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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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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Distribution and migration mechanism of fluoride in groundwater in the Manas River Basin, Northwest China

Elevated fluoride (F) concentration in groundwater is posing a public health risk in the Manas River Basin (MRB), Northwest China. Based on the characterization of regional groundwater flow, 90 groundwater samples from aquifers were analyzed, along with top-soil leachate and pore-water samples from aquitards. Stable oxygen (δ{sup 18}O) and hydrogen isotopes, radiocarbon and hydrochemical analyses of the groundwater and pore-water samples were conducted to trace groundwater hydrological and hydrochemical processes and thereby understand the distribution and migration mechanism of F. The groundwater is recharged by meteoric precipitation through vapor condensation processes in the Tianshan Mountains. The F concentration in groundwater samples from this basin ranged from 0.11 to 48.15 mg/L (mean 2.56 mg/L). In 37 of the 90 groundwater samples, the F concentrations were above the safe level for drinking water. The F concentrations progressively increased with the residence time and well depths in the northwest of the alluvial-fluvial plain, where groundwater is overexploited for agricultural and domestic use. Positive correlations between F and sodium (Na)/calcium (Ca) indicate that the enrichment and migration of F are influenced by cation exchange processes under high-Na and alkaline pH conditions. The relationships between δ{sup 18}O and F and chloride (Cl) concentrations were nonlinear due to leaching and mixing processes. This shows that vertical leaching by irrigation return flow and mixing with pore water are the dominant processes driving the migration of F in the groundwater flow system of MRB, in addition to geochemical processes.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Non-radiative luminescence decay with self-trapped hole migration in strontium titanate: Interplay between optical and transport properties

A novel model for the non-radiative decay of self-trapped excitons (STEs) in the advanced functional oxide SrTiO3 is proposed and supported by experimental observations. The study is based on the initial ionoluminescence stage for STE emission at 2.5 eV, and its dependence on temperature and electronic excitation rate under energetic heavy-ion irradiation. For all temperatures, this initial stage reaches rapidly a quasi-steady level, and then decreases as induced-structural damage increases. The quasi-steady luminescence exhibits a linear dependence on the excitation rate, suggesting a constant efficiency for STEs formation. An activation energy of 55 meV, essentially independent of the incident ion mass and energy of projectile-ion, is deduced from an Arrhenius-type relationship with irradiation temperature. This energy is in good agreement with experimental values, measured for non-radiative STE decay under ns-laser pulse excitation, and reasonably consistent with density functional theory calculations for migration of self-trapped holes (STHs) described by a small-polaron adiabatic hopping model. A new mechanism dealing with a non-radiative contribution to the STE transition is discussed, consisting of STH migration through thermally-activated hopping and annihilation with the STE-electron. Luminescence kinetics from the chromium intrinsic impurity strongly supports this model, being consistent with the annihilation of Cr 3+ centers through recombination with migrating STHs.

luminescence↗
DOE OSTI2018

Loss of RapC causes defects in cytokinesis, cell migration, and multicellular development of Dictyostelium

Highlights: • We characterized the functions of RapC, an isoform of Rap1 small GTPase. • Loss of RapC causes defects in cytokinesis, cell migration, and development. • RapC plays a negative role in cell spreading and cell adhesion. • RapC is involved in tip formation from mounds during multicellular development. • This contributes to the understanding of Ras-mediated cellular processes. The small GTPase Ras proteins are involved in diverse cellular processes. We investigated the functions of RapC, one of 15 Ras subfamily GTPases in Dictyostelium. Loss of RapC resulted in a spread shape of cells; severe defects in cytokinesis leading to multinucleation; decrease of migration speed in chemoattractant-mediated cell migration, likely through increased cell adhesion; and aberrations in multicellular development producing abnormal multiple tips from one mound and multi-branched developmental structures. Defects in cells lacking RapC were rescued by expressing GFP-RapC in rapC null cells. Our results demonstrate that RapC, despite its high sequence homology with Rap1, plays a negative role in cell spreading and cell adhesion, in contrast to Rap1, which is a key regulator of cell adhesion and cytoskeleton rearrangement. In addition, RapC appears to have a unique function in multicellular development and is involved in tip formation from mounds. This study contributes to the understanding of Ras-mediated cellular processes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MiR-30a-5p inhibits osteosarcoma cell proliferation and migration by targeting FOXD1

