Nazia Afrin^a, Yijin Mao^a, Yuwen Zhang^a,*, J. K. Chen^a, Robin Ritter^b, Alan Lampson^b, Jonathan Stohs^c

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-8, 2016, DOI:10.5098/hmt.7.7

Abstract A three-dimensional numerical simulation is conducted for a complex process in a laser-material system, which involves heat and mass transfer in a compressible gaseous phase and chemical reaction during laser irradiation on a urethane paint coated on a stainless steel substrate. A finite volume method (FVM) with a co-located grid mesh that discretizes the entire computational domain is employed to simulate the heating process. The results show that when the top surface of the paint reaches a threshold temperature of 560 K, the polyurethane starts to decompose through chemical reaction. As a result, combustion products CO₂, More >

Michel Drouet, Nancy Grenier, Francis Hérodin

European Cytokine Network, Vol.23, No.2, pp. 56-63, 2012, DOI:10.1684/ecn.2012.0306

Abstract We have re-evaluated the benefit of using erythropoietin (Epo) as a pleiotropic cytokine to counteract hematological and extra-hematological toxicity following lethal irradiation. B6D2F1 mice were exposed to a dose of 9 Gy gamma radiation resulting in 90% mortality at 30 days, and then injected with stem cell factor, FLT-3 ligand, thrombopoietin and interleukin-3 [i.e. SFT3] at two and 24 hours with or without Epo (1,000 IU/kg) at 2 hours and day 8. As controls, two groups of irradiated mice were given only Epo or Phosphate-buffered saline. Epo synergized with SFT3 to rescue lethally-irradiated mice from More >

Ze-Wei Zhang^*, Hui Wang^†, Qing-Hua Qin^∗,‡

Molecular & Cellular Biomechanics, Vol.9, No.1, pp. 31-54, 2012, DOI:10.3970/mcb.2012.009.031

Abstract This paper presents a hybrid finite element model for describing quantitatively the thermal responses of skin tissue under laser irradiation. The model is based on the boundary integral-based finite element method and the Pennes bioheat transfer equation. In this study, temporal discretization of the bioheat system is first performed and leads to the well-known modified Helmholtz equation. A radial basis function approach and the boundary integral based finite element method are employed to obtain particular and homogeneous solutions of the laser-tissue interaction problem. In the boundary integral based finite element formulation, two independent fields are More >

Arunn Narasimhan^*, Kaushal Kumar Jha

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-8, 2011, DOI:10.5098/hmt.v2.3.3005

Abstract Pan Retinal photocoagulation (PRP), a retinal laser surgical process, is simulated using a three-dimensional bio-heat transfer numerical model. Spots of two different type of array, square array of 3 × 3 spots and a circular array of six spots surrounding a central spot, are sequentially irradiated. Pennes bio-heat transfer model is used as the governing equation. Finite volume method is applied to find the temperature distribution due to laser irradiation inside the human eye. Each spot is heated for 100 ms and subsequently cooled for 100 ms with an initial laser power of 0.2 W. More >

E. Hayward¹, C. Deo¹

CMC-Computers, Materials & Continua, Vol.16, No.2, pp. 101-116, 2010, DOI:10.3970/cmc.2010.016.101

Abstract Damage cascades representative of those that would be induced by neutron irradiation have been simulated in systems of pure iron and iron containing 0.01 at.% hydrogen. Results from molecular dynamics simulations using three different embedded-atom method (EAM) type potentials are compared for primary knock-on atom energies of 5, 10, and 20 keV to assess the effect of hydrogen on the primary damage state. We examine the influence of hydrogen on the primary damage state due to a single radiation cascade. These results can serve as an atomistic database for methods and simulations for long time More >

N. J. Lee, C.R. Welch¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.1, pp. 11-12, 2009, DOI:10.3970/icces.2009.013.011

Abstract Carbon nanotubes have significant potential as the basis for super infrastructure material. The shear modulus of carbon nanotube ensembles is relatively low, comparable to graphite, as the carbon nanotubes interact via weak van der Waals forces. Unmodified, their intermolecular interactions are insufficient to take full advantage of the extraordinarily high strengths predicted for carbon nanotube-based fibers. Thus, a key to their use in high-strength materials is developing strong bonds between these molecules. In this study, we examine the potential development of covalent bonds between carbon nanotube pairs cross-bonded by proton bombardment using molecular dynamics simulation. More >

Jianhua Zhou^∗, J. K. Chen^†, Yuwen Zhang^‡

Molecular & Cellular Biomechanics, Vol.4, No.1, pp. 27-40, 2007, DOI:10.3970/mcb.2007.004.027

Abstract A bioheat transfer approach is proposed to study thermal damage in biological tissues caused by laser radiation. The laser light propagation in the tissue is first solved by using a robust seven-flux model in cylindrical coordinate system. The resulting spatial distribution of the absorbed laser energy is incorporated into the bioheat transfer equation for solving temperature response. Thermal damage to the tissue is assessed by the extent of denatured protein using a rate process equation. It is found that for the tissue studied, a significant protein denaturation process would take place when temperature exceeds about More >

Marcelo de Castro Pazos*, Cristina Pacheco-Soares*, Newton Soares da Silva*, R.A. DaMatta**, M.T.T. Pacheco*

BIOCELL, Vol.27, No.3, pp. 301-309, 2003, DOI:10.32604/biocell.2003.27.301

Abstract The effects of Photodynamic Therapy using 2^nd generation photosensitizers have been widely investigated aiming clinical application treatment of solid neoplasms. In this work, ultrastructure changes caused by the action of two 2^nd generation photosensitizers and laser irradiation on CHO-K1 and HeLa (neoplastic) cells were analyzed by transmission electron microscopy. Aluminum phthalocyanine chloride, aluminum phthalocyanine tetrasulfonate chloride and radiation from a semiconductor laser at a fluency of 0.5 J/ cm² (Power=26mW; λ=670nm) were used. The results showed induction of apoptosis. Such alterations where observed in HeLa but not in CHO-K1 cells after Aluminum phthalocyanine tetrasulfonate chloride (AlPcS₄) photodynamic More >

Marc David¹, Luis Souhami¹, Armen Aprikian²

Canadian Journal of Urology, Vol.9, No.4, pp. 1599-1601, 2002

Abstract A case of post renal acute renal failure secondary to radiation therapy for prostate cancer is described. Severe bladder inflammatory reaction, leading to bilateral ureteric obstruction, occurred after a moderate dose of radiotherapy (6400 cGy in 35 fractions). At a follow-up time of 8 years, the patient has fully recovered and remains disease-free. To our knowledge, this complication has never been described previously. Given the thrust in prostate cancer treatment toward dose escalation this complication could become more frequent. More >