Low Intensity Therapeutic Ultrasound Effect on Nano-Particle Motion in a Viscous Medium

2008 ◽  
Author(s):  
Natalya Mizrahi ◽  
Daphne Weihs ◽  
Eitan Kimmel
Keyword(s):  
Particle Motion ◽  
Biological Effects ◽  
Viscoelastic Model ◽  
Therapeutic Ultrasound ◽  
Methyl Cellulose ◽  
Model System ◽  
Nano Particles ◽  
Shear Stresses ◽  
Low Intensity ◽  
Intracellular Organelles

While low intensity therapeutic ultrasound irradiation (LITUS) has been shown to have biological effects on tissue and cells, the physical mechanism leading to those effects has yet to be characterized. As a model system to study effects of LITUS on intracellular organelles, we monitor the dynamics of nanoparticles suspended in a viscoelastic medium, before and during LITUS treatment. Particle motion dynamics can indicate: i) forces acting on similarly-sized intracellular organelles; ii) streaming flow induced in cells and in cavities in contact with cells; and iii) instantaneous (under LITUS) changes in the mechanical properties of viscoelastic media in general and cells in particular. Forces and flow can result in shear stresses that act on the cell membrane of, e.g., endothelial cells in blood vessels and may cause biophysical responses. Particle motion in a high-viscosity, viscoelastic model solution, methyl cellulose, was used as an indicator for sample response under LITUS. The ultrasound-induced motion of nano-particles was quantified by real-time particle-tracking microrheology methods. Particle motion without LITUS irradiation demonstrated diffusive-like behavior with no underlying convection. In contrast, during LITUS irradiation convective motion with a particle-velocity profile parabolic in time was observed. Particles were accelerated after initiation of LITUS irradiation, then a transient phase of constant velocity was observed, and finally the speed was reduced. Altogether the results of the study indicate that LITUS may apply considerable direct forces on suspended particles, a model system for cellular organelles. More studying will help elucidate the mechanisms of LITUS effects. Extending this approach to cells in vitro and evaluating their response can promote the use of ultrasound as a therapeutic tool for delicate manipulation of cells in vivo in a controlled, targeted, and non-invasive way. At the same time, one can define the safety limits and optimal range for therapeutic and diagnostic ultrasound by indicating the threshold for irreversible intracellular changes.

Biological effects of low-intensity radiofrequency fields and risk assessment for biota

2020 ◽  
Vol 60 (9) ◽  
pp. 592-596
Author(s):  
Elena I. Sarapultseva ◽  
Darya V. Uskalova ◽  
Ksenya V. Ustenko
Keyword(s):  
Radio Frequency ◽  
Electromagnetic Radiation ◽  
Electromagnetic Fields ◽  
Negative Impact ◽  
Biological Effects ◽  
High Sensitivity ◽  
Communication Technologies ◽  
Natural Ecosystems ◽  
Low Intensity ◽  
Different Levels

Despite the fact that there are still conflicting opinions about the damage caused by modern wireless communication technologies, most scientists report on the negative biological effects of low-intensity radio frequency electromagnetic radiation at different levels of the organization of live nature. There is no doubt that there is a need not only for a sanitary and hygienic assessment of man-made electromagnetic effects on humans, but also for an environmental assessment for biota. The purpose of the study was to assess the potential environmental risk of electromagnetic impact in the centimeter range on natural ecosystems. The initial data were the authors' own results in the field of radiobiology of non-ionizing radiation, as well as published of other researchers. The article analyzes the biological effects of radio frequency electromagnetic fields detected in organisms of different systematic groups and levels of organization. The data on the non-thermal biological effects of electromagnetic fields indicate a high sensitivity of different species to this factor. The analyzed research results emphasize the need to take into account the features of non-thermal effects of electromagnetic radiation on biota, since these radiations can have a negative impact on different hierarchical levels in natural ecosystems.

