Real-Space Transmission Electron Microscopy Investigations of Attachment of Functionalized Magnetic Nanoparticles to DNA-Coils Acting as a Biosensor

2010 ◽  
Vol 114 (41) ◽  
pp. 13255-13262 ◽  
Author(s):  
Sultan Akhtar ◽  
Mattias Strömberg ◽  
Teresa Zardán Gómez de la Torre ◽  
Camilla Russell ◽  
Klas Gunnarsson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Real Space ◽  
Transmission Electron ◽  
Functionalized Magnetic Nanoparticles

scholarly journals Probing planar defects in nanoparticle superlattices by 3D small-angle electron diffraction tomography and real space imaging

Nanoscale ◽  
2014 ◽  
Vol 6 (22) ◽  
pp. 13803-13808 ◽  
Author(s):  
Arnaud Mayence ◽  
Dong Wang ◽  
German Salazar-Alvarez ◽  
Peter Oleynikov ◽  
Lennart Bergström
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Real Space ◽  
Diffraction Tomography ◽  
Planar Defects ◽  
Pd Nanoparticle ◽  
Transmission Electron ◽  
Nanoparticle Superlattices ◽  
Microscopy Techniques

Planar defects in Pd nanoparticle superlattices were revealed by a combination of real and reciprocal space transmission electron microscopy techniques. 3D electron diffraction tomography was extended to characterize mesoscale imperfections.

Imaging of Buried Si and Si:Ge Surface Structure Under Amorphous Ge Films by Plan View Transmission Electron Microscopy

1994 ◽  
Vol 332 ◽  
Author(s):  
Olof C. Hellman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Shift ◽  
Room Temperature ◽  
Real Space ◽  
Interfacial Structure ◽  
Tem Analysis ◽  
Plan View ◽  
Transmission Electron ◽  
Reconstructed Surface

ABSTRACTReal space plan-view Transmission Electron Microscopy (TEM) of the interfacial structure at the amorphous-Ge / Si (111) interface is presented. Ge is deposited at between room temperature and 150°C on either a 5×5 or 7×7 reconstructed surface. Conventional Plan-view TEM analysis reveals microstructural details such as surface steps, reconstruction phase shift boundaries and the reconstruction itself buried under the amorphous film, features which have previously been seen only as clean surfaces in UHV. Also imaged are small regions where Ge grows epitaxially on the Si surface above room temperature. These are seen to appear preferentially at steps and phase shift boundaries.

Characterization of Magnetic Nanoparticles Using Energy-Selected Transmission Electron Microscopy

2002 ◽  
Vol 8 (5) ◽  
pp. 403-411 ◽  
Author(s):  
María J. Sayagués ◽  
Teresa C. Rojas ◽  
Asunción Fernández ◽  
Rafal E. Dunin-Borkowski ◽  
Ron C. Doole ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Magnetic Nanoparticles ◽  
Inert Gas ◽  
Sonochemical Method ◽  
Nano Composite ◽  
Transmission Electron ◽  
Metal Oxide Layer

Fe, Co, and Ni magnetic nanoparticles have been characterized using energy-selected imaging in a high-resolution transmission electron microscope. The samples comprised Fe/FeOx and Co/CoOx nanoparticles synthesized by inert gas evaporation and a Ni/C nano-composite prepared by a sonochemical method. All of the particles examined were found to be between 5 and 30 nm in size, with the Fe and Co crystals coated in 5–10 nm of metal oxide layer and the Ni metallic crystallites embedded in an amorphous carbon spherical matrix.

