Radiochemistry Commons^™

Radiotheranostics For Gynecological Pathologies, Joni Sebastiano

Dissertations, Theses, and Capstone Projects

Molecular imaging, specifically positron emission tomography (PET), is vital for detecting disease and understanding its biological makeup. The exploitation of radiolabeled antibodies for PET imaging has proven to be indispensable to the field of molecular imaging over the last several decades. The development of radioimmunoconjugates for use in immunoPET has not only allowed for the sensitive, specific, and high-resolution detection of disease, but has also enabled a deeper understanding of the disease biology, ultimately guiding more personalized therapeutic strategies. Most typically, this technology is harnessed for the diagnosis and treatment of cancer, however more recently, the field has explored the …

At The Crossroads Of Traditional And Nuclear Forensics: Decontaminating Radiologically Contaminated Dna Evidence Using Magnetic Beads, Rin Nyx Ruby

UNLV Theses, Dissertations, Professional Papers, and Capstones

Known for its impressive discriminatory power, deoxyribonucleic acid (DNA) fingerprinting stands as the “gold standard” of forensic investigation. However, complications arise when such evidence is contaminated with radioactive material. Though biological samples exposed to ionizing radiation can still yield comprehensive DNA profiles, most forensic laboratories lack the facilities which meet the safety and security requirements necessary for handling radioactive material. While nuclear facilities can decontaminate samples prior to forensic analysis, conventional methods for radiological decontamination – such as mechanical cleaning and chemical washes – may degrade the quality of the forensic evidence. The purpose of this study is to evaluate …

Impact Of Collodion Thickness On Fission Track Generation Within Lexan Employed For Nuclear Forensic Analyses, Ryan K. Chapman, Zachary P. Meisel, Abigail A. Bickley

Faculty Publications

We report results from a computational study of fission track damage within a Lexan substrate caused by ²³⁵U suspended within a collodion film of varied thickness. MCNP6.3 was used to model energy deposition and displacements per atom within a Lexan film coated by a film of collodion, located within the air-filled 6 inch dry tube of a TRIGA reactor. The collodion layer was varied between 20 and 100 μm thickness, resulting in an 8.8% difference in energy deposition and 12% difference in displacements-per-atom within the Lexan substrate. These findings indicate that collodion adhesive thickness has a moderate impact on …

Uranium Chemical Compound Classification Using Sub-Images And Statistical Machine Learning For Nuclear Forensics, Lee C. Lambert, Brett J. Borghetti, Abigail A. Bickley

Faculty Publications

Uranium particle analysis from Scanning Electron Microscope (SEM) imagery is a crucial tool in nuclear forensics. The particle morphology lexicon proposed by Tamasi et al. in J Radioanal Nucl Chem 307, 1611–1619 (2016) follows a standardized, manual identification process to identify particle morphology features. The present work seeks to mirror this methodology using computer feature selection from the scikit-image Python library rather than human classification. Using a random forest classifier, a 56% overall uranium true positive classification accuracy (a 39.6% balanced classification accuracy) was achieved on a test set outperforming a naïve (chance) model by 48%. The methodology introduced splits …

The Behavior And Complexation Of Technetium Under Conditions Relevant For Nuclear Fuel Reprocessing, Rachel E. Greenberg

Dissertations, Theses, and Capstone Projects

Spent nuclear fuel is reprocessed by utilizing several large-scale solvent extraction processes. One of the most prevalent of these processes is the plutonium uranium reduction extraction (PUREX) process. This process involves an organic phase composed of tributyl phosphate (TBP) in kerosene and an aqueous phase comprised of concentrated nitric acid. Both uranium (U) and plutonium (Pu) are extracted into the organic phase by nitrate and TBP complexation while the various fission products remain in the initial aqueous phase. Pu is then chemically reduced to its trivalent state and back-extracted into a second aqueous phase, thereby separating the two fissile materials. …

A Study On The Great Comet Of 2024: C/2023 A3 (Tsuchinshan–Atlas) Via Radio Interferometry, Jesse Bier, Nathan X. Roth

Undergraduate Research Symposium

Our solar system is approximately 4.5 billion years old. Comets are remnants of its formation, serving as time capsules to give us an understanding of its natal heritage. Revealing our own solar system’s history allows us to gain insights into other young stellar systems and the potential for life elsewhere. C/2023 A3 (Tsuchinshan–ATLAS) was a comet from the Oort cloud on its first and possibly only journey to the inner solar system. The comet grew in brightness until it was brighter than Venus on October 9^th, 2024, making it temporarily brighter than Venus and one of the brightest …

