Oak Ridge Institute For Science And Education Research Articles

Cutaneous Radiation Injuries: REAC/TS Clinical Experience.

The Radiation Emergency Assistance Center/Training Site (REAC/TS) is one of the US Department of Energy (DOE)/National Nuclear Security Administration (NNSA) Nuclear Emergency Response Team (NEST) assets and has been responding to radiological incidents since 1976. REAC/TS is in the Oak Ridge Institute for Science and Education (ORISE). A critical part of the REAC/TS mission is to provide emergency response, advice, and consultation on injuries and illnesses caused from ionizing radiation. Fortunately, radiation injuries are not frequent, but when they occur, they are more likely to be cutaneous radiation injuries (CRI) or internal contamination. In this paper, we will review selected cases from the REAC/TS experience in order to illustrate cutaneous patterns of injury and treatment options.

Pseudotemporal and spatial organization of B cell activation and differentiation in Peyer's patches

Abstract Organized lymphoid tissues are important sites of immune induction where B cells activate and differentiate. High-resolution transcriptomic technology has revolutionized current understandings of B cell activation and differentiation in organized lymphoid tissues such as lymph nodes but has not been used to dissect B cell activation and differentiation in Peyer’s patches, important sites of intestinal immune induction. We utilized single-cell RNA sequencing and spatial transcriptomics to define pseudotemporal and spatial organization, respectively, of B cell activation and differentiation in porcine jejunal and ileal Peyer’s patches (JPPs and IPPs). IPPs had greater follicular mass and more defined follicular borders than JPPs, resulting in greater follicular B cell abundance in IPPs and non-follicular B cell abundance in JPPs. Despite follicular morphology and B cell abundances varying between JPPs and IPPs, pseudotemporal trajectories and predicted spatial locations of B cell activation and differentiation were similar between intestinal locations. Transition of resting into follicular B cells was demarcated by increased expression of follicle- and cell cycle-associated genes and movement of cells from interfollicular zones (IFZs) into follicles. Another trajectory indicated transition of resting B cells located in IFZs directly into antibody-secreting cells located in IFZs and crypts, suggesting a route of extrafollicular B cell activation and differentiation. Altogether, results indicate conserved patterns of both follicular and extrafollicular B cell activation and differentiation in Peyer’s patches across intestinal locations, despite differences in cellular abundances and follicular morphology. Research was funded by (1) USDA-ARS CRIS project #5030-3200- 225-00D, (2) the SCINet project of the USDA ARS project number 0500-00093-001- 00-D, and (3) an appointment to the Agricultural Research Service (ARS) Research Participation Program administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664. All opinions expressed in this paper are the authors’ and do not necessarily reflect the policies and views of USDA, ARS, DOE, or ORAU/ORISE.

Investigation of Surface Adsorption and Electrode Passivation during Electrochemical Oxidation of Redox-Active Organics

Redox-active organic molecules (ROMs) have gained interest as electroactive materials for redox flow batteries (RFBs). Electrochemical properties of ROMs, i.e., their solubility and redox potential, can be tuned through molecular engineering of the base molecule. Previously, we reported values of the apparent anodic charge transfer coefficient α (values approaching 1) associated with the electrochemical oxidation of a model ROM, 4-hydroxy-TEMPO.1 Also, we have proposed an adsorption-mediated mechanism to explain this unusual value of α, and have presented evidence to support the occurrence of adsorbed intermediates. Here, we extend this investigation to gain further insights using techniques of slow-scan voltammetry and electrode cycling, and apply them to other ROMs. We will discuss results of spectroscopic and micro-gravimetric studies, which provide further insights into the physicochemical properties of the adsorbed surface-passivating films. Ramifications of these to implementation of ROMs in flow batteries will be discussed too.[1] N. A. Shaheen, M. Ijjada, M. B. Vukmirovic, R. Akolkar. J. Electrochem. Soc., 167 (2020) 143505. Acknowledgements: Investigation of the model ROM was supported by Breakthrough Electrolytes for Energy Storage (BEES)—an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award #DE-SC0019409. Work completed at Argonne was supported by the Joint Center for Energy Storage Research (JCESR), a U.S. Department of Energy, Energy Innovation Hub, and by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education (ORISE) for the DOE. ORISE is managed by ORAU under contract #DE‐SC0014664. All opinions expressed in this paper are the author’s and do not necessarily reflect the policies and views of DOE, ORAU, or ORISE.

