scholarly journals Morphological Changes in Magnetotactic Bacteria in Presence of Magnetic Fields

2007 ◽  
Vol 3 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Megha Sharma ◽  
Mohit Naresh ◽  
Aditya Mittal
Keyword(s):  
Magnetic Fields ◽  
Morphological Changes ◽  
Magnetotactic Bacteria

Thermal fluctuations of non-motile magnetotactic bacteria in AC magnetic fields

2008 ◽  
Vol 44 (3) ◽  
pp. 223-236 ◽  
Author(s):  
K. Ērglis ◽  
L. Alberte ◽  
A. Cēbers
Keyword(s):  
Magnetic Fields ◽  
Magnetotactic Bacteria ◽  
Thermal Fluctuations

scholarly journals Inactivation of Bacteria Using Bioactive Nanoparticles and Alternating Magnetic Fields

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 342
Author(s):  
Vitalij Novickij ◽  
Ramunė Stanevičienė ◽  
Rūta Gruškienė ◽  
Kazimieras Badokas ◽  
Juliana Lukša ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Foodborne Pathogens ◽  
Morphological Changes ◽  
Foodborne Pathogen ◽  
Cellular Damage ◽  
Suitable Model ◽  
Log Reduction ◽  
Invasive Infections ◽  
Alternating Magnetic Fields ◽  
Inactivation Of Bacteria

Foodborne pathogens are frequently associated with risks and outbreaks of many diseases; therefore, food safety and processing remain a priority to control and minimize these risks. In this work, nisin-loaded magnetic nanoparticles were used and activated by alternating 10 and 125 mT (peak to peak) magnetic fields (AMFs) for biocontrol of bacteria Listeria innocua, a suitable model to study the inactivation of common foodborne pathogen L. monocytogenes. It was shown that L. innocua features high resistance to nisin-based bioactive nanoparticles, however, application of AMFs (15 and 30 min exposure) significantly potentiates the treatment resulting in considerable log reduction of viable cells. The morphological changes and the resulting cellular damage, which was induced by the synergistic treatment, was confirmed using scanning electron microscopy. The thermal effects were also estimated in the study. The results are useful for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections. The proposed methodology is a contactless alternative to the currently established pulsed-electric field-based treatment in food processing.

scholarly journals Enhancing cellular morphological changes and ablation of cancer cells via the interaction of drug co-loaded magnetic nanosystems in weak rotating magnetic fields

RSC Advances ◽  
2020 ◽  
Vol 10 (25) ◽  
pp. 14471-14481
Author(s):  
Tingting Wu ◽  
Qian Zhang ◽  
Huiping Hu ◽  
Fang Yang ◽  
Ke Li ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Cancer Cells ◽  
Morphological Changes ◽  
Rotating Magnetic Fields ◽  
Rotational Movement ◽  
Apoptotic Effect

Tetrandrine and Fe3O4 nanoparticle co-loaded PLGA nanosystems produce rotational movement and promote tetrandrine release, causing a dual apoptotic effect to tumors.

scholarly journals Imposing Local Magnetic Fields to Control Magnetotactic Bacteria Through Combining Microfabrication and Magnetism

2011 ◽  
Vol 100 (3) ◽  
pp. 514a
Author(s):  
Lina M. Gonzalez ◽  
Warren C. Ruder ◽  
SiYen Chou ◽  
Eli Zenkov ◽  
William Messner ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Magnetotactic Bacteria ◽  
Local Magnetic Fields

Sensing of Local, Highly Concentrated Magnetic Field Gradients in Magnetotactic Bacteria Induces Motility Reversal

2012 ◽  
Author(s):  
Lina M. González ◽  
Warren C. Ruder ◽  
William C. Messner ◽  
Philip R. LeDuc
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetotactic Bacteria ◽  
Chemical Gradients ◽  
Field Gradients ◽  
Magnetic Field Gradients ◽  
Direction Of Movement ◽  
Unicellular Organisms ◽  
Sense And Respond ◽  
Direction Reversal

Many motile unicellular organisms have evolved specialized behaviors for detecting and responding to chemical gradients (chemotaxis) or oxygen (aerotaxis), while magnetotactic bacteria sense magnetic fields to align their direction of movement. Herein we show that Magnetospirillum magneticum (AMB-1) have the ability to sense and respond not only to the direction of magnetic fields of naturally occurring magnitude, but also to local, highly concentrated magnetic field gradients that do not occur in their natural environment. We imposed these gradients through our system integrating Helmholtz coils and permalloy (Ni80Fe20) microstructures. The AMB-1 exhibit three distinct behaviors as they approached gradients near the microstructures—unidirectional, single direction reversal, and double direction reversal. These results indicate previously unknown capabilities of the magnetic sensing systems of AMB-1.

