scholarly journals Morphological, ultrastructural and brightness quantitative characteristics of Helicobacter pylori electronic microscopic images

2021 ◽  
pp. 73-77
Author(s):  
V. G. Zhukhovitsky ◽  
S. O. Navolnev ◽  
N. V. Shevlyagina
Keyword(s):  
Electron Microscopy ◽  
Helicobacter Pylori ◽  
Quantitative Characteristic ◽  
Visual Assessment ◽  
Structural Features ◽  
Bacterial Cells ◽  
Transmission Electron ◽  
Quantitative Characteristics ◽  
Computer Vision Technology ◽  
Reference Strains

Using an original computer program, a quantitative characteristic of the structural features of the cultures of two reference strains of Helicobacter pylori, identified by transmission electron microscopy, was performed. The results obtained made it possible to establish morphological, ultrastructural and brightness differences between individual bacterial cells of the studied strains. The proposed program, compiled in accordance with the requirements of computer vision technology, makes it possible to detect differences in the structure of bacterial cells that are not detected by visual assessment, and also opens up the possibility of studying the phenotypic heterogeneity of isogenic populations of Helicobacter pylori and its pathogenic significance.

scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

Transmission electron microscopy studying of structural features of NiTi B2 phase formed under pulsed electron-beam impact

2015 ◽  
Author(s):  
Ludmila L. Meisner ◽  
Alexey A. Neiman ◽  
Alexander I. Lotkov ◽  
Nikolai N. Koval ◽  
Viktor O. Semin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Structural Features ◽  
Pulsed Electron Beam ◽  
Transmission Electron ◽  
B2 Phase

scholarly journals Correlation between structure and mass distribution of the nuclear pore complex and of distinct pore complex components.

1990 ◽  
Vol 110 (4) ◽  
pp. 883-894 ◽  
Author(s):  
R Reichelt ◽  
A Holzenburg ◽  
E L Buhle ◽  
M Jarnik ◽  
A Engel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nuclear Envelope ◽  
Three Dimensional ◽  
Structural Features ◽  
Nuclear Pore ◽  
Xenopus Laevis Oocyte ◽  
Three Dimensional Model ◽  
Transmission Electron ◽  
Freeze Dried

Nuclear pore complexes (NPCs) prepared from Xenopus laevis oocyte nuclear envelopes were studied in "intact" form (i.e., unexposed to detergent) and after detergent treatment by a combination of conventional transmission electron microscopy (CTEM) and quantitative scanning transmission electron microscopy (STEM). In correlation-averaged CTEM pictures of negatively stained intact NPCs and of distinct NPC components (i.e., "rings," "spoke" complexes, and "plug-spoke" complexes), several fine structural features arranged with octagonal symmetry about a central axis could reproducibly be identified. STEM micrographs of unstained/freeze-dried intact NPCs as well as of their components yielded comparable but less distinct features. Mass determination by STEM revealed the following molecular masses: intact NPC with plug, 124 +/- 11 MD; intact NPC without plug, 112 +/- 11 MD; heavy ring, 32 +/- 5 MD; light ring, 21 +/- 4 MD; plug-spoke complex, 66 +/- 8 MD; and spoke complex, 52 +/- 3 MD. Based on these combined CTEM and STEM data, a three-dimensional model of the NPC exhibiting eightfold centrosymmetry about an axis perpendicular to the plane of the nuclear envelope but asymmetric along this axis is proposed. This structural polarity of the NPC across the nuclear envelope is in accord with its well-documented functional polarity facilitating mediated nucleocytoplasmic exchange of molecules and particles.

High Resolution Imaging of As-Grown Sapphire Surfaces

1985 ◽  
Vol 62 ◽  
Author(s):  
Tung Hsu ◽  
S. R. Nutt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Features ◽  
High Resolution Imaging ◽  
Sapphire Surface ◽  
Surface Steps ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Resolution Imaging ◽  
Surface Facets

ABSTRACTSurfaces of commercially grown edge-defined film-fed growth sapphire (EFG α-Al2O3) were studied in the electron microscope using both reflection electron microscopy (REM) and conventional transmission electron microscopy (TEM). The as-grown sapphire surface, ostensibly {1120}, was characterized by “rooftop” structures which were often locally periodic. These rooftop structures consisted of alternating {1120} facets and additional facets inclined a few degrees. The crystallography of the surface facets was analyzed using REM imaging of bulk specimens, and trace analysis of back-thinned plan section TEM specimens. Surface roughness was measured by stylus profilometry. and these measurements were compared to the electron microscopy observations. Fine structural features parallel to <0110> directions were also observed in both REM and TEM experiments, and these were attributed to surface steps of atomic scales.