Internal contamination cases: The REAC/TS experience

The Radiation Emergency Assistance Center/Training Site or REAC/TS is a United States Department of Energy (DOE) emergency response asset and part of the National Nuclear Security Administration's (NNSA) Nuclear Emergency Support Team (NEST). REAC/TS started in 1976 to provide support to the US DOE and is under the Oak Ridge Institute for Science and Education (ORISE) and operated for the US DOE by Oak Ridge Associated Universities, a consortium of 125+ universities to further science and developing future scientists. As part of the support for the US DOE, REAC/TS is on call 24 hours a day, seven days a week for any radiological/nuclear (R/N) injuries or illnesses in the US and throughout the world. REAC/TS was one of the initial eight World Health Organization (WHO) Collaborating Centers, throughout the world, established in 1980 for radiation emergency management and subsequent member of WHO's Radiation Emergency Management Preparedness and Assistance Network (REMPAN). This article will discuss the REAC/TS experience with more recent internal contamination cases and discuss the many gaps existing in assessing and managing cases of internal contamination.

Landscape Analysis of the Application of Artificial Intelligence and Machine Learning in Regulatory Submissions for Drug Development From 2016 to 2021.

An analysis of regulatory submissions of drug and biological products to the US Food and Drug Administration from 2016 to 2021 demonstrated an increasing number of submissions that included artificial intelligence/machine learning (AI/ML). AI/ML was used to perform a variety of tasks, such as informing drug discovery/repurposing, enhancing clinical trial design elements, dose optimization, enhancing adherence to drug regimen, end-point/biomarker assessment, and postmarketing surveillance. AI/ML is being increasingly explored to facilitate drug development. Over the past decade, there has been a rapid expansion of artificial intelligence/machine learning (AI/ML) applications in biomedical research and therapeutic development. In 2019, Liu et al. provided an overview of how AI/ML was used to support drug development and regulatory submissions to the US Food and Drug Administration (FDA). The authors envisioned that AI/ML would play an increasingly important role in drug development.1 That prediction has now been confirmed by this landscape analysis based on drug and biologic regulatory submissions to the FDA from 2016 to 2021. This analysis was performed by searching for submissions with key terms “machine learning” or “artificial intelligence” in Center for Drug Evaluation and Research (CDER) internal databases for Investigational New Drug applications, New Drug Applications, Abbreviated New Drug Applications, and Biologic License Applications, as well as submissions for Critical Path Innovation Meeting and the Drug Development Tools Program. We evaluated all data from 2016 to 2021. Figure 1a demonstrates that submissions with AI/ML components have increased rapidly in the past few years. In 2016 and 2017, we identified only one such submission each year. From 2017 to 2020, the numbers of submissions increased by approximately twofold to threefold yearly. Then in 2021, the number of submissions increased sharply to 132 (approximately 10-fold as compared with that in 2020). This trend of increasing submissions with AI/ML components is consistent with our expectation based on the observed increasing collaborations between the pharmaceutical and technology industries. Figure 1b illustrates the distributions of these submissions by therapeutic area. Oncology, psychiatry, gastroenterology, and neurology were the disciplines with the most AI/ML–related submissions from 2016 to 2021. Figure 1c summarizes the distributions of these submissions by the stage of therapeutic development life cycle. In these submissions, most of the AI/ML applications happen at the clinical drug development stage, but they also happen at the drug discovery, preclinical drug development, and postmarketing stages. It is important to note that the frequency by which AI/ML is mentioned in regulatory submissions to the FDA likely only represents a fraction of its increasingly widespread use in drug discovery. As demonstrated from this analysis, AI/ML is being utilized across many aspects of the drug development life cycle. AI/ML holds great promise to help improve both the efficiency of drug development and to further inform the understanding of the efficacy and safety of the treatment. There is an increasing trend of AI/ML applications for drug development in recent years, and the authors anticipate that this trend will likely only increase over time. Both opportunities and challenges lie ahead for the potential uses of AI/ML, and pharmaceutical and technology companies are actively investing in this area. Moreover, academic researchers are continuing to investigate current and future applications. The FDA has also been preparing to manage and evaluate AI/ML uses by engaging with a broad set of stakeholders on these issues and building its capacity in these scientific fields, in order to promote responsible innovation in this area. In 2021, the FDA and other regulatory agencies jointly identified 10 guiding principles that can inform the development of Good Machine Learning Practice to help promote safe, effective, and high-quality medical devices that use AI/ML.10 Although these Good Machine Learning Practice guiding principles were developed for medical device development, many of them (e.g., multi-disciplinary collaboration; data quality assurance, data management, and robust cybersecurity practices; representativeness of study participants and data sets; independence of the training and testing data sets) are also applicable to drug development. Liu et al. discussed some expectations for the application of AI/ML in drug development (e.g., fit-for-purpose and risk-based expectations, proper validation, generalizability, explainability, etc.).1 It is important to note that the regulatory considerations for the application of AI/ML in drug development are evolving and will require input from all stakeholders in various disciplines. Effective communication and active collaboration will serve an increasingly important role in fostering innovation, helping to advance regulatory science, and aiding in the promotion and protection of public health in the United States and the world. The authors thank Rajanikanth Madabushi for critical review of the manuscript, and Giang Ho and Kimberly Bergman for their assistance in the production of Figure 2. This work was supported in part by an appointment to the Research Participation Program at the Office of Clinical Pharmacology/Center for Drug Evaluation and Research, US Food and Drug Administration, administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the US Department of Energy and the US Food and Drug Administration. Julie Hsieh and Mo Tiwari were ORISE fellows contributing to this work. No funding was received for this work. The authors declared no competing interests for this work. The contents of this article reflect the views of the authors and should not be construed to represent the FDA's views or policies. No official support or endorsement by the FDA is intended or should be inferred.

