Environmental Cost vs. Health Benefit of Radioisotope Usage in Medicine

This module is developed for implementation in a class that discusses the use of radioisotopes in a biomedical setting. The inspiration is a class I teach (Advanced Biomedical Instrumentation), which covers the use of radioisotopes as tracers in biomedical imaging (scintigraphy, SPECT, PET, etc.). The goal of the module is to go further in depth regarding the environmental impact of the use of radioisotopes (from their generation to their disposal—keeping track of any radioactive byproducts), and compare that to the potential for benefits in the quality and/or quantity of a patient’s life (does using the radioisotopes allow patients to live longer, fuller lives).https://rdw.rowan.edu/oer/1016/thumbnail.jp

The Lost Histories of the Shetayet of Sokar: Contextualizing the Osiris Shaft at Rosetau (Giza) in Archaeological History

The Osiris Shaft is one of many archaeological signatures associated with Egypt’s Giza Plateau, the most well-known of which are the Great Pyramids. However, the role(s) the Osiris Shaft feature played in the religious and daily practices of ancient Egyptians remain(s) unknown. This research seeks to contextualize the Osiris Shaft in Egyptian history to learn more about this feature’s story. In order to achieve this goal, this thesis examines funerary deities associated with Memphis theology and explores archaeological investigations related to the Osiris Shaft, including the work of Dr. Zahi Hawass and investigations by the Giza Mapping Project. Thanks to modern technology, archaeological discoveries in Egypt are advancing at an exponential rate, and opportunities to solve some of the mysteries associated with the Osiris Shaft (e.g., its original date of construction) are now emerging. After analyzing existing archaeological evidence in tandem with the evolution and transformation of funerary deities leading up to/synonymous with Osiris, the Osiris Shaft may represent the successor of the Shetayet of Sokar

Incorporating project uncertainty in novel environmental biotechnologies: illustrated using phytoremediation

"Pollution of the environment by metals and organic contaminants is an intractable global problem, with cleanup costs running into billions of dollars using current engineering technologies. The availability of alternative, cheap and effective technologies would significantly improve the prospects of cleaning-up metal contaminated sites. Phytoremediation has been proposed as an economical and ‘green' method of exploiting plants to extract or degrade the contaminants in the soil. To date, the majority of phytoremediation efforts have been directed at leaping the biological, biochemical and agronomic hurdles to deliver a working technology, with scant attention to the economic outlook other than simple estimates of the cost advantages of phytoremediation over other techniques. In this paper we use a deterministic actuarial model to show that uncertainty in project success (the possibility that full clean up may not be realized) may significantly increase the perceived costs of remediation works for decision-makers." Authors' Abstractbiotechnology, Soil contaminants, Environmental remediation Economic aspects, Industrial crop technologies,

Using High-Powered, Frequency-Narrowed Lasers For Rb/129Xe and Cs/129Xe Spin-Exchange Optical Pumping To Achieve Improved Production of Highly Spin-Polarized Xenon For Use In Magnetic Resonance Applications

Nuclear magnetic resonance (NMR) spectroscopy has been extensively used to investigate numerous systems of interest, ranging from collections of molecules to living organisms. However, NMR suffers from one key drawback: an inherent lack of detection sensitivity, as compared to other common forms of spectroscopy. This is due to the minute nuclear magnetic moments and low nuclear spin polarization levels at thermal equilibrium (~10-5 to 10-6), and thus necessitates the use of relatively large sample volumes. One way to overcome this low detection sensitivity is to introduce a species with highly non-equilibrium nuclear spin polarization, such as `hyperpolarized\u27 xenon-129. Hyperpolarized xenon can either be used as its own chemical sensor (due to its exquisitely sensitive chemical shift range), or the non-equilibrium polarization may be transferred from xenon to another molecule of interest (such as a protein or inclusion complex). Hyperpolarized xenon is produced through a process known as spin-exchange optical pumping (SEOP), where the angular momentum from resonant, circularly-polarized light is transferred to the electronic spins of an alkali-metal, and is subsequently transferred to the xenon nuclei through gas-phase collisions. While SEOP has been extensively characterized throughout the years, new experimental techniques and emerging technologies have considerably advanced the field in recent years, and may enable a new understanding of the underlying physics of the system. The first five chapters in this dissertation review background information and the principal motivations for this work. Chapter one reviews the basics of NMR, from the various components of the nuclear spin Hamiltonian and different spin-relaxation pathways to the reasons behind the low polarization of nuclear spins at thermal equilibrium and a few alternative methods to `boost\u27 the NMR signal. Chapter two discusses the fundamental aspects of SEOP, including the electronic spin polarization of the alkali-metal, polarization transfer to the xenon nuclei, and different avenues for the spin polarization to be depleted. The third chapter covers the practical considerations of SEOP from the viewpoint of an experimentalist; namely, the experimental differences when using a variety of alkali metals and noble gases, as well as different SEOP apparatuses and experimental parameters. Chapter four details a variety of different light sources that may be used for SEOP; specifically, the use of laser diode arrays (LDAs) are reviewed, including LDAs that have been frequency-narrowed for more efficient light absorption by the alkali metal. The fifth background chapter covers a variety of magnetic resonance applications of hyperpolarized xenon, including molecular biosensors, specific and non-specific binding with proteins, materials studies, and in vivo applications. The sixth chapter is used as an overview of the dissertation research, which is presented in chapters seven through eleven. Chapter seven details the arrangement of the particular SEOP apparatus used in this research, as well as the experimental protocol for producing hyperpolarized xenon. The eighth chapter accounts the implementation and characterization of the first frequency-narrowed LDA used in this research, as well as an equal comparison to a traditional broadband LDA. Chapter nine introduces the use of in situ low-field NMR polarimetry, which was used to distinguish an anomalous dependence of the optimal OP cell temperature on the in-cell xenon density; the low-field set-up is also used to examine the build-up of nuclear spin polarization in the OP cell as it occurs. The tenth chapter covers the use of high power, frequency-narrowed light sources that are spectrally tunable independent of laser power; this allows for the study of changes to the optimal spectral offset as a function of in-cell xenon density, OP cell temperature, and laser power. Xenon polarization build-up curves are also studied to determine if the spectral offset of the laser affects the nuclear spin polarization dynamics within the OP cell. Finally, chapter eleven accounts the use of high power, broadband LDAs to perform SEOP in which cesium is used as the alkali metal; these results demonstrate (for the first time) that the xenon polarization generated by cesium optical pumping can surpass that of rubidium OP under conditions of high laser flux and elevated in-cell xenon densities