Development Of Mixed O/S-Donor Imidazole Thione Ligands For Trivalent Lanthanide/Actinide Separations, Rhianna Wolsleger

All Dissertations

Separation of lanthanides and actinides is difficult due to their very similar size and charge. Increasing selectivity for actinides over lanthanides is possible by incorporating a softer, more polarizable donor atom into a chelating ligand, since the softer donor atom is capable of greater orbital overlap with the 5f orbitals of the actinides vs the 4f orbitals of the lanthanides. Sulfur-containing imidazole thione chelating ligands have not been investigated for this purpose but possess a resonance structure that puts significant negative charge on the sulfur, enabling it to form strong metal-sulfur bonds compared to other sulfur-containing ligands such as thioethers …

Intrinsic Gas-Phase Behavior Of Uranium Species: A Comprehensive Reactivity Study Of [O=U≡Ch]+ And [Uh]+, Justin Terhorst

Electronic Theses and Dissertations

The intrinsic chemistry of actinide elements, particularly uranium, remains a key challenge in understanding f-block reactivity due to the complexity introduced by solvent interactions, counter-ions, and complex equilibria in the condensed phase. In this dissertation, a systematic gas-phase study utilizing preparative tandem ion-trap mass spectrometry (PTMSⁿ) is presented, focusing on the reactivity of uranium-centered species, specifically [OUCH]⁺, an oxy uranium methylidyne species, and [UH]⁺ ions. By stripping away solvent effects and isolating the ions, PTMSⁿ provides a powerful platform to probe the fundamental chemical behavior of uranium species in their intrinsic state.

The …

Analysis Of Dense Metals Accumulation In Shikaripara Stone Mines, Gopinath Gorai, Nirajan Kumar Mandal

Makara Journal of Science

This study aimed to measure the amount of dangerous substances in the cultivated area of the Shikaripara stone mines in Jharkhand, India, which are well known for their stone quarrying. Sixteen soil samples were collected at varying dis-tances from the Shikaripara stone mines in the Dumka District of Jharkhand. The metals found in these samples in-clude Pb, As, Zn, Mn, Cd, Cu, Fg, and Fe. The combined amount of the elements was calculated by inductively coupled plasma mass spectrometry. Enrichment factor, accumulation index, contamination factor, pollution load index (PLI), Nemerow index, and ecological risk index (RI) were employed to assess …

Uranium(Vi) & Thorium(Iv) Speciation In Organic Media Containing Organophosphorus & Diglycolamide Extractants, Joel Castillo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Developing sustainable green energy systems is a continually growing concern as the world is faced with urgent issues of climate change and global warming. Nuclear energy provides one of the most efficient solutions to supplying power to the electrical grid without causing more carbon pollution. There are nearly a hundred thousand metric tons of used nuclear fuel (UNF) stored on-site at decommissioned nuclear power plants for an indefinite period of time. Achieving a finalized closed fuel cycle is a crucial part in developing the nuclear energy necessary for combating the issues of pollution and greener energy. Understanding actinide speciation especially …

Development Of Uranium Fluoride Microstructures, Harry Jang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Uranium microstructured materials with controlled size and shape have found applications in several branches of the nuclear industry including as targets for medical isotopes production, fuels for nuclear reactors, standards for analytical measurements, and energy sources for space exploration. Morphological studies of actinide materials are also highly relevant to nuclear forensics-related work. Other potential applications include information storage, catalysis, sensors, and luminescent devices. Most studies on uranium microstructured materials have focused on binary oxides, nitrides, carbides, and fluorides, with the spherical shape being the dominant morphology. Prior to the work reported in this dissertation, aside from UF4 microspheres (ms) and …

Nuclear Fuel Cycle Chemistry: A Density Functional Study, Eduardo Montoya

UNLV Theses, Dissertations, Professional Papers, and Capstones

The nuclear fuel cycle aptly describes the life cycle of nuclear fuel sources such as uranium. From its early forms in naturally bearing ores, to its high-temperature sintering into a fuel pellet, the chemistry uranium experiences throughout the fuel cycle is diverse, driving many experimental efforts towards understanding its chemistry to both improve nuclear technologies and advance the safety and handling of nuclear materials. Computing techniques and methodologies can be used to supplement experimental research and are readily available to researchers interested in utilizing computing-based data to support experimental findings. Density functional theory (DFT) is commonly practiced, reliably predicting the …

