scholarly journals Fréederisksz Transitions in 6CB Based Ferronematics—Effect of Magnetic Nanoparticles Size and Concentration

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3096
Author(s):  
Katarína Zakutanská ◽  
Danil Petrov ◽  
Peter Kopčanský ◽  
Dorota Węgłowska ◽  
Natália Tomašovičová
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Magnetic Fields ◽  
Volume Concentration ◽  
Magnetization Vector ◽  
Oxide Nanoparticles ◽  
Capacitance Measurements ◽  
Electric And Magnetic Fields

In this paper, results acquired from capacitance measurements performed on composites based on nematic liquid crystal 4-cyano-40-hexylbiphenyl (6CB) and spherical iron oxide nanoparticles of various sizes are presented. Electric and magnetic Fréedericksz transitions, as well as structural transitions in combined electric and magnetic fields, were investigated. The obtained results showed the lowering of the threshold magnetic field with an increase in the volume concentration of nanoparticles. Estimations based on results obtained from measurements suggest soft anchoring between liquid crystal director and nanoparticles magnetization vector.

scholarly journals Iron Oxide Nanoparticles for Magnetic Hyperthermia

SPIN ◽  
2019 ◽  
Vol 09 (02) ◽  
pp. 1940001 ◽  
Author(s):  
N. A. Usov
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Stochastic Equation ◽  
Sharp Decrease ◽  
Dipole Interaction ◽  
Magnetic Hyperthermia ◽  
Alternating Magnetic Field ◽  
Oxide Nanoparticles

Assemblies of magnetic nanoparticles show a great potential for application in biomedicine, particularly, magnetic hyperthermia. However, to achieve desired therapeutic effect in magnetic hyperthermia, the assembly of nanoparticles should have a sufficiently high specific absorption rate (SAR) in alternating magnetic field of moderate amplitude and frequency. Using the Landau–Lifshitz stochastic equation, it is shown that dilute assemblies of iron oxide nanoparticles of optimal diameters are capable of providing SAR of the order of 400–600[Formula: see text]W/g in alternating magnetic field with the amplitude [Formula: see text][Formula: see text]Oe in the frequency range f = 300–500[Formula: see text]kHz. Unfortunately, in dense clusters of magnetic nanoparticles, which are often formed in a biological medium, there is a sharp decrease in SAR due to the influence of strong magneto-dipole interaction of closest nanoparticles. To overcome this difficulty, it is suggested covering the nanoparticles with nonmagnetic shells of sufficient thickness or using non-single-domain nanoparticles being in magnetization curling states.

On the thermotropic and magnetotropic phase behavior of lipid liquid crystals containing magnetic nanoparticles

Nanoscale ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 3480-3488 ◽  
Author(s):  
Marco Mendozza ◽  
Costanza Montis ◽  
Lucrezia Caselli ◽  
Marcell Wolf ◽  
Piero Baglioni ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Iron Oxide ◽  
Liquid Crystals ◽  
Magnetic Nanoparticles ◽  
Magnetic Fields ◽  
Phase Behavior ◽  
Iron Oxide Nanoparticles ◽  
Superparamagnetic Iron Oxide ◽  
Oxide Nanoparticles ◽  
Promising Strategy

The inclusion of superparamagnetic iron oxide nanoparticles (SPIONs) in lipid mesophases is a promising strategy for drug-delivery applications, combining the innate biocompatibility of lipid architectures with SPIONs’ response to external magnetic fields.

scholarly journals Electrostatically modulated magnetophoretic transport of functionalised iron-oxide nanoparticles through hydrated networks

Nanoscale ◽  
2020 ◽  
Vol 12 (19) ◽  
pp. 10550-10558 ◽  
Author(s):  
Stephen Lyons ◽  
Eoin P. Mc Kiernan ◽  
Garret Dee ◽  
Dermot F. Brougham ◽  
Aoife Morrin
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
External Magnetic Field ◽  
Field Gradient ◽  
Iron Oxide Nanoparticles ◽  
Magnetic Field Gradient ◽  
Polymer Networks ◽  
Oxide Nanoparticles

Factors that determine magnetophoretic transport of magnetic nanoparticles (MNPs) through hydrated polymer networks under the influence of an external magnetic field gradient were studied.