Gene signatures for intestinal and peripheral innate lymphoid cells in pigs reveal tissue-specific imprinting and similarities to human cells via single-cell RNA sequencing

Abstract Intestinal innate lymphoid cells (iILCs) impact intestinal health outcomes, but study of iILCs in humans is limited. Human peripheral ILCs (pILCs) are easily obtained but may vary substantially from iILCs, thus requiring comparison of iILCs and pILCs to determine applicability of pILCs as surrogates to study iILC function. Pigs have anatomic, physiological, nutritional, and immune similarities to humans that are lacking in rodent models, making pigs a relevant biomedical model; however, ILCs are poorly defined in pigs. Single-cell RNA sequencing was performed to compare porcine iILCs to pILCs and determine potential similarities of porcine to human ILCs. Porcine pILCs matched porcine natural killer (NK) cell descriptions, while iILCs were annotated as group 1 and group 3 ILCs. Gene modules obtained independent of cell annotations were distilled to core signatures of genes most highly specific to pILCs, pan-iILCs, group 1 iILCs, and group 3 iILCs. The pILC signature included conventional NK cell genes, while the group 3 iILC signature included genes associated with type 3 immunity. Pan-iILC and group 1 iILC signatures included genes associated with tissue residency, cell activation, and metabolism, indicating tissue-specific, activation-associated imprinting. Gene profiles were used to develop in situ iILC detection methods, establishing group 1 iILCs were intraepithelial, while group 3 iILCs resided in lamina propria/gut-associated lymphoid tissue. Findings indicated iILCs were ILC subsets distinct from pILCs, thus opposing pILCs as surrogates to study iILC dynamics. Moreover, gene profiles and in situ locations of iILCs drew close parallels to human iILCs functions, supporting pigs as a biomedical model for iILC research. Research was supported by appropriated funds from USDA-ARS CRIS 5030-31320-004-00D, an appointment to the Agricultural Research Service (ARS) Research Participation Program administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664. All opinions expressed in this paper are the authors’ and do not necessarily reflect the policies and views of USDA, ARS, DOE, or ORAU/ORISE. This research used resources provided by the SCINet project of the USDA ARS project number 0500-00093-001-00-D.

The Ecology Underground coalition: building a collaborative future of belowground ecology and ecologists.

Rising to meet global, interconnected challenges, such as food security and ecosystem resilience to global change, requires insights from across the Earth. This is especially true for belowground terrestrial ecological processes. Soil ecologists have answered this call: like mushrooms, large global datasets and databases on soil physics, chemistry and ecology are sprouting up everywhere (e.g. Fine‐Root Ecology Database (Iversen et al., 2018), FunFun (Zanne et al., 2020), GlobalFungi (Větrovský et al., 2020), COntinuous SOil REspiration (Jian et al., 2020), Global distribution of earthworm diversity (Philips et al., 2019) etc.). It is now time to leverage synergies among these datasets to link the continuum of belowground processes to ecosystem functions (e.g. decomposition, nutrient cycling and soil respiration). Built on interdisciplinary and international collaborations, data synthesis that leads to a holistic understanding is one of the best ways of predicting the future of terrestrial ecosystems and for preserving ecosystem services under global change. In 2020, global interconnectedness was on display as we saw a pandemic sweep across the world in weeks. The pandemic allowed the Ecological Society of America (ESA) to enter a new digital era by holding a fully virtual conference. While technology cannot yet replicate all aspects of an in‐person conference, the virtual platform increased accessibility and reduced the climate impact of the annual conference. It also provided an opportunity for early‐career plant and microbial ecologists from five ESA Organized Oral Sessions and one Inspire Session to organize Ecology Underground, a two‐day program of live virtual talks and open discussions on integrative belowground ecology on 4 and 5 August 2020. Ecology Underground was sponsored by New Phytologist, the ESA Soil Ecology Section, the US Department of Energy, Biological and Environmental Research program and the Oak Ridge Institute for Science and Education (ORISE), and gathered 453 participants over two days. The online platform allowed for participation across the globe (37 countries were represented; Fig. 1) and was an opportunity to think creatively about how scientific discussions and global collaborations can take place, now and in the future. Open in a separate window Fig. 1 The online platform of Ecology Underground allowed for participation across the globe.

