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Results for “cell analysis”

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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Red cell metabolism studies on Skylab

Blood samples from Spacelab crewmembers were studied for possible environment effects on red cell components. Analysis involved peroxidation of red cell lipids, enzymes of red cell metabolism, and levels of 2,3-diphosphoglyceric acid and adenosine triphosphate. Results show that there is no evidence of lipid peroxidation, that biochemical effect known to be associated with irreversible red cell damage. Changes observed in glycolytic intermediates and enzymes cannot be directly implicated as indicating evidence of red cell damage.

Mengel, C. E.↗
DOE OSTI2019

Texture analysis of small renal cell carcinomas at MDCT for predicting relevant histologic and protein biomarkers

Purpose: To assess CT texture features of small renal cell carcinomas (≤ 4cm) for association with key pathologic features including protein biomarkers. Methods: Quantitative CT texture analysis (CTTA) of small renal cancers (≤ 4cm) was performed on non-contrast and portal venous phase abdominal MDCT scans with an ROI drawn at the largest cross-sectional diameter of the tumor using commercially available software. Texture parameters including mean pixel attenuation, the standard deviation (SD) of the pixel distribution histogram, entropy, the mean of positive pixels, the skewness (i.e., asymmetry) of the pixel histogram, kurtosis (i.e., peakness) of the pixel histogram, and the percentage of positive pixels were correlated with pathologic data from surgical resection, including histology and nuclear grade, as well as microarray analysis in a subset (n = 40) including Ki67 index, CRP, and neovascularization (CD105/CD31). Results: Portal venous phase images were available in 249 patients (105 women, 144 men; mean age, 56.7 years) with tumors ≤ 4cm (mean, median, range, ± SD; 2.66, 2.60, 0.3–4.0 ± 0.85 cm). CT texture features of standard deviation, mean of the positive pixels, and entropy of the pixel histogram were significantly associated with histologic cell type (clear vs. non-clear; p < 0.001). Entropy and mean of the positive pixels also showed an association with nuclear grade, although not statistically significant. In the microarray analysis subset, kurtosis of the pixel histogram was associated with CD105/CD31 (p = 0.05). SD also showed some association with CD 105 positivity (p = 0.02) and CAIX expression (p = 0.01). Non-contrast CT images were available in 174 patients (72 women, 102 men; mean age, 57.5 years). Although the association with histology was not as strong as on the portal venous phase, in the subset of patients with microarray data, SD was found to correlate with CRP (p = 0.08), kurtosis with CRP (p = 0.004), CD105/CD31 (p = 0.002), and with Ki 67 index (p < 0.001). Conclusion: CT texture features were significantly associated with important histopathologic features in small renal cancers. These non-invasive measures can be performed retrospectively and may provide useful information when determining follow-up and treatment of small renal cancers.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
NASA NTRS1981

Transport velocity transformation - A convenient method for performance analysis of multilayer solar cell structure

It is noted that in the case of low-level injection, space-charge quasi-neutrality, and spatially constant material parameters (including an electrostatic field), the individual layer can be treated analytically and the basic solar cell performance parameters can be evaluated from three equations. The first equation represents the transformation of the transport velocity across the layer from the other layer boundary. The second establishes the light-generated current output from the layer interface, under the influence of the transport velocities and minority-carrier density at both layer boundaries and of bulk recombination. The third equation describes the flow of these carriers across other layers. The power of the approach is considered to lie in its facility for analysis of the solar cell's performance layer by layer, giving a clear picture of the individual layer's influence on cell efficiency.

Wolf, M.↗
DOE OSTI2014

Inhibition of influenza virus infection and hemagglutinin cleavage by the protease inhibitor HAI-2

