Sciences et Technologies - العلوم و التكنولوجيا
http://e-biblio.univ-mosta.dz/handle/123456789/493
2024-03-29T06:46:14ZApplications of computational animal models in radiation therapy research
http://e-biblio.univ-mosta.dz/handle/123456789/9784
Applications of computational animal models in radiation therapy research
M'hamed Bentourkia, Mahdjoub Hamdi and Faiçal A A Slimani
In this chapter, we cover the usefulness and extent of performing computations using small animal models in cancer treatment with radiation therapy. Since mice are the most utilized animal models in cancer research, we restrict our discussion to the mouse model. The wide adoption of mice among other small animals is justified by their small size, in addition to the fact that they are inexpensive, easy to breed and to manipulate, reproduce rapidly, and can be genetically modified.
2018-12-01T00:00:00ZUse of cardiorespiratorycoherence to separateSpectral bands of the heart rate variability
http://e-biblio.univ-mosta.dz/handle/123456789/9783
Use of cardiorespiratorycoherence to separateSpectral bands of the heart rate variability
M. Daoud, P. Ravier and O. Buttelli
Regulation of heart rate variability (HRV) isdependent on the autonomicnervous system (ANS). The regulation is achieved by the two ANS activity branches distribution, namely the parasympathetic and the sympatheticactivities. Their fluctuations can be observed in the HRV signal spectral domain through respective dissociated frequency domains. Power spectrum parameters in low frequency (LF) and high frequency (HF) domains are classically estimated using predetermined fixed frequency ranges which are [0.04–0.15 Hz] band for LF domain and [0.15–0.4 Hz] band for HF domain. However, the 0.15 Hz frequency threshold is controversial in dynamic situations or positions changing. Several studies advanced that the observed cardiac and respiratory oscillation interactions could reflect the functionality of the ANS. These interactions can be estimated by the cardiorespiratory spectral coher-encetoolwhich quantifies the existence and strength of linearity between the two modes. We propose in this paper to jointly use the heart rate variability (HRV) and respiration modes by exploiting the car-diorespiratory spectral coherence tool for the time-varying frequency threshold definition between LF and HF bands. The instantaneous center frequency computed on the time-frequency coherence estimatoris the proposed variable threshold (VT). The VT method was implemented on both simulated data and real data acquired from the experimental orthostatic test protocol with 10 healthy subjects. The classical 0.15 Hz fixed threshold (FT) and the individual time-dependent spectral boundaries method (AT) using the lower limit of the respiratory HF band as a time-varying threshold are used for comparison. The proposed VT strategy makes it possible to obtain: (i) a strengthened data-dependent definition of boundaries for the HF domain; (ii) instantaneous estimations of the LF and HF band energies; (iii) a better discrimination between the two positions SUPINE and UPRIGHT of the classical orthostatic test.
2018-01-01T00:00:00ZG4DARI: Geant4/GATE based Monte Carlo simulation interface for dosimetry calculation in radiotherapy.
http://e-biblio.univ-mosta.dz/handle/123456789/9782
G4DARI: Geant4/GATE based Monte Carlo simulation interface for dosimetry calculation in radiotherapy.
Slimani F. AA, Hamdi M, Bentourkia M
Monte Carlo (MC) simulation is widely recognized as an important technique to study the physics of particle interactions in nuclear medicine and radiation therapy. There are different codes dedicated to dosimetry applications and widely used today in research or in clinical application, such as MCNP, EGSnrc and Geant4. However, such codes made the physics easier but the programming remains a tedious task even for physicists familiar with computer programming. In this paper we report the development of a new interface GEANT4 Dose And Radiation Interactions (G4DARI) based on GEANT4 for absorbed dose calculation and for particle tracking in humans, small animals and complex phantoms. The calculation of the absorbed dose is performed based on 3D CT human or animal images in DICOM format, from images of phantoms or from solid volumes which can be made from any pure or composite material to be specified by its molecular formula. G4DARI offers menus to the user and tabs to be filled with values or chemical formulas. The interface is described and as application, we show results obtained in a lung tumor in a digital mouse irradiated with seven energy beams, and in a patient with glioblastoma irradiated with five photon beams. In conclusion, G4DARI can be easily used by any researcher without the need to be familiar with computer programming, and it will be freely available as an application package.
2018-04-28T00:00:00ZElastic, magnetic and electronic properties of ferrimagnetic double perovskite Sr2MnWO6 using GGA + U and mBJ-GGA
http://e-biblio.univ-mosta.dz/handle/123456789/8288
Elastic, magnetic and electronic properties of ferrimagnetic double perovskite Sr2MnWO6 using GGA + U and mBJ-GGA
Djelti, Benbella; Bentata, Samir; Benstaali, Wissam; Abbad, Amel; Benosman, W.; Benmalem, Yasmine; Cherid, Samira
The present work performs self-consistent ab-initio calculation through full-potential linearized augmented plane wave (FP-LAPW) method within the frame work of the spin-polarized density functional theory (DFT), to study the structural, electronic, magnetic and elastic properties of the double perovskite Sr2MnWO6 using generalized gradient approximation (GGA) described by Perdew–Burke–Ernzerhof (PBE), GGA + U and mBJ-GGA. The obtained results show that Sr2WMnO6 is stable in the ferrimagnetic state; the electronic properties show a half-metallic behavior using GGA + U and mBJ-GGA. Elastic properties show that our compound is fragile, stiff and anisotropic.
2018-08-18T00:00:00Z