44ti/44sc Generator Development And Radiolabeling Optimization For Medical Applications, Christine E. Schmidt-Kennelty

Dissertations, Theses, and Capstone Projects

In recent years, there has been a growing interest in scandium-44 (⁴⁴Sc) for medical applications due to its favorable decay properties. With a relatively short half-life of 3.97 hours and high positron branching ratio of 94.3%, ⁴⁴Sc is an ideal candidate for positron emission tomography (PET) imaging. However, producing ⁴⁴Sc without an on-site cyclotron limits access, as its short half-life makes it impractical to ship to more remote locations.

To address this issue, ⁴⁴Ti/⁴⁴Sc generators have become a focal point of research, providing an onsite source of⁴⁴Sc. Despite their potential, current …

Extraction Of Neutron-Gamma Irradiated Diffusion Pump Oils, Cooper L. Tillman

All Theses

This work successfully demonstrates solvent extraction methods for separation of oil from the by-products when two commercially available vacuum pump oils were exposed to an intense neutron and gamma-ray radiation environment. Nuclear fusion power at a commercial scale has accelerated the need for radiation resistant vacuum technology, such as oil-based diffusion pumps. Polyphenyl ether and aromatic silicone oils were irradiated at the Rhode Island Nuclear Science Center (RINSC) up to MGy absorbed doses with neutron and gamma-ray radiation. Solvent extractions were performed using hexane and isopropanol to characterize the oil extraction as a function of total absorbed dose. The by-products …

Positron Emission Tomography In Oncology And Environmental Science, Samantha Delaney

Dissertations, Theses, and Capstone Projects

The last half century has played witness to the onset of molecular imaging for the clinical assessment of physiological targets. While several medical imaging modalities allow for the visualization of the functional and anatomical properties of humans and living systems, few offer accurate quantitation and the ability to detect biochemical processes with low-administered drug mass doses. This limits how physicians and scientists may diagnose and treat medical issues, such as cancer, disease, and foreign agents.

A promising alternative to extant invasive procedures and suboptimal imaging modalities to assess the nature of a biological environment is the use of positron emission …

Photoelectic Driven Decomposition Of Uracil Via Hard X-Ray Irradiation, Trimaan Malik

UNLV Theses, Dissertations, Professional Papers, and Capstones

Radiation damage into biological samples creates substantial challenges across a wide range of fields, from biochemistry to materials science. This comprehensive study investigates the effects of x-ray irradiation on uracil, the only nucleobase exclusive to Ribonucleic acid (RNA), to understand how doping with 10% (by mass) of specific powdered elements impacts the sustained radiation damage. The experiments were conducted at the Brockhouse Undulator Beamline of the Canadian Light Source synchrotron. Virgin and doped uracil samples were irradiated with hard x-rays, above their respective absorption edges, and studied with x-ray diffraction to compare their decomposition behaviors. The Uracil reflections on the …

Assessment Of Mucin 13 (Muc13) As An Imaging Target For Guiding Colorectal Cancer Treatment: A Pathway Towards Theranostic Development, Ryan P. Coll, Aiko Yamaguchi, Jianbo Wang, Xiaoxia Wen, Denise Hernandez, Subhash C. Chauhan, H. Charles Manning

Research Symposium

Background: A theranostic strategy combining diagnostic imaging and targeted therapy in a single regimen is proposed for improved management and treatment of colorectal cancer (CRC). Increased specificity in detection by the noninvasive imaging technique positron emission tomography (PET) can be achieved by radiolabeling antibodies (Abs) designed to target tumor-associated antigens with increased expression post-translational modifications present in cancer cells. In this study, an Ab designed to target the transmembrane glycoprotein mucin 13 (MUC13) was radiolabeled with the positron-emitting radionuclide zirconium-89 (⁸⁹Zr) for PET imaging of a xenograft mouse model of CRC. Specified uptake of this radioimmunoconjugate was observed …

