Performance and life evaluation of advanced battery technologies for electric vehicle applications

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

Advanced battery technology evaluations are performed under simulated electric vehicle (EV) operating conditions at the Argonne Analysis and Diagnostic Laboratory (ADL). The ADL provides a common basis for both performance characterization and life evaluation with unbiased application of tests and analyses. This paper summarizes the performance characterizations and life evaluations conducted in 1990 on nine single cells and fifteen 3- to 360-cell modules that encompass six technologies: (Na/S, Zn/Br, Ni/Fe, Ni/Cd, Ni-metal hydride, and lead-acid). These evaluations were performed for the Department of Energy and Electric Power Research Institute. The results provide battery users, developers, and program managers an interim measure of the progress being made in battery R and D programs, a comparison of battery technologies, and a source of basic data for modelling and continuing R and D.

Performance Demonstration of Mcmb-LiNiCoO2 Cells Containing Electrolytes Designed for Wide Operating Temperature Range

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Whicanack, L. D.; Smith, K. A.; Santee, S.; Puglia, F. J.; Gitzendanner, R.

2009-01-01

With the intent of improving the performance of Li-ion cells over a wide operating temperature range, we have investigated the use of co-solvents to improve the properties of electrolyte formulations. In the current study, we have focused upon evaluating promising electrolytes which have been incorporated into large capacity (7 Ah) prototype Li-ion cells, fabricated by Yardney Technical Products, Inc. The electrolytes selected for performance evaluation include the use of a number of esters as co-solvents, including methyl propionate (MP), ethyl propionate (EP), ethyl butyrate (EB), propyl butyrate (PB), and 2,2,2-trifluoroethyl butyrate (TFEB). The performance of the prototype cells containing the ester-based electrolytes was compared with an extensive data base generated on cells containing previously developed all carbonate-based electrolytes. A number of performance tests were performed, including determining (i) the discharge rate capacity over a wide range of temperatures, (ii) the charge characteristics, (iii) the cycle life characteristics under various conditions, and (iv) the impedance characteristics.

Analysis and evaluation in the production process and equipment area of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Wolf, M.

1981-01-01

The effect of solar cell metallization pattern design on solar cell performance and the costs and performance effects of different metallization processes are discussed. Definitive design rules for the front metallization pattern for large area solar cells are presented. Chemical and physical deposition processes for metallization are described and compared. An economic evaluation of the 6 principal metallization options is presented. Instructions for preparing Format A cost data for solar cell manufacturing processes from UPPC forms for input into the SAMIC computer program are presented.

Calorimetric evaluation of commercial Ni-MH cells and charges

NASA Technical Reports Server (NTRS)

Darcy, Eric C.; Hughes, Brent M.

1995-01-01

The test objectives are to evaluate the electrical and thermal performance of commercial Ni-MH cells and to evaluate the effectiveness of commercial charge control circuits. The ultimate design objectives are to determine which cell designs are most suitable for scale-up and to guide the design of future Shuttle and Station based battery chargers.

Key results of battery performance and life tests at Argonne National Laboratory

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

1991-12-01

Advanced battery technology evaluations are performed under simulated electric vehicle operating conditions at Argonne National Laboratory's & Diagnostic Laboratory (ADL). The ADL provide a common basis for both performance characterization and life evaluation with unbiased application of tests and analyses. This paper summarizes the performance characterizations and life evaluations conducted in 1991 on twelve single cells and eight 3- to 360-cell modules that encompass six battery technologies (Na/S, Li/MS, Ni/MH, Zn/Br, Ni/Fe, and Pb-Acid). These evaluations were performed for the Department of Energy, Office of Transportation Technologies, Electric and Hybrid Propulsion Division. The results measure progress in battery R & D programs, compare battery technologies, and provide basic data for modeling and continuing R & D to battery users, developers, and program managers.

Evaluation program for secondary spacecraft cells

NASA Technical Reports Server (NTRS)

Christy, D. E.

1972-01-01

The life cycle test of secondary spacecraft electric cells is discussed. The purpose of the tests is to insure that all cells put into the life cycle test meet the required specifications. The evaluation program gathers statistical information concerning cell performance characteristics and limitations. Weaknesses in cell design which are discovered during the tests are reported to research facilities in order to increase the service life of the cells.

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

NASA Technical Reports Server (NTRS)

Gorla, Rama S. R.; Pai, Shantaram S.; Rusick, Jeffrey J.

2003-01-01

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.

Durability evaluation of reversible solid oxide cells

NASA Astrophysics Data System (ADS)

Zhang, Xiaoyu; O'Brien, James E.; O'Brien, Robert C.; Housley, Gregory K.

2013-11-01

An experimental investigation on the performance and durability of single solid oxide cells (SOCs) is under way at the Idaho National Laboratory. Reversible operation of SOCs includes electricity generation in the fuel cell mode and hydrogen generation in the electrolysis mode. Degradation is a more significant issue when operating SOCs in the electrolysis mode. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOCs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. Cells were obtained from four industrial partners. Cells from Ceramatec Inc. and Materials and Systems Research Inc. (MSRI) showed improved durability in electrolysis mode compared to previous stack tests. Cells from Saint Gobain Advanced Materials Inc. (St. Gobain) and SOFCPower Inc. demonstrated stable performance in the fuel cell mode, but rapid degradation in the electrolysis mode, especially at high current density. Electrolyte-electrode delamination was found to have a significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the electrode microstructure helped to mitigate degradation. Polarization scans and AC impedance measurements were performed during the tests to characterize cell performance and degradation.

Gas-cell measurements for evaluating longwave-infrared passive-sensor performance

NASA Astrophysics Data System (ADS)

Cummings, Alan S.; Combs, Roger J.; Thomas, Mark J.; Curry, Timothy; Kroutil, Robert T.

2006-10-01

A longwave-infrared (LWIR) passive-spectrometer performance was evaluated with a short-pathlength gas cell. This cell was accurately positioned between the sensor and a NIST-traceable blackbody radiance source. Cell contents were varied over the Beer's Law absorbance range from the limit of detection to saturation for the gas analytes of sulfur hexafluoride and hexafluoroethane. The spectral impact of saturation on infrared absorbance was demonstrated for the passive sensor configuration. The gas-cell contents for all concentration-pathlength products was monitored with an active traditional-laboratory Fourier Transform Infrared (FTIR) spectrometer and was verified by comparison with the established PNNL/DOE vapor-phase infrared (IR) spectral database. For the passive FTIR measurements, the blackbody source employed a range of background temperatures from 5 °C to 50 °C. The passive measurements without the presence of a gas cell permitted a determination of the noise equivalent spectral noise (NESR) for each set of passive gas-cell measurements. In addition, the no-cell condition allowed the evaluation of the effect of gas cell window materials of low density poly(ethylene), potassium chloride, potassium bromide, and zinc selenide. The components of gas cell, different window materials, temperature differentials, and absorbances of target-analyte gases supplied the means of evaluating the LWIR performance of a passive FTIR spectrometer. The various LWIR-passive measurements were found to simulate those often encountered in open-air scenarios important to both industrial and environmental monitoring applications.

Cycle analysis of MCFC/gas turbine system

NASA Astrophysics Data System (ADS)

Musa, Abdullatif; Alaktiwi, Abdulsalam; Talbi, Mosbah

2017-11-01

High temperature fuel cells such as the solid oxide fuel cell (SOFC) and the molten carbonate fuel cell (MCFC) are considered extremely suitable for electrical power plant application. The molten carbonate fuel cell (MCFC) performances is evaluated using validated model for the internally reformed (IR) fuel cell. This model is integrated in Aspen Plus™. Therefore, several MCFC/Gas Turbine systems are introduced and investigated. One of this a new cycle is called a heat recovery (HR) cycle. In the HR cycle, a regenerator is used to preheat water by outlet air compressor. So the waste heat of the outlet air compressor and the exhaust gases of turbine are recovered and used to produce steam. This steam is injected in the gas turbine, resulting in a high specific power and a high thermal efficiency. The cycles are simulated in order to evaluate and compare their performances. Moreover, the effects of an important parameters such as the ambient air temperature on the cycle performance are evaluated. The simulation results show that the HR cycle has high efficiency.

Evaluation and verification of epitaxial process sequence for silicon solar-cell production

NASA Technical Reports Server (NTRS)

Redfield, D.

1981-01-01

To achieve the program goals, 28 minimodules were fabricated and tested, using 600 cells made from three-inch-diameter wafers processed by the sequence chosen for this purpose. Of these 600 cells, half were made from epitaxially grown layers on potentially low-cost substrates. The other half were made from commercial semiconductor-grade (SG), single-crystal silicon wafers that served as controls. Cell processing was normally performed on mixed lots containing significant numbers of each of these two types of wafers. After evaluation of the performance of all cells, they were separated by types for incorporation into modules that were to be tested for electrical performance and response to environmental stress. A simplified flow chart displaying this scheme, for quantities representing half of the planned total to be processed, is presented.

Primary lithium-thionyl chloride cell evaluation

NASA Astrophysics Data System (ADS)

Zolla, A. E.; Waterhouse, R.; Debiccari, D.; Griffin, G. L.

1980-08-01

A test program was conducted to evaluate the Altus 1350AH cell performance against the Minuteman Survival Ground Power requirements. Twelve cells of the 17 inch diameter, 1-3/8 inch heights were fabricated and tested during this study. Under discharge rates varying from C/100 to C/400 at ambient temperature, the volumetric and gravimetric energy density performance requirements of 15 watt hours per cubic inch and 150 watt hours per pound were exceeded in all cases. All other performance requirements of voltage, current, configuration, capacity volume, weight, electrolyte leakage (none), and maintainability (none required), were met or exceeded. The abuse testing demonstrated the Altus Cell's ability to safely withstand short circuit by external shorting, short circuit by penetration with a conductive object, forced discharge, and forced charging of a cell. Disposal of discharged cells by incineration is an environmentally safe and efficient method of disposal.

Determination of thermal properties of commercial Ni-MH cells

NASA Astrophysics Data System (ADS)

Darcy, Eric C.

1994-02-01

The test objectives were to evaluate the electrical and thermal performance of commercial Ni-MH cells, evaluate the effectiveness of commercial charge control circuits, assess the abuse tolerance of these cells, and correlate performance and abuse tolerances to cell design via disassembly. Design objectives were to determine which cell designs are most suitable for scale-up and to guide the design of future shuttle and space station based battery chargers. Results, displayed in viewgraph format, include: reflex charging with ICS circuit resulted in premature charge termination; Ni-MH cells appear very tolerant to overcharge at low rates; Enstore's charger is more electrically and thermally efficient at high rates; and Ni-MH cycles much more efficiently than Ni-Cd with the delta-V/delta-t termination.

Determination of thermal properties of commercial Ni-MH cells

NASA Technical Reports Server (NTRS)

Darcy, Eric C.

1994-01-01

The test objectives were to evaluate the electrical and thermal performance of commercial Ni-MH cells, evaluate the effectiveness of commercial charge control circuits, assess the abuse tolerance of these cells, and correlate performance and abuse tolerances to cell design via disassembly. Design objectives were to determine which cell designs are most suitable for scale-up and to guide the design of future shuttle and space station based battery chargers. Results, displayed in viewgraph format, include: reflex charging with ICS circuit resulted in premature charge termination; Ni-MH cells appear very tolerant to overcharge at low rates; Enstore's charger is more electrically and thermally efficient at high rates; and Ni-MH cycles much more efficiently than Ni-Cd with the delta-V/delta-t termination.

A novel measure and significance testing in data analysis of cell image segmentation.

PubMed

Wu, Jin Chu; Halter, Michael; Kacker, Raghu N; Elliott, John T; Plant, Anne L

2017-03-14

Cell image segmentation (CIS) is an essential part of quantitative imaging of biological cells. Designing a performance measure and conducting significance testing are critical for evaluating and comparing the CIS algorithms for image-based cell assays in cytometry. Many measures and methods have been proposed and implemented to evaluate segmentation methods. However, computing the standard errors (SE) of the measures and their correlation coefficient is not described, and thus the statistical significance of performance differences between CIS algorithms cannot be assessed. We propose the total error rate (TER), a novel performance measure for segmenting all cells in the supervised evaluation. The TER statistically aggregates all misclassification error rates (MER) by taking cell sizes as weights. The MERs are for segmenting each single cell in the population. The TER is fully supported by the pairwise comparisons of MERs using 106 manually segmented ground-truth cells with different sizes and seven CIS algorithms taken from ImageJ. Further, the SE and 95% confidence interval (CI) of TER are computed based on the SE of MER that is calculated using the bootstrap method. An algorithm for computing the correlation coefficient of TERs between two CIS algorithms is also provided. Hence, the 95% CI error bars can be used to classify CIS algorithms. The SEs of TERs and their correlation coefficient can be employed to conduct the hypothesis testing, while the CIs overlap, to determine the statistical significance of the performance differences between CIS algorithms. A novel measure TER of CIS is proposed. The TER's SEs and correlation coefficient are computed. Thereafter, CIS algorithms can be evaluated and compared statistically by conducting the significance testing.

Silicon solar cell process. Development, fabrication and analysis

NASA Technical Reports Server (NTRS)

Yoo, H. I.; Iles, P. A.; Tanner, D. P.

1978-01-01

Solar cells were fabricated from unconventional silicon sheets, and the performances were characterized with an emphasis on statistical evaluation. A number of solar cell fabrication processes were used and conversion efficiency was measured under AMO condition at 25 C. Silso solar cells using standard processing showed an average efficiency of about 9.6%. Solar cells with back surface field process showed about the same efficiency as the cells from standard process. Solar cells from grain boundary passivation process did not show any improvements in solar cell performance.

Properties and Performance Attributes of Novel Co-Extruded Polyolefin Battery Separator Materials. Part 1; Mechanical Properties

NASA Technical Reports Server (NTRS)

Baldwin, Richard S.; Guzik, Monica; Skierski, Michael

2011-01-01

As NASA prepares for its next era of manned spaceflight missions, advanced energy storage technologies are being developed and evaluated to address future mission needs and technical requirements and to provide new mission-enabling technologies. Cell-level components for advanced lithium-ion batteries possessing higher energy, more reliable performance and enhanced, inherent safety characteristics are actively under development within the NASA infrastructure. A key component for safe and reliable cell performance is the cell separator, which separates the two energetic electrodes and functions to prevent the occurrence of an internal short-circuit while enabling ionic transport. Recently, a new generation of co-extruded separator films has been developed by ExxonMobil Chemical and introduced into their battery separator product portfolio. Several grades of this new separator material have been evaluated with respect to dynamic mechanical properties and safety-related performance attributes. This paper presents the results of these evaluations in comparison to a current state-ofthe-practice separator material. The results are discussed with respect to potential opportunities to enhance the inherent safety characteristics and reliability of future, advanced lithium-ion cell chemistries.

Improved FCG-1 cell technology

NASA Astrophysics Data System (ADS)

Breault, R. D.; Congdon, J. V.; Coykendall, R. D.; Luoma, W. L.

1980-10-01

Fuel cell performance in the ribbed substrate cell configuration consistent with that projected for a commercial power plant is demonstrated. Tests were conducted on subscale cells and on two 20 cell stacks of 4.8 MW demonstrator size cell components. These tests evaluated cell stack materials, processes, components, and assembly configurations. The first task was to conduct a component development effort to introduce improvements in 3.7 square foot, ribbed substrate acid cell repeating parts which represented advances in performance, function, life, and lower cost for application in higher pressure and temperature power plants. Specific areas of change were the electrode substrate, catalyst, matrix, seals, separator plates, and coolers. Full sized ribbed substrate stack components incorporating more stable materials were evaluated at increased pressure (93 psia) and temperature (405 F) conditions. Two 20 cell stacks with a 3.7 square feet, ribbed substrate cell configuration were tested.

Enabling High-Energy, High-Voltage Lithium-Ion Cells: Standardization of Coin-Cell Assembly, Electrochemical Testing, and Evaluation of Full Cells

DOE PAGES

Long, Brandon R.; Rinaldo, Steven G.; Gallagher, Kevin G.; ...

2016-11-09

Coin-cells are often the test format of choice for laboratories engaged in battery research and development as they provide a convenient platform for rapid testing of new materials on a small scale. However, reliable, reproducible data via the coin-cell format is inherently difficult, particularly in the full-cell configuration. In addition, statistical evaluation to prove the consistency and reliability of such data is often neglected. Herein we report on several studies aimed at formalizing physical process parameters and coin-cell construction related to full cells. Statistical analysis and performance benchmarking approaches are advocated as a means to more confidently track changes inmore » cell performance. Finally, we show that trends in the electrochemical data obtained from coin-cells can be reliable and informative when standardized approaches are implemented in a consistent manner.« less

Evaluating methods of inferring gene regulatory networks highlights their lack of performance for single cell gene expression data.

PubMed

Chen, Shuonan; Mar, Jessica C

2018-06-19

A fundamental fact in biology states that genes do not operate in isolation, and yet, methods that infer regulatory networks for single cell gene expression data have been slow to emerge. With single cell sequencing methods now becoming accessible, general network inference algorithms that were initially developed for data collected from bulk samples may not be suitable for single cells. Meanwhile, although methods that are specific for single cell data are now emerging, whether they have improved performance over general methods is unknown. In this study, we evaluate the applicability of five general methods and three single cell methods for inferring gene regulatory networks from both experimental single cell gene expression data and in silico simulated data. Standard evaluation metrics using ROC curves and Precision-Recall curves against reference sets sourced from the literature demonstrated that most of the methods performed poorly when they were applied to either experimental single cell data, or simulated single cell data, which demonstrates their lack of performance for this task. Using default settings, network methods were applied to the same datasets. Comparisons of the learned networks highlighted the uniqueness of some predicted edges for each method. The fact that different methods infer networks that vary substantially reflects the underlying mathematical rationale and assumptions that distinguish network methods from each other. This study provides a comprehensive evaluation of network modeling algorithms applied to experimental single cell gene expression data and in silico simulated datasets where the network structure is known. Comparisons demonstrate that most of these assessed network methods are not able to predict network structures from single cell expression data accurately, even if they are specifically developed for single cell methods. Also, single cell methods, which usually depend on more elaborative algorithms, in general have less similarity to each other in the sets of edges detected. The results from this study emphasize the importance for developing more accurate optimized network modeling methods that are compatible for single cell data. Newly-developed single cell methods may uniquely capture particular features of potential gene-gene relationships, and caution should be taken when we interpret these results.

Implications of electronic short circuiting in plasma sprayed solid oxide fuel cells on electrode performance evaluation by electrochemical impedance spectroscopy

NASA Astrophysics Data System (ADS)

White, B. D.; Kesler, O.

Electronic short circuiting of the electrolyte in a solid oxide fuel cell (SOFC) arising from flaws in the plasma spray fabrication process has been found to have a significant effect on the perceived performance of the electrodes, as evaluated by electrochemical impedance spectroscopy (EIS). The presence of a short circuit has been found to lead to the underestimation of the electrode polarization resistance (R p) and hence an overestimation of electrode performance. The effect is particularly noticeable when electrolyte resistance is relatively high, for example during low to intermediate temperature operation, leading to an obvious deviation from the expected Arrhenius-type temperature dependence of R p. A method is developed for determining the real electrode performance from measurements of various cell properties, and strategies for eliminating the occurrence of short circuiting in plasma sprayed cells are identified.

Qualification testing of secondary sterilizable silver-zinc cells for use in the Jupiter atmospheric entry probe

NASA Technical Reports Server (NTRS)

Manzo, M. A.

1981-01-01

A series of qualification tests were run on the secondary, sterilizable silver oxide - zinc cell developed at the NASA Lewis Research Center to determine if the cell was capable of providing mission power requirements for the Jupiter atmospheric entry probe. The cells were tested for their ability to survive radiation at the levels predicted for the Jovian atmosphere with no loss of performance. Cell performance was evaluated under various temperature and loading conditions, and the cells were tested under various environmental conditions related to launch and to deceleration into the Jovian atmosphere. The cell performed acceptably except under the required loading at low temperatures. The cell was redesigned to improve low-temperature performance and energy density. The modified cells improved performance at all temperatures. Results of testing cells of both the original and modified designs are discussed.

Monte Carlo dose calculation using a cell processor based PlayStation 3 system

NASA Astrophysics Data System (ADS)

Chow, James C. L.; Lam, Phil; Jaffray, David A.

2012-02-01

This study investigates the performance of the EGSnrc computer code coupled with a Cell-based hardware in Monte Carlo simulation of radiation dose in radiotherapy. Performance evaluations of two processor-intensive functions namely, HOWNEAR and RANMAR_GET in the EGSnrc code were carried out basing on the 20-80 rule (Pareto principle). The execution speeds of the two functions were measured by the profiler gprof specifying the number of executions and total time spent on the functions. A testing architecture designed for Cell processor was implemented in the evaluation using a PlayStation3 (PS3) system. The evaluation results show that the algorithms examined are readily parallelizable on the Cell platform, provided that an architectural change of the EGSnrc was made. However, as the EGSnrc performance was limited by the PowerPC Processing Element in the PS3, PC coupled with graphics processing units or GPCPU may provide a more viable avenue for acceleration.

Improvements in safety testing of lithium cells

NASA Astrophysics Data System (ADS)

Stinebring, R. C.; Krehl, P.

1985-07-01

A systematic approach was developed for evaluating the basic safety parameters of high power lithium soluble cathode cells. This approach consists of performing a series of tests on each cell model during the design, prototype and production phases. Abusive testing is performed in a facility where maximum protection is given to test personnel.

Improvements in safety testing of lithium cells

NASA Technical Reports Server (NTRS)

Stinebring, R. C.; Krehl, P.

1985-01-01

A systematic approach was developed for evaluating the basic safety parameters of high power lithium soluble cathode cells. This approach consists of performing a series of tests on each cell model during the design, prototype and production phases. Abusive testing is performed in a facility where maximum protection is given to test personnel.

Performance and Safety Tests on Samsung 18650 Li-ion Cells with Two Capacities

NASA Technical Reports Server (NTRS)

Deng, Yi; Jeevarajan, Judith; Rehm, Raymond; Bragg, Bobby; Zhang, Wenlin

2001-01-01

In order to meet the applications for Space Shuttle in the future, Samsung 18650 cylindrical Li-ion cells with two different capacities have been evaluated. The capacities are 1800 mAh, and 2000 mAh. The studies focused on the performance and safety tests of the cells.

An Update on the Lithium-Ion Cell Low-Earth-Orbit Verification Test Program

NASA Technical Reports Server (NTRS)

Reid, Concha M.; Manzo, Michelle A.; Miller, Thomas B.; McKissock, Barbara I.; Bennett, William

2007-01-01

A Lithium-Ion Cell Low-Earth-Orbit Verification Test Program is being conducted by NASA Glenn Research Center to assess the performance of lithium-ion (Li-ion) cells over a wide range of low-Earth-orbit (LEO) conditions. The data generated will be used to build an empirical model for Li-ion batteries. The goal of the modeling will be to develop a tool to predict the performance and cycle life of Li-ion batteries operating at a specified set of mission conditions. Using this tool, mission planners will be able to design operation points of the battery system while factoring in mission requirements and the expected life and performance of the batteries. Test conditions for the program were selected via a statistical design of experiments to span a range of feasible operational conditions for LEO aerospace applications. The variables under evaluation are temperature, depth-of-discharge (DOD), and end-of-charge voltage (EOCV). The baseline matrix was formed by generating combinations from a set of three values for each variable. Temperature values are 10 C, 20 C and 30 C. Depth-of-discharge values are 20%, 30% and 40%. EOCV values are 3.85 V, 3.95 V, and 4.05 V. Test conditions for individual cells may vary slightly from the baseline test matrix depending upon the cell manufacturer s recommended operating conditions. Cells from each vendor are being evaluated at each of ten sets of test conditions. Cells from four cell manufacturers are undergoing life cycle tests. Life cycling on the first sets of cells began in September 2004. These cells consist of Saft 40 ampere-hour (Ah) cells and Lith ion 30 Ah cells. These cells have achieved over 10,000 cycles each, equivalent to about 20 months in LEO. In the past year, the test program has expanded to include the evaluation of Mine Safety Appliances (MSA) 50 Ah cells and ABSL battery modules. The MSA cells will begin life cycling in October 2006. The ABSL battery modules consist of commercial Sony hard carbon 18650 lithium-ion cells configured in series and parallel combinations to create nominal 14.4 volt, 3 Ah packs (4s-2p). These modules have accumulated approximately 3000 cycles. Results on the performance of the cells and modules will be presented in this paper. The life prediction and performance model for Li-ion cells in LEO will be built by analyzing the data statistically and performing regression analysis. Cells are being cycled to failure so that differences in performance trends that occur at different stages in the life of the cell can be observed and accurately modeled. Cell testing is being performed at the Naval Surface Warfare Center in Crane, IN.

Laboratory evaluation of advanced battery technologies for electric vehicle applications

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Kulaga, J. E.; Hogrefe, R. L.; Tummilo, A. F.; Webster, C. E.

1989-03-01

During 1988, battery technology evaluations were performed for the Department of Energy and Electric Power Research Institute at the Argonne Analysis and Diagnostic Laboratory. Cells and multicell modules from four developers were examined to determine their performance and life characteristics for electric vehicle propulsion applications. The results provide an interim measure of the progress being made in battery R and D programs, a comparison of battery technologies, and a source of basic data for modeling and continuing R and D. This paper summarizes the performance and life characterizations of twelve single cells and six 3- to 24-cell modules that encompass four technologies (Na/S, Ni/Fe, lead-acid, and Fe/Air).

Evaluation of the maintenance of stemness, viability, and differentiation potential of gingiva-derived stem-cell spheroids.

PubMed

Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2017-05-01

Gingiva-derived stem cells have been applied for tissue-engineering purposes and may be considered a favorable source of mesenchymal stem cells as harvesting stem cells from the mandible or maxilla may be performed with ease under local anesthesia. The present study was performed to fabricate stem-cell spheroids using concave microwells and to evaluate the maintenance of stemness, viability, and differentiation potential. Gingiva-derived stem cells were isolated, and the stem cells of 4×10 5 (group A) or 8×10 5 (group B) cells were seeded into polydimethylsiloxane-based, concave micromolds with 600 µm diameters. The morphology of the microspheres and the change of the diameters of the spheroids were evaluated. The viability of spheroids was qualitatively analyzed via Live/Dead kit assay. A cell viability analysis was performed on days 1, 3, 6, and 12 with Cell Counting Kit-8. The maintenance of stemness was evaluated with immunocytochemical staining using SSEA-4, TRA-1-60(R) (positive markers), and SSEA-1 (negative marker). Osteogenic, adipogenic, and chondrogenic differentiation potential was evaluated by incubating spheroids in osteogenic, adipogenic and chondrogenic induction medium, respectively. The gingiva-derived stem cells formed spheroids in the concave microwells. The diameters of the spheroids were larger in group A than in group B. The majority of cells in the spheroids emitted green fluorescence, indicating the presence of live cells at day 6. At day 12, the majority of cells in the spheroids emitted green fluorescence, and a small portion of red fluorescence was also noted, which indicated the presence of dead cells. The spheroids were positive for the stem-cell markers SSEA-4 and TRA-1-60(R) and were negative for SSEA-1, suggesting that these spheroids primarily contained undifferentiated human stem cells. Osteogenic, adipogenic, and chondrogenic differentiation was more evident with an increase of incubation time: Mineralized extracellular deposits were observed following Alizarin Red S staining at days 14 and 21; oil globules were increased at day 18 when compared with day 6; and Alcian blue staining was more evident at day 18 when compared with day 6. Within the limits of this study, stem-cell spheroids from gingival cells maintained the stemness, viability, and differentiation potential during the experimental periods. This method may be applied for a promising strategy for stem-cell therapy.

Capacity Loss Studies on High Capacity Li-ion Cells for the Orbiter Advanced Hydraulic Power System

NASA Technical Reports Server (NTRS)

Jeevarajan, Judith A.; Irlbeck, Bradley W.

2004-01-01

Contents include the following: Introduction. Physical and electrochemical characteristics. Performance evaluation. Rate performance. Internal resistance. Performance at different temperatures. Safety evaluation. Overcharge. Overdischarge. External short. Simulated internal short. Heat-to-vent. Vibration. Drop rest. Vent and burst pressure.

Performance and Safety of Lithium Ion Cells

NASA Technical Reports Server (NTRS)

Ratnakumar, B. V.; Smart, M. C.; Whitcanack, L.; Surampudi, S.; Marsh, R.

2001-01-01

This report evaluates the performance and safety of Lithium Ion (Li-Ion) cells when used in batteries. Issues discussed include the cycle life, energy efficiency, tolerance to higher charge voltage, tolerance to extended tapered charge voltage, charge on cycling, specific energy, low temperature discharge, low temperature charge, various charge characteristics, storage characteristics, and more of Li-Ion cells.

Evaluation and Testing of Commercially-Available Carbon Nanotubes as Negative Electrodes for Lithium Ion Cells

NASA Technical Reports Server (NTRS)

Britton, Doris L.

2007-01-01

Rechargeable lithium ion (Li-ion) battery technology offers significant performance advantages over the nickel-based technologies used for energy storage for the majority of NASA's missions. Specifically Li-ion technology offers a threefold to fourfold increase in gravimetric and volumetric energy densities and produces voltages in excess of three times the value of typical nickel-based battery systems. As part of the Advanced Battery Technology program at NASA Glenn Research Center (GRC), a program on the evaluation of anodes for Li-ion cells and batteries was conducted. This study focused on the feasibility of using carbon nanotubes as anodes in Li-Ion cells. Candidate materials from multiple sources were evaluated. Their performance was compared to a standard anode comprised of mesocarbon microbeads. In all cases, the standard MCMB electrode exhibited superior performance. The details and results of the study are presented.

Construction of Gallium Point at NMIJ

NASA Astrophysics Data System (ADS)

Widiatmo, J. V.; Saito, I.; Yamazawa, K.

2017-03-01

Two open-type gallium point cells were fabricated using ingots whose nominal purities are 7N. Measurement systems for the realization of the melting point of gallium using these cells were built. The melting point of gallium is repeatedly realized by means of the measurement systems for evaluating the repeatability. Measurements for evaluating the effect of hydrostatic pressure coming from the molten gallium existing during the melting process and the effect of gas pressure that fills the cell were also performed. Direct cell comparisons between those cells were conducted. This comparison was aimed to evaluate the consistency of each cell, especially related to the nominal purity. Direct cell comparison between the open-type and the sealed-type gallium point cell was also conducted. Chemical analysis was conducted using samples extracted from ingots used in both the newly built open-type gallium point cells, from which the effect of impurities in the ingot was evaluated.

Improved Electrodes for High Temperature Proton Exchange Membrane Fuel Cells using Carbon Nanospheres.

PubMed

Zamora, Héctor; Plaza, Jorge; Cañizares, Pablo; Lobato, Justo; Rodrigo, Manuel A

2016-05-23

This work evaluates the use of carbon nanospheres (CNS) in microporous layers (MPL) of high temperature proton exchange membrane fuel cell (HT-PEMFC) electrodes and compares the characteristics and performance with those obtained using conventional MPL based on carbon black. XRD, hydrophobicity, Brunauer-Emmett-Teller theory, and gas permeability of MPL prepared with CNS were the parameters evaluated. In addition, a short life test in a fuel cell was carried out to evaluate performance under accelerated stress conditions. The results demonstrate that CNS is a promising alternative to traditional carbonaceous materials because of its high electrochemical stability and good electrical conductivity, suitable to be used in this technology. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Using simulated fluorescence cell micrographs for the evaluation of cell image segmentation algorithms.

PubMed

Wiesmann, Veit; Bergler, Matthias; Palmisano, Ralf; Prinzen, Martin; Franz, Daniela; Wittenberg, Thomas

2017-03-18

Manual assessment and evaluation of fluorescent micrograph cell experiments is time-consuming and tedious. Automated segmentation pipelines can ensure efficient and reproducible evaluation and analysis with constant high quality for all images of an experiment. Such cell segmentation approaches are usually validated and rated in comparison to manually annotated micrographs. Nevertheless, manual annotations are prone to errors and display inter- and intra-observer variability which influence the validation results of automated cell segmentation pipelines. We present a new approach to simulate fluorescent cell micrographs that provides an objective ground truth for the validation of cell segmentation methods. The cell simulation was evaluated twofold: (1) An expert observer study shows that the proposed approach generates realistic fluorescent cell micrograph simulations. (2) An automated segmentation pipeline on the simulated fluorescent cell micrographs reproduces segmentation performances of that pipeline on real fluorescent cell micrographs. The proposed simulation approach produces realistic fluorescent cell micrographs with corresponding ground truth. The simulated data is suited to evaluate image segmentation pipelines more efficiently and reproducibly than it is possible on manually annotated real micrographs.

Chronic treadmill exercise in rats delicately alters the Purkinje cell structure to improve motor performance and toxin resistance in the cerebellum.

PubMed

Huang, Tung-Yi; Lin, Lung-Sheng; Cho, Keng-Chi; Chen, Shean-Jen; Kuo, Yu-Min; Yu, Lung; Wu, Fong-Sen; Chuang, Jih-Ing; Chen, Hsiun-Ing; Jen, Chauying J

2012-09-01

Although exercise usually improves motor performance, the underlying cellular changes in the cerebellum remain to be elucidated. This study aimed to investigate whether and how chronic treadmill exercise in young rats induced Purkinje cell changes to improve motor performance and rendered the cerebellum less vulnerable to toxin insults. After 1-wk familiarization of treadmill running, 6-wk-old male Wistar rats were divided into exercise and sedentary groups. The exercise group was then subjected to 8 wk of exercise training at moderate intensity. The rotarod test was carried out to evaluate motor performance. Purkinje cells in cerebellar slices were visualized by lucifer yellow labeling in single neurons and by calbindin immunostaining in groups of neurons. Compared with sedentary control rats, exercised rats not only performed better in the rotarod task, but also showed finer Purkinje cell structure (higher dendritic volume and spine density with the same dendritic field). The exercise-improved cerebellar functions were further evaluated by monitoring the long-lasting effects of intraventricular application of OX7-saporin. In the sedentary group, OX7-saporin treatment retarded the rotarod performance and induced ∼60% Purkinje cell loss in 3 wk. As a comparison, the exercise group showed much milder injuries in the cerebellum by the same toxin treatment. In conclusion, exercise training in young rats increased the dendritic density of Purkinje cells, which might play an important role in improving the motor performance. Furthermore, as Purkinje cells in the exercise group were relatively toxin resistant, the exercised rats showed good motor performance, even under toxin-treated conditions.

Solid Polymer Electrolyte (SPE) fuel cell technology program

NASA Technical Reports Server (NTRS)

1978-01-01

Many previously demonstrated improved fuel cell features were consolidated to (1) obtain a better understanding of the observed characteristics of the operating laboratory-sized cells; (2) evaluate appropriate improved fuel cell features in 0.7 sq ft cell hardware; and (3) study the resultant fuel cell capability and determine its impact on various potential fuel cell space missions. The observed performance characteristics of the fuel cell at high temperatures and high current densities were matched with a theoretical model based on the change in Gibbs free energy voltage with respect to temperature and internal resistance change with current density. Excellent agreement between the observed and model performance was obtained. The observed performance decay with operational time on cells with very low noble metal loadings (0.05 mg/sq cm) were shown to be related to loss in surface area. Cells with the baseline amount of noble catalyst electrode loading demonstrated over 40,000 hours of stable performance.

Performance evaluation of multi-junction solar cells by spatially resolved electroluminescence microscopy.

PubMed

Kong, Lijing; Wu, Zhiming; Chen, Shanshan; Cao, Yiyan; Zhang, Yong; Li, Heng; Kang, Junyong

2015-01-01

An electroluminescence microscopy combined with a spectroscopy was developed to visually analyze multi-junction solar cells. Triple-junction solar cells with different conversion efficiencies were characterized by using this system. The results showed that the mechanical damages and material defects in solar cells can be clearly distinguished, indicating a high-resolution imaging. The external quantum efficiency (EQE) measurements demonstrated that different types of defects or damages impacted cell performance in various degrees and the electric leakage mostly degraded the EQE. Meanwhile, we analyzed the relationship between electroluminescence intensity and short-circuit current density J SC. The results indicated that the gray value of the electroluminescence image corresponding to the intensity was almost proportional to J SC. This technology provides a potential way to evaluate the current matching status of multi-junction solar cells.

Performance evaluation of advanced battery technologies for electric vehicle applications

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Tummillo, A. F.; Kulaga, J. E.; Webster, C. E.; Gillie, K. R.; Hogrefe, R. L.

1990-01-01

At the Argonne Analysis and Diagnostic Laboratory, advanced battery technology evaluations are performed under simulated electric vehicle operating conditions. During 1989 and the first quarter of 1990, single cell and multicell modules from seven developers were examined for the Department of Energy and Electric Power Research Institute. The results provide battery users, developers, and program managers with an interim measure of the progress being made in battery R&D programs, a comparison of battery technologies, and a source of basic data for modeling and continuing R&D. This paper summarizes the performance and life characterizations of two single cells and seven 3- to 960-cell modules that encompass six technologies (Na/S, Ni/Fe, Ni/Cd, Ni-metal hydride, lead-acid, and Zn/Br).

Comparison of parameter-adapted segmentation methods for fluorescence micrographs.

PubMed

Held, Christian; Palmisano, Ralf; Häberle, Lothar; Hensel, Michael; Wittenberg, Thomas

2011-11-01

Interpreting images from fluorescence microscopy is often a time-consuming task with poor reproducibility. Various image processing routines that can help investigators evaluate the images are therefore useful. The critical aspect for a reliable automatic image analysis system is a robust segmentation algorithm that can perform accurate segmentation for different cell types. In this study, several image segmentation methods were therefore compared and evaluated in order to identify the most appropriate segmentation schemes that are usable with little new parameterization and robustly with different types of fluorescence-stained cells for various biological and biomedical tasks. The study investigated, compared, and enhanced four different methods for segmentation of cultured epithelial cells. The maximum-intensity linking (MIL) method, an improved MIL, a watershed method, and an improved watershed method based on morphological reconstruction were used. Three manually annotated datasets consisting of 261, 817, and 1,333 HeLa or L929 cells were used to compare the different algorithms. The comparisons and evaluations showed that the segmentation performance of methods based on the watershed transform was significantly superior to the performance of the MIL method. The results also indicate that using morphological opening by reconstruction can improve the segmentation of cells stained with a marker that exhibits the dotted surface of cells. Copyright © 2011 International Society for Advancement of Cytometry.

Characterization of three types of silicon solar cells for SEPS deep space missions. Volume 1: Current-voltage characteristics of OCLI BSF/BSR 10 ohm-cm, and BSR 2 ohm-cm cells as a function of temperature and intensity

NASA Technical Reports Server (NTRS)

Whitaker, A. F.; Little, S. A.; Smith, C. F., Jr.; Wooden, V. A.

1979-01-01

Three types of high performance silicon solar cells, BSF/BSR 10 ohm-cm, BSR 10 ohm-cm, and BSR 2 ohm-cm, were evaluated for their low temperature and low intensity performance. Sixteen cells of each type were subjected to ten temperatures and nine intensities. The BSF/BSR 10 ohm-cm cells provided the best performance at 1 solar constant and +25 C with an efficiency of 14.1% while the BSR 2 ohm-cm cells had the highest low temperature and low intensity performance with an efficiency of 22.2% at 0.04 solar constant and -170 C and the most consistent cell-to-cell characteristics.

Metrology for Fuel Cell Manufacturing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stocker, Michael; Stanfield, Eric

2015-02-04

The project was divided into three subprojects. The first subproject is Fuel Cell Manufacturing Variability and Its Impact on Performance. The objective was to determine if flow field channel dimensional variability has an impact on fuel cell performance. The second subproject is Non-contact Sensor Evaluation for Bipolar Plate Manufacturing Process Control and Smart Assembly of Fuel Cell Stacks. The objective was to enable cost reduction in the manufacture of fuel cell plates by providing a rapid non-contact measurement system for in-line process control. The third subproject is Optical Scatterfield Metrology for Online Catalyst Coating Inspection of PEM Soft Goods. Themore » objective was to evaluate the suitability of Optical Scatterfield Microscopy as a viable measurement tool for in situ process control of catalyst coatings.« less

Prostate Cancer Evaluation: Design, Synthesis and Evaluation of Novel Enzyme-Activated Proton MRI Contrast Agents

DTIC Science & Technology

2009-10-01

NUMBER E -Mail: 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER...transcriptional activation, protein expression, and protein interaction, lacZ gene encoding E . coli β-gal has already been recognized as the most...1) Cell preparation (a) Stably transfected PC3 cell line: E . coli lacZ gene (from pSV-β-gal vector, Promega, Madison,WI) was inserted into high

Orbiter fuel cell performance constraints. STS/OPS Pratt Whitney fuel cells. Operating limits for mission planning

NASA Technical Reports Server (NTRS)

Kolkhorst, H. E.

1980-01-01

The orbiter fuel cell powerplant (FCP) performance constraints listed in the Shuttle Operational Data Book (SODB) were analyzed using the shuttle environmental control requirements evaluation tool. The effects of FCP lifetime, coolant loops, and FCP voltage output were considered. Results indicate that the FCP limits defined in the SODB are not valid.

NASA Non-Flow-Through PEM Fuel Cell System for Aerospace Applications

NASA Technical Reports Server (NTRS)

Araghi, Koorosh R.

2011-01-01

NASA is researching passive NFT Proton Exchange Membrane (PEM) fuel cell technologies for primary fuel cell power plants in air-independent applications. NFT fuel cell power systems have a higher power density than flow through systems due to both reduced parasitic loads and lower system mass and volume. Reactant storage still dominates system mass/volume considerations. NFT fuel cell stack testing has demonstrated equivalent short term performance to flow through stacks. More testing is required to evaluate long-term performance.

Evaluation of fuel cell system efficiency and degradation at development and during commercialization

NASA Astrophysics Data System (ADS)

Gemmen, R. S.; Johnson, C. D.

Two primary parameters stand out for characterizing fuel cell system performance. The first and most important parameter is system efficiency. This parameter is relatively easy to define, and protocols for its assessment are already available. Another important parameter yet to be fully considered is system degradation. Degradation is important because customers desire to know how long their purchased fuel cell unit will last. The measure of degradation describes this performance factor by quantifying, for example, how the efficiency of the unit degrades over time. While both efficiency and degradation concepts are readily understood, the coupling between these two parameters must also be understood so that proper testing and evaluation of fuel cell systems is achieved. Tests not properly performed, and results not properly understood, may result in improper use of the evaluation data, producing improper R&D planning decisions and financial investments. This paper presents an analysis of system degradation, recommends an approach to its measurement, and shows how these two parameters are related and how one can be "traded-off" for the other.

Electrochemical Characterization of Carbon Nanotubes for Fuel Cell MEA's

NASA Technical Reports Server (NTRS)

Panagaris, Jael; Loyselle, Patricia

2004-01-01

Single-walled and multi-walled carbon nanotubes from different sources have been evaluated before and after sonication to identify structural differences and evaluate electrochemical performance. Raman spectral analysis and cyclic voltammetry in situ with QCM were the principle means of evaluating the tubes. The raman data indicates that sonication in toluene modifies the structural properties of the nanotubes. Sonication also affects the electrochemical performance of single-walled nanotubes and the multi-walled tubes differently. The characterization of different types of carbon nanotubes leads up to identifying a potential candidate for incorporating carbon nanotubes for fuel cell MEA structures.

Cell-NPE (Numerical Performance Evaluation): Programming the IBM Cell Broadband Engine -- A General Parallelization Strategy

DTIC Science & Technology

2008-04-01

Space GmbH as follows: B. TECHNICAL PRPOPOSA/DESCRIPTION OF WORK Cell: A Revolutionary High Performance Computing Platform On 29 June 2005 [1...IBM has announced that is has partnered with Mercury Computer Systems, a maker of specialized computers . The Cell chip provides massive floating-point...the computing industry away from the traditional processor technology dominated by Intel. While in the past, the development of computing power has

Segmentation of fluorescence microscopy cell images using unsupervised mining.

PubMed

Du, Xian; Dua, Sumeet

2010-05-28

The accurate measurement of cell and nuclei contours are critical for the sensitive and specific detection of changes in normal cells in several medical informatics disciplines. Within microscopy, this task is facilitated using fluorescence cell stains, and segmentation is often the first step in such approaches. Due to the complex nature of cell issues and problems inherent to microscopy, unsupervised mining approaches of clustering can be incorporated in the segmentation of cells. In this study, we have developed and evaluated the performance of multiple unsupervised data mining techniques in cell image segmentation. We adapt four distinctive, yet complementary, methods for unsupervised learning, including those based on k-means clustering, EM, Otsu's threshold, and GMAC. Validation measures are defined, and the performance of the techniques is evaluated both quantitatively and qualitatively using synthetic and recently published real data. Experimental results demonstrate that k-means, Otsu's threshold, and GMAC perform similarly, and have more precise segmentation results than EM. We report that EM has higher recall values and lower precision results from under-segmentation due to its Gaussian model assumption. We also demonstrate that these methods need spatial information to segment complex real cell images with a high degree of efficacy, as expected in many medical informatics applications.

Thermal stress cycling of GaAs solar cells

NASA Technical Reports Server (NTRS)

Francis, Robert W.

1987-01-01

Thermal stress cycling was performed on gallium arsenide solar cells to investigate their electrical, mechanical, and structural integrity. Cells were cycled under low Earth orbit (LEO) simulated temperature conditions in vacuum. Cell evaluations consisted of power output values, spectral response, optical microscopy and ion microprobe mass analysis, and depth profiles on both front surface inter-grid areas and metallization contact grid lines. Cells were examined for degradation after 500, 5,000, 10,000 and 15,245 thermal cycles. No indication of performance degradation was found for any vendor's cell lot.

Preliminary test results for Li-SOCl2 high-rate D cells

NASA Technical Reports Server (NTRS)

Bragg, Bobby J.; Johnson, Paul

1992-01-01

The performance and abuse characteristics of 55 D-size lithium-thionyl chloride (Li-SOCl2) cells are evaluated at relatively high rates. Results from the following tests are presented: shock test, vibration test, capacity performance, uninsulated short circuit, high temperature exposure, and overdischarge.

Preliminary test results for Li-SOCl2 high-rate D cells

NASA Astrophysics Data System (ADS)

Bragg, Bobby J.; Johnson, Paul

1992-02-01

The performance and abuse characteristics of 55 D-size lithium-thionyl chloride (Li-SOCl2) cells are evaluated at relatively high rates. Results from the following tests are presented: shock test, vibration test, capacity performance, uninsulated short circuit, high temperature exposure, and overdischarge.

RECOVERY OF DNA FROM SOILS AND SEDIMENTS

EPA Science Inventory

Experiments were performed to evaluate the effectiveness of different methodological approaches for recovering DNA from soil and sediment bacterial communities; cell extraction followed by lysis and DNA recovery (cell extraction method) versus direct cell lysis and alkaline extra...

Fundamentals of affinity cell separations.

PubMed

Zhang, Ye; Lyons, Veronica; Pappas, Dimitri

2018-03-01

Cell separations using affinity methods continue to be an enabling science for a wide variety of applications. In this review, we discuss the fundamental aspects of affinity separation, including the competing forces for cell capture and elution, cell-surface interactions, and models for cell adhesion. Factors affecting separation performance such as bond affinity, contact area, and temperature are presented. We also discuss and demonstrate the effects of nonspecific binding on separation performance. Metrics for evaluating cell separations are presented, along with methods of comparing separation techniques for cell isolation using affinity capture. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effect of Interface Cracks on the Electrical Performance of Solar Cells

NASA Astrophysics Data System (ADS)

Kim, Hansung; Tofail, Md. Towfiq; John, Ciby

2018-04-01

Among a variety of solar cell types, thin-film solar cells have been rigorously investigated as cost-effective and efficient solar cells. In many cases, flexible solar cells are also fabricated as thin films and undergo frequent stress due to the rolling and bending modes of applications. These frequent motions result in crack initiation and propagation (including delamination) in the thin-film solar cells, which cause degradation in efficiency. Reliability evaluation of solar cells is essential for developing a new type of solar cell. In this paper, we investigated the effect of layer delamination and grain boundary crack on 3D thin-film solar cells. We used finite element method simulation for modeling of both electrical performance and cracked structure of 3D solar cells. Through simulations, we quantitatively calculated the effect of delamination length on 3D copper indium gallium diselenide (CIGS) solar cell performance. Moreover, it was confirmed that the grain boundary of CIGS could improve the solar cell performance and that grain boundary cracks could decrease cell performance by altering the open circuit voltage. In this paper, the investigated material is a CIGS solar cell, but our method can be applied to general polycrystalline solar cells.

Sodium-sulfur technology evaluation at Argonne National Laboratory

NASA Astrophysics Data System (ADS)

Mulcahey, T. P.; Tummillo, A. F.; Hogrefe, R. L.; Christianson, C. C.; Biwer, R.; Webster, C. E.; Lee, J.; Miller, J. F.; Marr, J. J.; Smaga, J. A.

The Analysis and Diagnostics Laboratory (ADL) at Argonne National Laboratory has completed evaluation of the Ford Aerospace and Communication Corp. (FACC) technology in the form of four load-levelling (LL) cells, five electric vehicle (EV) cells, and a sub-battery of 89 series connected EV cells. The ADL also has initiated evaluation of the Chloride Silent Power Limited (CSPL) sodium-sulfur (PB) battery technology in the form of 8 individual cells. The evaluation of the FACC-LL cells consisted of an abbreviated performance characterization followed by life-cycle tests on two individual cells and life-cycle tests only on the two other individual cells. The evaluation indicated that the technology was improving, but long-term (life) reliability was not yet adequate for utility applications. The cells exhibited individual cycle lives ranging from 659 to over 1366 cycles, which is equivalent to 2 1/2 to 5 1/2 years in utility use. It was also found that full-cell capacity could only be maintained by applying a special charge regime, regularly or periodically, that consisted of a constant-current followed by a constant-voltage.

In-house fabrication and testing capabilities for Li and Li-ion 18650 cells

NASA Astrophysics Data System (ADS)

Nagasubramanian, G.

2010-04-01

For over 10 years Sandia Labs have been involved in an US DOE-funded program aimed at developing electric vehicle batteries for transportation applications. Currently this program is called "Advanced Battery Research (ABR)." In this effort we were preparing 18650 cells with electrodes supplied by or purchased from private companies for thermal abuse and electrical characterization studies. Lately, we are coating our own electrodes, building cells and evaluating performance. This paper describes our extensive in-house facilities for slurry making, electrode coating, cell winding etc. In addition, facilities for electrical testing and thermal abuse will be described. This facility allows us to readjust our focus quickly to the changing demands of the still evolving ABR program. Additionally, we continue to make cells for our internal use. We made several 18650 cells both primary (Li-CFx) and secondary (Li-ion) and evaluated performance. For example Li-CFx cells gave ~2.9Ahr capacity at room temperature. Our high voltage Li-ion cells consisting of carbon anode and cathode based on LiNi 0.4Mn 0.3Co 0.3O2 in organic electrolytes exhibited reproducible behavior and gave capacity on the order of 1Ahr. Performance of Li-ion cells at different temperatures and thermal abuse characteristics will be presented.

A Prospective Evaluation of Circulating Tumor Cells and Cell-Free DNA in EGFR-Mutant Non-Small Cell Lung Cancer Patients Treated with Erlotinib on a Phase II Trial.

PubMed

Yanagita, Masahiko; Redig, Amanda J; Paweletz, Cloud P; Dahlberg, Suzanne E; O'Connell, Allison; Feeney, Nora; Taibi, Myriam; Boucher, David; Oxnard, Geoffrey R; Johnson, Bruce E; Costa, Daniel B; Jackman, David M; Jänne, Pasi A

2016-12-15

Genotype-directed therapy is the standard of care for advanced non-small cell lung cancer (NSCLC), but obtaining tumor tissue for genotyping remains a challenge. Circulating tumor cell (CTC) or cell-free DNA (cfDNA) analysis may allow for noninvasive evaluation. This prospective trial evaluated CTCs and cfDNA in EGFR-mutant NSCLC patients treated with erlotinib until progression. EGFR-mutant NSCLC patients were enrolled in a phase II trial of erlotinib. Blood was collected at baseline, every 2 months on study, and at disease progression. Plasma genotyping was performed by droplet digital PCR for EGFR19del, L858R, and T790M. CTCs were isolated by CellSave, enumerated, and analyzed by immunofluorescence for CD45 and pan-cytokeratin and EGFR and MET FISH were also performed. Rebiopsy was performed at disease progression. Sixty patients were enrolled; 44 patients discontinued therapy for disease progression. Rebiopsy occurred in 35 of 44 patients (80%), with paired CTC/cfDNA analysis in 41 of 44 samples at baseline and 36 of 44 samples at progression. T790M was identified in 23 of 35 (66%) tissue biopsies and 9 of 39 (23%) cfDNA samples. CTC analysis at progression identified MET amplification in 3 samples in which tissue analysis could not be performed. cfDNA analysis identified T790M in 2 samples in which rebiopsy was not possible. At diagnosis, high levels of cfDNA but not high levels of CTCs correlated with progression-free survival. cfDNA and CTCs are complementary, noninvasive assays for evaluation of acquired resistance to first-line EGFR TKIs and may expand the number of patients in whom actionable genetic information can be obtained at acquired resistance. Serial cfDNA monitoring may offer greater clinical utility than serial monitoring of CTCs. Clin Cancer Res; 22(24); 6010-20. ©2016 AACR. ©2016 American Association for Cancer Research.

Development of inexpensive metal macrocyclic complexes for use in fuel cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doddapaneni, N.; Ingersoll, D.; Kosek, J.A.

Several metal macrocyclic complexes were synthesized for use as catalysts in fuel cells. An initial evaluation of their ability to catalyze the fuel cell reactions were completed. Based on this initial evaluation, one metal macrocyclic catalyst was selected and long-term stability testing in a fuel cell was initiated. The fuel cell employing this catalyst was operated continuously for one year with little signs of catalyst degradation. The effect of synthetic reformates on the performance of the catalyst in the fuel cell environment also demonstrated high tolerance of this catalyst for common contaminants and poisons.

Continuous Non-Destructive Monitoring of Cell Health Using Impedance Based Interdigitated Electrode Structured Sensors

NASA Astrophysics Data System (ADS)

Paschero, Anna; McLoughlin, Eve; Moore, Eric

2011-06-01

This article examines some preliminary tests which were performed in order to evaluate the best electrode configuration (width and spacing) for cell culture analyses. Biochips packaged with indium tin oxide (ITO) interdigitated electrodes (IDEs) were used to perform impedance measurements on A549 cells cultured on the surface of the biochip. Several tests were carried out using a 10 mM solution of Sodium Chloride (NaCl), cell medium and the cell culture itself to characterize some of the configurations already fabricated in the facilities at Tyndall National Institute.

Hydrogen-bromine fuel cell advance component development

NASA Technical Reports Server (NTRS)

Charleston, Joann; Reed, James

1988-01-01

Advanced cell component development is performed by NASA Lewis to achieve improved performance and longer life for the hydrogen-bromine fuel cells system. The state-of-the-art hydrogen-bromine system utilizes the solid polymer electrolyte (SPE) technology, similar to the SPE technology developed for the hydrogen-oxygen fuel cell system. These studies are directed at exploring the potential for this system by assessing and evaluating various types of materials for cell parts and electrode materials for Bromine-hydrogen bromine environment and fabricating experimental membrane/electrode-catalysts by chemical deposition.

Power source evaluation capabilities at Sandia National Laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doughty, D.H.; Butler, P.C.

1996-04-01

Sandia National Laboratories maintains one of the most comprehensive power source characterization facilities in the U.S. National Laboratory system. This paper describes the capabilities for evaluation of fuel cell technologies. The facility has a rechargeable battery test laboratory and a test area for performing nondestructive and functional computer-controlled testing of cells and batteries.

Evaluation of single and stack membraneless enzymatic fuel cells based on ethanol in simulated body fluids.

PubMed

Galindo-de-la-Rosa, J; Arjona, N; Moreno-Zuria, A; Ortiz-Ortega, E; Guerra-Balcázar, M; Ledesma-García, J; Arriaga, L G

2017-06-15

The purpose of this work is to evaluate single and double-cell membraneless microfluidic fuel cells (MMFCs) that operate in the presence of simulated body fluids SBF, human serum and blood enriched with ethanol as fuels. The study was performed using the alcohol dehydrogenase enzyme immobilised by covalent binding through an array composed of carbon Toray paper as support and a layer of poly(methylene blue)/tetrabutylammonium bromide/Nafion and glutaraldehyde (3D bioanode electrode). The single MMFC was tested in a hybrid microfluidic fuel cell using Pt/C as the cathode. A cell voltage of 1.035V and power density of 3.154mWcm -2 were observed, which is the highest performance reported to date. The stability and durability were tested through chronoamperometry and polarisation/performance curves obtained at different days, which demonstrated a slow decrease in the power density on day 10 (14%) and day 20 (26%). Additionally, the cell was tested for ethanol oxidation in simulated body fluid (SBF) with ionic composition similar to human blood plasma. Those tests resulted in 0.93V of cell voltage and a power density close to 1.237mWcm -2 . The double cell MMFC (Stack) was tested using serum and human blood enriched with ethanol. The stack operated with blood in a serial connection showed an excellent cell performance (0.716mWcm -2 ), demonstrating the feasibility of employing human blood as energy source. Copyright © 2017 Elsevier B.V. All rights reserved.

Battery testing at Argonne National Laboratory

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

Advanced battery technology evaluations are performed under simulated electric-vehicle operating conditions at the Analysis & Diagnostic Laboratory (ADL) of Argonne National Laboratory. The ADL results provide insight into those factors that limit battery performance and life. The ADL facilities include a test laboratory to conduct battery experimental evaluations under simulated application conditions and a post-test analysis laboratory to determine, in a protected atmosphere if needed, component compositional changes and failure mechanisms. This paper summarizes the performance characterizations and life evaluations conducted during FY-92 on both single cells and multi-cell modules that encompass six battery technologies (Na/S, Li/FeS, Ni/Metal-Hydride, Ni/Zn, Ni/Cd, Ni/Fe). These evaluations were performed for the Department of Energy, Office of Transportation Technologies, Electric and Hybrid Propulsion Division, and the Electric Power Research Institute. The ADL provides a common basis for battery performance characterization and life evaluations with unbiased application of tests and analyses. The results help identify the most promising R&D approaches for overcoming battery limitations, and provide battery users, developers, and program managers with a measure of the progress being made in battery R&D programs, a comparison of battery technologies, and basic data for modeling.

