Bacteriocin plasmid pMB1 of Enterococcus faecalis: identification of the cell aggregation substance after induction by sex pheromone

1994 ◽  
Vol 40 (6) ◽  
pp. 500-503 ◽  
Author(s):  
R. Quirantes ◽  
I. Martín ◽  
E. Valdivia ◽  
A. Gálvez ◽  
M. Martínez-Bueno ◽  
...  
Keyword(s):  
Surface Layer ◽  
Electron Microscope ◽  
Sex Pheromone ◽  
Scanning Electron Microscope ◽  
Enterococcus Faecalis ◽  
Cell Aggregation ◽  
Surface Proteins ◽  
Aggregation Substance ◽  
Culture Supernatants ◽  
Scanning Electron

Strains of Enterococcus faecalis carrying the bacteriocinogenic plasmids pMB1 or pMB 1.1 exhibit a clumping response to culture supernatants of different enterococcal strains. Antibodies raised against cells induced by a homologous pheromone recognize two surface proteins of 152 and 72.5 kDa (the second one is possibly the degradation product of the first), respectively. These antigens are very similar to those found in induced cells of E. faecalis OGIRF(pAM211) as shown by the cross-reaction of the immune sera obtained in this work. We propose that the 152-kDa protein corresponds to the aggregation substance coded by plasmids pMB1 and pMB1.1. Moreover, antibodies raised against induced cells are able to block the pheromone-induced clumping response. When the cells induced to form aggregates by pheromones were examined under a scanning electron microscope they showed a surface layer of hairlike structures.Key words: pMB1 plasmid, sex pheromone, aggregation substance, Enterococcus faecalis.

Analysis of Tribological Processes in Components of Massive Roller Bearings

2015 ◽  
Vol 220-221 ◽  
pp. 319-323
Author(s):  
Wojciech Napadłek
Keyword(s):  
Surface Layer ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Contact Surface ◽  
Laboratory Tests ◽  
Fiber Optic ◽  
Bearing Steel ◽  
Roller Bearings ◽  
Special Software ◽  
Scanning Electron

The paper presents an analysis of tribological processes on the surface layer of large roller bearings parts carried out on bearing steel 100CrMn6. Laboratory tests carried out on roller bearings elements eg. the axle railway wagons exploitation around 600 thousand km. Modern optical microscopy with fiber optic transmission and special software was used; scanning electron microscope was applied to analyze surface stereometry; profilometers made an analyze of seizure of co-working tribological parts: roller – race roller bearings. In addition, the documentation of characteristic tribological processes occurring during the exploitation the bearings was completed. Seizure zones contact surface which occur under high and variable loads and friction were found.

Studies of physiologically active arthropod secretions. IV. Topography of the sex pheromone producing gland of the eastern spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae)

1970 ◽  
Vol 48 (3) ◽  
pp. 569-571 ◽  
Author(s):  
J. Weatherston ◽  
J. E. Percy
Keyword(s):  
Electron Microscope ◽  
Sex Pheromone ◽  
Scanning Electron Microscope ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Eastern Spruce Budworm ◽  
Scanning Electron

By use of the scanning electron microscope, the sex pheromone producing gland of the eastern spruce budworm, Choristoneura fumiferana (Clem.), was studied in relation to the mode of release of the pheromone.

scholarly journals A Study of Scanning Electron Microscope of Vancomycin Resistant <i>Enterococcus faecalis</i> from Clinical Isolates

2012 ◽  
Vol 02 (02) ◽  
pp. 93-97 ◽  
Author(s):  
Ajay Kumar Oli ◽  
Raju Sungar ◽  
Nagaveni Shivshetty ◽  
Rajeshwari Hosamani ◽  
Kelmani Chandrakanth Revansiddappa
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Enterococcus Faecalis ◽  
Clinical Isolates ◽  
Vancomycin Resistant ◽  
Scanning Electron

Microstructure of Hard Magnetic FeCr22Co15 Alloy Subjected to Tension Combined with Torsion at High Temperatures

2013 ◽  
Vol 203-204 ◽  
pp. 284-287 ◽  
Author(s):  
Anna Korneva ◽  
Galija Korznikova ◽  
Rishat Kashaev ◽  
Krzysztof Sztwiertnia
Keyword(s):  
Surface Layer ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Longitudinal Section ◽  
Maximum Amount ◽  
Σ Phase ◽  
Gradient Microstructure ◽  
Weak Gradient ◽  
Co Alloys ◽  
Scanning Electron

The paper presents the results of microstructure evolution studies of hard magnetic FeCr22Co15 alloy, destructed by tension and torsion at 800 and 850°C. The temperatures and deformation rates corresponded to the condition of superplasticity of Fe-Cr-Co alloys. Observations of longitudinal section of deformed samples in scanning electron microscope showed a formation of weak gradient microstructure with highest grain refinement in the surface layer of material. Precipitation of intermetallic σ-phase was also observed, with its maximum amount in zones of the highest deformation.

Correlation between the Morphology and Permeability of Liquid Crystalline Polymer/Polyethersulphone Blends

1992 ◽  
Vol 4 (1) ◽  
pp. 3-12 ◽  
Author(s):  
S. G. James ◽  
A. M. Donald ◽  
I. S. Miles ◽  
W. A. Macdonald
Keyword(s):  
Surface Layer ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Thin Surface Layer ◽  
Dimethyl Formamide ◽  
Hydroxybenzoic Acid ◽  
Scanning Electron

Blends of polyethersulphone (PES) and a thermotropic copolyester based on hydroxynaphthoic acid and hydroxybenzoic acid residues have been examined. The permeability to oxygen of thin pressed films of a range of compositions has been studied. It is found that fairly modest additions of the liquid crystalline polymer (LCP) lead to a pronounced improvement in barer properties. This improvement is ascribed to the formation of a thin surface layer of the LCP. The existence of this LCP surface layer is supported by examination in the scanning electron microscope of dimethyl formamide etched samples: etching does not remove all the PES because it is protected from the etchant by the surface layer.

Laser Composite Surfacing of a Magnesium Alloy with TiO2 Nanoparticles

2012 ◽  
Vol 549 ◽  
pp. 643-646 ◽  
Author(s):  
Min Zhang ◽  
Chang Jun Chen ◽  
Qun Xing Fei
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Electron Microscope ◽  
Magnesium Alloy ◽  
Scanning Electron Microscope ◽  
Cross Section ◽  
Composite Layer ◽  
Matrix Interface ◽  
Composite Surface ◽  
Scanning Electron

In the study, ZM5 Mg alloy was laser melted by dispersion of TiO2nanoparticles on its surface. The microstructure of the composite surfaced layer (both the top surface and the cross section) was characterized by optical and scanning electron microscope. A detailed analysis of the composition of the composite layer was carried out by energy dispersive spectroscopy. The microhardness of the composite layer was measured and the wear of the composite surfaced ZM5 was studied. Experimental results showed that composite surface layer consists of TiO2particles in grain refined ZM5 matrix, but the nanoparticles was agglomerated. And there was degradation of TiO2particles or interfacial reaction at the particle-matrix interface. Microhardness and wear resistance of the composite surfaced zone was improved compared to ZM5 substrate.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

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