Surface Sensitivity of Fluoroethylene Carbonate Breakdown on Lithium Silicide Surfaces

Silicon anodes are a promising material for lithium ion batteries due to their large theoretical capacity for storing lithium. When the battery is charging, the anode works by alloying lithium ions with the silicon anode where the lithium ions are reduced. In addition to the lithium ions being reduced, unwanted side reduction reactions of the electrolyte also occur. When the electrolyte reductively decomposes at the anode surface, a solid-electrolyte interphase (SEI) is formed. Fluoroethylene carbonate (FEC) is added to the electrolyte to make a more robust SEI which prevents further electrolyte decomposition. From FEC reductive decomposition, the primary reduction products are CO2, CH2CHO, and F-. While the decomposition products have been discovered, the lowest energy surface facet which promotes the breakdown of FEC into those products is still unknown. Here FEC and its reduction products are being studied on different lithium silicide surfaces using density functional theory. The lithium silicide phases under consideration are the crystalline LiSi phase with a low lithium concentration and the crystalline Li15Si4 phase with a higher lithium concentration. All unique low index surface facets are considered for each lithium silicide phase. The interactions of FEC and its dissociation products are analyzed on the different anode surface facets to determine the surface sensitivity of FEC breakdown. From the binding energies of the FEC reactant and the CO2, CH2CHO, and F- products on the lithium silicide surface facets, FEC dissociation reaction energies are calculated. The facet on which SEI formation begins to form is determined from the reaction energies for both the low and high concentration lithium silicide anodes. This material is based upon work supported by the U.   S. Department of Energy,   Office of Science, Office of Workforce Development for Teachers and Scientists,   Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education (ORISE) for the DOE. ORISE is managed by ORAU under contract number DE-SC0014664.   Use of the Center for Nanoscale Materials, an Office of Science user facility, is   supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under   contract number   DE-AC02-06CH11357.

Investigation of Conducting Polymers As Binding Agents for Oer/ORR Electrode Characterization

Investigation of the electrochemical performance of catalytic materials for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) has been the topic of intense research due to the different outcomes depending on the preparation of the electrode and the lack of standard characterization techniques to ease the evaluation of diverse materials. Most of the materials studied include perovskites, pyrochlores, spinels, among other structures. Nafion® and Polyvinylidene fluoride (PVDF) binding agents suspended in aqueous solutions and organic solvents, respectively, are widely employed for the characterization of catalyst powder samples. Nafion® is a copolymer with ionic properties due to ion hoping between adjacent sulfonic groups. Typical catalyst supports using Nafion® involve small amounts of Nafion 5%wt diluted in water and alcohols to ensure a homogeneous dispersion [1]. In the case of PVDF, which is a non-reactive thermoplastic polymer, the catalyst powder is mixed with 10 to 20% PVDF, active carbon (acetylene black, AB) and dispersed in n-methyl pyrolidone (NMP). In the latter, AB provides with enough electronic conductivity needed for the electrochemical characterization. Using carbon as a conductive backbone is a very common practice; however several disadvantages arise from its utilization, such as: 1) lack of a reliable method for the determination of real electrochemical surface area, 2) participation of carbon during ORR might overestimate the real performance of the catalyst, and 3) carbonaceous materials tend to oxidize during the oxygen evolution reaction. Therefore, the determination of a binding agent that is capable of providing sufficient electronic conductivity and high chemical and mechanical stability during both OER and ORR can serve as advancement for the investigation of electrochemical properties for the catalytic powder oxides. In the present work, a set of conducting polymers are used as binding agents and compared with Nafion-based supports. The conducting polymers include Polyaniline and poly(9,9-dioctylfluorene-co-fluorenone (PFM) conducting polymers were evaluated as binding agents in alkaline media for OER. Both of these polymers have been evaluated as negative electrode binders for Li-ion batteries, and have shown improved cycleability and high energy density [2]. The catalytic material used for the evaluation was lead ruthenium pyrochlore, Pb2Ru2O7-δ. Preliminary results, (Fig. 1) show it is possible to have an enhanced performance of the pyrochlore by the use of a conducting polymer binder during anodic reactions. The performance for ORR was not greatly influenced by the presence of a conducting polymer binder. A well-defined redox peak ascribed to Ru4+/5+ with high reversibility was observed for PFM support. This peak is also present in the case of Nafion®, but it is only noticeable during the first cycle, and diminishes with further cycling. A systematic study of the influence of the conductive polymer binders on the OER performance in alkaline media will be presented. Figure 1 . Oxygen evolution on lead ruthenium pyrochlore supported in PFM (blue) and Nafion (pink). For comparison, PFM with no catalyst (red) and bare glassy carbon electrode (black) are also presented. Acknowledgements This work is supported by the IGERT-NSF fellowship and partially funded by the US Department of Energy/NETL, Oak Ridge Institute for Science and Education (ORISE) fellowship.