Dynamics of information characteristics of the gravity of patho-morphological changes at the rotating and pulse traveling magnetic fields impact on the organism

10.12737/7234 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 0-0
Author(s):  
Исаева ◽  
N. Isaeva
Keyword(s):  
Magnetic Fields ◽  
Information Entropy ◽  
System Analysis ◽  
Morphological Changes ◽  
Low Frequency ◽  
Structural Diversity ◽  
Pathological Process ◽  
Control Group ◽  
Pathological Changes ◽  
Information Characteristics

The paper presents research results of patho-morphological effects of extremely low frequency rotating magnetic fields and pulsed traveling magnetic fields on the kidneys of mammals from the perspective of in-formation theory. The study was conducted in four experimental groups and one control group, each of which consisted of 15 adult mice line S/Bl6. The following information characteristics were determined for all groups: information capacity, i.e. the maximum structural diversity of functional systems, information entropy, information organization, information relative entropy and the coefficient of relative organization of the system. Analysis of the values of information characteristics have allowed to establish that the lowest values of information entropy and maximum values of the coefficient of relative organization of the system were obtained in the groups with the most severe pathological changes. This indicates the formation of stable equilibrium as the norm, and in terms of irreversible pathological process. The results of the correlation analysis in all groups showed that the highest accuracy of prediction have regression model for relative information entropy, obtained in the control group and in group 2, in which severe pathological changes didn’t observed.

Extra sensory receptors

2019 ◽  
pp. 217-240
Author(s):  
Gordon L. Fain
Keyword(s):  
Molecular Biology ◽  
Magnetic Fields ◽  
Channel Gating ◽  
Magnetotactic Bacteria ◽  
Structure And Function ◽  
Sensory Transduction ◽  
Sensory Receptors ◽  
Sensory Modalities ◽  
Migrating Birds ◽  
And Function

“Extra sensory receptors” is the tenth chapter of the book Sensory Transduction and reviews mechanisms of sensory transduction in three additional sensory modalities: thermoreception, electroreception, and magnetoreception. It describes the physiology and molecular biology of warm and cold receptors in the mammalian skin, including the channels thought to be responsible and mechanisms of channel gating. There follows an extensive description of thermoreceptors in the pit organs of snakes which permit these animals literally to see in the dark. The section on electroreception reviews in detail the mechanism responsible for the astonishing sensitivity of the ampullary receptors of skates, as well as the structure and function of tuberous receptors, electrocytes, and electrolocation. The final section on magnetoreception describes magnetotactic bacteria as well as the evidence for magnetoreception in migrating birds, together with theories—as yet unproved—for the mechanism of animal sensitivity to magnetic fields.

scholarly journals Characterization of Bacterial Magnetotactic Behaviors by Using a Magnetospectrophotometry Assay

2009 ◽  
Vol 75 (12) ◽  
pp. 3835-3841 ◽  
Author(s):  
Christopher T. Lefèvre ◽  
Tao Song ◽  
Jean-Paul Yonnet ◽  
Long-Fei Wu
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Light Beam ◽  
Geomagnetic Field ◽  
Magnetic Particles ◽  
Magnetotactic Bacteria ◽  
Cell Alignment ◽  
The North ◽  
Field Lines ◽  
A Chain

ABSTRACT Magnetotactic bacteria have the unique capacity of synthesizing intracellular single-domain magnetic particles called magnetosomes. The magnetosomes are usually organized in a chain that allows the bacteria to align and swim along geomagnetic field lines, a behavior called magnetotaxis. Two mechanisms of magnetotaxis have been described. Axial magnetotactic cells swim in both directions along magnetic field lines. In contrast, polar magnetotactic cells swim either parallel to the geomagnetic field lines toward the North Pole (north seeking) or antiparallel toward the South Pole (south seeking). In this study, we used a magnetospectrophotometry (MSP) assay to characterize both the axial magnetotaxis of “Magnetospirillum magneticum” strain AMB-1 and the polar magnetotaxis of magneto-ovoid strain MO-1. Two pairs of Helmholtz coils were mounted onto the cuvette holder of a common laboratory spectrophotometer to generate two mutually perpendicular homogeneous magnetic fields parallel or perpendicular to the light beam. The application of magnetic fields allowed measurements of the change in light scattering resulting from cell alignment in a magnetic field or in absorbance due to bacteria swimming across the light beam. Our results showed that MSP is a powerful tool for the determination of bacterial magnetism and the analysis of alignment and swimming of magnetotactic bacteria in magnetic fields. Moreover, this assay allowed us to characterize south-seeking derivatives and non-magnetosome-bearing strains obtained from north-seeking MO-1 cultures. Our results suggest that oxygen is a determinant factor that controls magnetotactic behavior.

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