Thermal analysis of a multi-layer microchannel heat sink for cooling concentrator photovoltaic (CPV) cells

NASA Astrophysics Data System (ADS)

Siyabi, Idris Al; Shanks, Katie; Mallick, Tapas; Sundaram, Senthilarasu

2017-09-01

Concentrator Photovoltaic (CPV) technology is increasingly being considered as an alternative option for solar electricity generation. However, increasing the light concentration ratio could decrease the system output power due to the increase in the temperature of the cells. The performance of a multi-layer microchannel heat sink configuration was evaluated using numerical analysis. In this analysis, three dimensional incompressible laminar steady flow model was solved numerically. An electrical and thermal solar cell model was coupled for solar cell temperature and efficiency calculations. Thermal resistance, solar cell temperature and pumping power were used for the system efficiency evaluation. An increase in the number of microchannel layers exhibited the best overall performance in terms of the thermal resistance, solar cell temperature uniformity and pressure drop. The channel height and width has no effect on the solar cell maximum temperature. However, increasing channel height leads to a reduction in the pressure drop and hence less fluid pumping power.

Results of the 1980 NASA/JPL balloon flight solar cell calibration program

NASA Technical Reports Server (NTRS)

Seaman, C. H.; Weiss, R. S.

1981-01-01

Thirty-eight modules were carried to an altitude of about 36 kilometers. In addition to the cell calibration program, an experiment to evaluate the calibration error versus altitude was performed. The calibrated cells can be used as reference standards in simulator testing of cells and arrays.

Assessment of cytologic evaluation of preputial epithelial cells as a diagnostic test for detection of adrenocortical disease in castrated ferrets.

PubMed

Protain, Holly J; Kutzler, Michelle A; Valentine, Beth A

2009-05-01

To determine whether results of cytologic evaluation of preputial epithelial cells correspond to results of a serum endocrine hormone assay and clinical signs associated with adrenocortical disease in castrated ferrets. 13 clinically normal ferrets and 8 ferrets with signs of adrenocortical disease. Blood and preputial lavage samples were collected from each ferret. Serum samples were submitted to the University of Tennessee Veterinary Diagnostic Laboratory for performance of an endocrine hormone assay. Differential epithelial cell counts were performed on preputial lavage samples to determine the percentage of cornified cells. Results of cytologic evaluation were compared with results of the endocrine hormone assay and clinical status of ferrets. The percentage of cornified preputial epithelial cells was not significantly correlated with serum 17B-estradiol or androstenedione concentration but was significantly correlated with serum 17-hydroxyprogesterone concentration (r = 0.60). The percentage of cornified preputial epithelial cells was higher in ferrets with clinical signs of adrenocortical disease (mean +/- SD, 71.3 +/- 16.9%) than in clinically normal ferrets (55.5 +/- 19.0%). Cornification of preputial epithelial cells was correlated with an increase in serum 17-hydroxyprogesterone concentration as well as clinical signs of adrenocortical disease in castrated ferrets. Additional investigation is needed to elucidate the mechanism of preputial epithelial cell cornification in castrated ferrets.

Performance evaluation of thermophotovoltaic GaSb cell technology in high temperature waste heat

NASA Astrophysics Data System (ADS)

Utlu, Z.; Önal, B. S.

2018-02-01

In this study, waste heat was evaluated and examined by means of thermophotovoltaic systems with the application of energy production potential GaSb cells. The aim of our study is to examine GaSb cell technology at high temperature waste heat. The evaluation of the waste heat to be used in the system is designed to be used in the electricity, industry and iron and steel industry. Our work is research. Graphic analysis is done with Matlab program. The high temperature waste heat graphs applied on the GaSb cell are in the results section. Our study aims to provide a source for future studies.

Large silver-cadmium technology program

NASA Technical Reports Server (NTRS)

Charlip, S.; Lerner, S.

1971-01-01

The effects of varying cell design on operation factors on the electrochemical performance of sealed, silver-cadmium cells were determined. A factorial experiment was conducted for all test cells constructed with organic separators. Three operating factors were evaluated: temperature, depth of discharge, and charge rate. The six construction factors considered were separator, absorber, electrolyte quantity, cadmium electrode type, cadmium-to-silver ratio, and auxiliary electrode. Test cells of 4 ampere-hour capacity were fabricated and cycled. The best performing cells, on a 94 minute orbit, at 40% depth of discharge, were those containing silver-treated fibrous sausage casings as the separator, and Teflon-ated, pressed cadmium electrodes. Cycling data of cells with inorganic separators (Astroset) are given. Best performance was shown by cells with nonwoven nylon absorbers. Rigid inorganic separators provided the best barrier to silver migration.

CYANOBACTERIA PASSAGE THROUGH DRINKING WATER FILTERS DURING PERTURBATION EPISODES AS A FUNCTION OF CELL MORPHOLOGY, COAGULANT AND INITIAL FILTER LOADING RATE

EPA Science Inventory

Eight pilot-scale in-line filtration trials were performed to evaluate the passage of cyanobacterial cells through drinking water filters after sudden increases in hydraulic loading rates. Trials were performed at 30 degrees C using two coagulant combinations (aluminum sulfate a...

Quantitative evaluation method for differentiation of C2C12 myoblasts by ultrasonic microscopy

NASA Astrophysics Data System (ADS)

Takanashi, Kyoichi; Washiya, Mamoru; Ota, Kazuki; Yoshida, Sachiko; Hozumi, Naohiro; Kobayashi, Kazuto

2017-07-01

Cell differentiation was evaluated by ultrasonic microscopy. However, there were some regions that showed a lower acoustic impedance than the culture liquid. It was considered that, in such regions, the cells were not perfectly in contact with the film substrate. Hence, a waveform analysis was performed, and compensated acoustic impedances in such regions were in a reasonable range of values. By the same analysis, the displacements of partially floated cells were also successfully calculated. The elapsed day transitions of the compensated acoustic impedances and displacements were successfully evaluated. In the process of differentiation, actin fibers comprising the cytoskeleton are supposed to loosen in order to induce cellular fusion. In addition, the progress in cell differentiation accompanied by a change into a three-dimensional structure can partially be assessed by the displacement between a cell and a cultured film. Hence, we believe that cell differentiation can be evaluated using an ultrasonic microscope.

Results of advanced battery technology evaluations for electric vehicle applications

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

1992-10-01

Advanced battery technology evaluations are performed under simulated electric-vehicle operating conditions at the Analysis and Diagnostic Laboratory (ADL) of Argonne National Laboratory. The ADL results provide insight into those factors that limit battery performance and life. The ADL facilities include a test laboratory to conduct battery experimental evaluations under simulated application conditions and a post-test analysis laboratory to determine, in a protected atmosphere if needed, component compositional changes and failure mechanisms. This paper summarizes the performance characterizations and life evaluations conducted during 1991-1992 on both single cells and multi-cell modules that encompass eight battery technologies (Na/S, Li/MS (M=metal), Ni/MH, Ni/Cd, Ni/Zn, Ni/Fe, Zn/Br, and Pb-acid). These evaluations were performed for the Department of Energy, Office of Transportation Technologies, Electric and Hybrid Propulsion Division, and the Electric Power Research Institute. The ADL provides a common basis for battery performance characterization and life evaluations with unbiased application of tests and analyses. The results help identify the most-promising R&D approaches for overcoming battery limitations, and provide battery users, developers, and program managers with a measure of the progress being made in battery R&D programs, a comparison of battery technologies, and basic data for modeling.

Reliable B Cell Epitope Predictions: Impacts of Method Development and Improved Benchmarking

PubMed Central

Kringelum, Jens Vindahl; Lundegaard, Claus; Lund, Ole; Nielsen, Morten

2012-01-01

The interaction between antibodies and antigens is one of the most important immune system mechanisms for clearing infectious organisms from the host. Antibodies bind to antigens at sites referred to as B-cell epitopes. Identification of the exact location of B-cell epitopes is essential in several biomedical applications such as; rational vaccine design, development of disease diagnostics and immunotherapeutics. However, experimental mapping of epitopes is resource intensive making in silico methods an appealing complementary approach. To date, the reported performance of methods for in silico mapping of B-cell epitopes has been moderate. Several issues regarding the evaluation data sets may however have led to the performance values being underestimated: Rarely, all potential epitopes have been mapped on an antigen, and antibodies are generally raised against the antigen in a given biological context not against the antigen monomer. Improper dealing with these aspects leads to many artificial false positive predictions and hence to incorrect low performance values. To demonstrate the impact of proper benchmark definitions, we here present an updated version of the DiscoTope method incorporating a novel spatial neighborhood definition and half-sphere exposure as surface measure. Compared to other state-of-the-art prediction methods, Discotope-2.0 displayed improved performance both in cross-validation and in independent evaluations. Using DiscoTope-2.0, we assessed the impact on performance when using proper benchmark definitions. For 13 proteins in the training data set where sufficient biological information was available to make a proper benchmark redefinition, the average AUC performance was improved from 0.791 to 0.824. Similarly, the average AUC performance on an independent evaluation data set improved from 0.712 to 0.727. Our results thus demonstrate that given proper benchmark definitions, B-cell epitope prediction methods achieve highly significant predictive performances suggesting these tools to be a powerful asset in rational epitope discovery. The updated version of DiscoTope is available at www.cbs.dtu.dk/services/DiscoTope-2.0. PMID:23300419

A Critical Evaluation of the Influence of the Dark Exchange Current on the Performance of Dye-Sensitized Solar Cells

PubMed Central

García-Rodríguez, Rodrigo; Villanueva-Cab, Julio; Anta, Juan A.; Oskam, Gerko

2016-01-01

The influence of the thickness of the nanostructured, mesoporous TiO2 film on several parameters determining the performance of a dye-sensitized solar cell is investigated both experimentally and theoretically. We pay special attention to the effect of the exchange current density in the dark, and we compare the values obtained by steady state measurements with values extracted from small perturbation techniques. We also evaluate the influence of exchange current density, the solar cell ideality factor, and the effective absorption coefficient of the cell on the optimal film thickness. The results show that the exchange current density in the dark is proportional to the TiO2 film thickness, however, the effective absorption coefficient is the parameter that ultimately defines the ideal thickness. We illustrate the importance of the exchange current density in the dark on the determination of the current–voltage characteristics and we show how an important improvement of the cell performance can be achieved by decreasing values of the total series resistance and the exchange current density in the dark. PMID:28787833

Low-Earth-Orbit (LEO) Life Cycle Evaluation of Nickel-Zinc Batteries

NASA Technical Reports Server (NTRS)

Coates, D.; Ferreira, E.; Nyce, M.; Charkey, A.

1997-01-01

The conclusion of the Low-Earth-Orbit (LEO) life cycle evaluation of nickel-zinc batteries are: that composite nickel electrode provide excellent performance at a reduced weight and lower cost; calcium / zinc electrode minimizes shape change; unioptimized cell designs yield 60 Wh/kg; nickel-zinc delivers 600 cycles at 80% DOD; long cycle life obtainable at low DOD; high rate capability power density; long-term failure mechanism is stack dry; and anomalous overcharge (1120%) greatly affected cell performance but did not induce failure and was recoverable.

VERIFICATION OF THE HYDROLOGIC EVALUATION OF LANDFILL PERFORMANCE (HELP) MODEL USING FIELD DATA

EPA Science Inventory

The report describes a study conducted to verify the Hydrologic Evaluation of Landfill Performance (HELP) computer model using existing field data from a total of 20 landfill cells at 7 sites in the United States. Simulations using the HELP model were run to compare the predicted...

Comparative performances of microbial capacitive deionization cell and microbial fuel cell fed with produced water from the Bakken shale.

PubMed

Shrestha, Namita; Chilkoor, Govinda; Wilder, Joseph; Ren, Zhiyong Jason; Gadhamshetty, Venkataramana

2018-06-01

This study evaluates and compares the performance of microbial fuel cells (MFCs) and microbial capacitive deionization cells (MCDCs) fed with wastewater produced from the Bakken shale. The produced water was characterized by high levels of dissolved solids and chemical oxygen demand (COD). Two-compartment MFCs and three-compartment MCDCs were evaluated under batch-fed mode using mixed microbial consortia in the anode, ferricyanide in the cathode, and produced water as the electrolyte in the anode and capacitive deionization units. COD removal in the MFCs was 88%, while that in the MCDCs was limited to 76%. The lower performance of the MCDCs was due to the large impedance (6600 Ω cm 2 ) compared with the MFCs (870 Ω cm 2 ). However, the MCDCs achieved two-fold higher removal of dissolved solids. Both the MFCs and MCDCs suffered from a higher impedance induced by fouling in the latter stages of the operation. Copyright © 2018 Elsevier B.V. All rights reserved.

Performance Characteristics of Lithium Ion Prototype Cells for 2003 Mars Sample Return Athena Rover

NASA Technical Reports Server (NTRS)

Ratnakumar, B. V.; Smart, M. C.; Ewell, R.; Surampudi, S.; Marsh, R. A.

2000-01-01

A viewgraph presentation outlines the mission objectives and power subsystem for the Mars Sample Return (MSR) Athena Rover. The NASA-DOD (depth of discharge) Interagency Li Ion program objectives are discussed. Evaluation tests performed at JPL are listed, and test results are shown for the Li-Ion cell initial capacity, charge/discharge capacity, voltage and ratio, specific energy, watt-hour efficiency, and cell voltage at various temperatures.

Peptide-Based Photoelectrochemical Cytosensor Using a Hollow-TiO2/EG/ZnIn2S4 Cosensitized Structure for Ultrasensitive Detection of Early Apoptotic Cells and Drug Evaluation.

PubMed

Wu, Rong; Fan, Gao-Chao; Jiang, Li-Ping; Zhu, Jun-Jie

2018-02-07

The ability to rapidly detect apoptotic cells and accurately evaluate therapeutic effects is significant in cancer research. To address this target, a biocompatible, ultrasensitive photoelectrochemical (PEC) cytosensing platform was developed based on electrochemically reduced graphene (EG)/ZnIn 2 S 4 cosensitized TiO 2 coupled with specific recognition between apoptotic cells and phosphatidylserine-binding peptide (PSBP). In this strategy, the HL-60 cells were selected as a model and C005, nilotinib, and imatinib were selected as apoptosis inducers to show cytosensing performances. In particular, a TiO 2 photoactive substrate was designed as hollow spheres to enhance the PEC performance. Graphene was electrodeposited on the hollow TiO 2 -modified electrode to accelerate electron transfer and increase conductivity, followed by in situ growth of ZnIn 2 S 4 nanocrystals as photosensitizers via successive ionic layer adsorption and reaction method, forming a TiO 2 /EG/ZnIn 2 S 4 cosensitized structure that was used as a PEC matrix to immobilize PSBP for the recognition of early apoptotic cells. The detection of apoptotic cells was based on steric hindrance originating from apoptotic cell capture to induce an obvious decrease in the photocurrent signal. The ultrahigh sensitivity of the cytosensor resulted from enhanced PEC performance, bioactivity, and high binding affinity between PSBP and apoptotic cells. Compared with other assays, incorporate toxic elements were avoided, such as Cd, Ru, and Te, which ensured normal cell growth and are appropriate for cell analysis. The designed PEC cytosensor showed a low detection limit of apoptotic cells (as low as three cells), a wide linear range from 1 × 10 3 to 5 × 10 7 cells/mL, and an accurate evaluation of therapeutic effects. It also exhibited good specificity, reproducibility, and stability.

Properties and Performance Attributes of Novel Co-extruded Polyolefin Battery Separator Materials. Part 2; Electrical Properties

NASA Technical Reports Server (NTRS)

Baldwin, Richard S.

2013-01-01

As NASA prepares for its next era of manned spaceflight missions, advanced energy storage technologies are being developed and evaluated to address and enhance future mission needs and technical requirements. Cell-level components for advanced lithium-ion batteries possessing higher energy, more reliable performance and enhanced, inherent safety characteristics have been under development within the NASA infrastructure. A key component for safe and reliable cell performance is the cell separator, which separates the two energetic electrodes and functions to inhibit the occurrence of an internal short circuit but preserves an ionic current. Recently, a new generation of co-extruded separator films has been developed by ExxonMobil Chemical and introduced into their battery separator product portfolio. Several grades of this new separator material were evaluated with respect to dynamic mechanical properties and safety-related performance attributes, and the results of these evaluations were previously reported in "Part 1: Mechanical Properties" of this publication. This current paper presents safety-related performance results for these novel materials obtained by employing a complementary experimental methodology, which involved the analysis of separator impedance characteristics as a function of temperature. The experimental results from this study are discussed with respect to potential cell safety enhancement for future aerospace as well as for terrestrial energy storage needs, and they are compared with pertinent mechanical properties of these materials, as well as with current state-of-the practice separator materials.

A Comparison of Two Panasonic Lithium-Ion Batteries and Cells for the IBM Thinkpad

NASA Technical Reports Server (NTRS)

Jeevarajan, Judith A.; Cook, Joseph S.; Davies, Francis J.; Collins, Jacob; Bragg, Bobby J.

2003-01-01

The IBM Thinkpad 760XD has been used in the Orbiter and International Space Station since 2000. The Thinkpad is powered by a Panasonic Li-ion battery that has a voltage of 10.8 V and 3.0 Ah capacity. This Thinkpad is now being replaced by the IBM Thinkpad A31P which has a Panasonic Li-ion battery that has a voltage of 10.8 V and 4.0 Ah capacity. Both batteries have protective circuit boards. The Panasonic battery for the Thinkpad 760XD had 12 Panasonic 17500 cells of 0.75 Ah capacity in a 4P3S cOnfiguration. The new Panasonic battery has 6 Panasonic 18650 cells of 2.0 Ah capacity in a 2P3S configuration. The batteries and cells for both models have been evaluated for performance and safety. A comparison of the cells under similar test conditions will be presented. The performance of the cells has been evaluated under different rates of charge and discharge and different temperatures. The cells have been tested under abuse conditions and the safety features in the cells evaluated. The protective circuit board in the battery was also tested under conditions of overcharge, overdischarge, short circuit and unbalanced cell configurations. The results of the studies will be presented in this paper.

Solid Polymer Electrolyte Fuel Cell Technology Program

NASA Technical Reports Server (NTRS)

1980-01-01

Work is reported on phase 5 of the Solid Polymer Electrolyte (SPE) Fuel Cell Technology Development program. The SPE fuel cell life and performance was established at temperatures, pressures, and current densities significantly higher than those previously demonstrated in sub-scale hardware. Operation of single-cell Buildup No. 1 to establish life capabilities of the full-scale hardware was continued. A multi-cell full-scale unit (Buildup No. 2) was designed, fabricated, and test evaluated laying the groundwork for the construction of a reactor stack. A reactor stack was then designed, fabricated, and successfully test-evaluated to demonstrate the readiness of SPE fuel cell technology for future space applications.

Evaluation of musculoskeletal sepsis with indium-111 white blood cell imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouzounian, T.J.; Thompson, L.; Grogan, T.J.

The detection of musculoskeletal sepsis, especially following joint replacement, continues to be a challenging problem. Often, even with invasive diagnostic evaluation, the diagnosis of infection remains uncertain. This is a report on the first 55 Indium-111 white blood cell (WBC) images performed in 39 patients for the evaluation of musculoskeletal sepsis. There were 40 negative and 15 positive Indium-111 WBC images. These were correlated with operative culture and tissue pathology, aspiration culture, and clinical findings. Thirty-eight images were performed for the evaluation of possible total joint sepsis (8 positive and 30 negative images); 17 for the evaluation of nonarthroplasty-related musculoskeletalmore » sepsis (7 positive and 10 negative images). Overall, there were 13 true-positive, 39 true-negative, two false-positive, and one false-negative images. Indium-111 WBC imaging is a sensitive and specific means of evaluating musculoskeletal sepsis, especially following total joint replacement.« less

Fabrication, Characterization, and Evaluation of Bionanocomposites Based on Natural Polymers and Antibiotics for Wound Healing Applications.

PubMed

Rădulescu, Marius; Holban, Alina Maria; Mogoantă, Laurențiu; Bălşeanu, Tudor-Adrian; Mogoșanu, George Dan; Savu, Diana; Popescu, Roxana Cristina; Fufă, Oana; Grumezescu, Alexandru Mihai; Bezirtzoglou, Eugenia; Lazar, Veronica; Chifiriuc, Mariana Carmen

2016-06-10

The aim of our research activity was to obtain a biocompatible nanostructured composite based on naturally derived biopolymers (chitin and sodium alginate) loaded with commercial antibiotics (either Cefuroxime or Cefepime) with dual functions, namely promoting wound healing and assuring the local delivery of the loaded antibiotic. Compositional, structural, and morphological evaluations were performed by using the thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and fourier transform infrared spectroscopy (FTIR) analytical techniques. In order to quantitatively and qualitatively evaluate the biocompatibility of the obtained composites, we performed the tetrazolium-salt (MTT) and agar diffusion in vitro assays on the L929 cell line. The evaluation of antimicrobial potential was evaluated by the viable cell count assay on strains belonging to two clinically relevant bacterial species (i.e., Escherichia coli and Staphylococcus aureus).

RECENT ADVANCES IN HIGH TEMPERATURE ELECTROLYSIS AT IDAHO NATIONAL LABORATORY: SINGLE CELL TESTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

X. Zhang; J. E. O'Brien; R. C. O'Brien

2012-07-01

An experimental investigation on the performance and durability of single solid oxide electrolysis cells (SOECs) is under way at the Idaho National Laboratory. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOECs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. A new test apparatus has been developed for single cell and small stack tests from different vendors. Single cells from Ceramatec Inc. show improved durability compared to our previous stack tests. Single cells from Materials and Systems Research Inc. (MSRI) demonstrate low degradation both in fuel cellmore » and electrolysis modes. Single cells from Saint Gobain Advanced Materials (St. Gobain) show stable performance in fuel cell mode, but rapid degradation in the electrolysis mode. Electrolyte-electrode delamination is found to have significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the microstructure help to mitigate degradation. Polarization scans and AC impedance measurements are performed during the tests to characterize the cell performance and degradation.« less

Evaluation of engraftment of superparamagnetic iron oxide-labeled mesenchymal stem cells using three-dimensional reconstruction of magnetic resonance imaging in photothrombotic cerebral infarction models of rats.

PubMed

Shim, Jaehyun; Kwak, Byung Kook; Jung, Jisung; Park, Serah

2015-01-01

To evaluate engraftment by visualizing the location of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) three-dimensionally in photothrombotic cerebral infarction (PTCI) models of rats. Magnetic resonance imaging (MRI) of an agarose block containing superparamagnetic iron oxide (SPIO)-labeled hBM-MSCs was performed using a 3.0-T MRI, T2-(T2WI), T2(*)-(T2(*)WI), and susceptibility-weighted images (SWI). PTCI was induced in 6 rats, and 2.5 × 10(5) SPIO-labeled hBM-MSCs were infused through the ipsilateral internal carotid artery (ICA group) or tail vein (IV group). MRI was performed on days 1, 3, 7, and 14 after stem cell injection. Dark signal regions were confirmed using histology. Three-dimensional MRI reconstruction was performed using the clinical workflow solution to evaluate the engraftment of hBM-MSCs. Volumetric analysis of the engraftment was also performed. The volumes of SPIO-labeled hBM-MSCs in the phantom MRI were 129.3, 68.4, and 25.9 µL using SWI, T2(*)WI, and T2WI, respectively. SPIO-labeled hBM-MSCs appeared on day 1 after injection, encircling the cerebral infarction from the ventral side. Dark signal regions matched iron positive cells and human origin (positive) cells. The volume of the engraftment was larger in the ICA group on days 1, 3, and 7, after stem cell injection (p < 0.05 on SWI). SWI was the most sensitive MRI pulse sequence (p < 0.05). The volume of infarction decreased until day 14. The engraftment of SPIO-labeled hBM-MSCs can be visualized and evaluated three-dimensionally in PTCI models of rats. The engraftment volume was larger in the ICA group than IV group on early stage within one week.

Afzelin exhibits anti-cancer activity against androgen-sensitive LNCaP and androgen-independent PC-3 prostate cancer cells through the inhibition of LIM domain kinase 1.

PubMed

Zhu, Kai-Chang; Sun, Jian-Mei; Shen, Jian-Guo; Jin, Ji-Zhong; Liu, Feng; Xu, Xiao-Lin; Chen, Lin; Liu, Lin-Tao; Lv, Jia-Ju

2015-10-01

Prostate cancer presents high occurrence worldwide. Medicinal plants are a major source of novel and potentially therapeutic molecules; therefore, the aim of the present study was to investigate the possible anti-prostate cancer activity of afzelin, a flavonol glycoside that was previously isolated from Nymphaea odorata . The effect of afzelin on the proliferation of androgen-sensitive LNCaP and androgen-independent PC-3 cells was evaluated by performing a water soluble tetrazolium salt-1 assay. In addition, the effect of afzelin on the cell cycle of the LNCaP and PC-3 prostate cancer cell lines was evaluated. Western blot analysis was performed to evaluate the effect of afzelin on the kinases responsible for the regulation of actin organization. Afzelin was identified to inhibit the proliferation of LNCaP and PC3 cells, and block the cell cycle in the G 0 phase. The anticancer activity of afzelin in these cells was determined to be due to inhibition of LIM domain kinase 1 expression. Thus, the in vitro efficacy of afzelin against prostate cancer is promising; however, additional studies on different animal models are required to substantiate its anticancer potential.

Afzelin exhibits anti-cancer activity against androgen-sensitive LNCaP and androgen-independent PC-3 prostate cancer cells through the inhibition of LIM domain kinase 1

PubMed Central

ZHU, KAI-CHANG; SUN, JIAN-MEI; SHEN, JIAN-GUO; JIN, JI-ZHONG; LIU, FENG; XU, XIAO-LIN; CHEN, LIN; LIU, LIN-TAO; LV, JIA-JU

2015-01-01

Prostate cancer presents high occurrence worldwide. Medicinal plants are a major source of novel and potentially therapeutic molecules; therefore, the aim of the present study was to investigate the possible anti-prostate cancer activity of afzelin, a flavonol glycoside that was previously isolated from Nymphaea odorata. The effect of afzelin on the proliferation of androgen-sensitive LNCaP and androgen-independent PC-3 cells was evaluated by performing a water soluble tetrazolium salt-1 assay. In addition, the effect of afzelin on the cell cycle of the LNCaP and PC-3 prostate cancer cell lines was evaluated. Western blot analysis was performed to evaluate the effect of afzelin on the kinases responsible for the regulation of actin organization. Afzelin was identified to inhibit the proliferation of LNCaP and PC3 cells, and block the cell cycle in the G0 phase. The anticancer activity of afzelin in these cells was determined to be due to inhibition of LIM domain kinase 1 expression. Thus, the in vitro efficacy of afzelin against prostate cancer is promising; however, additional studies on different animal models are required to substantiate its anticancer potential. PMID:26622852

Performance evaluation of the Abbott CELL-DYN Ruby and the Sysmex XT-2000i haematology analysers.

PubMed

Leers, M P G; Goertz, H; Feller, A; Hoffmann, J J M L

2011-02-01

Two mid-range haematology analysers (Abbott CELL-DYN Ruby and Sysmex XT-2000i) were evaluated to determine their analytical performance and workflow efficiency in the haematology laboratory. In total 418 samples were processed for determining equivalence of complete blood count (CBC) measurements, and 100 for reticulocyte comparison. Blood smears served for assessing the agreement of the differential counts. Inter-instrument agreement for most parameters was good although small numbers of discrepancies were observed. Systematic biases were found for mean cell volume, reticulocytes, platelets and mean platelet volume. CELL-DYN Ruby WBC differentials were obtained with all samples while the XT-2000i suppressed differentials partially or completely in 13 samples (3.1%). WBC subpopulation counts were otherwise in good agreement with no major outliers. Following first-pass CBC/differential analysis, 88 (21%) of XT-2000i samples required further analyser processing compared to 18 (4.3%) for the CELL-DYN Ruby. Smear referrals for suspected WBC/nucleated red blood cells and platelet abnormalities were indicated for 106 (25.4%) and 95 (22.7%) of the XT-2000i and CELL-DYN Ruby samples respectively. Flagging efficiencies for both analysers were found to be similar. The Sysmex XT-2000i and Abbott CELL-DYN Ruby analysers have broadly comparable analytical performance, but the CELL-DYN Ruby showed superior first-pass efficiency. © 2010 Blackwell Publishing Ltd.

Evaluation parameters for the alkaline fuel cell oxygen electrode

NASA Technical Reports Server (NTRS)

Singer, J.; Srinivasan, V.

1985-01-01

Studies were made of Pt- and Au-catalyzed porous electrodes, designed for the cathode of the alkaline H2/O2 fuel cell, employing cyclic voltammetry and the floating half-cell method. The purpose was to obtain parameters from the cyclic voltammograms which could predict performance in the fuel cell. It was found that a satisfactory relationship between these two types of measurement could not be established; however, useful observations were made of relative performance of several types of carbon used as supports for noble metal catalysts and of some Au catalysts. The best half-cell performance with H2/O2 in a 35 percent KOH electrolyte at 80 C was given by unsupported fine particle Au on Teflon; this electrode is used in the Orbiter fuel cell.

Characterization of three types of silicon solar cells for SEPS deep-space missions. Volume 2: Current voltage characteristics of Solarex textured P(+)8 to 10 mil, planar P(+)8 to 10 mil and planar P(+)2 mil cells as a function of temperature and intensity

NASA Technical Reports Server (NTRS)

Whitaker, A. F.; Little, S. A.; Wooden, V. A.

1980-01-01

Three types of high performance silicon solar cells, textured P(+)8 to 10 mil, planar P(+)8 to 10 mil and planar P(+)2 mil were evaluated for their low temperature and low intensity (LTLI) performance. Sixteen cells of each type were subjected to 11 temperatures and 9 intensities. The textured P(+)8 to 10 mil cells provided the best performance both at 1 astronomical unit and at LTLI conditions. The average efficiencies of this cell were 14.5 percent at 1 solar constant/+25 C and 18.7 percent at 0.086 solar constant/-100 C.

Microfluidics for Cancer Nanomedicine: From Fabrication to Evaluation.

PubMed

Zhang, Hao; Zhu, Yifeng; Shen, Youqing

2018-05-27

Self-assembled drug delivery systems (sDDSs), made from nanocarriers and drugs, are one of the major types of nanomedicines, many of which are in clinical use, under preclinical investigation, or in clinical trials. One of the hurdles of this type of nanomedicine in real applications is the inherent complexity of their fabrication processes, which generally lack precise control over the sDDS structures and the batch-to-batch reproducibility. Furthermore, the classic 2D in vitro cell model, monolayer cell culture, has been used to evaluate sDDSs. However, 2D cell culture cannot adequately replicate in vivo tissue-level structures and their highly complex dynamic 3D environments, nor can it simulate their functions. Thus, evaluations using 2D cell culture often cannot correctly correlate with sDDS behaviors and effects in humans. Microfluidic technology offers novel solutions to overcome these problems and facilitates studying the structure-performance relationships for sDDS developments. In this Review, recent advances in microfluidics for 1) fabrication of sDDSs with well-defined physicochemical properties, such as size, shape, rigidity, and drug-loading efficiency, and 2) fabrication of 3D-cell cultures as "tissue/organ-on-a-chip" platforms for evaluations of sDDS biological performance are in focus. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Develop and test fuel cell powered on-site integrated total energy systems

NASA Technical Reports Server (NTRS)

Kaufman, A.; Pudick, S.; Wang, C. L.; Werth, J.; Whelan, J. A.

1984-01-01

On-going testing of an 11 cell, 10.7 in. x 14 in. stack (about 1 kW) reached 2600 hours on steady load. Nonmetallic cooling plates and an automated electrolyte replenishment system continued to perform well. A 10 cell, 10.7 in. x 14 in. stack was constructed with a modified electrolyte matrix configuration for the purpose of reducing cell IR loss. The desired effect was achieved, but the general cell performance level was irregular. Evaluation is continuing. Preparations for a long term 25 cell, 13 in. x 23 in. test stack (about 4 kW) approached completion. Start up in early May 1984 is expected.

Synthesis and biological evaluation of nandrolone-bodipy conjugates.

PubMed

Jurášek, Michal; Rimpelová, Silvie; Pavlíčková, Vladimíra; Ruml, Tomáš; Lapčík, Oldřich; Drašar, Pavel B

2015-05-01

Here, we report synthesis and biological evaluation of fluorescent nandrolone-3-carboxymethyloxime derivatives conjugated with green-emitting bodipy dye via PEG linkers. All the newly-synthesized compounds were evaluated for their effect on cell proliferation in vitro in MCF-7, LNCaP, PC-3 and HEK 293T model cell lines using WST-1 assay. By means of live-cell fluorescence microscopy, the intracellular localization of nandrolone-bodipy conjugates was revealed in endoplasmic reticulum. Moreover, we performed competitive localization study with nonfluorescent nandrolone, metandrolone, boldenone, trenbolone, and testosterone. Copyright © 2014 Elsevier Inc. All rights reserved.

Performance of 12Ah aerospace nickel-cadmium cells of design variable groups

NASA Astrophysics Data System (ADS)

Vasanth, K. L.

1985-12-01

The design variable program of NASA is a systematic approach to evaluate the performance of 12Ah aerospace nickel-cadmium cells of 9 important cell designs. These cells were life cycled in a Low-Earth Orbit (LEO) regime for 3 to 4 years. Representative cells taken from the design variable groups after different cycling periods have been examined. The results show that: (1) positive swelling and carbonate content in the electrolyte increases as a function of the number of cycles, (2) electrolyte distribution follows the order NEG greater than POS greater than SEP, 3) control and no PQ groups outperformed the rest of the groups and (4) the polypropylene group shows very heavy cadmium migration and poor performance.

Performance of 12Ah aerospace nickel-cadmium cells of design variable groups

NASA Technical Reports Server (NTRS)

Vasanth, K. L.

1985-01-01

The design variable program of NASA is a systematic approach to evaluate the performance of 12Ah aerospace nickel-cadmium cells of 9 important cell designs. These cells were life cycled in a Low-Earth Orbit (LEO) regime for 3 to 4 years. Representative cells taken from the design variable groups after different cycling periods have been examined. The results show that: (1) positive swelling and carbonate content in the electrolyte increases as a function of the number of cycles, (2) electrolyte distribution follows the order NEG greater than POS greater than SEP, 3) control and no PQ groups outperformed the rest of the groups and (4) the polypropylene group shows very heavy cadmium migration and poor performance.

Performance of high intensity fed-batch mammalian cell cultures in disposable bioreactor systems.

PubMed

Smelko, John Paul; Wiltberger, Kelly Rae; Hickman, Eric Francis; Morris, Beverly Janey; Blackburn, Tobias James; Ryll, Thomas

2011-01-01

The adoption of disposable bioreactor technology as an alternate to traditional nondisposable technology is gaining momentum in the biotechnology industry. Evaluation of current disposable bioreactors systems to sustain high intensity fed-batch mammalian cell culture processes needs to be explored. In this study, an assessment was performed comparing single-use bioreactors (SUBs) systems of 50-, 250-, and 1,000-L operating scales with traditional stainless steel (SS) and glass vessels using four distinct mammalian cell culture processes. This comparison focuses on expansion and production stage performance. The SUB performance was evaluated based on three main areas: operability, process scalability, and process performance. The process performance and operability aspects were assessed over time and product quality performance was compared at the day of harvest. Expansion stage results showed disposable bioreactors mirror traditional bioreactors in terms of cellular growth and metabolism. Set-up and disposal times were dramatically reduced using the SUB systems when compared with traditional systems. Production stage runs for both Chinese hamster ovary and NS0 cell lines in the SUB system were able to model SS bioreactors runs at 100-, 200-, 2,000-, and 15,000-L scales. A single 1,000-L SUB run applying a high intensity fed-batch process was able to generate 7.5 kg of antibody with comparable product quality. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

Integrated economic and experimental framework for screening of primary recovery technologies for high cell density CHO cultures

PubMed Central

Popova, Daria; Stonier, Adam; Pain, David; Titchener‐Hooker, Nigel J.

2016-01-01

Abstract Increases in mammalian cell culture titres and densities have placed significant demands on primary recovery operation performance. This article presents a methodology which aims to screen rapidly and evaluate primary recovery technologies for their scope for technically feasible and cost‐effective operation in the context of high cell density mammalian cell cultures. It was applied to assess the performance of current (centrifugation and depth filtration options) and alternative (tangential flow filtration (TFF)) primary recovery strategies. Cell culture test materials (CCTM) were generated to simulate the most demanding cell culture conditions selected as a screening challenge for the technologies. The performance of these technology options was assessed using lab scale and ultra scale‐down (USD) mimics requiring 25–110mL volumes for centrifugation and depth filtration and TFF screening experiments respectively. A centrifugation and depth filtration combination as well as both of the alternative technologies met the performance selection criteria. A detailed process economics evaluation was carried out at three scales of manufacturing (2,000L, 10,000L, 20,000L), where alternative primary recovery options were shown to potentially provide a more cost‐effective primary recovery process in the future. This assessment process and the study results can aid technology selection to identify the most effective option for a specific scenario. PMID:27067803

The evaluation of a new apheresis device for automated red blood cell exchange procedures in patients with sickle cell disease.

PubMed

Quirolo, Keith; Bertolone, Salvatore; Hassell, Kathryn; Howard, Thomas; King, Karen E; Rhodes, Diane K; Bill, Jerry

2015-04-01

The Spectra Optia apheresis system (SO), a blood component separator, can be used to perform red blood cell exchange (RBCX) procedures for the transfusion management of sickle cell disease (SCD) in adults and children. This study was designed to evaluate the performance of the SO RBCX protocols (exchange and depletion/exchange) in patients with SCD. Patients with SCD and a need for an RBCX procedure as part of a chronic program or as a single procedure were enrolled in this multicenter, single-arm, open-label study. The primary goal of the study was to confirm that the predicted percentage of the patient's original RBCs remaining at the end of the procedure (FCRp) reflects the actual cell fraction remaining, as measured by %HbS (FCRa). Secondary endpoints included ability of the SO to achieve the desired final hematocrit (Hct) and device-related serious adverse events (SAEs). Seventy-two patients 12 years of age or older were enrolled in the study; 60 were evaluable. The ratio of FCRa to FCRp after the RBCX procedure was 0.90, well within the prespecified range of 0.75 to 1.25. The SO was able to achieve the desired final Hct in the evaluable population. The safety profile was favorable, and no patients had an SAE or unexpected adverse device effect or withdrew from the procedure or treatment due to an adverse event. The SO performed effectively and safely for both the RBCX procedure and the RBCX depletion/exchange procedure. © 2014 AABB.

In vitro investigation of anodization and CaP deposited titanium surface using MG63 osteoblast-like cells

NASA Astrophysics Data System (ADS)

Lee, J. M.; Lee, J. I.; Lim, Y. J.

2010-03-01

The aim of the present study was to investigate surface characteristics in four different titanium surfaces (AN: anodized at 270 V; AN-CaP: anodic oxidation and CaP deposited; SLA: sandblasted and acid etched; MA: machined) and to evaluate biological behaviors such as cell adhesion, cell proliferation, cytoskeletal organization, and osteogenic protein expression of MG63 osteoblast-like cells at the early stage. Surface analysis was performed using scanning electron microscopy, thin-film X-ray diffractometry, and a confocal laser scanning microscope. In order to evaluate cellular responses, MG63 osteoblast-like cells were used. The cell viability was evaluated by MTT assay. Immunofluorescent analyses of actin, type I collagen, osteonectin and osteocalcin were performed. The anodized and CaP deposited specimen showed homogeneously distributed CaP particles around micropores and exhibited anatase type oxides, titanium, and HA crystalline structures. This experiment suggests that CaP particles on the anodic oxidation surface affect cellular attachment and spreading. When designing an in vitro biological study for CaP coated titanium, it must be taken into account that preincubation in medium prior to cell seeding and the cell culture medium may affect the CaP coatings. All these observations illustrate the importance of the experimental conditions and the physicochemical parameters of the CaP coating. It is considered that further evaluations such as long-term in vitro cellular assays and in vivo experiments should be necessary to figure out the effect of CaP deposition to biological responses.

Improving Primary Care Residents' Proficiency in the Diagnosis of Skin Cancer

PubMed Central

Gerbert, Barbara; Bronstone, Amy; Wolff, Mimi; Maurer, Toby; Berger, Timothy; Pantilat, Steven; McPhee, Stephen J

1998-01-01

OBJECTIVE To determine whether a brief, multicomponent intervention could improve the skin cancer diagnosis and evaluation planning performance of primary care residents to a level equivalent to that of dermatologists. PARTICIPANTS Fifty-two primary care residents (26 in the control group and 26 in the intervention group) and 13 dermatologists completed a pretest and posttest. DESIGN A randomized, controlled trial with pretest and posttest measurements of residents' ability to diagnose and make evaluation plans for lesions indicative of skin cancer. INTERVENTION The intervention included face-to-face feedback sessions focusing on residents' performance deficiencies; an interactive seminar including slide presentations, case examples, and live demonstrations; and the Melanoma Prevention Kit including a booklet, magnifying tool, measuring tool, and skin color guide. MEASUREMENTS AND MAIN RESULTS We compared the abilities of a control and an intervention group of primary care residents, and a group of dermatologists to diagnose and make evaluation plans for six categories of skin lesions including three types of skin cancer—malignant melanoma, squamous cell carcinoma, and basal cell carcinoma. At posttest, both the intervention and control group demonstrated improved performance, with the intervention group revealing significantly larger gains. The intervention group showed greater improvement than the control group across all six diagnostic categories (a gain of 13 percentage points vs 5, p < .05), and in evaluation planning for malignant melanoma (a gain of 46 percentage points vs 36, p < .05) and squamous cell carcinoma (a gain of 42 percentage points vs 21, p < .01). The intervention group performed as well as the dermatologists on five of the six skin cancer diagnosis and evaluation planning scores with the exception of the diagnosis of basal cell carcinoma. CONCLUSIONS Primary care residents can diagnose and make evaluation plans for cancerous skin lesions, including malignant melanoma, at a level equivalent to that of dermatologists if they receive relevant, targeted education. PMID:9502368

Nickel hydrogen battery cell storage matrix test

NASA Technical Reports Server (NTRS)

Wheeler, James R.; Dodson, Gary W.

1993-01-01

Test were conducted to evaluate post storage performance of nickel hydrogen cells with various design variables, the most significant being nickel precharge versus hydrogen precharge. Test procedures and results are presented in outline and graphic form.

Expression of HES and HEY genes in infantile hemangiomas.

PubMed

Adepoju, Omotinuwe; Wong, Alvin; Kitajewski, Alex; Tong, Karen; Boscolo, Elisa; Bischoff, Joyce; Kitajewski, Jan; Wu, June K

2011-08-11

Infantile hemangiomas (IHs) are the most common benign tumor of infancy, yet their pathogenesis is poorly understood. IHs are believed to originate from a progenitor cell, the hemangioma stem cell (HemSC). Recent studies by our group showed that NOTCH proteins and NOTCH ligands are expressed in hemangiomas, indicating Notch signaling may be active in IHs. We sought to investigate downstream activation of Notch signaling in hemangioma cells by evaluating the expression of the basic HLH family proteins, HES/HEY, in IHs. HemSCs and hemangioma endothelial cells (HemECs) are isolated from freshly resected hemangioma specimens. Quantitative RT-PCR was performed to probe for relative gene transcript levels (normalized to beta-actin). Immunofluorescence was performed to evaluate protein expression. Co-localization studies were performed with CD31 (endothelial cells) and NOTCH3 (peri-vascular, non-endothelial cells). HemSCs were treated with the gamma secretase inhibitor (GSI) Compound E, and gene transcript levels were quantified with real-time PCR. HEY1, HEYL, and HES1 are highly expressed in HemSCs, while HEY2 is highly expressed in HemECs. Protein expression evaluation by immunofluorescence confirms that HEY2 is expressed by HemECs (CD31+ cells), while HEY1, HEYL, and HES1 are more widely expressed and mostly expressed by perivascular cells of hemangiomas. Inhibition of Notch signaling by addition of GSI resulted in down-regulation of HES/HEY genes. HES/HEY genes are expressed in IHs in cell type specific patterns; HEY2 is expressed in HemECs and HEY1, HEYL, HES1 are expressed in HemSCs. This pattern suggests that HEY/HES genes act downstream of Notch receptors that function in distinct cell types of IHs. HES/HEY gene transcripts are decreased with the addition of a gamma-secretase inhibitor, Compound E, demonstrating that Notch signaling is active in infantile hemangioma cells.

Lithium D-cell study

NASA Technical Reports Server (NTRS)

Size, P.; Takeuchi, Esther S.

1993-01-01

The purpose of this contract is to evaluate parametrically the effects of various factors including the electrolyte type, electrolyte concentration, depolarizer type, and cell configuration on lithium cell electrical performance and safety. This effort shall allow for the selection and optimization of cell design for future NASA applications while maintaining close ties with WGL's continuous improvements in manufacturing processes and lithium cell design. Taguchi experimental design techniques are employed in this task, and allow for a maximum amount of information to be obtained while requiring significantly less cells than if a full factorial design were employed. Acceptance testing for this task is modeled after the NASA Document EP5-83-025, Revision C, for cell weights, OCV's and load voltages. The performance attributes that are studied in this effort are fresh capacity and start-up characteristics evaluated at two rates and two temperatures, shelf-life characteristics including start-up and capacity retention, and iterative microcalorimetry measurements. Abuse testing includes forced over discharge at two rates with and without diode protection, temperature tolerance testing, and shorting tests at three rates with the measurement of heat generated during shorting conditions.

Leucocyte classification for leukaemia detection using image processing techniques.

PubMed

Putzu, Lorenzo; Caocci, Giovanni; Di Ruberto, Cecilia

2014-11-01

The counting and classification of blood cells allow for the evaluation and diagnosis of a vast number of diseases. The analysis of white blood cells (WBCs) allows for the detection of acute lymphoblastic leukaemia (ALL), a blood cancer that can be fatal if left untreated. Currently, the morphological analysis of blood cells is performed manually by skilled operators. However, this method has numerous drawbacks, such as slow analysis, non-standard accuracy, and dependences on the operator's skill. Few examples of automated systems that can analyse and classify blood cells have been reported in the literature, and most of these systems are only partially developed. This paper presents a complete and fully automated method for WBC identification and classification using microscopic images. In contrast to other approaches that identify the nuclei first, which are more prominent than other components, the proposed approach isolates the whole leucocyte and then separates the nucleus and cytoplasm. This approach is necessary to analyse each cell component in detail. From each cell component, different features, such as shape, colour and texture, are extracted using a new approach for background pixel removal. This feature set was used to train different classification models in order to determine which one is most suitable for the detection of leukaemia. Using our method, 245 of 267 total leucocytes were properly identified (92% accuracy) from 33 images taken with the same camera and under the same lighting conditions. Performing this evaluation using different classification models allowed us to establish that the support vector machine with a Gaussian radial basis kernel is the most suitable model for the identification of ALL, with an accuracy of 93% and a sensitivity of 98%. Furthermore, we evaluated the goodness of our new feature set, which displayed better performance with each evaluated classification model. The proposed method permits the analysis of blood cells automatically via image processing techniques, and it represents a medical tool to avoid the numerous drawbacks associated with manual observation. This process could also be used for counting, as it provides excellent performance and allows for early diagnostic suspicion, which can then be confirmed by a haematologist through specialised techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

Tilted pillar array fabrication by the combination of proton beam writing and soft lithography for microfluidic cell capture Part 2: Image sequence analysis based evaluation and biological application.

PubMed

Járvás, Gábor; Varga, Tamás; Szigeti, Márton; Hajba, László; Fürjes, Péter; Rajta, István; Guttman, András

2018-02-01

As a continuation of our previously published work, this paper presents a detailed evaluation of a microfabricated cell capture device utilizing a doubly tilted micropillar array. The device was fabricated using a novel hybrid technology based on the combination of proton beam writing and conventional lithography techniques. Tilted pillars offer unique flow characteristics and support enhanced fluidic interaction for improved immunoaffinity based cell capture. The performance of the microdevice was evaluated by an image sequence analysis based in-house developed single-cell tracking system. Individual cell tracking allowed in-depth analysis of the cell-chip surface interaction mechanism from hydrodynamic point of view. Simulation results were validated by using the hybrid device and the optimized surface functionalization procedure. Finally, the cell capture capability of this new generation microdevice was demonstrated by efficiently arresting cells from a HT29 cell-line suspension. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Advanced Fuel Cell System (Phase 4)

NASA Technical Reports Server (NTRS)

Meyer, A. P.; Bell, W. F.

1976-01-01

A multiple-task research and development program was performed to improve the weight, life, and performance characteristics of hydrogen-oxygen alkaline fuel cells for advanced power systems. During Phase 4, the lowest stabilized degradation rate observed in all the testing completed during four phases of the program, 1 microvolt/hour, was demonstrated. This test continues after 5,000 hours of operation. The cell incorporates a PPf anode, a 90Au/10Pt cathode, a hybrid frame, and a Fybex matrix. These elements were developed under this program to extend cell life. The result demonstrated that the 80Au/20Pt cathode is as stable as a 90Au/10Pt cathode of twice the precious metal loading, was confirmed in full-scale cells. A hybrid frame two-cell plaque with dedicated flow fields and manifolds for all fluids was demonstrated to prevent the cell-to cell electrolyte transfer that limited the endurance of multicell plaques. At the conclusion of Phase 4, more than 90,900 hours of testing had been completed and twelve different cell designs had been evaluated. A technology base has been established which is ready for evaluation at the powerplant level.

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

PubMed Central

Oliveira, Rodrigo Juliano; Pesarini, João Renato; Sparça Salles, Maria José; Nakamura Kanno, Tatiane Yumi; dos Santos Lourenço, Ana Carolina; da Silva Leite, Véssia; da Silva, Ariane Fernanda; Matiazi, Hevenilton José; Ribeiro, Lúcia Regina; Mantovani, Mário Sérgio

2014-01-01

β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63–116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20–52.54% and −0.95–62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide. PMID:24688298

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide.

PubMed

Oliveira, Rodrigo Juliano; Pesarini, João Renato; Sparça Salles, Maria José; Nakamura Kanno, Tatiane Yumi; Dos Santos Lourenço, Ana Carolina; da Silva Leite, Véssia; da Silva, Ariane Fernanda; Matiazi, Hevenilton José; Ribeiro, Lúcia Regina; Mantovani, Mário Sérgio

2014-03-01

β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63-116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20-52.54% and -0.95-62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide.

Thermal and optical performance of encapsulation systems for flat-plate photovoltaic modules

NASA Technical Reports Server (NTRS)

Minning, C. P.; Coakley, J. F.; Perrygo, C. M.; Garcia, A., III; Cuddihy, E. F.

1981-01-01

The electrical power output from a photovoltaic module is strongly influenced by the thermal and optical characteristics of the module encapsulation system. Described are the methodology and computer model for performing fast and accurate thermal and optical evaluations of different encapsulation systems. The computer model is used to evaluate cell temperature, solar energy transmittance through the encapsulation system, and electric power output for operation in a terrestrial environment. Extensive results are presented for both superstrate-module and substrate-module design schemes which include different types of silicon cell materials, pottants, and antireflection coatings.

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 40.0 ampere hour nickel cadmium spacecraft cells for the tracking data relay satellite system

NASA Technical Reports Server (NTRS)

Hall, S. W.

1980-01-01

Average end of charge voltages and pressures, and capacity output in ampere hours are presented. Test limits specify those values at which a cell is to be terminated from charge or discharge. Requirements are based on past cell performance data. The requirement does not constitute a limit for discontinuance from testing. The nickel cadmium batteries were screened for internal shorts, low capacity, electrolyte leakage, or inability of any cell to recover its open circuit voltage above 1.150 volts during the internal short test.

Influence of different yeast cell wall preparations and their components on performance and immune and metabolic pathways in Clostridium perfringens-challenged broiler chicks

USDA-ARS?s Scientific Manuscript database

A study was conducted to evaluate the influence of purification of yeast cell wall (YCW) preparations on broiler performance, and immunogenic and metabolic pathways under microbial challenge. A total of 240 day-of-hatch chicks were distributed among two battery brooder units (48 pens; 5 birds/pen; ...

Evaluation program for secondary spacecraft cells

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1975-01-01

The cycle life tests to determine the performance capabilities of packs of cells under different loads and temperature conditions are reported. Results are summarized, and the failure of 14 failed cells is analyzed. It was found that the main cause of failure was separator deterioration and migration of the negative plate material.

An inventory of aeronautical ground research facilities. Volume 2: Air breathing engine test facilities

NASA Technical Reports Server (NTRS)

Pirrello, C. J.; Hardin, R. D.; Heckart, M. V.; Brown, K. R.

1971-01-01

The inventory covers free jet and direct connect altitude cells, sea level static thrust stands, sea level test cells with ram air, and propulsion wind tunnels. Free jet altitude cells and propulsion wind tunnels are used for evaluation of complete inlet-engine-exhaust nozzle propulsion systems under simulated flight conditions. These facilities are similar in principal of operation and differ primarily in test section concept. The propulsion wind tunnel provides a closed test section and restrains the flow around the test specimen while the free jet is allowed to expand freely. A chamber of large diameter about the free jet is provided in which desired operating pressure levels may be maintained. Sea level test cells with ram air provide controlled, conditioned air directly to the engine face for performance evaluation at low altitude flight conditions. Direct connect altitude cells provide a means of performance evaluation at simulated conditions of Mach number and altitude with air supplied to the flight altitude conditions. Sea level static thrust stands simply provide an instrumented engine mounting for measuring thrust at zero airspeed. While all of these facilities are used for integrated engine testing, a few provide engine component test capability.

Evaluation of anode (electro)catalytic materials for the direct borohydride fuel cell: Methods and benchmarks

NASA Astrophysics Data System (ADS)

Olu, Pierre-Yves; Job, Nathalie; Chatenet, Marian

2016-09-01

In this paper, different methods are discussed for the evaluation of the potential of a given catalyst, in view of an application as a direct borohydride fuel cell DBFC anode material. Characterizations results in DBFC configuration are notably analyzed at the light of important experimental variables which influence the performances of the DBFC. However, in many practical DBFC-oriented studies, these various experimental variables prevent one to isolate the influence of the anode catalyst on the cell performances. Thus, the electrochemical three-electrode cell is a widely-employed and useful tool to isolate the DBFC anode catalyst and to investigate its electrocatalytic activity towards the borohydride oxidation reaction (BOR) in the absence of other limitations. This article reviews selected results for different types of catalysts in electrochemical cell containing a sodium borohydride alkaline electrolyte. In particular, propositions of common experimental conditions and benchmarks are given for practical evaluation of the electrocatalytic activity towards the BOR in three-electrode cell configuration. The major issue of gaseous hydrogen generation and escape upon DBFC operation is also addressed through a comprehensive review of various results depending on the anode composition. At last, preliminary concerns are raised about the stability of potential anode catalysts upon DBFC operation.

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company, 6.0 ampere-hour nickel-cadmium spacecraft cells for the GOES-D, E and F satellite program

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1979-01-01

The tests are to insure that all cells put into the life cycle program are of high quality by the screening of cells found to have electrolyte leakage, internal shorts, low capacity, or inability of any cell to recover its open-circuit voltage above 1.150 volts during the internal short test. Test limits specify those values at which a cell is to be terminated from charge or discharge. Requirements are referenced to normally expected values based on past performance of aerospace nickel-cadmium cells with demonstrated life characteristics. Recommendations for the improvement of the manufacturing processes are presented.

Performance Characteristics of Lithium Ion Polymeric Electrolyte Cells

NASA Technical Reports Server (NTRS)

Shen, D.; Nagasubramanian, G.; Huang, C-K.; Surampudi, S.; Halpert, G.

1994-01-01

A series of polyacrylonitrile-based (PAN) electrolytes containing LiAsF6 and a number of solvent mixtures including ethylene carbonate (EC) + propylene carbonate (PC) were prepared, electrochemically evaluated and used as electrolyte in the polymer cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Black, Billy D.; Akhil, Abbas Ali

This is the final report on a field evaluation by the Department of the Navy of twenty 5-kW PEM fuel cells carried out during 2004 and 2005 at five Navy sites located in New York, California, and Hawaii. The key objective of the effort was to obtain an engineering assessment of their military applications. Particular issues of interest were fuel cell cost, performance, reliability, and the readiness of commercial fuel cells for use as a standalone (grid-independent) power option. Two corollary objectives of the demonstration were to promote technological advances and to improve fuel performance and reliability. From a costmore » perspective, the capital cost of PEM fuel cells at this stage of their development is high compared to other power generation technologies. Sandia National Laboratories technical recommendation to the Navy is to remain involved in evaluating successive generations of this technology, particularly in locations with greater environmental extremes, and it encourages their increased use by the Navy.« less

Atomic layer deposition of ruthenium surface-coating on porous platinum catalysts for high-performance direct ethanol solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Jeong, Heon Jae; Kim, Jun Woo; Jang, Dong Young; Shim, Joon Hyung

2015-09-01

Pt-Ru bi-metallic catalysts are synthesized by atomic layer deposition (ALD) of Ru surface-coating on sputtered Pt mesh. The catalysts are evaluated in direct ethanol solid oxide fuel cells (DESOFCs) in the temperature range of 300-500 °C. Island-growth of the ALD Ru coating is confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy (XPS) analyses. The performance of the DESOFCs is evaluated based on the current-voltage output and electrochemical impedance spectroscopy. Genuine reduction of the polarization impedance, and enhanced power output with improved surface kinetics are achieved with the optimized ALD Ru surface-coating compared to bare Pt. The chemical composition of the Pt/ALD Ru electrode surface after fuel cell operation is analyzed via XPS. Enhanced cell performance is clearly achieved, attributed to the effective Pt/ALD Ru bi-metallic catalysis, including oxidation of Cdbnd O by Ru, and de-protonation of ethanol and cleavage of C-C bonds by Pt, as supported by surface morphology analysis which confirms formation of a large amount of carbon on bare Pt after the ethanol-fuel-cell test.

Bone marrow multipotent mesenchymal stromal cells do not reduce fibrosis or improve function in a rat model of severe chronic liver injury.

PubMed

Carvalho, Adriana B; Quintanilha, Luiz Fernando; Dias, Juliana V; Paredes, Bruno D; Mannheimer, Elida G; Carvalho, Felipe G; Asensi, Karina D; Gutfilen, Bianca; Fonseca, Lea Mirian B; Resende, Celia Maria C; Rezende, Guilherme F M; Takiya, Christina M; de Carvalho, Antonio Carlos Campos; Goldenberg, Regina C S

2008-05-01

The objective of our study was to evaluate the therapeutic potential of bone marrow mesenchymal stromal cells (MSC) in a rat model of severe chronic liver injury. Fourteen female Wistar rats were fed exclusively an alcoholic liquid diet and received intraperitoneal injections of carbon tetrachloride every other day during 15 weeks. After this period, eight animals (MSC group) had 1 x 10(7) cells injected into the portal vein while six animals (placebo group) received vehicle. Blood analysis was performed to evaluate alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin before cell therapy and 1 and 2 months after cell or placebo infusion. Fibrosis was evaluated before and 1 month after cell or placebo injection by liver biopsies. Two months after cell delivery, animals were sacrificed and histological analysis of the livers was performed. Fibrosis was quantified by histomorphometry. Biopsies obtained before cell infusion showed intense collagen deposition and septa interconnecting regenerative nodules. One month after cell injection, this result was unaltered and differences in fibrosis quantification were not found between MSC and placebo groups. ALT and AST returned to normal values 2 weeks after cell or placebo infusion, without significant differences between experimental groups. Two months after cell or placebo injection, albumin had also returned to normal values and histological results were maintained, again without differences between MSC and placebo groups. Therefore, under our experimental conditions, MSC were unable to reduce fibrosis or improve liver function in a rat model of severe chronic liver injury.