Effect of Substitution in Pb2Ru2O7-δ on the Oxygen Evolution Reaction

The identification of economically feasible and highly efficient materials supporting the oxygen evolution reaction (OER) in alkaline media will constitute a major advancement in a variety of technologies such as water splitting, elctrowinning, fuel cells, and metal-air batteries. OER has proven to be a catalytic dependent electrochemical process, and thus, the catalytic material at the oxygen electrode plays an important role in order to improve the efficiency of such technologies. Numerous research studies have been carried out on the synthesis of new electrode materials in order to reduce the voltage loss associated with the oxygen reactions. Pyrochlores containing ruthenium as the transition metal ion possess high area specific activity [1]. Pyrochlores also demonstrate bifunctional characteristics in organic environments [2]. Among the features that make pyrochlores attractive as oxygen electrodes is the unusual framework containing a high density of oxygen vacancies and their apparent ordering, which is believed to aid in the oxygen anion mobility. However, pyrochlore structures are not as widely studied as perovskite structures, in part due to the few elements that can be substituted in the structure without changing the pyrochlore configuration and preserving the electrochemical performance. Previous reports have shown the effect of partial substitution in lead ruthenium pyrochlores (Pb1-xAxRu1-yByO7-δ, 0<x,y<1) for tuning its electronic properties [3]. Moreover, PbBiRu2O7-δ showed an encouraging performance and negligible capacity loss over 85 cycles in an iron-air battery configuration in strong alkaline media [4].  In the present work, partial substitutions of Pb (La and Bi) and Ru (Fe and Co) were performed and the effect on oxygen evolution in alkaline media was investigated. All pyrochlores were prepared by a combustion method which produced pyrochlore oxides with BET area in the range of 6 to 8 m2/g. The catalyst powders were dispersed in a Nafion containing solution to form a catalyst ink. All the samples were characterized by XRD (for phase analysis), XPS (for valency), and SEM (for surface morphology). The OER electrochemical performance has been investigated by means of quasi-steady state current measurements. In addition, kinetic parameters such as Tafel slope and electrochemical reaction order towards OH- were determined. Tafel slope values range from 47 to 75 mV/dec and reaction order values were near unity for most of the compounds. OER activity of selected compounds is presented in Fig. 1. The OER activity for all other compositions will also be presented. Fig. 1 . OER activity at 0.5mV/s for Pb2Ru2O7-δ, Pb1.8La0.2Ru2O7, and Pb1.5Bi0.5Ru2O7. Acknowledgements This work is supported by the IGERT-NSF fellowship and partially funded by the US Department of Energy/NETL, Oak Ridge Institute for Science and Education (ORISE) fellowship.

Comparison of Pyrochlore and Perovskite Electrodes Towards the Oxygen Evolution in Alkaline Media

The identification of economically feasible and high efficient materials towards the oxygen evolution (OER) and reduction (ORR) reactions in alkaline media will constitute a major advancement in a variety of technologies such as water splitting, elctrowinning, fuel cells and metal-air batteries. OER and ORR have proven to be catalytic dependent electrochemical processes, and thus, the catalytic material at the oxygen electrode plays an important role in the performance of such technologies. Numerous research studies have been carried out on the synthesis of new electrode materials in order to reduce the voltage loss associated with the oxygen reactions. In the present work, a comparison of OER behavior of a group of pyrochlore materials (A2B2O7-δ), and non-noble transition metal perovskites (ABO3) will be presented. The pyrochlore and perovskite structures were synthesized by a facile two-step combustion method yielding high purity phases with crystallite size in the vicinity of 20nm. The synthesized compounds include La1-xCaxFeO3, Pb2Ru2O7, and their substitutions, compared to un-supported RuO2 prepared by thermal decomposition of RuCl3. The catalysts powders were dispersed on a Nafion containing solution to form a catalyst ink [1]. The samples were tested in alkaline media in a traditional three-electrode system under continuous N2purging. Among the characteristics that make pyrochlores attractive for oxygen electrodes, is the unusual framework containing high density of oxygen vacancies and their apparent ordering which is believed to aid in the oxygen anion mobility [2]. Perovskite materials are attractive due to the wide range of substituting elements that can be employed to tune their electrocatalytic properties. All the samples were characterized by XRD for phase analysis, XPS for valency, SEM for surface morphology. The OER electrochemical performance has been investigated by means of steady state current measurements. XRD spectra of selected samples and the OER activity are presented in Figure 1a and 1b, respectively. The effect of dopant concentration on the oxygen evolution activity will be discussed.  Acknowledgements This work is supported by the IGERT-NSF fellowship and partially funded by the US Department of Energy/NETL, Oak Ridge Institute for Science and Education (ORISE) fellowship.