A study on biological effects of low-intensity millimeter waves

2002 ◽  
Vol 30 (4) ◽  
pp. 1489-1496 ◽  
Author(s):  
Guofen Yu ◽  
E.A. Coln ◽  
K.H. Schoenbach ◽  
M. Gellerman ◽  
P. Fox ◽  
...  
Keyword(s):  
Millimeter Waves ◽  
Biological Effects ◽  
Low Intensity

Nano Particles and Their Mode of Action in Environment

2018 ◽  
pp. 212-219
Author(s):  
Rakesh Bhatt ◽  
Sandeep Gupta
Keyword(s):  
European Union ◽  
Human Activities ◽  
Mode Of Action ◽  
Biological Effects ◽  
Inorganic Compounds ◽  
Consumer Products ◽  
Nano Particles ◽  
Daily Activities ◽  
The World ◽  
Innovative Materials

Nano particles are particles that exist on a nanometer scale. Nanoparticles exist in our surrounding either naturally or created by human activities. As per Commission of European Union (2011), a nano-object needs only one of its characteristic dimensions to be in the range of 1-100nm to be classed as a nanoparticle even if its other dimensions are outside that range. Nanoparticles have revolutionized the world through the introduction of a unique class of material and consumer products in many fields due to production of innovative materials and devices. Despite their unique benefits and utility in daily activities, this could result in undesirable changes in the environment and affect the workplace. Carbon-based nanoparticles, oxides of metals, and natural inorganic compounds can have biological effects on the environment and human health. This chapter deals with the nanoparticles and their mode of action in the environment.

Insulin and insulinlike growth factor receptors and responses in cultured human muscle cells

1986 ◽  
Vol 251 (5) ◽  
pp. E611-E615 ◽  
Author(s):  
M. Shimizu ◽  
C. Webster ◽  
D. O. Morgan ◽  
H. M. Blau ◽  
R. A. Roth
Keyword(s):  
Insulin Receptor ◽  
Biological Effects ◽  
Muscle Cells ◽  
Model System ◽  
Human Muscle ◽  
Acid Analogue ◽  
Igf I ◽  
Specific Receptors ◽  
Human Muscle Cells ◽  
Biological Actions

Specific receptors for insulinlike growth factors I and II (IGF-I and IGF-II) were found on cultured human myoblasts and myotubes. In contrast, myotubes but not myoblasts specifically bound insulin and were stimulated by nanomolar concentrations of insulin to take up deoxyglucose. In addition, in myoblasts, physiological concentrations of IGF-I and -II and, to a lesser extent, insulin stimulated two- to threefold the uptake of the nonmetabolizable amino acid analogue methylaminoisobutyric acid (MAIB). In myotubes, uptake of MAIB was stimulated preferentially by IGF-I. Monoclonal antibodies that preferentially recognize either the insulin receptor or the IGF-I receptor were utilized to examine which receptors mediated the biological effects of these hormones. The effects of insulin on both myoblasts and myotubes appeared to be mediated in part by the insulin receptor and in part by the IGF-I receptor. In myotubes, the effects of IGF-I and -II both appeared to be mediated through the IGF-I receptor. In myoblasts, the effects of the two IGFs appeared to be in part mediated by the IGF-I receptor and in part mediated by either the IGF-II receptor or another type of IGF-I receptor. The present results suggest that cultured human muscle cells provide a useful model system in which to study the biological actions of insulin and the IGFs.

scholarly journals Novel Targeted Anti-Tumor Nanoparticles Developed from Folic Acid-Modified 2-Deoxyglucose

2019 ◽  
Vol 20 (3) ◽  
pp. 697 ◽  
Author(s):  
Shaoming Jin ◽  
Zhongyao Du ◽  
Huiyuan Guo ◽  
Hao Zhang ◽  
Fazheng Ren ◽  
...  
Keyword(s):  
Folic Acid ◽  
Cell Viability ◽  
Cancer Cells ◽  
Water Solubility ◽  
Computational Study ◽  
Biological Effects ◽  
Docking Simulation ◽  
Nano Particles ◽  
Cycle Arrest ◽  
Nano Drug Delivery

The glucose analog, 2-deoxyglucose (2-DG), specifically inhibits glycolysis of cancer cells and interferes with the growth of cancer cells. However, the excellent water solubility of 2-DG makes it difficult to be concentrated in tumor cells. In this study, a targeted nano-pharmacosome was developed with folic acid-modified 2-DG (FA-2-DG) by using amino ethanol as a cleavable linker. FA-2-DG was able to self-assemble, forming nano-particles with diameters of 10–30 nm. The biological effects were evaluated with cell viability assays and flow cytometry analysis. Compared with a physical mixture of folic acid and 2-DG, FA-2-DG clearly reduced cell viability and resulted in cell cycle arrest. A computational study involving docking simulation suggested that FA-2-DG can dock into the same receptor as folic acid, thus confirming that the structural modification did not affect the targeting performance. The results indicated that the nano-pharmacosome consisting of FA-2-DG can be used for targeting in a nano-drug delivery system.

