Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “toxicity”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Environmentally-Friendly Fixatives with Embedded Intelligence for Dust Management at Contaminated Sites – 21266

Wind or rain can potentially spread loose hazardous contaminants from piles of rubble and soil waiting to be trucked to a landfill site for disposal. Water, which is plentiful near remediation sites, is the traditional dust suppressant during demolition, post-demolition sizing and encapsulation as well as soil trucking activities. However, water can mobilize the toxic metal contaminants in the soil into the ground water. Ground water is highly regulated and contaminant removal is costly. InnoSense LLC (ISL) is developing DustSafe™ as a cost-effective alternative to water for various decontamination & decommissioning (D&D) applications. It is a sprayable dust abatement solution designed to actively trap, remediate, and aid in visualizing hazardous materials while preventing their dispersion by wind, water or impact. Aside from application as a dust suppressant to trap airborne toxic and radiological hazards during demolition activities, with customization DustSafe can be used to locate/characterize and remediate hazards prior to D&D activities.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Bioconversion of Thermochemical Intermediates

Thermochemical (TC) biofuels production via both pyrolysis and hydrothermal liquefaction produces aqueous waste streams, typically with organic compounds at concentrations of -50-100 g/L. These streams represent a wastewater treatment cost and carbon loss for the TC biorefinery, but the concentration range for these compounds is ideal for bioconversion. To that end, the Bioconversion of Thermochemical Intermediates (BTI) project is developing advanced analytics and engineered microbes to convert these waste streams to co-products, with the overall aim of improving the economics and carbon conversion efficiency of TC biorefining. To date, we have primarily focused on development of advanced analytical chemistry approaches to fully characterize TC aqueous streams and engineering of Pseudomonas putida for conversion of non-conventional substrates, including methylated phenolics, cyclic ketones, furans, and C1-C3 light oxygenates, into atom-efficient products. Two primary challenges are the rapid deployment of aqueous-compatible analytics to changing upstream conditions and dealing with the toxicity of the feed streams to engineered microbes. The project efforts have resulted in engineered strains of P. putida able to consume 90% of the organic compounds in aqueous waste streams from catalytic fast pyrolysis, more than 300-fold toxicity tolerance improvements in P. putida, and carbon closures exceeding 90% for TC wastewater streams across multiple processing technologies.

BASIC BIOLOGICAL SCIENCES,BIOMASS FUELS↗
DOE OSTI2022

Biological Lignin Valorization

Given lignin's heterogeneity, catalytic depolymerization results in aromatic compound mixtures, and conversion of this complex substrate to a single product is challenging. To that end, the Biological Lignin Valorization (BLV) project is pursuing biological funneling, wherein aromatic catabolic microbes are engineered to convert a mixture of lignin-derived compounds to a single product. Namely, we employ Pseudomonas putida and pursue atom-efficient products, such as muconic acid, which can be further converted to direct replacements or used in performance-advantaged bioproducts. Overall, biological lignin conversion can make major contributions to reduce the minimum fuel selling price of the integrated biorefinery. Early industrial efforts in this area are also leading to value-added products, including in collaboration with the BLV project. Primary challenges associated with BLV efforts include accessing bio-available monomers from lignin (with the Lignin Utilization project), enabling commercial titers, rates, and yields of bioproducts from lignin-derived compounds, and overcoming substrate and product toxicity. To date, we have 1) demonstrated 49 g/L of muconate from aromatic compounds and 4 g/L of muconate from lignin, 2) improved the toxicity tolerance of P. putida to key aromatic substrates, 3) debottlenecked biological funneling for higher rates, and 4) engineered P. putida to convert S, G, and H-type lignin-derived compounds to a single product.

BIOMASS FUELS,INORGANIC, ORGANIC, PHYSICAL, AND AN↗
DOE OSTI2023

Functional Predictor Variables for the Leaching Potential of Arsenic and Selenium from Coal Fly Ash

The release of leachates from intact coal ash impoundments is a concern due to the enrichment and mobilization of toxic elements such as arsenic (As) and selenium (Se). This study aims to explore the intrinsic properties of coal fly ash that correlate with the relative leachability of As and Se. We performed leaching experiments with 52 fly ash samples collected from 15 different U.S. power plants and representing coal feedstocks from the three major domestic regions. We assessed the mobilization potential of As and Se in fly ash based on standardized leaching protocols and performed multivariate and lasso regression analyses to explore correlations of leachable As and Se contents with characteristics such as major element contents, loss on ignition, and pH. The results of regression models indicated that major elements (Fe, Ca, and Al) for a wide range of fly ashes can serve as predictor variables for the leaching potential of As but not for Se. LOI and pH were not important predictive variables in the models. Both regression approaches resulted in relatively strong fits for leachable As (correlation coefficient R 2 = 0.78 for both models) compared to models for leachable Se (R 2 = 0.49). Overall, these results suggest that correlation models combined with on-site elemental analysis with portable analyzers may enable a screening method for leachable As in coal ash.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2020

