Computer Simulation of Illustrating the Impact of Uneven Saline Distribution on Thermal Lesion During Radiofrequency Ablation Treatments

Author(s):  
Huang-Wen Huang ◽  
Lin Hui

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256076
Author(s):  
Soroush Ghomashchi ◽  
Cari M. Whyne ◽  
Tricia Chinnery ◽  
Fayez Habach ◽  
Margarete K. Akens

Thermal therapies such as radiofrequency ablation (RFA) are gaining widespread clinical adoption in the local treatment of skeletal metastases. RFA has been shown to successfully destroy tumor cells, yet the impact of RFA on the quality of the surrounding bone has not been well characterized. RFA treatment was performed on femora of rats with bone metastases (osteolytic and osteoblastic) and healthy age matched rats. Histopathology, second harmonic generation imaging and backscatter electron imaging were used to characterize changes in the structure, organic and mineral components of the bone after RFA. RFA treatment was shown to be effective in targeting tumor cells and promoting subsequent new bone formation without impacting the surrounding bone negatively. Mineralization profiles of metastatic models were significantly improved post-RFA treatment with respect to mineral content and homogeneity, suggesting a positive impact of RFA treatment on the quality of cancer involved bone. Evaluating the impact of RFA on bone quality is important in directing the growth of this minimally invasive therapeutic approach with respect to fracture risk assessment, patient selection, and multimodal treatment planning.



2018 ◽  
Author(s):  
Naama Katzin

Recent studies in the field of numerical cognition quantify the impact of physical properties of an array on its enumeration, demonstrating that enumeration relies on the perception of these properties. This paper marks a shift in reasoning as it changes the focus from demonstrating this effect to explaining it. Interestingly, we were inspired by one of the very first articles in the field, “The power of numerical discrimination” by Stanley Jevons that was published in Nature in 1871. In his report, Jevons attempts to answer the question of how many objects can be perceived in “a single mental beat of attention”. We relate directly to Jevons’s records, putting forward a plausible heuristic mechanism that relies on the physical geometrical properties of the arrays to be enumerated. We use a mathematical theorem and computer simulation to show that the shape of the convex hull, the smallest polygon containing all dots in an array, is a good predictor of numerosity. We show that convex hull downsamples the spatial data, allowing quick and fairly accurate numerical estimation. Moreover, convex hull predictability changes as numerosity grows, corresponding to the psychophysical curve of enumeration shown by Jevons and many others that followed.



2012 ◽  
Vol 468-471 ◽  
pp. 1380-1383
Author(s):  
Hui Wang ◽  
Yu Xin Wang

Rigidity of oil film is an important hydrostatic support performance of the slipper pair. This paper establishes the mathematics model of hydrostatic support structure on the basis of considering secondary force. And establish the simulation model of rigidity of oil film by using the toolbox of Simulink. Study the dynamic characteristics of rigidity of oil film under the influence of secondary force through computer simulation. And reach a conclusion that the impact of secondary force on rigidity of oil film has a relationship with friction coefficient and work pressure.



Designs ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 42 ◽  
Author(s):  
Ebrahim Solgi ◽  
Zahra Hamedani ◽  
Shahab Sherafat ◽  
Ruwan Fernando ◽  
Farshid Aram

The continuing importance of energy conservation in the building sector has drawn major attention to energy audits of existing buildings in different climates. In this paper, the energy conservation potential of a residential building located in Iran’s cold climate was investigated through an analysis of its actual energy consumption and through computer simulation. The building base-load was determined using a linear regression method based on existing energy bills, and was used to validate the computer simulation of its energy usage. The impact of typical energy saving solutions was evaluated for three cost refurbishment scenarios: low, medium and high. The results show that the existing construction and envelope materials fail to meet the national standards of Iran, but insulating the envelope was found to be a more cost-effective measure than modifying the windows. The results also demonstrate that although the use of energy-saving solutions has a significant impact on energy consumption, even the most economic solutions investigated will have a payback period longer than one decade. Thus, with current energy prices the reviewed energy conservation strategies are not economically justified in Iran from the consumer perspective, as investment in the methods considered typical in other parts of the world will not show a return for at least a half-century.



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