Highlights: • Biochemical and cell biological analysis of HAI-2 as an inhibitor of influenza HA cleavage activation. • Biochemical and cell biological analysis of HAI-2 as an inhibitor of influenza virus infection. • Comparative analysis of HAI-2 for vesicular stomatitis virus and human parainfluenza virus type-1. • Analysis of the activity of HAI-2 in a mouse model of influenza. - Abstract: Influenza virus remains a significant concern to public health, with the continued potential for a high fatality pandemic. Vaccination and antiviral therapeutics are effective measures to circumvent influenza virus infection, however, multiple strains have emerged that are resistant to the antiviral therapeutics currently on the market. With this considered, investigation of alternative antiviral therapeutics is being conducted. One such approach is to inhibit cleavage activation of the influenza virus hemagglutinin (HA), which is an essential step in the viral replication cycle that permits viral-endosome fusion. Therefore, targeting trypsin-like, host proteases responsible for HA cleavage in vivo may prove to be an effective therapeutic. Hepatocyte growth factor activator inhibitor 2 (HAI-2) is naturally expressed in the respiratory tract and is a potent inhibitor of trypsin-like serine proteases, some of which have been determined to cleave HA. In this study, we demonstrate that HAI-2 is an effective inhibitor of cleavage of HA from the human-adapted H1 and H3 subtypes. HAI-2 inhibited influenza virus H1N1 infection in cell culture, and HAI-2 administration showed protection in a mouse model of influenza. HAI-2 has the potential to be an effective, alternative antiviral therapeutic for influenza.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Learning perturbation-inducible cell states from observability analysis of transcriptome dynamics

Abstract A major challenge in biotechnology and biomanufacturing is the identification of a set of biomarkers for perturbations and metabolites of interest. Here, we develop a data-driven, transcriptome-wide approach to rank perturbation-inducible genes from time-series RNA sequencing data for the discovery of analyte-responsive promoters. This provides a set of biomarkers that act as a proxy for the transcriptional state referred to as cell state. We construct low-dimensional models of gene expression dynamics and rank genes by their ability to capture the perturbation-specific cell state using a novel observability analysis. Using this ranking, we extract 15 analyte-responsive promoters for the organophosphate malathion in the underutilized host organism Pseudomonas fluorescens SBW25. We develop synthetic genetic reporters from each analyte-responsive promoter and characterize their response to malathion. Furthermore, we enhance malathion reporting through the aggregation of the response of individual reporters with a synthetic consortium approach, and we exemplify the library’s ability to be useful outside the lab by detecting malathion in the environment. The engineered host cell, a living malathion sensor, can be optimized for use in environmental diagnostics while the developed machine learning tool can be applied to discover perturbation-inducible gene expression systems in the compendium of host organisms.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS2003

Probabilistic Analysis of Solid Oxide Fuel Cell Based Hybrid Gas Turbine System

The emergence of fuel cell systems and hybrid fuel cell systems requires the evolution of analysis strategies for evaluating thermodynamic performance. A gas turbine thermodynamic cycle integrated with a fuel cell was computationally simulated and probabilistically evaluated in view of the several uncertainties in the thermodynamic performance parameters. Cumulative distribution functions and sensitivity factors were computed for the overall thermal efficiency and net specific power output due to the uncertainties in the thermodynamic random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design and make it cost effective. The analysis leads to the selection of criteria for gas turbine performance.

Gorla, Rama S. R.↗
NASA NTRS1976

Theoretical analysis of Al/x/Ga/1-x/As-GaAs graded band-gap solar cell

A practical theoretical analysis of an n/p graded band-gap Al(x)Ga(1-x)As-GaAs solar cell indicates that the presence of a built-in electric field acting on holes in the surface layer increases the hole collection efficiency of a nearly optimum cell to a maximum of 97.8%. The electric field is created by the band-gap gradient and serves to reduce the surface hole recombination by 97% and reduce the bulk hole recombination by 80%, compared to a similar GaAs cell. These reduced losses increase cell response substantially for wavelengths less than 0.59 micron and yield a maximum air-mass-zero efficiency of 17.7% (not corrected for a 13% front-surface contact). The model includes an optimized antireflection coating, series resistance, and junction-recombination current.

Hutchby, J. A.↗
NASA NTRS1981

Silicon solar cell process development, fabrication, and analysis

Two large cast ingots were evaluated. Solar cell performance versus substrate position within the ingots was obtained and the results are presented. Dendritic web samples were analyzed in terms of structural defects, and efforts were made to correlate the data with the performance of solar cells made from the webs.

Yoo, H. I.↗
NASA NTRS1984

Failure analysis of thin-film amorphous-silicon solar-cell modules

A failure analysis of thin film amorphous silicon solar cell modules was conducted. The purpose of this analysis is to provide information and data for appropriate corrective action that could result in improvements in product quality and reliability. Existing techniques were expanded in order to evaluate and characterize degradational performance of a-Si solar cells. Microscopic and macroscopic defects and flaws that significantly contribute to performance degradation were investigated.