Highlights: • FOXD1 is overexpressed in osteosarcoma while MiR-30a-5p is lowexpressed. • MiR-30a-5p directly regulates FOXD1 by binding its 3′-UTR. • Inhibition of FOXD1 suppresses osteosarcoma cell migration and invasion. • Inhibition of FOXD1 suppresses osteosarcoma cell proliferation in vitro and in vivo. Despite a number of studies have emphasized the extensive role of microRNA (miRNA) in the development of multiple cancers, the role of miR-30a-5p in the progression of osteosarcoma (OS) and the underlying mechanism are still limited. We detected the expression level of MiR-30a-5p and forkhead box D1 (FOXD1) in Clinical OS specimens and found that miR-30a-5p was significantly decreased while FOXD1 was markedly increased. Dual luciferase assay confirmed that FOXD1 was directly regulated by miR-30a-5p. In vitro assay showed that inhibitior of FOXD1 suppressed cell proliferation, migration and invasion in MG63 and U2OS cells, while overexpression of FOXD1 promoted OS cell proliferation and migration. In vivo assay further showed the inhibition of tumor growth after knockdown of FOXD1. These results suggested that FOXD1 might play key roles in OS development and progression, and was negatively regulated by miR-30a-5p in OS.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

CCN1 accelerates re-epithelialization by promoting keratinocyte migration and proliferation during cutaneous wound healing

Highlights: • Re-epithelialization is the restoration of skin integrity following injury. • CCN family member 1 (CCN1) is upregulated in the early stages following injury. • CCN1 promotes human primary keratinocyte migration and proliferation. • Topical CCN1 application stimulates re-epithelialization in mouse burn models. • CCN1 is more potent than bFGF in initiating re-epithelialization. Re-epithelialization is an essential part of wound healing and has a prominent influence on the prognosis. CCN family member 1 (CCN1 or Cysteine-rich 61, CYR61), a matricellular protein, has a potential role in the wound healing process. However, its role in re-epithelialization remains unclear. The aim of this study was to determine the expression of CCN1 in the epidermis and its effect on keratinocytes during re-epithelialization. CCN1 expression in the wounded skin was analyzed using microarray data from GEO database and detected by immunofluorescence. The results showed upregulated CCN1 during the early stages of wound healing. Human primary keratinocytes were treated with recombinant human CCN1. The results showed that CCN1 promoted keratinocyte migration and proliferation. Moreover, a full-thickness mouse skin wound model and a superficial second-degree burn mouse model treated intracutaneously with CCN1 were used for in vivo studies. Topical treatment with CCN1 protein accelerated wound closure and re-epithelialization. Additionally, longer newly-formed epithelium tongue and elevated expression of PCNA and Ki67 were detected in the CCN1-treated group 4 days post-burn. These results indicate that CCN1 accelerates re-epithelialization by promoting keratinocyte migration and proliferation, and may serve as a novel target to promote re-epithelialization.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MYPT1 is targeted by miR-145 inhibiting viability, migration and invasion in 2D and 3D HeLa cultures

Highlights: • miR-143/145 affect viability, migration and invasion on monolayer and spheroid cultures. • miR-145 produces a stronger inhibitory effect and increases pMLC levels through MYPT1 targeting. • MYPT1 silencing by siRNAs reproduces miR-145 effects. The miR-143/145 cluster is down-regulated in cervical tumor cells suggesting a role in tumorigenesis including cytoskeleton remodeling, a key event for tumor progression. The aim of the present work was to determine the role of miR-143/145 in the modulation of the myosin regulator phospho-myosin light chain (pMLC). HeLa monolayer and tridimensional cultures were transfected with miR-143 or miR-145 mimics inhibiting cell viability, proliferation, migration and invasion, mainly through miR-145. MiR-145 transfection increased pMLC levels by targeting the MYPT1 subunit of the regulatory myosin phosphatase. MYPT1 knockdown by siRNAs reproduced miR-145 effects suggesting miR-145 as a tumor suppressor through MYPT1 targeting, leading to a subsequent increase of pMLC levels with implications for cervical cell viability, migration and invasion.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