Endurance test and evaluation of alkaline water electrolysis cells

NASA Technical Reports Server (NTRS)

Burke, K. A.; Schubert, F. H.

1981-01-01

Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

Performance of PEM fuel cells stack as affected by number of cell and gas flow-rate

NASA Astrophysics Data System (ADS)

Syampurwadi, A.; Onggo, H.; Indriyati; Yudianti, R.

2017-03-01

The proton exchange membrane fuel cell (PEMFC) is a promising technology as an alternative green energy due to its high power density, low operating temperatures, low local emissions, quiet operation and fast start up-shutdown. In order to apply fuel cell as portable power supply, the performance investigation of small number of cells is needed. In this study, PEMFC stacks consisting of 1, 3, 5 and 7-cells with an active area of 25 cm2 per cell have been designed and developed. Their was evaluated in variation of gas flow rate. The membrane electrode assembly (MEA) was prepared by hot-pressing commercial gas diffusion electrodes (Pt loading 0.5 mg/cm2) on pre-treated Nafion 117 membrane. The stacks were constructed using bipolar plates in serpentine pattern and Z-type gas flow configuration. The experimental results were presented as polarization and power output curves which show the effects of varying number of cells and H2/O2 flow-rates on the PEMFC performance. The experimental results showed that not only number of cells and gas flow-rates affected the fuel cells performance, but also the operating temperature as a result of electrochemistry reaction inside the cell.

Investigation of long term storage effects on aerospace nickel-cadmium cell performance

NASA Technical Reports Server (NTRS)

Yi, T. Y.

1986-01-01

A study on evaluation of the long term storage effects on aerospace nickel-cadmium cells currently being performed at NASA/Goddard Space Flight Center (GSFC) is described. A number of cells of 6 Ah and 12 Ah capacities which were stored in shorted condition for 8 to 9 years at the GSFC were selected for this study. These cells will undergo electrical acceptance testing the the GSFC, and life cycling at the NASA Battery Test Facility at the Naval Weapons Facility at the Naval Weapons Support Center (NWSC) in Crane, Indiana; in addition, some cells from the study will undergo destructive analyses.

Investigation of long term storage effects on aerospace nickel-cadmium cell performance

NASA Astrophysics Data System (ADS)

Yi, T. Y.

1986-09-01

A study on evaluation of the long term storage effects on aerospace nickel-cadmium cells currently being performed at NASA/Goddard Space Flight Center (GSFC) is described. A number of cells of 6 Ah and 12 Ah capacities which were stored in shorted condition for 8 to 9 years at the GSFC were selected for this study. These cells will undergo electrical acceptance testing the the GSFC, and life cycling at the NASA Battery Test Facility at the Naval Weapons Facility at the Naval Weapons Support Center (NWSC) in Crane, Indiana; in addition, some cells from the study will undergo destructive analyses.

Evaluation available encapsulation materials for low-cost long-life silicon photovoltaic arrays

NASA Technical Reports Server (NTRS)

Carmichael, D. C.; Gaines, G. B.; Noel, G. T.; Sliemers, F. A.; Nance, G. P.; Bunk, A. R.; Brockway, M. C.

1978-01-01

Experimental evaluation of selected encapsulation designs and materials based on an earlier study which have potential for use in low cost, long-life photovoltaic arrays are reported. The performance of candidate materials and encapsulated cells were evaluated principally for three types of encapsulation designs based on their potentially low materials and processing costs: (1) polymeric coatings, transparent conformal coatings over the cell with a structural-support substrate; (2) polymeric film lamination, cells laminated between two films or sheets of polymeric materials; and (3) glass-covered systems, cells adhesively bonded to a glass cover (superstrate) with a polymeric pottant and a glass or other substrate material. Several other design types, including those utilizing polymer sheet and pottant materials, were also included in the investigation.

Studies on medicinal herbs for cognitive enhancement based on the text mining of Dongeuibogam and preliminary evaluation of its effects.

PubMed

Pak, Malk Eun; Kim, Yu Ri; Kim, Ha Neui; Ahn, Sung Min; Shin, Hwa Kyoung; Baek, Jin Ung; Choi, Byung Tae

2016-02-17

In literature on Korean medicine, Dongeuibogam (Treasured Mirror of Eastern Medicine), published in 1613, represents the overall results of the traditional medicines of North-East Asia based on prior medicinal literature of this region. We utilized this medicinal literature by text mining to establish a list of candidate herbs for cognitive enhancement in the elderly and then performed an evaluation of their effects. Text mining was performed for selection of candidate herbs. Cell viability was determined in HT22 hippocampal cells and immunohistochemistry and behavioral analysis was performed in a kainic acid (KA) mice model in order to observe alterations of hippocampal cells and cognition. Twenty four herbs for cognitive enhancement in the elderly were selected by text mining of Dongeuibogam. In HT22 cells, pretreatment with 3 candidate herbs resulted in significantly reduced glutamate-induced cell death. Panax ginseng was the most neuroprotective herb against glutamate-induced cell death. In the hippocampus of a KA mice model, pretreatment with 11 candidate herbs resulted in suppression of caspase-3 expression. Treatment with 7 candidate herbs resulted in significantly enhanced expression levels of phosphorylated cAMP response element binding protein. Number of proliferated cells indicated by BrdU labeling was increased by treatment with 10 candidate herbs. Schisandra chinensis was the most effective herb against cell death and proliferation of progenitor cells and Rehmannia glutinosa in neuroprotection in the hippocampus of a KA mice model. In a KA mice model, we confirmed improved spatial and short memory by treatment with the 3 most effective candidate herbs and these recovered functions were involved in a higher number of newly formed neurons from progenitor cells in the hippocampus. These established herbs and their combinations identified by text-mining technique and evaluation for effectiveness may have value in further experimental and clinical applications for cognitive enhancement in the elderly. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Preparation and Evaluation of Multi-Layer Anodes of Solid Oxide Fuel Cell

NASA Technical Reports Server (NTRS)

Santiago, Diana; Farmer, Serene C.; Setlock, John A.

2012-01-01

The development of an energy device with abundant energy generation, ultra-high specific power density, high stability and long life is critical for enabling longer missions and for reducing mission costs. Of all different types of fuel cells, the solid oxide fuel cells (SOFC) is a promising high temperature device that can generate electricity as a byproduct of a chemical reaction in a clean way and produce high quality heat that can be used for other purposes. For aerospace applications, a power-to-weight of (is) greater than 1.0 kW/kg is required. NASA has a patented fuel cell technology under development, capable of achieving the 1.0 kW/kg figure of merit. The first step toward achieving these goals is increasing anode durability. The catalyst plays an important role in the fuel cells for power generation, stability, efficiency and long life. Not only the anode composition, but its preparation and reduction are key to achieving better cell performance. In this research, multi-layer anodes were prepared varying the chemistry of each layer to optimize the performance of the cells. Microstructure analyses were done to the new anodes before and after fuel cell operation. The cells' durability and performance were evaluated in 200 hrs life tests in hydrogen at 850 C. The chemistry of the standard nickel anode was modified successfully reducing the anode degradation from 40% to 8.4% in 1000 hrs and retaining its microstructure.

Novel flowcytometry-based approach of malignant cell detection in body fluids using an automated hematology analyzer

PubMed Central

Tabe, Yoko; Takemura, Hiroyuki; Kimura, Konobu; Takahashi, Toshihiro; Yang, Haeun; Tsuchiya, Koji; Konishi, Aya; Uchihashi, Kinya; Horii, Takashi; Ohsaka, Akimichi

2018-01-01

Morphological microscopic examinations of nucleated cells in body fluid (BF) samples are performed to screen malignancy. However, the morphological differentiation is time-consuming and labor-intensive. This study aimed to develop a new flowcytometry-based gating analysis mode “XN-BF gating algorithm” to detect malignant cells using an automated hematology analyzer, Sysmex XN-1000. XN-BF mode was equipped with WDF white blood cell (WBC) differential channel. We added two algorithms to the WDF channel: Rule 1 detects larger and clumped cell signals compared to the leukocytes, targeting the clustered malignant cells; Rule 2 detects middle sized mononuclear cells containing less granules than neutrophils with similar fluorescence signal to monocytes, targeting hematological malignant cells and solid tumor cells. BF samples that meet, at least, one rule were detected as malignant. To evaluate this novel gating algorithm, 92 various BF samples were collected. Manual microscopic differentiation with the May-Grunwald Giemsa stain and WBC count with hemocytometer were also performed. The performance of these three methods were evaluated by comparing with the cytological diagnosis. The XN-BF gating algorithm achieved sensitivity of 63.0% and specificity of 87.8% with 68.0% for positive predictive value and 85.1% for negative predictive value in detecting malignant-cell positive samples. Manual microscopic WBC differentiation and WBC count demonstrated 70.4% and 66.7% of sensitivities, and 96.9% and 92.3% of specificities, respectively. The XN-BF gating algorithm can be a feasible tool in hematology laboratories for prompt screening of malignant cells in various BF samples. PMID:29425230

Novel flowcytometry-based approach of malignant cell detection in body fluids using an automated hematology analyzer.

PubMed

Ai, Tomohiko; Tabe, Yoko; Takemura, Hiroyuki; Kimura, Konobu; Takahashi, Toshihiro; Yang, Haeun; Tsuchiya, Koji; Konishi, Aya; Uchihashi, Kinya; Horii, Takashi; Ohsaka, Akimichi

2018-01-01

Morphological microscopic examinations of nucleated cells in body fluid (BF) samples are performed to screen malignancy. However, the morphological differentiation is time-consuming and labor-intensive. This study aimed to develop a new flowcytometry-based gating analysis mode "XN-BF gating algorithm" to detect malignant cells using an automated hematology analyzer, Sysmex XN-1000. XN-BF mode was equipped with WDF white blood cell (WBC) differential channel. We added two algorithms to the WDF channel: Rule 1 detects larger and clumped cell signals compared to the leukocytes, targeting the clustered malignant cells; Rule 2 detects middle sized mononuclear cells containing less granules than neutrophils with similar fluorescence signal to monocytes, targeting hematological malignant cells and solid tumor cells. BF samples that meet, at least, one rule were detected as malignant. To evaluate this novel gating algorithm, 92 various BF samples were collected. Manual microscopic differentiation with the May-Grunwald Giemsa stain and WBC count with hemocytometer were also performed. The performance of these three methods were evaluated by comparing with the cytological diagnosis. The XN-BF gating algorithm achieved sensitivity of 63.0% and specificity of 87.8% with 68.0% for positive predictive value and 85.1% for negative predictive value in detecting malignant-cell positive samples. Manual microscopic WBC differentiation and WBC count demonstrated 70.4% and 66.7% of sensitivities, and 96.9% and 92.3% of specificities, respectively. The XN-BF gating algorithm can be a feasible tool in hematology laboratories for prompt screening of malignant cells in various BF samples.

In vitro evaluation of three-dimensional single-walled carbon nanotube composites for bone tissue engineering.

PubMed

Gupta, Ashim; Main, Benjamin J; Taylor, Brittany L; Gupta, Manu; Whitworth, Craig A; Cady, Craig; Freeman, Joseph W; El-Amin, Saadiq F

2014-11-01

The purpose of this study was to develop three-dimensional single-walled carbon nanotube composites (SWCNT/PLAGA) using 10-mg single-walled carbon nanotubes (SWCNT) for bone regeneration and to determine the mechanical strength of the composites, and to evaluate the interaction of MC3T3-E1 cells via cell adhesion, growth, survival, proliferation, and gene expression. PLAGA (polylactic-co-glycolic acid) and SWCNT/PLAGA microspheres and composites were fabricated, characterized, and mechanical testing was performed. MC3T3-E1 cells were seeded and cell adhesion/morphology, growth/survival, proliferation, and gene expression analysis were performed to evaluate biocompatibility. Imaging studies demonstrated microspheres with uniform shape and smooth surfaces, and uniform incorporation of SWCNT into PLAGA matrix. The microspheres bonded in a random packing manner while maintaining spacing, thus resembling trabeculae of cancellous bone. Addition of SWCNT led to greater compressive modulus and ultimate compressive strength. Imaging studies revealed that MC3T3-E1 cells adhered, grew/survived, and exhibited normal, nonstressed morphology on the composites. SWCNT/PLAGA composites exhibited higher cell proliferation rate and gene expression compared with PLAGA. These results demonstrate the potential of SWCNT/PLAGA composites for musculoskeletal regeneration, for bone tissue engineering, and are promising for orthopedic applications as they possess the combined effect of increased mechanical strength, cell proliferation, and gene expression. © 2014 Wiley Periodicals, Inc.

A Method for the Evaluation of Thousands of Automated 3D Stem Cell Segmentations

PubMed Central

Bajcsy, Peter; Simon, Mylene; Florczyk, Stephen; Simon, Carl G.; Juba, Derek; Brady, Mary

2016-01-01

There is no segmentation method that performs perfectly with any data set in comparison to human segmentation. Evaluation procedures for segmentation algorithms become critical for their selection. The problems associated with segmentation performance evaluations and visual verification of segmentation results are exaggerated when dealing with thousands of 3D image volumes because of the amount of computation and manual inputs needed. We address the problem of evaluating 3D segmentation performance when segmentation is applied to thousands of confocal microscopy images (z-stacks). Our approach is to incorporate experimental imaging and geometrical criteria, and map them into computationally efficient segmentation algorithms that can be applied to a very large number of z-stacks. This is an alternative approach to considering existing segmentation methods and evaluating most state-of-the-art algorithms. We designed a methodology for 3D segmentation performance characterization that consists of design, evaluation and verification steps. The characterization integrates manual inputs from projected surrogate “ground truth” of statistically representative samples and from visual inspection into the evaluation. The novelty of the methodology lies in (1) designing candidate segmentation algorithms by mapping imaging and geometrical criteria into algorithmic steps, and constructing plausible segmentation algorithms with respect to the order of algorithmic steps and their parameters, (2) evaluating segmentation accuracy using samples drawn from probability distribution estimates of candidate segmentations, and (3) minimizing human labor needed to create surrogate “truth” by approximating z-stack segmentations with 2D contours from three orthogonal z-stack projections and by developing visual verification tools. We demonstrate the methodology by applying it to a dataset of 1253 mesenchymal stem cells. The cells reside on 10 different types of biomaterial scaffolds, and are stained for actin and nucleus yielding 128 460 image frames (on average 125 cells/scaffold × 10 scaffold types × 2 stains × 51 frames/cell). After constructing and evaluating six candidates of 3D segmentation algorithms, the most accurate 3D segmentation algorithm achieved an average precision of 0.82 and an accuracy of 0.84 as measured by the Dice similarity index where values greater than 0.7 indicate a good spatial overlap. A probability of segmentation success was 0.85 based on visual verification, and a computation time was 42.3 h to process all z-stacks. While the most accurate segmentation technique was 4.2 times slower than the second most accurate algorithm, it consumed on average 9.65 times less memory per z-stack segmentation. PMID:26268699

Electrical and Optical Characterization of Sputtered Silicon Dioxide, Indium Tin Oxide, and Silicon Dioxide/Indium Tin Oxide Antireflection Coating on Single-Junction GaAs Solar Cells

PubMed Central

Ho, Wen-Jeng; Lin, Jian-Cheng; Liu, Jheng-Jie; Bai, Wen-Bin; Shiao, Hung-Pin

2017-01-01

This study characterized the electrical and optical properties of single-junction GaAs solar cells coated with antireflective layers of silicon dioxide (SiO2), indium tin oxide (ITO), and a hybrid layer of SiO2/ITO applied using Radio frequency (RF) sputtering. The conductivity and transparency of the ITO film were characterized prior to application on GaAs cells. Reverse saturation-current and ideality factor were used to evaluate the passivation performance of the various coatings on GaAs solar cells. Optical reflectance and external quantum efficiency response were used to evaluate the antireflective performance of the coatings. Photovoltaic current-voltage measurements were used to confirm the efficiency enhancement obtained by the presence of the anti-reflective coatings. The conversion efficiency of the GaAs cells with an ITO antireflective coating (23.52%) exceeded that of cells with a SiO2 antireflective coating (21.92%). Due to lower series resistance and higher short-circuit current-density, the carrier collection of the GaAs cell with ITO coating exceeded that of the cell with a SiO2/ITO coating. PMID:28773063

Performance evaluation of Samsung LABGEO(HC10) Hematology Analyzer.

PubMed

Park, Il Joong; Ahn, Sunhyun; Kim, Young In; Kang, Seon Joo; Cho, Sung Ran

2014-08-01

The Samsung LABGEO(HC10) Hematology Analyzer (LABGEO(HC10)) is a recently developed automated hematology analyzer that uses impedance technologies. The analyzer provides 18 parameters including 3-part differential at a maximum rate of 80 samples per hour. To evaluate the performance of the LABGEO(HC10). We evaluated precision, linearity, carryover, and relationship for complete blood cell count parameters between the LABGEO(HC10) and the LH780 (Beckman Coulter Inc) in a university hospital in Korea according to the Clinical and Laboratory Standards Institute guidelines. Sample stability and differences due to the anticoagulant used (K₂EDTA versus K₃EDTA) were also evaluated. The LABGEO(HC10) showed linearity over a wide range and minimal carryover (<1%) for white blood cell, hemoglobin, red blood cell, and platelet parameters. Correlation between the LABGEO(HC10) and the LH780 was good for all complete blood cell count parameters (R > 0.92) except for mean corpuscular hemoglobin concentration. The bias estimated was acceptable for all parameters investigated except for monocyte count. Most parameters were stable until 24 hours both at room temperature and at 4°C. The difference by anticoagulant type was statistically insignificant for all parameters except for a few red cell parameters. The accurate results achievable and simplicity of operation make the unit recommendable for small to medium-sized laboratories.

A review of polymer electrolyte membrane fuel cell stack testing

NASA Astrophysics Data System (ADS)

Miller, M.; Bazylak, A.

This paper presents an overview of polymer electrolyte membrane fuel cell (PEMFC) stack testing. Stack testing is critical for evaluating and demonstrating the viability and durability required for commercial applications. Single cell performance cannot be employed alone to fully derive the expected performance of PEMFC stacks, due to the non-uniformity in potential, temperature, and reactant and product flow distributions observed in stacks. In this paper, we provide a comprehensive review of the state-of-the art in PEMFC testing. We discuss the main topics of investigation, including single cell vs. stack-level performance, cell voltage uniformity, influence of operating conditions, durability and degradation, dynamic operation, and stack demonstrations. We also present opportunities for future work, including the need to verify the impact of stack size and cell voltage uniformity on performance, determine operating conditions for achieving a balance between electrical efficiency and flooding/dry-out, meet lifetime requirements through endurance testing, and develop a stronger understanding of degradation.

Establishing a Surgical Procedure for Rhesus Epiretinal Scaffold Implantation with HiPSC-Derived Retinal Progenitors

PubMed Central

Luo, Ziming; Li, Kang; Li, Kaijing; Xian, Bikun; Liu, Ying; Yang, Sijing; Xu, Chaochao; Lu, Shoutao; Zhang, Haijun

2018-01-01

Background To develop an effective surgical procedure for cellular scaffold epiretinal implantation in rhesus, facilitating subsequent epiretinal stem cell transplantation. Methods Retinal progenitors were seeded onto a poly(lactic-co-glycolic) acid (PLGA) scaffold. First, the cellular scaffolds were delivered by 18G catheter or retinal forceps into rabbit epiretinal space (n = 50). Then, the cell survival rate was evaluated by Cell Counting Kit-8 (CCK-8). Second, three methods of scaffold fixation, including adhesion after gas-liquid exchange (n = 1), tamponade by hydrogel (n = 1), and fixation by retinal tacks (n = 4), were performed in rhesus monkeys. After one month, fundus photography and SD-OCT were performed to assess the outcomes, and histological examination was performed to evaluate proliferation. Results The cell survival rate was significantly higher in the catheter group. Follow-up examination showed that retinal tack fixation was the only method to maintain the scaffolds attached to host retina for at least 3 weeks, which is the minimal time required for cell integration. Histological staining demonstrated slight glial fibrillary acidic protein (GFAP) accumulation in the retinal tack insertion area. Conclusions The established surgical procedure offers a new insight into research of epiretinal cell replacement therapy in rhesus eyes. The successful delivery and long-term fixation provide a prerequisite for cell migration and integration. PMID:29760741

Evaluation of Mismatch Losses due to Shunts in industrial Silicon Photovoltaic Modules

NASA Astrophysics Data System (ADS)

Somasundaran, P.; Shilpi, M.; Gupta, R.

2017-05-01

In order to achieve higher efficiencies in photovoltaic module technology, it is important to characterize the shunts and other defects which degrade the performance of cells and modules as well as decrease their efficiency. These shunts also affect the reliability of cells and modules. It is important to understand how much fill factor and power loss is caused by the presence of shunts in the module. Shunts not only reduce the module power output, but also affect the I-V characteristics of the cell and hence the characteristics of the shunted cells are different from those of the shunt-free cells connected in the module leading to the mismatch effect. This is an interesting effect which has been systematically investigated in the present work. Moreover, the flow of increased shunt current will give rise to increased temperature in the region of shunt, which will affect the cell and hence module performance. In the present study, the distributed diode model has been extended to the module level and applied to evaluate the electrical mismatch losses and thermal mismatch losses due to shunts in industrial Silicon PV modules.

Microbial Challenge Testing of Single Liquid Cathode Feed Water Electrolysis Cells for the International Space Station (ISS) Oxygen Generator Assembly (OGA)

NASA Technical Reports Server (NTRS)

Roy, Robert J.; Wilson, Mark E.; Diderich, Greg S.; Steele, John W.

2011-01-01

The International Space Station (ISS) Oxygen Generator Assembly (OGA) operational performance may be adversely impacted by microbiological growth and biofilm formation over the electrolysis cell membranes. Biofilms could hinder the transport of water from the bulk fluid stream to the membranes and increase the cell concentration overpotential resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid-cathode feed water electrolysis cells to evaluate operational performance with increasing levels of a mixture of five bacteria isolated from ISS and Space Shuttle potable water systems. Baseline performance of the single water electrolysis cells was determined for approximately one month with deionized water. Monthly performance was also determined following each inoculation of the feed tank with 100, 1000, 10,000 and 100,000 cells/ml of the mixed suspension of test bacteria. Water samples from the feed tank and recirculating water loops for each cell were periodically analyzed for enumeration and speciation of bacteria and total organic carbon. While initially a concern, this test program has demonstrated that the performance of the electrolysis cell is not adversely impacted by feed water containing the five species of bacteria tested at a concentration measured as high as 1,000,000 colony forming units (CFU)/ml. This paper presents the methodologies used in the conduct of this test program along with the performance test results at each level of bacteria concentration.

Microbial Challenge Testing of Single Liquid Cathode Feed Water Electrolysis Cells for the International Space Station (ISS) Oxygen Generator Assembly (OGA)

NASA Technical Reports Server (NTRS)

Diderich, Greg S.; Roy, Robert J.; Steele, John W.; Van Keuren, Steven P.; Wilson, Mark E.

2010-01-01

The International Space Station (ISS) Oxygen Generator Assembly (OGA) operational performance may be adversely impacted by microbiological growth and biofilm formation over the electrolysis cell membranes. Biofilms could hinder the transport of water from the bulk fluid stream to the membranes and increase the cell resistance resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid cathode feed electrolyzer cells to evaluate operational performance with increasing levels of a mixture of five bacteria isolated from ISS and Space Shuttle potable water systems. Baseline performance of the single water electrolysis cells was determined for approximately one month with deionized water. Monthly performance was also determined following each inoculation of the feed tank with 100, 1000, 10,000 and 100,000 cells/ml of the mixed suspension of test bacteria. Water samples from the feed tank and recirculating water loops for each cell were periodically analyzed for enumeration and speciation of bacteria and total organic carbon. While initially a concern, this test program has demonstrated that the performance of the electrolysis cell is not adversely impacted by feed water containing the five species of bacteria tested at a concentration measured as high as 1,000,000 colony forming units (CFU)/ml. This paper presents the methodologies used in the conduct of this test program along with the performance test results at each level of bacteria concentration.

Cell module and fuel conditioner development

NASA Technical Reports Server (NTRS)

Feret, J. M.

1982-01-01

The efforts performed to develop a phosphoric acid fuel cell (PAFC) stack design having a 10 kW power rating for operation at higher than atmospheric pressure based on the existing Mark II design configuration are described. The work involves: (1) Performance of pertinent functional analysis, trade studies and thermodynamic cycle analysis for requirements definition and system operating parameter selection purposes, (2) characterization of fuel cell materials and components, and performance testing and evaluation of the repeating electrode components, (3) establishment of the state-of-the-art manufacturing technology for all fuel cell components at Westinghouse and the fabrication of short stacks of various sites, and (4) development of a 10 kW PAFC stack design for higher pressure operation utilizing the top down systems engineering approach.

Structural design considerations for micromachined solid-oxide fuel cells

NASA Astrophysics Data System (ADS)

Srikar, V. T.; Turner, Kevin T.; Andrew Ie, Tze Yung; Spearing, S. Mark

Micromachined solid-oxide fuel cells (μSOFCs) are among a class of devices being investigated for portable power generation. Optimization of the performance and reliability of such devices requires robust, scale-dependent, design methodologies. In this first analysis, we consider the structural design of planar, electrolyte-supported, μSOFCs from the viewpoints of electrochemical performance, mechanical stability and reliability, and thermal behavior. The effect of electrolyte thickness on fuel cell performance is evaluated using a simple analytical model. Design diagrams that account explicitly for thermal and intrinsic residual stresses are presented to identify geometries that are resistant to fracture and buckling. Analysis of energy loss due to in-plane heat conduction highlights the importance of efficient thermal isolation in microscale fuel cell design.

Real-time and accelerated outdoor endurance testing of solar cells

NASA Technical Reports Server (NTRS)

Forestieri, A. F.; Anagnostou, E.

1977-01-01

Real-time and accelerated outdoor endurance testing was performed on a variety of samples of interest to the National Photovoltaic Conversion Program. The real-time tests were performed at seven different sites and the accelerated tests were performed at one of those sites in the southwestern United States. The purpose of the tests were to help evaluate the lifetime of photovoltaic systems. Three types of samples were tested; transmission samples of possible cover materials, sub-modules constructed using these materials attached to solar cells, and solar cell modules produced by the manufacturers for the ERDA program. Results indicate that suitable cover materials are glass, FEP-A and PFA. Dirt accumulation and cleanability are important factors in the selection of solar cell module covers and encapsulants.

A new hand-held microfluidic cytometer for evaluating irradiation damage by analysis of the damaged cells distribution.

PubMed

Wang, Junsheng; Fan, Zhiqiang; Zhao, Yile; Song, Younan; Chu, Hui; Song, Wendong; Song, Yongxin; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

2016-03-17

Space radiation brings uneven damages to cells. The detection of the distribution of cell damage plays a very important role in radiation medicine and the related research. In this paper, a new hand-held microfluidic flow cytometer was developed to evaluate the degree of radiation damage of cells. The device we propose overcomes the shortcomings (e.g., large volume and high cost) of commercial flow cytometers and can evaluate the radiation damage of cells accurately and quickly with potential for onsite applications. The distribution of radiation-damaged cells is analyzed by a simultaneous detection of immunofluorescence intensity of γ-H2AX and resistance pulse sensor (RPS) signal. The γ-H2AX fluorescence intensity provides information of the degree of radiation damage in cells. The ratio of the number of cells with γ-H2AX fluorescence signals to the total numbers of cells detected by RPS indicates the percentage of the cells that are damaged by radiation. The comparison experiment between the developed hand-held microfluidic flow cytometer and a commercial confocal microscope indicates a consistent and comparable detection performance.

A new hand-held microfluidic cytometer for evaluating irradiation damage by analysis of the damaged cells distribution

NASA Astrophysics Data System (ADS)

Wang, Junsheng; Fan, Zhiqiang; Zhao, Yile; Song, Younan; Chu, Hui; Song, Wendong; Song, Yongxin; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

2016-03-01

Space radiation brings uneven damages to cells. The detection of the distribution of cell damage plays a very important role in radiation medicine and the related research. In this paper, a new hand-held microfluidic flow cytometer was developed to evaluate the degree of radiation damage of cells. The device we propose overcomes the shortcomings (e.g., large volume and high cost) of commercial flow cytometers and can evaluate the radiation damage of cells accurately and quickly with potential for onsite applications. The distribution of radiation-damaged cells is analyzed by a simultaneous detection of immunofluorescence intensity of γ-H2AX and resistance pulse sensor (RPS) signal. The γ-H2AX fluorescence intensity provides information of the degree of radiation damage in cells. The ratio of the number of cells with γ-H2AX fluorescence signals to the total numbers of cells detected by RPS indicates the percentage of the cells that are damaged by radiation. The comparison experiment between the developed hand-held microfluidic flow cytometer and a commercial confocal microscope indicates a consistent and comparable detection performance.

A probabilistic approach to photovoltaic generator performance prediction

NASA Astrophysics Data System (ADS)

Khallat, M. A.; Rahman, S.

1986-09-01

A method for predicting the performance of a photovoltaic (PV) generator based on long term climatological data and expected cell performance is described. The equations for cell model formulation are provided. Use of the statistical model for characterizing the insolation level is discussed. The insolation data is fitted to appropriate probability distribution functions (Weibull, beta, normal). The probability distribution functions are utilized to evaluate the capacity factors of PV panels or arrays. An example is presented revealing the applicability of the procedure.

Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration

NASA Astrophysics Data System (ADS)

Dahal, Lila Raj

Real time spectroscopic ellipsometry (RTSE), and ex-situ mapping spectroscopic ellipsometry (SE) are powerful characterization techniques capable of performance optimization and scale-up evaluation of thin film solar cells used in various photovoltaics technologies. These non-invasive optical probes employ multichannel spectral detection for high speed and provide high precision parameters that describe (i) thin film structure, such as layer thicknesses, and (ii) thin film optical properties, such as oscillator variables in analytical expressions for the complex dielectric function. These parameters are critical for evaluating the electronic performance of materials in thin film solar cells and also can be used as inputs for simulating their multilayer optical performance. In this Thesis, the component layers of thin film hydrogenated silicon (Si:H) solar cells in the n-i-p or substrate configuration on rigid and flexible substrate materials have been studied by RTSE and ex-situ mapping SE. Depositions were performed by magnetron sputtering for the metal and transparent conducting oxide contacts and by plasma enhanced chemical vapor deposition (PECVD) for the semiconductor doped contacts and intrinsic absorber layers. The motivations are first to optimize the thin film Si:H solar cell in n-i-p substrate configuration for single-junction small-area dot cells and ultimately to scale-up the optimized process to larger areas with minimum loss in device performance. Deposition phase diagrams for both i- and p -layers on 2" x 2" rigid borosilicate glass substrate were developed as functions of the hydrogen-to-silane flow ratio in PECVD. These phase diagrams were correlated with the performance parameters of the corresponding solar cells, fabricated in the Cr/Ag/ZnO/n/i/ p/ITO structure. In both cases, optimization was achieved when the layers were deposited in the protocrystalline phase. Identical solar cell structures were fabricated on 6" x 6" borosilicate glass with 256 cells followed by ex-situ mapping SE on each cell to achieve better statistics for solar cell optimization by correlating local structural parameters with solar cell parameters. Solar cells of similar structure were also fabricated on flexible polymer substrates in the roll-to-roll configuration. In this configuration as well, RTSE was demonstrated as an effective process monitoring and control tool for thin film photovoltaics.

Initial evaluation tests of General Electric Company 26.5 ampere-hour nickel-cadmium spacecraft cells with auxiliary electrodes for the TIROS-N and NOAA-A satellites

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1978-01-01

This evaluation test program had the purpose to insure that all cells put into the life cycle program are of high quality by the screening of cells found to have electrolyte leakage, internal shorts, low capacity, or inability of any cell to recover its open-circuit voltage above 1.150 volts during the internal short test. Test limits specify those values at which a cell is to be terminated from charge or discharge. Requirements are referenced to as normally expected values based on past performance of aerospace nickel-cadmium cells with demonstrated life characteristics. A requirement does not constitute a limit for discontinuance from test.

A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

PubMed

Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

2015-12-01

The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Computer model for electrochemical cell performance loss over time in terms of capacity, power, and conductance (CPC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gering, Kevin L.

2015-09-01

Available capacity, power, and cell conductance figure centrally into performance characterization of electrochemical cells (such as Li-ion cells) over their service life. For example, capacity loss in Li-ion cells is due to a combination of mechanisms, including loss of free available lithium, loss of active host sites, shifts in the potential-capacity curve, etc. Further distinctions can be made regarding irreversible and reversible capacity loss mechanisms. There are tandem needs for accurate interpretation of capacity at characterization conditions (cycling rate, temperature, etc.) and for robust self-consistent modeling techniques that can be used for diagnostic analysis of cell data as well asmore » forecasting of future performance. Analogous issues exist for aging effects on cell conductance and available power. To address these needs, a modeling capability was developed that provides a systematic analysis of the contributing factors to battery performance loss over aging and to act as a regression/prediction platform for cell performance. The modeling basis is a summation of self-consistent chemical kinetics rate expressions, which as individual expressions each covers a distinct mechanism (e.g., loss of active host sites, lithium loss), but collectively account for the net loss of premier metrics (e.g., capacity) over time for a particular characterization condition. Specifically, sigmoid-based rate expressions are utilized to describe each contribution to performance loss. Through additional mathematical development another tier of expressions is derived and used to perform differential analyses and segregate irreversible versus reversible contributions, as well as to determine concentration profiles over cell aging for affected Li+ ion inventory and fraction of active sites that remain at each time step. Reversible fade components are surmised by comparing fade rates at fast versus slow cycling conditions. The model is easily utilized for predictive calculations so that future capacity performance can be estimated. The invention covers mathematical and theoretical frameworks, and demonstrates application to various Li-ion cells covering test periods that vary in duration, and shows model predictions well past the end of test periods. Version 2.0 Enhancements: the code now covers path-dependent aging scenarios, wherein the framework allows for arbitrarily-chosen aging conditions over a timeline to accommodate prediction of battery aging over a multiplicity of changing conditions. The code framework also allows for cell conductance and power loss evaluations over cell aging, analysis of series strings that contain a thermal anomaly (hot spot), and evaluation of battery thermal management parameters that impact battery lifetimes. Lastly, a comprehensive GUI now resides in the Ver. 2.0 code.« less

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 12.0 ampere-hour nickel-cadmium spacecraft cells for the international ultraviolet explorer

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1976-01-01

An evaluation test program was conducted to insure that all cells put into the life cycle program are of high quality by the screening of cells found to have electrolyte leakage, internal shorts, low capacity, or inability of any cell to recover its open-circuit voltage above 1.150 volts during the internal short test. The 20 cells were manufactured for the National Aeronautics and Space Administration, Goddard Space Flight Center (GSFC). The cells are from a lot of 175 cells procured for the International Ultraviolet Explorer project. Due to a change in requirements, the project selected to use 6.0 ampere-hour cells. Therefore, the remaining cells of this lot have been placed in storage at GSFC for use on a future GSFC project. All the cells are rated at 12.0 ampere-hours and contain double ceramic seals. Test limits specify those values in which a cell is to be terminated from a particular charge or discharge. Requirements are referred to as normally expected values based on past performance of aerospace nickel cadmium cells with demonstrated life characteristics.

Toxicological evaluation of Cd-based fluorescent nanoprobes by means of in vivo studies

NASA Astrophysics Data System (ADS)

Farias, Patricia M. A.; Ma-Hock, Lan; Landsiedel, Robert; van Ravenzwaay, Bennard

2018-02-01

Cadmium still represents a stigma for many research- and/or industrial applications. Some deleterious effects are attributed to Cadmium. In the present work, highly fluorescent Cadmium sulfide quantum dots are investigated by e.g. physical-chemical characterization. Most important however is their application as fluorescent probes for bio-imaging in living cells and tissues. This work presents their toxicological evaluation by means of in vivo studies. Bio-imaging experiments are performed without any pre-treatment. The toxicological studies performed, strongly indicate that the use of Cadmium based nanoparticles as fluorescent probes may be nonhazardous and not induce side effects for cells/tissues.

Medium energy proton radiation damage to (AlGa)As-GaAs solar cells

NASA Technical Reports Server (NTRS)

Loo, R. Y.; Kamath, G. S.; Knechtli, R. C.

1982-01-01

The performance of (AlGa)As-GaAs solar cells irradiated by medium energy 2, 5, and 10 MeV protons was evaluated. The Si cells without coverglass and a number of GaAs solar cells with 12 mil coverglass were irradiated simultaneously with bare GaAs cells. The cell degradation is directly related to the penetration of depth of protons with GaAs. The influence of periodic and continuous thermal annealing on the GaAs solar cells was investigated.

Automatic microscopy for mitotic cell location.

NASA Technical Reports Server (NTRS)

Herron, J.; Ranshaw, R.; Castle, J.; Wald, N.

1972-01-01

Advances are reported in the development of an automatic microscope with which to locate hematologic or other cells in mitosis for subsequent chromosome analysis. The system under development is designed to perform the functions of: slide scanning to locate metaphase cells; conversion of images of selected cells into binary form; and on-line computer analysis of the digitized image for significant cytogenetic data. Cell detection criteria are evaluated using a test sample of 100 mitotic cells and 100 artifacts.

Radiation Damage Workshop report. [solar cells

NASA Technical Reports Server (NTRS)

Rahilly, W. P.

1980-01-01

The starting material, cell design/geometry, and cell processing/fabrication for silicon and gallium arsenide solar cells are addressed with reference to radiation damage. In general, it is concluded that diagnostic sensitivities and material purities are basic to making significant gains in end-of-life performance and thermal annealability. Further, GaAs material characterization is so sketchy that a well defined program to evaluate such material for solar cell application is needed to maximize GaAs cell technology benefits.

Antidiabetic Mechanisms of Rosa canina Fruits

PubMed Central

Fattahi, Ali; Niyazi, Fatemeh; Shahbazi, Behzad; Farzaei, Mohammad Hosein; Bahrami, Gholamreza

2016-01-01

Rosa canina fruits have been used traditionally for the treatment of diabetes mellitus and its complications. The aim of current study was to evaluate the in vitro mechanism of action of R canina in managing diabetes mellitus. Cell proliferation and cytotoxicity assay were performed on pancreatic β-cells, βTC6. The protective activity of the extract on streptozotocin-induced death in βTC6 cells was studied. The effect of R canina on the metabolism of glucose in HepG2, a hepatocellular carcinoma cell line, was evaluated. The effect of the extract on glucose diffusion across the dialysis membrane, which is a comfortable model for assessing cellular glucose absorption, was evaluated. The results obtained from current study confirmed that R canina extract can act as a growth factor for pancreatic β-cell line providing a novel mechanism for the observed antidiabetic effect of this natural agent. Further preclinical studies are necessary to evaluate the perfect mechanism of action of R canina in diabetes mellitus. PMID:27352916

Variation of solar cell sensitivity and solar radiation on tilted surfaces

NASA Technical Reports Server (NTRS)

Klucher, T. M.

1978-01-01

An empirical study was performed (1) to evaluate the validity of various insolation models used to compute solar radiation incident on tilted surfaces from global data measured on horizontal surfaces and (2) to determine the variation of solar cell sensitivity to solar radiation over a wide range of atmospheric condition. Evaluation of the insolation data indicates that the isotropic sky model of Liu and Jordan underestimates the amount of solar radiation falling on tilted surfaces by as much as 10%. An anisotropic-clear-sky model proposed by Temps and Coulson was also evaluated and found to be deficient under cloudy conditions. A new model, formulated herein, reduced the deviations between measured and predicted insolation to less than 3%. Evaluation of solar cell sensitivity data indicates small change (2-3%) in sensitivity from winter to summer for tilted cells. The feasibility of using such global data as a means for calibrating terrestrial solar cells as done by Treble is discussed.

An assessment of alternative fuel cell designs for residential and commercial cogeneration

NASA Technical Reports Server (NTRS)

Wakefield, R. A.

1980-01-01

A comparative assessment of three fuel cell systems for application in different buildings and geographic locations is presented. The study was performed at the NASA Lewis Center and comprised the fuel cell design, performance in different conditions, and the economic parameters. Applications in multifamily housing, stores and hospitals were considered, with a load of 10kW-1 MW. Designs were traced through system sizing, simulation/evaluation, and reliability analysis, and a computer simulation based on a fourth-order representation of a generalized system was performed. The cells were all phosphoric acid type cells, and were found to be incompatible with gas/electric systems and more favorable economically than the gas/electric systems in hospital uses. The methodology used provided an optimized energy-use pattern and minimized back-up system turn-on.

Teledyne Energy Systems, Inc., Proton Exchange Member (PEM) Fuel Cell Engineering Model Powerplant. Test Report: Initial Benchmark Tests in the Original Orientation

NASA Technical Reports Server (NTRS)

Loyselle, Patricia; Prokopius, Kevin

2011-01-01

Proton Exchange Membrane (PEM) fuel cell technology is the leading candidate to replace the alkaline fuel cell technology, currently used on the Shuttle, for future space missions. During a 5-yr development program, a PEM fuel cell powerplant was developed. This report details the initial performance evaluation test results of the powerplant.

Assessment of Cytotoxic Activity of Rosemary (Rosmarinus officinalis L.), Turmeric (Curcuma longa L.), and Ginger (Zingiber officinale R.) Essential Oils in Cervical Cancer Cells (HeLa).

PubMed

Santos, P A S R; Avanço, G B; Nerilo, S B; Marcelino, R I A; Janeiro, V; Valadares, M C; Machinski, Miguel

2016-01-01

The objective of this study was to evaluate the cytotoxic activity of rosemary (REO, Rosmarinus officinalis L.), turmeric (CEO, Curcuma longa L.), and ginger (GEO, Zingiber officinale R.) essential oils in HeLa cells. Cytotoxicity tests were performed in vitro , using tetrazolium (MTT) and neutral red assays for evaluation of antiproliferative activity by different mechanisms, trypan blue assay to assess cell viability and evaluation of cell morphology for Giemsa to observe the cell damage, and Annexin V to evaluate cell death by apoptosis. CEO and GEO exhibited potent cytotoxic activity against HeLa cells. IC 50 obtained was 36.6  μ g/mL for CEO and 129.9  μ g/mL for GEO. The morphology of HeLa cells showed condensation of chromatin, loss of cell membrane integrity with protrusions (blebs), and cell content leakage for cells treated with CEO and GEO, from the lowest concentrations studied, 32.81  μ g/mL of CEO and 32.12  μ g/mL of GEO. The Annexin V assay revealed a profile of cell death by apoptosis for both CEO and GEO. The results indicate cytotoxic activity in vitro for CEO and GEO, suggesting potential use as anticancer agents for cervical cancer cells.

Assessment of Cytotoxic Activity of Rosemary (Rosmarinus officinalis L.), Turmeric (Curcuma longa L.), and Ginger (Zingiber officinale R.) Essential Oils in Cervical Cancer Cells (HeLa)

PubMed Central

Santos, P. A. S. R.; Avanço, G. B.; Nerilo, S. B.; Marcelino, R. I. A.; Janeiro, V.; Valadares, M. C.

2016-01-01

The objective of this study was to evaluate the cytotoxic activity of rosemary (REO, Rosmarinus officinalis L.), turmeric (CEO, Curcuma longa L.), and ginger (GEO, Zingiber officinale R.) essential oils in HeLa cells. Cytotoxicity tests were performed in vitro, using tetrazolium (MTT) and neutral red assays for evaluation of antiproliferative activity by different mechanisms, trypan blue assay to assess cell viability and evaluation of cell morphology for Giemsa to observe the cell damage, and Annexin V to evaluate cell death by apoptosis. CEO and GEO exhibited potent cytotoxic activity against HeLa cells. IC50 obtained was 36.6 μg/mL for CEO and 129.9 μg/mL for GEO. The morphology of HeLa cells showed condensation of chromatin, loss of cell membrane integrity with protrusions (blebs), and cell content leakage for cells treated with CEO and GEO, from the lowest concentrations studied, 32.81 μg/mL of CEO and 32.12 μg/mL of GEO. The Annexin V assay revealed a profile of cell death by apoptosis for both CEO and GEO. The results indicate cytotoxic activity in vitro for CEO and GEO, suggesting potential use as anticancer agents for cervical cancer cells. PMID:28042599

Direct Simulations of Coupled Transport and Reaction on Nano-Scale X-Ray Computed Tomography Images of Platinum Group Metal-Free Catalyst Cathodes

DOE PAGES

Ogawa, S.; Komini Babu, S.; Chung, H. T.; ...

2016-08-22

The nano/micro-scale geometry of polymer electrolyte fuel cell (PEFC) catalyst layers critically affects cell performance. The small length scales and complex structure of these composite layers make it challenging to analyze cell performance and physics at the particle scale by experiment. We present a computational method to simulate transport and chemical reaction phenomena at the pore/particle-scale and apply it to a PEFC cathode with platinum group metal free (PGM-free) catalyst. Here, we numerically solve the governing equations for the physics with heterogeneous oxygen diffusion coefficient and proton conductivity evaluated using the actual electrode structure and ionomer distribution obtained using nano-scalemore » resolution X-ray computed tomography (nano-CT). Using this approach, the oxygen concentration and electrolyte potential distributions imposed by the oxygen reduction reaction are solved and the impact of the catalyst layer structure on performance is evaluated.« less

Direct Simulations of Coupled Transport and Reaction on Nano-Scale X-Ray Computed Tomography Images of Platinum Group Metal-Free Catalyst Cathodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogawa, S.; Komini Babu, S.; Chung, H. T.

The nano/micro-scale geometry of polymer electrolyte fuel cell (PEFC) catalyst layers critically affects cell performance. The small length scales and complex structure of these composite layers make it challenging to analyze cell performance and physics at the particle scale by experiment. We present a computational method to simulate transport and chemical reaction phenomena at the pore/particle-scale and apply it to a PEFC cathode with platinum group metal free (PGM-free) catalyst. Here, we numerically solve the governing equations for the physics with heterogeneous oxygen diffusion coefficient and proton conductivity evaluated using the actual electrode structure and ionomer distribution obtained using nano-scalemore » resolution X-ray computed tomography (nano-CT). Using this approach, the oxygen concentration and electrolyte potential distributions imposed by the oxygen reduction reaction are solved and the impact of the catalyst layer structure on performance is evaluated.« less

Neural Differentiation of Mesenchymal Stem Cells on Scaffolds for Nerve Tissue Engineering Applications.

PubMed

Quintiliano, Kerlin; Crestani, Thayane; Silveira, Davi; Helfer, Virginia Etges; Rosa, Annelise; Balbueno, Eduardo; Steffens, Daniela; Jotz, Geraldo Pereira; Pilger, Diogo André; Pranke, Patricia

2016-11-01

Scaffolds produced by electrospinning act as supports for cell proliferation and differentiation, improved through the release of neurotrophic factors. The objective of this study was to develop aligned and random nanofiber scaffolds with and without nerve growth factor to evaluate the potential of mesenchymal stem cells (MSCs) for neural differentiation. Nanofiber morphology, diameter, degradability, cell morphology, adhesion, proliferation, viability, cytotoxicity, and neural differentiation were performed to characterize the scaffolds. The expression for nestin, β-III tubulin, and neuron-specific enolase was also evaluated. The scaffolds demonstrated a satisfactory environment for MSC growth, being nontoxic. The MSCs cultivated on the scaffolds were able to adhere and proliferate. The evaluation of neural differentiation indicated that in all groups of scaffolds the MSCs were able to upregulate neural gene expression.

Solar cell array design handbook, volume 1

NASA Technical Reports Server (NTRS)

Rauschenbach, H. S.

1976-01-01

Twelve chapters discuss the following: historical developments, the environment and its effects, solar cells, solar cell filters and covers, solar cell and other electrical interconnections, blocking and shunt diodes, substrates and deployment mechanisms, material properties, design synthesis and optimization, design analysis, procurement, production and cost aspects, evaluation and test, orbital performance, and illustrative design examples. A comprehensive index permits rapid locating of desired topics. The handbook consists of two volumes: Volume 1 is of an expository nature while Volume 2 contains detailed design data in an appendix-like fashion. Volume 2 includes solar cell performance data, applicable unit conversion factors and physical constants, and mechanical, electrical, thermal optical, magnetic, and outgassing material properties. Extensive references are provided.

Super NiCd Open-Circuit Storage and Low Earth Orbit (LEO) Life Test Evaluation

NASA Technical Reports Server (NTRS)

Baer, Jean Marie; Hwang, Warren C.; Ang, Valerie J.; Hayden, Jeff; Rao, Gopalakrishna; Day, John H. (Technical Monitor)

2002-01-01

This presentation discusses Air Force tests performed on super NiCd cells to measure their performance under conditions simulating Low Earth Orbit (LEO) conditions. Super NiCd cells offer potential advantages over existing NiCd cell designs including advanced cell design with improved separator material and electrode making processes, but handling and storage requires active charging. These tests conclude that the super NiCd cells support generic Air Force qualifications for conventional LEO missions (up to five years duration) and that handling and storage may not actually require active charging as previously assumed. Topics covered include: Test Plan, Initial Characterization Tests, Open-Circuit Storage Tests, and post storage capacities.

High-performance Fuel Cell with Stretched Catalyst-Coated Membrane: One-step Formation of Cracked Electrode.

PubMed

Kim, Sang Moon; Ahn, Chi-Yeong; Cho, Yong-Hun; Kim, Sungjun; Hwang, Wonchan; Jang, Segeun; Shin, Sungsoo; Lee, Gunhee; Sung, Yung-Eun; Choi, Mansoo

2016-05-23

We have achieved performance enhancement of polymer electrolyte membrane fuel cell (PEMFC) though crack generation on its electrodes. It is the first attempt to enhance the performance of PEMFC by using cracks which are generally considered as defects. The pre-defined, cracked electrode was generated by stretching a catalyst-coated Nafion membrane. With the strain-stress property of the membrane that is unique in the aspect of plastic deformation, membrane electrolyte assembly (MEA) was successfully incorporated into the fuel cell. Cracked electrodes with the variation of strain were investigated and electrochemically evaluated. Remarkably, mechanical stretching of catalyst-coated Nafion membrane led to a decrease in membrane resistance and an improvement in mass transport, which resulted in enhanced device performance.

Interlaboratory Evaluation of in Vitro Cytotoxicity and Inflammatory Responses to Engineered Nanomaterials: The NIEHS Nano GO Consortium

PubMed Central

Xia, Tian; Hamilton, Raymond F.; Bonner, James C.; Crandall, Edward D.; Elder, Alison; Fazlollahi, Farnoosh; Girtsman, Teri A.; Kim, Kwang; Mitra, Somenath; Ntim, Susana A.; Orr, Galya; Tagmount, Mani; Taylor, Alexia J.; Telesca, Donatello; Tolic, Ana; Vulpe, Christopher D.; Walker, Andrea J.; Wang, Xiang; Witzmann, Frank A.; Wu, Nianqiang; Xie, Yumei; Zink, Jeffery I.; Nel, Andre

2013-01-01

Background: Differences in interlaboratory research protocols contribute to the conflicting data in the literature regarding engineered nanomaterial (ENM) bioactivity. Objectives: Grantees of a National Institute of Health Sciences (NIEHS)-funded consortium program performed two phases of in vitro testing with selected ENMs in an effort to identify and minimize sources of variability. Methods: Consortium program participants (CPPs) conducted ENM bioactivity evaluations on zinc oxide (ZnO), three forms of titanium dioxide (TiO2), and three forms of multiwalled carbon nanotubes (MWCNTs). In addition, CPPs performed bioassays using three mammalian cell lines (BEAS-2B, RLE-6TN, and THP-1) selected in order to cover two different species (rat and human), two different lung epithelial cells (alveolar type II and bronchial epithelial cells), and two different cell types (epithelial cells and macrophages). CPPs also measured cytotoxicity in all cell types while measuring inflammasome activation [interleukin-1β (IL-1β) release] using only THP-1 cells. Results: The overall in vitro toxicity profiles of ENM were as follows: ZnO was cytotoxic to all cell types at ≥ 50 μg/mL, but did not induce IL-1β. TiO2 was not cytotoxic except for the nanobelt form, which was cytotoxic and induced significant IL-1β production in THP-1 cells. MWCNTs did not produce cytotoxicity, but stimulated lower levels of IL-1β production in THP-1 cells, with the original MWCNT producing the most IL-1β. Conclusions: The results provide justification for the inclusion of mechanism-linked bioactivity assays along with traditional cytotoxicity assays for in vitro screening. In addition, the results suggest that conducting studies with multiple relevant cell types to avoid false-negative outcomes is critical for accurate evaluation of ENM bioactivity. PMID:23649538

Lithium-Ion Performance and Abuse Evaluation Using Lithium Technologies 9Ah cell

NASA Technical Reports Server (NTRS)

Hall, Albert Daniel; Jeevarajan, Judith A.

2006-01-01

Lithium-ion batteries in a pouch form offer high energy density and safety in their designs and more recently they are offering performance at higher rates. Lithium Technologies 9Ah high-power pouch cells were studied at different rates, thermal environments, under vacuum and several different conditions of abuse including overcharge, over-discharge and external short circuit. Results of this study will be presented.

OAO-3 end of mission power subsystem evaluation

NASA Technical Reports Server (NTRS)

Tasevoli, M.

1982-01-01

End of mission tests were performed on the OAO-3 power subsystem in three component areas: solar array, nickel-cadmium batteries and the On-Board Processor (OBP) power boost operation. Solar array evaluation consisted of analyzing array performance characteristics and comparing them to earlier flight data. Measured solar array degradation of 14.1 to 17.7% after 8 1/3 years is in good agreement with theortical radiation damage losses. Battery discharge characteristics were compared to results of laboratory life cycle tests performed on similar cells. Comparison of cell voltage profils reveals close correlation and confirms the validity of real time life cycle simulation. The successful operation of the system in the OBP/power boost regulation mode demonstrates the excellent life, reliability and greater system utilization of power subsystems using maximum power trackers.

Evaluation of Ca3Co2O6 as cathode material for high-performance solid-oxide fuel cell

PubMed Central

Wei, Tao; Huang, Yun-Hui; Zeng, Rui; Yuan, Li-Xia; Hu, Xian-Luo; Zhang, Wu-Xing; Jiang, Long; Yang, Jun-You; Zhang, Zhao-Liang

2013-01-01

A cobalt-based thermoelectric compound Ca3Co2O6 (CCO) has been developed as new cathode material with superior performance for intermediate-temperature (IT) solid-oxide fuel cell (SOFC). Systematic evaluation has been carried out. Measurement of thermal expansion coefficient (TEC), thermal-stress (σ) and interfacial shearing stress (τ) with the electrolyte show that CCO matches well with several commonly-used IT electrolytes. Maximum power density as high as 1.47 W cm−2 is attained at 800°C, and an additional thermoelectric voltage of 11.7 mV is detected. The superior electrochemical performance, thermoelectric effect, and comparable thermal and mechanical behaviors with the electrolytes make CCO to be a promising cathode material for SOFC. PMID:23350032

Potential of dynamic spectrum allocation in LTE macro networks

NASA Astrophysics Data System (ADS)

Hoffmann, H.; Ramachandra, P.; Kovács, I. Z.; Jorguseski, L.; Gunnarsson, F.; Kürner, T.

2015-11-01

In recent years Mobile Network Operators (MNOs) worldwide are extensively deploying LTE networks in different spectrum bands and utilising different bandwidth configurations. Initially, the deployment is coverage oriented with macro cells using the lower LTE spectrum bands. As the offered traffic (i.e. the requested traffic from the users) increases the LTE deployment evolves with macro cells expanded with additional capacity boosting LTE carriers in higher frequency bands complemented with micro or small cells in traffic hotspot areas. For MNOs it is crucial to use the LTE spectrum assets, as well as the installed network infrastructure, in the most cost efficient way. The dynamic spectrum allocation (DSA) aims at (de)activating the available LTE frequency carriers according to the temporal and spatial traffic variations in order to increase the overall LTE system performance in terms of total network capacity by reducing the interference. This paper evaluates the DSA potential of achieving the envisaged performance improvement and identifying in which system and traffic conditions the DSA should be deployed. A self-optimised network (SON) DSA algorithm is also proposed and evaluated. The evaluations have been carried out in a hexagonal and a realistic site-specific urban macro layout assuming a central traffic hotspot area surrounded with an area of lower traffic with a total size of approximately 8 × 8 km2. The results show that up to 47 % and up to 40 % possible DSA gains are achievable with regards to the carried system load (i.e. used resources) for homogenous traffic distribution with hexagonal layout and for realistic site-specific urban macro layout, respectively. The SON DSA algorithm evaluation in a realistic site-specific urban macro cell deployment scenario including realistic non-uniform spatial traffic distribution shows insignificant cell throughput (i.e. served traffic) performance gains. Nevertheless, in the SON DSA investigations, a gain of up to 25 % has been observed when analysing the resource utilisation in the non-hotspot cells.

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: UTC FUEL CELLS' PC25C POWER PLANT - GAS PROCESSING UNIT PERFORMANCE FOR ANAEROBIC DIGESTER GAS

EPA Science Inventory

Under EPA’s Environmental Technology Verification program, which provides objective and scientific third party analysis of new technology that can benefit the environment, a combined heat and power system based on the UTC Fuel Cell's PC25C Fuel Cell Power Plant was evaluated. The...

Comparison of Chemical Binding to Recombinant Fathead minnow and Human Estrogen Receptor alpha (ERα) in Whole Cell and Cell-Free Assay Systems.

EPA Science Inventory

Our objectives were to assess whether binding of chemicals differs significantly between recombinant estrogen receptors from fathead minnow (fhERα) and human (hERα) and to evaluate the performance of these receptors using two different in vitro assay systems: a COS whole cell bin...

Evaluation of adhesive penetration of wood fibre by nanoindentation and microscopy

Treesearch

Christopher G. Hunt; Joseph E. Jakes; Warren Grigsby

2010-01-01

Adhesives used in wood products sometimes infiltrate, or diffuse into the solid material of, wood cell walls, potentially modifying their properties. These changes in cell wall properties are likely to impact the performance of adhesive bonds. While adhesive infiltration has been observed by multiple methods, the effect on cell wall properties is not well understood....

VRLA Ultrabattery for high-rate partial-state-of-charge operation

NASA Astrophysics Data System (ADS)

Lam, L. T.; Louey, R.; Haigh, N. P.; Lim, O. V.; Vella, D. G.; Phyland, C. G.; Vu, L. H.; Furukawa, J.; Takada, T.; Monma, D.; Kano, T.