Microstructural characteristics and photoluminescence performance of nanograined thermally treated CeO2-TiO2 xerogels

2007 ◽  
Vol 22 (5) ◽  
pp. 1182-1187
Author(s):  
Amita Verma ◽  
A.K. Srivastava ◽  
N. Karar ◽  
Harish Chander ◽  
S.A. Agnihotry
Keyword(s):  
Electron Microscopy ◽  
Crystallite Size ◽  
Sol Gel ◽  
Structural Features ◽  
X Ray Diffraction ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Crystallite Sizes ◽  
Thermally Treated

Nanostructured thermally treated xerogels have been synthesized using a sol-gel process involving cerium (Ce) chloride heptahydrate and titanium (Ti) propoxide mixed in different Ce:Ti molar ratios. Structural features of the xerogels have been correlated with their photoluminescence (PL) response. The crystallite sizes in the samples lie in the nanorange. The x-ray diffraction and transmission electron microscopy results have confirmed the coexistence of CeO2 and TiO2 nanocrystallites in these xerogels. In general, a decrease in the CeO2 crystallite size and an increase in the TiO2 crystallite size are observed in the xerogels as a function of Ti content. Scanning electron microscopy results have evidenced the evolution of ordered structure in the xerogels as a function of TiO2 content. Although both of the phases (CeO2 and TiO2) have exhibited PL in ultraviolet and visible regions, the major luminescence contribution has been made by the CeO2 phase. The largest sized CeO2 crystallites in 1:1 thermally treated xerogel have led to its highest PL response. PL emission in the xerogels is assigned to their nanocrystalline nature and oxygen vacancy-related defects.

Molecular and atomic analysis of uranium complexes formed by three eco-types of Acidithiobacillus ferrooxidans

2002 ◽  
Vol 30 (4) ◽  
pp. 669-672 ◽  
Author(s):  
M. Merroun ◽  
C. Hennig ◽  
A. Rossberg ◽  
G. Geipel ◽  
T. Reich ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Acidithiobacillus Ferrooxidans ◽  
Energy Dispersive ◽  
Bacterial Cells ◽  
X Ray ◽  
Uranium Complexes ◽  
Transmission Electron ◽  
Polyphosphate Bodies ◽  
Atomic Analysis

A combination of EXAFS, transmission electron microscopy and energy-dispersive X-ray was used to conduct a molecular and atomic analysis of the uranium complexes formed by Acidithiobacillus ferrooxidans. The results demonstrate that this bacterium accumulates uranium as phosphate compounds. We suggest that at toxic levels when the uranium enters the bacterial cells, A. ferrooxidans can detoxify and efflux this metal by a process in which its polyphosphate bodies are involved.

Further observations on Calliacantha Leadbeater (Choanoflagellata), with special reference to C. simplex sp. nov. from many parts of the world

1979 ◽  
Vol 204 (1156) ◽  
pp. 287-300 ◽  
Keyword(s):  
Electron Microscopy ◽  
Type Species ◽  
Structural Features ◽  
Transmission Electron ◽  
The World ◽  
Functional Implications ◽  
Range Of Variation ◽  
A New Species ◽  
Whole Mounts

C. simplex is a new species with an unusually wide geographical range, occurring at sea temperatures as varied as 0°C under ice at Pt Barrow or – 1°C in arctic Canada, to 22°C on the equator at the Galapagos Islands. The morphology and range of variation are illustrated by means of light microscopy, transmission electron microscopy and scanning electron microscopy applied to dry whole mounts prepared in situ from freshly-gathered wild material. Among the diagnostic structural features, special interest attaches to the position of the anterior transverse costa which is located unusually far back in comparison with other members of the genus; it is also shown to be within and not outside the ring of four longitudinal costae building up the lorica chamber, although this feature can only be ascertained by scanning. The differences between this species and C. natans (type species of the genus) are shown to be greater and to involve more characters than could previously have been recog­nized, and some possible functional implications are discussed in a preliminary way.

EFFECT OF NITROGEN VARIATION ON THE SYNTHESIS OF VERTICALLY ALIGNED BAMBOO-SHAPED C–N NANOTUBES USING SUNFLOWER OIL

2011 ◽  
Vol 10 (04n05) ◽  
pp. 809-813 ◽  
Author(s):  
RAJESH KUMAR ◽  
RAM MANOHAR YADAV ◽  
KALPANA AWASTHI ◽  
R. S. TIWARI ◽  
O. N. SRIVASTAVA
Keyword(s):  
Electron Microscopy ◽  
Sunflower Oil ◽  
Nitrogen Doping ◽  
Nitrogen Concentration ◽  
Structural Features ◽  
Transmission Electron ◽  
Carbon Framework ◽  
Oil Mixtures ◽  
Vertically Aligned

To examine the role of NH3 on bundles of aligned bamboo-shaped carbon–nitrogen (C–N) nanotube were synthesized the pyrolysis of ferrocene (Fe(C5H5)2) and sunflower oil mixtures with NH3 being the source of nitrogen. The concentration of NH3 was varying in volume (vol). Optimized temperature and concentration of ferrocene were 825°C and 10 mg/ml, respectively. With the increase of nitrogen concentration the bundles are breaking in nearly equal parts. With nitrogen doping, the nanotubes have a bamboo-like structure and reveal degraded crystallinity of graphitic sheets. Nitrogen plays key role in generating equal compartments inside the carbon nanotube. The nanotubes were characterized by scanning electron microscopy and transmission electron microscopy that reveal the vertically aligned and hollow structural features of the nanotubes. FTIR shows the incorporation of N atom inside carbon framework and Raman spectrum indicates the enhancement of the defects inside C–N nanotube due to the N atom in C–N nanotube.

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