On the moisture migration of concrete subject to high temperature with different heating rates

A better understanding of moisture migration in concrete at high temperature can play an important role to improve the fire-resistance and radiation-shielding capability of concrete structures. In this regard, within the numerical framework of Multi-physics Lattice Discrete Particle Model, the moisture clog in concrete during heating is defined as the moisture-saturated region between the so-called “water front” and “water back” (isosurfaces of saturation = 1). The moisture migration in concrete subject to slow and fast heating has been investigated by simulating experimental tests in which moisture has been monitored via different techniques, namely 3D Neutron Tomography and Ground-Penetrating Radar. An overall consistency between experimental and numerical results has been observed, indirectly proving the effectiveness of numerical modelling and experimental monitoring of moisture migration.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Carboxyl-functionalized perovskite enables ALD growth of a compact and uniform ion migration barrier

Mixed-halide wide-band-gap perovskites are critical components of highly efficient tandem cells, but their operating stability is limited by halide migration. Metal oxides deposited via atomic layer deposition (ALD) have been shown to block halide migration; however, previously pursued methods result in inhomogeneous nucleation and growth. We hypothesized that functionalizing the perovskite surface with ALD-active carboxyl groups could promote nucleation and enable higher-temperature metal oxide growth. We find that 5-ammonium valeric acid iodide (5-AVAI) facilitates the formation of a compact and uniform aluminum oxide (Al 2 O 3 ) layer and allows growth at 100°C compared with the previous limit of 75°C. We demonstrate that halide migration into the C 60 electron transport layer is reduced by a factor of 10 compared with the reference case. Finally, Al 2 O 3 -capped perovskite solar cells with a band gap of 1.78 eV retain 90% of their initial power conversion efficiency after 1,000 h of continuous operation under 1-sun illumination at 55°C.

Al2O3↗
DOE OSTI2019

Approaches to multi-scale analyses of mechanically and thermally-driven migration of fluid inclusions in salt rocks

Fluid inclusions are found within mineral crystals or along grain boundaries in many sedimentary rocks, notably in evaporite formations, and can migrate along a thermal or hydro-mechanical gradient. Shale and salt rocks have been considered potential host rocks for radioactive waste disposal, due to their low permeability. Previously stagnant inclusions may become mobilised by a perturbation of the in situ state by a geotechnical installation or the emplacement of heat-generating waste. Here, the migration of fluid inclusions can thus have important impacts on the long-term performance of a geologic repository for high-level radioactive waste disposal. As a part of the international research project DECOVALEX-2019, two aspects of fluid inclusion migration in rock salt are currently investigated under different boundary conditions: a) altered hydro-mechanical conditions as a consequence of tunnel excavation or borehole drilling and b) coupled thermo-hydro-mechanical-chemical conditions during the heating period of the post-closure phase of a repository.

58 GEOSCIENCES↗
DOE OSTI2018

Heregulin-induced cell migration is promoted by aryl hydrocarbon receptor in HER2-overexpressing breast cancer cells