The objective of this study is to produce and test the hybrid valve-regulated Ultrabattery designed specifically for hybrid-electric vehicle duty, i.e., high-rate partial-state-of-charge operation. The Ultrabattery developed by CSIRO Energy Technology is a hybrid energy-storage device, which combines an asymmetric supercapacitor, and a lead-acid battery in one unit cells, taking the best from both technologies without the need for extra, expensive electronic controls. The capacitor will enhance the power and lifespan of the lead-acid battery as it acts as a buffer during high-rate discharging and charging. Consequently, this hybrid technology is able to provide and absorb charge rapidly during vehicle acceleration and braking. The work programme of this study is divided into two main parts, namely, field trial of prototype Ultrabatteries in a Honda Insight HEV and laboratory tests of prototype batteries. In this paper, the performance of prototype Ultrabatteries under different laboratory tests is reported. The evaluation of Ultrabatteries in terms of initial performance and cycling performance has been conducted at both CSIRO and Furukawa laboratories. The initial performance of prototype Ultrabatteries, such as capacity, power, cold cranking and self-discharge has been evaluated based upon the US FreedomCAR Battery Test Manual (DOE/ID-11069, October 2003). Results show that the Ultrabatteries meet, or exceed, respective targets of power, available energy, cold cranking and self-discharge set for both minimum and maximum power-assist HEVs. The cycling performance of prototype Ultrabatteries has been evaluated using: (i) simplified discharge and charge profile to simulate the driving conditions of micro-HEV; (ii) 42-V profile to simulate the driving conditions of mild-HEV and (iii) EUCAR and RHOLAB profiles to simulate the driving conditions of medium-HEV. For comparison purposes, nickel-metal-hydride (Ni-MH) cells, which are presently used in the Honda Insight HEV, have also been subjected to some of the above profiles (i.e., simplified discharge and charge profile and EUCAR profile). Although the Ultrabattery and a Ni-MH cell under EUCAR test profile are still on cycling, the outcomes to date show that the performance of these batteries and cells has been at least four times longer than that of the state-of-the art lead-acid cells or batteries. Excitingly, the performance of Ultrabatteries is proven to be comparable with that of the Ni-MH cells.

Comparative evaluation of performance measures for shading correction in time-lapse fluorescence microscopy.

PubMed

Liu, L; Kan, A; Leckie, C; Hodgkin, P D

2017-04-01

Time-lapse fluorescence microscopy is a valuable technology in cell biology, but it suffers from the inherent problem of intensity inhomogeneity due to uneven illumination or camera nonlinearity, known as shading artefacts. This will lead to inaccurate estimates of single-cell features such as average and total intensity. Numerous shading correction methods have been proposed to remove this effect. In order to compare the performance of different methods, many quantitative performance measures have been developed. However, there is little discussion about which performance measure should be generally applied for evaluation on real data, where the ground truth is absent. In this paper, the state-of-the-art shading correction methods and performance evaluation methods are reviewed. We implement 10 popular shading correction methods on two artificial datasets and four real ones. In order to make an objective comparison between those methods, we employ a number of quantitative performance measures. Extensive validation demonstrates that the coefficient of joint variation (CJV) is the most applicable measure in time-lapse fluorescence images. Based on this measure, we have proposed a novel shading correction method that performs better compared to well-established methods for a range of real data tested. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Mannan-MUC1-pulsed dendritic cell immunotherapy: a phase I trial in patients with adenocarcinoma.

PubMed

Loveland, Bruce E; Zhao, Anne; White, Shane; Gan, Hui; Hamilton, Kate; Xing, Pei-Xiang; Pietersz, Geoffrey A; Apostolopoulos, Vasso; Vaughan, Hilary; Karanikas, Vaios; Kyriakou, Peter; McKenzie, Ian F C; Mitchell, Paul L R

2006-02-01

Tumor antigen-loaded dendritic cells show promise for cancer immunotherapy. This phase I study evaluated immunization with autologous dendritic cells pulsed with mannan-MUC1 fusion protein (MFP) to treat patients with advanced malignancy. Eligible patients had adenocarcinoma expressing MUC1, were of performance status 0 to 1, with no autoimmune disease. Patients underwent leukapheresis to generate dendritic cells by culture ex vivo with granulocyte macrophage colony-stimulating factor and interleukin 4 for 5 days. Dendritic cells were then pulsed overnight with MFP and harvested for reinjection. Patients underwent three cycles of leukapheresis and reinjection at monthly intervals. Patients with clinical benefit were able to continue with dendritic cell-MFP immunotherapy. Ten patients with a range of tumor types were enrolled, with median age of 60 years (range, 33-70 years); eight patients were of performance status 0 and two of performance status 1. Dendritic cell-MFP therapy led to strong T-cell IFNgamma Elispot responses to the vaccine and delayed-type hypersensitivity responses at injection sites in nine patients who completed treatments. Immune responses were sustained at 1 year in monitored patients. Antibody responses were seen in three patients only and were of low titer. Side effects were grade 1 only. Two patients with clearly progressive disease (ovarian and renal carcinoma) at entry were stable after initial therapy and went on to further leukapheresis and dendritic cell-MFP immunotherapy. These two patients have now each completed over 3 years of treatment. Immunization produced T-cell responses in all patients with evidence of tumor stabilization in 2 of the 10 advanced cancer patients treated. These data support further clinical evaluation of this dendritic cell-MFP immunotherapy.

Hydrogen and Fuel Cell Transit Bus Evaluations : Joint Evaluation Plan for the U.S. Department of Energy and the Federal Transit Administration

DOT National Transportation Integrated Search

2008-05-01

This document describes the hydrogen transit bus evaluations performed by the National Renewable Energy Laboratory (NREL) and funded by the U.S. Department of Energy (DOE) and the U.S. Department of Transportations Federal Transit Administration (...

Evaluation of the automated hematology analyzer ADVIA® 120 for cerebrospinal fluid analysis and usage of unique hemolysis reagent.

PubMed

Tanada, H; Ikemoto, T; Masutani, R; Tanaka, H; Takubo, T

2014-02-01

In this study, we evaluated the performance of the ADVIA 120 hematology system for cerebrospinal fluid (CSF) assay. Cell counts and leukocyte differentials in CSF were examined with the ADVIA 120 hematology system, while simultaneously confirming an effective hemolysis agent for automated CSF cell counts. The detection limits of both white blood cell (WBC) counts and red blood cell (RBC) counts on the measurement of CSF cell counts by the ADVIA 120 hematology system were superior at 2 cells/μL (10(-6) L). The WBC count was linear up to 9.850 cells/μL, and the RBC count was linear up to approximately 20 000 cells/μL. The intrarun reproducibility indicated good precision. The leukocyte differential of CSF cells, performed by the ADVIA120 hematology system, showed good correlation with the microscopic procedure. The VersaLyse hemolysis solution efficiently lysed the samples without interfering with cell counts and leukocyte differential, even in a sample that included approximately 50 000/μL RBC. These data show the ADVIA 120 hematology system correctly measured the WBC count and leukocyte differential in CSF. The VersaLyse hemolysis solution is considered to be optimal for hemolysis treatment of CSF when measuring cell counts and differentials by the ADVIA 120 hematology system. © 2013 John Wiley & Sons Ltd.

The role of fetal-maternal microchimerism as a natural-born healer in integrity improvement of maternal damaged kidney.

PubMed

Kajbafzadeh, Abdol-Mohammad; Sabetkish, Shabnam; Sabetkish, Nastaran

2018-01-01

To identify the fetal stem cell (FSC) response to maternal renal injury with emphasis on renal integrity improvement and Y chromosome detection in damaged maternal kidney. Eight non-green fluorescent protein (GFP) transgenic Sprague- Dawley rats were mated with GFP-positive transgenic male rats. Renal damage was induced on the right kidney at gestational day 11. The same procedure was performed in eight non-pregnant rats as control group. Three months after delivery, right nephrectomy was performed in order to evaluate the injured kidney. The fresh perfused kidneys were stained with anti-GFP antibody. Polymerase chain reaction (PCR) assay was also performed for the Y chromosome detection. Cell culture was performed to detect the GFP-positive cells. Technetium-99m-DMSA renal scan and single-photon emission computed tomography (SPECT) were performed after renal damage induction and 3 months later to evaluate the improvement of renal integrity. The presence of FSCs was confirmed by immune histochemical staining as well as immunofluorescent imaging of the damaged part. Gradient PCR of female rat purified DNA demonstrated the presence of Y-chromosome in the damaged maternal kidney. Moreover, the culture of kidney cells showed GPF- positive cells by immunofluorescence microscopy. The acute renal scar was repaired and the integrity of damaged kidney reached to near normal levels in experimental group as shown in DMSA scan. However, no significant improvement was observed in control group. FSC seems to be the main mechanism in repairing of the maternal renal injury during pregnancy as indicated by Y chromosome and GFP-positive cells in the sub-cultured medium. Copyright® by the International Brazilian Journal of Urology.

Evaluating the performance of microbial fuel cells powering electronic devices

NASA Astrophysics Data System (ADS)

Dewan, Alim; Donovan, Conrad; Heo, Deukhyoun; Beyenal, Haluk

A microbial fuel cell (MFC) is capable of powering an electronic device if we store the energy in an external storage device, such as a capacitor, and dispense that energy intermittently in bursts of high-power when needed. Therefore its performance needs to be evaluated using an energy-storing device such as a capacitor which can be charged and discharged rather than other evaluation techniques, such as continuous energy dissipation through a resistor. In this study, we develop a method of testing microbial fuel cell performance based on storing energy in a capacitor. When a capacitor is connected to a MFC it acts like a variable resistor and stores energy from the MFC at a variable rate. In practice the application of this method to testing microbial fuel cells is very challenging and time consuming; therefore we have custom-designed a microbial fuel cell tester (MFCT). The MFCT evaluates the performance of a MFC as a power source. It uses a capacitor as an energy storing device and waits until a desired amount of energy is stored then discharges the capacitor. The entire process is controlled using an analog-to-digital converter (ADC) board controlled by a custom-written computer program. The utility of our method and the MFCT is demonstrated using a laboratory microbial fuel cell (LMFC) and a sediment microbial fuel cell (SMFC). We determine (1) how frequently a MFC can charge a capacitor, (2) which electrode is current-limiting, (3) what capacitor value will allow the maximum harvested energy from a MFC, which is called the "optimum charging capacitor value," and (4) what capacitor charging potential will harvest the maximum energy from a MFC, which is called the "optimum charging potential." Using a LMFC we find that (1) the time needed to charge a 3-F capacitor from 0 to 500 mV is 108 min, (2) the optimum charging capacitor value is 3 F, and (3) the optimum charging potential is 300 mV. Using a SMFC we find that (1) the time needed to charge a 3-F capacitor from 0 to 500 mV is 5 min, (2) the optimum charging capacitor value is 3 F, and (3) the optimum charging potential is 500 mV. Our results demonstrate that the developed method and the MFCT can be used to evaluate and optimize energy harvesting when a MFC is used with a capacitor to power wireless sensors monitoring the environment.

Autofocusing and Polar Body Detection in Automated Cell Manipulation.

PubMed

Wang, Zenan; Feng, Chen; Ang, Wei Tech; Tan, Steven Yih Min; Latt, Win Tun

2017-05-01

Autofocusing and feature detection are two essential processes for performing automated biological cell manipulation tasks. In this paper, we have introduced a technique capable of focusing on a holding pipette and a mammalian cell under a bright-field microscope automatically, and a technique that can detect and track the presence and orientation of the polar body of an oocyte that is rotated at the tip of a micropipette. Both algorithms were evaluated by using mouse oocytes. Experimental results show that both algorithms achieve very high success rates: 100% and 96%. As robust and accurate image processing methods, they can be widely applied to perform various automated biological cell manipulations.

Organic solar cells: evaluation of the stability of P3HT using time-delayed degradation

NASA Astrophysics Data System (ADS)

Poh, Chung-How; Poh, Chung-Kiak; Bryant, Glenn; Belcher, Warwick; Dastoor, Paul

2011-12-01

Despite the fact that the performance of organic solar cells is generally susceptible to degradation by moisture exposure, there has been suggestion that the photoactive layer (P3HT) is surprisingly resilient. This work attempts to confirm the stability of P3HT as an organic solar cell material by deliberately introducing water into the photoactive layer. A dramatic step drop in device performance during cell characterization is observed approximately one day after the device has been fabricated. The time-delayed step drop in output efficiency strongly suggests that moisture has little effect on the P3HT conducting polymer.

Active skin as new haptic interface

NASA Astrophysics Data System (ADS)

Vuong, Nguyen Huu Lam; Kwon, Hyeok Yong; Chuc, Nguyen Huu; Kim, Duksang; An, Kuangjun; Phuc, Vuong Hong; Moon, Hyungpil; Koo, Jachoon; Lee, Youngkwan; Nam, Jae-Do; Choi, Hyouk Ryeol

2010-04-01

In this paper, we present a new haptic interface, called "active skin", which is configured with a tactile sensor and a tactile stimulator in single haptic cell, and multiple haptic cells are embedded in a dielectric elastomer. The active skin generates a wide variety of haptic feel in response to the touch by synchronizing the sensor and the stimulator. In this paper, the design of the haptic cell is derived via iterative analysis and design procedures. A fabrication method dedicated to the proposed device is investigated and a controller to drive multiple haptic cells is developed. In addition, several experiments are performed to evaluate the performance of the active skin.

Cell module and fuel conditioner development

NASA Technical Reports Server (NTRS)

Feret, J. M.

1981-01-01

A phosphoric acid fuel cell (PAFC) stack design having a 10 kW power rating for operation at higher than atmospheric pressure based on the existing Mark II design configuration is described. Functional analysis, trade studies and thermodynamic cycle analysis for requirements definition and system operating parameter selection purposes were performed. Fuel cell materials and components, and performance testing and evaluation of the repeating electrode components were characterized. The state of the art manufacturing technology for all fuel cell components and the fabrication of short stacks of various sites were established. A 10 kW PAFC stack design for higher pressure operation utilizing the top down systems engineering aproach was developed.

Synthesis and Anti-cancer Activity of Novel Thiazolidinone Analogs of 6-Aminoflavone.

PubMed

Moorkoth, Sudheer

2015-01-01

Novel heterocyclic analogs were synthesized by combining a flavone nucleus and thiazolidinone ring in an effort to potentiate the existing anti-cancer activity of flavone. The syntheses of 6-aminoflavone, 6-amino-3-methoxyflavone, 6-amino-3-methoxy-3',4'-dimethxyflavone and their corresponding thiazolidinone analogs were performed. Fifteen novel analogs were synthesized and evaluated for their anti-cancer activity using cell-based assay techniques and in vivo testing. As expected, the analogs improved cytotoxicity and were shown to increase the life span of cancer-bearing mice. Cytotoxicity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays in HeLa, MDA-MB-435, and Vero cell lines. In vivo evaluation of anti-cancer activity performed in albino mice bearing Dalton's ascites carcinoma showed that the new analogs enhanced life span and prevented increases in body weight owing to tumor volumes. Moreover, cell-cycle analysis and Hoechst staining analysis proved the apoptotic potential of these analogs. Preliminary pharmacokinetic evaluation was carried out on the synthesized compounds to determine the lipophilicity and pKa. Lipophilicity was determined using high-performance liquid chromatography and the results showed a direct correlation between the observed anti-cancer activity and log P value, while pKa values indicated the ionizing range which is a prediction tool for solubility and permeability.

Development of advanced fuel cell system, phase 3

NASA Technical Reports Server (NTRS)

Handley, L. M.; Meyer, A. P.; Bell, W. F.

1975-01-01

A multiple task research and development program was performed to improve the weight, life, and performance characteristics of hydrogen-oxygen alkaline fuel cells for advanced power systems. Gradual wetting of the anode structure and subsequent long-term performance loss was determined to be caused by deposition of a silicon-containing material on the anode. This deposit was attributed to degradation of the asbestos matrix, and attention was therefore placed on development of a substitute matrix of potassium titanate. An 80 percent gold 20 percent platinum catalyst cathode was developed which has the same performance and stability as the standard 90 percent gold - 10 percent platinum cathode but at half the loading. A hybrid polysulfone/epoxy-glass fiber frame was developed which combines the resistance to the cell environment of pure polysulfone with the fabricating ease of epoxy-glass fiber laminate. These cell components were evaluated in various configurations of full-size cells. The ways in which the baseline engineering model system would be modified to accommodate the requirements of the space tug application are identified.

Becton-Dickson Model 420 Fluorescence-Activated Cell Sorter (FACS).

DTIC Science & Technology

1986-05-01

respectively) have been associated with certain autoimmune or immunodeficient diseases. The effects of UDMH on Lyt. antigens were previously evaluated...measured in cells from feline leukemia virus (FeLV)-infected cats and normal cat cells. The measurements are performed using the calcium-specific dye...ucavd as a stimulator, which allows for quantitation of " . phagocytosis activity of the cells. c) Quantitation of IL-2 receptor site on feline and murine

Stem-cell therapy for dilated cardiomyopathy: a pilot study evaluating retrograde coronary venous delivery.

PubMed

Pogue, B; Estrada, A H; Sosa-Samper, I; Maisenbacher, H W; Lamb, K E; Mincey, B D; Erger, K E; Conlon, T J

2013-07-01

To evaluate retrograde coronary venous stem-cell delivery for Dobermanns with dilated cardiomyopathy. Retrograde coronary venous delivery of adipose-derived mesenchymal stem cells transduced with tyrosine mutant adeno-associated virus 2 to express stromal-derived factor-1 was performed in Dobermanns with dilated cardiomyopathy. Cases were followed for 2 years and electrocardiograms (ECG), echocardiograms and Holter monitoring were performed. Delivery of cells was feasible in 15 of 15 dogs. One dog died following the development of ventricular fibrillation 24 hours after cell delivery. The remaining 14 dogs were discharged the following day without complications. Echocardiographic measurements of left ventricular size and function showed continued progression of disease. On the basis of Kaplan-Meier product limit estimates, median survival for dogs following stem-cell delivery was 620 days (range of 1-799 days). When including only the occult-dilated cardiomyopathy population and excluding those dogs already in congestive heart failure, median survival was 652 days (range of 46-799 days). Retrograde venous delivery of tyrosine mutant adeno-associated virus 2-stromal-derived factor-1 adipose-derived mesenchymal stem cells appears safe. Stem-cell therapy in dogs with occult-dilated cardiomyopathy does not appear to offer advantage compared to recently published survival data in similarly affected Dobermanns. © 2013 British Small Animal Veterinary Association.

In Vitro/In Vivo Evaluation of Radiolabeled [(99m)Tc(CO)3](+)-Hydroxyurea and Fluorescein Isothiocyanate-Hydroxyurea.

PubMed

Yilmaz, Baris; Teksoz, Serap; Kilcar, Ayfer Yurt; Ucar, Eser; Ichedef, Cigdem; Medine, Emin Ilker; Ari, Kadir

2016-02-01

The aim of current study is to examine hydroxyurea (HU), which is an antineoplastic drug used for the treatment of leukemia, sickle-cell disease, HIV, psoriasis, thrombocythemia, and various neoplastic diseases in two aspects. The active ingredient hydroxyurea was obtained by purification of the capsule form drug, commercially named as HYDREA. Then, [(99m)Tc(CO)3](+)core radiolabeling with HU was performed as first aspect. Quality control studies of (99m)Tc(CO)3-HU complex were performed by thin-layer radiochromatography and high-performance liquid radiochromatography methods. The results demonstrated that the radiolabeling yield was quite high (98.43% ± 2.29%). Also, (99m)Tc(CO)3-HU complex has good stability during the 24-hour period. Biological behavior of (99m)Tc(CO)3-HU complex is evaluated by biodistribution studies on Wistar Albino rats. Fluorescein isothiocyanate (FITC) labeling of HU was performed as second aspect. Fluorometric evaluation of binding efficacy and fluorescence imaging studies on MCF7 and Hela cell lines were carried out. It was thought that the knowledge achieved in this study would contribute to using (99m)Tc(CO)3-HU complex as an imaging agent, which inhibits the DNA synthesis selectively, by inhibiting ribonucleotide reductase enzyme. It was observed that FITC-HU has noteworthy incorporation on both cell lines.

Performance Characterization of High Energy Commercial Lithium-ion Cells

NASA Technical Reports Server (NTRS)

Schneidegger, Brianne T.

2010-01-01

The NASA Glenn Research Center Electrochemistry Branch performed characterization of commercial lithium-ion cells to determine the cells' performance against Exploration Technology Development Program (ETDP) Key Performance Parameters (KPP). The goals of the ETDP Energy Storage Project require significant improvements in the specific energy of lithium-ion technology over the state-of-the-art. This work supports the high energy cell development for the Constellation customer Lunar Surface Systems (LSS). In support of these goals, testing was initiated in September 2009 with high energy cylindrical cells obtained from Panasonic and E-One Moli. Both manufacturers indicated the capability of their cells to deliver specific energy of at least 180 Wh/kg or higher. Testing is being performed at the NASA Glenn Research Center to evaluate the performance of these cells under temperature, rate, and cycling conditions relevant to the ETDP goals for high energy cells. The cell-level specific energy goal for high energy technology is 180 Wh/kg at a C/10 rate and 0 C. The threshold value is 165 Wh/kg. The goal is to operate for at least 2000 cycles at 100 percent DOD with greater than 80 percent capacity retention. The Panasonic NCR18650 cells were able to deliver nearly 200 Wh/kg at the aforementioned conditions. The E-One Moli ICR18650J cells also met the specific energy goal by delivering 183 Wh/kg. Though both cells met the goal for specific energy, this testing was only one portion of the testing required to determine the suitability of commercial cells for the ETDP. The cells must also meet goals for cycle life and safety. The results of this characterization are summarized in this report.

[Evaluation of the Abbott Cell-Dyn Sapphire hematology analyzer].

PubMed

Park, Younhee; Song, Jaewoo; Song, Sungwook; Song, Kyung Soon; Ahn, Mee Suk; Yang, Mi-Sook; Kim, Il; Choi, Jong Rak

2007-06-01

The performance of Cell-Dyn Sapphire (Abbott Diagnostic, USA) was compared to the Bayer Advia 2120 (Bayer Diagnostics, USA), Sysmex XE-2100 (Sysmex Corporation, Japan), and reference microscopy. Three hundred samples for routine CBC and WBC differentials were randomly chosen for a comparison analysis. The Cell-Dyn Sapphire system was evaluated according to the linearity, imprecision, inter-instrument correlations, and white blood cell differential. The CBC parameters (WBC, RBC, hemoglobin and platelet) showed a significant linearity with correlation coefficients greater than 0.99 (P<0.0001). Coefficients of variation (CV) for within-run and differential count of WBC were less than 5% except for Total CV for monocytes, eosinophils, and basophils and within-run CV for low valued eosinophils. The correlation coefficients with manual count were lower in monocytes, eosinophils, and basophils than in neutrophils and lymphocytes. The correlation with other hematology anlayzers was significant exclusive of basophils. These results demonstrate that the Cell-Dyn Sapphire has a good linearity, an acceptable reproducibility, a minimal carryover, and a comparable performance with the sysmex XE-2100 and Advia 2120.

Immunophenotype of infiltrating cells in protocol renal allograft biopsies from tacrolimus-versus cyclosporine-treated patients.

PubMed

Serón, Daniel; O'Valle, Francisco; Moreso, Francesc; Gomà, Montse; Hueso, Miguel; Grinyó, Josep M; Garcia del Moral, Raimundo

2007-03-15

The prevalence of subclinical rejection is lower in patients receiving tacrolimus than in patients treated with cyclosporine. However, it is not known whether this difference is related to the modulation of a specific cell immunophenotype. We perform a two case-one control study in patients treated with tacrolimus (n=44) or cyclosporine (n=22) with a protocol biopsy performed at 4 to 6 months. Immunophenotype of infiltrating cells was evaluated with monoclonal antibodies directed against CD45 (all leukocytes), CD3 (T lymphocytes), CD68 (monocytes/macrophages), and CD20 (B lymphocytes) and expressed as interstitial positive cells/mm(2). The number of interstitial CD45 (290+/-209 vs. 696+/-560; P<0.01), CD3 (121+/-84 vs. 208+/-104; P<0.01), and CD68 (155+/-232 vs. 242+/-280; P<0.05) but not CD20 (137+/-119 vs. 197+/-154) positive cells was lower in tacrolimus-treated patients. T lymphocytes and macrophages interstitial infiltration was reduced in tacrolimus treated patients evaluated with protocol biopsies in comparison to cyclosporine-treated patients.

Thermo-electrochemical instrumentation of cylindrical Li-ion cells

NASA Astrophysics Data System (ADS)

McTurk, Euan; Amietszajew, Tazdin; Fleming, Joe; Bhagat, Rohit

2018-03-01

The performance evaluation and optimisation of commercially available lithium-ion cells is typically based upon their full cell potential and surface temperature measurements, despite these parameters not being fully representative of the electrochemical processes taking place in the core of the cell or at each electrode. Several methods were devised to obtain the cell core temperature and electrode-specific potential profiles of cylindrical Li-ion cells. Optical fibres with Bragg Gratings were found to produce reliable core temperature data, while their small mechanical profile allowed for low-impact instrumentation method. A pure metallic lithium reference electrode insertion method was identified, avoiding interference with other elements of the cell while ensuring good contact, enabling in-situ observations of the per-electrode electrochemical responses. Our thermo-electrochemical instrumentation technique has enabled us to collect unprecedented cell data, and has subsequently been used in advanced studies exploring the real-world performance limits of commercial cells.

The in vitro antitumor activity of vitamins C and K3 against ovarian carcinoma.

PubMed

von Gruenigen, Vivian E; Jamison, James M; Gilloteaux, Jacques; Lorimer, Heather E; Summers, Marcia; Pollard, Robert R; Gwin, Carley A; Summers, Jack L

2003-01-01

The objective was to evaluate the cytotoxic effect and mechanism of action of vitamins C (VC) and K3 (VK3) on ovarian carcinoma. Cytotoxicity assays were performed on ovarian cancer cell lines with VC, VK3 or a VC/VK3 combination. FIC index was employed to evaluate synergism. Flow cytometry was accomplished at 90% cytotoxic doses. Light, transmission electron microscopy and DNA isolation were performed. Antitumor activity was exhibited by both VC, VK3 and VC/VK3. VC/VK3 demonstrated synergistic activity. VC/VK3 may induce a G1 block in the cell cycle. Combined vitamin treatment resulted in cells that maintain apparently intact nuclei while extruding pieces of organelle-free cytoplasm. Degradation of chromosomal DNA was observed. Cell death (autoschizis) displayed characteristics of both apoptosis and necrosis. The cytotoxic effects observed may enable vitamins C and K3 to play an adjuvant role in the treatment of ovarian cancer.

Performances and impedance spectroscopy of Small-molecule bulk heterojunction solar cells based on PtOEP: PCBM

NASA Astrophysics Data System (ADS)

Abuelwafa, A. A.; Dongol, M.; El-Nahass, M. M.; Soga, T.

2018-03-01

Small-molecule bulk heterojunction (SBHJ) solar cells based on platinum octaethylporphyrin (PtOEP) as donor material and phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor were fabricated using spin coating techniques with weight ratios from 1:0.1 to 1:9. The formation of charge transfer complex CTC in the PtOEP: PCBM blend was specified from the redshift of the PtOEP absorption peak after blending with PCBM. The photovoltaic performance for PtOEP: PCBM blends were investigated using the external quantum efficiency (EQE) besides the current density-voltage (J-V) characteristics under illumination100 mW/cm2 (AM1.5G). The BHJ solar cell with PtOEP: PCBM ratio of 1:9 exhibited the best performance. The impedance spectroscopy (IS) was examined in the frequency range from 25 Hz to 1 MHz. The equivalent circuit model was evaluated in details to evaluate the impedance spectroscopy parameters. Dielectric constant {ɛ ^' }, dielectric loss {ɛ ^' ' }} and dielectric modulus were included and discussed in terms of dielectric polarization processes. Dielectric modulus displays the non-Debye relaxation in PtOEP: PCBM BHJ solar cells.

Determination of Protein Expression Level in Cultured Cells by Immunocytochemistry on Paraffin-embedded Cell Blocks.

PubMed

Poojan, Shiv; Kim, Han-Seong; Yoon, Ji-Woon; Sim, Hye Won; Hong, Kyeong-Man

2018-05-20

Immunofluorescent staining is currently the method of choice for determination of protein expression levels in cell-culture systems when morphological information is also necessary. The protocol of immunocytochemical staining on paraffin-embedded cell blocks, presented herein, is an excellent alternative to immunofluorescent staining on non-paraffin-embedded fixed cells. In this protocol, a paraffin cell block from HeLa cells was prepared using the thromboplastin-plasma method, and immunocytochemistry was performed for the evaluation of two proliferation markers, CKAP2 and Ki-67. The nuclei and cytoplasmic morphology of the HeLa cells were well preserved in the cell-block slides. At the same time, the CKAP2 and Ki-67 staining patterns in the immunocytochemistry were quite similar to those in immunohistochemical staining in paraffin cancer tissues. With modified cell-culture conditions, including pre-incubation of HeLa cells under serum-free conditions, the effect could be evaluated while preserving architectural information. In conclusion, immunocytochemistry on paraffin-embedded cell blocks is an excellent alternative to immunofluorescent staining.

Cell penetrating peptides: a comparative transport analysis for 474 sequence motifs.

PubMed

Ramaker, Katrin; Henkel, Maik; Krause, Thorsten; Röckendorf, Niels; Frey, Andreas

2018-11-01

Delivering reagents into cells is a key demand in molecular medicine. The vehicle of choice is often cell penetrating peptides (CPPs), which can ferry conjugated cargo across membranes. Although numerous peptides have been shown to promote such uptake events, there has been no comprehensive comparison of individual performance under standardized conditions. We have devised a method to rapidly analyze the ability of a multitude of CPP conjugates to carry a model cargo into HeLa cells. Sequence information for 474 CPPs was collected from literature sources, and the respective peptides were synthesized and modified with carboxyfluorescein (FAM) as model cargo. All candidates were evaluated in an identical uptake test, and transport was quantified using cellular fluorescence intensities. Substantial differences in the ability to carry the fluorophore into the cells were observed, with transport performance differing by a factor of 70 between the best CPP investigated and cargo alone. Strong correlations were observed between uptake efficiency and both sequence length and the presence of positive net charge. A compilation of the 20 top performers with regard to cargo delivery performance and cell compatibility is provided.

Performance Characteristics of Lithium-Ion Prototype Batteries for Mars Surveyor Program 2001 Lander

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L.; Surampudi, S.; Byers, J.; Marsh, R. A.

2000-01-01

A viewgraph presentation outlines the scientific payload, expected launch date and tasks, and an image of the Mars Surveyor 2001 Lander components. The Lander's battery specifications are given. The program objectives for the Li-ion cells for the Lander are listed, and results performance evaluation and cycle life performance tests are outlined for different temperatures. Cell charge characteristics are described, and test data is presented for charge capacity at varying temperatures. Capacity retention and storage characteristics tests are described and results are shown.

Setting the proportion of CD4+ and CD8+ T-cells co-cultured with canine macrophages infected with Leishmania chagasi.

PubMed

Viana, Kelvinson Fernandes; Aguiar-Soares, Rodrigo Dian Oliveira; Ker, Henrique Gama; Resende, Lucilene Aparecida; Souza-Fagundes, Elaine Maria; Dutra, Walderez Ornelas; Fujiwara, Ricardo Toshio; da Silveira-Lemos, Denise; Sant'Ana, Rita de Cássia Oliveira; Wardini, Amanda Brito; Araújo, Márcio Sobreira Silva; Martins-Filho, Olindo Assis; Reis, Alexandre Barbosa; Giunchetti, Rodolfo Cordeiro

2015-07-30

New methods for evaluating the canine immune system are necessary, not only to monitor immunological disorders, but also to provide insights for vaccine evaluations and therapeutic interventions, reducing the costs of assays using dog models, and provide a more rational way for analyzing the canine immune response. The present study intended to establish an in vitro toll to assess the parasitological/immunological status of dogs, applicable in pre-clinical trials of vaccinology, prognosis follow-up and therapeutics analysis of canine visceral leishmaniasis. We have evaluated the performance of co-culture systems of canine Leishmania chagasi-infected macrophages with different cell ratios of total lymphocytes or purified CD4(+) and CD8(+) T-cells. Peripheral blood mononuclear cells from uninfected dogs were used for the system set up. Employing the co-culture systems of L. chagasi-infected macrophages and purified CD4(+) or CD8(+) T-cell subsets we observed a microenvironment compatible with the expected status of the analyzed dogs. In this context, it was clearly demonstrated that, at this selected T-cell:target ratio, the adaptive immune response of uninfected dogs, composed by L. chagasi-unprimed T-cells was not able to perform the in vitro killing of L. chagasi-infected macrophages. Our data demonstrated that the co-culture system with T-cells from uninfected dogs at 1:5 and 1:2 ratio did not control the infection, yielding to patent in vitro parasitism (≥ 80%), low NO production (≤ 5 μM) and IL-10 modulated (IFN-γ/IL-10 ≤ 2) immunological profile in vitro. CD4(+) or CD8(+) T-cells at 1:5 or 1:2 ratio to L. chagasi-infected macrophages seems to be ideal for in vitro assays. This co-culture system may have great potential as a canine immunological analysis method, as well as in vaccine evaluations, prognosis follow-up and therapeutic interventions. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of nickel-metal hydride cell: An update

NASA Technical Reports Server (NTRS)

Kuwajima, S.; Kusawake, Hiroaki; Nakatani, Kensuke; Yano, Y.

1994-01-01

This paper presents in viewgraph format an overview of NASDA's evaluation of commercial nickel metal-hydride (Ni-MH) cells and the development and testing of Ni-MH cells for use in space. The commercial cells are concluded to be feasible and suitable for use in LEO; for GEO, the durability for overcharge is needed because long-term charge retention is required. For the aerospace Ni-MH cell design, two activation procedures are applied to evaluate the effect of the difference in the amount of overcharge protection and precharge. Specific energy of the Ni-MH cell is nearly accomplished at 50 Wh/kg. Initial characteristics indicate the effect derived from precharge. Thirty-five amp-hour class Ni-MH cells have good performance for LEO cycle of 25 and 40 percent DOD up to 3000 cycles as similar to commercial cells. The effect of the difference in the amount of overcharge protection will appear in life test.

Inosine Released from Dying or Dead Cells Stimulates Cell Proliferation via Adenosine Receptors.

PubMed

Chen, Jin; Chaurio, Ricardo A; Maueröder, Christian; Derer, Anja; Rauh, Manfred; Kost, Andriy; Liu, Yi; Mo, Xianming; Hueber, Axel; Bilyy, Rostyslav; Herrmann, Martin; Zhao, Yi; Muñoz, Luis E

2017-01-01

Many antitumor therapies induce apoptotic cell death in order to cause tumor regression. Paradoxically, apoptotic cells are also known to promote wound healing, cell proliferation, and tumor cell repopulation in multicellular organisms. We aimed to characterize the nature of the regenerative signals concentrated in the micromilieu of dead and dying cells. Cultures of viable melanoma B16F10 cells, mouse fibroblasts, and primary human fibroblast-like synoviocytes (FLS) in the presence of dead and dying cells, their supernatants (SNs), or purified agonists and antagonists were used to evaluate the stimulation of proliferation. Viable cell quantification was performed by either flow cytometry of harvested cells or by crystal violet staining of adherent cells. High-performance liquid chromatography and liquid chromatography coupled with mass spectrometry of cell SNs were deployed to identify the nature of growth-promoting factors. Coimplantation of living cells in the presence of SNs collected from dead and dying cells and specific agonists was used to evaluate tumor growth in vivo . The stimulation of proliferation of few surviving cells by bystander dead cells was confirmed for melanoma cells, mouse fibroblasts, and primary FLS. We found that small soluble molecules present in the protein-free fraction of SNs of dead and dying cells were responsible for the promotion of proliferation. The nucleoside inosine released by dead and dying cells acting via adenosine receptors was identified as putative inducer of proliferation of surviving tumor cells after irradiation and heat treatment. Inosine released by dead and dying cells mediates tumor cell proliferation via purinergic receptors. Therapeutic strategies surmounting this pathway may help to reduce the rate of recurrence after radio- and chemotherapy.

Dissociation of spatial navigation and visual guidance performance in Purkinje cell degeneration (pcd) mutant mice.

PubMed

Goodlett, C R; Hamre, K M; West, J R

1992-04-10

Spatial learning in rodents requires normal functioning of hippocampal and cortical structures. Recent data suggest that the cerebellum may also be essential. Neurological mutant mice with dysgenesis of the cerebellum provide useful models to examine the effects of abnormal cerebellar function. Mice with one such mutation, Purkinje cell degeneration (pcd), in which Purkinje cells degenerate between the third and fourth postnatal weeks, were evaluated for performance of spatial navigation learning and visual guidance learning in the Morris maze swim-escape task. Unaffected littermates and C57BL/6J mice served as controls. Separate groups of pcd and control mice were tested at 30, 50 and 110 days of age. At all ages, pcd mice had severe deficits in distal-cue (spatial) navigation, failing to decrease path lengths over training and failing to express appropriate spatial biases on probe trials. On the proximal-cue (visual guidance) task, whenever performance differences between groups did occur, they were limited to the initial trials. The ability of the pcd mice to perform the proximal-cue but not the distal-cue task indicates that the massive spatial navigation deficit was not due simply to motor dysfunction. Histological evaluations confirmed that the pcd mutation resulted in Purkinje cell loss without significant depletion of cells in the hippocampal formation. These data provide further evidence that the cerebellum is vital for the expression of behavior directed by spatial cognitive processes.

Characterization of three types of silicon solar cells for SEPS Deep Space Mission. Volume 3: Current-voltage characteristics of spectrolab sculptured BSR/P+ (K7), BSR/P+ (K6.5) and BSR (K4.5) cells as a function of temperature and intensity

NASA Technical Reports Server (NTRS)

Whitaker, A. F.; Little, S. A.; Wooden, V. A.; Carter, D. E.; Cothren, B. E.; Torstenson, C. A.

1980-01-01

Three types of high performance silicon solar cells, sculptured BSR/P+(K7), BSR/P+(K6.5) and BSR(K4.5) manufactured by Spectrolab were evaluated for their low temperature and low intensity performance. Sixteen cells of each type were subjected to 11 temperatures and 9 intensities. The sculptured BSR/P+(K7) cells provided the greatest maximum power output both at 1 AU and at LTLI conditions. The average efficiencies of this cell were 14.4 percent at 1 SC/+25 deg C and 18.5 percent at 0.086 SC/-100 deg C.

High efficiency, long life terrestrial solar panel

NASA Technical Reports Server (NTRS)

Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

1977-01-01

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

Evaluation of a low density DNA microarray for small B-cell non-Hodgkin lymphoma differential diagnosis.

PubMed

Gillet, Jean-Pierre; Molina, Thierry Jo; Jamart, Jacques; Gaulard, Philippe; Leroy, Karen; Briere, Josette; Theate, Ivan; Thieblemont, Catherine; Bosly, Andre; Herin, Michel; Hamels, Jacques; Remacle, Jose

2009-03-01

Lymphomas are classified according to the World Health Organisation (WHO) classification which defines subtypes on the basis of clinical, morphological, immunophenotypic, molecular and cytogenetic criteria. Differential diagnosis of the subtypes is sometimes difficult, especially for small B-cell lymphoma (SBCL). Standardisation of molecular genetic assays using multiple gene expression analysis by microarrays could be a useful complement to the current diagnosis. The aim of the present study was to develop a low density DNA microarray for the analysis of 107 genes associated with B-cell non-Hodgkin lymphoma and to evaluate its performance in the diagnosis of SBCL. A predictive tool based on Fisher discriminant analysis using a training set of 40 patients including four different subtypes (follicular lymphoma n = 15, mantle cell lymphoma n = 7, B-cell chronic lymphocytic leukemia n = 6 and splenic marginal zone lymphoma n = 12) was designed. A short additional preliminary analysis to gauge the accuracy of this signature was then performed on an external set of nine patients. Using this model, eight of nine of those samples were classified successfully. This pilot study demonstrates that such a microarray tool may be a promising diagnostic approach for small B-cell non-Hodgkin lymphoma.

A novel approach for extracting viscoelastic parameters of living cells through combination of inverse finite element simulation and Atomic Force Microscopy.

PubMed

Wei, Fanan; Yang, Haitao; Liu, Lianqing; Li, Guangyong

2017-03-01

Dynamic mechanical behaviour of living cells has been described by viscoelasticity. However, quantitation of the viscoelastic parameters for living cells is far from sophisticated. In this paper, combining inverse finite element (FE) simulation with Atomic Force Microscope characterization, we attempt to develop a new method to evaluate and acquire trustworthy viscoelastic index of living cells. First, influence of the experiment parameters on stress relaxation process is assessed using FE simulation. As suggested by the simulations, cell height has negligible impact on shape of the force-time curve, i.e. the characteristic relaxation time; and the effect originates from substrate can be totally eliminated when stiff substrate (Young's modulus larger than 3 GPa) is used. Then, so as to develop an effective optimization strategy for the inverse FE simulation, the parameters sensitivity evaluation is performed for Young's modulus, Poisson's ratio, and characteristic relaxation time. With the experiment data obtained through typical stress relaxation measurement, viscoelastic parameters are extracted through the inverse FE simulation by comparing the simulation results and experimental measurements. Finally, reliability of the acquired mechanical parameters is verified with different load experiments performed on the same cell.

Effects of gamma radiation on cork wastewater: Antioxidant activity and toxicity.

PubMed

Madureira, Joana; Pimenta, Andreia I; Popescu, Larisa; Besleaga, Alexandra; Dias, Maria Inês; Santos, Pedro M P; Melo, Rita; Ferreira, Isabel C F R; Cabo Verde, Sandra; Margaça, Fernanda M A

2017-02-01

A comprehensive assessment of the toxicity and antioxidant activity of cork boiling wastewater and the effects of gamma radiation on these parameters was performed. Antioxidant activity was evaluated using different methodologies as DPPH radical scavenging activity, reducing power and inhibition of β-carotene bleaching. The results have shown that gamma radiation can induce an increase on the antioxidant activity of cork boiling wastewater. Toxicity tests were performed to access the potential added value of the irradiated wastewaters and/or minimization of the impact for discharge in the environment. Two different methods for toxicity evaluation were followed, bacterial growth inhibition test and cytotoxicity assay, in order to predict the behavior of different cells (prokaryotic and eukaryotic) in the presence of cork wastewater. Non-treated cork boiling wastewater seemed to be non-toxic for prokaryotic cells (Pseudomonas fluorescens and Bacillus subtilis) but toxic for eukaryotic cells (A549 human cells and RAW264.7 mouse cells). The gamma radiation treatment at doses of 100 kGy appeared to increase the toxicity of cork compounds for all tested cells, which could be related to a toxic effect of radiolytic products of cork compounds in the wastewaters. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-performance Fuel Cell with Stretched Catalyst-Coated Membrane: One-step Formation of Cracked Electrode

PubMed Central

Kim, Sang Moon; Ahn, Chi-Yeong; Cho, Yong-Hun; Kim, Sungjun; Hwang, Wonchan; Jang, Segeun; Shin, Sungsoo; Lee, Gunhee; Sung, Yung-Eun; Choi, Mansoo

2016-01-01

We have achieved performance enhancement of polymer electrolyte membrane fuel cell (PEMFC) though crack generation on its electrodes. It is the first attempt to enhance the performance of PEMFC by using cracks which are generally considered as defects. The pre-defined, cracked electrode was generated by stretching a catalyst-coated Nafion membrane. With the strain-stress property of the membrane that is unique in the aspect of plastic deformation, membrane electrolyte assembly (MEA) was successfully incorporated into the fuel cell. Cracked electrodes with the variation of strain were investigated and electrochemically evaluated. Remarkably, mechanical stretching of catalyst-coated Nafion membrane led to a decrease in membrane resistance and an improvement in mass transport, which resulted in enhanced device performance. PMID:27210793

Strip cell test and evaluation program

NASA Technical Reports Server (NTRS)

Gitlow, B.; Bell, W. F.; Martin, R. E.

1978-01-01

The performance characteristics of alkaline fuel cells to be used for space power systems were tested. Endurance tests were conducted on the cells during energy conversion operations. A feature of the cells fabricated and tested was the capability to evaporate the product water formed during the energy conversion reaction directly to space vacuum. A fuel cell powerplant incorporating these cells does not require a condenser and a hydrogen recirculating pump water separator to remove the product water. This simplified the fuel cell powerplant system, reduced the systems weight, and reduced the systems parasite power.

Enhanced electrochemical sensing of leukemia cells using drug/lipid co-immobilized on the conducting polymer layer.

PubMed

Gurudatt, N G; Naveen, M Halappa; Ban, Changill; Shim, Yoon-Bo

2016-12-15

Electrochemical biosensors using five anticancer drug and lipid molecules attached on the conducting polymer layer to obtain the orientation of drug molecules toward cancer cells, were evaluated as sensing materials and their performances were compared. Conjugation of the drug molecules with a lipid, phosphatidylcholine (PC) has enhanced the sensitivity towards leukemia cells and differentiates cancer cells from normal cells. The composition of each layer of sensor probe was confirmed by electrochemical and surface characterization experiments. Both impedance spectroscopy and voltammetry show the enhanced interaction of leukemia cells using the drug/lipid modified sensor probe. As the number of leukemia cells increased, the charge transfer resistance (Rct) in impedance spectra increased and the amine oxidation peak current of drug molecules in voltammograms decreased at around 0.7-1.0V. Of test drug molecules, raltitrexed (Rtx) showed the best performance for the cancer cells detection. Cancer and normal cell lines from different origins were examined to evaluate the degree of expression of folate receptors (FR) on cells surface, where cervical HeLa cell line was found to be shown the highest expression of the receptor. Impedance and chronoamperometric experiments for leukemia cell line (Jurkat E6-1) showed linear dynamic ranges of 1.0×10(3)-2.5×10(5) cells/mL and 1.0×10(3)-8.0×10(3) cells/mL with detection limits of 68±5 cells/mL and 21±3 cells/mL, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Performance evaluation of the Sysmex(®) XP-300 in an oncology setting: evaluation and comparison of hematological parameters with the Sysmex(®) XN-3000.

PubMed

van Dievoet, M A; Louagie, H; Ghys, T

2016-10-01

The Sysmex XP-300(®) (XP-300) is a new, fully automated hematology analyzer, designed to generate complete blood counts (CBC) with 3-part differential. In our study, the XP-300 was evaluated as a point-of-care (POC) analyzer in an oncology setting. In which blood samples from patients with different pathologies and treatments, affecting hematopoiesis, were analyzed. Performance was evaluated according to the International Council for Standardization in Haematology (ICSH) guidelines and CLSI protocol H20-A2 . Beside precision, linearity and carry-over, a comparison study with the Sysmex(®) XN-3000 (XN-3000) and a manual reference leukocyte differential was performed. Flagging performance was also evaluated. XP-300 showed excellent precision and linearity results. For within- and between-run precision, the criteria, according to Ricos et al. , were met for all parameters tested, except for platelets in the low level. Less than or equal to 0.5% carry-over was seen for all parameters tested. Comparison studies showed an acceptable correlation with both XN-3000 and the manual reference leukocyte count. A suboptimal flagging performance was demonstrated. In the context of diagnosing cytopenia due to myelosuppressing agents or leukocytosis due to infection, the XP-300 showed good analytical performance. However, in the thrombocytopenic range, precision was suboptimal. In follow-up of hematological malignancies with the occurrence of abnormal cells, we advise verification with a more advanced analyzer or with microscopic review, although further studies with a higher prevalence of abnormal cells are needed. © 2016 John Wiley & Sons Ltd.

Inorganic separator technology program

NASA Technical Reports Server (NTRS)

Smatko, J. S.; Weaver, R. D.; Kalhammer, F. R.

1973-01-01

Testing and failure analyses of silver zinc cells with largely inorganic separators were performed. The results showed that the wet stand and cycle life objective of the silver-zinc cell development program were essentially accomplished and led to recommendations for cell composition, design, and operation that should yield further improvement in wet and cycle life. A series of advanced inorganic materials was successfully developed and formulated into rigid and semiflexible separator samples. Suitable screening tests for evaluation of largely inorganic separators were selected and modified for application to the separator materials. The results showed that many of these formulations are potentially superior to previously used materials and permitted selection of three promising materials for further evaluation in silver-zinc cells.

Modeling and experimental performance of an intermediate temperature reversible solid oxide cell for high-efficiency, distributed-scale electrical energy storage

NASA Astrophysics Data System (ADS)

Wendel, Christopher H.; Gao, Zhan; Barnett, Scott A.; Braun, Robert J.

2015-06-01

Electrical energy storage is expected to be a critical component of the future world energy system, performing load-leveling operations to enable increased penetration of renewable and distributed generation. Reversible solid oxide cells, operating sequentially between power-producing fuel cell mode and fuel-producing electrolysis mode, have the capability to provide highly efficient, scalable electricity storage. However, challenges ranging from cell performance and durability to system integration must be addressed before widespread adoption. One central challenge of the system design is establishing effective thermal management in the two distinct operating modes. This work leverages an operating strategy to use carbonaceous reactant species and operate at intermediate stack temperature (650 °C) to promote exothermic fuel-synthesis reactions that thermally self-sustain the electrolysis process. We present performance of a doped lanthanum-gallate (LSGM) electrolyte solid oxide cell that shows high efficiency in both operating modes at 650 °C. A physically based electrochemical model is calibrated to represent the cell performance and used to simulate roundtrip operation for conditions unique to these reversible systems. Design decisions related to system operation are evaluated using the cell model including current density, fuel and oxidant reactant compositions, and flow configuration. The analysis reveals tradeoffs between electrical efficiency, thermal management, energy density, and durability.

Experimental investigations, modeling, and analyses of high-temperature devices for space applications: Part 1. Final report, June 1996--December 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tournier, J.; El-Genk, M.S.; Huang, L.

1999-01-01

The Institute of Space and Nuclear Power Studies at the University of New Mexico has developed a computer simulation of cylindrical geometry alkali metal thermal-to-electric converter cells using a standard Fortran 77 computer code. The objective and use of this code was to compare the experimental measurements with computer simulations, upgrade the model as appropriate, and conduct investigations of various methods to improve the design and performance of the devices for improved efficiency, durability, and longer operational lifetime. The Institute of Space and Nuclear Power Studies participated in vacuum testing of PX series alkali metal thermal-to-electric converter cells and developedmore » the alkali metal thermal-to-electric converter Performance Evaluation and Analysis Model. This computer model consisted of a sodium pressure loss model, a cell electrochemical and electric model, and a radiation/conduction heat transfer model. The code closely predicted the operation and performance of a wide variety of PX series cells which led to suggestions for improvements to both lifetime and performance. The code provides valuable insight into the operation of the cell, predicts parameters of components within the cell, and is a useful tool for predicting both the transient and steady state performance of systems of cells.« less

Experimental investigations, modeling, and analyses of high-temperature devices for space applications: Part 2. Final report, June 1996--December 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tournier, J.; El-Genk, M.S.; Huang, L.

1999-01-01

The Institute of Space and Nuclear Power Studies at the University of New Mexico has developed a computer simulation of cylindrical geometry alkali metal thermal-to-electric converter cells using a standard Fortran 77 computer code. The objective and use of this code was to compare the experimental measurements with computer simulations, upgrade the model as appropriate, and conduct investigations of various methods to improve the design and performance of the devices for improved efficiency, durability, and longer operational lifetime. The Institute of Space and Nuclear Power Studies participated in vacuum testing of PX series alkali metal thermal-to-electric converter cells and developedmore » the alkali metal thermal-to-electric converter Performance Evaluation and Analysis Model. This computer model consisted of a sodium pressure loss model, a cell electrochemical and electric model, and a radiation/conduction heat transfer model. The code closely predicted the operation and performance of a wide variety of PX series cells which led to suggestions for improvements to both lifetime and performance. The code provides valuable insight into the operation of the cell, predicts parameters of components within the cell, and is a useful tool for predicting both the transient and steady state performance of systems of cells.« less

Non-invasive quality evaluation of confluent cells by image-based orientation heterogeneity analysis.

PubMed

Sasaki, Kei; Sasaki, Hiroto; Takahashi, Atsuki; Kang, Siu; Yuasa, Tetsuya; Kato, Ryuji

2016-02-01

In recent years, cell and tissue therapy in regenerative medicine have advanced rapidly towards commercialization. However, conventional invasive cell quality assessment is incompatible with direct evaluation of the cells produced for such therapies, especially in the case of regenerative medicine products. Our group has demonstrated the potential of quantitative assessment of cell quality, using information obtained from cell images, for non-invasive real-time evaluation of regenerative medicine products. However, image of cells in the confluent state are often difficult to evaluate, because accurate recognition of cells is technically difficult and the morphological features of confluent cells are non-characteristic. To overcome these challenges, we developed a new image-processing algorithm, heterogeneity of orientation (H-Orient) processing, to describe the heterogeneous density of cells in the confluent state. In this algorithm, we introduced a Hessian calculation that converts pixel intensity data to orientation data and a statistical profiling calculation that evaluates the heterogeneity of orientations within an image, generating novel parameters that yield a quantitative profile of an image. Using such parameters, we tested the algorithm's performance in discriminating different qualities of cellular images with three types of clinically important cell quality check (QC) models: remaining lifespan check (QC1), manipulation error check (QC2), and differentiation potential check (QC3). Our results show that our orientation analysis algorithm could predict with high accuracy the outcomes of all types of cellular quality checks (>84% average accuracy with cross-validation). Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Design and evaluation of cellular power converter architectures

NASA Astrophysics Data System (ADS)

Perreault, David John

Power electronic technology plays an important role in many energy conversion and storage applications, including machine drives, power supplies, frequency changers and UPS systems. Increases in performance and reductions in cost have been achieved through the development of higher performance power semiconductor devices and integrated control devices with increased functionality. Manufacturing techniques, however, have changed little. High power is typically achieved by paralleling multiple die in a sing!e package, producing the physical equivalent of a single large device. Consequently, both the device package and the converter in which the device is used continue to require large, complex mechanical structures, and relatively sophisticated heat transfer systems. An alternative to this approach is the use of a cellular power converter architecture, which is based upon the parallel connection of a large number of quasi-autonomous converters, called cells, each of which is designed for a fraction of the system rating. The cell rating is chosen such that single-die devices in inexpensive packages can be used, and the cell fabricated with an automated assembly process. The use of quasi-autonomous cells means that system performance is not compromised by the failure of a cell. This thesis explores the design of cellular converter architectures with the objective of achieving improvements in performance, reliability, and cost over conventional converter designs. New approaches are developed and experimentally verified for highly distributed control of cellular converters, including methods for ripple cancellation and current-sharing control. The performance of these techniques are quantified, and their dynamics are analyzed. Cell topologies suitable to the cellular architecture are investigated, and their use for systems in the 5-500 kVA range is explored. The design, construction, and experimental evaluation of a 6 kW cellular switched-mode rectifier is also addressed. This cellular system implements entirely distributed control, and achieves performance levels unattainable with an equivalent single converter. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Treatment of malignant pleural mesothelioma by fibroblast activation protein-specific re-directed T cells

PubMed Central

2013-01-01

Introduction Malignant pleural mesothelioma (MPM) is an incurable malignant disease, which results from chronic exposition to asbestos in at least 70% of the cases. Fibroblast activation protein (FAP) is predominantly expressed on the surface of reactive tumor-associated fibroblasts as well as on particular cancer types. Because of its expression on the cell surface, FAP is an attractive target for adoptive T cell therapy. T cells can be re-directed by retroviral transfer of chimeric antigen receptors (CAR) against tumor-associated antigens (TAA) and therefore represent a therapeutic strategy of adoptive immunotherapy. Methods To evaluate FAP expression immunohistochemistry was performed in tumor tissue from MPM patients. CD8+ human T cells were retrovirally transduced with an anti-FAP-F19-∆CD28/CD3ζ-CAR. T cell function was evaluated in vitro by cytokine release and cytotoxicity assays. In vivo function was tested with an intraperitoneal xenograft tumor model in immunodeficient mice. Results FAP was found to be expressed in all subtypes of MPM. Additionally, FAP expression was evaluated in healthy adult tissue samples and was only detected in specific areas in the pancreas, the placenta and very weakly for cervix and uterus. Expression of the anti-FAP-F19-∆CD28/CD3ζ-CAR in CD8+ T cells resulted in antigen-specific IFNγ release. Additionally, FAP-specific re-directed T cells lysed FAP positive mesothelioma cells and inflammatory fibroblasts in an antigen-specific manner in vitro. Furthermore, FAP-specific re-directed T cells inhibited the growth of FAP positive human tumor cells in the peritoneal cavity of mice and significantly prolonged survival of mice. Conclusion FAP re-directed CD8+ T cells showed antigen-specific functionality in vitro and in vivo. Furthermore, FAP expression was verified in all MPM histotypes. Therefore, our data support performing a phase I clinical trial in which MPM patients are treated with adoptively transferred FAP-specific re-directed T cells. PMID:23937772

Performances of 250 Amp-hr lithium/thionyl chloride cells

NASA Technical Reports Server (NTRS)

Goualard, Jacques

1991-01-01

A 250 Ah lithium thionyl chloride battery is being developed for a booster rocket engine. Extensive cell testing is running to evaluate functional and safety performances. Some results are presented. The lithium/thionyl chloride batteries were selected for their high energy density (low weight) as compared to other sources. The temperature of a lower weight item will be more sensitive to variations of internal and external heat fluxes than a heavier one. The use of high energy density L/TC batteries is subjected to stringent thermal environments to have benefit of energy density and to stay safe in any conditions. The battery thermal environment and discharge rate have to be adjusted to obtain the right temperature range at cell level, to have the maximum performances. Voltage and capacity are very sensitive to temperature. This temperature is the cell internal actual temperature during discharge. This temperature is directed by external thermal environment and by cell internal heat dissipation, i.e., cell actual voltage.

Macular Ganglion Cell Imaging Study: Covariate Effects on the Spectral Domain Optical Coherence Tomography for Glaucoma Diagnosis.

PubMed

Jeong, Jae Hoon; Choi, Yun Jeong; Park, Ki Ho; Kim, Dong Myung; Jeoung, Jin Wook

2016-01-01

To evaluate the effect of multiple covariates on the diagnostic performance of the Cirrus high-definition optical coherence tomography (HD-OCT) for glaucoma detection. A prospective case-control study was performed and included 173 recently diagnosed glaucoma patients and 63 unaffected individuals from the Macular Ganglion Cell Imaging Study. Regression analysis of receiver operating characteristic were conducted to evaluate the influence of age, spherical equivalent, axial length, optic disc size, and visual field index on the macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) measurements. Disease severity, as measured by visual field index, had a significant effect on the diagnostic performance of all Cirrus HD-OCT parameters. Age, axial length and optic disc size were significantly associated with diagnostic accuracy of average peripapillary RNFL thickness, whereas axial length had a significant effect on the diagnostic accuracy of average GCIPL thickness. Diagnostic performance of the Cirrus HD-OCT may be more accurate in the advanced stages of glaucoma than at earlier stages. A smaller optic disc size was significantly associated with improved the diagnostic ability of average RNFL thickness measurements; however, GCIPL thickness may be less affected by age and optic disc size.

