Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Pa”

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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Pa3Al by Materials Project

Pa3Al is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded to eight Pa and four equivalent Al atoms to form PaPa8Al4 cuboctahedra that share corners with twelve equivalent PaPa8Al4 cuboctahedra, edges with eight equivalent AlPa12 cuboctahedra, edges with sixteen PaPa8Al4 cuboctahedra, faces with four equivalent AlPa12 cuboctahedra, and faces with fourteen PaPa8Al4 cuboctahedra. All Pa–Pa bond lengths are 3.19 Å. All Pa–Al bond lengths are 3.19 Å. In the second Pa site, Pa is bonded to eight equivalent Pa and four equivalent Al atoms to form PaPa8Al4 cuboctahedra that share corners with four equivalent PaPa8Al4 cuboctahedra, corners with eight equivalent AlPa12 cuboctahedra, edges with twenty-four PaPa8Al4 cuboctahedra, faces with six equivalent AlPa12 cuboctahedra, and faces with twelve PaPa8Al4 cuboctahedra. All Pa–Al bond lengths are 3.19 Å. Al is bonded to twelve Pa atoms to form AlPa12 cuboctahedra that share corners with four equivalent AlPa12 cuboctahedra, corners with eight equivalent PaPa8Al4 cuboctahedra, edges with eight equivalent AlPa12 cuboctahedra, edges with sixteen equivalent PaPa8Al4 cuboctahedra, faces with four equivalent AlPa12 cuboctahedra, and faces with fourteen PaPa8Al4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3Tl by Materials Project

Pa3Tl is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded to eight Pa and four equivalent Tl atoms to form PaPa8Tl4 cuboctahedra that share corners with twelve equivalent PaPa8Tl4 cuboctahedra, edges with eight equivalent TlPa12 cuboctahedra, edges with sixteen PaPa8Tl4 cuboctahedra, faces with four equivalent TlPa12 cuboctahedra, and faces with fourteen PaPa8Tl4 cuboctahedra. There are four shorter (3.29 Å) and four longer (3.30 Å) Pa–Pa bond lengths. All Pa–Tl bond lengths are 3.30 Å. In the second Pa site, Pa is bonded to eight equivalent Pa and four equivalent Tl atoms to form PaPa8Tl4 cuboctahedra that share corners with four equivalent PaPa8Tl4 cuboctahedra, corners with eight equivalent TlPa12 cuboctahedra, edges with twenty-four PaPa8Tl4 cuboctahedra, faces with six equivalent TlPa12 cuboctahedra, and faces with twelve PaPa8Tl4 cuboctahedra. All Pa–Tl bond lengths are 3.29 Å. Tl is bonded to twelve Pa atoms to form TlPa12 cuboctahedra that share corners with four equivalent TlPa12 cuboctahedra, corners with eight equivalent PaPa8Tl4 cuboctahedra, edges with eight equivalent TlPa12 cuboctahedra, edges with sixteen equivalent PaPa8Tl4 cuboctahedra, faces with four equivalent TlPa12 cuboctahedra, and faces with fourteen PaPa8Tl4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3W by Materials Project

Pa3W is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded to eight Pa and four equivalent W atoms to form distorted PaPa8W4 cuboctahedra that share corners with twelve equivalent PaPa8W4 cuboctahedra, edges with eight equivalent PaPa8W4 cuboctahedra, edges with eight equivalent WPa12 cuboctahedra, faces with four equivalent WPa12 cuboctahedra, and faces with ten equivalent PaPa8W4 cuboctahedra. There are four shorter (3.02 Å) and four longer (3.28 Å) Pa–Pa bond lengths. All Pa–W bond lengths are 3.28 Å. In the second Pa site, Pa is bonded in a square co-planar geometry to eight equivalent Pa and four equivalent W atoms. All Pa–W bond lengths are 3.02 Å. W is bonded to twelve Pa atoms to form WPa12 cuboctahedra that share corners with four equivalent WPa12 cuboctahedra, edges with eight equivalent WPa12 cuboctahedra, edges with sixteen equivalent PaPa8W4 cuboctahedra, faces with four equivalent WPa12 cuboctahedra, and faces with eight equivalent PaPa8W4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3Re by Materials Project