Highlights: • Heregulin signaling up-regulates AhR expression at the transcriptional level in HER2-overexpressing breast cancer cells. • Heregulin signaling induces nuclear translocation of AhR. • Knockout of the AhR decreases cell migration by heregulin signaling in HER2-overexpressing breast cancer cells. HER2 overexpression accounts for approximately 15–20% of all breast cancers. We have shown that HER2 overexpression leads to elevated expression of the aryl hydrocarbon receptor (AhR) in breast cancer cells. In this study, firstly, we showed that AhR expression was up-regulated by treatment with the HER3 ligand heregulin (HRG) in HER2-overexpressing breast cancer cell lines. Induction of AhR was mediated by transcriptional activation of the region of AhR promoter corresponding to − 190 to − 100 bp. In addition, HRG treatment elicited nuclear translocation of AhR. To investigate the role of AhR in HRG-HER2/HER3 signaling in HER2-overexpressing cells, we established AhR knockout (KO) HER2-overexpressing cells to perform wound-healing assays. HRG-induced cell migration was markedly attenuated by AhR KO. HRG-induced cell migration was associated with increased expression of the inflammatory cytokines interleukin (IL)-6 and IL-8 in wild type cells, but not in AhR KO cells. These results elucidate that AhR is an important factor for the malignancy in HER2 overexpressing breast cancers.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

ER-localized protein-Herpud1 is a new mediator of IL-4-induced macrophage polarization and migration

Highlights: • Herpud1 is induced by IL-4 in M2 macrophages. • Herpud1 is involved in IL-4 promoted polarization and migration of M2 macrophage. • Herpud1-associated ER stress play an important role in polarization and migration of M2 macrophage. ER-localized proteins have been reported function in endoplasmic reticulum, unfolded protein degradation and destruction of misfolded proteins by the ER-associated protein degradation (ERAD) system, but their function in the chemotaxis of macrophage cells remained un-addressed. Here, we showed that ER protein with ubiquitin like domain 1(Herpud1) was upregulated in IL-4-treated M2 macrophage cells and its expression pattern was similar with macrophage polarization markers, such as Arg1, Mrc1 and Fizz1. Inhibition of Herpud1 by using specific target shRNA decreased these marker's expression at mRNA and protein level in IL-4-treated or -untreated M2 macrophage cells. IL-4 treatment promoted M2 macrophage cell migration and polarization, but this promotion was weakened by Herpud1 depletion and we got similar results by inhibition of ER stress response with chemical molecule 4-phenylbutyric acid (4-PBA) in IL-4-treated or untreated-M2 macrophage cells with Herpud1 overexpression. These results indicated that depending on ER-associated protein degradation (ERAD) to help unfolded protein degradation or destruction is not the only function of Herpud1 and acting as a mediator of IL-4 induced macrophage activation and polarization maybe another unrevealed function, elucidating the role of Herpud1-associated M2 macrophage cell polarization and activation are helpful for exploration the function of macrophage cells in immune response.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Long non-coding RNA UCA1 upregulation promotes the migration of hypoxia-resistant gastric cancer cells through the miR-7-5p/EGFR axis

Highlights: • Two novel hypoxia-resistant gastric cancer (HRGC) cell lines were established. • UCA1 was upregulated in HRGC cells, which promoted their migration. • UCA1 directly interacted with miR-7-5p. • UCA1 suppressed the degradation of EGFR mRNA by sponging miR-7-5p. A variety of solid tumors are surrounded by a hypoxic microenvironment, which is known to be associated with high metastatic capability and resistance to various clinical therapies, contributing to a poor survival rate for cancer patients. Although the majority of previous studies on tumor-associated hypoxia have focused on acute hypoxia, chronic hypoxia more closely mimics the actual hypoxic microenvironment of a tumor. In this study, two novel hypoxia-resistant gastric cancer (HRGC) cell lines which could grow normally in 2% oxygen were established. The long non-coding RNA UCA1 was upregulated in HRGC cells, which promoted their migration. Bioinformatics analysis and a luciferase reporter assay showed that miR-7-5p could bind to specific sites of UCA1 to regulate the target EGFR through competitive endogenous RNA function. UCA1 directly interacted with miR-7-5p and decreased the binding of miR-7-5p to the EGFR 3′-untranslated region, which suppressed the degradation of EGFR mRNA by miR-7-5p. Therefore, long-term hypoxia induced UCA1 to promote cell migration by enhancing the expression of EGFR. This study thus reveals a new mechanism by which a hypoxic microenvironment promotes tumor metastasis, and highlights UCA1 as a potential biomarker for predicting the metastasis of gastric cancer to guide clinical treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Fibronectin amyloid-like aggregation alters its extracellular matrix incorporation and promotes a single and sparsed cell migration

