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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.

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All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

EVT 16s Data and Large Supplementary Files

Soil microorganisms often interact to carry out decomposition of complex organic carbon and nitrogen compounds, such as chitin, but the high diversity and complexity of the soil microbiome and habitat has posed a challenge to elucidating such interactions between soil microorganisms. Here, we seek to address this challenge through analysis of a model soil consortium (MSC-2) of eight soil bacterial species. Our aim was to elucidate specific roles of the member species during chitin metabolism. Samples were collected from MSC-2 incubated in chitin-enriched soil over three months. Multi-omics was used to understand how the community composition, transcripts, proteins and chitin decomposition shifted over time. The data clearly and consistently revealed a temporal shift during chitin decomposition with defined contributions by individual species. A Streptomyces genus member (sp001905665) was a key player in early steps of chitin decomposition, with other MSC-2 members being central in carrying out later steps. These results illustrate how multi-omics applied to a defined consortium untangles interactions between soil microorganisms.

McClure, Ryan [Pacific Northwest National Laborato↗
DOE OSTI2019

Endovascular Thrombectomy for Acute Ischemic Stroke

Purpose of Review: To review the current evidence supporting the use of endovascular thrombectomy (EVT) for the treatment of acute ischemic stroke (AIS) due to anterior circulation large vessel occlusion (LVO). Recent Findings: Recent advances in AIS management by EVT have led to significant reduction in morbidity and mortality in selected patients with LVO within the anterior circulation. Until recently, use of EVT was strictly based on time criteria, within 4.5 to 12 h of symptom onset with many patients presenting with “wake-up” stroke who were not considered for EVT. The positive results of the DAWN and DEFUSE-3 trials have shown benefit in extending the therapeutic window for EVT to 24 and 16 h, respectively, after last known normal (LKN) time in the setting of large ischemic penumbra. These trials represent a paradigm shift in contemporary treatment of AIS, changing from a purely time-based decision to treat to an individualized decision based on clinical and radiographic findings of salvageable tissue. Summary: Overall, acute stroke management has evolved considerably over the years from intravenous thrombolysis to include EVT, with paralleled improvements in patient selection and thrombectomy devices. Since the results of the DAWN and DEFUSE-3, EVT is now considered the standard of care in select patients with anterior circulation LVO up to 24 h from LKN time. Despite these developments, post-stroke disability remains pervasive and further studies are warranted in establishing the role of EVT in posterior circulation and distal vessel occlusions, with need for development of new and effective techniques for revascularization of small vessels.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

The blocking of aquaporin-3 (AQP3) impairs extravillous trophoblast cell migration

Highlights: • AQP1, AQP3 and AQP9 are expressed in the extravillous trophoblast cell line, Swan 71. • CuSO{sub 4}, a potent inhibitor of AQP3, significantly reduced Swan 71 cell migration. • AQP3 silencing significantly attenuates Swan 71 cell migration. • AQP3 participates in extravillous trophoblast cell migration. Several aquaporins (AQPs) are expressed in extravillous (EVT) and villous trophoblast cells. Among them, AQP3 is the most abundant AQP expressed in chorionic villi samples from first trimester, followed by AQP1 and AQP9. Although AQP3 expression persists in term placentas, it is significantly decreased in placentas from preeclamptic pregnancies. AQP3 is involved in the migration of different cell types, however its role in human placenta is still unknown. Here, we evaluated the role of AQP3 in the migration of EVT cells during early gestation. Our results showed that Swan 71 cells expressed AQP1, AQP3 and AQP9 but only the blocking of AQP3 by CuSO{sub 4} or the silencing of its expression by siRNA significantly attenuates EVT cell migration. Our work provides evidence that AQP3 is required for EVT cell migration and suggests that an altered expression of placental AQP3 may produce failures in placentation such as in preeclampsia.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Periprocedural Heparin During Endovascular Treatment of Tandem Lesions in Patients with Acute Ischemic Stroke: A Propensity Score Analysis from TITAN Registry

Background and Purpose: Data on safety and efficacy of periprocedural use of heparin are limited during treatment of acute ischemic stroke patients with anterior circulation tandem occlusion. This study aimed to investigate the impact of heparin use during endovascular therapy of anterior circulation tandem occlusions on the functional and safety outcomes. Methods: A retrospective analysis of the multicenter observational TITAN registry was performed. Patients with anterior circulation tandem occlusion and treated with endovascular therapy (EVT) were included, with or without extracranial carotid intervention. We divided patients into two groups based on periprocedural heparin use (heparin vs. non-heparin). The dose of intravenous unfractionated heparin ranged from 1500 to 2500 I.U. Primary study endpoint was 90-day Modified Rankin Scale (mRS). Secondary study endpoint included angiographic and safety endpoints such as hemorrhagic complications. A propensity-score-matched analysis was performed. Results: Among 369 patients, heparin was used in 68 patients (18.4%). In the propensity-score-matched cohort, favorable outcome (mRS 0–2) occurred in 51.3% in heparin group and 58.0% in non-heparin group (matched OR, 0.76; 95% CI, 0.32–1.78; P = 0.52). Similar result was found in propensity-score-adjusted cohort (adjusted OR, 0.72; 95%CI, 0.39–1.32; P = 0.28). Likewise, there was no difference in the rate of successful reperfusion (mTICI 2b-3) (propensity-score-adjusted OR, 1.03; 95%CI, 0.50–2.09; P = 0.93) neither in safety endpoints between the two groups. Conclusions: Periprocedural heparin use during EVT of anterior circulation tandem occlusions was not associated with better functional, angiographic or safety outcomes. These findings are applicable for low doses of heparin, and further studies are warranted.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2024

Extreme Risk Mitigation in Reinforcement Learning using Extreme Value Theory

Risk-sensitive reinforcement learning (RL) has garnered significant attention in recent years due to the growing interest in deploying RL agents in real-world scenarios. A critical aspect of risk awareness involves modelling highly rare risk events (rewards) that could potentially lead to catastrophic outcomes. These infrequent occurrences present a formidable challenge for data-driven methods aiming to capture such risky events accurately. While risk-aware RL techniques do exist, they suffer from high variance estimation due to the inherent data scarcity. Our work proposes to enhance the resilience of RL agents when faced with very rare and risky events by focusing on refining the predictions of the extreme values predicted by the state-action value distribution. To achieve this, we formulate the extreme values of the state-action value function distribution as parameterized distributions, drawing inspiration from the principles of extreme value theory (EVT). We propose an extreme value theory based actor-critic approach, namely, Extreme Valued Actor-Critic (EVAC) which effectively addresses the issue of infrequent occurrence by leveraging EVT-based parameterization. Importantly, we theoretically demonstrate the advantages of employing these parameterized distributions in contrast to other risk-averse algorithms. Our evaluations show that the proposed method outperforms other risk averse RL algorithms on a diverse range of benchmark tasks, each encompassing distinct risk scenarios.

Wang, Yu↗