Pa3Re is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Pa and four equivalent Re atoms to form a mixture of distorted corner, edge, and face-sharing PaPa4Re4 tetrahedra. All Pa–Pa bond lengths are 3.05 Å. All Pa–Re bond lengths are 3.05 Å. In the second Pa site, Pa is bonded in a 8-coordinate geometry to eight equivalent Pa and six equivalent Re atoms. All Pa–Re bond lengths are 3.53 Å. Re is bonded in a distorted body-centered cubic geometry to fourteen Pa atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpPa3 by Materials Project

NpPa3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np is bonded to twelve Pa atoms to form NpPa12 cuboctahedra that share corners with four equivalent NpPa12 cuboctahedra, corners with eight equivalent PaNp4Pa8 cuboctahedra, edges with eight equivalent NpPa12 cuboctahedra, edges with sixteen equivalent PaNp4Pa8 cuboctahedra, faces with four equivalent NpPa12 cuboctahedra, and faces with fourteen PaNp4Pa8 cuboctahedra. There are four shorter (3.06 Å) and eight longer (3.29 Å) Np–Pa bond lengths. There are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Np and eight Pa atoms to form PaNp4Pa8 cuboctahedra that share corners with twelve equivalent PaNp4Pa8 cuboctahedra, edges with eight equivalent NpPa12 cuboctahedra, edges with sixteen PaNp4Pa8 cuboctahedra, faces with four equivalent NpPa12 cuboctahedra, and faces with fourteen PaNp4Pa8 cuboctahedra. There are four shorter (3.06 Å) and four longer (3.29 Å) Pa–Pa bond lengths. In the second Pa site, Pa is bonded to four equivalent Np and eight equivalent Pa atoms to form distorted PaNp4Pa8 cuboctahedra that share corners with four equivalent PaNp4Pa8 cuboctahedra, corners with eight equivalent NpPa12 cuboctahedra, edges with twenty-four PaNp4Pa8 cuboctahedra, faces with six equivalent NpPa12 cuboctahedra, and faces with twelve PaNp4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrPa3 by Materials Project

SrPa3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr is bonded to twelve Pa atoms to form SrPa12 cuboctahedra that share corners with four equivalent SrPa12 cuboctahedra, corners with eight equivalent PaSr4Pa8 cuboctahedra, edges with eight equivalent SrPa12 cuboctahedra, edges with sixteen equivalent PaSr4Pa8 cuboctahedra, faces with four equivalent SrPa12 cuboctahedra, and faces with fourteen PaSr4Pa8 cuboctahedra. There are eight shorter (3.37 Å) and four longer (3.39 Å) Sr–Pa bond lengths. There are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Sr and eight Pa atoms to form distorted PaSr4Pa8 cuboctahedra that share corners with twelve equivalent PaSr4Pa8 cuboctahedra, edges with eight equivalent SrPa12 cuboctahedra, edges with sixteen PaSr4Pa8 cuboctahedra, faces with four equivalent SrPa12 cuboctahedra, and faces with fourteen PaSr4Pa8 cuboctahedra. There are four shorter (3.37 Å) and four longer (3.39 Å) Pa–Pa bond lengths. In the second Pa site, Pa is bonded to four equivalent Sr and eight equivalent Pa atoms to form distorted PaSr4Pa8 cuboctahedra that share corners with four equivalent PaSr4Pa8 cuboctahedra, corners with eight equivalent SrPa12 cuboctahedra, edges with twenty-four PaSr4Pa8 cuboctahedra, faces with six equivalent SrPa12 cuboctahedra, and faces with twelve PaSr4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuPa3 by Materials Project

