scholarly journals Cell death via remote heating of microparticles with potential applications in atherosclerosis and thrombosis therapy

2015 ◽  
Author(s):  
Angelo Gaitas ◽  
Gwangseong Kim
Keyword(s):  
Cell Death ◽  
Induction Heating ◽  
Initial Density ◽  
Spherical Particles ◽  
Maximum Temperature ◽  
Inductive Heating ◽  
Iron Particles ◽  
Heating Treatment ◽  
Potential Applications ◽  
Micrometer Size

We report a method to cause cell death by remotely heating microparticles by induction heating, this technique could be used to remove vascular deposits and thrombosis. In this preliminary work, we used micrometer size spherical (ferromagnetic) particles and (pure) iron particles to heat remotely macrophages using inductive heating. Iron particles achieved maximum temperatures of 51 ± 0.5 oC after 30 minutes of inductive heating, while spherical particles achieved a maximum temperature of 43.9 ± 0.2 oC (N=6). The therapeutic outcome was determined by monitoring cell re-growth for 2 days following inductive heating treatment. The initial density of cells in the first day prior to induction heating was 105,000 ± 20,820 cells/ml (N=3). 24 hours after induction heating this number was reduced to 6,666 ± 4,410 cells/ml for the spherical particles and 16,666 ± 9,280 cells/ml for the iron particles. The second day the cells grew to 26,667 ± 6,670 cells/ml and 30,000 ± 15,280 cells/ml respectively. Compared to cell cultures with iron and spherical particles that were not subjected to induction heating, we observed a 97% reduction in cell count for the spherical particles and a 91% reduction for the iron particles after the first 24 hours. After 48 hours we observed a 95% reduction in cell growth for both spherical and iron particles. Induction heating of microparticles was highly effective in reducing the macrophage population and preventing their growth.

scholarly journals Cell death via remote heating of microparticles with potential applications in atherosclerosis and thrombosis therapy

2015 ◽  
Author(s):  
Angelo Gaitas ◽  
Gwangseong Kim
Keyword(s):  
Cell Death ◽  
Induction Heating ◽  
Initial Density ◽  
Spherical Particles ◽  
Maximum Temperature ◽  
Inductive Heating ◽  
Iron Particles ◽  
Heating Treatment ◽  
Potential Applications ◽  
Micrometer Size

We report a method to cause cell death by remotely heating microparticles by induction heating, this technique could be used to remove vascular deposits and thrombosis. In this preliminary work, we used micrometer size spherical (ferromagnetic) particles and (pure) iron particles to heat remotely macrophages using inductive heating. Iron particles achieved maximum temperatures of 51 ± 0.5 oC after 30 minutes of inductive heating, while spherical particles achieved a maximum temperature of 43.9 ± 0.2 oC (N=6). The therapeutic outcome was determined by monitoring cell re-growth for 2 days following inductive heating treatment. The initial density of cells in the first day prior to induction heating was 105,000 ± 20,820 cells/ml (N=3). 24 hours after induction heating this number was reduced to 6,666 ± 4,410 cells/ml for the spherical particles and 16,666 ± 9,280 cells/ml for the iron particles. The second day the cells grew to 26,667 ± 6,670 cells/ml and 30,000 ± 15,280 cells/ml respectively. Compared to cell cultures with iron and spherical particles that were not subjected to induction heating, we observed a 97% reduction in cell count for the spherical particles and a 91% reduction for the iron particles after the first 24 hours. After 48 hours we observed a 95% reduction in cell growth for both spherical and iron particles. Induction heating of microparticles was highly effective in reducing the macrophage population and preventing their growth.

scholarly journals Finite-Element Simulation of Residual Stresses During the Processing of Lumped Burnable Absorber Fuel

2021 ◽  
Vol 9 ◽  
Author(s):  
Qusai Mistarihi ◽  
Ho Jin Ryu
Keyword(s):  
Finite Element ◽  
Threshold Stress ◽  
Initial Density ◽  
Interfacial Stress ◽  
Spherical Particles ◽  
Stabilized Zirconia ◽  
Interfacial Cracks ◽  
Element Simulation ◽  
Shielding Factor ◽  
Burnable Absorber

