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The thyroid biokinetic model of radioactive I-131 was re-evaluated using a refined nine-compartmental model and applied to twelve thyroid cancer patients. In contrast to the simplified four-compartmental model regulated by the ICRP-56 report, the revised model included nine compartments specified in the ICRP-128 report, namely, oral, stomach, body fluid, thyroid, whole body, liver, kidney, bladder, and remainder (i.e., the whole body minus kidney and bladder). A self-developed program run in MATLAB was designed to solve the nine first-order simultaneous linear differential equations. The model was realized in standard and simplified versions. The latter neglected two feedback paths (body fluid to oral, i31, and kidney to the whole body, i87) to reduce computations. Accordingly, the biological half-lives for the major compartments (thyroid and body fluid + whole body) were 36.00 ± 15.01, 15.04 ± 5.63, 34.33 ± 15.42, and 14.83 ± 5.91 of standard and simplified version. The correlations between theoretical and empirical data for each patient were quantified by the dimensionless AT (agreement) index and, the ATtot index integrated each individual AT of a specific organ of one patient. Since small AT values indicated a closer correlation, the obtained range of ATtot (0.048 ± 0.019) proved the standard model’s reliability and high accuracy, while the simplified one yielded slightly higher ATtot (0.058 ± 0.023). The detailed outcomes among various compartments of twelve patients were calculated and compared with other researchers’ work. The correlation results on radioactive I-131 evolution in thyroid cancer patients’ bodies are instrumental in viewpoint of radioactive protection of patients and radiological personnel.

We report a novel approach of directly labeling the radioisotope Tc99m with magnetite ([Fe.sub.3][O.sub.4]) nanoparticles for diagnostic applications. The magnetite nanoparticles were first synthesized from aqueous solutions of Fe(II) and Fe(III) chloride, with addition of ammonium hydroxide. Subsequently, the radioisotope Tc-99m were mixed directly into the reaction solution with ferrite precipitation. The labeling efficiency, of ferrite nanoparticles bound with Tc-99m, is above 99%. As prepared radioactive ferrite nanoparticles were intravenously injected into rats. The biodistribution of radioactivity, monitored by gamma-camera, has shown the uptake of radiomicrospheres can be restrained and transferable in vivo in the living animals by applying an external Nd-Fe-B magnet. Final fate of the radiomierospheres is to be related with the surface charge of particles. Modification of surface charge of the radiolabeled ferrite nanobeads for clinical targeted diagnosis is discussed. Index Terms--Ferrite, nanoparticles, radioisotope.

In this paper, we present spectroscopic ellipsometry measurements of (MA0.13FA0.87)PbI3 single crystals assessed at photon energies of 0.73–6.42 eV and at temperatures between 4.4 and 400 K. At room temperature, the refractive index was dispersed as a function of frequency, which is typical of a semiconductor. The absorption spectrum exhibited several electronic transitions. We estimated a room temperature direct band gap of 1.66 ± 0.02 eV and exciton binding energy of 40 meV. With decreasing temperature, the refractive index increased. The room-temperature thermo-optic coefficients were −1.7 × 10−4 and −2.5 × 10−4 K−1 at wavelength of 600 and 1200 nm. The exciton peak position and bandgap energy exhibited a redshift, which was attributed to a reverse ordering of the band structures. Additionally, an anomaly in exciton peak position and bandgap occurred at approximately 100–200 K due to the structural phase transition. This phenomenon was associated with the coexistence of MA/FA-disordered and MA/FA-ordered domains. Our results provide a foundation for the technological development of lead halide perovskites-based photonic devices at various temperatures. [ABSTRACT FROM AUTHOR]