PuPa3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pu is bonded to twelve Pa atoms to form PuPa12 cuboctahedra that share corners with four equivalent PuPa12 cuboctahedra, corners with eight equivalent PaPu4Pa8 cuboctahedra, edges with eight equivalent PuPa12 cuboctahedra, edges with sixteen equivalent PaPu4Pa8 cuboctahedra, faces with four equivalent PuPa12 cuboctahedra, and faces with fourteen PaPu4Pa8 cuboctahedra. There are four shorter (3.20 Å) and eight longer (3.22 Å) Pu–Pa bond lengths. There are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Pu and eight Pa atoms to form PaPu4Pa8 cuboctahedra that share corners with twelve equivalent PaPu4Pa8 cuboctahedra, edges with eight equivalent PuPa12 cuboctahedra, edges with sixteen PaPu4Pa8 cuboctahedra, faces with four equivalent PuPa12 cuboctahedra, and faces with fourteen PaPu4Pa8 cuboctahedra. There are four shorter (3.20 Å) and four longer (3.22 Å) Pa–Pa bond lengths. In the second Pa site, Pa is bonded to four equivalent Pu and eight equivalent Pa atoms to form PaPu4Pa8 cuboctahedra that share corners with four equivalent PaPu4Pa8 cuboctahedra, corners with eight equivalent PuPa12 cuboctahedra, edges with twenty-four PaPu4Pa8 cuboctahedra, faces with six equivalent PuPa12 cuboctahedra, and faces with twelve PaPu4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Optimization of peptide amphiphile-lipid raft interaction by changing peptide amphiphile lipophilicity

Various peptide amphiphile (PA) molecules have been developed to promote bone regeneration. Previously we discovered that a peptide amphiphile with a palmitic acid tail (C 16 ) attenuates the signaling threshold of leucine-rich amelogenin peptide (LRAP)-mediated Wnt activation by increasing membrane lipid raft mobility. In the current study, we found that treatment of murine ST2 cells with an inhibitor (Nystatin) or Caveolin-1-specific siRNA abolishes the effect of C 16 PA, indicating that Caveolin-mediated endocytosis is required. Here, to determine whether hydrophobicity of the PA tail plays a role in its signaling effect, we modified the length of the tail (C 12 , C 16 and C 22 ) or composition (cholesterol). While shortening the tail (C 12 ) decreased the signaling effect, lengthening the tail (C 22 ) had no prominent effect. On the other hand, the cholesterol PA displayed a similar function as the C 16 PA at the same concentration of 0.001% w/v. Interestingly, a higher concentration of C 16 PA (0.005%) is cytotoxic while cholesterol PA at the higher concentration (0.005%) is well-tolerated by cells. Use of the cholesterol PA at 0.005% enabled a further reduction of the signaling threshold of LRAP to 0.20 nM, compared to 0.25 nM at 0.001%. Caveolin-mediated endocytosis is also required for cholesterol PA, as evidenced by Caveolin-1 siRNA knockdown experiments. We further demonstrated that the noted effects of cholesterol PA are also observed in human bone marrow mesenchymal stem cells (BMMSCs). Taken together, these results indicate that the cholesterol PA modulates lipid raft/caveolar dynamics, thereby increasing receptor sensitivity for activation of canonical Wnt signaling.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Annihilating Actinic Photochemistry of the Pyruvate Anion by One and Two Water Molecules

Photochemical behaviors of pyruvic acid in multiple phases have been extensively studied, while those of its conjugate base, the pyruvate anion (CH 3 COCOO – , PA – ) are less understood and remain contradictory in gaseous versus aqueous phases. Here in this article, we report a joint experimental and theoretical study combining cryogenic, wavelength-resolved negative ion photoelectron spectroscopy (NIPES) and high-level quantum chemical computations to investigate PA – actinic photochemistry and its dependence on microsolvation in the gas phase. PA – ·nH 2 O (n = 0–5) clusters were generated and characterized, with their low-lying isomers identified. NIPES conducted at multiple wavelengths across the PA – actinic regime revealed the PA – photochemistry extremely sensitive to its hydration extent. While bare PA – anions exhibit active photoinduced dissociations that generate the acetyl (CH 3 CO – ), methide (CH 3 – ) anions, their corresponding radicals, and slow electrons, one single attached water molecule results in significant suppression with a subsequent second water being able to completely block all dissociation pathways, effectively annihilating all PA – photochemical reactivities. Further, the underlying dissociation mechanisms of PA – ·nH 2 O (n = 0–2) clusters are proposed involving nπ* excitation, dehydration, decarboxylation, and further CO loss. Since the photoexcited dihydrate does not have sufficient energy to overcome the full dehydration barrier before PA – could fragmentate, the PA – dissociation pathway is completely blocked, with the energy most likely released via loss of one water and internal electronic and vibrational relaxations. The insight unraveled in this work provides a much-needed critical link to connect the seemingly conflicting PA – actinic chemistry between the gas and condensed phases.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Mg16PaAl12 by Materials Project