The Use of Gadolinium-Carbon Nanostructures to Magnetically Enhance Stem Cell Retention for Cellular Cardiomyoplasty

PubMed Central

Tran, Lesa A.; Hernández-Rivera, Mayra; Berlin, Ari N.; Zheng, Yi; Sampaio, Luiz; Bové, Christina; Cabreira-Hansen, Maria da Graça; Willerson, James T.; Perin, Emerson C.; Wilson, Lon J.

2014-01-01

In this work, the effectiveness of using Gadonanotubes (GNTs) with an external magnetic field to improve retention of transplanted adult mesenchymal stem cells (MSCs) during cellular cardiomyoplasty was evaluated. As a high-performance T1-weighted magnetic resonance imaging (MRI) cell tracking label, the GNTs are gadolinium-loaded carbon nanotube capsules that render MSCs magnetic when internalized. MSCs were internally labeled with either superparamagnetic GNTs or colloidal diamagnetic lutetium (Lu). In vitro cell rolling assays and ex vivo cardiac perfusion experiments qualitatively demonstrated increased magnetic-assisted retention of GNT-labeled MSCs. Subsequent in vivo epicardial cell injections were performed around a 1.3 T NdFeB ring magnet sutured onto the left ventricle of female juvenile pigs (n = 21). Cell dosage, magnet exposure time, and endpoints were varied to evaluate the safety and efficacy of the proposed therapy. Quantification of retained cells in collected tissues by elemental analysis (Gd or Lu) showed that the external magnet helped retain nearly three times more GNT-labeled MSCs than Lu-labeled cells. The sutured magnet was tolerated for up to 168 hours; however, an inflammatory response to the magnet was noted after 48 hours. These proof-of-concept studies support the feasibility and value of using GNTs as a magnetic nanoparticle facilitator to improve cell retention during cellular cardiomyoplasty. PMID:24148239

Testing activities at the National Battery Test Laboratory

NASA Astrophysics Data System (ADS)

Hornstra, F.; Deluca, W. H.; Mulcahey, T. P.

The National Battery Test Laboratory (NBTL) is an Argonne National Laboratory facility for testing, evaluating, and studying advanced electric storage batteries. The facility tests batteries developed under Department of Energy programs and from private industry. These include batteries intended for future electric vehicle (EV) propulsion, electric utility load leveling (LL), and solar energy storage. Since becoming operational, the NBTL has evaluated well over 1400 cells (generally in the form of three- to six-cell modules, but up to 140-cell batteries) of various technologies. Performance characterization assessments are conducted under a series of charge/discharge cycles with constant current, constant power, peak power, and computer simulated dynamic load profile conditions. Flexible charging algorithms are provided to accommodate the specific needs of each battery under test. Special studies are conducted to explore and optimize charge procedures, to investigate the impact of unique load demands on battery performance, and to analyze the thermal management requirements of battery systems.

Performance evaluation of GDC-SrMoO4-YSZ SOFCs prepared with different pore formers

NASA Astrophysics Data System (ADS)

Hongxin, You; Lian, Peng; Xiaojuan, Wang; Cong, Zhao; Yajun, Guan; Tao, Yu; Lijun, Xu; Abuliti

2018-04-01

The paper aims to evaluate the performance of anodes prepared with different pore formers. Anodic precursor material SrMoO4 was prepared by hard template method. Gd0.2Ce0.8O1.9 (GDC) was introduced to the precursor to prepare composite anode material GDC-SrMoO4-YSZ by wet impregnation method. Cotton-fibers, graphite powder, flour and activated carbon fibers (ACF) were added as pore formers to the anode to prepare the corresponding solid oxide fuel cell (SOFC), respectively. The electrical performance testing was conducted under the methane environment at 800°C. The result showed that the single cell with 5wt% cotton-fibers as anode pore-former performed best with the maximum power density (464.49 mW.cm2). The cross section samples of the test cells indicated that the anode was left with a plenty of continuous long channels because of the burning of cotton-fibers. Thus, the influence of the amount of cotton-fibers (2wt%, 4wt%, 5wt%, 7wt%, 10wt%) of the anode on the performance of SOFC was tested and further analyzed by the scanning electron microscope (SEM). It was indicated that the optimum adding amount of cotton-fibers was 5wt%.

Solid Polymer Electrolyte (SPE) fuel cell technology program

NASA Technical Reports Server (NTRS)

1979-01-01

The overall objectives of the Phase IV Solid Polymer Electrolyte Fuel Cell Technology Program were to: (1) establish fuel cell life and performance at temperatures, pressures and current densities significantly higher than those previously demonstrated; (2) provide the ground work for a space energy storage system based on the solid polymer electrolyte technology (i.e., regenerative H2/O2 fuel cell); (3) design, fabricate and test evaluate a full-scale single cell unit. During this phase, significant progress was made toward the accomplishment of these objectives.

Easily constructed spectroelectrochemical cell for batch and flow injection analyses.

PubMed

Flowers, Paul A; Maynor, Margaret A; Owens, Donald E

2002-02-01

The design and performance of an easily constructed spectroelectrochemical cell suitable for batch and flow injection measurements are described. The cell is fabricated from a commercially available 5-mm quartz cuvette and employs 60 ppi reticulated vitreous carbon as the working electrode, resulting in a reasonable compromise between optical sensitivity and thin-layer electrochemical behavior. The spectroelectrochemical traits of the cell in both batch and flow modes were evaluated using aqueous ferricyanide and compare favorably to those reported previously for similar cells.

Systematic evaluation of sericin protein as a substitute for fetal bovine serum in cell culture.

PubMed

Liu, Liyuan; Wang, Jinhuan; Duan, Shengchang; Chen, Lei; Xiang, Hui; Dong, Yang; Wang, Wen

2016-08-17

Fetal bovine serum (FBS) shows obvious deficiencies in cell culture, such as low batch to batch consistency, adventitious biological contaminant risk, and high cost, which severely limit the development of the cell culture industry. Sericin protein derived from the silkworm cocoon has become increasingly popular due to its diverse and beneficial cell culture characteristics. However, systematic evaluation of sericin as a substitute for FBS in cell culture medium remains limited. In this study, we conducted cellular morphological, physiological, and transcriptomic evaluation on three widely used mammalian cells. Compared with cells cultured in the control, those cultured in sericin-substitute medium showed similar cellular morphology, similar or higher cellular overall survival, lower population doubling time (PDT), and a higher percentage of S-phase with similar G2/G1 ratio, indicating comparable or better cell growth and proliferation. At the transcriptomic level, differentially expressed genes between cells in the two media were mainly enriched in function and biological processes related to cell growth and proliferation, reflecting that genes were activated to facilitate cell growth and proliferation. The results of this study suggest that cells cultured in sericin-substituted medium perform as well as, or even better than, those cultured in FBS-containing medium.

Systematic evaluation of sericin protein as a substitute for fetal bovine serum in cell culture

PubMed Central

Liu, Liyuan; Wang, Jinhuan; Duan, Shengchang; Chen, Lei; Xiang, Hui; Dong, Yang; Wang, Wen

2016-01-01

Fetal bovine serum (FBS) shows obvious deficiencies in cell culture, such as low batch to batch consistency, adventitious biological contaminant risk, and high cost, which severely limit the development of the cell culture industry. Sericin protein derived from the silkworm cocoon has become increasingly popular due to its diverse and beneficial cell culture characteristics. However, systematic evaluation of sericin as a substitute for FBS in cell culture medium remains limited. In this study, we conducted cellular morphological, physiological, and transcriptomic evaluation on three widely used mammalian cells. Compared with cells cultured in the control, those cultured in sericin-substitute medium showed similar cellular morphology, similar or higher cellular overall survival, lower population doubling time (PDT), and a higher percentage of S-phase with similar G2/G1 ratio, indicating comparable or better cell growth and proliferation. At the transcriptomic level, differentially expressed genes between cells in the two media were mainly enriched in function and biological processes related to cell growth and proliferation, reflecting that genes were activated to facilitate cell growth and proliferation. The results of this study suggest that cells cultured in sericin-substituted medium perform as well as, or even better than, those cultured in FBS-containing medium. PMID:27531556

Field validation of protocols developed to evaluate in-line mastitis detection systems.

PubMed

Kamphuis, C; Dela Rue, B T; Eastwood, C R

2016-02-01

This paper reports on a field validation of previously developed protocols for evaluating the performance of in-line mastitis-detection systems. The protocols outlined 2 requirements of these systems: (1) to detect cows with clinical mastitis (CM) promptly and accurately to enable timely and appropriate treatment and (2) to identify cows with high somatic cell count (SCC) to manage bulk milk SCC levels. Gold standard measures, evaluation tests, performance measures, and performance targets were proposed. The current study validated the protocols on commercial dairy farms with automated in-line mastitis-detection systems using both electrical conductivity (EC) and SCC sensor systems that both monitor at whole-udder level. The protocol for requirement 1 was applied on 3 commercial farms. For requirement 2, the protocol was applied on 6 farms; 3 of them had low bulk milk SCC (128×10(3) cells/mL) and were the same farms as used for field evaluation of requirement 1. Three farms with high bulk milk SCC (270×10(3) cells/mL) were additionally enrolled. The field evaluation methodology and results were presented at a workshop including representation from 7 international suppliers of in-line mastitis-detection systems. Feedback was sought on the acceptance of standardized performance evaluation protocols and recommended refinements to the protocols. Although the methodology for requirement 1 was relatively labor intensive and required organizational skills over an extended period, no major issues were encountered during the field validation of both protocols. The validation, thus, proved the protocols to be practical. Also, no changes to the data collection process were recommended by the technology supplier representatives. However, 4 recommendations were made to refine the protocols: inclusion of an additional analysis that ignores small (low-density) clot observations in the definition of CM, extension of the time window from 4 to 5 milkings for timely alerts for CM, setting a maximum number of 10 milkings for the time window to detect a CM episode, and presentation of sensitivity for a larger range of false alerts per 1,000 milkings replacing minimum performance targets. The recommended refinements are discussed with suggested changes to the original protocols. The information presented is intended to inform further debate toward achieving international agreement on standard protocols to evaluate performance of in-line mastitis-detection systems. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Long-term tracking of budding yeast cells in brightfield microscopy: CellStar and the Evaluation Platform.

PubMed

Versari, Cristian; Stoma, Szymon; Batmanov, Kirill; Llamosi, Artémis; Mroz, Filip; Kaczmarek, Adam; Deyell, Matt; Lhoussaine, Cédric; Hersen, Pascal; Batt, Gregory

2017-02-01

With the continuous expansion of single cell biology, the observation of the behaviour of individual cells over extended durations and with high accuracy has become a problem of central importance. Surprisingly, even for yeast cells that have relatively regular shapes, no solution has been proposed that reaches the high quality required for long-term experiments for segmentation and tracking (S&T) based on brightfield images. Here, we present CellStar , a tool chain designed to achieve good performance in long-term experiments. The key features are the use of a new variant of parametrized active rays for segmentation, a neighbourhood-preserving criterion for tracking, and the use of an iterative approach that incrementally improves S&T quality. A graphical user interface enables manual corrections of S&T errors and their use for the automated correction of other, related errors and for parameter learning. We created a benchmark dataset with manually analysed images and compared CellStar with six other tools, showing its high performance, notably in long-term tracking. As a community effort, we set up a website, the Yeast Image Toolkit, with the benchmark and the Evaluation Platform to gather this and additional information provided by others. © 2017 The Authors.

Long-term tracking of budding yeast cells in brightfield microscopy: CellStar and the Evaluation Platform

PubMed Central

Versari, Cristian; Stoma, Szymon; Batmanov, Kirill; Llamosi, Artémis; Mroz, Filip; Kaczmarek, Adam; Deyell, Matt

2017-01-01

With the continuous expansion of single cell biology, the observation of the behaviour of individual cells over extended durations and with high accuracy has become a problem of central importance. Surprisingly, even for yeast cells that have relatively regular shapes, no solution has been proposed that reaches the high quality required for long-term experiments for segmentation and tracking (S&T) based on brightfield images. Here, we present CellStar, a tool chain designed to achieve good performance in long-term experiments. The key features are the use of a new variant of parametrized active rays for segmentation, a neighbourhood-preserving criterion for tracking, and the use of an iterative approach that incrementally improves S&T quality. A graphical user interface enables manual corrections of S&T errors and their use for the automated correction of other, related errors and for parameter learning. We created a benchmark dataset with manually analysed images and compared CellStar with six other tools, showing its high performance, notably in long-term tracking. As a community effort, we set up a website, the Yeast Image Toolkit, with the benchmark and the Evaluation Platform to gather this and additional information provided by others. PMID:28179544

Evaluation of cell sheet application on one wall bone defect in Macaca nemestrina through periostin expression

NASA Astrophysics Data System (ADS)

Tamin, R. Y.; Soeroso, Y.; Amir, L.; Idrus, E.

2017-08-01

Chronic periodontitis is an oral disease in which the destruction of periodontal tissue leads to tooth loss. Regenerative therapy for attachment cannot be applied to one wall bone defects owing to the minimal existing healthy bone. Tissue engineering in the form of cell sheets has been developed to overcome this limitation. In a previous study, cell sheet application to a one wall bone defect in Macaca nemestrina showed good clinical results. To evaluate the effectiveness of cell sheet application histologically, the level of periostin expression in the gingival crevicular fluid (GCF) of M. nemestrina was determined. Periostin is a 90-kDa protein that regulates coordination and interaction for regeneration and tissue repair. A laboratory observation study was performed to see the differences in periostin levels in samples collected from M. nemestrina’s GCF, where a cell sheet was applied to the bone defect. Gel electrophoresis with SDS-PAGE was performed to detect periostin expression based on its molecular weight and to compare the expression band between the cell sheet and the control at 1, 2, and 3 weeks after treatment. The gel electrophoresis result shows different thicknesses of the protein band around the molecular weight of periostin between the cell sheet groups.

Amorphous silicon research. Final technical progress report, 1 August 1994--28 February 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guha, S

1998-05-01

This report describes the status and accomplishments of work performed under this subcontract by United Solar Systems. United Solar researchers explored several new deposition regimes/conditions to investigate their effect on material/device performance. To facilitate optimum ion bombardment during growth, a large parameter space involving chamber pressure, rf power, and hydrogen dilution were investigated. United Solar carried out a series of experiments using discharge modulation at various pulsed-plasma intervals to study the effect of Si-particle incorporation on solar cell performance. Hydrogen dilution during deposition is found to improve both the initial and stable performance of a-Si and a-SiGe alloy cells. Researchersmore » conducted a series of temperature-ramping experiments on samples prepared with high and low hydrogen dilutions to study the effect of hydrogen effusion on solar cell performance. Using an internal photoemission method, the electrical bandgap of a microcrystalline p layer used in high-efficiency solar cells was measured to be 1.6 eV. New measurement techniques were developed to evaluate the interface and bulk contributions of losses to solar cell performance. Researchers replaced hydrogen with deuterium and found deuterated amorphous silicon alloy solar cells exhibit reduced light-induced degradation. The incorporation of a microcrystalline n layer in a multijunction cell is seen to improve cell performance. United Solar achieved a world-record single-junction a-Si alloy stable cell efficiency of 9.2% with an active area of 0.25 cm{sup 2} grown with high hydrogen dilution. They also achieved a world-record triple-junction, stable, active-area cell efficiency of 13.0% with an active area of 0.25 cm{sup 2}.« less

Fast globally optimal segmentation of cells in fluorescence microscopy images.

PubMed

Bergeest, Jan-Philip; Rohr, Karl

2011-01-01

Accurate and efficient segmentation of cells in fluorescence microscopy images is of central importance for the quantification of protein expression in high-throughput screening applications. We propose a new approach for segmenting cell nuclei which is based on active contours and convex energy functionals. Compared to previous work, our approach determines the global solution. Thus, the approach does not suffer from local minima and the segmentation result does not depend on the initialization. We also suggest a numeric approach for efficiently computing the solution. The performance of our approach has been evaluated using fluorescence microscopy images of different cell types. We have also performed a quantitative comparison with previous segmentation approaches.

Li-Ion Cell Development for Low Temperature Applications

NASA Technical Reports Server (NTRS)

Huang, C.-K.; Sakamoto, J. S.; Surampudi, S.; Wolfenstine, J.

2000-01-01

JPL is involved in the development of rechargeable Li-ion cells for future Mars Exploration Missions. The specific objectives are to improve the Li-ion cell cycle life performance and rate capability at low temperature (<<-20 C) in order to enhance survivability of the Mars lander and rover batteries. Poor Li-ion rate capability at low temperature has been attributed to: (1) the electrolytes becoming viscous or freezing and/or (2) reduced electrode capacity that results from decreased Li diffusivity. Our efforts focus on increasing the rate capability at low temperature for Li-ion cells. In order to improve the rate capability we evaluated the following: (1) cathode performance at low temperatures, (2) electrode active material particle size on low temperature performance and (3) Li diffusivity at room temperature and low temperatures. In this paper, we will discuss the results of our study.

Application of Vacancy Injection Gettering to Improve Efficiency of Solar Cells Produced by Millinet Solar: Cooperative Research and Development Final Report, CRADA Number CRD-10-417

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sopori, B.

2012-07-01

NREL will apply vacancy injection gettering (VIG) to Millinet solar cells and evaluate the performance improvement produced by this process step. The VIG will be done in conjunction with the formation of a back, Al-alloyed, contact. Millinet Solar will provide NREL with cells having AR coating on the front side and screen-printed Al on the backside, which will be processed in the NREL's optical furnace to perform simultaneous VIG and back contact alloying with deep BSF. These cells will be sent back to Millinet solar for a screen-printed front/side contact mask, followed by a second firing at NREL. Detailed analysesmore » will be performed to determine improvements due to BSF and VIG.« less

Development of a Solid-Oxide Fuel Cell/Gas Turbine Hybrid System Model for Aerospace Applications

NASA Technical Reports Server (NTRS)

Freeh, Joshua E.; Pratt, Joseph W.; Brouwer, Jacob

2004-01-01

Recent interest in fuel cell-gas turbine hybrid applications for the aerospace industry has led to the need for accurate computer simulation models to aid in system design and performance evaluation. To meet this requirement, solid oxide fuel cell (SOFC) and fuel processor models have been developed and incorporated into the Numerical Propulsion Systems Simulation (NPSS) software package. The SOFC and reformer models solve systems of equations governing steady-state performance using common theoretical and semi-empirical terms. An example hybrid configuration is presented that demonstrates the new capability as well as the interaction with pre-existing gas turbine and heat exchanger models. Finally, a comparison of calculated SOFC performance with experimental data is presented to demonstrate model validity. Keywords: Solid Oxide Fuel Cell, Reformer, System Model, Aerospace, Hybrid System, NPSS

Evaluation of the osteogenic differentiation of gingiva-derived stem cells grown on culture plates or in stem cell spheroids: Comparison of two- and three-dimensional cultures.

PubMed

Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2017-09-01

Three-dimensional cell culture systems provide a convenient in vitro model for the study of complex cell-cell and cell-matrix interactions in the absence of exogenous substrates. The current study aimed to evaluate the osteogenic differentiation potential of gingiva-derived stem cells cultured in two-dimensional or three-dimensional systems. To the best of our knowledge, the present study is the first to compare the growth of gingiva-derived stem cells in monolayer culture to a three-dimensional culture system with microwells. For three-dimensional culture, gingiva-derived stem cells were isolated and seeded into polydimethylsiloxane-based concave micromolds. Alkaline phosphatase activity and alizarin red S staining assays were then performed to evaluate osteogenesis and the degree of mineralization, respectively. Stem cell spheroids had a significantly increased level of alkaline phosphatase activity and mineralization compared with cells from the two-dimensional culture. In addition, an increase in mineralized deposits was observed with an increase in the loading cell number. The results of present study indicate that gingiva-derived stem cell spheroids exhibit an increased osteogenic potential compared with stem cells from two-dimensional culture. This highlights the potential of three-dimensional culture systems using gingiva-derived stem cells for regenerative medicine applications requiring stem cells with osteogenic potential.

Parallel affinity-based isolation of leukocyte subsets using microfluidics: application for stroke diagnosis.

PubMed

Pullagurla, Swathi R; Witek, Małgorzata A; Jackson, Joshua M; Lindell, Maria A M; Hupert, Mateusz L; Nesterova, Irina V; Baird, Alison E; Soper, Steven A

2014-04-15

We report the design and performance of a polymer microfluidic device that can affinity select multiple types of biological cells simultaneously with sufficient recovery and purity to allow for the expression profiling of mRNA isolated from these cells. The microfluidic device consisted of four independent selection beds with curvilinear channels that were 25 μm wide and 80 μm deep and were modified with antibodies targeting antigens specifically expressed by two different cell types. Bifurcated and Z-configured device geometries were evaluated for cell selection. As an example of the performance of these devices, CD4+ T-cells and neutrophils were selected from whole blood as these cells are known to express genes found in stroke-related expression profiles that can be used for the diagnosis of this disease. CD4+ T-cells and neutrophils were simultaneously isolated with purities >90% using affinity-based capture in cyclic olefin copolymer (COC) devices with a processing time of ∼3 min. In addition, sufficient quantities of the cells could be recovered from a 50 μL whole blood input to allow for reverse transcription-polymerase chain reaction (RT-PCR) following cell lysis. The expression of genes from isolated T-cells and neutrophils, such as S100A9, TCRB, and FPR1, was evaluated using RT-PCR. The modification and isolation procedures demonstrated here can also be used to analyze other cell types as well where multiple subsets must be interrogated.

A Stereological Method for the Quantitative Evaluation of Cartilage Repair Tissue

PubMed Central

Nyengaard, Jens Randel; Lind, Martin; Spector, Myron

2015-01-01

Objective To implement stereological principles to develop an easy applicable algorithm for unbiased and quantitative evaluation of cartilage repair. Design Design-unbiased sampling was performed by systematically sectioning the defect perpendicular to the joint surface in parallel planes providing 7 to 10 hematoxylin–eosin stained histological sections. Counting windows were systematically selected and converted into image files (40-50 per defect). The quantification was performed by two-step point counting: (1) calculation of defect volume and (2) quantitative analysis of tissue composition. Step 2 was performed by assigning each point to one of the following categories based on validated and easy distinguishable morphological characteristics: (1) hyaline cartilage (rounded cells in lacunae in hyaline matrix), (2) fibrocartilage (rounded cells in lacunae in fibrous matrix), (3) fibrous tissue (elongated cells in fibrous tissue), (4) bone, (5) scaffold material, and (6) others. The ability to discriminate between the tissue types was determined using conventional or polarized light microscopy, and the interobserver variability was evaluated. Results We describe the application of the stereological method. In the example, we assessed the defect repair tissue volume to be 4.4 mm3 (CE = 0.01). The tissue fractions were subsequently evaluated. Polarized light illumination of the slides improved discrimination between hyaline cartilage and fibrocartilage and increased the interobserver agreement compared with conventional transmitted light. Conclusion We have applied a design-unbiased method for quantitative evaluation of cartilage repair, and we propose this algorithm as a natural supplement to existing descriptive semiquantitative scoring systems. We also propose that polarized light is effective for discrimination between hyaline cartilage and fibrocartilage. PMID:26069715

A Stereological Method for the Quantitative Evaluation of Cartilage Repair Tissue.

PubMed

Foldager, Casper Bindzus; Nyengaard, Jens Randel; Lind, Martin; Spector, Myron

2015-04-01

To implement stereological principles to develop an easy applicable algorithm for unbiased and quantitative evaluation of cartilage repair. Design-unbiased sampling was performed by systematically sectioning the defect perpendicular to the joint surface in parallel planes providing 7 to 10 hematoxylin-eosin stained histological sections. Counting windows were systematically selected and converted into image files (40-50 per defect). The quantification was performed by two-step point counting: (1) calculation of defect volume and (2) quantitative analysis of tissue composition. Step 2 was performed by assigning each point to one of the following categories based on validated and easy distinguishable morphological characteristics: (1) hyaline cartilage (rounded cells in lacunae in hyaline matrix), (2) fibrocartilage (rounded cells in lacunae in fibrous matrix), (3) fibrous tissue (elongated cells in fibrous tissue), (4) bone, (5) scaffold material, and (6) others. The ability to discriminate between the tissue types was determined using conventional or polarized light microscopy, and the interobserver variability was evaluated. We describe the application of the stereological method. In the example, we assessed the defect repair tissue volume to be 4.4 mm(3) (CE = 0.01). The tissue fractions were subsequently evaluated. Polarized light illumination of the slides improved discrimination between hyaline cartilage and fibrocartilage and increased the interobserver agreement compared with conventional transmitted light. We have applied a design-unbiased method for quantitative evaluation of cartilage repair, and we propose this algorithm as a natural supplement to existing descriptive semiquantitative scoring systems. We also propose that polarized light is effective for discrimination between hyaline cartilage and fibrocartilage.

Metformin Induces Cell Cycle Arrest, Reduced Proliferation, Wound Healing Impairment In Vivo and Is Associated to Clinical Outcomes in Diabetic Foot Ulcer Patients.

PubMed

Ochoa-Gonzalez, Fatima; Cervantes-Villagrana, Alberto R; Fernandez-Ruiz, Julio C; Nava-Ramirez, Hilda S; Hernandez-Correa, Adriana C; Enciso-Moreno, Jose A; Castañeda-Delgado, Julio E

2016-01-01

Several epidemiological studies in diabetic patients have demonstrated a protective effect of metformin to the development of several types of cancer. The underlying mechanisms of such phenomenon is related to the effect of metformin on cell proliferation among which, mTOR, AMPK and other targets have been identified. However, little is known about the role that metformin treatment have on other cell types such as keratinocytes and whether exposure to metformin of these cells might have serious repercussions in wound healing delay and in the development of complications in diabetic patients with foot ulcers or in their exacerbation. HaCaT Cells were exposed to various concentrations of metformin and cell viability was evaluated by a Resazurin assay; Proliferation was also evaluated with a colony formation assay and with CFSE dilution assay by flow cytometry. Cell cycle was also evaluated by flow cytometry by PI staining. An animal model of wound healing was used to evaluate the effect of metformin in wound closure. Also, an analysis of patients receiving metformin treatment was performed to determine the effect of metformin treatment on the outcome and wound area. Statistical analysis was performed on SPSS v. 18 and GraphPad software v.5. Metformin treatment significantly reduces cell proliferation; colony formation and alterations of the cell cycle are observed also in the metformin treated cells, particularly in the S phase. There is a significant increase in the area of the wound of the metformin treated animals at different time points (P<0.05). There is also a significant increase in the size and wound area of the patients with diabetic foot ulcers at the time of hospitalization. A protective effect of metformin was observed for amputation, probably associated with the anti inflammatory effects reported of metformin. Metformin treatment reduces cell proliferation and reduces wound healing in an animal model and affects clinical outcomes in diabetic foot ulcer patients. Chronic use of this drug should be further investigated to provide evidence of their security in association with DFU.

DETECTION OF HUMAN ENTERIC VIRUSES IN STREAM WATER WITH RT-PCR AND CELL CULTURE

EPA Science Inventory

A multiplex RT-PCR method was used to measure virus occurrence at five stream water sites that span a range of hydroclimatic, water-quality, and land-use characteristics. The performance of the molecular method was evaluated in comparison to traditional cell culture and Escherich...

Lithium Iron Phosphate Cell Performance Evaluations for Lunar Extravehicular Activities

NASA Technical Reports Server (NTRS)

Reid, Concha

2007-01-01

Lithium-ion battery cells are being evaluated for their ability to provide primary power and energy storage for NASA s future Exploration missions. These missions include the Orion Crew Exploration Vehicle, the Ares Crew Launch Vehicle Upper Stage, Extravehicular Activities (EVA, the advanced space suit), the Lunar Surface Ascent Module (LSAM), and the Lunar Precursor and Robotic Program (LPRP), among others. Each of these missions will have different battery requirements. Some missions may require high specific energy and high energy density, while others may require high specific power, wide operating temperature ranges, or a combination of several of these attributes. EVA is one type of mission that presents particular challenges for today s existing power sources. The Portable Life Support System (PLSS) for the advanced Lunar surface suit will be carried on an astronaut s back during eight hour long sorties, requiring a lightweight power source. Lunar sorties are also expected to occur during varying environmental conditions, requiring a power source that can operate over a wide range of temperatures. Concepts for Lunar EVAs include a primary power source for the PLSS that can recharge rapidly. A power source that can charge quickly could enable a lighter weight system that can be recharged while an astronaut is taking a short break. Preliminary results of Al23 Ml 26650 lithium iron phosphate cell performance evaluations for an advanced Lunar surface space suit application are discussed in this paper. These cells exhibit excellent recharge rate capability, however, their specific energy and energy density is lower than typical lithium-ion cell chemistries. The cells were evaluated for their ability to provide primary power in a lightweight battery system while operating at multiple temperatures.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprik, Samuel; Kurtz, Jennifer M; Ainscough, Christopher D

In this presentation, the National Renewable Energy Laboratory presented aggregated analysis results on the performance of existing hydrogen stations, including performance, operation, utilization, maintenance, safety, hydrogen quality, and cost. The U.S. Department of Energy funds technology validation work at NREL through its National Fuel Cell Technology Evaluation Center (NFCTEC).

American Fuel Cell Bus Project Evaluation. Second Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eudy, Leslie; Post, Matthew

2015-09-01

This report presents results of the American Fuel Cell Bus (AFCB) Project, a demonstration of fuel cell electric buses operating in the Coachella Valley area of California. The prototype AFCB was developed as part of the Federal Transit Administration's (FTA's) National Fuel Cell Bus Program. Through the non-profit consortia CALSTART, a team led by SunLine Transit Agency and BAE Systems developed a new fuel cell electric bus for demonstration. SunLine added two more AFCBs to its fleet in 2014 and another in 2015. FTA and the AFCB project team are collaborating with the U.S. Department of Energy (DOE) and DOE'smore » National Renewable Energy Laboratory to evaluate the buses in revenue service. This report summarizes the performance results for the buses through June 2015.« less

The Evaluation of Triphenyl Phosphate as a Flame Retardant Additive to Improve the Safety of Lithium-Ion Battery Electrolytes

NASA Technical Reports Server (NTRS)

Smart, M. C.; Krause, F. C.; Hwang, C.; West, W. C.; Soler, J.; Prakash, G. K. S.; Ratnakumar, B. V.

2011-01-01

With the intent of improving the safety characteristics of lithium ion cells, electrolytes containing flame retardant additives have been investigated. A number of triphenyl phosphate-containing electrolytes were evaluated in both coin cells and experimental three electrode lithium-ion cells (containing reference electrodes). A number of chemistries were investigated, including MCMB carbon/LiNi(0.8)Co(0.2)O2 (NCO), graphite/LiNi(0.8)Co(0.15)Al(0.05)O2 (NCA), Li/Li(Li(0.17)Ni(0.25)Mn(0.58))O2, Li/LiNiMnCoO2 (NMC) and graphite/LiNiMnCoO2 (NMC), to study the effect that different electrolyte compositions have upon performance. A wide range of TPP-containing electrolytes were demonstrated to have good compatibility with the C/NCO, C/NCA, and Li/NMC systems, however, poor performance was initially observed with the high voltage C/NMC system. This necessitated the development of improved electrolytes with stabilizing additives, leading to formulations containing lithium bis(oxalato)borate (LiBOB) that displayed substantially improved performance.

Assessment of the predictive capacity of the optimized in vitro comet assay using HepG2 cells.

PubMed

Hong, Yoon-Hee; Jeon, Hye Lyun; Ko, Kyung Yuk; Kim, Joohwan; Yi, Jung-Sun; Ahn, Ilyoung; Kim, Tae Sung; Lee, Jong Kwon

2018-03-01

Evaluation of DNA damage is critical during the development of new drugs because it is closely associated with genotoxicity and carcinogenicity. The in vivo comet assay to assess DNA damage is globally harmonized as OECD TG 489. However, a comet test guideline that evaluates DNA damage without sacrificing animals does not yet exist. The goal of this study was to select an appropriate cell line for optimization of the in vitro comet assay to assess DNA damage. We then evaluated the predictivity of the in vitro comet assay using the selected cell line. In addition, the effect of adding S9 was evaluated using 12 test chemicals. For cell line selection, HepG2, Chinese hamster lung (CHL/IU), and TK6 cell lines were evaluated. We employed a method for the in vitro comet assay based on that for the in vivo comet assay. The most appropriate cell line was determined by% tail DNA increase after performing in vitro comet assays with 6 test chemicals. The predictivity of the in vitro comet assay using the selected cell line was measured with 10 test chemicals (8 genotoxins and 2 non-genotoxic chemicals). The HepG2 cell line was found to be the most appropriate, and in vitro comet assays using HepG2 cells exhibited a high accuracy of 90% (9/10). This study suggests that HepG2 is an optimal cell line for the in vitro comet assay to assess DNA damage. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessment and comparison of 100-MW coal gasification phosphoric acid fuel cell power plants

NASA Technical Reports Server (NTRS)

Lu, Cheng-Yi

1988-01-01

One of the advantages of fuel cell (FC) power plants is fuel versatility. With changes only in the fuel processor, the power plant will be able to accept a variety of fuels. This study was performed to design process diagrams, evaluate performance, and to estimate cost of 100 MW coal gasifier (CG)/phosphoric acid fuel cell (PAFC) power plant systems utilizing coal, which is the largest single potential source of alternate hydrocarbon liquids and gases in the United States, as the fuel. Results of this study will identify the most promising integrated CG/PAFC design and its near-optimal operating conditions. The comparison is based on the performance and cost of electricity which is calculated under consistent financial assumptions.

Battery Separator Characterization and Evaluation Procedures for NASA's Advanced Lithium-Ion Batteries

NASA Technical Reports Server (NTRS)

Baldwin, Richard S.; Bennet, William R.; Wong, Eunice K.; Lewton, MaryBeth R.; Harris, Megan K.

2010-01-01

To address the future performance and safety requirements for the electrical energy storage technologies that will enhance and enable future NASA manned aerospace missions, advanced rechargeable, lithium-ion battery technology development is being pursued within the scope of the NASA Exploration Technology Development Program s (ETDP's) Energy Storage Project. A critical cell-level component of a lithium-ion battery which significantly impacts both overall electrochemical performance and safety is the porous separator that is sandwiched between the two active cell electrodes. To support the selection of the optimal cell separator material(s) for the advanced battery technology and chemistries under development, laboratory characterization and screening procedures were established to assess and compare separator material-level attributes and associated separator performance characteristics.

Evaluation of the performance of a point-of-care method for total and differential white blood cell count in clozapine users.

PubMed

Bui, H N; Bogers, J P A M; Cohen, D; Njo, T; Herruer, M H

2016-12-01

We evaluated the performance of the HemoCue WBC DIFF, a point-of-care device for total and differential white cell count, primarily to test its suitability for the mandatory white blood cell monitoring in clozapine use. Leukocyte count and 5-part differentiation was performed by the point-of-care device and by routine laboratory method in venous EDTA-blood samples from 20 clozapine users, 20 neutropenic patients, and 20 healthy volunteers. From the volunteers, also a capillary sample was drawn. Intra-assay reproducibility and drop-to-drop variation were tested. The correlation between both methods in venous samples was r > 0.95 for leukocyte, neutrophil, and lymphocyte counts. The correlation between point-of-care (capillary sample) and routine (venous sample) methods for these cells was 0.772; 0.817 and 0.798, respectively. Only for leukocyte and neutrophil counts, the intra-assay reproducibility was sufficient. The point-of-care device can be used to screen for leukocyte and neutrophil counts. Because of the relatively high measurement uncertainty and poor correlation with venous samples, we recommend to repeat the measurement with a venous sample if cell counts are in the lower reference range. In case of clozapine therapy, neutropenia can probably be excluded if high neutrophil counts are found and patients can continue their therapy. © 2016 John Wiley & Sons Ltd.

Development and testing of a high cycle life 30 A-h sealed AgO-Zn battery

NASA Technical Reports Server (NTRS)

Bogner, R. S.

1972-01-01

A two-phase program was initiated to investigate design parameters and technology to develop an improved AgO-Zn battery. The basic performance goal was 100 charge/discharge cycles (22 h/2 h) at 50 percent depth of discharge following a six-month period of charged stand at room temperature. Phase 1, cell evaluation, involved testing 70 cells in five-cell groups. The major design variables were active material ratios, electrolyte concentrations, separator systems, and negative plate shape. Phase 1 testing showed that cycle life could be improved 10 percent to 20 percent by using greater ratios of zinc to silver oxide and higher electrolyte concentrations. Wedge-shaped negatives increased cycle life by nearly 100 percent. Phase 2 battery evaluation, which was initiated before the Phase 1 results were known completely, involved evaluation of six designs as 19-cell batteries. Only one battery exceeded 100 cycles following nine months charged stand.

Ebselen Preserves Tissue-Engineered Cell Sheets and their Stem Cells in Hypothermic Conditions

PubMed Central

Katori, Ryosuke; Hayashi, Ryuhei; Kobayashi, Yuki; Kobayashi, Eiji; Nishida, Kohji

2016-01-01

Clinical trials have been performed using autologous tissue-engineered epithelial cell sheets for corneal regenerative medicine. To improve stem cell-based therapy for convenient clinical practice, new techniques are required for preserving reconstructed tissues and their stem/progenitor cells until they are ready for use. In the present study, we screened potential preservative agents and developed a novel medium for preserving the cell sheets and their stem/progenitor cells; the effects were evaluated with a luciferase-based viability assay. Nrf2 activators, specifically ebselen, could maintain high ATP levels during preservation. Ebselen also showed a strong influence on maintenance of the viability, morphology, and stem cell function of the cell sheets preserved under hypothermia by protecting them from reactive oxygen species-induced damage. Furthermore, ebselen drastically improved the preservation performance of human cornea tissues and their stem cells. Therefore, ebselen shows good potential as a useful preservation agent in regenerative medicine as well as in cornea transplantation. PMID:27966584

Ebselen Preserves Tissue-Engineered Cell Sheets and their Stem Cells in Hypothermic Conditions.

PubMed

Katori, Ryosuke; Hayashi, Ryuhei; Kobayashi, Yuki; Kobayashi, Eiji; Nishida, Kohji

2016-12-14

Clinical trials have been performed using autologous tissue-engineered epithelial cell sheets for corneal regenerative medicine. To improve stem cell-based therapy for convenient clinical practice, new techniques are required for preserving reconstructed tissues and their stem/progenitor cells until they are ready for use. In the present study, we screened potential preservative agents and developed a novel medium for preserving the cell sheets and their stem/progenitor cells; the effects were evaluated with a luciferase-based viability assay. Nrf2 activators, specifically ebselen, could maintain high ATP levels during preservation. Ebselen also showed a strong influence on maintenance of the viability, morphology, and stem cell function of the cell sheets preserved under hypothermia by protecting them from reactive oxygen species-induced damage. Furthermore, ebselen drastically improved the preservation performance of human cornea tissues and their stem cells. Therefore, ebselen shows good potential as a useful preservation agent in regenerative medicine as well as in cornea transplantation.

Coal-Based Fuel-Cell Powerplants

NASA Technical Reports Server (NTRS)

Ferral, J. F.; Pappano, A. W.; Jennings, C. N.

1986-01-01

Report assesses advanced technologyy design alternatives for integrated coal-gasifier/fuel-cell powerplants. Various gasifier, cleanup, and fuelcell options evaluated. Evaluation includes adjustments to assumed performances and costs of proposed technologies where required. Analysis identifies uncertainties remaining in designs and most promising alternatives and research and development required to develop these technologies. Bulk of report summary and detailed analysis of six major conceptual designs and variations of each. All designs for plant that uses Illinois No. 6 coal and produces 675 MW of net power.

Tailored Core Shell Cathode Powders for Solid Oxide Fuel Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swartz, Scott

2015-03-23

In this Phase I SBIR project, a “core-shell” composite cathode approach was evaluated for improving SOFC performance and reducing degradation of lanthanum strontium cobalt ferrite (LSCF) cathode materials, following previous successful demonstrations of infiltration approaches for achieving the same goals. The intent was to establish core-shell cathode powders that enabled high performance to be obtained with “drop-in” process capability for SOFC manufacturing (i.e., rather than adding an infiltration step to the SOFC manufacturing process). Milling, precipitation and hetero-coagulation methods were evaluated for making core-shell composite cathode powders comprised of coarse LSCF “core” particles and nanoscale “shell” particles of lanthanum strontiummore » manganite (LSM) or praseodymium strontium manganite (PSM). Precipitation and hetero-coagulation methods were successful for obtaining the targeted core-shell morphology, although perfect coverage of the LSCF core particles by the LSM and PSM particles was not obtained. Electrochemical characterization of core-shell cathode powders and conventional (baseline) cathode powders was performed via electrochemical impedance spectroscopy (EIS) half-cell measurements and single-cell SOFC testing. Reliable EIS testing methods were established, which enabled comparative area-specific resistance measurements to be obtained. A single-cell SOFC testing approach also was established that enabled cathode resistance to be separated from overall cell resistance, and for cathode degradation to be separated from overall cell degradation. The results of these EIS and SOFC tests conclusively determined that the core-shell cathode powders resulted in significant lowering of performance, compared to the baseline cathodes. Based on the results of this project, it was concluded that the core-shell cathode approach did not warrant further investigation.« less

Antitumoural effect of Synadenium grantii Hook f. (Euphorbiaceae) latex.

PubMed

de Oliveira, Thais Latansio; Munhoz, Antônio Carlos Mattar; Lemes, Bruna Mikulis; Minozzo, Bruno Rodrigo; Nepel, Angelita; Barison, Andersson; Fávero, Giovani Marino; Campagnoli, Eduardo Bauml; Beltrame, Flávio Luís

2013-10-28

Synadenium grantii Hook f. has traditionally been used to treat various neoplastic diseases in southern Brazil. Evaluation of the antitumoural potential of Synadenium grantii latex against B16F10 melanoma cell line using in vitro and in vivo models, as well as a phytochemical study of the latex. The in vitro antitumoural activity was performed using MTT and trypan blue assays with different latex concentrations (1.7 µg-7.0 µg/well and 1.22 mg-4.88 mg/well). Flow cytometry was used to determine the progression of the cell cycle. The in vivo activity was performed by subcutaneously injecting melanoma cells in the dorsum of C57BL6 mice, followed by treating the mice with a popular form of use of the latex (garrafada) administered orally. After sacrificing the animals, histological analysis of the organs was performed by hematoxylin-eosin staining. The phytochemical study of the latex was performed by NMR and chromatographic procedures and the extracts and isolated substances were evaluated by IR, 1D and 2D NMR analysis. The Synadenium grantii latex exhibited decreased cell viability of the melanoma line in a concentration and time-dependent manner, and also cell cycle arrest in the S-G2/M phase. The latex caused a 40% reduction in the volume of tumours of the mice with melanomas. Histological examination of the organs of these animals showed no differences between groups. The phytochemical investigation resulted in the isolation and identification of triterpene euphol and the steroid citrostadienol, which were tested against the strain of melanoma. Euphol showed no antitumoural activity, while the steroid citrostadienol showed reduced cytotoxic activity. The Synadenium grantii latex presented in vitro and in vivo cytotoxic effects with antitumoural activity against B16F10 melanoma cells. © 2013 Elsevier Ireland Ltd. All rights reserved.

A new fluorescent imaging procedure in vivo for evaluation of the retinal microcirculation in rats.

PubMed

Kimura, H; Kiryu, J; Nishiwaki, H; Ogura, Y

1995-03-01

We investigated a new method for in vivo evaluation of the retinal microcirculation in rats using a cell-permeant fluorescent dye, acridine orange (AO), which stains cell nuclei and cytoplasm, and a scanning laser ophthalmoscope (SLO). AO, which binds and interacts with DNA and RNA, and thus stains cell nuclei and cytoplasm, was administered intravenously to rats. Fluorescein angiography was performed after administration of the AO, and fundus images were recorded on S-VHS videotape by means of an SLO. Argon laser was used as an exciter of the dye. The retinal vessels were stained with the dye, rendering the retinal microvasculature clearly visible. Cell nuclei and vessel walls were observed as greater fluorescence and lesser fluorescence, respectively. Leukocytes were also observed as highly fluorescent dots moving through the vessels. The results suggest that SLO visualization of AO uptake by cells may be a useful procedure for the evaluation of retinal microcirculation in vivo in rats.

Spraylon fluorocarbon encapsulation for silicon solar cell arrays

NASA Technical Reports Server (NTRS)

1977-01-01

A development program was performed for evaluating, modifying, and optimizing the Lockheed formulated liquid transparent filmforming Spraylon fluorocarbon protective coating for silicon solar cells and modules. The program objectives were designed to meet the requirements of the low-cost automated solar cell array fabrication process. As part of the study, a computer program was used to establish the limits of the safe working stress in the coated silicon solar cell array system under severe thermal shock.

Deficiencies in school readiness skills of children with sickle cell anemia: a preliminary report.

PubMed

Chua-Lim, C; Moore, R B; McCleary, G; Shah, A; Mankad, V N

1993-04-01

Patients with sickle cell anemia often express myriad clinical signs and symptoms that affect their life-style and academic performance. Certain psychoeducational and psychosocial factors have been shown to influence the academic achievement of older patients with sickle cell anemia. However, studies evaluating the school readiness skills of younger children have not been published. To determine whether sickle cell anemia delays preschool development in children aged 4 to 6 years, we studied 10 affected children and 10 normal subjects matched for age, sex, and race. School readiness was evaluated by the Pediatric Examination of Educational Readiness (PEER), which assess a child's performance in areas of developmental attainment such as visual input, verbal output, and short-term memory. The presence of associated movements (minor neurologic signs) and other areas of behavior such as selective attention, activity level, adaptive behavior, and processing efficiency are also observed. The children with sickle cell anemia scored significantly lower than their normal counterparts in several parameters of the PEER. The McCarthy Scales of Children's Abilities, a standardized psychometric test, showed that these children with sickle cell anemia were within the normal range of intelligence. Magnetic resonance imaging done on three children with sickle cell anemia who scored lowest on the PEER revealed no cerebrovascular infarcts. These preliminary studies demonstrate significant differences in school readiness skills between children with sickle cell anemia and normal subjects.

SiRNA knockdown of the DEK nuclear protein mRNA enhances apoptosis and chemosensitivity of canine transitional cell carcinoma cells.

PubMed

Yamazaki, Hiroki; Iwano, Tomomi; Otsuka, Saori; Kagawa, Yumiko; Hoshino, Yuki; Hosoya, Kenji; Okumura, Masahiro; Takagi, Satoshi

2015-04-01

Transitional cell carcinoma (TCC) in dogs is an aggressive malignant neoplasm, originating in the epithelium of the urinary bladder. The DEK nuclear protein is overexpressed in several types of human bladder cancer, where it is involved in chromatin reconstruction, gene transcription and apoptosis. Since DEK represents a potential therapeutic target for canine TCC, this study was designed to investigate DEK expression in canine TCC and to determine the effects of DEK mRNA silencing on TCC cells in vitro. The gene expression profiles of seven selected cancer-associated genes was assessed in four canine TCC cell lines and expression of DEK protein was evaluated in bladder tissue biopsies from healthy dogs and those affected with cystitis or TCC. After transfection of four canine TCC cell lines with DEK-specific or scrambled siRNA, annexin V staining was performed to evaluate apoptosis, and methylthiazole tetrazolium assays were performed to assess both cell viability and sensitivity to carboplatin. DEK mRNA expression was relatively high in canine TCC cells and expression of the DEK protein was significantly greater in TCC tumours compared with the other tissue samples. After transfection with DEK-specific siRNA, apoptosis, cell growth inhibition, and enhanced sensitivity to carboplatin were observed in all TCC cells assessed. These research findings suggest that DEK could be a potential therapeutic target for canine TCC. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analysis of long-time operation of micro-cogeneration unit with fuel cell

NASA Astrophysics Data System (ADS)

Patsch, Marek; Čaja, Alexander

2015-05-01

Micro-cogeneration is cogeneration with small performance, with maximal electric power up to 50 kWe. On the present, there are available small micro-cogeneration units with small electric performance, about 1 kWe, which are usable also in single family houses or flats. These micro-cogeneration units operate on principle of conventional combustion engine, Stirling engine, steam engine or fuel cell. Micro-cogeneration units with fuel cells are new progressive developing type of units for single family houses. Fuel cell is electrochemical device which by oxidation-reduction reaction turn directly chemical energy of fuel to electric power, secondary products are pure water and thermal energy. The aim of paper is measuring and evaluation of operation parameters of micro-cogeneration unit with fuel cell which uses natural gas as a fuel.

Endoscopic Ultrasound-guided Specimen Collection and Evaluation Techniques Affect Diagnostic Accuracy.

PubMed

Bang, Ji Young; Navaneethan, Udayakumar; Hasan, Muhammad K; Hawes, Robert; Varadarajulu, Shyam

2018-03-11

Outcomes of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) evaluation vary with technique, needles, and methods of specimen evaluation. We performed a direct comparison of diagnostic yields of EUS-FNA samples collected using different gauge needles (22- vs 25-gauge), with or without suction. We performed a randomized controlled study of 352 patients with suspected pancreatic masses, referred for EUS-FNA at a tertiary referral center. Patients were randomly assigned to 22-gauge needles with or without suction or 25-gauge needles with or without suction. Specimens were evaluated offsite by cell block and rapid onsite cytologic evaluation (ROSE). Final diagnoses were made based on histologic analyses or 12-month follow-up evaluations. The primary outcome was diagnostic adequacy of cell blocks. Secondary outcomes were operating characteristics of ROSE and EUS-FNA, number of passes required for accurate onsite diagnosis, and amount of blood in specimens. The final diagnoses were malignancy (81.5% of patients) and benign disease (17.0% of patients); 1.4% of patients were lost during follow up. Cell block, ROSE, and EUS-FNA led to diagnostic accuracies of 71.9%, 95.5%, and 96.6%, respectively. A 22-gauge needle with suction was associated with more passes for adequate onsite diagnosis (P = .003) and specimens contained more blood (P = .01). Diagnostic accuracy of specimens collected by transduodenal EUS-FNA was lower with 22-gauge needles with suction compared to other techniques (P = .004). In a randomized trial of patients undergoing EUS-FNA for pancreatic masses, samples collected with 22-gauge vs 25-gauge needles performed equally well for offsite specimen evaluation. Use of suction appears to increase number of passes needed and specimen bloodiness. Specimen collection techniques should be individualized based on method of evaluation. ClinicalTrials.gov no: NCT02424838. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Study on Topology Optimization Design, Manufacturability, and Performance Evaluation of Ti-6Al-4V Porous Structures Fabricated by Selective Laser Melting (SLM)

PubMed Central

Xu, Yangli; Zhang, Dongyun; Zhou, Yan; Wang, Weidong; Cao, Xuanyang

2017-01-01

The combination of topology optimization (TOP) and selective laser melting (SLM) provides the possibility of fabricating the complex, lightweight and high performance geometries overcoming the traditional manufacturing “bottleneck”. This paper evaluates the biomechanical properties of porous structures with porosity from 40% to 80% and unit cell size from 2 to 8 mm, which are designed by TOP and manufactured by SLM. During manufacturability exploration, three typical structures including spiral structure, arched bridge structure and structures with thin walls and small holes are abstracted and investigated, analyzing their manufacturing limits and forming reason. The property tests show that dynamic elastic modulus and compressive strength of porous structures decreases with increases of porosity (constant unit cell size) or unit cell size (constant porosity). Based on the Gibson-Ashby model, three failure models are proposed to describe their compressive behavior, and the structural parameter λ is used to evaluate the stability of the porous structure. Finally, a numerical model for the correlation between porous structural parameters (unit cell size and porosity) and elastic modulus is established, which provides a theoretical reference for matching the elastic modulus of human bones from different age, gender and skeletal sites during innovative medical implant design and manufacturing. PMID:28880229

Study on Topology Optimization Design, Manufacturability, and Performance Evaluation of Ti-6Al-4V Porous Structures Fabricated by Selective Laser Melting (SLM).

PubMed

Xu, Yangli; Zhang, Dongyun; Zhou, Yan; Wang, Weidong; Cao, Xuanyang

2017-09-07

The combination of topology optimization (TOP) and selective laser melting (SLM) provides the possibility of fabricating the complex, lightweight and high performance geometries overcoming the traditional manufacturing "bottleneck". This paper evaluates the biomechanical properties of porous structures with porosity from 40% to 80% and unit cell size from 2 to 8 mm, which are designed by TOP and manufactured by SLM. During manufacturability exploration, three typical structures including spiral structure, arched bridge structure and structures with thin walls and small holes are abstracted and investigated, analyzing their manufacturing limits and forming reason. The property tests show that dynamic elastic modulus and compressive strength of porous structures decreases with increases of porosity (constant unit cell size) or unit cell size (constant porosity). Based on the Gibson-Ashby model, three failure models are proposed to describe their compressive behavior, and the structural parameter λ is used to evaluate the stability of the porous structure. Finally, a numerical model for the correlation between porous structural parameters (unit cell size and porosity) and elastic modulus is established, which provides a theoretical reference for matching the elastic modulus of human bones from different age, gender and skeletal sites during innovative medical implant design and manufacturing.

Renal Cell Carcinoma: Comparison of RENAL Nephrometry and PADUA Scores with Maximum Tumor Diameter for Prediction of Local Recurrence after Thermal Ablation.

PubMed

Maxwell, Aaron W P; Baird, Grayson L; Iannuccilli, Jason D; Mayo-Smith, William W; Dupuy, Damian E

2017-05-01

Purpose To evaluate the performance of the radius, exophytic or endophytic, nearness to collecting system or sinus, anterior or posterior, and location relative to polar lines (RENAL) nephrometry and preoperative aspects and dimensions used for anatomic classification (PADUA) scoring systems and other tumor biometrics for prediction of local tumor recurrence in patients with renal cell carcinoma after thermal ablation. Materials and Methods This HIPAA-compliant study was performed with a waiver of informed consent after institutional review board approval was obtained. A retrospective evaluation of 207 consecutive patients (131 men, 76 women; mean age, 71.9 years ± 10.9) with 217 biopsy-proven renal cell carcinoma tumors treated with thermal ablation was conducted. Serial postablation computed tomography (CT) or magnetic resonance (MR) imaging was used to evaluate for local tumor recurrence. For each tumor, RENAL nephrometry and PADUA scores were calculated by using imaging-derived tumor morphologic data. Several additional tumor biometrics and combinations thereof were also measured, including maximum tumor diameter. The Harrell C index and hazard regression techniques were used to quantify associations with local tumor recurrence. Results The RENAL (hazard ratio, 1.43; P = .003) and PADUA (hazard ratio, 1.80; P < .0001) scores were found to be significantly associated with recurrence when regression techniques were used but demonstrated only poor to fair discrimination according to Harrell C index results (C, 0.68 and 0.75, respectively). Maximum tumor diameter showed the highest discriminatory strength of any individual variable evaluated (C, 0.81) and was also significantly predictive when regression techniques were used (hazard ratio, 2.98; P < .0001). For every 1-cm increase in diameter, the estimated rate of recurrence risk increased by 198%. Conclusion Maximum tumor diameter demonstrates superior performance relative to existing tumor scoring systems and other evaluated biometrics for prediction of local tumor recurrence after renal cell carcinoma ablation. © RSNA, 2016.

Serum LDL cholesterol concentration and lipoprotein electrophoresis pattern in patients with small cell lung cancer.

PubMed

Siemianowicz, K; Gminski, J; Stajszczyk, M; Wojakowski, W; Goss, M; Machalski, M; Telega, A; Brulinski, K; Magiera-Molendowska, H

2000-01-01

Epidemiological studies show that people with low level of total cholesterol have a greater risk of death due to cancer, predominantly lung cancer. The aim of our study was to evaluate serum level of LDL cholesterol and lipoprotein electrophoresis pattern in patients with small cell lung cancer and their dependence on clinical stage of the neoplasm. The studied group consisted of 34 patients with newly diagnosed small cell lung cancer and 39 healthy controls. Fasting level of LDL cholesterol was analyzed and lipoprotein electrophoresis was performed. There were no statistically significant differences of evaluated serum lipid parameters between lung cancer patients and controls, and between the clinical stages of small cell lung cancer.

Interlaboratory Evaluation of in Vitro Cytotoxicity and Inflammatory Responses to Engineered Nanomaterials: The NIEHS Nano GO Consortium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xia, Tian; Hamilton, Raymond F.; Bonner, James C.

2013-06-01

Background: Differences in interlaboratory research protocols contribute to the conflicting data in the literature regarding engineered nanomaterial (ENM) bioactivity. Objectives: Grantees of a National Institute of Health Sciences (NIEHS)-funded consortium program performed two phases of in vitro testing with selected ENMs in an effort to identify and minimize sources of variability. Methods: Consortium program participants (CPPs) conducted ENM bioactivity evaluations on zinc oxide (ZnO), three forms of titanium dioxide (TiO2), and three forms of multiwalled carbon nanotubes (MWCNTs). In addition, CPPs performed bioassays using three mammalian cell lines (BEAS-2B, RLE-6TN, and THP-1) selected in order to cover two different speciesmore » (rat and human), two different lung epithelial cells (alveolar type II and bronchial epithelial cells), and two different cell types (epithelial cells and macrophages). CPPs also measured cytotoxicity in all cell types while measuring inflammasome activation [interleukin-1β (IL-1β) release] using only THP-1 cells. Results: The overall in vitro toxicity profiles of ENM were as follows: ZnO was cytotoxic to all cell types at ≥ 50 μ g/mL, but did not induce IL-1β. TiO2 was not cytotoxic except for the nanobelt form, which was cytotoxic and induced significant IL-1β production in THP-1 cells. MWCNTs did not produce cytotoxicity, but stimulated lower levels of IL-1β production in THP-1 cells, with the original MWCNT producing the most IL-1β. Conclusions: The results provide justification for the inclusion of mechanism-linked bioactivity assays along with traditional cytotoxicity assays for in vitro screening. In addition, the results suggest that conducting studies with multiple relevant cell types to avoid false-negative outcomes is critical for accurate evaluation of ENM bioactivity.« less

Performance evaluation of Abbott CELL-DYN Ruby for routine use.

PubMed

Lehto, T; Hedberg, P

2008-10-01

CELL-DYN Ruby is a new automated hematology analyzer suitable for routine use in small laboratories and as a back-up or emergency analyzer in medium- to high-volume laboratories. The analyzer was evaluated by comparing the results from the CELL-DYN((R)) Ruby with the results obtained from CELL-DYN Sapphire . Precision, linearity, and carryover between patient samples were also assessed. Precision was good at all levels for the routine cell blood count (CBC) parameters, CV% being or= 0.98) with CELL-DYN Sapphire for the CBC parameters. For the absolute reticulocyte count, R(2) was 0.82. In the white blood cell (WBC) differentials, the between-days precision was good for all parameters (CV%: or= 0.97), and the correlation coefficient for absolute monocyte count and monocyte percentage were 0.91 and 0.87, respectively. For absolute basophil count and basophil percentage the correlations were weaker (R(2) = 0.46 and 0.34, respectively). Carryover was minimal for all the parameters studied. The linearities of WBC, red blood cell, PLTs, and hemoglobin were acceptable within the tested ranges. In conclusion, the results of the evaluation showed the performance of CELL-DYN Ruby to be good.