Highlights: • Fibronectin can polymerize into amyloid-like aggregates. • Fibronectin amyloid-like aggregates promote a sparsed cell migration. • The supramolecular state of fibronectin could fine-tune cell phenotype. Fibronectin (Fn) is an extracellular matrix (ECM) multifunctional glycoprotein essential for regulating cells behaviors. Within ECM, Fn is found as polymerized fibrils. Apart from fibrils, Fn could also form other kind of supramolecular assemblies such as aggregates. To gain insight into the impact of Fn aggregates on cell behavior, we generated several Fn oligomeric assemblies. These assemblies displayed various amyloid-like properties but were not cytotoxic. In presence of the more amyloid-like structured assemblies of Fn, the cell-ECM networks were altered and the cell shapes shifted toward extended mesenchymal morphologies. Additionnaly, the Fn amyloid-like aggregates promoted a single-cell and sparsed migration of SKOV3 cancer cells, which was associated with a relocalization of αv integrins from plasma membrane to perinuclear vesicles. These data pointed out that the features of supramolecular Fn assemblies could represent a higher level of fine-tuning cell phenotype, and especially migration of cancer cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MiR-940 promotes the proliferation and migration of gastric cancer cells through up-regulation of programmed death ligand-1 expression

Although anti-programmed death ligand-1 (PD-L1) therapy has shown light in treatment of gastric cancer, only a limited number of patients respond to the treatment. In addition to its immunosuppressive effect, PD-L1 is involved in other functions of tumor cells. Previously study showed that PD-L1 promoted EMT in lung cancer cells. However, the other effect and role of PD-L1 in gastric cancer remains unclear. In the present study, we first demonstrated that PD-L1 promoted the proliferation and migration in gastric cancer cell lines. We found that another STAT family member, STAT5a, is involved in regulating the expression of PD-L1 in gastric cancer. Additionally, Cbl-b interacted and ubiquitated STAT5a, down-regulated the expression of STAT5a and PD-L1. Moreover, bioinformatics predictions and experimental data showed that Cbl-b is a target gene of the microRNA miR-940. We further found that miR-940 promoted the proliferation and migration of gastric cancer in vivo and in vitro. Taken together, our findings suggest that miR-940/Cbl-b/STAT5a axis regulated the expression of PD-L1, which promotes the proliferation and migration of gastric cancer cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

PCGF3 promotes the proliferation and migration of non-small cell lung cancer cells via the PI3K/AKT signaling pathway

Highlights: • PCGF3 is highly expressed in non-small cell lung cancer (NSCLC) tissues. • PCGF3 overexpression positively correlates with lymph node metastasis and p-TNM staging. • PCGF3 promotes NSCLC cells proliferation by regulating CyclinB1, CyclinD1, and CDK4. • PCGF3 promotes NSCLC cells migration by regulating RhoA, RhoC, and CDC42. • PCGF3 promotes malignant behavior in NSCLC by positively regulating the PI3K/AKT signaling pathway. The Polycomb Group Ring Finger 3 (PCGF3) protein has been reported to be significantly upregulated in pancreatic islet tumors and related to signal transduction; however, its detailed mechanisms and biological roles in other tumors, including non-small cell lung cancer (NSCLC), remain unclear. This study investigated the function of PCGF3 in NSCLC and further elucidated its mechanism of action. The immunohistochemical analysis of 86 selected lung cancer tissues revealed that PCGF3 was highly expressed in NSCLC tissues and positively correlated with lymph node metastasis and p-TNM staging. Additionally, PCGF3 promoted cell proliferation in lung cancer by regulating CyclinB1, CyclinD1, and CDK4 expression, and also promoting their migration by regulating RhoA, RhoC, and CDC42. Furthermore, PCGF3 affected both the proliferation and migration of lung cancer cells by regulating the PI3K/AKT pathway, as verified by inhibiting this pathway using LY294002. The findings of this study suggested that PCGF3 is associated with poor prognosis in patients with NSCLC and could therefore be an important biomarker for treating and preventing NSCLC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Injectable platelet rich fibrin facilitates hair follicle regeneration by promoting human dermal papilla cell proliferation, migration, and trichogenic inductivity

