scholarly journals Детектирование клеток, содержащих интернализованные мультидоменные магнитные наночастицы оксида железа (II, III), методом магнитно-резонансной томографии

2020 ◽  
Vol 90 (9) ◽  
pp. 1418
Author(s):  
Н.И. Енукашвили ◽  
И.Е. Коткас ◽  
Д.С. Боголюбов ◽  
А.В. Котова ◽  
И.О. Боголюбова ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Culture Medium ◽  
Electric Explosion ◽  
Particle Sizes ◽  
Relaxation Mode ◽  
T1 Relaxation ◽  
Transmission Electron ◽  
Wide Range ◽  
Magnetic Resonance Imaging Mri ◽  
Clinical Mri

This study evaluated the feasibility of using uncoated iron (II, III) oxide nanoparticles (IONP) obtained by electric explosion of wire in air for labelling living mesenchymal stromal cells and their subsequent visualization by magnetic resonance imaging (MRI) using 1.5T clinical MRI scanners. The uptake of uncoated IONP by MSC was demonstrated for the wide range of IONP concentration in the cell culture medium. The cells did not change their proliferative activity, viability, and the set of surface markers. IONP obtained by electric explosion of wire in an atmosphere of air had a shape close to spherical. The size of nanoparticles varied from 14 to 136 nm according to dynamic lateral light scattering, laser diffraction, and transmission electron microscopy. Particles up to 136 nm comprised 75%, and particles less than 36 nm --- 10% of the IONP powder. A wide range of particle sizes made it possible to select MRI parameters suitable for labelled cells detection in animal tissues both in the T2 mode and in the T1 relaxation mode.

scholarly journals A green chemical route for the synthesis of Mn3O4 nanoparticles

2009 ◽  
Vol 7 (3) ◽  
pp. 555-559 ◽  
Author(s):  
Zehra Durmus ◽  
Hüseyin Kavas ◽  
Abdulhadi Baykal ◽  
Muhammet Toprak
Keyword(s):  
Room Temperature ◽  
Particle Sizes ◽  
Chemical Route ◽  
Tem Analysis ◽  
X Ray ◽  
Profile Fitting ◽  
Transmission Electron ◽  
Wide Range ◽  
Long Range Interactions ◽  
Mn3o4 Nanoparticles

AbstractA novel environmental friendly, room temperature route using an ionic liquid 1-n-butyl-3-methylimidazolium hydroxide ([BMIM]OH) for the synthesis of Mn3O4 nanoparticles is presented. The product was characterized using Fourier transform infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. Phase purity was confirmed by XRD, and X-ray line profile fitting determined a crystallite size of 42 ± 11 nm. TEM analysis revealed various morphologies. EPR measurements have indicated the existence of long-range interactions, due to the wide range of particle sizes and morphologies observed.

Production of functional platelets by differentiated embryonic stem (ES) cells in vitro

Blood ◽  
2003 ◽  
Vol 102 (12) ◽  
pp. 4044-4051 ◽  
Author(s):  
Tetsuro-Takahiro Fujimoto ◽  
Satoshi Kohata ◽  
Hidenori Suzuki ◽  
Hiroshi Miyazaki ◽  
Kingo Fujimura
Keyword(s):  
Stromal Cells ◽  
Culture Medium ◽  
Es Cells ◽  
Blood Platelets ◽  
Embryonic Stem ◽  
Clinical Applications ◽  
Platelet Production ◽  
Transmission Electron ◽  
Second Wave

Abstract Megakaryocytes and functional platelets were generated in vitro from murine embryonic stem (ES) cells with the use of a coculture system with stromal cells. Two morphologically distinctive megakaryocytes were observed sequentially. Small megakaryocytes rapidly produced proplatelets on day 8 of the differentiation, and large hyperploid megakaryocytes developed after day 12, suggesting primitive and definitive megakaryopoiesis. Two waves of platelet production were consistently observed in the culture medium. A larger number of platelets was produced in the second wave; 104 ES cells produced up to 108 platelets. By transmission electron microscopy, platelets from the first wave were relatively rounder with a limited number of granules, but platelets from the second wave were discoid shaped with well-developed granules that were indistinguishable from peripheral blood platelets. ES-derived platelets were functional since they bound fibrinogen, formed aggregates, expressed P-selectin upon stimulation, and fully spread on immobilized fibrinogen. These results show the potential utility of ES-derived platelets for clinical applications. Furthermore, production of gene-transferred platelets was achieved by differentiating ES cells that were transfected with genes of interest. Overexpression of the cytoplasmic domain of integrin β3 in the ES-derived platelets prevented the activation of αIIbβ3, demonstrating that this system will facilitate functional platelet studies. (Blood. 2003;102:4044-4051)

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

A High Resolution Study of Alumina Supported Iridium Catalysts

1980 ◽  
Vol 38 ◽  
pp. 202-203
Author(s):  
C. Stoeckert ◽  
B. Etherton ◽  
M. Beer ◽  
J. Gryder
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Metal Particles ◽  
Optical Transfer Function ◽  
Particle Sizes ◽  
Iridium Catalysts ◽  
Transmission Electron ◽  
Optical Transfer ◽  
Conventional Transmission Electron Microscope ◽  
Resolution Study

The interpretation of the activity of catalysts requires information about the sizes of the metal particles, since this has implications for the number of surface atoms available for reaction. To determine the particle dimensions we used a high resolution STEM1. Such an instrument with its simple optical transfer function is far more suitable than a conventional transmission electron microscope for the establishment of particle sizes. We report here our study on the size and number distribution of Ir particles supported on Al2O3 and also examine simple geometric models for the shape of Ir particles.