[Phenotype-based primary screening for drugs promoting neuronal subtype differentiation in embryonic stem cells with light microscope].

PubMed

Gao, Yi-ning; Wang, Dan-ying; Pan, Zong-fu; Mei, Yu-qin; Wang, Zhi-qiang; Zhu, Dan-yan; Lou, Yi-jia

2012-07-01

To set up a platform for phenotype-based primary screening of drug candidates promoting neuronal subtype differentiation in embryonic stem cells (ES) with light microscope. Hanging drop culture 4-/4+ method was employed to harvest the cells around embryoid body (EB) at differentiation endpoint. Morphological evaluation for neuron-like cells was performed with light microscope. Axons for more than three times of the length of the cell body were considered as neuron-like cells. The compound(s) that promote neuron-like cells was further evaluated. Icariin (ICA, 10(-6)mol/L) and Isobavachin (IBA, 10(-7)mol/L) were selected to screen the differentiation-promoting activity on ES cells. Immunofluorescence staining with specific antibodies (ChAT, GABA) was used to evaluate the neuron subtypes. The cells treated with IBA showed neuron-like phenotype, but the cells treated with ICA did not exhibit the morphological changes. ES cells treated with IBA was further confirmed to be cholinergic and GABAergic neurons. Phenotypic screening with light microscope for molecules promoting neuronal differentiation is an effective method with advantages of less labor and material consuming and time saving, and false-positive results derived from immunofluorescence can be avoided. The method confirms that IBA is able to facilitate ES cells differentiating into neuronal cells, including cholinergic neurons and GABAergic neurons.

Dynamic modeling, experimental evaluation, optimal design and control of integrated fuel cell system and hybrid energy systems for building demands

NASA Astrophysics Data System (ADS)

Nguyen, Gia Luong Huu

Fuel cells can produce electricity with high efficiency, low pollutants, and low noise. With the advent of fuel cell technologies, fuel cell systems have since been demonstrated as reliable power generators with power outputs from a few watts to a few megawatts. With proper equipment, fuel cell systems can produce heating and cooling, thus increased its overall efficiency. To increase the acceptance from electrical utilities and building owners, fuel cell systems must operate more dynamically and integrate well with renewable energy resources. This research studies the dynamic performance of fuel cells and the integration of fuel cells with other equipment in three levels: (i) the fuel cell stack operating on hydrogen and reformate gases, (ii) the fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit, and (iii) the hybrid energy system consisting of photovoltaic panels, fuel cell system, and energy storage. In the first part, this research studied the steady-state and dynamic performance of a high temperature PEM fuel cell stack. Collaborators at Aalborg University (Aalborg, Denmark) conducted experiments on a high temperature PEM fuel cell short stack at steady-state and transients. Along with the experimental activities, this research developed a first-principles dynamic model of a fuel cell stack. The dynamic model developed in this research was compared to the experimental results when operating on different reformate concentrations. Finally, the dynamic performance of the fuel cell stack for a rapid increase and rapid decrease in power was evaluated. The dynamic model well predicted the performance of the well-performing cells in the experimental fuel cell stack. The second part of the research studied the dynamic response of a high temperature PEM fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit with high thermal integration. After verifying the model performance with the obtained experimental data, the research studied the control of airflow to regulate the temperature of reactors within the fuel processor. The dynamic model provided a platform to test the dynamic response for different control gains. With sufficient sensing and appropriate control, a rapid response to maintain the temperature of the reactor despite an increase in power was possible. The third part of the research studied the use of a fuel cell in conjunction with photovoltaic panels, and energy storage to provide electricity for buildings. This research developed an optimization framework to determine the size of each device in the hybrid energy system to satisfy the electrical demands of buildings and yield the lowest cost. The advantage of having the fuel cell with photovoltaic and energy storage was the ability to operate the fuel cell at baseload at night, thus reducing the need for large battery systems to shift the solar power produced in the day to the night. In addition, the dispatchability of the fuel cell provided an extra degree of freedom necessary for unforeseen disturbances. An operation framework based on model predictive control showed that the method is suitable for optimizing the dispatch of the hybrid energy system.

Performance, size, mass, and cost estimates for projected 1kW EOL Si, InP, and GaAs arrays

NASA Technical Reports Server (NTRS)

Slifer, Luther W., Jr.

1991-01-01

One method of evaluating the potential of emerging solar cell and array technologies is to compare their projected capabilities in space flight applications to those of established Si solar cells and arrays. Such an application-oriented comparison provides an integrated view of the elemental comparisons of efficiency, radiation resistance, temperature sensitivity, size, mass, and cost in combination. In addition, the assumptions necessary to make the comparisons provide insights helpful toward determining necessary areas of development or evaluation. Finally, as developments and evaluations progress, the results can be used in more precisely defining the overall potential of the new technologies in comparison to existing technologies. The projected capabilities of Si, InP, and GaAs cells and arrays are compared.

Thermo-electrochemical evaluation of lithium-ion batteries for space applications

NASA Astrophysics Data System (ADS)

Walker, W.; Yayathi, S.; Shaw, J.; Ardebili, H.

2015-12-01

Advanced energy storage and power management systems designed through rigorous materials selection, testing and analysis processes are essential to ensuring mission longevity and success for space exploration applications. Comprehensive testing of Boston Power Swing 5300 lithium-ion (Li-ion) cells utilized by the National Aeronautics and Space Administration (NASA) to power humanoid robot Robonaut 2 (R2) is conducted to support the development of a test-correlated Thermal Desktop (TD) Systems Improved Numerical Differencing Analyzer (SINDA) (TD-S) model for evaluation of power system thermal performance. Temperature, current, working voltage and open circuit voltage measurements are taken during nominal charge-discharge operations to provide necessary characterization of the Swing 5300 cells for TD-S model correlation. Building from test data, embedded FORTRAN statements directly simulate Ohmic heat generation of the cells during charge-discharge as a function of surrounding temperature, local cell temperature and state of charge. The unique capability gained by using TD-S is demonstrated by simulating R2 battery thermal performance in example orbital environments for hypothetical extra-vehicular activities (EVA) exterior to a small satellite. Results provide necessary demonstration of this TD-S technique for thermo-electrochemical analysis of Li-ion cells operating in space environments.

Short-term application of dexamethasone on stem cells derived from human gingiva reduces the expression of RUNX2 and β-catenin.

PubMed

Kim, Bo-Bae; Kim, Minji; Park, Yun-Hee; Ko, Youngkyung; Park, Jun-Beom

2017-06-01

Objective Next-generation sequencing was performed to evaluate the effects of short-term application of dexamethasone on human gingiva-derived mesenchymal stem cells. Methods Human gingiva-derived stem cells were treated with a final concentration of 10 -7  M dexamethasone and the same concentration of vehicle control. This was followed by mRNA sequencing and data analysis, gene ontology and pathway analysis, quantitative real-time polymerase chain reaction of mRNA, and western blot analysis of RUNX2 and β-catenin. Results In total, 26,364 mRNAs were differentially expressed. Comparison of the results of dexamethasone versus control at 2 hours revealed that 7 mRNAs were upregulated and 25 mRNAs were downregulated. The application of dexamethasone reduced the expression of RUNX2 and β-catenin in human gingiva-derived mesenchymal stem cells. Conclusion The effects of dexamethasone on stem cells were evaluated with mRNA sequencing, and validation of the expression was performed with qualitative real-time polymerase chain reaction and western blot analysis. The results of this study can provide new insights into the role of mRNA sequencing in maxillofacial areas.

A novel differential electrochemical mass spectrometry method to determine the product distribution from parasitic Methanol oxidation reaction on oxygen reduction reaction catalysts

NASA Astrophysics Data System (ADS)

Jurzinsky, Tilman; Kurzhals, Philipp; Cremers, Carsten

2018-06-01

The oxygen reduction reaction is in research focus since several decades due to its importance for the overall fuel cell performance. In direct methanol fuel cells, the crossover of methanol and its subsequent parasitic oxidation are main issues when it comes to preventing fuel cell performance losses. In this work, we present a novel differential electrochemical mass spectrometry method to evaluate oxygen reduction reaction catalysts on their tolerance to methanol being present at the cathode. Besides this, the setup allows to measure under more realistic fuel cell conditions than typical rotating disc electrode measurements, because the oxygen reduction reaction is evaluated in gaseous phase and a gas diffusion electrode is used as working electrode. Due to the new method, it was possible to investigate the oxygen reduction reaction on two commonly used catalysts (Pt/C and Pt3Co/C) in absence and presence of methanol. It was found, that Pt3Co/C is less prone to parasitic current losses due to methanol oxidation reaction. By connecting a mass spectrometer to the electrochemical cell, the new method allows to determine the products formed on the catalysts due to parasitic methanol electrooxidation.

Locality of Area Coverage on Digital Acoustic Communication in Air using Differential Phase Shift Keying

NASA Astrophysics Data System (ADS)

Mizutani, Keiichi; Ebihara, Tadashi; Wakatsuki, Naoto; Mizutani, Koichi

2009-07-01

We experimentally evaluate the locality of digital acoustic communication in air. Digital acoustic communication in air is suitable for a small cell system, because acoustic waves have a short propagation distance in air. In this study, optimal cell size is experimentally evaluated. Each base station (BS) transmits different commands. In our experiment, differential phase shift keying (DPSK), especially binary DPSK (DBPSK), is adopted as a modulation and demodulation scheme. The evaluated system consists of a personal computer (PC), a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), a loud speaker (SP), a microphone (MIC), and transceiver software. All experiments are performed in an anechoic room. The cell size of the transmitter can be limited under low signal-to-noise ratio (SNR) condition. If another transmitter works, cell size is limited by the effect of the interference from that transmitter. The cell size-to-distance ratio of transmitter A to transmitter B is 37.5%, if cell edge bit-error-rate (BER) is taken as 10-3.

Adenovirus expressing IFN-λ (Ad/hIFN-λ) produced anti-tumor effects through inducing apoptosis in human tongue squamous cell carcinoma cell.

PubMed

Song, Bing; Yang, Yong; Wang, Yan-Li; Fan, Xiao-Hui; Huang, Yu-Mei; Ci, Hao-Su; Zuo, Jin-Hua

2015-01-01

To investigate the potential therapeutic effects of adenovirus expressing IFN-λ1 and IFN-λ2 (Ad/hIFN-λ) in treating squamous cell carcinoma of the oral tongue (SCCOT) and to explore the underlying mechanisms. Two SCCOT cell lines HSC-3 and Tca8113 were adopted as study objects. Cell Counting Kit-8 (CCK-8) cell proliferation and viability assay was performed to evaluate the antiproliferative effects of Ad/hIFN-λ and IFN-λ treatments at different dosages. Flow cytometry (FCM) was performed to investigate the apoptosis rate induced by Ad/hIFN-λ. In vivo study was performed through evaluating tumorigenicity and tumor volume on BALB/c nu/nu mice inoculated with HSC-3 cells with or without infection of Ad/hIFN-λ. qPCR was used to screen important apoptosis related genes expression and western blot (WB) was performed to verify the results. WB was also used to test the phosphorylation of STATs protein in the JAK/STAT signaling pathways. Our results indicated an obvious antiproliferative effect of Ad/hIFN-λ in vitro on infected HSC-3 and Tca8113 cells. The antiproliferative effects started to appear at 48 h (day 2) after infection. IFN-λs alone treating HSC-3 and Tca8113 cells also showed a dose-dependent inhibitory manner. Though the antiproliferative effects did not show on 24 h (day 1), early apoptosis rate already increased significantly in cells infected with Ad/hIFN-λ (P<0.05) detected by FCM. The underlying mechanisms of antiproliferative activity rely on the IFN-λ signaling by phosphorylation of STATs protein. Expression of Bax, Bcl-2 and Caspase-3 were promoted by Ad/hIFN-λ leading to higher apoptosis rate. Upper stream of p21 and Rb dephosphorylation explained the Caspase-3 activation. Animal study showed that HSC-3 cells infected with Ad/hIFN-λ significantly promoted the survival rate and decreased mean tumor volume comparing to HSC-3 cells group. Ad/hIFN-λ injection had obvious antiproliferative effects on HSC-3 and Tca8113 cells. Ad/hIFN-λ induced apoptosis in SCCOT cells through increasing Bcl-2, Bax and Caspase-3 expression. Ad/hIFN-λ is a potential therapeutic strategy in treating oral tongue carcinoma.

Photovoltaic performance of textured silicon solar cells with MAPbBr3 perovskite nanophosphors to induce luminescent down-shifting

NASA Astrophysics Data System (ADS)

Ho, Wen-Jeng; Li, Guan-Yi; Liu, Jheng-Jie; Lin, Zong-Xian; You, Bang-Jin; Ho, Chun-Hung

2018-04-01

This study employed a two-step multi-cycle spin-coating method for the application of MAPbBr3 perovskite nanophosphors on textured silicon solar cells with the aim of enhancing photovoltaic performance through luminescent down-shifting (LDS). The surface morphology and dimensions of the MAPbBr3 perovskite nanophosphors were examined using scanning electron microscopy in conjunction with ImageJ software. The LDS effects of the nanophosphors were revealed by measuring photo-luminance, optical reflectance, and external quantum efficiency. The photovoltaic performance of cells with and without MAPbBr3 perovskite nanophosphors was evaluated according to photovoltaic current density-voltage (J-V) under AM 1.5 G solar illumination. Compared to uncoated cells, two-layer and one-layer coatings of MAPbBr3 perovskite nanophosphors were shown to enhance conversion efficiency by 4.56% and 3.38%, respectively.

An Objective Comparison of Cell Tracking Algorithms

PubMed Central

Ulman, Vladimír; Maška, Martin; Magnusson, Klas E. G.; Ronneberger, Olaf; Haubold, Carsten; Harder, Nathalie; Matula, Pavel; Matula, Petr; Svoboda, David; Radojevic, Miroslav; Smal, Ihor; Rohr, Karl; Jaldén, Joakim; Blau, Helen M.; Dzyubachyk, Oleh; Lelieveldt, Boudewijn; Xiao, Pengdong; Li, Yuexiang; Cho, Siu-Yeung; Dufour, Alexandre C.; Olivo-Marin, Jean-Christophe; Reyes-Aldasoro, Constantino C.; Solis-Lemus, Jose A.; Bensch, Robert; Brox, Thomas; Stegmaier, Johannes; Mikut, Ralf; Wolf, Steffen; Hamprecht, Fred. A.; Esteves, Tiago; Quelhas, Pedro; Demirel, Ömer; Malmström, Lars; Jug, Florian; Tomancak, Pavel; Meijering, Erik; Muñoz-Barrutia, Arrate; Kozubek, Michal; Ortiz-de-Solorzano, Carlos

2017-01-01

We present a combined report on the results of three editions of the Cell Tracking Challenge, an ongoing initiative aimed at promoting the development and objective evaluation of cell tracking algorithms. With twenty-one participating algorithms and a data repository consisting of thirteen datasets of various microscopy modalities, the challenge displays today’s state of the art in the field. We analyze the results using performance measures for segmentation and tracking that rank all participating methods. We also analyze the performance of all algorithms in terms of biological measures and their practical usability. Even though some methods score high in all technical aspects, not a single one obtains fully correct solutions. We show that methods that either take prior information into account using learning strategies or analyze cells in a global spatio-temporal video context perform better than other methods under the segmentation and tracking scenarios included in the challenge. PMID:29083403

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

NASA Technical Reports Server (NTRS)

Wolf, M.

1981-01-01

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.

An objective comparison of cell-tracking algorithms.

PubMed

Ulman, Vladimír; Maška, Martin; Magnusson, Klas E G; Ronneberger, Olaf; Haubold, Carsten; Harder, Nathalie; Matula, Pavel; Matula, Petr; Svoboda, David; Radojevic, Miroslav; Smal, Ihor; Rohr, Karl; Jaldén, Joakim; Blau, Helen M; Dzyubachyk, Oleh; Lelieveldt, Boudewijn; Xiao, Pengdong; Li, Yuexiang; Cho, Siu-Yeung; Dufour, Alexandre C; Olivo-Marin, Jean-Christophe; Reyes-Aldasoro, Constantino C; Solis-Lemus, Jose A; Bensch, Robert; Brox, Thomas; Stegmaier, Johannes; Mikut, Ralf; Wolf, Steffen; Hamprecht, Fred A; Esteves, Tiago; Quelhas, Pedro; Demirel, Ömer; Malmström, Lars; Jug, Florian; Tomancak, Pavel; Meijering, Erik; Muñoz-Barrutia, Arrate; Kozubek, Michal; Ortiz-de-Solorzano, Carlos

2017-12-01

We present a combined report on the results of three editions of the Cell Tracking Challenge, an ongoing initiative aimed at promoting the development and objective evaluation of cell segmentation and tracking algorithms. With 21 participating algorithms and a data repository consisting of 13 data sets from various microscopy modalities, the challenge displays today's state-of-the-art methodology in the field. We analyzed the challenge results using performance measures for segmentation and tracking that rank all participating methods. We also analyzed the performance of all of the algorithms in terms of biological measures and practical usability. Although some methods scored high in all technical aspects, none obtained fully correct solutions. We found that methods that either take prior information into account using learning strategies or analyze cells in a global spatiotemporal video context performed better than other methods under the segmentation and tracking scenarios included in the challenge.

Shikonin Inhibites Migration and Invasion of Thyroid Cancer Cells by Downregulating DNMT1

PubMed Central

Zhang, Yue; Sun, Bin; Huang, Zhi

2018-01-01

Background Shikonin is a component of Chinese herbal medicine. The aim of this study was to investigate the effects of shikonin on cell migration of papillary thyroid cancer cells of the TPC-1 cell line in vitro and expression levels of the phosphate and tensin homolog deleted on chromosome 10 (PTEN) and DNA methyltransferase 1 (DNMT1) genes. Material/Methods The Cell Counting Kit-8 (CCK-8) assay was performed to evaluate the proliferation of TPC-1 papillary thyroid cancer cells, and the normal thyroid cells, HTori-3, in vitro. A transwell motility assay was used to analyze the migration of TPC-1 cells. Western blot was performed to determine the expression levels of PTEN and DNMT1 genes. A methylation-specific polymerase chain reaction (PCR) (MSP) assay was used to evaluate the methylation of PTEN. Results Following treatment with shikonin, the cell survival rate of TPC-1 cells decreased in a dose-dependent manner; the inhibitory effects on HTori-3 cells were less marked. Shikonin inhibited TPC-1 cell migration and invasion in a dose-dependent manner. The methylation of PTEN was suppressed by shikonin, which also reduced the expression of DNMT1 in a dose-dependent manner, and increased the expression of PTEN. Overexpression of DNMT1 promoted the migration of TPC-1 cells and the methylation of PTEN. Levels of protein expression of PTEN in TPC-1 cells treated with shikonin decreased, and were increased by DNMT1 knockdown. Conclusions Shikonin suppressed the expression of DNMT1, reduced PTEN gene methylation, and increased PTEN protein expression, leading to the inhibition of TPC-1 cell migration. PMID:29389913

An electrochemical rebalance cell for Redox systems

NASA Technical Reports Server (NTRS)

Acevedo, J. C.; Stalnaker, D. K.

1983-01-01

An electrochemical rebalance cell for maintaining electrochemical balance, at the system level, of the acidified aqueous iron chloride and chromium chloride reactant solutions in the redox energy storage system was constructed and evaluated. The electrochemical reaction for the cathode is Fe(+3) + e(-) yields Fe(+2), and that for the anode is 1/2H2 yields H(+) + e(-). The iron (carbon felt) electrode and the hydrogen (platinized carbon) electrode are separated by an anion exchange membrane. The performance of the rebalance cell is discussed as well as the assembly of a single rebalance cell and multicell stacks. Various cell configurations were tested and the results are presented and discussed. The rebalance cell was also used to demonstrate its ability, as a preparative tool, for making high purity solutions of soluble reduced metal ionic species. Preparations of titanium, copper, vanadium and chromium ions in acidified solutions were evaluated.

Comparison of cell wall polysaccharide hydrolysis by a dilute acid/enzymatic saccharification process and rumen microorganisms

USDA-ARS?s Scientific Manuscript database

Evaluation of biomass crops for breeding or pricing purposes requires an assay that predicts performance of biomass in the bioenergy conversion process. Cell wall polysaccharide hydrolysis by dilute sulfuric acid pretreatment at 121 degrees C followed by cellulase hydrolysis for 72 h (CONV) and in v...

Performance evaluation of 4 measuring methods of ground-glass opacities for predicting the 5-year relapse-free survival of patients with peripheral nonsmall cell lung cancer: a multicenter study.

PubMed

Kakinuma, Ryutaro; Kodama, Ken; Yamada, Kouzo; Yokoyama, Akira; Adachi, Shuji; Mori, Kiyoshi; Fukuyama, Yasuro; Fukuda, Yasuro; Kuriyama, Keiko; Oda, Junichi; Oda, Junji; Noguchi, Masayuki; Matsuno, Yoshihiro; Yokose, Tomoyuki; Ohmatsu, Hironobu; Nishiwaki, Yutaka

2008-01-01

To evaluate the performance of 4 methods of measuring the extent of ground-glass opacities as a means of predicting the 5-year relapse-free survival of patients with peripheral nonsmall cell lung cancer (NSLC). Ground-glass opacities on thin-section computed tomographic images of 120 peripheral NSLCs were measured at 7 medical institutions by the length, area, modified length, and vanishing ratio (VR) methods. The performance (Az) of each method in predicting the 5-year relapse-free survival was evaluated using receiver operating characteristic analysis. The mean Az value obtained by the length, area, modified length, and VR methods in the receiver operating characteristic analyses was 0.683, 0.702, 0.728, and 0.784, respectively. The differences between the mean Az value obtained by the VR method and by the other 3 methods were significant. Vanishing ratio method was the most accurate predictor of the 5-year relapse-free survival of patients with peripheral NSLC.

Evaluation method for acoustic trapping performance by tracking motion of trapped microparticle

NASA Astrophysics Data System (ADS)

Lim, Hae Gyun; Ham Kim, Hyung; Yoon, Changhan

2018-05-01

We report a method to evaluate the performances of a single-beam acoustic tweezer using a high-frequency ultrasound transducer. The motion of a microparticle trapped by a 45-MHz single-element transducer was captured and analyzed to deduce the magnitude of trapping force. In the proposed method, the motion of a trapped microparticle was analyzed from a series of microscopy images to compute trapping force; thus, no additional equipment such as microfluidics is required. The method could be used to estimate the effective trapping force in an acoustic tweezer experiment to assess cell membrane deformability by attaching a microbead to the surface of a cell and tracking the motion of the trapped bead, which is similar to a bead-based assay that uses optical tweezers. The results showed that the trapping force increased with increasing acoustic intensity and duty factor, but the force eventually reached a plateau at a higher acoustic intensity. They demonstrated that this method could be used as a simple tool to evaluate the performance and to optimize the operating conditions of acoustic tweezers.

The Biological Properties of OGI Surfaces Positively Act on Osteogenic and Angiogenic Commitment of Mesenchymal Stem Cells

PubMed Central

Bressan, Eriberto; Gardin, Chiara; Ferroni, Letizia; Soldini, Maria Costanza; Mandelli, Federico; Soldini, Claudio

2017-01-01

Osteogenesis process displays a fundamental role during dental implant osteointegration. In the present work, we studied the influence of Osteon Growth Induction (OGI) surface properties on the angiogenic and osteogenic behaviors of Mesenchymal Stem cells (MSC). MSC derived from dental pulp and HUVEC (Human Umbilical Vein Endothelial Cells) were grown in on OGI titanium surfaces, and cell proliferation and DNA synthesis were evaluated by MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide] test and DNA quantification. Gene expression has been performed in order to evaluate the presence of mRNA related to endothelial and osteogenesis markers. Moreover, morphological and biochemical analyses of osteogenesis commitments has been performed. On OGI surfaces, MSC and HUVEC are able to proliferate. Gene expression profiler confirms that MSC on OGI surfaces are able to express endothelial and osteogenic markers, and that these expression are higher compared the expression on control surfaces. In conclusion On OGI surfaces proliferation, expression and morphological analyses of angiogenesis-associated markers in MSC are promoted. This process induces an increasing on their osteogenesis commitment. PMID:29149082

Field Performance versus Standard Test Condition Efficiency of Tandem Solar Cells and the Singular Case of Perovskites/Silicon Devices.

PubMed

Dupré, Olivier; Niesen, Bjoern; De Wolf, Stefaan; Ballif, Christophe

2018-01-18

Multijunction cells may offer a cost-effective route to boost the efficiency of industrial photovoltaics. For any technology to be deployed in the field, its performance under actual operating conditions is extremely important. In this perspective, we evaluate the impact of spectrum, light intensity, and module temperature variations on the efficiency of tandem devices with crystalline silicon bottom cells with a particular focus on perovskite top cells. We consider devices with different efficiencies and calculate their energy yields using field data from Denver. We find that annual losses due to differences between operating conditions and standard test conditions are similar for single-junction and four-terminal tandem devices. The additional loss for the two-terminal tandem configuration caused by current mismatch reduces its performance ratio by only 1.7% when an optimal top cell bandgap is used. Additionally, the unusual bandgap temperature dependence of perovskites is shown to have a positive, compensating effect on current mismatch.

Novel method for evaluation of natural dyes in DSSC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lakshmi, M.; Kavitha, S.; Paul, Mercyleena

Dye sensitized Solar Cell (DSSC) is presently centered on Ruthenium based dyes. Recent research is diverted to explore the potential of natural dyes in replacing the conventional dyes. In this work we have chosen few natural dyes, which when coated on TiO{sub 2} leads to increase in absorption capacity of TiO{sub 2}. Co-relation of absorption and electrochemical properties of natural dyes gives a scientific insight of the probable performance of a dye, even without fabricating a cell. We have tried to compare this predictions based on HOMO-LUMO energy levels with the real cell performance. Measurements of cell parameters suggest thatmore » there is scope for further research in this area.« less

Evaluation studies on carbon supported catalysts for oxygen reduction in alkaline medium

NASA Technical Reports Server (NTRS)

Srinivasan, Vakula S.; Singer, Joseph

1986-01-01

This paper describes tests designed to predict the performance of fuel cell electrodes, as applied to an alkaline oxygen-fuel cell having specially fabricated porous-carbon electrodes with various amounts of dispersed platinum or gold as active catalysts. The tests are based on information obtained from the techniques of cyclic voltammetry and polarization. The parameters obtained from cyclic voltammetry were of limited use in predicting fuel cell performance of the cathode. On the other hand, half-cell polarization measurements offered close simulation of the oxygen electrode, although a predictor of the electrode life is still lacking. The very low polarization of the Au-10 percent Pt catalytic electrode suggests that single-phase catalysts should be considered.

Silicon solar cell process development, fabrication and analysis

NASA Technical Reports Server (NTRS)

Minahan, J. A.

1981-01-01

The fabrication of solar cells from several unconventional silicon materials is described, and cell performance measured and analyzed. Unconventional materials evaluated are edge defined film fed grown (EFG), heat exchanger method (HEM), dendritic web grown, and continuous CZ silicons. Resistivity, current voltage, and spectral sensitivity of the cells were measured. Current voltage was measured under AM0 and AM1 conditions. Maximum conversion efficiencies of cells fabricated from these and other unconventional silicons were compared and test results analyzed. The HEM and continuous CZ silicon were found to be superior to silicon materials considered previously.

Evaluation program for secondary spacecraft cells: Seventeenth annual report of cycle life test

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1981-01-01

Acceptance tests were conducted on nickel cadmium, silver cadmium, and silver zinc cells to insure that all cells put into the life cycle program meet the specifications outlined in the respective purchase contracts. Statistical information is presented on cell performance characteristics and limitations. Weaknesses discovered in cell design are reported and aid in research and development efforts toward improving the reliability of space batteries. Battery weaknesses encountered in satellite programs such as IMP, NIMBUS, OGO, OAO, SAS, and TETR were studied and remedied through special tests.

NASA Glenn Research Center Solar Cell Experiment Onboard the International Space Station

NASA Technical Reports Server (NTRS)

Myers, Matthew G.; Wolford, David S.; Prokop, Norman F.; Krasowski, Michael J.; Parker, David S.; Cassidy, Justin C.; Davies , William E.; Vorreiter, Janelle O.; Piszczor, Michael F.; Mcnatt, Jeremiah S.;

Evaluation of 20 Ah Li Ion Cells

NASA Technical Reports Server (NTRS)

Smart, Marshall; Ratnakumar, B. V.; Huang, Charles K.; Surampudi, S.; Hill, Carole; Radzykewycz, Dan T.; Marsh, Richard A.

1998-01-01

Lithium ion cells of 20 Ah capacity were fabricated by Bluestar Advanced Technology Corporation, Canada under a developmental contract from US Air Force. In this paper, we report our studies on the evaluation of these cells under various test conditions. These include generic test conditions such as discharges and charges at different temperatures to understand the rate-limiting processes in the discharge/charge processes as a function of temperature, and cycle life under standard cycling conditions (100% DOD) at ambient temperature. In addition, tests are being done to ascertain the performance of the cells in the Mars 2001 Lander application, which includes pulse testing of the cells at 60 A and 40 A loads for 100 mS and 1 min., respectively at different states of charge and temperatures, and cycling at low temperature at partial depths of discharge.

Evaluation program for secondary spacecraft cells: Acceptance test of McDonnell-Douglas, Astropower division, 40.0 ampere hour silver-zinc cells

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1971-01-01

The development of an inorganic separator material for use in construction of 40 ampere-hour silver zinc cells is discussed. Acceptance tests were conducted to determine real quality, physical defects and ampere-hour capacity. All acceptance tests were performed at an ambient temperature of 23 to 27 C at existing relative humidity and atmospheric pressure. Of the 63 cells tested, only one failed to meet the equipment specifications.

The establishment of a production-ready manufacturing process utilizing thin silicon substrates for solar cells

NASA Technical Reports Server (NTRS)

Pryor, R. A.

1980-01-01

Three inch diameter Czochralski silicon substrates sliced directly to 5 mil, 8 mil, and 27 mil thicknesses with wire saw techniques were procured. Processing sequences incorporating either diffusion or ion implantation technologies were employed to produce n+p or n+pp+ solar cell structures. These cells were evaluated for performance, ease of fabrication, and cost effectiveness. It was determined that the use of 7 mil or even 4 mil wafers would provide near term cost reductions for solar cell manufacturers.

Development and fabrication of large vented nickel-zinc cells

NASA Technical Reports Server (NTRS)

Donnel, C. P., III

1975-01-01

A preliminary cell design for a 300AH vented nickel-zinc cell was established based on volume requirements and cell component materials selected by NASA Lewis Research Center. A 100AH cell configuration was derived from the 300AH cell design utilizing the same size electrodes, separators, and cell terminal hardware. The first cells fabricated were four groups of three cells each in the 100AH size. These 100AH experimental nickel-zinc cells had as common components the nickel positive electrodes (GFM), flexible inorganic separator (GFM) bags on the negative electrodes, pressed powder zinc oxide electrodes, and cell containers with hardware. The variations introduced were four differing electrolyte absorber (interseparator) systems used to encase the nickel positive electrodes of each cell group. The four groups of 100AH experimental vented nickel-zinc cells were tested to determine, based on cell performance, the best two interseparator systems. Using the two interseparator systems, two groups of experimental 300AH cells were fabricated. Each group of three cells differed only in the interseparator material used. The six cells were filled, formed and tested to evaluate the interseparator materials and investigate the performance characteristics of the 300AH cell configuration and its components.

Current automated 3D cell detection methods are not a suitable replacement for manual stereologic cell counting

PubMed Central

Schmitz, Christoph; Eastwood, Brian S.; Tappan, Susan J.; Glaser, Jack R.; Peterson, Daniel A.; Hof, Patrick R.

2014-01-01

Stereologic cell counting has had a major impact on the field of neuroscience. A major bottleneck in stereologic cell counting is that the user must manually decide whether or not each cell is counted according to three-dimensional (3D) stereologic counting rules by visual inspection within hundreds of microscopic fields-of-view per investigated brain or brain region. Reliance on visual inspection forces stereologic cell counting to be very labor-intensive and time-consuming, and is the main reason why biased, non-stereologic two-dimensional (2D) “cell counting” approaches have remained in widespread use. We present an evaluation of the performance of modern automated cell detection and segmentation algorithms as a potential alternative to the manual approach in stereologic cell counting. The image data used in this study were 3D microscopic images of thick brain tissue sections prepared with a variety of commonly used nuclear and cytoplasmic stains. The evaluation compared the numbers and locations of cells identified unambiguously and counted exhaustively by an expert observer with those found by three automated 3D cell detection algorithms: nuclei segmentation from the FARSIGHT toolkit, nuclei segmentation by 3D multiple level set methods, and the 3D object counter plug-in for ImageJ. Of these methods, FARSIGHT performed best, with true-positive detection rates between 38 and 99% and false-positive rates from 3.6 to 82%. The results demonstrate that the current automated methods suffer from lower detection rates and higher false-positive rates than are acceptable for obtaining valid estimates of cell numbers. Thus, at present, stereologic cell counting with manual decision for object inclusion according to unbiased stereologic counting rules remains the only adequate method for unbiased cell quantification in histologic tissue sections. PMID:24847213

FIELD-SCALE EVALUATION OF IN SITU COSOLVENT FLUSHING FOR ENCHANCED AQUIFER REMEDIATION

EPA Science Inventory

A comprehensive, field-scale evaluation of in situ cosolvent flushing for enhanced remediation of nonaqueous phase liquid (NAPL)-contaminated aquifers was performed in a hydraulically isolated test cell (about 4.3 m x 3.6 m) constructed at a field site at Hill Air Force Base, Uta...

Activity and Durability of Iridium Nanoparticles in the Oxygen Evolution Reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alia, Shaun M.; Rasimick, Brian; Ngo, Chilan

Unsupported iridium (Ir) nanoparticles, that serve as standard oxygen evolution reaction (OER) catalysts in acidic electrolyzers, were investigated for electrochemical performance and durability in rotating disk electrode (RDE) half-cells. Fixed potential holds and potential cycling were applied to probe the durability of Ir nanoparticles, and performance losses were found to be driven by particle growth (coarsening) at moderate potential (1.4 to 1.6 V) and Ir dissolution at higher potential (>/=1.8 V). Several different commercially available samples were evaluated and standardized conditions for performance comparison are reported. In conclusion, the electrocatalyst RDE results have also been compared to results obtained formore » performance and durability in electrolysis cells.« less

Activity and Durability of Iridium Nanoparticles in the Oxygen Evolution Reaction

DOE PAGES

Alia, Shaun M.; Rasimick, Brian; Ngo, Chilan; ...

2016-07-15

Unsupported iridium (Ir) nanoparticles, that serve as standard oxygen evolution reaction (OER) catalysts in acidic electrolyzers, were investigated for electrochemical performance and durability in rotating disk electrode (RDE) half-cells. Fixed potential holds and potential cycling were applied to probe the durability of Ir nanoparticles, and performance losses were found to be driven by particle growth (coarsening) at moderate potential (1.4 to 1.6 V) and Ir dissolution at higher potential (>/=1.8 V). Several different commercially available samples were evaluated and standardized conditions for performance comparison are reported. In conclusion, the electrocatalyst RDE results have also been compared to results obtained formore » performance and durability in electrolysis cells.« less

Fatty acid is a potential agent for bone tissue induction: In vitro and in vivo approach.

PubMed

Cardoso, Guinea Bc; Chacon, Erivelto; Chacon, Priscila Gl; Bordeaux-Rego, Pedro; Duarte, Adriana Ss; Saad, Sara T Olalla; Zavaglia, Cecilia Ac; Cunha, Marcelo R

2017-12-01

Our hypothesis was to investigate the fatty acid potential as a bone induction factor. In vitro and in vivo studies were performed to evaluate this approach. Oleic acid was used in a 0.5 wt.% concentration. Polycaprolactone was used as the polymeric matrix by combining solvent-casting and particulate-leaching techniques, with a final porosity of 70 wt.%, investigated by SEM images. Contact angle measurements were produced to investigate the influence of oleic acid on polycaprolactone chains. Cell culture was performed using adipocyte-derived stem cells to evaluate biocompatibility and bioactivity properties. In addition, in vivo studies were performed to evaluate the induction potential of oleic acid addition. Adipocyte-derived stem cells were used to provide differentiation after 21 days of culture. Likewise, information were obtained with in vivo data and cellular invagination was observed on both scaffolds (polycaprolactone and polycaprolactone /oleic acid); interestingly, the scaffold with oleic acid addition demonstrated that cellular migrations are not related to the surrounding tissue, indicating bioactive potential. Our hypothesis is that fatty acid may be used as a potential induction factor for bone tissue engineering. The study's findings indicate oleic acid as a possible agent for bone induction, according to data on cell differentiation, proliferation, and migration. Impact statement The biomaterial combined in this study on bone regeneration is innovative and shows promising results in the treatment of bone lesions. Polycaprolactone (PCL) and oleic acid have been studied separately. In this research, we combined biomaterials to assess the stimulus and the speed of bone healing.

Acacia catechu ethanolic bark extract induces apoptosis in human oral squamous carcinoma cells.

PubMed

Lakshmi, Thangavelu; Ezhilarasan, Devaraj; Vijayaragavan, Rajagopal; Bhullar, Sukhwinder Kaur; Rajendran, Ramasamy

2017-01-01

Oral cancer is in approximately 30% of all cancers in India. This study was conducted to evaluate the cytotoxic activity of ethanolic extract of Acacia catechu bark (ACB) against human squamous cell carcinoma cell line-25 (SCC-25). Cytotoxic effect of ACB extract was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide assay. A. catechu extract was treated SCC-25 cells with 25 and 50 μg/mL for 24 h. Apoptosis markers such as caspases-8 and 9, bcl-2, bax, and cytochrome c (Cyt-c) were done by RT-PCR. Morphological changes of ACB treated cells were evaluated using acridine orange/ethidium bromide (AO/EB) dual staining. Nuclear morphology and DNA fragmentation were evaluated using propidium iodide (PI) staining. Further, cell cycle analysis was performed using flow cytometry. A. catechu treatment caused cytotoxicity in SCC-25 cells with an IC 50 of 52.09 μg/mL. Apoptotic marker gene expressions were significantly increased on ACB treatment. Staining with AO/EB and PI shows membrane blebbing and nuclear membrane distortion, respectively, and it confirms the apoptosis induction in SCC-25 cells. These results suggest that ACB extract can be used as a modulating agent in oral squamous cell carcinoma.

Plasmonic Light Trapping in Thin-Film Solar Cells: Impact of Modeling on Performance Prediction

PubMed Central

Micco, Alberto; Pisco, Marco; Ricciardi, Armando; Mercaldo, Lucia V.; Usatii, Iurie; La Ferrara, Vera; Delli Veneri, Paola; Cutolo, Antonello; Cusano, Andrea

2015-01-01

We present a comparative study on numerical models used to predict the absorption enhancement in thin-film solar cells due to the presence of structured back-reflectors exciting, at specific wavelengths, hybrid plasmonic-photonic resonances. To evaluate the effectiveness of the analyzed models, they have been applied in a case study: starting from a U-shaped textured glass thin-film, µc-Si:H solar cells have been successfully fabricated. The fabricated cells, with different intrinsic layer thicknesses, have been morphologically, optically and electrically characterized. The experimental results have been successively compared with the numerical predictions. We have found that, in contrast to basic models based on the underlying schematics of the cell, numerical models taking into account the real morphology of the fabricated device, are able to effectively predict the cells performances in terms of both optical absorption and short-circuit current values.

Silicon Solar Cell Process Development, Fabrication and Analysis, Phase 1

NASA Technical Reports Server (NTRS)

Yoo, H. I.; Iles, P. A.; Tanner, D. P.

1979-01-01

Solar cells from RTR ribbons, EFG (RF and RH) ribbons, dendritic webs, Silso wafers, cast silicon by HEM, silicon on ceramic, and continuous Czochralski ingots were fabricated using a standard process typical of those used currently in the silicon solar cell industry. Back surface field (BSF) processing and other process modifications were included to give preliminary indications of possible improved performance. The parameters measured included open circuit voltage, short circuit current, curve fill factor, and conversion efficiency (all taken under AM0 illumination). Also measured for typical cells were spectral response, dark I-V characteristics, minority carrier diffusion length, and photoresponse by fine light spot scanning. the results were compared to the properties of cells made from conventional single crystalline Czochralski silicon with an emphasis on statistical evaluation. Limited efforts were made to identify growth defects which will influence solar cell performance.

Histopathologic and Immunohistochemical Sequelae of Bariatric Embolization in a Porcine Model

PubMed Central

Paxton, Ben E.; Alley, Christopher L.; Crow, Jennifer H.; Burchette, James; Weiss, Clifford R.; Kraitchman, Dara L.; Arepally, Aravind; Kim, Charles Y.

2014-01-01

Purpose To evaluate the histopathologic sequelae of bariatric embolization on the gastric mucosa and to correlate with immunohistochemical evaluation of the gastric fundus, antrum, and duodenum. Materials and Methods This study was performed on 12 swine stomach and duodenum specimens after necropsy. Of the 12 swine, 6 had previously undergone bariatric embolization of the gastric fundus, and the 6 control swine had undergone a sham procedure with saline. Gross pathologic, histopathologic, and immunohistochemical examinations of the stomach and duodenum were performed. Specifically, mucosal integrity, fibrosis, ghrelin-expressing cells, and gastrin-expressing cells were assessed. Results Gross and histopathologic evaluation of treatment animals showed healing or healed mucosal ulcers in 50% of animals, with gastritis in 100% of treatment animals and in five of six control animals. The ghrelin-immunoreactive mean cell density was significantly lower in the gastric fundus in the treated animals compared with control animals (15.3 vs 22.0, P < .01) but similar in the gastric antrum (9.3 vs 14.3, P = .08) and duodenum (8.5 vs 8.6, P = .89). The gastrin-expressing cell density was significantly lower in the antrum of treated animals compared with control animals (82.2 vs 126.4, P = .03). A trend toward increased fibrosis was suggested in the gastric fundus of treated animals compared with controls (P = .07). Conclusions Bariatric embolization resulted in a significant reduction in ghrelin-expressing cells in the gastric fundus without evidence of upregulation of ghrelin-expressing cells in the duodenum. Healing ulcerations in half of treated animals underscores the need for additional refinement of this procedure. PMID:24462005

The effects of biodegradable poly(lactic-co-glycolic acid)-based microspheres loaded with quercetin on stemness, viability and osteogenic differentiation potential of stem cell spheroids.

PubMed

Lee, H; Nguyen, T T; Kim, M; Jeong, J-H; Park, J-B

2018-05-31

Quercetin has been reported to exert many beneficial effects on the protection against various diseases, such as diabetes, cancer, and inflammation. The aim of this study is to evaluate the potential osteogenic differentiation ability of mesenchymal stem cells in the presence of quercetin. Quercetin-loaded poly(lactic-co-glycolic acid) microspheres were prepared using an electrospraying technique. Characterization of the microspheres was evaluated with a scanning electron microscope and release profile. Three-dimensional cell spheroids were fabricated using silicon elastomer-based concave microwells. Qualitative results of cellular viability were seen under a confocal microscope, and quantitative cellular viability was evaluated using the Cell Counting Kit-8 assay. The alkaline phosphatase activity and Alizarin Red S staining were performed. A quantitative real-time polymerase chain reaction and a western blot analysis were performed. Spheroids were well formed irrespective of quercetin concentration. Most of the cells in spheroids emitted green fluorescence, and the morphology was round without significant changes. The application of quercetin-loaded microspheres produced a significant increase in the alkaline phosphatase activity. The real-time polymerase chain reaction results showed a significant increase in Runx2, and western blot results showed higher expression of Runx2 protein expression. Biodegradable microspheres loaded with quercetin produced prolonged release profiles with increased mineralization. Microspheres loaded with quercetin can be used for the enhancement of osteoblastic differentiation in cell therapy. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Preparation and evaluation of advanced electrocatalysts for phosphoric acid fuel cells

NASA Technical Reports Server (NTRS)

Stonehart, P.; Baris, J.; Hochmuth, J.; Pagliaro, P.

1981-01-01

The highest performance fuel cell cathode electrocatalyst combination ever observed gives 755 mV vs hydrogen at 100 ASF on air at 180 C and shows a potential improvement to 775 mV vs hydrogen for better electrode structures. A pressurized fuel cell (UTC at 5 atm) would then give 805 mV at 320 ASF and 180 C. Another activity diagnostic is the performance of this electrocatalyst on oxygen at 900 mV vs hydrogen. The value for electrocatalyst is 44 mA per milligram of platinum and is projected to reach 60 mA per milligram of platinum with improved electrode structures. Since the electrocatalyst surface area and the electrode structure are not yet optimized there is considerable room for performance enhancement beyond these values, especially at higher temperatures.

Thymol Elicits HCT-116 Colorectal Carcinoma Cell Death Through Induction of Oxidative Stress.

PubMed

Chauhan, Anil Kumar; Bahuguna, Ashutosh; Paul, Souren; Kang, Sun Chul

2018-02-07

Colon cancer is one of the most deadly and common carcinomas occurring worldwide and there have been many attempts to treat this cancer. The present work was designed in order to evaluate thymol as a potent drug against colon cancer. Cytotoxicity of thymol at different concentrations was evaluated against a human colon carcinoma cell line (HCT-116 cells). Fluorescent staining was carried out to evaluate the level of ROS as well as mitochondrial and DNA fragmentation and immunoblot analysis were performed to confirm apoptosis and mitoptosis. Results of the study demonstrated that thymol efficiently created an oxidative stress environment inside HCT-116 cells, a colorectal carcinoma cell line, through induction of ROS production along with intense damage to DNA and mitochondria, as observed through Hoechst and rhodamine 123 staining, respectively. Moreover, expression of PARP-1, p-JNK, cytochrome-C and caspase-3 proteins was up-regulated, suggesting HCT-116 cells underwent mitoptotic cell death. Therefore, thymol could be used as a potent drug against colon cancer due to its lower toxicity and prevalence in natural medicinal plants. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Single walled carbon nanotube composites for bone tissue engineering.

PubMed

Gupta, Ashim; Woods, Mia D; Illingworth, Kenneth David; Niemeier, Ryan; Schafer, Isaac; Cady, Craig; Filip, Peter; El-Amin, Saadiq F

2013-09-01

The purpose of this study was to develop single walled carbon nanotubes (SWCNT) and poly lactic-co-glycolic acid (PLAGA) composites for orthopedic applications and to evaluate the interaction of human stem cells (hBMSCs) and osteoblasts (MC3T3-E1 cells) via cell growth, proliferation, gene expression, extracellular matrix production and mineralization. PLAGA and SWCNT/PLAGA composites were fabricated with various amounts of SWCNT (5, 10, 20, 40, and 100 mg), characterized and degradation studies were performed. Cells were seeded and cell adhesion/morphology, growth/survival, proliferation and gene expression analysis were performed to evaluate biocompatibility. Imaging studies demonstrated uniform incorporation of SWCNT into the PLAGA matrix and addition of SWCNT did not affect the degradation rate. Imaging studies revealed that MC3T3-E1 and hBMSCs cells exhibited normal, non-stressed morphology on the composites and all were biocompatible. Composites with 10 mg SWCNT resulted in highest rate of cell proliferation (p < 0.05) among all composites. Gene expression of alkaline phosphatase, collagen I, osteocalcin, osteopontin, Runx-2, and Bone Sialoprotein was observed on all composites. In conclusion, SWCNT/PLAGA composites imparted beneficial cellular growth capabilities and gene expression, and mineralization abilities were well established. These results demonstrate the potential of SWCNT/PLAGA composites for musculoskeletal regeneration and bone tissue engineering (BTE) and are promising for orthopedic applications. Copyright © 2013 Orthopaedic Research Society.

Macular Ganglion Cell Imaging Study: Covariate Effects on the Spectral Domain Optical Coherence Tomography for Glaucoma Diagnosis

PubMed Central

Jeong, Jae Hoon; Choi, Yun Jeong; Park, Ki Ho; Kim, Dong Myung

2016-01-01

Purpose To evaluate the effect of multiple covariates on the diagnostic performance of the Cirrus high-definition optical coherence tomography (HD-OCT) for glaucoma detection. Methods A prospective case-control study was performed and included 173 recently diagnosed glaucoma patients and 63 unaffected individuals from the Macular Ganglion Cell Imaging Study. Regression analysis of receiver operating characteristic were conducted to evaluate the influence of age, spherical equivalent, axial length, optic disc size, and visual field index on the macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) measurements. Results Disease severity, as measured by visual field index, had a significant effect on the diagnostic performance of all Cirrus HD-OCT parameters. Age, axial length and optic disc size were significantly associated with diagnostic accuracy of average peripapillary RNFL thickness, whereas axial length had a significant effect on the diagnostic accuracy of average GCIPL thickness. Conclusions Diagnostic performance of the Cirrus HD-OCT may be more accurate in the advanced stages of glaucoma than at earlier stages. A smaller optic disc size was significantly associated with improved the diagnostic ability of average RNFL thickness measurements; however, GCIPL thickness may be less affected by age and optic disc size. PMID:27490718

Transplantation of BDNF-Secreting Mesenchymal Stem Cells Provides Neuroprotection in Chronically Hypertensive Rat Eyes

PubMed Central

Harper, Matthew M.; Grozdanic, Sinisa D.; Blits, Bas; Kuehn, Markus H.; Zamzow, Daniel; Buss, Janice E.; Kardon, Randy H.; Sakaguchi, Donald S.

2011-01-01

Purpose. To evaluate the ability of mesenchymal stem cells (MSCs) engineered to produce and secrete brain-derived neurotrophic factor (BDNF) to protect retinal function and structure after intravitreal transplantation in a rat model of chronic ocular hypertension (COH). Methods. COH was induced by laser cauterization of trabecular meshwork and episcleral veins in rat eyes. COH eyes received an intravitreal transplant of MSCs engineered to express BDNF and green fluorescent protein (BDNF-MSCs) or just GFP (GFP-MSCs). Computerized pupillometry and electroretinography (ERG) were performed to assess optic nerve and retinal function. Quantification of optic nerve damage was performed by counting retinal ganglion cells (RGCs) and evaluating optic nerve cross-sections. Results. After transplantation into COH eyes, BDNF-MSCs preserved significantly more retina and optic nerve function than GFP-MSC–treated eyes when pupil light reflex (PLR) and ERG function were evaluated. PLR analysis showed significantly better function (P = 0.03) in BDNF-MSC–treated eyes (operated/control ratio = 63.00% ± 11.39%) than GFP-MSC–treated eyes (operated/control ratio = 31.81% ± 9.63%) at 42 days after surgery. The BDNF-MSC–transplanted eyes also displayed a greater level of RGC preservation than eyes that received the GFP-MSCs only (RGC cell counts: BDNF-MSC–treated COH eyes, 112.2 ± 19.39 cells/section; GFP-MSC–treated COH eyes, 52.21 ± 11.54 cells/section; P = 0.01). Conclusions. The authors have demonstrated that lentiviral-transduced BDNF-producing MSCs can survive in eyes with chronic hypertension and can provide retina and optic nerve functional and structural protection. Transplantation of BDNF-producing stem cells may be a viable treatment strategy for glaucoma. PMID:21498611

Training echo state networks for rotation-invariant bone marrow cell classification.

PubMed

Kainz, Philipp; Burgsteiner, Harald; Asslaber, Martin; Ahammer, Helmut

2017-01-01

The main principle of diagnostic pathology is the reliable interpretation of individual cells in context of the tissue architecture. Especially a confident examination of bone marrow specimen is dependent on a valid classification of myeloid cells. In this work, we propose a novel rotation-invariant learning scheme for multi-class echo state networks (ESNs), which achieves very high performance in automated bone marrow cell classification. Based on representing static images as temporal sequence of rotations, we show how ESNs robustly recognize cells of arbitrary rotations by taking advantage of their short-term memory capacity. The performance of our approach is compared to a classification random forest that learns rotation-invariance in a conventional way by exhaustively training on multiple rotations of individual samples. The methods were evaluated on a human bone marrow image database consisting of granulopoietic and erythropoietic cells in different maturation stages. Our ESN approach to cell classification does not rely on segmentation of cells or manual feature extraction and can therefore directly be applied to image data.

Performance of a Limiting-Antigen Avidity Enzyme Immunoassay for Cross-Sectional Estimation of HIV Incidence in the United States

PubMed Central

Konikoff, Jacob; Brookmeyer, Ron; Longosz, Andrew F.; Cousins, Matthew M.; Celum, Connie; Buchbinder, Susan P.; Seage, George R.; Kirk, Gregory D.; Moore, Richard D.; Mehta, Shruti H.; Margolick, Joseph B.; Brown, Joelle; Mayer, Kenneth H.; Koblin, Beryl A.; Justman, Jessica E.; Hodder, Sally L.; Quinn, Thomas C.; Eshleman, Susan H.; Laeyendecker, Oliver

2013-01-01

Background A limiting antigen avidity enzyme immunoassay (HIV-1 LAg-Avidity assay) was recently developed for cross-sectional HIV incidence estimation. We evaluated the performance of the LAg-Avidity assay alone and in multi-assay algorithms (MAAs) that included other biomarkers. Methods and Findings Performance of testing algorithms was evaluated using 2,282 samples from individuals in the United States collected 1 month to >8 years after HIV seroconversion. The capacity of selected testing algorithms to accurately estimate incidence was evaluated in three longitudinal cohorts. When used in a single-assay format, the LAg-Avidity assay classified some individuals infected >5 years as assay positive and failed to provide reliable incidence estimates in cohorts that included individuals with long-term infections. We evaluated >500,000 testing algorithms, that included the LAg-Avidity assay alone and MAAs with other biomarkers (BED capture immunoassay [BED-CEIA], BioRad-Avidity assay, HIV viral load, CD4 cell count), varying the assays and assay cutoffs. We identified an optimized 2-assay MAA that included the LAg-Avidity and BioRad-Avidity assays, and an optimized 4-assay MAA that included those assays, as well as HIV viral load and CD4 cell count. The two optimized MAAs classified all 845 samples from individuals infected >5 years as MAA negative and estimated incidence within a year of sample collection. These two MAAs produced incidence estimates that were consistent with those from longitudinal follow-up of cohorts. A comparison of the laboratory assay costs of the MAAs was also performed, and we found that the costs associated with the optimal two assay MAA were substantially less than with the four assay MAA. Conclusions The LAg-Avidity assay did not perform well in a single-assay format, regardless of the assay cutoff. MAAs that include the LAg-Avidity and BioRad-Avidity assays, with or without viral load and CD4 cell count, provide accurate incidence estimates. PMID:24386116

Traits, properties, and performance: how woody plants combine hydraulic and mechanical functions in a cell, tissue, or whole plant.

PubMed

Lachenbruch, Barbara; McCulloh, Katherine A

2014-12-01

This review presents a framework for evaluating how cells, tissues, organs, and whole plants perform both hydraulic and mechanical functions. The morphological alterations that affect dual functionality are varied: individual cells can have altered morphology; tissues can have altered partitioning to functions or altered cell alignment; and organs and whole plants can differ in their allocation to different tissues, or in the geometric distribution of the tissues they have. A hierarchical model emphasizes that morphological traits influence the hydraulic or mechanical properties; the properties, combined with the plant unit's environment, then influence the performance of that plant unit. As a special case, we discuss the mechanisms by which the proxy property wood density has strong correlations to performance but without direct causality. Traits and properties influence multiple aspects of performance, and there can be mutual compensations such that similar performance occurs. This compensation emphasizes that natural selection acts on, and a plant's viability is determined by, its performance, rather than its contributing traits and properties. Continued research on the relationships among traits, and on their effects on multiple aspects of performance, will help us better predict, manage, and select plant material for success under multiple stresses in the future. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Evaluating the quality of a cell counting measurement process via a dilution series experimental design.

PubMed

Sarkar, Sumona; Lund, Steven P; Vyzasatya, Ravi; Vanguri, Padmavathy; Elliott, John T; Plant, Anne L; Lin-Gibson, Sheng

2017-12-01

Cell counting measurements are critical in the research, development and manufacturing of cell-based products, yet determining cell quantity with accuracy and precision remains a challenge. Validating and evaluating a cell counting measurement process can be difficult because of the lack of appropriate reference material. Here we describe an experimental design and statistical analysis approach to evaluate the quality of a cell counting measurement process in the absence of appropriate reference materials or reference methods. The experimental design is based on a dilution series study with replicate samples and observations as well as measurement process controls. The statistical analysis evaluates the precision and proportionality of the cell counting measurement process and can be used to compare the quality of two or more counting methods. As an illustration of this approach, cell counting measurement processes (automated and manual methods) were compared for a human mesenchymal stromal cell (hMSC) preparation. For the hMSC preparation investigated, results indicated that the automated method performed better than the manual counting methods in terms of precision and proportionality. By conducting well controlled dilution series experimental designs coupled with appropriate statistical analysis, quantitative indicators of repeatability and proportionality can be calculated to provide an assessment of cell counting measurement quality. This approach does not rely on the use of a reference material or comparison to "gold standard" methods known to have limited assurance of accuracy and precision. The approach presented here may help the selection, optimization, and/or validation of a cell counting measurement process. Published by Elsevier Inc.

Fabrication and evaluation of 100 Ah cylindrical lithium ion battery for electric vehicle applications

NASA Astrophysics Data System (ADS)

Hyung, Yoo-Eup; Moon, Seong-In; Yum, Duk-Hyeng; Yun, Seong-Kyu

A total of 100 Ah class lithium ion cells with C/LiCoO 2 cell system for electric vehicles (EVs) was developed. EV-size lithium ion battery was developed by Sony, KERI/STC, SAFT, VARTA, Sanyo and Matsushita. GS battery and Hitachi have developed also stationary type large scale (70-80 Ah) lithium ion batteries. Lithium ion battery module for EVs was demonstrated by Sony/Nissan and KERI/STC in 1996. At present, the performance of developed EV-cells was up to 115 Wh/kg and 286 W/kg of specific power at 80% DOD. We assume our EV cells to have 248 and 242 km driving distance per one charge with DST-120 mode and ECE-15 mode, respectively. Finally, we performed safety/abuse tests of developed lithium ion cell.

Development of lithium diffused radiation resistant solar cells, part 2

NASA Technical Reports Server (NTRS)

Payne, P. R.; Somberg, H.

1971-01-01

The work performed to investigate the effect of various process parameters on the performance of lithium doped P/N solar cells is described. Effort was concentrated in four main areas: (1) the starting material, (2) the boron diffusion, (3) the lithium diffusion, and (4) the contact system. Investigation of starting material primarily involved comparison of crucible grown silicon (high oxygen content) and Lopex silicon (low oxygen content). In addition, the effect of varying growing parameters of crucible grown silicon on lithium cell output was also examined. The objective of the boron diffusion studies was to obtain a diffusion process which produced high efficiency cells with minimal silicon stressing and could be scaled up to process 100 or more cells per diffusion. Contact studies included investigating sintering of the TiAg contacts and evaluation of the contact integrity.

Full scale phosphoric acid fuel cell stack technology development

NASA Technical Reports Server (NTRS)

Christner, L.; Faroque, M.