Hair follicle regeneration has been successful in mice but failed in human being for years. Dermal papilla cells, a specialized mesenchymal stem cell derived from dermal papilla within hair follicles, is considered the key cells for hair follicle regeneration function as both regeneration initiator and regulator. Injectable platelet rich fibrin (i-PRF), a novel biomaterial rich in a variety of growth factors and three-dimensional scaffolds, has shown promising effects on tissue regeneration. In this study, we aimed to evaluate the application of i-PRF in human hair follicle regeneration by examining the biological effects of i-PRF on human dermal papilla cells (hDPCs). Biomaterial compatibility, cell viability, proliferation, migration, alkaline phosphatase activity and trichogenic inductivity were assessed after exposing hDPCs to different concentrations of i-PRF extracts. In addition, we investigated the ultrastructure of i-PRF with all cell components filtered. The results revealed that i-PRF possessing excellent biocompatibility and could significantly promote hDPCs proliferation, migration, and trichogenic inductivity. Furthermore, the concentration of i-PRF is able to remarkably influence hDPCs behavior in a dose-dependent pattern. Different concentrations exhibited differential effects on hDPCs behavior. In general, lower concentration promotes cell proliferation better than higher concentration, while higher concentration promotes cell function better reversely. Best concentration for hDPCs in vitro expending is 1% concentration. 20% concentration is optimal for hair follicle regeneration. In summary, our findings concluded that i-PRF facilitates hair follicle regeneration by promoting human dermal papilla cell proliferation, migration, and trichogenic inductivity.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Strain Relaxation-Induced Twin Interface Migration and Morphology Evolution of Silver Nanoparticles

The twinned structure of nanoscale metal particles is considered to be an important factor in the formation of novel morphologies. Nevertheless, most studies are focused on the growth of nanoparticles with stable twinned structures, and little is known about the intrinsic relationship between the morphological evolution and the strain relaxation induced by twin boundary migration. In this study, we elucidated the mechanisms of symmetry breaking induced by strain relaxation in Ag nanoparticles by employing transmission electron microscopy, electron tomography, and strain analysis. The experimental results reveal that decahedral nanoparticles larger than ~ 50 nm evolve into asym-metrical rhomboid pyramids to relax the lattice strain energy in the fivefold twin through twin pole migration. This migration is achieved by coordinating slipping and dissociating of partial and perfect dislocations. In addition, we found that the rhomboid pyramid further evolves into a rhomboid bar during growth in a specific way to avoid in-creasing the strain energy in the crystal.

Song, Miao↗
DOE OSTI2019

Probing Mg Migration in Spinel Oxides

Mg batteries utilizing oxide cathodes can theoretically surpass the energy density of current Li-ion technologies. The absence of functional devices so far has been ascribed to impeded Mg 2+ migration within oxides, which severely handicaps intercalation reactions at the cathode. Broadly, knowledge of divalent cation migration in solid frameworks is surprisingly deficient. In this paper, we present a combined experimental and theoretical study of Mg migration within three spinel oxides, which reveal critical features that influence it. Experimental activation energies for a Mg 2+ hop to an adjacent vacancy, as low as ~0.6 eV, are reported. These barriers are low enough to support functional electrodes based on the intercalation of M g2+ . Subsequent electrochemical experiments demonstrate that significant demagnesiation is indeed possible, but the challenges instead lie with the chemical stability of the oxidized states. Our findings enhance the understanding of cation transport in solid structures and renew the prospects of finding materials capable of high density of energy storage.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