High Performance Environmental Profiling of House Dust to Support Computational Exposure Science

High Performance Environmental Profiling of House Dust to Support Computational Exposure ScienceAbstract Number:2750 Shuang Liang, Peter Egeghy*, Karen Bradham, and Mark Strynar Shuang Liang U.S. EPA Oak Ridge Institute for Science and Education (ORISE) Fellow, United States, E-mail Address: [email protected] Search for more papers by this author , Peter Egeghy* U.S. Environmental Protection Agency, United States, E-mail Address: [email protected] Search for more papers by this author , Karen Bradham U.S. Environmental Protection Agency, United States, E-mail Address: [email protected] Search for more papers by this author , and Mark Strynar U.S. Environmental Protection Agency, United States, E-mail Address: [email protected] Search for more papers by this author AbstractFew chemicals have been sufficiently characterized for potential risks to public health. A desire to increase the pace of risk assessment has led to development of robust modeling approaches for screening of exposure potential to complement emergent toxicity screening efforts. Models that integrate chemical properties, consumer product information, and human behavior are now being used to evaluate the exposure potential of large numbers of chemicals. Measurements of chemicals are necessary to evaluate the reliability of these models, but readily available data exist for only few chemicals, typically those previously identified as a hazard to human health. Non-targeted analysis of environmental samples using high resolution mass spectroscopy allows large numbers of chemicals to be measured. We applied liquid chromatography time-of-flight/mass spectrometry (LC-TOF/MS) methods to rapidly screen dust samples obtained from the American Healthy Homes Survey. We observed 100 – 1000 peaks in each sample. Using chemical property information from EPA’s DSSTox database, we were able tentatively identify many of these chemicals. Comparison with EPA’s Consumer Product Chemical Profiling database enabled linking of dozens of compounds with consumer products. Preliminary analysis found that the majority of the identified compounds were associated with ‘beauty care’ products. High performance environmental profiling of house dust holds great promise for the evaluation and calibration of high-throughput exposure models; moreover, further application of the technique to a wider range of environmental media will facilitate integration of emerging analytical and computational technologies to assess exposure potential on a previously unattainable scale. Disclaimer: The views expressed in presentation are those of the author and do not reflect the views or policies of the United States Environmental Protection Agency.

Electrochemical Studies of Lanthanum Ruthenates Towards the Oxygen Evolution Reaction in Alkaline Media

Among the fundamental challenges for enabling metal-air batteries and fuel cells is the oxygen electrocatalysis at the so called air-cathode. Numerous research work has been carried out on the synthesis of new cathode materials in order to reduce the voltage loss associated with the oxygen reactions. ORR and OER have proven to be catalytic dependent electrochemical processes, and thus, the catalytic material at the oxygen-consuming electrode plays an important role in the performance of such technologies.Current catalysts used for air cathodes can be classified into noble metals and metal alloys, carbons, and transition metal oxides. Platinum and carbonaceous electrodes such as Pt-nanopartices dispersed on graphene have been the primary choice to catalyze the ORR because of their known superior electrocatalytic activity. However, carbonaceous materials are poorly stable anodically and readily decompose to oxidize carbon. On the other hand, the oxygen evolution reaction shows little activity on carbonaceous materials, and hence transition metal oxides and noble transition metal oxides are being studied for these purposes. Lanthanum cobalt oxides [1] and lanthanum nickelates [2] of the form ABO3, have also shown promising catalytic activities and good stability. In the present, the electrochemical performance of ruthenium as B site element is studied. Compared with other platinum group metals, ruthenium has exhibited remarkably oxygen evolution activities in alkaline media [3]. A group of lanthanum ruthenate materials including LaRuO3 and La2RuO5 have been synthesized, characterized and studied for oxygen electrode applications. The ruthenate compounds were synthesized by the well-known Pechini polymerization method. All the samples were characterized by XRD for phase analysis and XPS for valence state determination. For the electrochemical measurements, a traditional three-electrode cell was employed. The working electrode consisted of a modified glassy carbon disk with a catalyst ink. The ink was prepared by mixing a predetermined amount of the catalytic powder with poly(vinylidene fluoride) in a ratio of 80:20 and dispersed in n-methyl-2-pyrrolidinone.Electrochemical performance has been investigated by means of steady state current measurements and cyclic voltammetry. Figure 1 (a) and (b) shows the XRD spectra for the monoclinic La2RuO5 compound and the steady state current measurements for both ruthenates, respectively. The XRD model used is a PANalytical X’Pert Powder diffractometer using Cu kα radiation with a wavelength of 1.54056 Å. Acknowledgements This work is supported by the IGERT-NSF fellowship and partially funded by the US Department of Energy/NETL Oak Ridge Institute for Science and Education (ORISE) fellowship.