Kim, Q.↗
DOE OSTI2018

Phosphoproteomic analysis reveals PAK2 as a therapeutic target for lapatinib resistance in HER2-positive breast cancer cells

Highlights: • Phosphoproteomic analysis identified PAK2 as a drug target for lapatinib resistance. • PAK2 knockdown restores lapatinib sensitivity of lapatinib-resistant SKBR-LR cells. • Cotreatment of lapatinib with PAK inhibitor restores the sensitivity to lapatinib. The human epidermal growth factor receptor 2 (HER2)-positive breast cancer with overexpression of HER2 accounts for approximately 25% of breast cancers and is more aggressive than other types of breast cancer. Lapatinib has been widely used as a HER2-targeted therapy, however, a number of patients develop lapatinib resistance and still suffer from poor prognosis. Therefore, it is essential to identify novel therapeutic targets that could overcome lapatinib resistance. In this study, we carried out phosphoproteomic analysis of lapatinib sensitive and resistant cell lines (SKBR3 and SKBR3-LR) using stable isotope labeling with amino acids in cell culture (SILAC). We identified 3808 phosphopeptides from 1807 proteins and then analyzed signaling pathways, Gene Ontology, and protein-protein interaction networks. Finally, we identified PAK2 as a therapeutic target from the network analysis and validated that PAK2 knockdown and PAK inhibitor treatment resensitize the lapatinib resistant cells to lapatinib. This results suggest that PAK2 is a potent therapeutic target to overcome acquired lapatinib resistance in HER2-positive breast cancer cells.

60 APPLIED LIFE SCIENCES↗
NASA NTRS2004

Displacement Damage Effects in Solar Cells: Mining Damage From the Microelectronics and Photonics Test Bed Space Experiment

The objective is to develop an improved space solar cell radiation response analysis capability and to produce a computer modeling tool which implements the analysis. This was accomplished through analysis of solar cell flight data taken on the Microelectronics and Photonics Test Bed experiment. This effort specifically addresses issues related to rapid technological change in the area of solar cells for space applications in order to enhance system performance, decrease risk, and reduce cost for future missions.

Hardage, Donna↗
DOE OSTI2021

Exploring Transport Behavior in Hybrid Perovskites Solar Cells via Machine Learning Analysis of Environmental-Dependent Impedance Spectroscopy

Hybrid organic–inorganic perovskites are one of the promising candidates for the next-generation semiconductors due to their superlative optoelectronic properties. However, one of the limiting factors for potential applications is their chemical and structural instability in different environments. Herein, the stability of (FAPbI3)0.85(MAPbBr3)0.15 perovskite solar cell is explored in different atmospheres using impedance spectroscopy. An equivalent circuit model and distribution of relaxation times (DRTs) are used to effectively analyze impedance spectra. DRT is further analyzed via machine learning workflow based on the non-negative matrix factorization of reconstructed relaxation time spectra. This exploration provides the interplay of charge transport dynamics and recombination processes under environment stimuli and illumination. The results reveal that in the dark, oxygen atmosphere induces an increased hole concentration with less ionic character while ionic motion is dominant under ambient air. Under 1 Sun illumination, the environment-dependent impedance responses show a more striking effect compared with dark conditions. In this case, the increased transport resistance observed under oxygen atmosphere in equivalent circuit analysis arises due to interruption of photogenerated hole carriers. The results not only shed light on elucidating transport mechanisms of perovskite solar cells in different environments but also offer an effective interpretation of impedance responses.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Scale-up and techno-economic analysis of microbial electrolysis cells for hydrogen production from wastewater

Microbial electrolysis cells (MECs) have demonstrated high-rate H 2 production while concurrently treating wastewater, but the transition in scale from laboratory research to systems that can be practically applied has encountered challenges. It has been more than a decade since the first pilot-scale MEC was reported, and in recent years, many attempts have been made to overcome the barriers and move the technology to the market. This study provided a detailed analysis of MEC scale-up efforts and summarized the key factors that should be considered to further develop the technology. We compared the major scale-up configurations and systematically evaluated their performance from both technical and economic perspectives. We characterized how system scale-up impacts the key performance metrics such as volumetric current density and H 2 production rate, and we proposed methods to evaluate and optimize system design and fabrication. In addition, preliminary techno-economic analysis indicates that MECs can be profitable in many different market scenarios with or without subsidies. Here, we also provide perspectives on future development needed to transition MEC technology to the marketplace.

