Internal dosimetry of 64Cu-DOX-loaded microcapsules by Monte Carlo method.

Some of the issues regarding introducing new radiocompounds in nuclear medicine are the distribution patterns, delivered dose to different organs, diagnostic abilities and side effects. In this study, in order to assess the biodistribution of 64Cu-DOX-loaded microcapsules, rats were IV-injected with the microcapsules, and 1, 4, 14, and 24 h later, the activities of the targeted organs were measured (%ID/g). The accumulated activities were achieved by %ID/g curves, and S-factors were obtained by MCNP outputs. The MIRD formulation and Monte Carlo method were used to determine the absorbed dose in the target organs. The biodistribution data and PET-CT images showed that the lungs were where the majority of activity was seen. According to MIRD and MCNP, the maximum dose delivered in the lungs was 5.79E+01 mGy/MBq and 4.70E+01 mGy/MBq, respectively. Also, the effective dose was 1.2E+01 for MIRD and 8.31E+00 mSv/MBq for MCNP. These results indicate that 64Cu-DOX microcapsules can be considered a new radiocompound in pulmonary imaging, and MCNP simulation can be a reliable method for internal dosimetry.

Dose evaluation of auger electrons emitted from the 119Sb in cancer treatment.

The purpose of this study is dose evaluation induced by Auger electrons emitted from 119Sb in a tumor and surrounding healthy tissues. Dose evaluation was done by using the MCNP6 code in the tumor and healthy tissue (in thyroid follicles) and the calculated absorbed dose was significant. Most of the Auger electron energy emitted from 119Sb deposits in the decay position, so the effectiveness of Auger electrons should not be ignored also an accurate target therapy can be planned by them.

Experimental study of carbon dioxide absorption by Fe2O3@glutamine/NMP nanofluid.

In this study, for the first time, the nanoparticle (NP) of Fe2O3@glutamine (C5H10N2O3) was synthesized to improve the Fe2O3 properties in absorbing carbon dioxide (CO2) using the base fluid of hydrous N-methyl-2-pyrrolidone (NMP) solution (50 wt%), as a physically powerful CO2 absorbent. To do this, several nano-NMP solutions, in different weight percentages of NPs, were first prepared. Then, in a batch setup, the nano-NMP solutions were directly exposed to CO2 gaseous (at the pressures of 20, 30, and 40 bar) to clarify the effects of the mass percentage of NPs and initial pressure on CO2 absorption. Results clearly illustrated that Fe2O3 nanofluid was not stable more than 0.025 wt%. However, Fe2O3@glutamine nanofluid was stable approximately two times more than Fe2O3 nanofluid due to the presence of glutamine as a hydrophilic agent in the structure of Fe2O3@glutamine. Moreover, in comparison to the base fluid (NMP solution), although Fe2O3 increased CO2 absorption up to 9.14%, Fe2O3@glutamine NPs caused the CO2 absorption to increase up to 19.41%, which can be determined as the chemical reactions of two amino groups in the glutamine structure with CO2 and also higher stability of Fe2O3@glutamine NPs compared to bare Fe2O3 NPs. To achieve accurate results, all the mentioned experiments were repeated 5 times. The performance of Fe2O3 and Fe2O3@glutamine NPs after the fifth trial reduced by less than 3.5%, which reveals that the synthesized NPs had almost stable efficiency throughout their applications.

Determination of Swelling Behavior and Mechanical and Thermal Resistance of Acrylamide-Acrylic Acid Copolymers under High Pressures and Temperatures.

Unwanted water production is a serious problem accompanying oil extraction especially in oil-fractured reservoirs. An effective approach to tackle this issue is to utilize gels as a blockage agent. In this paper, an effective series of preformed particle gels (PPGs) was synthesized by a free radical copolymerization of acrylamide and acrylic acid [poly(AAm-co-AA)] copolymers. The key factors of synthesis experiments, gelation time, drying behavior, swelling capacity (in CaCl2·2H2O, MgCl2·6H2O, BaCl2·2H2O, KCl, NaCl, and LiCl saline solutions with 200,000 ppm concentration and pH from 3 to 8), and mechanical and thermal resistance of the synthesized PPGs (with a homemade apparatus) were elucidated. Laboratory results revealed that the prepared PPG sample 1 (9.65 mole ratio of AAm/AA and 6 mol % of MBA) would be a good candidate for controlling water in oil and gas reservoirs with a salinity, pressure, and temperature of up to 200,000 ppm, 300 bar, and 170 °C, respectively, and pH values ranging from 3 up to 8.