UO2–Gd2O3 fuel is mostly used as a burnable absorber fuel in the form of a homogenous mixture of Gd2O3 and UO2. More effective reactivity control can be achieved by lumping Gd2O3 within the UO2 because this enhances the spatial self-shielding factor of the burnable absorber fuel. The fabrication of lumped burnable absorber fuel containing lumped Gd2O3 spherical particles or compacts has been experimentally demonstrated using yttrium-stabilized zirconia (YSZ) as a UO2 fuel surrogate. Interfacial cracks or gaps forming under the interfacial stress that develops during the fabrication of the fuel can be eliminated by controlling the initial density of the lumped Gd2O3. In this study, this interfacial stress during the fabrication process was simulated using finite element methods. The effect of the size, shape, and initial density of the lumped Gd2O3 on the distribution and magnitude of the interfacial stress was investigated. The addition of Gd2O3 spherical particles resulted in a lower and more uniform interfacial stress distribution than the addition of cylindrical Gd2O3 compacts. The interfacial stress was increased with increasing Gd2O3 size and initial density. The calculated interfacial stress was compared with experimental results to estimate the threshold stress for crack development in a lumped burnable absorber fuel.

Thermal Characterizations of HPMC/PVA Impregnated with CNC Electrospun Nanofibers

2020 ◽  
Vol 981 ◽  
pp. 115-120
Author(s):  
Etdal Bakhiet ◽  
Siti Fazira Samsudin ◽  
Farah Hanani Zulkifli ◽  
Aizi Nor Mazila Ramli
Keyword(s):  
Hydroxypropyl Methylcellulose ◽  
Electrospun Nanofibers ◽  
Maximum Temperature ◽  
Poly Vinyl Alcohol ◽  
Electrospun Nanofiber ◽  
Random Orientation ◽  
Electrospinning Technique ◽  
Peak Intensity ◽  
Major Weight Loss ◽  
Potential Applications

Interest in the nanotechnology invention has been increased among the researcher and industries which lead to many investigations and studies to develop a product with better performance. In this research, hydroxypropyl methylcellulose (HPMC) and poly (vinyl) alcohol (PVA) nanofiber with the ratio 1:1 and the concentration of 5 wt% and 7 wt%, respectively, were successfully fabricated by using electrospinning technique. The HPMC/ PVA was then blended with the different concentration of cellulose nanocrystal (CNC) at 2 wt%, 4 wt%, 6 wt% and 8 wt%. The SEM results of HPMC/PVA/CNC nanofibers shown random orientation fibers with average diameters of 62.28 nm - 252.80 nm. The TGA results showed three major weight loss that prove the decomposotion of HPMC/PVA/CNC was occured with three maximum temperature peaks around 69 °C, 290 °C and 392 °C. As for DSC, the peak intensity of the Tg in the electrospun nanofiber are decreasing as the concentration of CNCs increased might be due to the interfering of the CNC with the crystallization of the polymer causing mobility of the amorphous regions to be higher. Therefore, the study on the thermal properties of HPMC/PVA incorporated with CNCs nanofibers could be a reference for various potential applications.

PREPARATION AND ABRASION PROPERTIES OF MAGNETO-RHEOLOGICAL FLUID OF DISPERSED SILICA-COATED IRON

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1121-1127 ◽  
Author(s):  
A. SHIBAYAMA ◽  
T. OTOMO ◽  
Y. AKAGAMI ◽  
K. SHIMADA ◽  
T. FUJITA
Keyword(s):  
Carbonyl Iron ◽  
Spherical Particles ◽  
Fluid Viscosity ◽  
Iron Particles ◽  
Mr Fluid ◽  
Abrasion Test ◽  
Silicon Oil ◽  
Mr Fluids ◽  
Transmission Oil ◽  
Magneto Rheological

In this study, a magneto-rheological fluid dispersed by silica-coated iron was developed and its properties such as fluid viscosity (shear stress or shear rate) and abrasion were investigated. The metallic iron coated by silica dispersed in magneto-rheological fluid was prepared by H 2 reducing of precipitated magnetite ( Fe 3 O 4). Then, the magneto-rheological fluid (MR fluid) for the seal was prepared with silica-coated iron or carbonyl iron (HQ type; diameter of 1.6-1.9 10-6m) and two solvent oils i.e. silicon oil (SH200cv, 10000cSt) and CVT oil (T-CVTF, automobile transmission oil). It was observed that the MR fluid viscosity of CVT oil with HQ particles is lower in every fluid condition. Furthermore, the surface roughness of polyvinyl plate after abrasion test for MR fluid with silica coated iron and CVT oil as solvent was higher compared to the other types of MR fluids. The results indicated that carbonyl iron (spherical particles) and silica-coated iron particles dispersed in silicon oil are feasible to be used where the low abrasion in mechanics is required.