scholarly journals Effect of a modified nano clay and nano graphene on rheology, stability of water-in-oil emulsion, and filtration control ability of oil-based drilling fluids: a comparative experimental approach

2020 ◽  
Vol 75 ◽  
pp. 40
Author(s):  
Vahid Nooripoor ◽  
Abdolnabi Hashemi
Keyword(s):  
Base Fluid ◽  
Emulsion Stability ◽  
Nano Particles ◽  
Model Parameters ◽  
Drilling Fluids ◽  
Shear Stresses ◽  
Oil Emulsion ◽  
Nano Clay ◽  
Nano Graphene ◽  
Water In Oil Emulsion

During the past decade, researchers have used different Nano-Particles (NPs) due to their unique characteristics for improving formulation of Oil-Based Drilling Fluids (OBDFs). This study is the first research that investigates the effect of a Modified Nano Clay (MNC), namely CLOISITE 5 and non-functionalized Nano Graphene (NG) on rheology, electrical/emulsion stability, and filtration control ability, as the main properties of OBDFs. Initially, five concentrations of both NPs (0.25, 0.5, 1, 1.5, and 2 wt%) were added separately into an NP-free OBDF (the base fluid). Then, rheological properties and electrical stability of all prepared fluids were measured at three 90, 140, and 180 °F temperatures. Moreover, filtration test was carried out under 500 psi (3447 kPa) differential pressure and exposed to 300 °F temperature for all fluids. Since experimentally measured shear stresses followed well both Herschel Bulkley (shear-thinning) and Bingham Plastic models, effects of temperature and the NPs concentration on both model parameters are investigated more deeply in the paper. Activation energies calculated from Arrhenius model showed that MNC is more effective than NG on reducing the dependency of apparent and plastic viscosities of the base fluid on temperature. MNC, due to its amphiphilic structure, significantly stabilizes water-in-oil emulsion at all temperatures and concentrations, but NG with high electrical conductivity reduces the emulsion stability. The nanofluids containing 0.5 wt% MNC and 0.25 wt% NG which have respectively 32.6% and 43.5% fewer filtrate volumes than the base fluid, were considered as the optimal nanofluids from controlling filtration into formation aspect. Finally, MNC is applicable to enhance the formulation of the OBDF through supporting its commercial viscosifier, emulsifiers, and fluid loss control agent, but the negative effect of NG on emulsion stability limits its application.

VALIDATION AND USE OF SPILL IMPACT MODELING FOR IMPACT ASSESSMENT

1997 ◽  
Vol 1997 (1) ◽  
pp. 829-834 ◽  
Author(s):  
Deborah P. French ◽  
Henry M. Rines
Keyword(s):  
Natural Resource ◽  
Input Data ◽  
Oil Spills ◽  
Model Simulation ◽  
Biological Effects ◽  
Type A ◽  
Model System ◽  
Biological Data ◽  
Impact Model ◽  
Using Data

ABSTRACT SIMAP (Spill Impact Model Application Package) is Applied Science Associates’ spill impact model system. The system is designed to simulate the fates and effects of spilled oils and fuels, to allow for an evaluation of the effectiveness of spill response activities, and to evaluate the probabilities of trajectories and resulting impacts. The physical fates and biological effects models in SIMAP are based on those in the CERCLA type A model for natural resource damage assessments (NRDAs), documented in French et al. (1996a). SIMAP may be used for real-time spill simulation, contingency planning, and natural resource damage and ecological risk assessments. The physical fates and biological effects models in SIMAP and the NRDA type A model were validated using data from 27 oil spills. The success of a model simulation depends on both the algorithms and the accuracy of the input data. The results of the validation, described herein, verify the model algorithms. The most important input data in determining accuracy of results are winds, currents, and biological abundances of the most affected species. Thus the model system, when applied with accurate environmental and biological data inputs, can quantitatively and objectively estimate the impacts of oil spills into aquatic systems.

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