Transmission electron microscopy of C70 single crystals at room temperature

1992 ◽  
Vol 7 (9) ◽  
pp. 2440-2446 ◽  
Author(s):  
Vinayak P. Dravid ◽  
Xiwei Lin ◽  
Hong Zhang ◽  
Shengzhong Liu ◽  
Manfred M. Kappes
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Three Dimensional ◽  
Real Space ◽  
Acceptable Error ◽  
Hexagonal Close Packed ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Hcp Structure

Transmission electron microscopy (TEM) techniques have been employed to study the room temperature solid state form of chromatographically purified C70. Tilting and electron diffraction experiments in three-dimensional reciprocal space, on samples prepared by crystallization from several different solvents, show that C70 crystallites adopt hexagonal close packed (hcp) structure with a = 1.01 ± 0.05 nm and c = 1.70 ± 0.08 nm. The extinctions and observed reflections conform to the P63/mmc space group. High resolution TEM images reveal the molecular order and periodicity associated with C70 crystallites in real space. The experimental results are in agreement with the preliminary computations of crystal structure within acceptable error limits.

scholarly journals Silica-coated Magnetic Nanoparticles Activate Microglia and Induce Neurotoxic D-Serine Secretion

2021 ◽  
Author(s):  
Tae Hwan Shin ◽  
Da Yeon Lee ◽  
Balachandran Manavalan ◽  
Shaherin Basith ◽  
Yun-Cheol Na ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Amino Acid ◽  
Magnetic Nanoparticles ◽  
Mouse Brain ◽  
Cortical Neurons ◽  
Neuronal Cells ◽  
Primary Microglia ◽  
Transmission Electron ◽  
Amino Acid Profiling

Abstract BackgroundNanoparticles have been studied for brain imaging, diagnosis, and drug delivery owing to their versatile properties due to their small sizes. However, there are growing concerns that nanoparticles may exert toxic effects in the brain. In this study, we assessed direct nanotoxicity on microglia, the resident macrophages of the central nervous system, and indirect toxicity on neuronal cells exerted by silica-coated magnetic nanoparticles containing rhodamine B isothiocyanate dye [MNPs@SiO2(RITC)]. MethodsWe investigated MNPs@SiO2(RITC)-induced biological changes in BV2 murine microglial cells via RNA-sequencing-based transcriptome analysis and gas chromatography-mass spectrometry-based intracellular and extracellular amino acid profiling. Morphological changes were analyzed by transmission electron microscopy. Indirect effects of MNPs@SiO2(RITC) on neuronal cells were assessed by Transwell-based coculture with MNPs@SiO2(RITC)-treated microglia. MNPs@SiO2(RITC)-induced biological changes in the mouse brain in vivo were examined by immunohistochemical analysis.ResultsBV2 murine microglial cells were morphologically activated and the expression of Iba1, an activation marker protein, was increased after MNPs@SiO2(RITC) treatment. transmission electron microscopy analysis revealed lysosomal accumulation of MNPs@SiO2(RITC) and the formation of vesicle-like structures in MNPs@SiO2(RITC)-treated BV2 cells. The expression of several genes related to metabolism and inflammation were altered in 0.1 µg/µl MNPs@SiO2(RITC)-treated microglia when compared with that in non-treated (control) and 0.01 µg/µl MNPs@SiO2(RITC)-treated microglia. Combined transcriptome and amino acid profiling analyses revealed that the transport of serine family amino acids, including glycine, cysteine, and serine, was enhanced. However, only serine was increased in the growth medium of activated microglia; especially, excitotoxic d-serine secretion from primary rat microglia was the most strongly enhanced. Activated primary microglia reduced intracellular ATP levels and proteasome activity in cocultured neuronal cells, especially in primary cortical neurons, via d-serine secretion. Moreover, ubiquitinated proteins accumulated and inclusion bodies were increased in primary dopaminergic and cortical neurons cocultured with activated primary microglia. In vivo, MNPs@SiO2(RITC), d-serine, and ubiquitin aggresomes were distributed in the MNPs@SiO2(RITC)-treated mouse brain. ConclusionsMNPs@SiO2(RITC)-induced activation of microglia triggers excitotoxicity in neurons via d-serine secretion, highlighting the importance of neurotoxicity mechanisms incurred by nanoparticle-induced microglial activation.