1984-01-01

The technology development for phosphoric acid fuel cells is summarized. The preparation, heat treatment, and characterization of carbon composites used as bipolar separator plates are described. Characterization included resistivity, porosity, and electrochemical corrosion. High density glassy carbon/graphite composites performed well in long-term fuel cell endurance tests. Platinum alloy cathode catalysts and low-loaded platinum electrodes were evaluated in 25 sq cm cells. Although the alloys displayed an initial improvement, some of this improvement diminished after a few thousand hours of testing. Low platinum loading (0.12 mg/sq cm anodes and 0.3 mg/sq cm cathodes) performed nearly as well as twice this loading. A selectively wetproofed anode backing paper was tested in a 5 by 15 inch three-cell stack. This material may provide for acid volume expansion, acid storage, and acid lateral distribution.

ASSESSMENT OF TWO PHYSICALLY-BASED WATERSHED MODELS BASED ON THEIR PERFORMANCES OF SIMULATING WATER AND SEDIMENT MOVEMENT

EPA Science Inventory

Two physically based watershed models, GSSHA and KINEROS-2 are evaluated and compared for their performances on modeling flow and sediment movement. Each model has a different watershed conceptualization. GSSHA divides the watershed into cells, and flow and sediments are routed t...

Evaluation of the efficacy of the four tests (p16 immunochemistry, PCR, DNA and RNA In situ Hybridization) to evaluate a Human Papillomavirus infection in head and neck cancers: a cohort of 348 French squamous cell carcinomas.

PubMed

Augustin, Jérémy; Outh-Gauer, Sophie; Mandavit, Marion; Gasne, Cassandre; Grard, Ophélie; Denize, Thomas; Nervo, Marine; Mirghani, Haïtham; Laccourreye, Ollivier; Bonfils, Pierre; Bruneval, Patrick; Veyer, David; Péré, Hélène; Tartour, Eric; Badoual, Cécile

2018-04-20

It is now established that HPV plays a role in the development of a subset of head and neck squamous cell carcinomas (HNSCCs), notably oropharyngeal squamous cell carcinomas (SCCs). However, it is not clear which test one should use to detect HPV in oropharyngeal (OP) and non-OP SCCs. In this study, using 348 HNSCCs (126 OP SCCs and 222 non-OP SCCs), we evaluated diagnostic performances of different HPV tests in OP and non-OP SCCs: PCR, p16 immunostaining, in situ hybridization targeting DNA (DNA-CISH) and RNA (RNA-CISH), combined p16 + DNA-CISH, and combined p16 + RNA-CISH. HPV DNA (PCR) was detected in 26% of all tumors (44% of OP SCCs and 17% of non-OP SCCs). For OP SCCs, RNA-CISH was the most sensitive standalone test (88%), but p16 + RNA-CISH was even more sensitive (95%). Specificities were the same for RNA-CISH and DNA-CISH (97%) but it was better for p16 + RNA-CISH (100%). For non-OP SCCs, all tests had sensitivities below 50%, and RNA-CISH, DNA-CISH and p16 + DNA-CISH had respectively 100%, 97% and 99% specificities. As a standalone test, RNA-CISH is the most performant assay to detect HPV in OP SCCs, and combined p16 + RNA-CISH test slightly improves its performances. However, RNA-CISH has the advantage of being one single test. Like p16 and DNA-CISH, RNA-CISH performances are poor in non-OP SCCs to detect HPV, and combining tests does not improve performances. Copyright © 2018. Published by Elsevier Inc.

Cytotoxic and Immunomodulatory Potential Activity of Physalis peruviana Fruit Extracts on Cervical Cancer (HeLa) and Fibroblast (L929) Cells.

PubMed

Mier-Giraldo, Helen; Díaz-Barrera, Luis Eduardo; Delgado-Murcia, Lucy Gabriela; Valero-Valdivieso, Manuel Fernando; Cáez-Ramírez, Gabriela

2017-10-01

It was purposed to evaluate the biological potential of ethanol and isopropanol crude extracts of ripe Physalis peruviana fruits. Cytotoxic and immunomodulatory effects of the expression of interleukin-6, interleukin-8, and monocyte chemoattractant protein-1 (MCP-1) were evaluated on human cervical cancer (HeLa) and murine fibroblast (L929) cells. The composition was evaluated by high-performance liquid chromatography diode-array detection and high-performance liquid chromatography ultraviolet/visible detection. The presence of ursolic acid and rosmarinic acid was found in both solvents. However, gallic acid, quercetin, and epicatechin were higher in isopropanol extracts ( P < .05). The results indicated a relationship among the total polyphenol content, antioxidant activity, and cytotoxic activity that was dependent on the solvent used. Isopropanol extracts presented a half-maximal inhibition concentration value (IC 50 ) of 60.48 ± 3.8 μg/mL for HeLa cells and 66.62 ± 2.67 μg/mL for L929 fibroblasts. The extracts reduced the release of interleukin-6, interleukin-8, and MCP-1 in a dose-dependent manner. Extracts showed anticancer and immunomodulatory potential for new complementary pharmaceutical products development.

Cytotoxic and Immunomodulatory Potential Activity of Physalis peruviana Fruit Extracts on Cervical Cancer (HeLa) and Fibroblast (L929) Cells

PubMed Central

Mier-Giraldo, Helen; Díaz-Barrera, Luis Eduardo; Delgado-Murcia, Lucy Gabriela; Valero-Valdivieso, Manuel Fernando; Cáez-Ramírez, Gabriela

2017-01-01

It was purposed to evaluate the biological potential of ethanol and isopropanol crude extracts of ripe Physalis peruviana fruits. Cytotoxic and immunomodulatory effects of the expression of interleukin-6, interleukin-8, and monocyte chemoattractant protein-1 (MCP-1) were evaluated on human cervical cancer (HeLa) and murine fibroblast (L929) cells. The composition was evaluated by high-performance liquid chromatography diode-array detection and high-performance liquid chromatography ultraviolet/visible detection. The presence of ursolic acid and rosmarinic acid was found in both solvents. However, gallic acid, quercetin, and epicatechin were higher in isopropanol extracts (P < .05). The results indicated a relationship among the total polyphenol content, antioxidant activity, and cytotoxic activity that was dependent on the solvent used. Isopropanol extracts presented a half-maximal inhibition concentration value (IC50) of 60.48 ± 3.8 μg/mL for HeLa cells and 66.62 ± 2.67 μg/mL for L929 fibroblasts. The extracts reduced the release of interleukin-6, interleukin-8, and MCP-1 in a dose-dependent manner. Extracts showed anticancer and immunomodulatory potential for new complementary pharmaceutical products development. PMID:28719984

Initial evaluation of the use of USPIO cell labeling and noninvasive MR monitoring of human tissue-engineered vascular grafts in vivo.

PubMed

Nelson, G N; Roh, J D; Mirensky, T L; Wang, Y; Yi, T; Tellides, G; Pober, J S; Shkarin, P; Shapiro, E M; Saltzman, W M; Papademetris, X; Fahmy, T M; Breuer, C K

2008-11-01

This pilot study examines noninvasive MR monitoring of tissue-engineered vascular grafts (TEVGs) in vivo using cells labeled with iron oxide nanoparticles. Human aortic smooth muscle cells (hASMCs) were labeled with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles. The labeled hASMCs, along with human aortic endothelial cells, were incorporated into eight TEVGs and were then surgically implanted as aortic interposition grafts in a C.B-17 SCID/bg mouse host. USPIO-labeled hASMCs persisted in the grafts throughout a 3 wk observation period and allowed noninvasive MR imaging of the human TEVGs for real-time, serial monitoring of hASMC retention. This study demonstrates the feasibility of applying noninvasive imaging techniques for evaluation of in vivo TEVG performance.

Electrophysiologic and functional evaluations of regenerated facial nerve defects with a tube containing dental pulp cells in rats.

PubMed

Sasaki, Ryo; Matsumine, Hajime; Watanabe, Yorikatsu; Takeuchi, Yuichi; Yamato, Masayuki; Okano, Teruo; Miyata, Mariko; Ando, Tomohiro

2014-11-01

Dental pulp tissue contains Schwann and neural progenitor cells. Tissue-engineered nerve conduits with dental pulp cells promote facial nerve regeneration in rats. However, no nerve functional or electrophysiologic evaluations were performed. This study investigated the compound muscle action potential recordings and facial functional analysis of dental pulp cell regenerated nerve in rats. A silicone tube containing rat dental pulp cells in type I collagen gel was transplanted into a 7-mm gap of the buccal branch of the facial nerve in Lewis rats; the same defect was created in the marginal mandibular branch, which was ligatured. Compound muscle action potential recordings of vibrissal muscles and facial functional analysis with facial palsy score of the nerve were performed. Tubulation with dental pulp cells showed significantly lower facial palsy scores than the autograft group between 3 and 10 weeks postoperatively. However, the dental pulp cell facial palsy scores showed no significant difference from those of autograft after 11 weeks. Amplitude and duration of compound muscle action potentials in the dental pulp cell group showed no significant difference from those of the intact and autograft groups, and there was no significant difference in the latency of compound muscle action potentials between the groups at 13 weeks postoperatively. However, the latency in the dental pulp cell group was prolonged more than that of the intact group. Tubulation with dental pulp cells could recover facial nerve defects functionally and electrophysiologically, and the recovery became comparable to that of nerve autografting in rats.

Determination of unique power conversion efficiency of solar cell showing hysteresis in the I-V curve under various light intensities.

PubMed

Cojocaru, Ludmila; Uchida, Satoshi; Tamaki, Koichi; Jayaweera, Piyankarage V V; Kaneko, Shoji; Nakazaki, Jotaro; Kubo, Takaya; Segawa, Hiroshi

2017-09-18

Energy harvesting at low light intensities has recently attracted a great deal of attention of perovskite solar cells (PSCs) which are regarded as promising candidate for indoor application. Anomalous hysteresis of the PSCs a complex issue for reliable evaluation of the cell performance. In order to address these challenges, we constructed two new evaluation methods to determinate the power conversion efficiencies (PCEs) of PSCs. The first setup is a solar simulator based on light emitting diodes (LEDs) allowing evaluation of the solar cells at wider range of light intensities, ranging from 10 2  to 10 -3  mW·cm -2 . As the overestimate error, we found that the PCEs of dye sensitized solar cell (DSC) and PSCs increase dramatically at low light intensities conditions. Due to the internal capacitance at the interfaces on hybrid solar cells, the measurement of current below 10 -2  mW·cm -2 shows constant value given high PCE, which is related to the capacitive current and origin of the hysteresis. The second setup is a photovoltaic power analyzing system, designed for tracking the maximum power (P max ) with time. The paper suggests the combination of the LED solar simulator and P max tracking technique as a standard to evaluate the PCE of capacitive solar cells.

NHS-based Tandem Mass Tagging of Proteins at the Level of Whole Cells: A Critical Evaluation in Comparison to Conventional TMT-Labeling Approaches for Quantitative Proteome Analysis.

PubMed

Megger, Dominik A; Pott, Leona L; Rosowski, Kristin; Zülch, Birgit; Tautges, Stephanie; Bracht, Thilo; Sitek, Barbara

2017-01-01

Tandem mass tags (TMT) are usually introduced at the levels of isolated proteins or peptides. Here, for the first time, we report the labeling of whole cells and a critical evaluation of its performance in comparison to conventional labeling approaches. The obtained results indicated that TMT protein labeling using intact cells is generally possible, if it is coupled to a subsequent enrichment using anti-TMT antibody. The quantitative results were similar to those obtained after labeling of isolated proteins and both were found to be slightly complementary to peptide labeling. Furthermore, when using NHS-based TMT, no specificity towards cell surface proteins was observed in the case of cell labeling. In summary, the conducted study revealed first evidence for the general possibility of TMT cell labeling and highlighted limitations of NHS-based labeling reagents. Future studies should therefore focus on the synthesis and investigation of membrane impermeable TMTs to increase specificity towards cell surface proteins.

Illuminating Cell Signaling: Using "Vibrio harveyi" in an Introductory Biology Laboratory

ERIC Educational Resources Information Center

Hrizo, Stacy L.; Kaufmann, Nancy

2009-01-01

Cell signaling is an essential cellular process that is performed by all living organisms. Bacteria communicate with each other using a chemical language in a signaling pathway that allows bacteria to evaluate the size of their population, determine when they have reached a critical mass (quorum sensing), and then change their behavior in unison…

Nickel cadmium cell designs negative to positive material ratio and precharge levels

NASA Technical Reports Server (NTRS)

Gross, S.

1977-01-01

A review is made of the factors affecting the choices of negative-to-positive materials ratio and negative precharge in nickel-cadmium cells. The effects of these variables on performance are given, and the different methods for setting precharge are evaluated. The effects of special operating requirements on the design are also discussed.

SMS/GOES cell and battery data analysis report

NASA Technical Reports Server (NTRS)

Armantrout, J. D.

1977-01-01

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.

Voxel-wise prostate cell density prediction using multiparametric magnetic resonance imaging and machine learning.

PubMed

Sun, Yu; Reynolds, Hayley M; Wraith, Darren; Williams, Scott; Finnegan, Mary E; Mitchell, Catherine; Murphy, Declan; Haworth, Annette

2018-04-26

There are currently no methods to estimate cell density in the prostate. This study aimed to develop predictive models to estimate prostate cell density from multiparametric magnetic resonance imaging (mpMRI) data at a voxel level using machine learning techniques. In vivo mpMRI data were collected from 30 patients before radical prostatectomy. Sequences included T2-weighted imaging, diffusion-weighted imaging and dynamic contrast-enhanced imaging. Ground truth cell density maps were computed from histology and co-registered with mpMRI. Feature extraction and selection were performed on mpMRI data. Final models were fitted using three regression algorithms including multivariate adaptive regression spline (MARS), polynomial regression (PR) and generalised additive model (GAM). Model parameters were optimised using leave-one-out cross-validation on the training data and model performance was evaluated on test data using root mean square error (RMSE) measurements. Predictive models to estimate voxel-wise prostate cell density were successfully trained and tested using the three algorithms. The best model (GAM) achieved a RMSE of 1.06 (± 0.06) × 10 3 cells/mm 2 and a relative deviation of 13.3 ± 0.8%. Prostate cell density can be quantitatively estimated non-invasively from mpMRI data using high-quality co-registered data at a voxel level. These cell density predictions could be used for tissue classification, treatment response evaluation and personalised radiotherapy.

Performance of serum-free broth media for growth of Renibacterium salmoninarum

USGS Publications Warehouse

Starliper, C.E.; Schill, W.B.; Mathias, J.

1998-01-01

Growth of Renibacterium salmoninarum was compared in 14 different broth media; 13 serum-free, and 1 that contained newborn calf serum, KDM2+M. Supplementation with 1% v/v R. salmoninarum MCO4M metabolite was evaluated for 6 of the media that do not utilize it as part of their ingredients. Viable cells were enumerated on Days 10, 20, and 30 post inoculation to evaluate performance. The experiment was repeated 3 times using high, low, and medium (trials 1 to 3, respectively) cell concentrations as inoculum. In general there was no optimal medium and all performed well. The choice of which to employ depends on the ease of preparation and presence of certain ingredients that might affect subsequent assays. In trials 2 and 3, the pH was estimated using test papers at the same time as cells were counted. Maximum pH increase occurred with KDM2+M and those media containing charcoal. For most media, a simple pH determination could be used as a means to check that growth has occurred in a culture, particularly if charcoal was added directly to the media and a visual inspection could not be made to detect growth.

A PDMS Device Coupled with Culture Dish for In Vitro Cell Migration Assay.

PubMed

Lv, Xiaoqing; Geng, Zhaoxin; Fan, Zhiyuan; Wang, Shicai; Pei, WeiHua; Chen, Hongda

2018-04-30

Cell migration and invasion are important factors during tumor progression and metastasis. Wound-healing assay and the Boyden chamber assay are efficient tools to investigate tumor development because both of them could be applied to measure cell migration rate. Therefore, a simple and integrated polydimethylsiloxane (PDMS) device was developed for cell migration assay, which could perform quantitative evaluation of cell migration behaviors, especially for the wound-healing assay. The integrated device was composed of three units, which included cell culture dish, PDMS chamber, and wound generation mold. The PDMS chamber was integrated with cell culture chamber and could perform six experiments under different conditions of stimuli simultaneously. To verify the function of this device, it was utilized to explore the tumor cell migration behaviors under different concentrations of fetal bovine serum (FBS) and transforming growth factor (TGF-β) at different time points. This device has the unique capability to create the "wound" area in parallel during cell migration assay and provides a simple and efficient platform for investigating cell migration assay in biomedical application.

Effects of neratinib and combination with irradiation and chemotherapy in head and neck cancer cells.

PubMed

Schneider, S; Thurnher, D; Kadletz, L; Seemann, R; Brunner, M; Kotowski, U; Schmid, R; Lill, C; Heiduschka, G

2016-11-01

Prognosis of patients with head and neck squamous cell carcinoma (HNSCC) is still poor. Novel therapeutic approaches are of great interest to improve the effects of radiochemotherapy. We evaluated the effects of tyrosine kinase inhibitor neratinib on HNSCC cell lines CAL27, SCC25 and FaDu as a single agent and in combination with irradiation and chemotherapy. Effects of neratinib were evaluated in HNSCC cell lines CAL27, SCC25 and FaDu. Effect on cell viability of neratinib and combination with cisplatin and irradiation was measured using CCK-8 assays and clonogenic assays. Western blot analysis was performed to distinguish the effect on epithelial growth factor receptor and HER2 expression. Apoptosis was evaluated by flow cytometry analysis. Growth inhibition was achieved in all cell lines, whereas combination of cisplatin and neratinib showed greater inhibition than each agent alone. Apoptosis was induced in all cell lines. Combination of neratinib with irradiation or cisplatin showed significantly increased apoptosis. In clonogenic assays, significant growth inhibition was observed in all investigated cell lines. Neratinib, as a single agent or in combination with chemo-irradiation, may be a promising treatment option for patients with head and neck cancer. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chemopreventive effect of chalcone derivative, L2H17, in colon cancer development.

PubMed

Xu, Shanmei; Chen, Minxiao; Chen, Wenbo; Hui, Junguo; Ji, Jiansong; Hu, Shuping; Zhou, Jianmin; Wang, Yi; Liang, Guang

2015-11-09

Colon cancer is the third most commonly diagnosed cancer and the second leading cause of cancer mortality worldwide. Chalcone and its derivatives are reported to exhibit anti-cancer effects in several cancer cell lines, including colon cancer cells. In addition, chalcones have advantages such as poor interaction with DNA and low risk of mutagenesity. In our previous study, a group of chalcone derivatives were synthesized and exhibited strong anti-inflammatory activities. In this study, we evaluated the anti-cancer effects of the chalcone derivative, L2H17, in colon cancer cells. The cytotoxicities of L2H17 on various colon cancer cell lines were investigated by MTT and clonogenic assay. Cell cycle and apoptosis analysis were performed to evaluate the molecular mechanism of L2H17-mediated inhibition of tumor growth. Also, scratch wound and matrigel invasion experiments were performed to estimate the cell migration and invasion after L2H17 treatment. Finally, we observed the anti-colon cancer effects of L2H17 in vivo. Our data show that compound L2H17 exhibited selective cytotoxic effect on colon cancer cells, via inducing G0/G1 cell cycle arrest and apoptosis in CT26.WT cells. Furthermore, L2H17 treatment decreased cell migration and invasion of CT26.WT cells. In addition, L2H17 possessed marked anti-tumor activity in vivo. The molecular mechanism of L2H17-mediated inhibition of tumor promotion and progression were function through inactivated NF-κB and Akt signaling pathways. All these findings show that L2H17 might be a potential growth inhibitory chalcones derivative for colon cancer cells.

[Fabry nephropathy in a female with superposed IgA glomerulonephritis].

PubMed

Pisani, A; Sessa, A; Sabbatini, M; Andreucci, M V; Fusco, C; Balletta, M; Cianciaruso, B

2005-01-01

In Anderson-Fabry disease (AFd), the kidney is affected in all hemizygous males and in some heterozygous females. Female carriers can present subtle renal abnormalities due to glycosphingolipid (GSL) accumulation within renal cells. Renal biopsy is rarely performed in female Fabry patients because clinical renal manifestations are usually lacking. However, female carriers can accumulate GSL in their renal cells despite the absence of clinically evident kidney disease. We performed a kidney biopsy in a 52-year-old female patient, a Fabry disease carrier. The patient showed normal glomerular filtration rate, persistent microhematuria and proteinuria (about 1.7 g/24 hr), cornea "verticillata", and evident left ventricular hypertrophy. The molecular study documented a missense mutation R227Q in exon 5 of the alpha-galactosidase A gene. Optical microscopy showed electron-dense mesangial deposits due IgA glomerulonephritis, as confirmed by immunofluorescence. We decided to start therapy with angiotensin-converting enzyme inhibitors (ACE-I). After 8 months of treatment, the patient demonstrated proteinuria of 0.9 g/24 hr. To decide when to start treatment using enzyme replacement therapy (ERT) with human recombinant GAL A (Fabrazyme), we decided to perform an electron microscopy study of the renal biopsy. The renal ultrastructural findings were typical GSL inclusions in all kinds of glomerular cells, in tubular epithelial cells and in endothelial cells of interstitial capillaries, confirming the hypothesis of Fabry nephropathy. Consequently, Fabrazyme was given at a standard dose of 1 mg/kg every 2 weeks. After 24 months of combined treatment (ACE-I-Fabrazyme), proteinuria decreased to 0.2 g/24 hr. The importance of performing the ultrastructural examination of the kidney biopsy is stressed, especially in heterozygous Fabry patients to evaluate the need to treat them with ERT and to evaluate the degree of renal involvement.

Characterization of Lactic Acid Bacteria as Poultry Probiotic Candidates with Aflatoxin B1 Binding Activities

NASA Astrophysics Data System (ADS)

Damayanti, E.; Istiqomah, L.; Saragih, J. E.; Purwoko, T.; Sardjono

2017-12-01

Our previous studies have selected lactic acid bacteria (LAB) with antifungal activities from traditional fermented foods made from cassava (G7) and silage feed palm leaf (PDS5 and PDS3). In this study we evaluated their ability to bind aflatoxin B1 (AFB1) and probiotic characteristic. The probiotic characteristic assays of LAB consisted of resistance to acidic conditions (pH 3), gastric juice and bile salts 0.3%. We also carried out an in vitro evaluation of LAB aflatoxin binding ability in viable and non-viable cell for 24 and 48 hours of incubation. The measurement of aflatoxin content was performed by ELISA method using AgraQuant Total Aflatoxin Assay kit. The results showed that all isolates were potential as probiotics and the G7 isolate had the highest viability among other isolates in pH 3 (92.61 %) and the bile salts assay (97.71 %). The percentage of aflatoxin reduction between viable and non-viable cell from each LAB isolate were different. The highest aflatoxin reduction in viable cell assay was performed by G7 isolate (69.11 %) whereas in non-viable cell assay was performed by PDS3 isolate (73.75 %) during incubation time 48 hours. In this study, G7 isolate performed the best probiotic characteristics with the highest viability in acid pH assay, bile salt 0.3% assay and percentage of aflatoxin B1 reduction in viable cell condition. Molecular identification using 16S rRNA sequence analysis showed that G7 isolate had homology with Lactobacillus plantarum (99.9%). It was concluded that Lactobacillus plantarum G7 was potential as probiotic with aflatoxin binding activities.

Geophysical background and as-built target characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, J.W.

1994-09-01

The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) has provided a facility for DOE, other Government agencies, and the private sector to evaluate and document the utility of specific geophysical measurement techniques for detecting and defining cultural and environmental targets. This facility is the Rabbit Valley Geophysics Performance Evaluation Range (GPER). Geophysical surveys prior to the fiscal year (FY) 1994 construction of new test cells showed the primary test area to be relatively homogeneous and free from natural or man-made artifacts, which would generate spurious responses in performance evaluation data. Construction of nine new cell areas inmore » Rabbit Valley was completed in June 1994 and resulted in the emplacement of approximately 150 discrete targets selected for their physical and electrical properties. These targets and their geophysical environment provide a broad range of performance evaluation parameters from ``very easy to detect`` to ``challenging to the most advanced systems.`` Use of nonintrusive investigative techniques represents a significant improvement over intrusive characterization methods, such as drilling or excavation, because there is no danger of exposing personnel to possible hazardous materials and no risk of releasing or spreading contamination through the characterization activity. Nonintrusive geophysical techniques provide the ability to infer near-surface structure and waste characteristics from measurements of physical properties associated with those targets.« less

Comparison of segmentation algorithms for fluorescence microscopy images of cells.

PubMed

Dima, Alden A; Elliott, John T; Filliben, James J; Halter, Michael; Peskin, Adele; Bernal, Javier; Kociolek, Marcin; Brady, Mary C; Tang, Hai C; Plant, Anne L

2011-07-01

The analysis of fluorescence microscopy of cells often requires the determination of cell edges. This is typically done using segmentation techniques that separate the cell objects in an image from the surrounding background. This study compares segmentation results from nine different segmentation techniques applied to two different cell lines and five different sets of imaging conditions. Significant variability in the results of segmentation was observed that was due solely to differences in imaging conditions or applications of different algorithms. We quantified and compared the results with a novel bivariate similarity index metric that evaluates the degree of underestimating or overestimating a cell object. The results show that commonly used threshold-based segmentation techniques are less accurate than k-means clustering with multiple clusters. Segmentation accuracy varies with imaging conditions that determine the sharpness of cell edges and with geometric features of a cell. Based on this observation, we propose a method that quantifies cell edge character to provide an estimate of how accurately an algorithm will perform. The results of this study will assist the development of criteria for evaluating interlaboratory comparability. Published 2011 Wiley-Liss, Inc.

Impaired Akt phosphorylation in B-cells of patients with common variable immunodeficiency.

PubMed

Yazdani, Reza; Ganjalikhani-Hakemi, Mazdak; Esmaeili, Mohammad; Abolhassani, Hassan; Vaeli, Shahram; Rezaei, Abbas; Sharifi, Zohre; Azizi, Gholamreza; Rezaei, Nima; Aghamohammadi, Asghar

2017-02-01

Common variable immunodeficiency (CVID) is a heterogeneous group of primary immunodeficiency characterized by recurrent infections. We evaluated whether defective PI3K/Akt/FoxO pathway could influence B-cell fate. Determination of B-cell subsets in CVD patients and healthy donors (HDs) were performed using flow cytometry. We evaluated mRNA and protein expression of PI3K, Akt and FoxO using real-time PCR and flow cytometry, respectively. Moreover, phosphorylated Akt (pAkt) expression in B-cells has been measured by flowcytometry. We identified a significant reduction in the percentage of marginal zone like B-cells, memory B-cells (total, switched and unswitched) and plasmablasts in patients, as these decreased B-cell subsets had a significant negative correlation with increased apoptosis in patients. Surprisingly, we identified decreased pAkt expression in B-cells of patients than HDs. We described for the first time impaired pAkt expression in B-cells of CVID patients that had a significant correlation with antibody response to the vaccine and worse clinical complications. Copyright © 2016 Elsevier Inc. All rights reserved.

Further Analyses of the NASA Glenn Research Center Solar Cell and Photovoltaic Materials Experiment Onboard the International Space Station

NASA Technical Reports Server (NTRS)

Myers, Matthew G.; Prokop, Norman F.; Krasowski, Michael J.; Piszczor, Michael F.; McNatt, Jeremiah S.

2016-01-01

Accurate air mass zero (AM0) measurement is essential for the evaluation of new photovoltaic (PV) technology for space solar cells. The NASA Glenn Research Center (GRC) has flown an experiment designed to measure the electrical performance of several solar cells onboard NASA Goddard Space Flight Center's (GSFC) Robotic Refueling Mission's (RRM) Task Board 4 (TB4) on the exterior of the International Space Station (ISS). Four industry and government partners provided advanced PV devices for measurement and orbital environment testing. The experiment was positioned on the exterior of the station for approximately eight months, and was completely self-contained, providing its own power and internal data storage. Several new cell technologies including four-junction (4J) Inverted Metamorphic Multi-Junction (IMM) cells were evaluated and the results will be compared to ground-based measurement methods.

Erythrocyte depletion from bone marrow: performance evaluation after 50 clinical-scale depletions with Spectra Optia BMC.

PubMed

Kim-Wanner, Soo-Zin; Bug, Gesine; Steinmann, Juliane; Ajib, Salem; Sorg, Nadine; Poppe, Carolin; Bunos, Milica; Wingenfeld, Eva; Hümmer, Christiane; Luxembourg, Beate; Seifried, Erhard; Bonig, Halvard

2017-08-11

Red blood cell (RBC) depletion is a standard graft manipulation technique for ABO-incompatible bone marrow (BM) transplants. The BM processing module for Spectra Optia, "BMC", was previously introduced. We here report the largest series to date of routine quality data after performing 50 clinical-scale RBC-depletions. Fifty successive RBC-depletions from autologous (n = 5) and allogeneic (n = 45) BM transplants were performed with the Spectra Optia BMC apheresis suite. Product quality was assessed before and after processing for volume, RBC and leukocyte content; RBC-depletion and stem cell (CD34+ cells) recovery was calculated there from. Clinical engraftment data were collected from 26/45 allogeneic recipients. Median RBC removal was 98.2% (range 90.8-99.1%), median CD34+ cell recovery was 93.6%, minimum recovery being 72%, total product volume was reduced to 7.5% (range 4.7-23.0%). Products engrafted with expected probability and kinetics. Performance indicators were stable over time. Spectra Optia BMC is a robust and efficient technology for RBC-depletion and volume reduction of BM, providing near-complete RBC removal and excellent CD34+ cell recovery.

Analysis and performance assessment of a new solar-based multigeneration system integrated with ammonia fuel cell and solid oxide fuel cell-gas turbine combined cycle

NASA Astrophysics Data System (ADS)

Siddiqui, Osamah; Dincer, Ibrahim

2017-12-01

In the present study, a new solar-based multigeneration system integrated with an ammonia fuel cell and solid oxide fuel cell-gas turbine combined cycle to produce electricity, hydrogen, cooling and hot water is developed for analysis and performance assessment. In this regard, thermodynamic analyses and modeling through both energy and exergy approaches are employed to assess and evaluate the overall system performance. Various parametric studies are conducted to study the effects of varying system parameters and operating conditions on the energy and exergy efficiencies. The results of this study show that the overall multigeneration system energy efficiency is obtained as 39.1% while the overall system exergy efficiency is calculated as 38.7%, respectively. The performance of this multigeneration system results in an increase of 19.3% in energy efficiency as compared to single generation system. Furthermore, the exergy efficiency of the multigeneration system is 17.8% higher than the single generation system. Moreover, both energy and exergy efficiencies of the solid oxide fuel cell-gas turbine combined cycle are determined as 68.5% and 55.9% respectively.

Is atypical squamous cells that cannot exclude high-grade squamous intraepithelial lesion clinically significant?

PubMed

McHale, Michael T; Souther, Jessica; Elkas, John C; Monk, Bradley J; Harrison, Terry A

2007-04-01

To determine the cumulative risk of cervical intraepithelial neoplasia (CIN) 2 or 3 in patients with atypical squamous cells, cannot exclude HSIL (ASC-H). A retrospective analysis was performed to identify patients referred to the dysplasia clinic with ASC-H. Initial evaluation included colposcopy, endocervical curettage, and an ectocervical biopsy, when indicated, in all the patients. A follow-up evaluation was performed at 6 and 12 months. Cumulative histological diagnosis of CIN 2 or 3 at 12 months served as the clinical end point. Two hundred twenty-nine patients with ASC-H and with a mean age of 32.8 years were evaluated. At the time of initial colposcopy, only 10.0% (23/229; 95% CI = 6.5%-15%) of the patients had histological evidence of CIN 2 or 3. The cumulative risk of CIN 2 or 3 was 12.2% (95% CI = 8%-17%). Evaluation of patients with ASC-H with colposcopy does lead to the detection of CIN 2 or 3 but perhaps at a rate lower than previously reported.

Development of a high efficiency thin silicon solar cell. [fabrication and stability tests

NASA Technical Reports Server (NTRS)

Lindmayer, J.

1976-01-01

One hundred thin (120 microns to 260 microns) silicon-aluminum solar cells were fabricated and tested. Silicon slices were prepared, into which an aluminum alloy was evaporated over a range of temperatures and times. Antireflection coatings of tantalum oxide were applied to the cells. Reflectance of the silicon-aluminum interfaces was correlated to alloy temperature (graphs are shown). Optical measurements of the rear surface-internal reflectance of the cells were performed using a Beckman spectrophotometer. An improved gridline pattern was evaluated and stability tests (thermal cycling tests) were performed. Results show that: (1) a high-index, high-transmittance antireflection coating was obtained; (2) the improved metallization of the cells gave a 60 percent rear surface-internal reflectance, and the cells displayed excellent fill factors and blue response of the spectrum; (3) an improved gridline pattern (5 micron linewidths compared to 13 micron linewidths) resulted in a 1.3 percent improvement in short circuit currents; and (4) the stability tests showed no change in cell properties.

Regeneration of skin tissue promoted by mesenchymal stem cells seeded in nanostructured membrane.

PubMed

Souza, C M C O; Mesquita, L A F; Souza, D; Irioda, A C; Francisco, J C; Souza, C F; Guarita-Souza, L C; Sierakowski, M-R; Carvalho, K A T

2014-01-01

The mesenchymal stem cell therapy has proven to be an effective option in the treatment of skin injuries. The combination of these cells with nanostructured membranes seems to be the future for tissues recovery. The aim of this project was to use biomolecules of polysaccharides to be incorporated on regenerated cellulose membranes and to prospect the improvement as bioactive wound dressings with mesenchymal stem cells. The biocomposites were obtained after defibrillation with the use of never-dried bacterial cellulose to form a pulp, and, after the films were regenerated, in the presence of gellan gum with or without fluconazole. Membrane atomic force microscopy was performed for comparison of their structures. Adipose-derived mesenchymal stem cells were obtained from human adipose tissue liposuction in accordance with Zuk et al. The flow cytometric analysis and induction tests for adipocytes and osteocytes were performed. In vitro assays were performed on different membranes to evaluate the ability of these cells to adhere at 2 hours and proliferate at 7 days; the results were obtained by use of the MTT cell counting technique. In vivo testing allowed us to observe cell migration and participation in wound-healing by fluorescence labeling of the cells with BrdU. The bioactive curative, seeded with cells, was tested in skin burned in a murine model. The bacterial cellulose with gelan gum membrane incorporated with fluconazole presented the best performance in adhesion and proliferation tests. The cells can be identified in burned host tissue after occurrence of the wound. Copyright © 2014 Elsevier Inc. All rights reserved.

A Multicenter Study To Evaluate the Performance of High-Throughput Sequencing for Virus Detection

PubMed Central

Ng, Siemon H. S.; Vandeputte, Olivier; Aljanahi, Aisha; Deyati, Avisek; Cassart, Jean-Pol; Charlebois, Robert L.; Taliaferro, Lanyn P.

2017-01-01

ABSTRACT The capability of high-throughput sequencing (HTS) for detection of known and unknown viruses makes it a powerful tool for broad microbial investigations, such as evaluation of novel cell substrates that may be used for the development of new biological products. However, like any new assay, regulatory applications of HTS need method standardization. Therefore, our three laboratories initiated a study to evaluate performance of HTS for potential detection of viral adventitious agents by spiking model viruses in different cellular matrices to mimic putative materials for manufacturing of biologics. Four model viruses were selected based upon different physical and biochemical properties and commercial availability: human respiratory syncytial virus (RSV), Epstein-Barr virus (EBV), feline leukemia virus (FeLV), and human reovirus (REO). Additionally, porcine circovirus (PCV) was tested by one laboratory. Independent samples were prepared for HTS by spiking intact viruses or extracted viral nucleic acids, singly or mixed, into different HeLa cell matrices (resuspended whole cells, cell lysate, or total cellular RNA). Data were obtained using different sequencing platforms (Roche 454, Illumina HiSeq1500 or HiSeq2500). Bioinformatic analyses were performed independently by each laboratory using available tools, pipelines, and databases. The results showed that comparable virus detection was obtained in the three laboratories regardless of sample processing, library preparation, sequencing platform, and bioinformatic analysis: between 0.1 and 3 viral genome copies per cell were detected for all of the model viruses used. This study highlights the potential for using HTS for sensitive detection of adventitious viruses in complex biological samples containing cellular background. IMPORTANCE Recent high-throughput sequencing (HTS) investigations have resulted in unexpected discoveries of known and novel viruses in a variety of sample types, including research materials, clinical materials, and biological products. Therefore, HTS can be a powerful tool for supplementing current methods for demonstrating the absence of adventitious or unwanted viruses in biological products, particularly when using a new cell line. However, HTS is a complex technology with different platforms, which needs standardization for evaluation of biologics. This collaborative study was undertaken to investigate detection of different virus types using two different HTS platforms. The results of the independently performed studies demonstrated a similar sensitivity of virus detection, regardless of the different sample preparation and processing procedures and bioinformatic analyses done in the three laboratories. Comparable HTS detection of different virus types supports future development of reference virus materials for standardization and validation of different HTS platforms. PMID:28932815

Dental pulp pluripotent-like stem cells (DPPSC), a new stem cell population with chromosomal stability and osteogenic capacity for biomaterials evaluation.

PubMed

Núñez-Toldrà, Raquel; Martínez-Sarrà, Ester; Gil-Recio, Carlos; Carrasco, Miguel Ángel; Al Madhoun, Ashraf; Montori, Sheyla; Atari, Maher

2017-04-21

Biomaterials are widely used to regenerate or substitute bone tissue. In order to evaluate their potential use for clinical applications, these need to be tested and evaluated in vitro with cell culture models. Frequently, immortalized osteoblastic cell lines are used in these studies. However, their uncontrolled proliferation rate, phenotypic changes or aberrations in mitotic processes limits their use in long-term investigations. Recently, we described a new pluripotent-like subpopulation of dental pulp stem cells derived from the third molars (DPPSC) that shows genetic stability and shares some pluripotent characteristics with embryonic stem cells. In this study we aim to describe the use of DPPSC to test biomaterials, since we believe that the biomaterial cues will be more critical in order to enhance the differentiation of pluripotent stem cells. The capacity of DPPSC to differentiate into osteogenic lineage was compared with human sarcoma osteogenic cell line (SAOS-2). Collagen and titanium were used to assess the cell behavior in commonly used biomaterials. The analyses were performed by flow cytometry, alkaline phosphatase and mineralization stains, RT-PCR, immunohistochemistry, scanning electron microscopy, Western blot and enzymatic activity. Moreover, the genetic stability was evaluated and compared before and after differentiation by short-comparative genomic hybridization (sCGH). DPPSC showed excellent differentiation into osteogenic lineages expressing bone-related markers similar to SAOS-2. When cells were cultured on biomaterials, DPPSC showed higher initial adhesion levels. Nevertheless, their osteogenic differentiation showed similar trend among both cell types. Interestingly, only DPPSC maintained a normal chromosomal dosage before and after differentiation on 2D monolayer and on biomaterials. Taken together, these results promote the use of DPPSC as a new pluripotent-like cell model to evaluate the biocompatibility and the differentiation capacity of biomaterials used in bone regeneration.

Enhancement of photovoltaic cell performance using periodic triangular gratings

NASA Astrophysics Data System (ADS)

Bordatchev, Evgueni; Tauhiduzzaman, Mohammed; Dey, Rajat

2014-01-01

The solar energy industry strives to produce more efficient and yet cost effective solar panels each consisting of an array of photovoltaic (PV) cells. The goal of this study was to enhance the performance of PV cells through increasing the cells' optical efficiency defined as a percentage of surface incident light that reaches the PV material. This was achieved through the reduction of waveguide decoupling loss and Fresnel reflection losses by integrating specific nonimaging micro-optical structures on the top surface of existing PV cells. Due to this integration, optical efficiency and performance were increased through the enhancement of light trapping, light guiding, and in-coupling functionalities. Periodic triangular gratings (PTGs) were designed, nonsequentially modeled, optimized, and fabricated in polydimethylsiloxane as proposed micro-optical structures. Then the performance of PV cells with and without integrated PTGs was evaluated and compared. Initial optical simulation results show that an original PV cell (without PTG) exhibits an average optical efficiency of 32.7% over a range of incident light angles between 15 and 90 deg. Integration of the PTG allows the capture of incoming sunlight by total internal reflection (TIR), whence it is reflected back onto the PV cell for multiple consecutive chances for absorption and PV conversion. Geometry of the PTG was optimized with respect to an angle of light incidence of {15, 30, 45, 60, 75, 90} deg. Optical efficiency of the geometrically optimized PTGs was then analyzed under the same set of incident light angles and a maximum optical efficiency of 54.1% was observed for a PV cell with integrated PTG optimized at 90 deg. This is a 53.3% relative improvement in optical performance when compared to an original PV cell. Functional PTG prototypes were then fabricated with optical surface quality (below 10 nm Ra) and integrated with PV cells demonstrating an increase in maximum power by 1.08 mW/cm (7.6% improvement in PV performance) and in short circuit current by 2.39 mA/cm (6.4% improvement).

On-Orbit Measurement of Next Generation Space Solar Cell Technology on the International Space Station

NASA Technical Reports Server (NTRS)

Wolford, David S.; Myers, Matthew G.; Prokop, Norman F.; Krasowski, Michael J.; Parker, David S.; Cassidy, Justin C.; Davies, William E.; Vorreiter, Janelle O.; Piszczor, Michael F.; McNatt, Jeremiah S.

2014-01-01

On-orbit measurements of new photovoltaic (PV) technologies for space power are an essential step in the development and qualification of advanced solar cells. NASA Glenn Research Center will fly and measure several solar cells attached to NASA Goddards Robotic Refueling Mission (RRM), expected to be launched in 2014. Industry and government partners have provided advanced PV devices for evaluation of performance and environmental durability. The experiment is completely self-contained, providing its own power and internal data storage. Several new cell technologies including Inverted Metamorphic Multi-junction and four-junction cells will be tested.

Gravity dependent processes and intracellular motion

NASA Technical Reports Server (NTRS)

Todd, Paul

1991-01-01

Most organelles large enough to sediment or to undergo isothermal settling within eukaryotic cells are held in position by one or more components of the cytoskeleton. The interior of eukaryotic cells is considered to be very crowded, and the evaluation of natural-convective processes is very difficult. In a most simple view, the cell may be considered as consisting of four immiscible phases among which solutes are exchanged causing steep concentration gradients and thermodynamic conditions far from equilibrium. Extracellular gravity-related forces may include natural convection due to solute gradients external to single cells or the work performed by swimming, ciliated, or elongating cells.

In vivo and in vitro evaluation of an Acetobacter xylinum synthesized microbial cellulose membrane intended for guided tissue repair

PubMed Central

Mendes, Péricles Nóbrega; Rahal, Sheila Canevese; Pereira-Junior, Oduvaldo Câmara Marques; Fabris, Viciany Erique; Lenharo, Sara Lais Rahal; de Lima-Neto, João Ferreira; da Cruz Landim-Alvarenga, Fernanda

2009-01-01

Background Barrier materials as cellulose membranes are used for guided tissue repair. However, it is essential that the surrounding tissues accept the device. The present study histologically evaluated tissue reaction to a microbial cellulose membrane after subcutaneous implantation in mice. Furthermore, the interaction between mesenchymal stem cells and the biomaterial was studied in vitro to evaluate its ability to act as cellular scaffold for tissue engineering. Methods Twenty-five Swiss Albino mice were used. A 10 × 10 mm cellulose membrane obtained through biosynthesis using Acetobacter xylinum bacteria was implanted into the lumbar subcutaneous tissue of each mouse. The mice were euthanatized at seven, 15, 30, 60, and 90 days, and the membrane and surrounding tissues were collected and examined by histology. Results A mild inflammatory response without foreign body reaction was observed until 30 days post-surgery around the implanted membrane. Polarized microscopy revealed that the membrane remained intact at all evaluation points. Scanning electron microscopy of the cellulose membrane surface showed absence of pores. The in vitro evaluation of the interaction between cells and biomaterial was performed through viability staining analysis of the cells over the biomaterial, which showed that 95% of the mesenchymal stem cells aggregating to the cellulose membrane were alive and that 5% were necrotic. Scanning electron microscopy showed mesenchymal stem cells with normal morphology and attached to the cellulose membrane surface. Conclusion The microbial cellulose membrane evaluated was found to be nonresorbable, induced a mild inflammatory response and may prove useful as a scaffold for mesenchymal stem cells. PMID:19317903

Fabrication and characterization of solid oxide cells for energy conversion and storage

NASA Astrophysics Data System (ADS)

Yang, Chenghao

2011-12-01

There has been an increasing interest in clean and renewable energy generation for highlighted energy and environmental concerns. Solid oxide cells (SOCs) have been considered as one of the promising technologies, since they can be operated efficiently both in electrolysis mode by generating hydrogen through steam electrolysis and fuel cell mode by electrochemically combining fuel with oxidant. The present work is devoted to performing a fundamental study of SOC in both fuel cell mode for power generation and electrolysis mode for fuel production. The research work on SOCs that can be operated reversibly for power generation and fuel production has been conducted in the following six projects: (1) High performance solid oxide electrolysis cell (SOEC) Fabrication of novel structured SOEC oxygen electrode with the conventional and commercial solid oxide fuel cell materials by screen-printing and infiltration fabrication methods. The microstructure, electrochemical properties and durability of SOECs has been investigated. It was found that the LSM infiltrated cell has an area specific resistance (ASR) of 0.20 Ω cm2 at 900°C at open circuit voltage with 50% absolute humidity (AH), which is relatively lower than that of the cell with LSM-YSZ oxygen electrode made by a conventional mixing method. Electrolysis cell with LSM infiltrated oxygen electrode has demonstrated stable performance under electrolysis operation with 0.33 A/cm2 and 50 vol.% AH at 800°C. (2) Advanced performance high temperature micro-tubular solid oxide fuel cell (MT-SOFC) Phase-inversion, dip-coating, high temperature co-sintering process and impregnation method were used to fabricate micro-tubular solid oxide fuel cell. The micro-structure of the micro-tubular fuel cell will be investigated and the power output and thermal robustness has been evaluated. High performance and rapid start-up behavior have been achieved, indicates that the MT-SOFC developed in this work can be a promising technology for portable applications. (3) Promising intermediate temperature micro-tubular solid oxide fuel cells for portable power supply applications Maximum power densities of 0.5, 0.38 and 0.27 W/cm2 have been obtained using H2-15% H2O as fuel at 550, 600 and 650°C, respectively. Quick thermal cycles performed on the intermediate temperature MT-SOFC stability demonstrate that the cell has robust performance stability for portable applications. (4) Micro-tubular solid oxide cell (MT-SOC) for steam electrolysis The electrochemical properties of MT-SOC will be investigated in detail in electrolysis mode. The mechanism of the novel hydrogen electrode structure benefiting the cell performance will be demonstrated systematically. The high electrochemical performance of the MT-SOC in electrolysis mode indicates that MT-SOC can provide an efficient hydrogen generation process. (5) Micro-tubular solid oxide cell (MT-SOC) for steam and CO2 co-electrolysis The MT-SOC will be operated in co-electrolysis mode for steam and CO 2, which will provide an efficient approach to generate syngas (H2+CO) without consuming fossil fuels. This can potentially provide an alternative superior approach for carbon sequestration which has been a critical issue facing the sustainability of our society. (6) Steam and CO2 co-electrolysis using solid oxide cells fabricated by freeze-drying tape-casting Tri-layer scaffolds have been prepared by freeze-drying tape casting process and the electrode catalysts are obtained by infiltrating the porous electrode substrates. Button cells will be tested for co-electrolysis of steam and CO2. The mechanism and efficiency of steam and CO2 co-electrolysis will be systemically investigated. In conclusion, SOCs have been fabricated with conventional materials and evaluated, but their performance has been found to be limited in either SOFC or SOEC mode. The cell performance has been significantly improved by employing an infiltrated LSM-YSZ electrode, due to dramatically decreased polarization resistance. However, mass transport limitation has been observed, particularly in electrolysis mode. By utilizing micro-tubular SOCs with novel hydrogen electrode produced via a phase inversion method, mass transport limitation has been mitigated. Finally, mass transport has been further improved by using cells with electrodes fabricated through a freeze-drying tape-casting method. (Abstract shortened by UMI.)

Technologies for Single-Cell Isolation

PubMed Central

Gross, Andre; Schoendube, Jonas; Zimmermann, Stefan; Steeb, Maximilian; Zengerle, Roland; Koltay, Peter

2015-01-01

The handling of single cells is of great importance in applications such as cell line development or single-cell analysis, e.g., for cancer research or for emerging diagnostic methods. This review provides an overview of technologies that are currently used or in development to isolate single cells for subsequent single-cell analysis. Data from a dedicated online market survey conducted to identify the most relevant technologies, presented here for the first time, shows that FACS (fluorescence activated cell sorting) respectively Flow cytometry (33% usage), laser microdissection (17%), manual cell picking (17%), random seeding/dilution (15%), and microfluidics/lab-on-a-chip devices (12%) are currently the most frequently used technologies. These most prominent technologies are described in detail and key performance factors are discussed. The survey data indicates a further increasing interest in single-cell isolation tools for the coming years. Additionally, a worldwide patent search was performed to screen for emerging technologies that might become relevant in the future. In total 179 patents were found, out of which 25 were evaluated by screening the title and abstract to be relevant to the field. PMID:26213926

Technologies for Single-Cell Isolation.

PubMed

Gross, Andre; Schoendube, Jonas; Zimmermann, Stefan; Steeb, Maximilian; Zengerle, Roland; Koltay, Peter

2015-07-24

The handling of single cells is of great importance in applications such as cell line development or single-cell analysis, e.g., for cancer research or for emerging diagnostic methods. This review provides an overview of technologies that are currently used or in development to isolate single cells for subsequent single-cell analysis. Data from a dedicated online market survey conducted to identify the most relevant technologies, presented here for the first time, shows that FACS (fluorescence activated cell sorting) respectively Flow cytometry (33% usage), laser microdissection (17%), manual cell picking (17%), random seeding/dilution (15%), and microfluidics/lab-on-a-chip devices (12%) are currently the most frequently used technologies. These most prominent technologies are described in detail and key performance factors are discussed. The survey data indicates a further increasing interest in single-cell isolation tools for the coming years. Additionally, a worldwide patent search was performed to screen for emerging technologies that might become relevant in the future. In total 179 patents were found, out of which 25 were evaluated by screening the title and abstract to be relevant to the field.

Bortezomib sensitizes esophageal squamous cancer cells to radiotherapy by suppressing the expression of HIF-1α and apoptosis proteins.

PubMed

Wang, Di; Qin, Qin; Jiang, Qin-Juan; Wang, Da-Fei

2016-04-13

Radiation therapy is a typical treatment for esophageal squamous cell carcinoma (ESCC), especially middle and upper segment esophagus, and inoperable patients. However, how to promote radiation sensitivity in radio-resistant cancer cells is a conundrum. Here, our study investigated the radiosensitizing effect of bortezomib, a specific and reversible dipeptide boronic acid analog, in ESCC cells. Human esophageal squamous carcinoma cell lines Eca109 and TE-13 were exposed to hypoxia and/or ionizing radiation (IR) with or without treatment of bortezomib. Cell proliferation assay was performed with CCK8. Cell apoptosis and cell cycle assay were performed with flow cytometry. The radiosensitization effect of was assessed by clonogenic survival and progression of tumor xenograft. The expression of HIF-1α, VEGF, and apoptosis proteins was evaluated by Western blot. Radiation-induced DNA double strand break and homologous recombination repair were assessed by immunofluorescence. Our results show that bortezomib efficiently radiosensitizes ESCC cells by decreasing the expression of HIF- 1α and VEGF, inducing apoptosis by activating caspase, and delaying DNA damage repair after radiation.

Quantitative Chemical-Genetic Interaction Map Connects Gene Alterations to Drug Responses | Office of Cancer Genomics

Cancer.gov

In a recent Cancer Discovery report, CTD2 researchers at the University of California in San Francisco developed a new quantitative chemical-genetic interaction mapping approach to evaluate drug sensitivity or resistance in isogenic cell lines. Performing a high-throughput screen with isogenic cell lines allowed the researchers to explore the impact of a panel of emerging and established drugs on cells overexpressing a single cancer-associated gene in isolation.

Highly water-dispersible, mixed ionic-electronic conducting, polymer acid-doped polyanilines as ionomers for direct methanol fuel cells.

PubMed

Murthy, Arun; Manthiram, Arumugam

2011-06-28

Highly water-dispersible polymer acid-doped polyanilines have been synthesized and evaluated as an alternative for expensive Nafion ionomers in the anode of direct methanol fuel cells (DMFC). These polymers as ionomers lead to higher performance in single cell DMFC compared to Nafion ionomers due to mixed ionic-electronic conduction, water dispersibility, and co-catalytic activity. This journal is © The Royal Society of Chemistry 2011

Effect of zirconium nitride physical vapor deposition coating on preosteoblast cell adhesion and proliferation onto titanium screws.

PubMed

Rizzi, Manuela; Gatti, Giorgio; Migliario, Mario; Marchese, Leonardo; Rocchetti, Vincenzo; Renò, Filippo

2014-11-01

Titanium has long been used to produce dental implants. Problems related to its manufacturing, casting, welding, and ceramic application for dental prostheses still limit its use, which highlights the need for technologic improvements. The aim of this in vitro study was to evaluate the biologic performance of titanium dental implants coated with zirconium nitride in a murine preosteoblast cellular model. The purpose of this study was to evaluate the chemical and morphologic characteristics of titanium implants coated with zirconium nitride by means of physical vapor deposition. Chemical and morphologic characterizations were performed by scanning electron microscopy and energy dispersive x-ray spectroscopy, and the bioactivity of the implants was evaluated by cell-counting experiments. Scanning electron microscopy and energy dispersive x-ray spectroscopy analysis found that physical vapor deposition was effective in covering titanium surfaces with zirconium nitride. Murine MC-3T3 preosteoblasts were seeded onto titanium-coated and zirconium nitride-coated screws to evaluate their adhesion and proliferation. These experiments found a significantly higher number of cells adhering and spreading onto zirconium nitride-coated surfaces (P<.05) after 24 hours; after 7 days, both titanium and zirconium nitride surfaces were completely covered with MC-3T3 cells. Analysis of these data indicates that the proposed zirconium nitride coating of titanium implants could make the surface of the titanium more bioactive than uncoated titanium surfaces. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Comparative study of a novel application of automated HR HPV assay and stability in a previously untested Preservative media.

PubMed

Morel, Mike E; McBride, Simon E; Gomez, Maria P

2017-12-01

The suitability and stability of cervical cells in Novaprep media (NHQ) for certain HPV assays is unknown. We evaluated the accuracy of an automated HPV assay (Abbott RealTime HR HPV) for cervical cells prepared in NHQ and NHQ with a pre-treatment to mimic a worst case clinical use, compared to the assay manufacturers media; repeatability and reproducibility of HPV results and the stability of detectable HPV in NHQ over time compared to CE marked liquid based cytology preservatives. Cell lines were used to simulate patient samples. Cells stored in NHQ produced accurate, repeatable and reproducible results. Stability in NHQ was comparable to the best performing LBC, with at least 7 months' stability at 18-25°C, 2-8°C, -20°C and -80°C; and at least 3 months' stability at 40°C. Similar results were obtained for pre-treated NHQ except only 3.5 months' stability at 18-25°C. Cell line samples in all media and concentrations tested were detected appropriately by the assay. Based on this first stage validation analytical study, cervical cells stored in NHQ are suitable for the Realtime HPV assay. There should be no reservations for inclusion of NHQ in any further validation and clinical performance evaluation of this assay. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Workers exposed to low levels of benzene present in urban air: Assessment of peripheral blood count variations.

PubMed

Casale, Teodorico; Sacco, Carmina; Ricci, Serafino; Loreti, Beatrice; Pacchiarotti, Alessandro; Cupelli, Vincenzo; Arcangeli, Giulio; Mucci, Nicola; Antuono, Vittorio; De Marco, Federica; Tomei, Gianfranco; Tomei, Francesco; Rosati, Maria Valeria

2016-06-01

Few studies in the literature have examined the effects of benzene on blood cells. The aim of this study was to evaluate the possible correlation between the blood benzene levels and the blood cell counts. From a population of 2658 workers, we studied a group of 215 subjects. Each worker underwent blood sampling for the assessment of the blood benzene levels and the blood cell counts. The Mann-Whitney U test for two-mode variables and the Kruskal-Wallis test for more-than-two-mode variables were performed on all subjects. We estimated the Pearson correlation index between the variables in the total sample and the subgroups divided according to sex, the smoking habit, and job. After the main confounding factors were evaluated, multiple linear regression was performed on both the total sample and the subgroups. A significant inverse correlation was found among the blood benzene levels and the white blood cells, lymphocytes, and neutrophils in traffic policemen, motorcyclists, and other outdoor workers. We did not find any significant correlation with any other parameters of blood cell count. Our results, which must be considered preliminary, indicate that increased blood benzene levels in outdoor workers lead to decreased counts of white blood cells, neutrophils, and lymphocytes, because of possible immune effects. These are worth investigating in the future by specific immune tests. Copyright © 2016. Published by Elsevier Ltd.

Definition study for photovoltaic residential prototype system

NASA Technical Reports Server (NTRS)

Shepard, N. F.; Landes, R.; Kornrumpf, W. P.

1976-01-01

A site evaluation was performed to assess the relative merits of different regions of the country in terms of the suitability for experimental photovoltaic powered residences. Eight sites were selected based on evaluation criteria which included population, photovoltaic systems performance and the cost of electrical energy. A parametric sensitivity analysis was performed for four selected site locations. Analytical models were developed for four different power system implementation approaches. Using the model which represents a direct (or float) charge system implementation the performance sensitivity to the following parameter variations is reported: (1) solar roof slope angle; (2) ratio of the number of series cells in the solar array to the number of series cells in the lead-acid battery; and (3) battery size. For a Cleveland site location, a system with no on site energy storage and with a maximum power tracking inverter which feeds back excess power to the utility was shown to have 19 percent greater net system output than the second place system. The experiment test plan is described. The load control and data acquisition system and the data display panel for the residence are discussed.

Efficient globally optimal segmentation of cells in fluorescence microscopy images using level sets and convex energy functionals.

PubMed

Bergeest, Jan-Philip; Rohr, Karl

2012-10-01

In high-throughput applications, accurate and efficient segmentation of cells in fluorescence microscopy images is of central importance for the quantification of protein expression and the understanding of cell function. We propose an approach for segmenting cell nuclei which is based on active contours using level sets and convex energy functionals. Compared to previous work, our approach determines the global solution. Thus, the approach does not suffer from local minima and the segmentation result does not depend on the initialization. We consider three different well-known energy functionals for active contour-based segmentation and introduce convex formulations of these functionals. We also suggest a numeric approach for efficiently computing the solution. The performance of our approach has been evaluated using fluorescence microscopy images from different experiments comprising different cell types. We have also performed a quantitative comparison with previous segmentation approaches. Copyright © 2012 Elsevier B.V. All rights reserved.