Exploiting shape-selected iron oxide nanoparticles for the destruction of robust bacterial biofilms – active transport of biocides via surface charge and magnetic field control

Nanoscale ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 4328-4333
Author(s):  
Rachel Nickel ◽  
Mohammad Reza Kazemian ◽  
Yaroslav Wroczynskyj ◽  
Song Liu ◽  
Johan van Lierop
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Surface Charge ◽  
Iron Oxide Nanoparticles ◽  
Active Transport ◽  
Bacterial Biofilms ◽  
Oxide Nanoparticles ◽  
Field Control

Biocide-loaded magnetic nanoparticles actively transport biocides through bacterial biofilms, with biocide loading and particle efficacy improved for non-spherical shapes such as cubes and tetrapods.

scholarly journals Magneto-mechanical destruction of cancer-associated fibroblasts using ultra-small iron oxide nanoparticles and low frequency rotating magnetic fields.

2021 ◽  
Author(s):  
Sara Lopez ◽  
Nicolas Hallali ◽  
Yoann Lalatonne ◽  
Arnaud Hillion ◽  
Joana Antunes ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Cancer Therapy ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Oxide Nanoparticles ◽  
Cancer Associated Fibroblasts ◽  
Rotating Magnetic Fields ◽  
Mechanical Destruction ◽  
Interesting Approach

The destruction of cells using the mechanical activation of magnetic nanoparticles by low-frequency magnetic fields constitutes a recent and interesting approach in cancer therapy. Here, we showed that superparamagnetic iron...

A new tool to attack biofilms: driving magnetic iron-oxide nanoparticles to disrupt the matrix

Nanoscale ◽  
2019 ◽  
Vol 11 (14) ◽  
pp. 6905-6915 ◽  
Author(s):  
Jie Li ◽  
Rachel Nickel ◽  
Jiandong Wu ◽  
Francis Lin ◽  
Johan van Lierop ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Extracellular Matrix ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Bacterial Resistance ◽  
Oxide Nanoparticles ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Dc Magnetic Field ◽  
Planktonic Bacteria ◽  
The Matrix

Removing robust MRSA biofilms using magnetic nanoparticles (MNPs) under AC and DC magnetic field is demonstrated. Despite being non-toxic to planktonic bacteria, MNPs can bring damage to the extracellular matrix of biofilms and remove them from surfaces without inducing bacterial resistance.

scholarly journals Electric and Magnetic Field Effects in p-Methoxy Benzylidene p′-n-Butylaniline

1976 ◽  
Vol 31 (3-4) ◽  
pp. 283-287 ◽  
Author(s):  
N. V. S. Rao ◽  
P. R. Kishore ◽  
T. F. S. Raj ◽  
M. N. Avadhanlu ◽  
C. R. K. Murty
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Liquid Crystal ◽  
Magnetic Fields ◽  
Nematic Liquid Crystal ◽  
Nematic Phase ◽  
Relative Effectiveness ◽  
Magnetic Field Effects ◽  
Electric And Magnetic Fields ◽  
Electric And Magnetic Field

Molecular alignment in the nematic phase of p-methoxy benzylidene p′-n-butylaniline (MBBA) in the presence of electric and magnetic fields is investigated. The relative effectiveness of electric and magentic fields on the nematic liquid crystal MBBA is discussed. In the dielectric regime it is found that the threshold fields for chevron formation are considerably different from the threshold fields for inducing changes in the dielectric constant.

Evaluation of Surface-modified Superparamagnetic Iron Oxide Nanoparticles to Optimize Bacterial Immobilization for Bio-separation with the Least Inhibitory Effect on Microorganism Activity

2020 ◽  
Vol 10 (2) ◽  
pp. 166-174
Author(s):  
Mehdi Khoshneviszadeh ◽  
Sarah Zargarnezhad ◽  
Younes Ghasemi ◽  
Ahmad Gholami
Keyword(s):  
Iron Oxide ◽  
Amino Acid ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Surface Coating ◽  
Superparamagnetic Iron Oxide ◽  
Superparamagnetic Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Surface Charges ◽  
Surface Modified