Langmuir Layers of Magnetic Nanoparticles

2005 ◽  
Vol 877 ◽  
Author(s):  
Sara A. Majetich ◽  
Madhur Sachan ◽  
Shihai Kan ◽  
Yuhang Cheng ◽  
Julie Gardener
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Self Assembly ◽  
Magnetic Nanoparticle ◽  
Driving Forces ◽  
Transmission Electron ◽  
Carbon Coated ◽  
Co Nanoparticles

AbstractMethods to form magnetic nanoparticle monolayers using non-aqueous Langmuir layers are reported. Following a discussion of the driving forces in various self-assembly techniques, we describe how aqueous Langmuir layers can be modified for use in conjunction with oxidationsensitive nanoparticles. Monolayers are formed using Fe and–Co nanoparticles, and transferred to carbon-coated transmission electron microscopy grids using the Langmuir-Schaefer method.

Internalization of DMSA-Coated Fe3O4 Magnetic Nanoparticles into Mouse Macrophage Cells

2012 ◽  
Vol 455-456 ◽  
pp. 1221-1227
Author(s):  
Ying Xun Liu ◽  
Zhong Ping Chen ◽  
Jin Ke Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Cell Viability ◽  
Prussian Blue ◽  
Biomedical Applications ◽  
Blue Staining ◽  
Mouse Macrophage ◽  
Cytoplasmic Inclusions ◽  
Transmission Electron

This study observed the internalization of Fe3O4magnetic nanoparticles (MNPs) coated with meso-2, -3-dimercaptosuccinnic acid (DMSA) into mouse macrophage RAW264.7 by using transmission electron microscopy (TEM) and Prussian blue staining. The results showed that the DMSA-coated Fe3O4MNPs could be efficiently internalized into RAW264.7 cells. The internalized DMSA-coated Fe3O4MNPs located in the cytoplasmic inclusions. The internalization of DMSA-coated Fe3O4MNPs did not significantly affect the cell viability at given doses (20, 30, 40, 50 and 100 μg/mL) and incubation times (2, 12, 24, 48 and 72 hours), suggesting DMSA-coated Fe3O4MNPs had better biocompatibility. This study demonstrated that DMSA-coated Fe3O4MNPs may provide a potential nanomaterial for biomedical applications.

scholarly journals Combining powder diffraction with TEM for solving modulated structures

2014 ◽  
Vol 70 (a1) ◽  
pp. C135-C135
Author(s):  
Artem Abakumov
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Real Space ◽  
Space Structure ◽  
Electron Diffraction Data ◽  
Powder Diffraction Data ◽  
Transmission Electron ◽  
Modulated Structures

In many materials competing interactions of different nature may give rise to incommensurate modulations causing extreme structure complexity. Ab initio solution of the modulated structures even with using high quality synchrotron X-ray and/or neutron powder diffraction data appears to be a very challenging problem due to weakness of the satellite reflections, ambiguity in the determination of the modulation vector(s) and superspace symmetry and difficulties in building the initial model for further Rietveld refinement. These problems can be resolved or, at least, mitigated if the diffraction, imaging and spectroscopic advanced transmission electron microscopy techniques are combined with the analysis of powder diffraction data. Complete reconstruction of the reciprocal space, structure solution using quasi-kinematical electron diffraction data, mapping projected scattering density in the unit cell, visualization of the light atoms, displacive and occupational ordering, mapping chemical composition and coordination number can be utilized to reveal the nature of incommensurate modulations and construct the reliable model for the refinement from powder diffraction data. The benefit of the strategy of combining the powder diffraction data with the reciprocal and real space information obtained using aberration-corrected scanning transmission electron microscopy will be illustrated on the examples of the transition metal oxides: Li3xNd2/3-xTiO3 perovskites with frustrated incommensurately modulated octahedral tilting pattern [1]; perovskites (Bi,Pb)1-xFe1+xO3-y, modulated by crystallographic shear planes [2]; CaGd2(1-x)Eu2x(MoO4)4(1-y)(WO4)4y scheelites with incommensurately modulated ordering of cation vacancies [3].

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