Countermeasures for Preventing and Treating Opioid Overdose

The only medication available currently to prevent and treat opioid overdose (naloxone) was approved by the US Food and Drug Administration (FDA) nearly 50 years ago. Due to its pharmacokinetic and pharmacodynamic properties, naloxone has limited utility under some conditions and would not be effective to counteract mass casualties involving large-scale deployment of weaponized synthetic opioids. To address shortcomings of current medical countermeasures for opioid toxicity, a trans-agency scientific meeting was convened by the US National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH) on August 6 and 7, 2019, to explore emerging alternative approaches for treating opioid overdose in the event of weaponization of synthetic opioids. The meeting was initiated by the Chemical Countermeasures Research Program (CCRP), was organized by NIAID, and was a collaboration with the National Institute on Drug Abuse/NIH (NIDA/NIH), the FDA, the Defense Threat Reduction Agency (DTRA), and the Biomedical Advanced Research and Development Authority (BARDA). This paper provides an overview of several presentations at that meeting that discussed emerging new approaches for treating opioid overdose, including the following: (1) intranasal nalmefene, a competitive, reversible opioid receptor antagonist with a longer duration of action than naloxone; (2) methocinnamox, a novel opioid receptor antagonist; (3) covalent naloxone nanoparticles; (4) serotonin (5-HT)1A receptor agonists; (5) fentanyl-binding cyclodextrin scaffolds; (6) detoxifying biomimetic “nanosponge” decoy receptors; and (7) antibody-based strategies. These approaches could also be applied to treat opioid use disorder.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Toward Validation of Toxicological Interpretation of Diffusive Gradients in Thin Films in Marine Waters Impacted by Copper

Determination of Mytilus galloprovincialis larvae median effect concentration (EC50), of Cu in coastal marine waters by diffusive gradient in thin-films (DGT), has been shown to effectively reduce the need to consider dissolved organic carbon (DOC) concentration and quality. West coast marine and estuarine organisms’ chronic toxicity test protocol was used to validate previously modelled protective effects, afforded to highly sensitive marine larvae by ligand competition, in five diverse site waters. The results demonstrate significant narrowing of toxicological endpoints, where EC50s ranged from 3.74 – 6.67 µg/L as CDGT Cu versus 8.76 – 26.8 µg/L as CuDISS over a DOC range of 0.74 – 3.11 mg/L. Additionally, DOC quality (characterized by fluorescence excitation and emission matrices) indicates that the heterogeneity of competing Cu binding ligands, in common marine waters, minimizes the need for class determinations toward explaining the degree of protection, when assumptions in criterion maximum concentration (CMC) setting are conservative. A CDGT Cu EC50 of 3.7 µg/L, and corresponding CMC CDGT Cu of 1.8 µg/L, for universal application by regulatory compliance-monitoring programs, are proposed as a superior approach toward both integration of dynamic water quality over effective exposure periods and quantification of biologically-relevant trace Cu speciation and are demonstrated by in situ data.

Diffusive Gradients in Thin-films, copper, seawate↗
DOE OSTI2019

Synthesis and anticancer effects of conjugates of doxorubicin and unsaturated fatty acids (LNA and DHA)

Doxorubicin (DOX) is a leading cytostatic drug with many adverse effects in use. We are still looking for methods that will allow us to preserve the therapeutic effect against the tumor cells and reduce the toxicity to the normal cells. In our work, we obtained amide derivatives of DOX by reaction of the amino group with α-linolenic (LNA) and docosahexaenoic (DHA) acids (2, 3), as well as double-substituted derivatives via amide and ester linkages (4, 5). The structures of the compounds were confirmed by Proton Nuclear Magnetic Resonance (1H NMR), Carbon-13 Nuclear Magnetic Resonance (13C NMR), and High Resolution Mass Spectrometry (HRMS) analyses. For all compounds 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the cytotoxic effect on human cancer cell lines (SW480, SW620, and PC3) and Chinese hamster lung fibroblasts (V79) that were used as a control. The cytotoxic activity was established by calculation of the inhibitory concentration IC{sub 50}. In addition, a cytotoxic capacity against tumor cells for tested compounds was expressed as a selectivity factor (selectivity index, SI). Lactate dehydrogenase (LDH) assay was performed for all compounds to assess the level of cell damage. To explain the basic mechanism of cell death induction the Annexin V-FITC/IP flow cytometry analysis was investigated. We found that all studied conjugates exhibit lower cytotoxicity but higher selectivity than DOX. Among the all derivatives, the conjugates formed by the amide and ester linkages (4, 5) were found to be more promising compared with conjugates (2, 3) formed only by the amide linkage. They show high cytotoxicity toward the tumor cell lines and moderate cytotoxicity towards the normal cell line.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Cancer Treatment-Associated Pericardial Disease: Epidemiology, Clinical Presentation, Diagnosis, and Management