Mg16PaAl12 is gamma-brass-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are five inequivalent Mg sites. In the first Mg site, Mg is bonded in a 10-coordinate geometry to three equivalent Mg, one Pa, and twelve Al atoms. All Mg–Mg bond lengths are 3.18 Å. The Mg–Pa bond length is 3.29 Å. There are a spread of Mg–Al bond distances ranging from 3.16–3.24 Å. In the second Mg site, Mg is bonded in a 3-coordinate geometry to one Pa and five Al atoms. The Mg–Pa bond length is 3.61 Å. There are a spread of Mg–Al bond distances ranging from 2.85–3.23 Å. In the third Mg site, Mg is bonded in a 11-coordinate geometry to one Mg and six Al atoms. There are a spread of Mg–Al bond distances ranging from 3.05–3.13 Å. In the fourth Mg site, Mg is bonded in a 6-coordinate geometry to one Pa and five Al atoms. The Mg–Pa bond length is 3.14 Å. There are a spread of Mg–Al bond distances ranging from 2.81–3.11 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to four Al atoms. There are a spread of Mg–Al bond distances ranging from 2.97–3.20 Å. Pa is bonded in a 3-coordinate geometry to seven Mg and nine Al atoms. There are three shorter (3.19 Å) and six longer (3.20 Å) Pa–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to six Mg, one Pa, and three Al atoms. There are one shorter (2.66 Å) and two longer (2.75 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. Both Al–Al bond lengths are 2.76 Å. In the third Al site, Al is bonded in a distorted q6 geometry to seven Mg, one Pa, and three Al atoms. There are one shorter (2.72 Å) and one longer (2.77 Å) Al–Al bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Size-Dependent Photon Avalanching in Tm 3+ Doped LiYF 4 Nano, Micro, and Bulk Crystals

Photon avalanche (PA) is a highly nonlinear mode of upconversion that is characterized by 100–1000-fold increase in luminescence intensity upon minute increments of pumping power. The practical realization of numerous possible nano-bio-technology applications utilizing the PA phenomenon will require information on its susceptibility to the material volume and surface. In this report these parameters are investigated via experimental and theoretical PA. The two-color, highly nonlinear PA emission at 475 and 800 nm is clearly observed in bulk single crystal, individual microcrystals, and ensembles of colloidal core and core–shell nanoparticles of LiYF 4 host doped with either 3 or 8% of thulium ions. The properties of PA emission, such as PA nonlinearity, PA gain, PA intensity, and luminescence kinetics in these materials show dependence on crystal volume and surface quenching. Theoretical simulations provide understanding of key physical processes that influence PA performance. Moreover, photon avalanche single beam super-resolution imaging is realized for the first time in 3% Tm 3+ doped LiYF 4 core–shell nanoparticles. The obtained insights and predictions form a solid background for further development and applications of new optimized PA materials.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Carbamoylation as an Effective Tool in the Analysis of the Soman Nerve Agent Marker Pinacolyl Alcohol in Soil Matrices by EI-GC-MS and LC-HRMS