scholarly journals Gold Nanoparticle-Induced Cell Death and Potential Applications in Nanomedicine

2018 ◽  
Vol 19 (3) ◽  
pp. 754 ◽  
Author(s):  
Hainan Sun ◽  
Jianbo Jia ◽  
Cuijuan Jiang ◽  
Shumei Zhai
Keyword(s):  
Cell Death ◽  
Gold Nanoparticle ◽  
Potential Applications

scholarly journals Optimal control for a phase field model of melting arising from inductive heating

2022 ◽  
Vol 7 (1) ◽  
pp. 121-142
Author(s):  
Zonghong Xiong ◽  
◽  
Wei Wei ◽  
Ying Zhou ◽  
Yue Wang ◽  
...  
Keyword(s):  
Optimal Control ◽  
Field Equation ◽  
Heat Equation ◽  
Induction Heating ◽  
Phase Field ◽  
Control Variable ◽  
Melting Process ◽  
Inductive Heating ◽  
Controlled System ◽  
Metal Melting

<abstract><p>Due to its unique performance of high efficiency, fast heating speed and low power consumption, induction heating is widely and commonly used in many applications. In this paper, we study an optimal control problem arising from a metal melting process by using a induction heating method. Metal melting phenomena can be modeled by phase field equations. The aim of optimization is to approximate a desired temperature evolution and melting process. The controlled system is obtained by coupling Maxwell's equations, heat equation and phase field equation. The control variable of the system is the external electric field on the local boundary. The existence and uniqueness of the solution of the controlled system are showed by using Galerkin's method and Leray-Schauder's fixed point theorem. By proving that the control-to-state operator $ P $ is weakly sequentially continuous and Fréchet differentiable, we establish an existence result of optimal control and derive the first-order necessary optimality conditions. This work improves the limitation of the previous control system which only contains heat equation and phase field equation.</p></abstract>

scholarly journals Two-channel time-optimal control of induction heating process with maximum temperature constraint

2020 ◽  
Vol 28 (2) ◽  
pp. 41-58
Author(s):  
Natalya A. Il`ina
Keyword(s):  
Optimal Control ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Induction Heating ◽  
Time Optimal Control ◽  
Maximum Temperature ◽  
Heating Process ◽  
Problem Of Time ◽  
Control Actions ◽  
Time Optimal

The formulation and method of solution of the problem of time-optimal control of induction heating process of an unlimited plate with two control actions on the value of internal heat sources with technological constraint in relation to a one-dimensional model of the temperature field are proposed. The problem is solved under the conditions of a given accuracy of uniform approximation of the final temperature distribution over the thickness of the plate to the required. The method of finite integral transformations is used to search for the input-output characteristics of an object with distributed parameters with two control actions. The preliminary parameterization of control actions based on analytical optimality conditions in the form of the Pontryagin maximum principle is used. At the next stage reduction is performed to the problem of semi-infinite optimization, the solution of which is found using the alternance method. The alternance properties of the final resulting temperature state at the end of the optimal process lead to a basic system of relations, which, if there is additional information about the shape of the temperature distribution curve, is reduced to a system of equations that can be solved. An example of solving the problem of time-optimal control of temperature field of an unlimited plate with two offices is carried out in two stages. At first stage the case of induction heating without maximum temperature constraints is considered, at the second stage is carried out on the basis of the results of the first stage to obtain the solution subject to the limitation on the maximum temperature of the heated billet.

scholarly journals OPTIMAL INDUCTOR DESIGN FOR SURFACE HARDENING OF CYLINDRICAL BILLETS BASED ON NUMERICAL TWO-DIMENSIONAL MODEL