Purpose of Review: Cancer therapeutics have seen tremendous growth in the last decade and have been effective in the treatment of several cancer types. However, with advanced therapies like kinase inhibitors and immunotherapies, there have been unintended consequences of cardiotoxicities. While traditional chemotherapy and radiation-induced cardiotoxicity have been well studied, further research is needed to understand the adverse effects of newer regimens. Recent Findings: Both immune-mediated and non-immune-medicated cytotoxicity have been noted with targeted therapies such as tyrosine kinase inhibitors and immune checkpoint inhibitors. In this manuscript, we describe the pericardial syndromes associated with cancer therapies and propose management strategies. Pericardial effusion and pericarditis are common presentations in cancer patients and often difficult to diagnose. Concomitant myocarditis may also present with pericardial toxicity, especially with immunotherapies. In addition to proper history and physical, additional testing such as cardiovascular imaging and tissue histology need to be obtained as appropriate. Holding the offending oncology drug, and institution of anti-inflammatory medications, and immunosuppressants such as steroids are indicated. Summary: A high index of suspicion, use of standardized definitions, and comprehensive evaluation are needed for early identification, appropriate treatment, and better outcomes for patients with cancer treatment-associated pericardial disease. Further research is needed to understand the pathophysiology and to evaluate how the management of pericardial conditions in these patients differ from traditional management and also evaluate new therapies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2024

A survey study on arsenic speciation in coal fly ash and insights into the role of coal combustion conditions

Coal fly ashes (CFAs) are the low-density byproducts of the coal combustion process. Improper or uncontrolled CFA disposal poses significant environmental and health concerns due to the potential leaching of toxic heavy metals such as arsenic (As). Previous studies have investigated the content and speciation of As in different CFA samples, yet systematic information on As speciation in CFA with representative coal source and combustion conditions is still missing. Based on a recent survey study on the typical coal sources and combustion conditions across the U.S., this study selected 19 representative CFA samples to systematically investigate As speciation and potential correlations with these parameters. The composition, morphology, mineralogy, and As speciation of these CFA samples were characterized by complementary analytical, microscopic, and spectroscopic techniques. Synchrotron X-ray spectroscopy and microscopy analyses revealed the dominant As oxidation state to be As(V) and with strong associations to Ca, with the exception of 3 samples that had 19–51% As(III), likely due to the use of selective catalytic reduction (SCR) process. Principal component analysis was conducted to identify potential correlations of As concentration and oxidation state with parameters such as major element content, loss on ignition (LOI), average particle size, coal source, and combustion condition. Al 2 O 3 and FeO content were found to capture a majority of the variability. Further, results from this study provide fundamental basis for understanding the correlations between coal source, combustion conditions, CFA characteristics, and As speciation, and providing insights for downstream beneficial utilization or disposal management.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2020

Manganese: The overlooked contaminant in the world largest mine tailings dam collapse

Manganese (Mn) is an abundant element in terrestrial and coastal ecosystems and an essential micronutrient in the metabolic processes of plants and animals. Mn is generally not considered a potentially toxic element due to its low content in both soil and water. However, in coastal ecosystems, the Mn dynamic (commonly associated with the Fe cycle) is mostly controlled by redox processes. Here, we assessed the potential contamination of the Rio Doce estuary (SE Brazil) by Mn after the world’s largest mine tailings dam collapse, potentially resulting in chronic exposure to local wildlife and humans. Estuarine soils, water, and fish were collected and analyzed seven days after the arrival of the tailings in 2015 and again two years after the dam collapse in 2017. Using a suite of solid-phase analyses including X-ray absorption spectroscopy and sequential extractions, our results indicated that a large quantity of Mn II arrived in the estuary in 2015 bound to Fe oxyhydroxides. Over time, dissolved Mn and Fe were released from soils when Fe III oxyhydroxides underwent reductive dissolution. Due to seasonal redox oscillations, both Fe and Mn were then re-oxidized to Fe III , Mn III , and Mn IV and re-precipitated as poorly crystalline Fe oxyhydroxides and poorly crystalline Mn oxides. In 2017, redox conditions (Eh: -47 ± 83 mV; pH: 6.7 ± 0.5) favorable to both Fe and Mn reduction led to an increase (~880%) of dissolved Mn (average for 2015: 66 ± 130 μg L -1 ; 2017: 582 ± 626 μg L -1 ) in water and a decrease (~75%, 2015: 547 ± 498 mg kg -1 ; 2017: 135 ± 80 mg kg -1 ) in the total Mn content in soils. The crystalline Fe oxyhydroxides content significantly decreased while the fraction of poorly ordered Fe oxides increased in the soils limiting the role of Fe in Mn retention. The high concentration of dissolved Mn found within the estuary two years after the arrival of mine tailings indicates a possible chronic contamination scenario, which is supported by the high levels of Mn in two species of fish living in the estuary. Our work suggests a high risk to estuarine biota and human health due to the rapid Fe and Mn biogeochemical dynamic within the impacted estuary.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Organs at Risk Considerations for Thoracic Stereotactic Body Radiation Therapy: What Is Safe for Lung Parenchyma?