42 ENGINEERING↗
DOE OSTI2014

No Clinically Significant Changes in Pulmonary Function Following Stereotactic Body Radiation Therapy for Early- Stage Peripheral Non-Small Cell Lung Cancer: An Analysis of RTOG 0236

Purpose: To investigate pulmonary function test (PFT) results and arterial blood gas changes (complete PFT) following stereotactic body radiation therapy (SBRT) and to see whether baseline PFT correlates with lung toxicity and overall survival in medically inoperable patients receiving SBRT for early stage, peripheral, non-small cell lung cancer (NSCLC). Methods and Materials: During the 2-year follow-up, PFT data were collected for patients with T1-T2N0M0 peripheral NSCLC who received effectively 18 Gy × 3 in a phase 2 North American multicenter study (Radiation Therapy Oncology Group [RTOG] protocol 0236). Pulmonary toxicity was graded by using the RTOG SBRT pulmonary toxicity scale. Paired Wilcoxon signed rank test, logistic regression model, and Kaplan-Meier method were used for statistical analysis. Results: At 2 years, mean percentage predicted forced expiratory volume in the first second and diffusing capacity for carbon monoxide declines were 5.8% and 6.3%, respectively, with minimal changes in arterial blood gases and no significant decline in oxygen saturation. Baseline PFT was not predictive of any pulmonary toxicity following SBRT. Whole-lung V5 (the percentage of normal lung tissue receiving 5 Gy), V10, V20, and mean dose to the whole lung were almost identical between patients who developed pneumonitis and patients who were pneumonitis-free. Poor baseline PFT did not predict decreased overall survival. Patients with poor baseline PFT as the reason for medical inoperability had higher median and overall survival rates than patients with normal baseline PFT values but with cardiac morbidity. Conclusions: Poor baseline PFT did not appear to predict pulmonary toxicity or decreased overall survival after SBRT in this medically inoperable population. Poor baseline PFT alone should not be used to exclude patients with early stage lung cancer from treatment with SBRT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2024

Open aperture flow cells for on-line optical analysis of process fluids

A flow cell system includes a vessel and a fluid located in the vessel. A fluid surface of the fluid can be vented to a first gas pressure. The fluid surface can have a first cross-sectional area. The flow cell system includes a conduit in fluid communication with the vessel and positioned downstream of the vessel. The conduit can have a region that includes one or more orifices and has a second cross-sectional area. The second cross-sectional area can be less than the first cross-sectional area. The one or more orifices can be vented to a second gas pressure. The second gas pressure can be equal to or greater than the first gas pressure. Methods for analyzing a process fluid can include characterizing the fluid in the conduit.

Launiere, Cari A.↗
DOE OSTI2017

Curcumin inhibits bladder cancer stem cells by suppressing Sonic Hedgehog pathway

Cancer stem cells (CSCs) is responsible for the recurrence of human cancers. Thus, targeting CSCs is considered to be a valid way for human cancer treatment. Curcumin is a major component of phytochemicals that exerts potent anticancer activities. However, the effect of curcumin on bladder cancer stem cells (BCSCs) remains to be elucidated. In this study, we investigated the mechanism of curcumin suppressing bladder cancer stem cells. In this study, UM-UC-3 and EJ cells were cultured in serum-free medium (SFM) to form cell spheres that was characterized as BCSCs. Then cell spheres were separately treated with different concentrations of curcumin and purmorphamine. Cell cycle analysis were used to determine the percentage of cells in different phases. Western blot and quantitative real-time PCR analysis were used to detect the expression of relative molecules. Immunofluorescence staining analysis were also utilized to measure the protein level of CD44. We found that CSC markers, including CD44, CD133, ALDH1-A1, OCT-4 and Nanog, were obviously highly expressed in cell spheres. Moreover, we observed that curcumin reduced the cell spheres formation, decreased the expression of CSC markers, suppressed cell proliferation and induced cell apoptosis. We also found that curcumin inhibited the activation of Shh pathway, while the inhibitory effects of curcumin on BCSCs could be weakened by upregulation of Sonic Hedgehog (Shh) pathway. Altogether, these data suggested that curcumin inhibited the activities of BCSCs through suppressing Shh pathway, which might be an effective chemopreventive agent for bladder cancer intervention.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1977

SMS/GOES cell and battery data analysis report

The nickel-cadmium battery design developed for the Synchronous Meteorological Satellite (SMS) and Geostationary Operational Environmental Satellite (GOES) provided background and guidelines for future development, manufacture, and application of spacecraft batteries. SMS/GOES battery design, development, qualification testing, acceptance testing, and life testing/mission performance characteristics were evaluated for correlation with battery cell manufacturing process variables.

Armantrout, J. D.↗