scholarly journals Labeling of ethylenediamine tetramethylene phosphonate with 153Sm and 177Lu,Comparison Study

2020 ◽  
pp. 1-7
Author(s):  
Hesham MH Zakaly ◽  
Mostafa Y. A. Mostafa ◽  
M Zhukovsky
Keyword(s):  
Computer Software ◽  
High Energy ◽  
Dose Assessment ◽  
Ionic Form ◽  
Comparison Study ◽  
Bone Surface ◽  
Surface Absorption ◽  
Beta Particles ◽  
Cumulative Activity ◽  
Kinetics Of

Background 177Lu and 153Sm are perspective radionuclides in terms of applying to nuclear medicine. High-energy beta particles and the relative half-life of the radionuclide are used to achieve an effective palliative treatment of bone metastases. Materials and methods The absorbed doses in different organs and tissues of 177Lu and 153Sm in ionic form and labeled with EDTMP are determined by IDAC-Dose 2.1 (Internal Dose Assessment by Computer) software and WinAct software which used to calculate cumulative activity. 177Lu and 153Sm are lanthanide radionuclide which actively accumulates in liver and bone when used in ionic form. In the case of labeling with EDTMP, the distribution and elimination of the drug occur according to the kinetics of a carrier, EDTMP. The using of osteotropic (Describing any drug etc. that is attracted to, and targets bone) complex allows creating a large dose in the pathological areas and minimizing damages in healthy organs and tissues. Results The effective dose per administered activity is 0.189 mSv/MBq for 177Lu-ionic form, 0.232 mSv/MBq for 153Sm-ionic form and 0.242 mSv/MBq for 177Lu-EDTMP and 0.139 mSv/MBq for 153sm-EDTMP. Conclusion 177Lu and 153Sm labeled with EDTMP are decreasing the liver dose absorption and increasing the bone surface absorption for more effective treatment and minimize side effects.

Neutron dose evaluation of Elekta Linac at two energies (10 & 18 MV) by MCNP code and comparison with experimental measurements

2014 ◽  
Vol 6 (1) ◽  
pp. 1006-1015
Author(s):  
Negin Shagholi ◽  
Hassan Ali ◽  
Mahdi Sadeghi ◽  
Arjang Shahvar ◽  
Hoda Darestani ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Measurement Data ◽  
Calculated Data ◽  
High Energy ◽  
Neutron Dose ◽  
Dose Assessment ◽  
Photon Flux ◽  
Dose Equivalent ◽  
Monte Carlo Techniques ◽  
Neutron Dose Equivalent

Medical linear accelerators, besides the clinically high energy electron and photon beams, produce other secondary particles such as neutrons which escalate the delivered dose. In this study the neutron dose at 10 and 18MV Elekta linac was obtained by using TLD600 and TLD700 as well as Monte Carlo simulation. For neutron dose assessment in 2020 cm2 field, TLDs were calibrated at first. Gamma calibration was performed with 10 and 18 MV linac and neutron calibration was done with 241Am-Be neutron source. For simulation, MCNPX code was used then calculated neutron dose equivalent was compared with measurement data. Neutron dose equivalent at 18 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 3.3, 4, 5 and 6 cm. Neutron dose at depths of less than 3.3cm was zero and maximized at the depth of 4 cm (44.39 mSvGy-1), whereas calculation resulted  in the maximum of 2.32 mSvGy-1 at the same depth. Neutron dose at 10 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 2.5, 3.3, 4 and 5 cm. No photoneutron dose was observed at depths of less than 3.3cm and the maximum was at 4cm equal to 5.44mSvGy-1, however, the calculated data showed the maximum of 0.077mSvGy-1 at the same depth. The comparison between measured photo neutron dose and calculated data along the beam axis in different depths, shows that the measurement data were much more than the calculated data, so it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry in linac central axis due to high photon flux, whereas MCNPX Monte Carlo techniques still remain a valuable tool for photonuclear dose studies.

Energy Intakes of Ultraendurance Cyclists During Competition, an Observational Study

2012 ◽  
Vol 22 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Katherine E. Black ◽  
Paula M.L. Skidmore ◽  
Rachel C. Brown
Keyword(s):  
Observational Study ◽  
Energy Intake ◽  
Energy Requirement ◽  
Negative Relationship ◽  
Computer Software ◽  
High Energy ◽  
Energy Deficit ◽  
Food Diary ◽  
Food And Drink ◽  
And Performance