Diverse Pyrochlore Materials for Oxygen Reduction and Evolution Reaction in Alkaline Medium

The oxygen reduction and evolution reactions (ORR and OER) have proven to be the limiting factors on the development of rechargeable metal-air batteries. Numerous research work has been carried out on the improvement of cathode technologies in order to reduce the voltage loss associated with the oxygen reactions. ORR and OER have proven to be a catalytic electrochemical process, and thus, the catalytic material in the cathode plays an important role in the performance of such batteries.Current catalysts used for air cathodes can be classified into noble metals and metal alloys, carbons, and transition metal oxides. Platinum and platinum-based electrodes such as Pt-nanopartices dispersed on a carbon support have been the primary choice to catalyze the ORR because of their known superior electrocatalytic activity. Other Pt-based alloys, Pt3M (where M can be Fe, Co among others) have also shown superior ORR activities. Carbonaceous materials have also emerged as an alternative for metal-free electrodes. Some of the best performing carbonaceous materials are vertically aligned nitrogen doped carbon nanotubes (VA-NCNT), nitrogen doped porous carbons and graphenes which have exhibit comparable activity to that of the Pt-based electrodes [1]. However, in order to fully develop the applicability of metal-air batteries, bifunctional electrodes are essential.In the present research, a group of pyrochlore materials, A2B2O7-δOδ, have being synthesized, characterized and studied for bifunctional oxygen electrode applications. Among the characteristics that make pyrochlores attractive for air cathodes, is the unusual framework containing oxygen vacancy ordering. Lanthanum, lead and bismuth-based pyrochlores has been synthesized by the well-known Pechini, solid state, and stearic acid methods.All the samples were characterized by XRD for phase analysis, and electrochemical performance has been investigated by means of cyclic voltammetry. The effect of dopant concentration on the electronic conductivity as well as oxygen activity will be presented. Acknowledgements This work is supported by the IGERT-NSF fellowship and partially funded by the US Dept. of Energy/NETL, Oak Ridge Institute for Science and Education (ORISE) fellowship.

Effect of Doping and Preparation Methods in Solid Electrolyte for Lithium Batteries

Recently, solid electrolytes with reasonable room temperature lithium ionic conductivity are being examined for high energy density batteries with safe operation. Several solid state electrolytes based on sulfides and oxides have been investigated [1]. Among them, Garnet phase materials have shown significant improvement in conductivity [2]. Garnet has cubic and tetragonal phases of which the cubic is high temperature with a high ionic conductivity value of 10-4 S/cm [3]. Several doped compositions have also been reported in order to improve the cubic phase ionic conductivity [4]. LLTO Perovskite system has also been reported for high ionic conductivity value of 10-4 S/cm [5,6]. Currently, we have synthesized a Ti, Cr, Ta doped Li7La3Zr2O12and LLTO by a simple Pechini process to investigate their ionic conductivities.A Pechini method was used to synthesize these compoundsusing nitrate salts, ethylene glycol and citric acid in a 38:36:26 ratio respectively in de-ionized water. The samples were dried in an oven overnight at 120°C and then heat-treated at different temperatures to achieve the desired phases. The optimized product was heat treated at 1000°C for six hours, pelletized and then sintered again at higher temperatures (1200°C) to perform the ionic conductivity measurements using impedance spectroscopy.Samples were characterized by XRD for phase analysis and electrochemical impedance performance has been investigated under varying temperatures and voltages. The effect of doping on the phase transition in LLZO and LLTO will be presented. Figure 1 shows the impedance plot for the Ta doped garnet (Li7La3Zr1.5Ta.0.5O12) at room temperature. Ionic conductivity value of 1.27(x10-4) S/cm has been obtained.Detailed impedance measurements on systematic doping of Ti, Cr, Ta etc. in LLZO and LLTO phases using various sample preparation conditions, various ohmic contacts for the pellets will be discussed.Figure. 1 Impedance plot for Li7La3Zr1.5Ta0.5O12 at room temperature. Acknowledgements This work has been supported by the US Dept. of Energy/NETL, EERE program. FRB acknowledges Oak Ridge Institute for Science and Education (ORISE) fellowship.