Stereotactic body radiation therapy (SBRT) has become the standard of care for inoperable early-stage non-small cell lung cancer and is often used for recurrent lung cancer and pulmonary metastases. Radiation-induced lung toxicity (RILT), including radiation pneumonitis and pulmonary fibrosis, is a major concern for which it is important to understand dosimetric and clinical predictors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Potentiating Antitumor Efficacy Through Radiation and Sustained Intratumoral Delivery of Anti-CD40 and Anti-PDL1

Mounting evidence demonstrates that combining radiation therapy (RT) with immunotherapy can reduce tumor burden in a subset of patients. However, conventional systemic delivery of immunotherapeutics is often associated with significant adverse effects, which force treatment cessation. The aim of this study was to investigate a minimally invasive therapeutics delivery approach to improve clinical response while attenuating toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Single- and Multifraction Stereotactic Radiosurgery Dose/Volume Tolerances of the Brain

As part of the American Association of Physicists in Medicine Working Group on Stereotactic Body Radiotherapy investigating normal tissue complication probability (NTCP) after hypofractionated radiation therapy, data from published reports (PubMed indexed 1995-2018) were pooled to identify dosimetric and clinical predictors of radiation-induced brain toxicity after single-fraction stereotactic radiosurgery (SRS) or fractionated stereotactic radiosurgery (fSRS).

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Conformal Avoidance of Normal Organs at Risk by Perfusion-Modulated Dose Sculpting in Tumor Single-Dose Radiation Therapy

Although 24 Gy single-dose radiation therapy (SDRT) renders >90% 5-year local relapse-free survival in human solid tumor lesions, SDRT delivery is not feasible in ∼50% of oligometastatic lesions owing to interference by dose/volume constraints of a serial organ at risk (OAR). Conformal OAR avoidance is based on a hypothetical model positing that the recently described SDRT biology specifically permits volumetric subdivision of the SDRT dose, such that high-intensity vascular drivers of SDRT lethality, generated within a major tumor subvolume exposed to a high 24 Gy dose (high-dose planning target volume [PTV{sub HD]}), would equilibrate SDRT signaling intensity throughout the tumor interstitial space, rendering bystander radiosensitization of a minor subvolume (perfusion-modulated dose sculpting PTV [PTV{sub PMDS}]), dose-sculpted to meet a serial OAR dose/volume constraint. An engineered PTV{sub PMDS} may thus yield tumor ablation despite PMDS dose reduction and conformally avoiding OAR exposure to a toxic dose.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Normal Tissue Response of Combined Temporal and Spatial Fractionation in Proton Minibeam Radiation Therapy

Proton minibeam radiation therapy, a spatial fractionation concept, widens the therapeutic window. By reducing normal tissue toxicities, it allows a temporally fractionated regime with high daily doses. However, an array shift between daily fractions can affect the tissue-sparing effect by decreasing the total peak-to-valley dose ratio. Therefore, combining temporal fractions with spatial fractionation raises questions about the impact of daily applied dose modulations, reirradiation accuracies, and total dose modulations.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Safety Margins for the Delineation of the Left Anterior Descending Artery in Patients Treated for Breast Cancer

Cardiac toxicity after breast cancer (BC) radiation therapy is partly due to the large radiation doses to coronary arteries. The left anterior descending artery (LAD) is particularly exposed. A first step in achieving robust dose constraints to the LAD during treatment planning is homogeneous delineation based on guidelines. LAD delineation can be problematic due to heart movements. The aim of the study was to establish a safety margin for delineation of the LAD in patients with BC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

A Phase 1 Dose Escalation Study of Neoadjuvant SBRT Plus Elective Nodal Radiation with Concurrent Capecitabine for Resectable Pancreatic Cancer

The role of neoadjuvant radiation for resectable pancreatic adenocarcinoma is controversial. We performed a prospective dose-escalation study of neoadjuvant stereotactic body radiation therapy (SBRT) with concurrent capecitabine and elective nodal irradiation (ENI) followed by surgical resection to explore the toxicity and feasibility of this approach.

62 RADIOLOGY AND NUCLEAR MEDICINE↗