerais minoritários. A contribuição dos autores para esta aprendizagem está resenhada neste artigo e abriu o caminho para o desenvolvimento de novos nanocompósitos, usando processos suaves e "verdes", dentro de um novo paradigma para a fabricação de materiais derivados de fontes renováveis. Natural rubber is obtained from Hevea brasiliensis, a tree that is native from the Amazon forest. It has been economically important for the past 150 years and it has also been a rich source of learning on polymers and polymeric materials. Its outstanding properties and advantages over synthetic rubbers have attracted the attention of many researchers that unraveled many contributing factors. Now, it is clear that natural rubber is a complex nanostructured material formed by poly(cis-1,4-isoprene), protein, phospholipids and a host of mineral minor components. Contribution of the authors to knowledge on natural rubber is reviewed in this paper and it opened the way to develop a host of new nanocomposites, using mild, "green" processes, within a new paradigm for the fabrication of materials derived from renewable sources.

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Low-energy-loss EFTEM imaging of thick particles and aggregates

Cited by 18 publications

References 28 publications

Titanium uptake, induction of RANK‐L expression, and enhanced proliferation of human T‐lymphocytes

Titanium uptake, induction of RANK‐L expression, and enhanced proliferation of human T‐lymphocytes

Synthesis and characterization of magnetic mesoporous particles

Nanostructures and adhesion in natural rubber: new era for a classic

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