Radiation damping strongly perturbs remote resonances in presence of homo-nuclear mixing sequences

In this work, it is experimentally shown that the weak oscillating magnetic field (known as the “radiation damping” field) caused by the inductive coupling between the transverse magnetization of nuclei and the radio frequency circuit perturbs remote resonances when homo-nuclear total correlation mixing sequences are applied. Numerical simulations are used to rationalize this effect.

Significance low oscillating magnetic field and Hall current in the nano-ferrofluid flow past a rotating stretchable disk

The present investigation involves the Hall current effects past a low oscillating stretchable rotating disk with Joule heating and the viscous dissipation impacts on a Ferro-nanofluid flow. The entropy generation analysis is carried out to study the impact of rotational viscosity by applying a low oscillating magnetic field. The model gives the continuity, momentum, temperature, magnetization, and rotational partial differential equations. These equations are transformed into the ODEs and solved by using bvp4c MATLAB. The graphical representation of arising parameters such as effective magnetization and nanoparticle concentration on thermal profile, velocity profile, and rate of disorder along with Bejan number is presented. Drag force and the heat transfer rate are given in the tabular form. It is comprehended that for increasing nanoparticle volume fraction and magnetization parameter, the radial, and tangential velocity reduce while thermal profile surges. The comparison of present results for radial and axial velocity profiles with the existing literature shows approximately the same results.

TAMI-13. MODULATION OF REDUCTIVE CARBOXYLATION FLUX OF GLUTAMINE IN GLIOBLASTOMA CELLS BY USING OSCILLATING MAGNETIC FIELD

Increased cell proliferation in glioblastoma (GBM) leads to hypoxia in the tumor microenvironment. This is a major concern in GBM patients as it promotes tumor invasion. Glutaminolysis is a hallmark of cancer cells and under hypoxic conditions glutamine metabolism proceeds through reductive carboxylation pathway. Recently, we have shown that oscillating magnetic field (OMF) produces oncolytic effects which can influence cellular metabolism. Here, we have explored the effect of OMF on glutamine metabolism in GBM cells. Patient-derived GBM cells were grown in high glucose (25 mM) DMEM supplemented with 20% fetal bovine serum (FBS), 2.0 mM glutamine and 1.0 mM pyruvate at 37 °C under humidified air and 5% CO2. Cells were divided into 2 groups (Test and Sham; n = 4 each group). When reached confluency (~2.0×106 cells/mL), cells in both groups were treated with 4.0 mM of [U-13C]glutamine in DMEM (supplemented with 20% FBS, and 1.0 mM pyruvate). The “Test” group was subjected to OMF for 3 hours, and the “Sham” group was treated similar to the “Test” group but with non-magnetic rods of the same dimensions as the magnets in the Test group. After 3 h, cells were harvested in 50% methanol analyzed by GC-MS. The 13C-isotopomer analysis showed that glutamine metabolism in GBM cells proceeds through reduction carboxylation, confirmed by the higher levels of M+5 citrate (15.42 ± 1.28 % ) than M+4 citrate (2.05 ± 0.28 %). When GBM cells were treated with OMF, a statistically significant decrease in the citrate M+5 was observed, compared to the “Sham” treated group (15.42 ± 1.28 % vs. 8.89 ± 1.30 %; p = 0.0003). This decrease in M+5 citrate upon OMF treatment clearly indicates that the OMF decreases the reductive carboxylation flux of glutamine in GBM cells which would have therapeutic value in treating GBM patients.

Simulating the Self-Assembly and Hysteresis Loops of Ferromagnetic Nanoparticles with Sticking of Ligands

The agglomeration of ferromagnetic nanoparticles in a fluid is studied using nanoparticle-level Langevin dynamics simulations. The simulations have interdigitation and bridging between ligand coatings included using a computationally-cheap, phenomenological sticking parameter c. The interactions between ligand coatings are shown in this preliminary study to be important in determining the shapes of agglomerates that form. A critical size for the sticking parameter is estimated analytically and via the simulations and indicates where particle agglomerates transition from well-ordered (c is small) to disordered (c is large) shapes. Results are also presented for the hysteresis loops (magnetization versus applied field) for these particle systems in an oscillating magnetic field appropriate for hyperthermia applications. The results show that the clumping of particles has a significant effect on their macroscopic properties, with important consequences on applications. In particular, the work done by an oscillating field on the system has a nonmonotonic dependence on c.

Nonlinear theory of macroscopic flow induced in a drop of ferrofluid

We present results of theoretical modelling of macroscopic circulating flow induced in a cloud of ferrofluid by an oscillating magnetic field. The cloud is placed in a cylindrical channel filled by a nonmagnetic liquid. The aim of this work is the development of a scientific basis for a progressive method of addressing drug delivery to thrombus clots in blood vessels with the help of the magnetically induced circulation flow. Our results show that the oscillating field can induce, inside and near the cloud, specific circulating flows with the velocity amplitude about several millimetres per second. These flows can significantly increase the rate of transport of the molecular non-magnetic impurity in the channel. This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.