Synthesis Of Bis-Thioacid Derivatives Of Diarylethene And Their Photochromic Properties, Pramod Aryal, Jonathan Bietsch, Gowri Sankar Grandhi, Richard Chen, Surya B. Adhikari, Ephraiem S. Sarabamoun, Joshua J. Choi, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Diarylethenes (DAEs) are an important class of photoswitchable compounds that typically undergo reversible photochemical conversions between the open and closed cyclized forms upon treatment with UV light or visible light. In this study, we introduced thioacid functional groups to several photochromic dithienylethene (DTE) derivatives and established a method that can be used to prepare these photoswitchable thioacids. Four thioacid-functionalized diarylethene derivatives were synthesized through the activation of carboxylic acids with N-hydroxysuccinimide, followed by reactions with sodium hydrosulfide with yields over 90%. These derivatives exhibited reversible photoswitching and photochromic properties upon treatment with ultraviolet (UV) and visible lights. The thioacid groups …

Compton Scattering Of Mammographic Soft X-Ray Beams By Alkali And Transition Metal Salt Filters Produce X-Ray Interference Zones That May Have Treatment Potential For Localized Cancer Lesions, Subhendra N. Sarkar, Eric Lobel, Sabina Rakhmatova, Derbie Desir, Somdat Kissoon, Daler Djuraev, Katie Tam

Publications and Research

In breast x-ray imaging scattered radiation adds 50% of harmful radiation dose from anisotropic Compton scattering mechanism. We have been working with double layered inorganic salt materials that can induce Compton scattering to the incident mammographic x ray beams (in 20-30 kVp range) with adequate isotropy (angular control). Typically metal nitrates and alkali halide salt layers are shown here to cause low energy radiation interference zones with high and low photon intensities and local flux heterogeneity in terms of flux covariance. Spatial variation of low energy photon flux creates concentrated and sparse radiation zones that may be used to induce …

Celestial Bodies, Rebecca L. Rand, Mark Popinchalk

Capstones

Most of us will never come close to touching space. But space touches us every day. On Celestial Bodies, journalist Rebecca Rand and astronomer Mark Popinchalk explore the ways outer space interacts with life on earth.

In Episode 1, hosts Rebecca Rand and Mark Popinchalk explore how, for millions of years, trees have been recording celestial events in space. Within the rings of their trunks, trees store radiation from solar flares, supernovae, and changes in the earth’s magnetic field. The hosts talk to Dr. Ben Pope to learn more about what we can discover by looking at radioactive molecules …

Actinide Behavior In Soft Ligand Environments And Higher Oxidation States Of Neptunium In Aqueous Media With Solid-State Synthesis Of Np(Vii) Compounds, Kelly Floyd Seeley

UNLV Theses, Dissertations, Professional Papers, and Capstones

The fundamental properties of Uranium and Neptunium were investigated with Powder X-Ray Diffraction (PXRD) to study the behavior or 5f electrons with chalcogen, alkali metals, and alkaline earth metals. Two novel compounds were generated: NaCuUS₃ and NaCuNpS₃. There are several crystal structures that form in the family of AMM’Q (A = s-block, M = d-block, M’ = d-block or f-block, and Q = chalcogen), with oxidation states of A¹⁺, M¹⁺, M’⁴⁺, and Q^2- ions from the family of type I compounds. Work was continued to …

The High Pressure Dependence Of X-Ray Induced Decomposition Of Cadmium Oxalate, Adrian F. Lua Sanchez, Petrika Cifligu, Marc Graff, Michael Pravica, Pradip K. Bhowmik, Changyong Park, Egor Evlyukhin

Physics & Astronomy Faculty Research

The high proclivity of x rays to destabilize and distort molecular structures has been previously utilized in the synthesis of novel compounds. Here, we show that x-ray induced decomposition of cadmium oxalate induces chemical and structural transformations only at 0.5 and 1 GPa. Using x-ray diffraction and Raman spectroscopy, the synthesized product is identified as cadmium carbonate with cadmium oxalate remnants, which is stable under ambient conditions. At ambient and >1 GPa pressures, only degradation of the electronic density distribution is observed. The transformation kinetics are examined in terms of Avrami’s model, which demonstrates that despite the necessity of high …

