Experimental investigation of gamma-ray interaction parameters and buildup factors in lanthanide compounds: Insights into penetration depth.

This experimental investigation focuses on the gamma-ray interaction parameters and the buildup factor in lanthanide compounds (CeO2, Ce(SO4)2, Dy2(SO4)3, C3O9Sm2, C3Gd2O9, Pr2O3). These compounds were exposed to weak radioactive gamma sources with energies of 356, 511, 662, 1173, 1275, and 1332 keV by adopting narrow and broad beam geometry experimental arrangements. The incident and transmitted radiation intensities were measured using a NaI (Tl) detector. Experimentally measured values of mass attenuation coefficient and effective atomic number of lanthanide compounds were found to be in precise agreement with theoretical values obtained from NIST XCOM and Direct-Zeff database respectively. Additionally, the experimentally determined buildup factor values were compared with energy absorption buildup factor (EABF) and exposure buildup factor (EBF) values obtained from Phy-X/PSD software, providing insights into the gamma-ray penetration depth in terms of mean free path (MFP). At 356 keV, the EABF analysis showed that most compounds had a penetration depth of around 8 mean free paths. In contrast, the EBF analysis indicated penetration depths exceeding 10 mean free paths for all compounds except Ce (SO4)2. This new approach holds immense potential for transformative advancements in medical diagnostics, therapy, and the development of innovative technologies in nuclear sciences.

Multifunctional Ln-MOF Luminescent Probe for Efficient Sensing of Fe3+, Ce3+, and Acetone.

A new series of five three-dimensional Ln(III) metal-organic frameworks (MOFs) formulated as [Ln4(µ6-L)2(µ-HCOO)(µ3-OH)3(µ3-O)(DMF)2(H2O)4] n {Ln3+ = Tb3+ (1), Eu3+ (2), Gd3+ (3), Dy3+ (4), and Er3+ (5)} was successfully obtained via a solvothermal reaction between the corresponding lanthanide(III) nitrates and 2-(6-carboxypyridin-3-yl)terephthalic acid (H3L). All of the obtained compounds were fully characterized, and their structures were established by single-crystal X-ray diffraction. All products are isostructural and possess porous 3D networks of the fluorite topological type, which are driven by the cubane-like [Ln4(µ3-OH)3(µ3-O)(µ-HCOO)]6+ blocks and µ6-L3- spacers. Luminescent and sensing properties of 1-5 were investigated in detail, revealing a unique capability of Tb-MOF (1) for sensing acetone and metal(III) cations (Fe3+ or Ce3+) with high efficiency and selectivity. Apart from a facile recyclability after sensing experiments, the obtained Tb-MOF material features a remarkable stability in a diversity of environments such as common solvents, aqueous solutions of metal ions, and solutions with a broad pH range from 4 to 11. In addition, compound 1 represents a very rare example of the versatile Ln-MOF probe capable of sensing Ce3+ or Fe3+ cations or acetone molecules.

Novel materials based on DNA-CTMA and lanthanide (Ce(3+) , Pr(3+) ).

New, deoxyribonucleic acid (DNA) based compounds, functionalized with hexadecyltrimethylammonium chloride (CTMA) and lanthanide hydroxide nanoparticles were synthesized. The spectral measurements suggest that between the DNA-CTMA complex and the lanthanide (III) ions a chemical interaction takes place. The obtained materials exhibit an improved fluorescence efficiency, showing a potential interest for application in photonics, and more particularly, in light emitting devices. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 613-617, 2016.