Endurance events >10 hr are becoming increasingly popular but provide numerous physiological challenges, several of which can be attenuated with optimal nutritional intakes. Previous studies in ultraendurance races have reported large energy deficits during events. The authors therefore aimed to assess nutritional intakes in relation to performance among ultraendurance cyclists. This observational study included 18 cyclists in a 384-km cycle race. At race registration each cyclist’s support crew was provided with a food diary for their cyclist. On completion of the race, cyclists were asked to recall their race food and drink intakes. All food and fluids were analyzed using a computer software package. Mean (SD) time to complete the race was 16 hr 21 min (2 hr 2 min). Mean (SD) energy intake was 18.7 (8.6) MJ, compared with an estimated energy requirement for the race of 25.5 (7.4) MJ. There was a significant negative relationship between energy intake and time taken to complete the race (p = .023, r2 = −.283). Mean (SD) carbohydrate, fat, and protein intakes were 52 (27), 15.84 (56.43), and 2.94 (7.25) g/hr, respectively. Only carbohydrate (p = .015, r2 = −.563) and fat intake (p = .037, r2 = −.494) were associated with time taken to complete the race. This study demonstrates the difficulties in meeting the high energy demands of ultraendurance cycling. The relationship between energy intake and performance suggests that reducing the energy deficit may be advantageous. Given the high carbohydrate intakes of these athletes, increasing energy intake from fat should be investigated as a means of decreasing energy deficits.

Diffusion Enhancement in Glassy Metals Under Non-Equilibrium Conditions

1995 ◽  
Vol 400 ◽  
Author(s):  
S. Bellini ◽  
G. Mazzone ◽  
A. Montone ◽  
M. Vittori-antisari Enea ◽  
C.R. Casaccia
Keyword(s):  
Free Volume ◽  
Growth Kinetics ◽  
Bulk Diffusion ◽  
High Energy ◽  
First Case ◽  
Diffusion Enhancement ◽  
Glass Crystal ◽  
Kinetics Of ◽  
Crystal Interface ◽  
Diffusion Properties

AbstractThe diffusion properties of a Ni-Zr metallic glass formed at the interface of a bulk diffusion couple have been studied in conditions far from a fully relaxed state. The growth kinetics of the interface film have been enhanced by both plastic deformation and high energy electron irradiation. Different results have been obtained in the two cases, since in the first case the film grows exponentially with time, while in the second case the usual square root dependence on time is observed. This behaviour has been interpreted as a consequence of the annihilation kinetics of the excess free volume introduced in the glass by the above methods. Two different mechanisms of free volume annihilation , namely exchange with a crystal vacancy at the glass-crystal interface and structural relaxation in the bulk glassy phase have been considered to be operative so that the nature of the growth kinetics has been found to depend on the mechanism predominant in each experimental condition.

scholarly journals DEGRADATION KINETICS OF HIGH ENERGY PHOSPHATES IN THE RABBIT BRIN USING NMR-SPECTROSCOPY

1985 ◽  
Vol 19 (10) ◽  
pp. 1073-1073
Author(s):  
N Herschkowitz ◽  
F Stocker ◽  
E Bossi ◽  
M Stoller ◽  
W Aue ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Degradation Kinetics ◽  
High Energy ◽  
High Energy Phosphates ◽  
Kinetics Of

Kinetics of Electron Transfer Reaction between Co(II) and Chlorate Ions: Experimental and Modeling Study

2021 ◽  
Vol 43 (5) ◽  
pp. 559-559
Author(s):  
Mahwish Mobeen Khan and Syed Mumtaz Danish Naqvi Mahwish Mobeen Khan and Syed Mumtaz Danish Naqvi
Keyword(s):  
Electron Transfer ◽  
Transfer Reaction ◽  
High Energy ◽  
Electron Transfer Reaction ◽  
Maximum Likelihood Estimates ◽  
Oxidation Catalyst ◽  
Standard Entropy ◽  
Rate Of Reaction ◽  
Kinetics Of ◽  
Activated Complex

This research article reports original experimental and modeling detail of kinetics of the electron transfer reaction between Co(II) and chlorate ions in acetic acid solution. Design of experiment methodology has been employed to elucidate the effects of temperature and initial concentrations of reactants on the rate of reaction. Levenberg-Marquardt method has been used to fit processed kinetic data (temperatures, initial concentrations of reactants, and concentrations and rates of production of Co(III)) on to various possible rate equations. This algorithm provides a proficient mean for compensating the capricious effects of the experimental process variables and results in the maximum likelihood estimates of the kinetic parameters. The most significant rate law has been selected, on the basis of statistical analyses of the residuals between the predicted and experimental rates. The analyses suggest that the intrinsic rate of reaction is proportional to first power of chlorate concentration but for Co(II) the order is fractional (0.7455 ≈ and#190;). The effect of temperature on the observed rate constant (precision = 0.02 %) is excellently described by the Arrhenius and Eyring equations and the sluggish nature of the reaction is clearly manifested by the high energy (andgt; 93 kJ/mol), negative entropy (-28.5286 J/mol-K) and very small equilibrium constant of activation. Further fairly negative standard entropy of activation shows there is usually considerable rearrangement of energy among various degrees of freedom during the formation of activated complex and proposes an associative mechanism for formation of the activated complex. This research is performed to develop a kinetic model for the electron transfer reaction between Co(II) and chlorate ion. As a result, a redox couple of Co(II)/Co(III) has been formed which is used as a potent oxidation catalyst in chemical industries.

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