Pinacolyl alcohol (PA) is a Schedule 2 chemical commonly featured in most proficiency tests (PTs) administered by the Organisation for the Prohibition of Chemical Weapons (OPCW) due to its direct as well as forensic link to the nerve agent Soman. Therefore, its detection by Chemical Weapons Convention (CWC) inspection teams during on-site investigations is a strong indicator of the past or latent presence of Soman in the environment. Its small molecular weight (102), early elution time, and poor ionization profile make PA a challenging analyte to detect particularly at low concentrations (∼1–10 μg/g). In this work, 1,1′-carbonyldimidazole (CDI) has been used to effectively modify PA for the first time in two different soil matrices (Virginia type A soil and silt sediment) at two separate concentrations (1 and 10 μg/g) for its subsequent detection by EI-GC-MS and LC-HRMS methods. For the EI-GC-MS analysis, the PA carbamate derivative (PIC) exhibits improved chromatography relative to PA such as improved peak shape, increased molecular weight (196 for PIC and 102 for PA) and increased retention time (16.9 min for PIC and ∼4.1 min for PA). In addition, the derivatization also improves the detection of PA by LC-HRMS as the PIC product possesses protonation sites (i.e., imidazole ring) relative to none exhibited by PA. More importantly, the carbamoylation proceeds under mild conditions (55 °C, no base) and rapidly (3 h), characteristics that make it an appealing protocol for the analysis of PA during OPCW PTs or real case scenarios particularly in instances where it is present at low concentrations. It is anticipated that the protocol can be applied to the forensic analysis of this important Soman marker in various environmental matrices.

Chemistry↗
DOE OSTI2023

Performance Assessment Maintenance Plan for the Active Low-Level Burial Ground Trenches 31, 34, and 94 at the Hanford Site

This report documents the maintenance plan for the Hanford Site 200 West Area Active Low-Level Burial Ground Trenches 31 and 34 and 200 East Area Active Trench 94 performance assessment (PA). The PA maintenance plan is one of several supporting documents that are compendiums to the active trenches (Trenches 31, 34, and 94) PA as required in DOE O 435.1, Radioactive Waste Management . The PA is documented in DOE/RL-2021-26, Performance Assessment of Active Trenches in 200 East and West Low-Level Burial Grounds at the Hanford Site . This plan follows the requirements and outline specified in the applicable U.S. Department of Energy (DOE) standard used for developing documents supporting DOE-STD-5002-2017, Disposal Authorization Statement and Tank Closure Documentation . This maintenance plan summarizes the following major activities DOE plans to conduct to maintain the Trenches 31, 34, and 94 PA: Monitoring; Research and development; Planned reviews and analyses; Revisions of Trenches 31, 34, and 94 PA. The planned research and development activities relate to evaluating the key assumptions, including evaluating conceptual model assumptions and parameter value assumptions used in the PA. The planned research and development activities include those that are designed to track the release mechanisms for Category 1, Category 3, and uranium billet waste sources, as well as continued characterization and related modeling of the natural environment in the Central Plateau of the Hanford Site. In addition, the planned research and development activities include focused testing and evaluation of engineered and natural materials to reduce the uncertainty in the conceptual models and parameter values used in the PA. All key and secondary issues identified during the review of the PA by the Low-Level Waste Disposal Facility Federal Review Group have been resolved prior to finalization of the PA. There are no outstanding issues.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Materials Data on Pa2Rh2O5 by Materials Project

Pa2Rh2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded in a body-centered cubic geometry to eight equivalent O atoms. All Pa–O bond lengths are 2.60 Å. In the second Pa site, Pa is bonded to twelve O atoms to form PaO12 cuboctahedra that share corners with four equivalent PaO12 cuboctahedra, faces with four equivalent PaO12 cuboctahedra, and faces with eight equivalent RhO5 square pyramids. There are eight shorter (2.70 Å) and four longer (2.85 Å) Pa–O bond lengths. Rh is bonded to five O atoms to form distorted RhO5 square pyramids that share corners with five equivalent RhO5 square pyramids and faces with four equivalent PaO12 cuboctahedra. There are four shorter (2.04 Å) and one longer (2.13 Å) Rh–O bond lengths. There are two inequivalent O sites. In the first O site, O is bonded to four Pa and two equivalent Rh atoms to form a mixture of distorted face, edge, and corner-sharing OPa4Rh2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°. In the second O site, O is bonded to four equivalent Pa and two equivalent Rh atoms to form a mixture of distorted face, edge, and corner-sharing OPa4Rh2 octahedra. The corner-sharing octahedra tilt angles range from 0–58°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho2Pa2O5 by Materials Project