Role of Cardiac MRI in Detecting Familial Hypertrophic Cardiomyopathy: Review

2016 ◽  
Vol 1 (1) ◽  
pp. 4
Author(s):  
Marymol Koshy ◽  
Bushra Johari ◽  
Mohd Farhan Hamdan ◽  
Mohammad Hanafiah
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Magnetic Resonance ◽  
Genetic Disorder ◽  
Familial Hypertrophic Cardiomyopathy ◽  
Non Invasive ◽  
Wide Range ◽  
Proper Diagnosis ◽  
Magnetic Resonance Imaging Mri ◽  
Potential Use

Hypertrophic cardiomyopathy (HCM) is a global disease affecting people of various ethnic origins and both genders. HCM is a genetic disorder with a wide range of symptoms, including the catastrophic presentation of sudden cardiac death. Proper diagnosis and treatment of this disorder can relieve symptoms and prolong life. Non-invasive imaging is essential in diagnosing HCM. We present a review to deliberate the potential use of cardiac magnetic resonance (CMR) imaging in HCM assessment and also identify the risk factors entailed with risk stratification of HCM based on Magnetic Resonance Imaging (MRI).

scholarly journals Aging of Bone Marrow Mesenchymal Stromal Cells: Hematopoiesis Disturbances and Potential Role in the Development of Hematologic Cancers

Cancers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 68
Author(s):  
Fulvio Massaro ◽  
Florent Corrillon ◽  
Basile Stamatopoulos ◽  
Nathalie Meuleman ◽  
Laurence Lagneaux ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Tumor Progression ◽  
Cancer Progression ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Cell Communication ◽  
Bone Marrow Niche ◽  
Hematopoietic Stem ◽  
Wide Range ◽  
Major Player

Aging of bone marrow is a complex process that is involved in the development of many diseases, including hematologic cancers. The results obtained in this field of research, year after year, underline the important role of cross-talk between hematopoietic stem cells and their close environment. In bone marrow, mesenchymal stromal cells (MSCs) are a major player in cell-to-cell communication, presenting a wide range of functionalities, sometimes opposite, depending on the environmental conditions. Although these cells are actively studied for their therapeutic properties, their role in tumor progression remains unclear. One of the reasons for this is that the aging of MSCs has a direct impact on their behavior and on hematopoiesis. In addition, tumor progression is accompanied by dynamic remodeling of the bone marrow niche that may interfere with MSC functions. The present review presents the main features of MSC senescence in bone marrow and their implications in hematologic cancer progression.

Effects of Atovaquone on the Ultrastructural Morphology of Pneumocystis Carinii

1997 ◽  
Vol 3 (S2) ◽  
pp. 81-82
Author(s):  
M.P. Goheen ◽  
M.S. Bartlett ◽  
M.M. Shaw ◽  
S.R. Meshnick ◽  
J.W. Smith
Keyword(s):  
Adverse Reactions ◽  
Pneumocystis Carinii ◽  
Spinner Flask ◽  
Short Term ◽  
Human Embryonic Lung ◽  
Transmission Electron ◽  
Significant Incidence ◽  
Wide Range ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome

Pneumocystis carinii pneumonia (PCP) occurs at some time in most patients with acquired immunodeficiency syndrome (AIDS). Trimethoprim/sulfamethoxazole or pentamidine isothionate are the traditional modes of therapy for treatment and prophylaxis of PCP. Unfortunately these drugs are associated with a significant incidence of adverse side effects particularly in patients with AIDS. Toxicity and a growing concern that P. carinii strains are becoming resistant to these compounds is providing the impetus for the search for additional drugs to combat P. carinii. Atovaquone, developed as an antimalarial agent, has activity against a wide range of other organisms, including Toxoplasma sp. and P. carinii, with a lower incidence of adverse reactions during clinical trials. Atovaquone inhibits mitochondrial respiration in P. falciparum and P. carinii. In this study transmission electron microscopy (TEM) was used to observe the effects of atovaquone on P. carinii organisms in short term spinner flask culture.Spinner flask cultures of human embryonic lung cells were inoculated with P. carinii from infected rat lung.

Interfaces in Structural Ceramics

MRS Bulletin ◽  
1990 ◽  
Vol 15 (10) ◽  
pp. 51-59 ◽  
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Structural Ceramics ◽  
Interface Engineering ◽  
Micro Structure ◽  
Complete Understanding ◽  
Intimate Contact ◽  
Transmission Electron ◽  
Processed Material ◽  
Wide Range ◽  
Alternative Materials ◽  
The Relationship

Structural ceramics are necessarily polycrystalline and their usefulness is largely determined by the interfaces between the grains. The relationship between the structure and chemistry of different interfaces and the micro-structure can be illustrated by reviewing studies of interfaces in a wide range of materials including such classical ceramics as Al2O3, the current “hightech” polyphase ceramics exemplified by ZrO2-toughened Al2O3, and the composite materials of the future. Using transmission electron microscopy is essential for a complete understanding, but limitations to its use must be recognized. Only by understanding the factors that control the behavior of these interfaces will it become possible to further extend the application of interface engineering.Structural ceramics are a group of materials that can be used for applications requiring their strength to persist at high temperatures or in conditions that would be particularly corrosive to alternative materials, which are usually metallic. Strength and strength-related properties such as toughness depend largely on the microstructural features of the processed material.The microstructure is defined by the morphology and size of the grains and the interfaces between these grains. If the grains are in intimate contact, then the interface is a grain boundary of the type familiar from studies of metals.

Sign in / Sign up

Export Citation Format

Share Document