Gestational weight gain and child weight status at 5 years of age: differential effects by prepregnancy body mass index status

In 2009, IOM released recommendations for gestational weight gain (GWG) and noted a data gap on associations with long‐term outcomes, specifically child weight. Currently the mediating role of birthweight and heterogeneity by prepregnancy BMI are unclear. We used the nationally representative Early Childhood Longitudinal Study‐Birth Cohort to examine associations between GWG and subsequent child weight measured at 5 y. We used regression and path analysis to examine direct and indirect effects mediated by birthweight. Among underweight, normal, overweight and obese women, respectively, prevalence of excessive GWG (above recommendations) was 26%, 38%, 62% and 53%, and child obesity (BMI ≥ 95th percentile) was 9%, 13%, 19% and 27%. Multivariable logistic regression indicated null associations between inadequate GWG and child obesity for all prepregnancy BMI groups, but a significant association with excessive GWG among only normal [OR 1.8 (95% CI 1.3, 2.5)] and overweight [OR 2.0 (95% CI 1.1, 3.4)] women. Path analysis with child BMI z‐score further indicated that among normal and overweight women the direct effect of GWG was stronger than the indirect effect. Among obese women, there was no significant total effect of GWG. Our findings indicate that IOM GWG recommendations are appropriate in the context of child weight; prevention of excessive GWG may be a strategy to prevent child obesity.Grant Funding Source: Oak Ridge Institute for Science and Education (ORISE)

Uncertainties in 63Ni and 55Fe determinations using liquid scintillation counting methods

The implementation of 63Ni and 55Fe determination methods in an environmental laboratory implies their validation. In this process, the uncertainties related to these methods should be analysed. In this work, the expression of the uncertainty of the results obtained using separation methods followed by liquid scintillation counting is presented. This analysis includes the consideration of uncertainties coming from the different alternatives which these methods use as well as those which are specific to the individual laboratory and the competency of its operators in applying the standard ORISE (Oak Ridge Institute for Science and Education) methods.

High‐Surface‐Area Silica Nanospheres (KCC‐1) with a Fibrous Morphology

We are grateful to the KAUST nano-core laboratory group for their help in analysis of the silica spheres. We also thank Dr. V. Unkefer and Dr. T. McElwee for internal reviewing of the manuscript. Thanks are also due to Dr. J. Thivolle and Dr. L. Veyre of CPE, Lyon (France) for their help in mechanical stability study and surface area measurement, respectively. V.P. also thanks Dr. R. S. Varma for valuable comments on this work and Oak Ridge Institute for Science and Education (ORISE) for support during his stay at the US Environmental Protection Agency (US EPA), Cincinnati.

Survival of children with mosaic Down syndrome

American Journal of Medical Genetics Part AVolume 152A, Issue 3 p. 800-801 Research Letter Survival of children with mosaic Down syndrome†‡ Mikyong Shin, Corresponding Author Mikyong Shin mshin@cdc.gov National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TennesseeNational Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, 1600 Clifton Road, MS E86, Atlanta, GA 30333.Search for more papers by this authorCsaba Siffel, Csaba Siffel National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia Computer Sciences Corporation, Atlanta, GeorgiaSearch for more papers by this authorAdolfo Correa, Adolfo Correa National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GeorgiaSearch for more papers by this author Mikyong Shin, Corresponding Author Mikyong Shin mshin@cdc.gov National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TennesseeNational Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, 1600 Clifton Road, MS E86, Atlanta, GA 30333.Search for more papers by this authorCsaba Siffel, Csaba Siffel National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia Computer Sciences Corporation, Atlanta, GeorgiaSearch for more papers by this authorAdolfo Correa, Adolfo Correa National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GeorgiaSearch for more papers by this author First published: 22 February 2010 https://doi.org/10.1002/ajmg.a.33295Citations: 42 † Presented at: Maternal and Child Health Epidemiology Conference, Atlanta, Georgia, December 10–12, 2008. 35th Annual meeting of The International Clearinghouse for Birth Defects Surveillance and Research, Abano Terme, Italy, September 13–17, 2008. ‡ How to cite this article: Shin M, Siffel C, Correa A. 2010. Survival of children with mosaic Down syndrome. Am J Med Genet Part A 152A:800–801. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume152A, Issue3March 2010Pages 800-801 RelatedInformation