Pa2Ho2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded in a body-centered cubic geometry to eight equivalent O atoms. All Pa–O bond lengths are 2.85 Å. In the second Pa site, Pa is bonded to twelve O atoms to form PaO12 cuboctahedra that share corners with four equivalent PaO12 cuboctahedra, faces with four equivalent PaO12 cuboctahedra, and faces with eight equivalent HoO5 square pyramids. There are eight shorter (2.90 Å) and four longer (3.08 Å) Pa–O bond lengths. Ho is bonded to five O atoms to form HoO5 square pyramids that share corners with five equivalent HoO5 square pyramids and faces with four equivalent PaO12 cuboctahedra. There are one shorter (2.08 Å) and four longer (2.18 Å) Ho–O bond lengths. There are two inequivalent O sites. In the first O site, O is bonded to four Pa and two equivalent Ho atoms to form a mixture of distorted corner, edge, and face-sharing OHo2Pa4 octahedra. The corner-sharing octahedra tilt angles range from 0–65°. In the second O site, O is bonded in a linear geometry to four equivalent Pa and two equivalent Ho atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Src-mediated Tyr353 phosphorylation of IP3R1 promotes its stability and causes apoptosis in palmitic acid-treated hepatocytes

Palmitic acid (PA)-induced hepatocyte apoptosis is critical for the progression of nonalcoholic fatty liver disease (NAFLD). Inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) is an intracellular Ca{sup 2+}-release channel and is involved in PA-induced hepatocyte apoptosis. While the expression of IP3R1 is elevated in patients with NAFLD and in hepatocytes treated with PA, it remains unclear how PA promotes the expression of IP3R1. In present study, our results showed that PA induced mitochondrial dysfunction and apoptosis, which is accompanied with the increase of the IP3R1 expression in hepatic cells. The inhibition of IP3R1 expression using siRNA ameliorated the PA-induced mitochondrial dysfunction. Furthermore, PA enhanced the stability of the IP3R1 protein instead of an increase in its mRNA levels. PA also promoted the phosphorylation of IP3R1 at the Tyr353 site and increased the phosphorylation of src in hepatic cells. Moreover, an inhibitor of src kinase (SU6656) significantly reduced the Tyr353 phosphorylation of IP3R1 and decreased its stability. In addition, SU6656 improved mitochondrial function and reduced apoptosis in hepatocytes. Conclusion: PA promotes the Tyr353 phosphorylation of IP3R1 by activating the src pathway and increasing the protein stability of IP3R1, which consequently results in mitochondrial Ca{sup 2+} overload and mitochondrial dysfunction in hepatic cells. Our results also suggested that inhibition of the src/IP3R1 pathway, such as by SU6656, may be a novel potential therapeutic approach for the treatment of NAFLD.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Comprehensive Physical Activity Assessment During U.S. Army Basic Combat Training

Abstract Alemany, JA, Pierce, JR, Bornstein, DB, Grier, TL, Jones, BH, and Glover, SH. Comprehensive physical activity assessment during U.S. Army Basic Combat Training. J Strength Cond Res 36(12): 3505–3512, 2022—Physical activity (PA) volume, intensity, and qualitative contextual information regarding activity type and loads carried are limited during U.S. Army Basic Combat Training (BCT). The purpose of this study was to characterize daily (05:00–20:00 hours) PA during BCT using a comprehensive approach. During 2 10-week BCT cycles ( n = 40 trainees per cycle), pedometers, accelerometers, and direct observation were used to estimate daily step count, PA volume, and intensity. Physical activity intensity was categorized by metabolic equivalents (METs) such as “sedentary” (1–2 METs), “light” (2–3 METs), “moderate” (3–6 METs), or “vigorous” (≥6 METs). Daily PA data were analyzed longitudinally using linear mixed models, with significance set at p ≤ 0.05. The mean daily step count was 13,459 ± 4,376 steps, and the mean daily accelerometer-assessed PA volume and intensity were as follows: sedentary: 505 ± 98 minutes, light: 190 ± 78 minutes, moderate: 168 ± 51 minutes, and vigorous: 14 ± 14 minutes, with no differences between cycles for all measures ( p > 0.50). Cumulative time on feet (∼50%) and sitting (20–25%) accounted for most daily activity types during both cycles. Trainees, on average, carried between 3 and 9 kg, and ≥9 kg, for 60% and 10% of the monitored day, respectively. Basic Combat Training's physical demands are high, where trainees achieved 1.7 to 2.7 times greater daily ambulation and 6 times the recommended weekly moderate-to-vigorous PA compared with civilian counterparts and performed weight-bearing load carriage for nearly half of the day. Basic Combat Training-associated PA may increase injury risk among trainees unaccustomed to arduous PA and exercise. Implementing national PA policies to improve physical fitness and facilitate acclimatization to BCT's high physical demands could reduce public health burdens and military nonreadiness.