Corrosion Related To The Nuclear Waste Containers, Ali Ebrahimzadeh Pilehrood

Corrosion Research

The disposal of nuclear waste is a demanding topic, and the existing methods, whether it is temporary storage in spent fuel pools or storage in geological repositories, both face the risk of corrosion-related problems. Any failure in these storage methods can potentially lead to the release of radioactive materials into the environment. To avert such catastrophic scenarios, people in the nuclear industry consistently monitor and maintain these storage facilities endlessly and attempt to improve the plans designed to store nuclear waste. Here, I will examine the nuclear waste management organization (NWMO) plan in Canada. Choosing an appropriate location for the …

Women As A Force Multiplier For Bringing Nuclear Forensic Capabilities To The International Stage, Heather M. Dion, Caterina Fox, Kim Knight, Anne Phillip

International Journal of Nuclear Security

In 2009, the US Department of Energy National Nuclear Security Administration’s (NNSA’s) Defense Nuclear Nonproliferation Program initiated a new nuclear forensics outreach effort under its Confidence Building Measures Program. Little did they know that the timing could not have been better. This article focuses on the early years (2009–2015) of the NNSA’s international nuclear forensics outreach, specifically the efforts and experiences of the women who helped establish this program, building it from a fledgling, bilateral effort into an enduring technical capacity provider engaging with dozens of countries and multilateral organizations. At the onset of the program, nuclear forensics was an …

The Development Of Novel Radioscandium And Hydroxypyridinonate Based Radiopharmaceuticals, Michael Phipps

Dissertations, Theses, and Capstone Projects

The use of radiometals in radiopharmaceutical development has drastically increased over the last decade, owed in part to the diverse chemistry and emission characteristics of the radiometals, which allow chemists to create a toolbox of agents to better tailor patient care. Challenges with the use of radiometals include the selection of the metal and the development of optimized chelators to cover the diverse chemistry of the metals which make up the majority of the periodic table. Scandium is the first transition metal and has multiple radioisotopes whose emission characteristics have potential application in medicine. 3,4,3-LI(1,2-HOPO) is a chelator whose denticity, …

Separation Of Zr From Complex Matrices For Isotope Harvesting Applications, Jake A. Bence

Dissertations, Theses, and Capstone Projects

Zr isotopes have various applications in nuclear science, such as ⁸⁶Zr and ⁸⁹Zr in nuclear medicine, ⁸⁸Zr as a diagnostic isotope relevant to stockpile stewardship, and the fission product ⁹⁵Zr useful as an s-process branch nucleus for study in astrophysics. To access these isotopes of interest, dedicated production methods and subsequent processing chemistry are required. Direct production routes can be technically challenging and difficult to obtain enough activity to meet demand. The processing chemistry of Zr isotopes is tedious due to the tendency for Zr to hydrolyze in solution without highly acidic conditions or a strong …

The Development Of Novel Radioimmunoconjugates For The Pet Imaging And Radioimmunotherapy Of Cancer, Samantha M. Sarrett

Dissertations, Theses, and Capstone Projects

Antibodies have long played a vital role in nuclear medicine for both the diagnosis and therapy of various malignancies. The role and development of antibodies in nuclear medicine can be broadly separated into three different categories: 1) bioconjugation strategies, 2) immunoPET imaging, and 3) radioimmunotherapy. This dissertation will attempt to comprehensively cover each of these categories through a series of studies, protocols, and reviews. For the bioconjugation strategies, we will describe the development of a novel site-selective bioconjugation strategy using an innovative lysine-targeting reagent, PFP-bisN₃, to prepare [⁸⁹Zr]Zr-^SSKDFO-pertuzumab for visualizing HER2+ breast cancer. Further, …

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …

Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris

All Theses

Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 10⁵ and 2.14 x10⁶ years (Hu, 2010). Considering these characteristics, ⁹⁹Tc and ²³⁷Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …

Development Of Optical Nanomaterial For Enhanced Cerenkov Imaging, Qize Zhang

Dissertations, Theses, and Capstone Projects

Cancer is a significant public health problem worldwide and is the second leading cause of death in the United States. Imaging has increasingly been used over the last two decades to improve the diagnosis and guidance of tumor tissue removal surgery. Among the most widely used techniques for in vivo imaging are planar and tomographic fluorescence imaging and bioluminescence imaging. Despite their utility, these techniques are primarily restricted to preclinical use. Factors that have prevented translation from the bench to the bedside include depth-penetration considerations, regulatory issues, and toxicity. A recent development in nuclear imaging has been the ability to …