Background: Magnetic cell immobilization has been introduced as a novel, facile and highly efficient approach for cell separation. A stable attachment between bacterial cell wall with superparamagnetic iron oxide nanoparticles (SPIONs) would enable the microorganisms to be affected by an outer magnetic field. At high concentrations, SPIONs produce reactive oxygen species in cytoplasm, which induce apoptosis or necrosis in microorganisms. Choosing a proper surface coating could cover the defects and increase the efficiency. Methods: In this study, asparagine, APTES, lipo-amino acid and PEG surface modified SPIONs was synthesized by co-precipitation method and characterized by FTIR, TEM, VSM, XRD, DLS techniques. Then, their protective effects against four Gram-positive and Gram-negative bacterial strains including Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were examined through microdilution broth and compared to naked SPION. Results: The evaluation of characterization results showed that functionalization of magnetic nanoparticles could change their MS value, size and surface charges. Also, the microbial analysis revealed that lipo-amino acid coated magnetic nanoparticles has the least adverse effect on microbial strain among tested SPIONs. Conclusion: This study showed lipo-amino acid could be considered as the most protective and even promotive surface coating, which is explained by its optimizing effect on cell penetration and negligible reductive effects on magnetic properties of SPIONs. lipo-amino acid coated magnetic nanoparticles could be used in microbial biotechnology and industrial microbiology.

Magnetic targeting with superparamagnetic iron oxide nanoparticles for in vivo glioma

2017 ◽  
Vol 6 (5) ◽  
pp. 449-472 ◽  
Author(s):  
Marina Fontes de Paula Aguiar ◽  
Javier Bustamante Mamani ◽  
Taylla Klei Felix ◽  
Rafael Ferreira dos Reis ◽  
Helio Rodrigues da Silva ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Superparamagnetic Iron Oxide ◽  
Superparamagnetic Iron Oxide Nanoparticles ◽  
Process Efficiency ◽  
Cochrane Library ◽  
Oxide Nanoparticles ◽  
Magnetic Targeting

AbstractThe purpose of this study was to review the use of the magnetic targeting technique, characterized by magnetic driving compounds based on superparamagnetic iron oxide nanoparticles (SPIONs), as drug delivery for a specific brain locus in gliomas. We reviewed a process mediated by the application of an external static magnetic field for targeting SPIONs in gliomas. A search of PubMed, Cochrane Library, Scopus, and Web of Science databases identified 228 studies, 23 of which were selected based on inclusion criteria and predetermined exclusion criteria. The articles were analyzed by physicochemical characteristics of SPIONs used, cell types used for tumor induction, characteristics of experimental glioma models, magnetic targeting technical parameters, and analysis method of process efficiency. The study shows the highlights and importance of magnetic targeting to optimize the magnetic targeting process as a therapeutic strategy for gliomas. Regardless of the intensity of the patterned magnetic field, the time of application of the field, and nanoparticle used (commercial or synthesized), all studies showed a vast advantage in the use of magnetic targeting, either alone or in combination with other techniques, for optimized glioma therapy. Therefore, this review elucidates the preclinical and therapeutic applications of magnetic targeting in glioma, an innovative nanobiotechnological method.

Schwinger effect in an instanton background with electric and magnetic fields via holography

2018 ◽  
Vol 33 (25) ◽  
pp. 1850144
Author(s):  
Maryam Gholizadeh Arashti ◽  
Majid Dehghani
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Production Rate ◽  
Pair Creation ◽  
Zero Temperature ◽  
Expectation Value ◽  
Background Magnetic Field ◽  
Electric And Magnetic Fields ◽  
Schwinger Effect ◽  
Horizon Limit

The Schwinger effect in the presence of instantons and background magnetic field was considered to study the dependence of critical electric field on instanton density and magnetic field using AdS/CFT conjecture. The gravity side is the near horizon limit of D3[Formula: see text]D(−[Formula: see text]1) background with electric and magnetic fields on the brane. Our approach is based on the potential analysis for particle–antiparticle pair at zero and finite temperatures, where the zero temperature case is a semi-confining theory. We find that presence of instantons suppresses the pair creation effect, similar to a background magnetic field. Then, the production rate will be obtained numerically using the expectation value of circular Wilson loop. The obtained production rate in a magnetic field is in agreement with previous results.

Sign in / Sign up

Export Citation Format

Share Document