Sport Sciences↗
DOE OSTI2020

Development of a Conditioned System-Level Groundwater Model to Evaluate Long-Term Groundwater Impacts within a Performance Assessment - 20115

A preliminary performance assessment (PA) of single-shell tank Waste Management Area (WMA) A-AX located at the U.S. Department of Energy (DOE)'s Hanford Site in southeastern Washington is being conducted to satisfy the requirements of DOE Order 435.1 [1] as it relates to closure of the single-shell radioactive waste tanks in the WMA A-AX tank farms. A PA assesses the fate, transport, and impacts of radionuclides within a low-level radioactive waste disposal facility in its assumed closure configuration and the subsequent potential doses to humans over a 1,000-year compliance period and a 10,000-year performance evaluation period. The WMA A-AX preliminary PA evaluation is structured around the complementary use of process-level and system-level models to calculate the facility performance against established DOE Order 435.1 [1] performance objectives. Process-level models are those that represent a detailed phenomenological representation of processes of concern in the PA. Process models typically only represent one or a few of the components of the PA, such as groundwater flow and transport, and must be integrated with other modeling elements to perform PA calculations. System-level models are those that are abstracted from the process models, retaining the essential features of the process model, while allowing integration of all aspects of the PA in a single modeling framework. System-level models are often characterized by coarser numerical discretization, lower dimensionality, or other similar simplifications compared to the process-level model. Traditionally, a three-dimensional (3-D) process-level model is utilized primarily to evaluate the long-term impact on groundwater and the potential doses to individuals who consume contaminated groundwater. System-level models are also utilized to evaluate the groundwater pathway in PAs. These models typically have reduced dimensionality (1-D) and are conditioned utilizing flow fields (Darcy fluxes) and moisture content distributions that are abstracted from the process level models. The abstraction approach assures that the flow field in both models is consistent for a specific set of input parameters for flow, differing only in the discretization and dimensionality of the two models. The preliminary WMA A-AX PA incorporates a detailed representation of the geological system and hydraulic properties within the 3-D model STOMP{sup C} numerical code so that the effects of relevant features and processes on water flow and radionuclide transport in the subsurface can be evaluated. The complementary system-level model is developed utilizing the GoldSim{sup C} code to implement a simplified, 1-D equivalent model to represent the groundwater pathway. Contaminant transport through the vadose zone and unconfined aquifer for Tc-99 and I-129 were evaluated in each of the models. Adjustments to the saturated portion of the GoldSim{sup C} 1-D model were required to mimic the dispersion effect captured with the 3-D STOMP{sup C} model. Once this conditioning was conducted, highly similar results for the transport of Tc-99 and I-129 were achieved at the point of calculation, located 100 m downgradient from the WMA A-AX fenceline. These radionuclides represent elements that are regarded as primary dose drivers in the PA groundwater pathway analysis. The high degree of conformance between the two models suggests that the use of the equivalent 1-D system model is suitable for evaluating the full suite of radionuclides that will be released from the tank sources within WMA A-AX over the 1,000-year compliance period and over the 10,000-year evaluation period. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