Reconversion of Parahydrogen Gas in Surfactant-Coated Glass NMR Tubes

The application of parahydrogen gas to enhance the magnetic resonance signals of a diversity of chemical species has increased substantially in the last decade. Parahydrogen is prepared by lowering the temperature of hydrogen gas in the presence of a catalyst; this enriches the para spin isomer beyond its normal abundance of 25% at thermal equilibrium. Indeed, parahydrogen fractions that approach unity can be attained at sufficiently low temperatures. Once enriched, the gas will revert to its normal isomeric ratio over the course of hours or days, depending on the surface chemistry of the storage container. Although parahydrogen enjoys long lifetimes when stored in aluminum cylinders, the reconversion rate is significantly faster in glass containers due to the prevalence of paramagnetic impurities that are present within the glass. This accelerated reconversion is especially relevant for nuclear magnetic resonance (NMR) applications due to the use of glass sample tubes. The work presented here investigates how the parahydrogen reconversion rate is affected by surfactant coatings on the inside surface of valved borosilicate glass NMR sample tubes. Raman spectroscopy was used to monitor changes to the ratio of the (J: 0 → 2) vs. (J: 1 → 3) transitions that are indicative of the para and ortho spin isomers, respectively. Nine different silane and siloxane-based surfactants of varying size and branching structures were examined, and most increased the parahydrogen reconversion time by 1.5×–2× compared with equivalent sample tubes that were not treated with surfactant. This includes expanding the pH2 reconversion time from 280 min in a control sample to 625 min when the same tube is coated with (3-Glycidoxypropyl)trimethoxysilane

“I am just like everyone else, except for a nine-digit number”: A Thematic Analysis of the Experiences of DREAMers

This qualitative thematic analysis study explored the experiences of DREAMers, undocumented students raised in the US awaiting the passage of the DREAM Act. We used a phenomenologically-informed textual analysis which resulted in a summary essence of the experience of DREAMers, describing how even though DREAMers are like other contributing members of society “except for a nine-digit number,” certain characteristics make their experience unique. Two websites containing experiences of individuals identifying as DREAMers as they wait for the passage of the DREAM Act, were analyzed to draw out specific themes that represented DREAMers’ experiences. Results revealed the following themes, Uncertainty about the Future, Resilience in Spite of Barriers, Education as a Form of Identity and Empowerment, the Influence of Time, Family Sacrifices for a Better Life, Disconnect from their Countries of Origin, the Meaning of “Undocumented,” and “Collective Survival.” These were summarized in a description of the essence of the phenomenon. These themes suggest implications for researchers and mental health professionals working with this population and highlight the significance of the unique experiences of DREAMers

Using Raman Spectroscopy to Improve Hyperpolarized Noble Gas Production for Clinical Lung Imaging Techniques

Spin-exchange optical pumping (SEOP) can be used to “hyperpolarize” 129Xe for human lung MRI. SEOP involves transfer of angular momentum from light to an alkali metal (Rb) vapor, and then onto 129Xe nuclear spins during collisions; collisions between excited Rb and N2 ensure that incident optical energy is nonradiatively converted into heat. However, because variables that govern SEOP are temperature-dependent, the excess heat can complicate efforts to maximize spin polarization—particularly at high laser fluxes and xenon densities. Ultra-low frequency Raman spectroscopy may be used to perform in situ gas temperature measurements to investigate the interplay of energy thermalization and SEOP dynamics. Experimental configurations include an “orthogonal” pump-and-probe design and a newer “inline” design (with source and detector on the same axis) that has provided a >20-fold improvement in SNR. The relationship between 129Xe polarization and the spatiotemporal distribution of N2 rotational temperatures has been investigated as a function of incident laser flux, exterior cell temperature, and gas composition. Significantly elevated gas temperatures have been observed—hundreds of degrees hotter than exterior cell surfaces—and variances with position and time can indicate underlying energy transport, convection, and Rb mass-transport processes that, if not controlled, can negatively impact 129Xe hyperpolarization