2019 ◽  
pp. 40-50
Author(s):  
Yuliya Edgarovna Pleshivtseva ◽  
Anton Valerjevich Popov ◽  
Mariya Aleksandrovna Popova ◽  
Maxim Yurjevich Derevyanov
Keyword(s):  
Optimal Design ◽  
Induction Heating ◽  
Operation Mode ◽  
Heating Time ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Design Parameters ◽  
Distributed Parameters ◽  
Heating Installation ◽  
And Control

Contemporary industrial production widely uses induction heating prior to the plastic deformation and heat treatment operations due to the benefits it provides in comparison with other types of heating technologies. In order to increase the efficiency of induction heating units and develop their operation mode, the research should be directed towards new design solutions in optimizing constructive parameters of inductors and control algorithms of heating processes. The main goal of the research is developing the best inductor design, which provides maximum temperature uniformity in the surface layer of the billet at the end of heating time. There has been formulated the problem of the inductor unit optimal design with respect to steel cylindrical billets, which can be solved by using the alternance method of parametric optimization of the systems with distributed parameters. Design parameters of the induction heating installation that include the geometry features and the current of power supply are considered as optimized parameters. Software package FLUX was used for developing 2D numerical model of interrelated magnetic and temperature fields in the process of induction heating to describe the system ‘induction heater - billet’. The results of numeric solution of the problem of optimal design have been analyzed.

scholarly journals Characterization of Cell Lysis in Pseudomonas putida Induced upon Expression of Heterologous Killing Genes

1998 ◽  
Vol 64 (12) ◽  
pp. 4904-4911 ◽  
Author(s):  
M. Carmen Ronchel ◽  
Lázaro Molina ◽  
Angela Witte ◽  
Werner Lutbiz ◽  
Søren Molin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Death ◽  
Pseudomonas Putida ◽  
Membrane Permeability ◽  
Cell Lysis ◽  
Physiological Effects ◽  
Extracellular Medium ◽  
Biological Containment ◽  
Potential Applications

ABSTRACT Active biological containment systems are based on the controlled expression of killing genes. These systems are of interest for thePseudomonadaceae because of the potential applications of these microbes as bioremediation agents and biopesticides. The physiological effects that lead to cell death upon the induction of expression of two different heterologous killing genes in nonpathogenicPseudomonas putida KT2440 derivatives have been analyzed.P. putida CMC4 and CMC12 carry in their chromosomes a fusion of the PA1-04/03 promoter to the Escherichia coli gef gene and the φX174 lysis gene E, respectively. Expression of the killing genes is controlled by the LacI protein, whose expression is initiated from the XylS-dependent Pm promoter. Under induced conditions, killing of P. putidaCMC12 cells mediated by φX174 lysis protein E was faster than that observed for P. putida CMC4, for which the Gef protein was the killing agent. In both cases, cell death occurred as a result of impaired respiration, altered membrane permeability, and the release of some cytoplasmic contents to the extracellular medium.

scholarly journals Bifunctional Carbon Dots—Magnetic and Fluorescent Hybrid Nanoparticles for Diagnostic Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Ilana Perelshtein ◽  
Nina Perkas ◽  
Shai Rahimipour ◽  
Aharon Gedanken
Keyword(s):  
Hybrid Material ◽  
Magnetic Particles ◽  
Ultrasound Irradiation ◽  
Hybrid Nanoparticles ◽  
Diagnostic Tools ◽  
Photoluminescence Properties ◽  
Iron Particles ◽  
Simple Detection ◽  
Potential Applications ◽  
Diagnostic Applications

There is a huge demand for materials capable of simple detection or separation after conjugation with specific biologic substances when applied as a diagnostic tools. Taking into account the photoluminescence properties of C-dots and the highly magnetic properties of Fe(0), a new hybrid composite of these components was synthesized via ultrasound irradiation. The material was fully characterized by various physicochemical techniques. The main goal of the current study was to obtain a highly magnetic and intense fluorescent hybrid material. The goal was achieved. In addition, magnetic particles tended to agglomerate. The new hybrid can be suspended in ethanol, which is an additional feature of the current research. The dispersion of the hybrid nanoparticles in ethanol was achieved by utilizing the interaction of iron particles with C-dots which were decorated with functional groups on their surface. The newly formed hybrid material has potential applications in diagnostic by conjugating with specific antibodies or with any other biologic compounds. Such application may be useful in detection of various diseases such as: cancer, tuberculosis, etc.

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