High performance anode-supported tubular solid oxide fuel cells fabricated by a novel slurry-casting method

PubMed Central

Duan, Nan-Qi; Yan, Dong; Chi, Bo; Pu, Jian; Jian, Li

2015-01-01

Tubular solid oxide fuel cells were fabricated and evaluated for their microstructure and electrochemical performance. The tubular substrate was prepared by casting NiO-Y2O3 stabilized ZrO2 (YSZ) slurry on the inner wall of a plastic mold (tube). The wall thickness and uniformity were controlled by slurry viscosity and rotation speed of the tube. The cells consisted of Ni-YSZ functional anode, YSZ electrolyte and (La0.8Sr0.2)0.95MnO3-δ (LSM)-YSZ cathode prepared in sequence on the substrate by dip-coating and sintering. Their dimension was 50 mm in length, 0.8 mm in thickness and 10.5 mm in outside diameter. The peak power density of the cell at temperatures between 650 and 850°C was in the range from 85 to 522 mW cm−2 and was greatly enhanced to the range from 308 to 1220 mW cm−2 by impregnating PdO into LSM-YSZ cathode. During a cell testing at 0.7 A cm−2 and 750°C for 282 h, the impregnated PdO particles grew by coalescence, which increased the cathode polarization resistance and so that decreased the cell performance. According to the degradation tendency, the cell performance will be stabilized in a longer run. PMID:25640168

Development and fabrication of large vented nickel--zinc cells. Final report. [300 Ah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donnel, C.P.I.

1975-12-01

A preliminary cell design for a 300-Ah vented nickel--zinc cell was established based on volume requirements and cell component materials selected by NASA Lewis Research Center. A 100-Ah cell configuration was derived from the 300-Ah cell design utilizing the same size electrodes, separators, and cell terminal hardware. The first cells fabricated were four groups of three cells each in the 100-Ah size. These 100-Ah experimental nickel--zinc cells had as common components the nickel positive electrodes (GFM), flexible inorganic separator (GFM) bags on the negative electrodes, pressed powder zinc oxide electrodes, and cell containers with hardware. The variations introduced were fourmore » differing electrolyte absorber (interseparator) systems used to encase the nickel positive electrodes of each cell group. The four groups of 100-Ah experimental vented nickel--zinc cells were tested to determine, based on cell performance, the best two interseparator systems. Using the two interseparator systems, two groups of experimental 300-AH cells were fabricated. Each group of three cells differed only in the interseparator material used. The six cells were filled, formed and tested to evaluate the interseparator materials and investigate the performance characteristics of the 300-Ah cell configuration and its components. (auth)« less

Primary lithium organic electrolyte battery BA-5588

NASA Astrophysics Data System (ADS)

Rosansky, M. G.

1982-07-01

This program concerns the development, fabrication and evaluation of a Lithium organic electrolyte battery designated BA-5588 ()/U which incorporates five series connected, hermetically sealed cells housed in a plastic case. Significant effort was directed towards cell optimization through controlled experimentation and evaluation of various design parameters. Demonstration of the effectiveness of the finalized design was accomplished by the performance of various electrical and abuse tests which included environmental exposure, prolonged thermal storage, electrical discharge under various thermal profiles, short circuit and discharge to zero volts as well as forced discharge. The resulting evaluation demonstrated the batteries ability to operate safely under all of the specified abusive environments and provide 100% of the specified service life requirements.

Development of first generation aerospace NiMH cells

NASA Technical Reports Server (NTRS)

Tinker, Lawrence; Dell, Dan; Wu, Tony; Rampel, Guy

1993-01-01

Gates Aerospace Batteries in conjunction with Gates Energy Products (GEP) has been developing NiMH technology for aerospace use since 1990. GEP undertook the development of NiMH technology for commercial cell applications in 1987. This program focused on wound cell technology for replacement of current NiCd technology. As an off shoot of this program small, wound cells were used to evaluate initial design options for aerospace prismatic cell designs. Early in 1991, the first aerospace prismatic cell designs were built in a 6 Ah cell configuration. These cells were used to initially characterize performance in prismatic configurations and begin early life cycle testing. Soon after the 6 Ah cells were on test, several 22 Ah cells were built to test other options. The results of testing of these cells were used to identify potential problem areas for long lived cells and develop solutions to those problems. Following these two cell builds, a set of 7 Ah cells was built to evaluate improvements to the technology. To date results from these tests are very promising. Cycle lives in excess of 2,200 LEO cycles at 50 percent DoD were achieved with cells continuing on test. Results from these cell tests are discussed and data presented to demonstrate feasibility of this technology for aerospace programs.

Potential of laryngeal muscle regeneration using induced pluripotent stem cell-derived skeletal muscle cells.

PubMed

Dirja, Bayu Tirta; Yoshie, Susumu; Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Nakamura, Ryosuke; Otsuki, Koshi; Nomoto, Yukio; Wada, Ikuo; Hazama, Akihiro; Omori, Koichi

2016-01-01

Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation.

A miniaturized bioreactor system for the evaluation of cell interaction with designed substrates in perfusion culture.

PubMed

Sun, T; Donoghue, P S; Higginson, J R; Gadegaard, N; Barnett, S C; Riehle, M O

2012-12-01

In tissue engineering, chemical and topographical cues are normally developed using static cell cultures but then applied directly to tissue cultures in three dimensions (3D) and under perfusion. As human cells are very sensitive to changes in the culture environment, it is essential to evaluate the performance of any such cues in a perfused environment before they are applied to tissue engineering. Thus, the aim of this research was to bridge the gap between static and perfusion cultures by addressing the effect of perfusion on cell cultures within 3D scaffolds. For this we developed a scaled-down bioreactor system, which allows evaluation of the effectiveness of various chemical and topographical cues incorporated into our previously developed tubular ε-polycaprolactone scaffold under perfused conditions. Investigation of two exemplary cell types (fibroblasts and cortical astrocytes) using the miniaturized bioreactor indicated that: (a) quick and firm cell adhesion in the 3D scaffold was critical for cell survival in perfusion culture compared with static culture; thus, cell-seeding procedures for static cultures might not be applicable, therefore it was necessary to re-evaluate cell attachment on different surfaces under perfused conditions before a 3D scaffold was applied for tissue cultures; (b) continuous medium perfusion adversely influenced cell spread and survival, which could be balanced by intermittent perfusion; (c) micro-grooves still maintained their influences on cell alignment under perfused conditions, while medium perfusion demonstrated additional influence on fibroblast alignment but not on astrocyte alignment on grooved substrates. This research demonstrated that the mini-bioreactor system is crucial for the development of functional scaffolds with suitable chemical and topographical cues by bridging the gap between static culture and perfusion culture. Copyright © 2011 John Wiley & Sons, Ltd.

Infiltrated La0.4Sr0.4Fe0.03Ni0.03Ti0.94O3 based anodes for all ceramic and metal supported solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Nielsen, Jimmi; Persson, Åsa H.; Sudireddy, Bhaskar R.; Irvine, John T. S.; Thydén, Karl

2017-12-01

For improved robustness, durability and to avoid severe processing challenges alternatives to the Ni:YSZ composite electrode is highly desirable. The Ni:YSZ composite electrode is conventionally used for solid oxide fuel cell and solid oxide electrolysis cell. In the present study we report on high performing nanostructured Ni:CGO electrocatalyst coated A site deficient Lanthanum doped Strontium Titanate (La0.4Sr0.4Fe0.03Ni0.03Ti0.94O3) based anodes. The anodes were incorporated into the co-sintered DTU metal supported solid oxide fuel cell design and large sized 12 cm × 12 cm cells were fabricated. The titanate material showed good processing characteristics and surface wetting properties towards the Ni:CGO electrocatalyst coating. The cell performances were evaluated on single cell level (active area 16 cm2) and a power density at 0.7 V and 700 °C of 0.650 Wcm-2 with a fuel utilization of 31% was achieved. Taking the temperature into account the performances of the studied anodes are among the best reported for redox stable and corrosion resistant alternatives to the conventional Ni:YSZ composite solid oxide cell electrode.

Cudraflavone C Induces Apoptosis of A375.S2 Melanoma Cells through Mitochondrial ROS Production and MAPK Activation.

PubMed

Lee, Chiang-Wen; Yen, Feng-Lin; Ko, Horng-Huey; Li, Shu-Yu; Chiang, Yao-Chang; Lee, Ming-Hsueh; Tsai, Ming-Horng; Hsu, Lee-Fen

2017-07-13

Melanoma is the most malignant form of skin cancer and is associated with a very poor prognosis. The aim of this study was to evaluate the apoptotic effects of cudraflavone C on A375.S2 melanoma cells and to determine the underlying mechanisms involved in apoptosis. Cell viability was determined using the MTT and real-time cytotoxicity assays. Flow cytometric evaluation of apoptosis was performed after staining the cells with Annexin V-FITC and propidium iodide. The mitochondrial membrane potential was evaluated using the JC-1 assay. Cellular ROS production was measured using the CellROX assay, while mitochondrial ROS production was evaluated using the MitoSOX assay. It was observed that cudraflavone C inhibited growth in A375.S2 melanoma cells, and promoted apoptosis via the mitochondrial pathway mediated by increased mitochondrial ROS production. In addition, cudraflavone C induced phosphorylation of MAPKs (p38, ERK, and JNK) and up-regulated the expression of apoptotic proteins (Puma, Bax, Bad, Bid, Apaf-1, cytochrome C, caspase-9, and caspase-3/7) in A375.S2 cells. Pretreatment of A375.S2 cells with MitoTEMPOL (a mitochondria-targeted antioxidant) attenuated the phosphorylation of MAPKs, expression of apoptotic proteins, and the overall progression of apoptosis. In summary, cudraflavone C induced apoptosis in A375.S2 melanoma cells by increasing mitochondrial ROS production; thus, activating p38, ERK, and JNK; and increasing the expression of apoptotic proteins. Therefore, cudraflavone C may be regarded as a potential form of treatment for malignant melanoma.

Thrust stand evaluation of engine performance improvement algorithms in an F-15 airplane

NASA Technical Reports Server (NTRS)

Conners, Timothy R.

1992-01-01

Results are presented from the evaluation of the performance seeking control (PSC) optimization algorithm developed by Smith et al. (1990) for F-15 aircraft, which optimizes the quasi-steady-state performance of an F100 derivative turbofan engine for several modes of operation. The PSC algorithm uses onboard software engine model that calculates thrust, stall margin, and other unmeasured variables for use in the optimization. Comparisons are presented between the load cell measurements, PSC onboard model thrust calculations, and posttest state variable model computations. Actual performance improvements using the PSC algorithm are presented for its various modes. The results of using PSC algorithm are compared with similar test case results using the HIDEC algorithm.

Development of small scale cell culture models for screening poloxamer 188 lot-to-lot variation.

PubMed

Peng, Haofan; Hall, Kaitlyn M; Clayton, Blake; Wiltberger, Kelly; Hu, Weiwei; Hughes, Erik; Kane, John; Ney, Rachel; Ryll, Thomas

2014-01-01

Shear protectants such as poloxamer 188 play a critical role in protecting cells during cell culture bioprocessing. Lot-to-lot variation of poloxamer 188 was experienced during a routine technology transfer across sites of similar scale and equipment. Cell culture medium containing a specific poloxamer 188 lot resulted in an unusual drop in cell growth, viability, and titer during manufacturing runs. After switching poloxamer lots, culture performance returned to the expected level. In order to control the quality of poloxamer 188 and thus maintain better consistency in manufacturing, multiple small scale screening models were developed. Initially, a 5L bioreactor model was established to evaluate cell damage by high sparge rates with different poloxamer 188 lots. Subsequently, a more robust, simple, and efficient baffled shake flask model was developed. The baffled shake flask model can be performed in a high throughput manner to investigate the cell damage in a bubbling environment. The main cause of the poor performance was the loss of protection, rather than toxicity. It was also suggested that suspicious lots can be identified using different cell line and media. The screening methods provide easy, yet remarkable models for understanding and controlling cell damage due to raw material lot variation as well as studying the interaction between poloxamer 188 and cells. © 2014 American Institute of Chemical Engineers.

Histopathologic and immunohistochemical sequelae of bariatric embolization in a porcine model.

PubMed

Paxton, Ben E; Alley, Christopher L; Crow, Jennifer H; Burchette, James; Weiss, Clifford R; Kraitchman, Dara L; Arepally, Aravind; Kim, Charles Y

2014-03-01

To evaluate the histopathologic sequelae of bariatric embolization on the gastric mucosa and to correlate with immunohistochemical evaluation of the gastric fundus, antrum, and duodenum. This study was performed on 12 swine stomach and duodenum specimens after necropsy. Of the 12 swine, 6 had previously undergone bariatric embolization of the gastric fundus, and the 6 control swine had undergone a sham procedure with saline. Gross pathologic, histopathologic, and immunohistochemical examinations of the stomach and duodenum were performed. Specifically, mucosal integrity, fibrosis, ghrelin-expressing cells, and gastrin-expressing cells were assessed. Gross and histopathologic evaluation of treatment animals showed healing or healed mucosal ulcers in 50% of animals, with gastritis in 100% of treatment animals and in five of six control animals. The ghrelin-immunoreactive mean cell density was significantly lower in the gastric fundus in the treated animals compared with control animals (15.3 vs 22.0, P < .01) but similar in the gastric antrum (9.3 vs 14.3, P = .08) and duodenum (8.5 vs 8.6, P = .89). The gastrin-expressing cell density was significantly lower in the antrum of treated animals compared with control animals (82.2 vs 126.4, P = .03). A trend toward increased fibrosis was suggested in the gastric fundus of treated animals compared with controls (P = .07). Bariatric embolization resulted in a significant reduction in ghrelin-expressing cells in the gastric fundus without evidence of upregulation of ghrelin-expressing cells in the duodenum. Healing ulcerations in half of treated animals underscores the need for additional refinement of this procedure. © 2014 Published by SIR on behalf of The Society of Interventional Radiology.

A novel shell-structure cell microcarrier (SSCM) for cell transplantation and bone regeneration medicine.

PubMed

Su, Kai; Gong, Yihong; Wang, Chunming; Wang, Dong-An

2011-06-01

The present study aims to develop a novel open and hollow shell-structure cell microcarrier (SSCM) to improve the anchorage-dependent cell (ADC) loading efficiency, increase the space for cell proliferation and tissue regeneration, and better propel its therapeutic effects. Gelatin particles were prepared with oil/water/oil (o/w/o) technique and modified by an adjustable surface crosslinking technique and subsequent release of uncrosslinked material. Optical microscopy and scanning electron microscopy (SEM) were utilized to observe the morphologies of the microcarriers. Cell loading tests were performed to evaluate the biocompatibilities and effect on osteogenesis of SSCM. SSCMs were successfully fabricated via the surface technique. The shell-structure could allow the cell to attach and grow on both outer and inner surface of sphere and provide adequate space for cell proliferation and extracellular matrix (ECM) secretion. The cell loading rate, proliferation rate and osteogenesis-related gene expressions on the SSCMs were higher than those on the spherical gelatin microcarriers. The outstanding performance of injectable SSCMs endowed with favorable micro-structure, desirable cytocompatibility and enhanced cell affinity makes them as a good choice as cell delivery vehicle for transplanting therapeutic cells towards the scope of tissue regeneration.

Effectiveness and biological compatibility of different generations of dentin adhesives.

PubMed

da Silva, João M F; Rodrigues, José R; Camargo, Carlos H R; Fernandes, Virgilio Vilas Boas; Hiller, Karl-Anton; Schweikl, Helmut; Schmalz, Gottfried

2014-01-01

Besides possessing good mechanical properties, dental materials should present a good biological behavior and should not injure the involved tissues. Bond strength and biocompatibility are both highly significant properties of dentin adhesives. For that matter, these properties of four generations of adhesive systems (Multi-Purpose/Single Bond/SE Plus/Easy Bond) were evaluated. Eighty bovine teeth had their dentin exposed (500- and 200-μm thickness). Adhesive was applied on the dentin layer of each specimen. Following that, the microshearing test was performed for all samples. A dentin barrier test was used for the cytotoxicity evaluation. Cell cultures (SV3NeoB) were collected from testing materials by means of 200- or 500-μm-thick dentin slices and placed in a cell culture perfusion chamber. Cell viability was measured 24 h post-exposition by means of a photometrical test (MTT test). The best bonding performance was shown by the single-step adhesive Easy Bond (21 MPa, 200 μm; 27 MPa, 500 μm) followed by Single Bond (15.6 MPa, 200 μm; 23.4 MPa, 500 μm), SE Plus (18.2 MPa, 200 μm; 20 MPa, 500 μm), and Multi-Purpose (15.2 MPa, 200 μm; 17.9 MPa, 500 μm). Regarding the cytotoxicity, Multi-Purpose slightly reduced the cell viability to 92% (200 μm)/93% (500 μm). Single Bond was reasonably cytotoxic, reducing cell viability to 71% (200 μm)/64% (500 μm). The self-etching adhesive Scotchbond SE decreased cell viability to 85% (200 μm)/71% (500 μm). Conversely, Easy Bond did not reduce cell viability in this test, regardless of the dentin thickness. Results showed that the one-step system had the best bond strength performance and was the least toxic to pulp cells. In multiple-step systems, a correct bonding technique must be done, and a pulp capping strategy is necessary for achieving good performance in both properties. The study showed a promising system (one-step self-etching), referring to it as a good alternative for specific cases, mainly due to its technical simplicity and good biological responses.

Performance Impact Associated with Ni-Based SOFCs Fueled with Higher Hydrocarbon-Doped Coal Syngas

NASA Astrophysics Data System (ADS)

Hackett, Gregory A.; Gerdes, Kirk; Chen, Yun; Song, Xueyan; Zondlo, John

2015-03-01

Energy generation strategies demonstrating high efficiency and fuel flexibility are desirable in the contemporary energy market. When integrated with a gasification process, a solid oxide fuel cell (SOFC) can produce electricity at efficiencies exceeding 50 pct by consuming fuels such as coal, biomass, municipal solid waste, or other opportunity wastes. The synthesis gas derived from such fuel may contain trace species (including arsenic, lead, cadmium, mercury, phosphorus, sulfur, and tars) and low concentration organic species that adversely affect the SOFC performance. This work demonstrates the impact of exposure of the hydrocarbons ethylene, benzene, and naphthalene at various concentrations. The cell performance degradation rate is determined for tests exceeding 500 hours at 1073 K (800 °C). Cell performance is evaluated during operation with electrochemical impedance spectroscopy, and exposed samples are post-operationally analyzed by scanning electron microscopy/energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The short-term performance is modeled to predict performances to the desired 40,000-hours operational lifetime for SOFCs. Possible hydrocarbon interactions with the nickel anode are postulated, and acceptable hydrocarbon exposure limits are discussed.

Evaluation program for secondary spacecraft cells: Cycle life test

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1979-01-01

The service life and storage stability for several storage batteries were determined. The batteries included silver-zinc batteries, nickel-cadmium batteries, and silver-cadmium batteries. The cell performance characteristics and limitations are to be used by spacecraft power systems planners and designers. A statistical analysis of the life cycle prediction and cause of failure versus test conditions is presented.

The Focinator v2-0 - Graphical Interface, Four Channels, Colocalization Analysis and Cell Phase Identification.

PubMed

Oeck, Sebastian; Malewicz, Nathalie M; Hurst, Sebastian; Al-Refae, Klaudia; Krysztofiak, Adam; Jendrossek, Verena

2017-07-01

The quantitative analysis of foci plays an important role in various cell biological methods. In the fields of radiation biology and experimental oncology, the effect of ionizing radiation, chemotherapy or molecularly targeted drugs on DNA damage induction and repair is frequently performed by the analysis of protein clusters or phosphorylated proteins recruited to so called repair foci at DNA damage sites, involving for example γ-H2A.X, 53BP1 or RAD51. We recently developed "The Focinator" as a reliable and fast tool for automated quantitative and qualitative analysis of nuclei and DNA damage foci. The refined software is now even more user-friendly due to a graphical interface and further features. Thus, we included an R-script-based mode for automated image opening, file naming, progress monitoring and an error report. Consequently, the evaluation no longer required the attendance of the operator after initial parameter definition. Moreover, the Focinator v2-0 is now able to perform multi-channel analysis of four channels and evaluation of protein-protein colocalization by comparison of up to three foci channels. This enables for example the quantification of foci in cells of a specific cell cycle phase.

Point of care assessment of melanoma tumor signaling and metastatic burden from μNMR analysis of tumor fine needle aspirates and peripheral blood.

PubMed

Gee, Michael S; Ghazani, Arezou A; Haq, Rizwan; Wargo, Jennifer A; Sebas, Matthew; Sullivan, Ryan J; Lee, Hakho; Weissleder, Ralph

2017-04-01

This study evaluates μNMR technology for molecular profiling of tumor fine needle aspirates and peripheral blood of melanoma patients. In vitro assessment of melanocyte (MART-1, HMB45) and MAP kinase signaling (pERK, pS6K) molecule expression was performed in human cell lines, while clinical validation was performed in an IRB-approved study of melanoma patients undergoing biopsy and blood sampling. Tumor FNA and blood specimens were compared with BRAF genetic analysis and cross-sectional imaging. μNMR in vitro analysis showed increased expression of melanocyte markers in melanoma cells as well as increased expression of phosphorylated MAP kinase targets in BRAF-mutant melanoma cells. Melanoma patient FNA samples showed increased pERK and pS6K levels in BRAF mutant compared with BRAF WT melanomas, with μNMR blood circulating tumor cell level increased with higher metastatic burden visible on imaging. These results indicate that μNMR technology provides minimally invasive point-of-care evaluation of tumor signaling and metastatic burden in melanoma patients. Copyright © 2016 Elsevier Inc. All rights reserved.

[Analysis of thyroid lesions in childhood recipients after hematopoietic stem cell transplantation].

PubMed

Maeda, Naoko; Hamajima, Takashi; Yambe, Yuko; Sekimizu, Masahiro; Horibe, Keizo

2013-03-01

We performed a physical examination and ultrasonography of the thyroid gland in 24 patients who had received hematopoietic stem cell transplantation with a total-body irradiation (TBI)-containing regimen during childhood. When ultrasonography revealed thyroid nodules larger than 1 cm in diameter, fine-needle aspiration biopsies were performed. Of 5 patients with palpable masses and thyroid nodules larger than 1 cm, adenomatous goiter was diagnosed in 4 cases and thyroid cancer in 1. Of the remaining 19 patients in whom no palpable mass was detected in the physical examination, 5 had thyroid nodules (including 1 adenomatous goiter), 6 had cystic lesions, and 8 exhibited no abnormalities on ultrasonography. No significant differences in sex, age at transplantation, interval between transplantation and evaluation, primary disease, preconditioning regimen, status at transplantation, stem cell source, chronic graft-versus-host disease, hypogonadism, or hypothyroidism were observed between patients with and without nodules. Individuals who received hematopoietic stem cell transplantation with a TBI-containing regimen are at risk of secondary thyroid cancer due to radiotherapy and require regular clinical evaluations of the thyroid gland by palpation, and ultrasonography should be incorporated into these checkups.

Oxymatrine Inhibits Proliferation and Migration While Inducing Apoptosis in Human Glioblastoma Cells

PubMed Central

Wang, Baocheng; Wang, Jiajia; Li, Qifeng; Meng, Wei

2016-01-01

Oxymatrine (OMT), an alkaloid derived from the traditional Chinese medicine herb Sophora flavescens Aiton, has been shown to exhibit anticancer properties on various types of cancer cells. In this study, we investigate the anticancer properties of OMT on human glioblastoma (GBM) cells and evaluate their underlying mechanisms. MTT assays were performed and demonstrated that OMT significantly inhibits the proliferation of GBM cells. Flow cytometry suggested that OMT at a concentration of 10−5 M may induce apoptosis in U251 and A172 cells. Western blot analyses demonstrated a significant increase in the expression of Bax and caspase-3 and a significant decrease in expression of Bcl-2 in both U251 and A172 cells. Additionally, OMT was found by transwell and high-content screening assays to decrease the migratory ability of the evaluated GBM cells. These findings suggest that the antitumor effects of OMT may be the result of inhibition of cell proliferation and migration and the induction of apoptosis by regulating the expression of apoptosis-associated proteins. OMT may represent a novel anticancer therapy for the treatment of GBM. PMID:27957488

Static Feed Water Electrolysis Subsystem Testing and Component Development

NASA Technical Reports Server (NTRS)

Koszenski, E. P.; Schubert, F. H.; Burke, K. A.

1983-01-01

A program was carried out to develop and test advanced electrochemical cells/modules and critical electromechanical components for a static feed (alkaline electrolyte) water electrolysis oxygen generation subsystem. The accomplishments were refurbishment of a previously developed subsystem and successful demonstration for a total of 2980 hours of normal operation; achievement of sustained one-person level oxygen generation performance with state-of-the-art cell voltages averaging 1.61 V at 191 ASF for an operating temperature of 128F (equivalent to 1.51V when normalized to 180F); endurance testing and demonstration of reliable performance of the three-fluid pressure controller for 8650 hours; design and development of a fluid control assembly for this subsystem and demonstration of its performance; development and demonstration at the single cell and module levels of a unitized core composite cell that provides expanded differential pressure tolerance capability; fabrication and evaluation of a feed water electrolyte elimination five-cell module; and successful demonstration of an electrolysis module pressurization technique that can be used in place of nitrogen gas during the standby mode of operation to maintain system pressure and differential pressures.

Experimental comparison of MCFC performance using three different biogas types and methane

NASA Astrophysics Data System (ADS)

Bove, Roberto; Lunghi, Piero

Biogas recovery is an environmentally friendly and cost-effective practice that is getting consensus in both the scientific and industrial community, as the growing number of projects demonstrate. The use of fuel cells as energy conversion systems increases the conversion efficiency, as well as the environmental benefits. Molten carbonate fuel cells (MCFC) operate at a temperature of about 650 °C, thus presenting a high fuel flexibility, compared to low temperature fuel cells. Aim of the present study is to compare the performance of an MCFC single cell, fuelled with different biogas types as well as methane. The biogases considered are derived from the following processes: (1) steam gasification in an entrained flow gasifier; (2) steam gasification in a duel interconnect fluidized bed gasifier; (3) biogas from an anaerobic digestion process. The performances are evaluated for different fuel utilization and current densities. The results are an essential starting point for a complete system design and demonstration.

Performance of strontium- and magnesium-doped lanthanum gallate electrolyte with lanthanum-doped ceria as a buffer layer for IT-SOFCs

NASA Astrophysics Data System (ADS)

Lee, Dokyol; Han, Ju-Hyeong; Kim, Eun-Gu; Song, Rak-Hyun; Shin, Dong-Ryul

La 0.8Sr 0.2Ga 0.8Mg 0.2O 2.8 (LSGM8080) powder, showing the highest electrical conductivity among LSGMs of various compositions, is synthesized using the glycine nitrate process (GNP) and used as the electrolyte for an intermediate-temperature solid oxide fuel cell (IT-SOFC). The LDC (Ce 0.55La 0.45O 1.775) powder is synthesized by a solid-state reaction and employed as the material for a buffer layer to prevent the reaction between the anode and electrolyte materials. The LDC also serves as the skeleton material for the anode. An anode-supported single cell with an active area of 1 cm 2 is constructed for performance evaluation. A single-cell test is performed at 750 and 800 °C. The maximum power density of the cell 459 and 664 mW cm -2 at 750 and 800 °C, respectively.

Thin film battery/fuel cell power generating system. Final report of the continuation contract (Tasks 1-4), April 1, 1978-March 31, 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-06-30

Research on the design, development, and testing of a high-temperature solid electrolyte (HTSOE) fuel cell is described in detail. Task 1 involves the development and refinement of fabrication processes for the porous support tube, fuel electrode, solid electrolyte, air electrode, and interconnection. Task 2 includes the life testing of cell components and the stack; task 3 involves the stack performance evaluation; task 4 includes demonstrating the reproducibility of 10 watt stacks. A cost, design and benefit study to evaluate the nature and worth of an industrial cogeneration application of the HTSOE fuel cell is underway. Here, promisng applications are nowmore » being considered, from which a single application has been selected as a basis for the study - an integrated aluminum production facility. (WHK)« less

Screening anti-tumor compounds from Ligusticum wallichii using cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry.

PubMed

Zhang, Tao; Ding, Yuanyuan; An, Hongli; Feng, Liuxin; Wang, Sicen

2015-07-14

Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry was developed. Tyrosine 367 Cysteine-HEK293 cells were used as cell membrane stationary phase. Specificity and reproducibility of the cell membrane chromatography was evaluated using 1-tert-butyl-3-{2-[4-(diethylamino)butylamino]-6-(3,5-dimethoxyphenyl)pyrido[2,3-d]pyrimidin-7-yl}urea, Nimodipine and dexamethasone acetate. Then, anti-tumor components acting on Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 were screened and identified from extracts of Ligusticum wallichii. Components from the extract were retained on the cell membrane chromatographic column. The retained fraction was directly eluted into high-performance liquid chromatography with mass spectrometry system for separation and identification. Finally, Levistolide A was identified as an active component from Ligusticum wallichii extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan colorimetric assay revealed that Levistolide A inhibits proliferation of overexpressing the mutated receptor cells with dose-dependent manner. Phosphorylation of fibroblast growth factor receptor 4 was also decrease under Levistolide A treatment. Flex dock simulation verified that Levistolide A could bind with the tyrosine kinase domain of fibroblast growth factor receptor 4. Therefore, Levistolide A screened by the cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry can arrest cell growth. In conclusion, the two-dimensional high-performance liquid chromatography method can screen and identify potential anti-tumor ingredients which specifically act on the tyrosine kinase domain of the mutated fibroblast growth factor receptor 4. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Satellite cell therapy – from mice to men

PubMed Central

2013-01-01

Satellite cells are rare mononuclear skeletal muscle-resident cells that are the chief contributors to regenerative myogenesis following muscle injury. Although first identified more than 50 years ago, it is only recently that the murine satellite cell has become molecularly defined with the ability to prospectively isolate these cells from their niche. Human satellite cells are considerably less well understood with relatively few studies having been performed on them. In this review, a critical evaluation of this literature is provided along with a discussion of the practical and methodological issues involved with research on human satellite cells. The therapeutic potential of these and other cells types is also discussed, and the various challenges that face satellite cell therapy are addressed. PMID:23369649

Novel Single-Cell Analysis Platform Based on a Solid-State Zinc-Coadsorbed Carbon Quantum Dots Electrochemiluminescence Probe for the Evaluation of CD44 Expression on Breast Cancer Cells.

PubMed

Qiu, Youyi; Zhou, Bin; Yang, Xiaojuan; Long, Dongping; Hao, Yan; Yang, Peihui

2017-05-24

A novel single-cell analysis platform was fabricated using solid-state zinc-coadsorbed carbon quantum dot (ZnCQDs) nanocomposites as an electrochemiluminescence (ECL) probe for the detection of breast cancer cells and evaluation of the CD44 expression level. Solid-state ZnCQDs nanocomposite probes were constructed through the attachment of ZnCQDs to gold nanoparticles and then the loading of magnetic beads to amplify the ECL signal, exhibiting a remarkable 120-fold enhancement of the ECL intensity. Hyaluronic acid (HA)-functionalized solid-state probes were used to label a single breast cancer cell by the specific recognition of HA with CD44 on the cell surface, revealing more stable, sensitive, and effective tagging in comparison with the water-soluble CQDs. This strategy exhibited a good analytical performance for the analysis of MDA-MB-231 and MCF-7 single cells with linear range from 1 to 18 and from 1 to 12 cells, respectively. Furthermore, this single-cell analysis platform was used for evaluation of the CD44 expression level of these two cell lines, in which the MDA-MB-231 cells revealed a 2.8-5.2-fold higher CD44 expression level. A total of 20 single cells were analyzed individually, and the distributions of the ECL intensity revealed larger variations, indicating the high cellular heterogeneity of the CD44 expression level on the same cell line. The as-proposed single-cell analysis platform might provide a novel protocol to effectively study the individual cellular function and cellular heterogeneity.

Synchronous occurrence of neuroendocrine colon carcinoma and hairy cell leukemia.

PubMed

Salemis, Nikolaos S; Pinialidis, Dionisios; Tsiambas, Evangelos; Gakis, Christos; Nakos, Georgios; Sambaziotis, Dimitrios; Christofyllakis, Charalambos

2011-09-01

BACKGROUND-PURPOSE: The risk of secondary malignancy development in patients with hairy cell leukemia has been evaluated in several studies with varying results. The aim of this study is to describe a case of synchronous occurrence of neuroendocrine colon carcinoma and hairy cell leukemia. A 69-year-old man presented with rectal bleeding. Colonoscopy revealed a rectal tumor, whereas biopsy specimens revealed a poorly differentiated carcinoma. During the preoperative evaluation, pancytopenia was detected. At laparotomy, a mass was detected 16 cm from the anal verge and an anterior resection of the rectum was performed. Detailed histological and immunohistochemical analyses revealed a poorly differentiated neuroendocrine carcinoma of the rectum. Postoperative evaluation of pancytopenia revealed hairy cell leukemia. The patient was initially treated with chemotherapy for hairy cell leukemia followed by chemotherapy for neuroendocrine colon carcinoma. Survival was 44 months. To our knowledge, synchronous occurrence of neuroendocrine colon carcinoma and hairy cell leukemia has not been previously reported in the literature. Given the rare incidence of both entities in the general population, it is highly unlikely that they occurred together by chance. Further research is needed to determine what would be the optimal management options of patients with simultaneous hairy cell leukemia and a neuroendocrine colon cancer.

Evaluation of a new automated microscopy urine sediment analyser - sediMAX conTRUST®.

PubMed

Bogaert, Laura; Peeters, Bart; Billen, Jaak

2017-04-01

This study evaluated the performance of the stand-alone sediMAX conTRUST (77Elektronika, Budapest, Hungary) analyser as an alternative to microscopic analysis of urine. The validation included a precision, carry-over, categorical correlation and diagnostic performance study with manual phase-contrast microscopy as reference method. A total of 260 routine urine samples were assessed. The within-run precision was much better at higher concentrations than at very low concentrations. The precision met our predefined limits for all the elements at the different concentrations, with the exception of the lowest RBC, the WBC, pathological casts and crystals count. There was no sample carry-over. The analyser showed good categorical agreement with manual microscopy for RBC and WBC counts, moderate agreement for yeast cells, crystals and squamous epithelial cells and bad agreement for non-squamous epithelial cells, bacteria and casts. Diagnostic performance was satisfying only for RBC, WBC and yeast cells. The number of false negative results was acceptable (≤4%) for all elements after connecting the sediMAX conTRUST with an automatic strip reader (AutionMAX) and after implementation of review rules. We conclude that the sediMAX conTRUST should be used as a screening tool in combination with an automatic strip reader, for the identification of normal samples. Therefore, adequate review rules should be defined. Manual microscopy is still required in 'flagged' pathological samples. Despite the poor analytical performance on pathological samples, the images on the screen can be used for interpretation without the microscope and can be stored as PDF-documents for archiving the results.

Combination screening in vitro identifies synergistically acting KP372-1 and cytarabine against acute myeloid leukemia.

PubMed

Österroos, A; Kashif, M; Haglund, C; Blom, K; Höglund, M; Andersson, C; Gustafsson, M G; Eriksson, A; Larsson, R

2016-10-15

Cytogenetic lesions often alter kinase signaling in acute myeloid leukemia (AML) and the addition of kinase inhibitors to the treatment arsenal is of interest. We have screened a kinase inhibitor library and performed combination testing to find promising drug-combinations for synergistic killing of AML cells. Cytotoxicity of 160 compounds in the library InhibitorSelect™ 384-Well Protein Kinase Inhibitor I was measured using the fluorometric microculture cytotoxicity assay (FMCA) in three AML cell lines. The 15 most potent substances were evaluated for dose-response. The 6 most cytotoxic compounds underwent combination synergy analysis based on the FMCA readouts after either simultaneous or sequential drug addition in AML cell lines. The 4 combinations showing the highest level of synergy were evaluated in 5 primary AML samples. Synergistic calculations were performed using the combination interaction analysis package COMBIA, written in R, using the Bliss independence model. Based on obtained results, an iterative combination search was performed using the therapeutic algorithmic combinatorial screen (TACS) algorithm. Of 160 substances, cell survival was ⩽50% at <0.5μM for Cdk/Crk inhibitor, KP372-1, synthetic fascaplysin, herbimycin A, PDGF receptor tyrosine kinase inhibitor IV and reference-drug cytarabine. KP372-1, synthetic fascaplysin or herbimycin A obtained synergy when combined with cytarabine in AML cell lines MV4-11 and HL-60. KP372-1 added 24h before cytarabine gave similar results in patient cells. The iterative search gave further improved synergy between cytarabine and KP372-1. In conclusion, our in vitro studies suggest that combining KP372-1 and cytarabine is a potent and synergistic drug combination in AML. Copyright © 2016 Elsevier Inc. All rights reserved.

Automatic Stem Cell Detection in Microscopic Whole Mouse Cryo-imaging

PubMed Central

Wuttisarnwattana, Patiwet; Gargesha, Madhusudhana; Hof, Wouter van’t; Cooke, Kenneth R.

2016-01-01

With its single cell sensitivity over volumes as large as or larger than a mouse, cryo-imaging enables imaging of stem cell biodistribution, homing, engraftment, and molecular mechanisms. We developed and evaluated a highly automated software tool to detect fluorescently labeled stem cells within very large (~200GB) cryo-imaging datasets. Cell detection steps are: preprocess, remove immaterial regions, spatially filter to create features, identify candidate pixels, classify pixels using bagging decision trees, segment cell patches, and perform 3D labeling. There are options for analysis and visualization. To train the classifier, we created synthetic images by placing realistic digital cell models onto cryo-images of control mice devoid of cells. Very good cell detection results were (precision=98.49%, recall=99.97%) for synthetic cryo-images, (precision=97.81%, recall=97.71%) for manually evaluated, actual cryo-images, and <1% false positives in control mice. An α-multiplier applied to features allows one to correct for experimental variations in cell brightness due to labeling. On dim cells (37% of standard brightness), with correction, we improved recall (49.26%→99.36%) without a significant drop in precision (99.99%→99.75%). With tail vein injection, multipotent adult progenitor cells in a graft-versus-host-disease model in the first days post injection were predominantly found in lung, liver, spleen, and bone marrow. Distribution was not simply related to blood flow. The lung contained clusters of cells while other tissues contained single cells. Our methods provided stem cell distribution anywhere in mouse with single cell sensitivity. Methods should provide a rational means of evaluating dosing, delivery methods, cell enhancements, and mechanisms for therapeutic cells. PMID:26552080

Effect of photoanode surface coverage by a sensitizer on the photovoltaic performance of titania based CdS quantum dot sensitized solar cells.

PubMed

Prasad, Rajendra M B; Pathan, Habib M

2016-04-08

In spite of the promising design and architecture, quantum dot sensitized solar cells (QDSSCs) have a long way to go before they attain the actual projected photoconversion efficiencies. Such an inferior performance displayed by QDSSCs is primarily because of many unwanted recombination losses of charge carriers at various interfaces of the cell. Electron recombination due to back electron transfer at the photoanode/electrolyte interface is an important one that needs to be addressed, to improve the efficiency of these third generation nanostructured solar cells. The present work highlights the importance of conformal coverage of CdS quantum dots (QDs) on the surface of the nanocrystalline titania photoanode in arresting such recombinations, leading to improvement in the performance of the cells. Using the successive ionic layer adsorption and reaction (SILAR) process, photoanodes are subjected to different amounts of CdS QD sensitization by varying the number of cycles of deposition. The sensitized electrodes are characterized using UV-visible spectroscopy, cyclic voltammetry and transmission electron microscopy to evaluate the extent of surface coverage of titania electrodes by QDs. Sandwich solar cells are then fabricated using these electrodes and characterized employing electrochemical impedance spectroscopy and J-V characteristics. It is observed that maximum solar cell efficiency is obtained for photoanodes with conformal coating of QDs and any further deposition of sensitizer leads to QD aggregation and so reduces the performance of the solar cells.

Biological X-ray irradiator characterization for use with small animals and cells.

PubMed

Bruno, A Colello; Mazaro, S J; Amaral, L L; Rego, E M; Oliveira, H F; Pavoni, J F

2017-03-02

This study presents the characterization of an X-ray irradiator through dosimetric tests, which confirms the actual dose rate that small animals and cells will be exposed to during radiobiological experiments. We evaluated the linearity, consistency, repeatability, and dose distribution in the positions in which the animals or cells are placed during irradiation. In addition, we evaluated the performance of the X-ray tube (voltage and tube operating current), the radiometric survey (leakage radiation) and safety devices. The irradiator default setting was established as 160 kV and 25 mA. Tests showed that the dose rate was linear overtime (R2=1) and remained stable for long (constant) and short (repeatability) intervals between readings. The mean dose rate inside the animal cages was 1.27±0.06 Gy/min with a uniform beam of 95.40% (above the minimum threshold guaranteed by the manufacturer). The mean dose rate inside the cell plates was 0.92±0.19 Gy/min. The dose rate dependence with tube voltage and current presented a quadratic and linear relationship, respectively. There was no observed mechanical failure during evaluation of the irradiator safety devices and the radiometric survey obtained a maximum ambient equivalent dose rate of 0.26 mSv/h, which exempts it from the radiological protection requirements of the International Atomic Energy Agency. The irradiator characterization enables us to perform radiobiological experiments, and assists or even replaces traditional therapy equipment (e.g., linear accelerators) for cells and small animal irradiation, especially in early research stages.

Antibody-protein interactions: benchmark datasets and prediction tools evaluation

PubMed Central

Ponomarenko, Julia V; Bourne, Philip E

2007-01-01

Background The ability to predict antibody binding sites (aka antigenic determinants or B-cell epitopes) for a given protein is a precursor to new vaccine design and diagnostics. Among the various methods of B-cell epitope identification X-ray crystallography is one of the most reliable methods. Using these experimental data computational methods exist for B-cell epitope prediction. As the number of structures of antibody-protein complexes grows, further interest in prediction methods using 3D structure is anticipated. This work aims to establish a benchmark for 3D structure-based epitope prediction methods. Results Two B-cell epitope benchmark datasets inferred from the 3D structures of antibody-protein complexes were defined. The first is a dataset of 62 representative 3D structures of protein antigens with inferred structural epitopes. The second is a dataset of 82 structures of antibody-protein complexes containing different structural epitopes. Using these datasets, eight web-servers developed for antibody and protein binding sites prediction have been evaluated. In no method did performance exceed a 40% precision and 46% recall. The values of the area under the receiver operating characteristic curve for the evaluated methods were about 0.6 for ConSurf, DiscoTope, and PPI-PRED methods and above 0.65 but not exceeding 0.70 for protein-protein docking methods when the best of the top ten models for the bound docking were considered; the remaining methods performed close to random. The benchmark datasets are included as a supplement to this paper. Conclusion It may be possible to improve epitope prediction methods through training on datasets which include only immune epitopes and through utilizing more features characterizing epitopes, for example, the evolutionary conservation score. Notwithstanding, overall poor performance may reflect the generality of antigenicity and hence the inability to decipher B-cell epitopes as an intrinsic feature of the protein. It is an open question as to whether ultimately discriminatory features can be found. PMID:17910770

The hollow fiber bioreactor as a stroma-supported, serum-free ex vivo expansion platform for human umbilical cord blood cells.

PubMed

Xue, Cao; Kwek, Kenneth Y C; Chan, Jerry K Y; Chen, Qingfeng; Lim, Mayasari

2014-07-01

The bone marrow microenvironment plays an integral role in the regulation of hematopoiesis. Residing stromal cells and the extracellular matrix in the bone marrow microenvironment provide biological signals that control hematopoietic stem cell (HSC) function. In this study, we developed a bio-mimetic co-culture platform using the hollow fiber bioreactor (HFBR) for ex vivo expansion of HSCs. We evaluated the efficacy of such a platform in comparison to standard cultures performed on tissue culture polystyrene (TCP), using a human stromal cell line (HS-5) as stromal support, co-cultured with lineage-depleted human cord blood cells in serum-free medium supplemented with a cytokine cocktail. Our results showed that the performance of the HFBR in supporting total cell and CD34(+) progenitor cell expansion was comparable to that of cultures on TCP. Cells harvested from the HFBR had a higher clonogenic ability. The performance of ex vivo-expanded cells from the HFBR in hematopoietic reconstitution in humanized mice was comparable to that of the TCP control. Scanning electron microscopy revealed that stroma cell growth inside the HFBR created a three-dimensional cell matrix architecture. These findings demonstrate the feasibility of utilizing the HFBR for creating a complex cell matrix architecture, which may provide good in vitro mimicry of the bone marrow, supporting large-scale expansion of HSCs. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessment of orthodontic biomaterials' cytotoxicity: an in vitro study on cell culture.

PubMed

Sodor, Alina; Ogodescu, Alexandru Simion; Petreuş, Tudor; Şişu, Alina Maria; Zetu, Irina Nicoleta

2015-01-01

Orthodontists use various biomaterials such as molar bands, brackets, archwires, transpalatal archwires, facial masks and other auxiliary devices. One of the essential properties of these materials should be the biocompatibility. The aim of this study was to evaluate the biocompatibility of some orthodontic biomaterials like stainless steel archwires, brackets and NiTi (nickel-titanium alloy) coil springs. The studies were performed in vitro using human fibroblasts cultures on which the orthodontic materials were applied. The positive control was the copper amalgam. Readings of the cell reactions were performed at three and six days. It was observed that the materials used in the study cause cell alterations of variable intensity. The metallic brackets represent an important cell stress factor causing shape changes. For the metallic brackets, a preferential tropism for different areas of the bracket was also obvious. We observed a preferential tropism for the areas between the NiTi coil spring spirals. For the stainless steel archwires, we observed at six days a decay of cell density and also a higher amount of cells near the archwire areas on which bends were performed. All biomaterials analyzed in our study cause cellular changes of varying intensity without necessarily showing a cytotoxic character.

Solid oxide fuel cell anode degradation by the effect of hydrogen chloride in stack and single cell environments

NASA Astrophysics Data System (ADS)

Madi, Hossein; Lanzini, Andrea; Papurello, Davide; Diethelm, Stefan; Ludwig, Christian; Santarelli, Massimo; Van herle, Jan

2016-09-01

The poisoning effect by hydrogen chloride (HCl) on state-of-the-art Ni anode-supported solid oxide fuel cells (SOFCs) at 750 °C is evaluated in either hydrogen or syngas fuel. Experiments are performed on single cells and short stacks and HCl concentration in the fuel gas is increased from 1 ppm(v) up to 1000 ppm(v) at different current densities. Characterization methods such as cell voltage monitoring vs. time and electrochemical impedance response analysis (distribution of relaxation times (DRT), equivalent electrical circuit) are used to identify the prevailing degradation mechanism. Single cell experiments revealed that the poisoning is more severe when feeding with hydrogen than with syngas. Performance loss is attributed to the effects of HCl adsorption onto nickel surfaces, which lowered the catalyst activity. Interestingly, in syngas HCl does not affect stack performance even at concentrations up to 500 ppm(v), even when causing severe corrosion of the anode exhaust pipe. Furthermore, post-test analysis suggests that chlorine is present on the nickel particles in the form of adsorbed chlorine, rather than forming a secondary phase of nickel chlorine.

Experimental study of a fuel cell power train for road transport application

NASA Astrophysics Data System (ADS)

Corbo, P.; Corcione, F. E.; Migliardini, F.; Veneri, O.

The development of fuel cell electric vehicles requires the on-board integration of fuel cell systems and electric energy storage devices, with an appropriate energy management system. The optimization of performance and efficiency needs an experimental analysis of the power train, which has to be effected in both stationary and transient conditions (including standard driving cycles). In this paper experimental results concerning the performance of a fuel cell power train are reported and discussed. In particular characterization results for a small sized fuel cell system (FCS), based on a 2.5 kW PEM stack, alone and coupled to an electric propulsion chain of 3.7 kW are presented and discussed. The control unit of the FCS allowed the main stack operative parameters (stoichiometric ratio, hydrogen and air pressure, temperature) to be varied and regulated in order to obtain optimized polarization and efficiency curves. Experimental runs effected on the power train during standard driving cycles have allowed the performance and efficiency of the individual components (fuel cell stack and auxiliaries, dc-dc converter, traction batteries, electric engine) to be evaluated, evidencing the role of output current and voltage of the dc-dc converter in directing the energy flows within the propulsion system.

Lymphatic Muscle Cells in Rat Mesenteric Lymphatic Vessels of Various Ages

PubMed Central

Bridenbaugh, Eric A.; Nizamutdinova, Irina Tsoy; Jupiter, Daniel; Nagai, Takashi; Thangaswamy, Sangeetha; Chatterjee, Victor

2013-01-01

Abstract Background Recent studies on aging-associated changes in mesenteric lymph flow in situ demonstrated predominance of the severe negative chronotropic effect of aging on the contractility of aged mesenteric lymphatic vessels (MLV). At the same time, contraction amplitude of the aged vessels was only slightly diminished by aging and can be rapidly stimulated within 5–15 minutes. However, the detailed quantitative evaluation of potential aging-associated changes in muscle cells investiture in MLV has never been performed. Methods and Results In this study we, for the first time, performed detailed evaluation of muscle cells investiture in MLV in reference to the position of lymphatic valve in different zones of lymphangion within various age groups (3-mo, 9-mo and 24-mo Fischer-344 rats). Using visual and quantitative analyses of the images of MLV immunohistochemically labeled for actin, we confirmed that the zones located close upstream (pre-valve zones) and above lymphatic valves (valve zones) possess the lowest investiture of lymphatic muscle cells. Most of the high muscle cells investiture zones exist downstream to the lymphatic valve (post-valve zones). The muscle cells investiture of these zones is not affected by aging, while pre-valve and valve zones demonstrate significant aging-associated decrease in muscle cells investiture. Conclusions The low muscle cells investiture zones in lymphatic vessels consist of predominantly longitudinally oriented muscle cells which are positioned in pre-valve and valve zones and connect adjacent lymphangions. These cells may provide important functional impact on the biomechanics of the lymphatic valve gating and electrical coupling between lymphangions, while their aging-associated changes may delimit adaptive reserves of aged lymphatic vessels. PMID:23531183

Development of advanced fuel cell system

NASA Technical Reports Server (NTRS)

Gitlow, B.; Meyer, A. P.; Bell, W. F.; Martin, R. E.

1978-01-01

An experimental program was conducted continuing the development effort to improve the weight, life, and performance characteristics of hydrogen-oxygen alkaline fuel cells for advanced power systems. These advanced technology cells operate with passive water removal which contributes to a lower system weight and extended operating life. Endurance evaluation of two single cells and two, two-cell plaques was continued. Three new test articles were fabricated and tested. A single cell completed 7038 hours of endurance testing. This cell incorporated a Fybex matrix, hybrid-frame, PPF anode, and a 90 Au/10 Pt cathode. This configuration was developed to extend cell life. Two cell plaques with dedicated flow fields and manifolds for all fluids did not exhibit the cell-to-cell electrolyte transfer that limited the operating life of earlier multicell plaques.

Qualification testing of general electric 50 Ah nickel-cadmium cells with new separator and new positive plate processing

NASA Astrophysics Data System (ADS)

Morrow, G. W.

1986-09-01

Forty-two 50 Ah aerospace nickel-cadmium cells were delivered to Goddard Space Flight Center (GSFC) by General Electric (GE) in February, 1985, for the purpose of evaluating and qualifying a new nylon separator material Pellon 2536, and the new GE Positive Plate Nickel Attack Control Passivation process. Testing began in May, 1985, at the Naval Weapons Support Center (NWSC) in Crane, Indiana with standard initial evaluation tests. Life cycling in both Low Earth Orbit (LEO) and Geosynchronous Orbit (GEO) began in July, 1985, with approximately 1200 LEO cycles complete at this writting. Early test results show that cells with positive plate passivation exhibit higher than normal charge voltage characteristics. Other aspects of performance were nominal.

Qualification Testing of General Electric 50 Ah Nickel-Cadmium Cells with New Separator and New Positive Plate Processing

NASA Technical Reports Server (NTRS)

Morrow, G. W.

1986-01-01

Forty-two 50 Ah aerospace nickel-cadmium cells were delivered to Goddard Space Flight Center (GSFC) by General Electric (GE) in February, 1985, for the purpose of evaluating and qualifying a new nylon separator material Pellon 2536, and the new GE Positive Plate Nickel Attack Control Passivation process. Testing began in May, 1985, at the Naval Weapons Support Center (NWSC) in Crane, Indiana with standard initial evaluation tests. Life cycling in both Low Earth Orbit (LEO) and Geosynchronous Orbit (GEO) began in July, 1985, with approximately 1200 LEO cycles complete at this writting. Early test results show that cells with positive plate passivation exhibit higher than normal charge voltage characteristics. Other aspects of performance were nominal.

Hubble Space telescope thermal cycle test report for large solar array samples with BSFR cells (Sample numbers 703 and 704)

NASA Technical Reports Server (NTRS)

Alexander, D. W.

1992-01-01

The Hubble space telescope (HST) solar array was designed to meet specific output power requirements after 2 years in low-Earth orbit, and to remain operational for 5 years. The array, therefore, had to withstand 30,000 thermal cycles between approximately +100 and -100 C. The ability of the array to meet this requirement was evaluated by thermal cycle testing, in vacuum, two 128-cell solar cell modules that exactly duplicated the flight HST solar array design. Also, the ability of the flight array to survive an emergency deployment during the dark (cold) portion of an orbit was evaluated by performing a cold-roll test using one module.

Efficiency of a cleaning protocol for the removal of enterotoxigenic Staphylococcus aureus strains in dairy plants.

PubMed

Martin, José Guilherme Prado; de Oliveira E Silva, Gabriela; da Fonseca, Carolina Rodrigues; Morales, Caio Baptista; Souza Pamplona Silva, Caroline; Miquelluti, Daniel Lima; Porto, Ernani

2016-12-05

Staphylococci are considered a major concern in dairy plants mainly due to the intensive production flow, automation of processing plants and increased demand in the microbiological quality of dairy products. This study aimed to identify S. aureus strains isolated from three Brazilian dairy plants, evaluate the influence of time, temperature and contact surface on the bacterial adhesion process, as well as the efficiency of simulated hygiene and sanitation protocol in removing adhered cells. For genotypic analyses, the presence of icaA and icaD in strains was evaluated. Adherence assays were performed in biofilm reactor, comparing the influence of 2 temperatures (5°C and 35°C), 2 surfaces (stainless steel and polypropylene) and 4 contact times (3, 6, 12h and post-sanitization). To evaluate the process effectiveness in removing adhered cells, neutral detergent and sanitizing agent based on sodium hypochlorite were used in order to simulate the situation observed in one of the dairy plants analyzed. The presence of icaA and icaD genes was determined in 75.3% and 77.6% of strains, respectively; 70.6% of isolates showed both genes, whereas 17.6% showed no genes. Genes for enterotoxin production were found in all samples, relating to SEG and SEH toxins. The number of cells adhered on both surfaces was about 3 and 6 log 10 CFU/cm 2 at temperatures of 5°C and 35°C, respectively, for most situations evaluated, with significant increase over the evaluation period. In general, the temperature of 35°C favored greater adherence of S. aureus. At 5°C, there was a considerable number of adhered cells, but in populations significantly lower than those observed at 35°C. The cleaning and sanitizing protocol was ineffective in removing adhered cells; better performance of sodium hypochlorite was observed at 5°C, which should be related to lower adherence observed at this temperature. Thus, the process was not able to reduce the number of S. aureus bacteria adhered on both surfaces to safe levels under the conditions evaluated. Copyright © 2016 Elsevier B.V. All rights reserved.

Treating cell culture media with UV irradiation against adventitious agents: minimal impact on CHO performance.

PubMed

Yen, Sandi; Sokolenko, Stanislav; Manocha, Bhavik; Blondeel, Eric J M; Aucoin, Marc G; Patras, Ankit; Daynouri-Pancino, Farnaz; Sasges, Michael

2014-01-01

Sterility of cell culture media is an important concern in biotherapeutic processing. In large scale biotherapeutic production, a unit contamination of cell culture media can have costly effects. Ultraviolet (UV) irradiation is a sterilization method effective against bacteria and viruses while being non-thermal and non-adulterating in its mechanism of action. This makes UV irradiation attractive for use in sterilization of cell culture media. The objective of this study was to evaluate the effect of UV irradiation of cell culture media in terms of chemical composition and the ability to grow cell cultures in the treated media. The results showed that UV irradiation of commercial cell culture media at relevant disinfection doses impacted the chemical composition of the media with respect to several carboxylic acids, and to a minimal extent, amino acids. The cumulative effect of these changes, however, did not negatively influence the ability to culture Chinese Hamster Ovary cells, as evaluated by cell viability, growth rate, and protein titer measurements in simple batch growth compared with the same cells cultured in control media exposed to visible light. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

Evaluation of cytotoxicity of new trans-palladium(II) complex in human cells in vitro.

PubMed

Kontek, Renata; Matławska-Wasowska, Ksenia; Kalinowska-Lis, Urszula; Kontek, Bogdan; Ochocki, Justyn

2011-01-01

Studies of cytotoxicity allow to elucidate the mechanisms by which chemical compounds influence cells and tissues. On the basis of the structural analogy between platinum(II) and palladium(II) complexes, a variety of studies on palladium(II) compounds as potential anticancer drugs have been carried out (1, 2). The cytotoxicity was evaluated by MTT assay. Abilities of trans-palladium(II) complex containing diethyl (pyridin-2-ylmethyl)phosphates as non-leaving ligands (trans-[PdCl2(2-pmOpe 2)]) to induce apoptosis and necrosis in normal lymphocytes, A549 cells and HT29 cell lines were performed by use of fluorochrome staining. The obtained results revealed, that the new trans-palladium(II) complex was more cytotoxic against A549 and HT29 tumor cells than on the normal lymphocytes in vitro. The novel complex induces apoptosis in all tested cells, but in lymphocytes to a lesser degree. The compound tested also induced significant amounts of necrotic cells, which exceeded the level of apoptotic cell fractions. The results demonstrate that the trans-Pd(II) complex showed substantial cytotoxic activity against A549 and HT29 tumor cells and indicate that the new trans-palladium(II) complex effectively inhibited cancer cells growth.

In vivo imaging of transplanted hematopoietic stem and progenitor cells in mouse calvarium bone marrow

PubMed Central

Lo Celso, Cristina; Lin, Charles P; Scadden, David T

2011-01-01

In vivo imaging of transplanted hematopoietic stem and progenitor cells (HSPCs) was developed to investigate the relationship between HSPCs and components of their microenvironment in the bone marrow. In particular, it allows a direct observation of the behavior of hematopoietic cells during the first few days after transplantation, when the critical events in homing and early engraftment are occurring. By directly imaging these events in living animals, this method permits a detailed assessment of functions previously evaluated by crude assessments of cell counts (homing) or after prolonged periods (engraftment). This protocol offers a new means of investigating the role of cell-intrinsic and cell-extrinsic molecular regulators of hematopoiesis during the early stages of transplantation, and it is the first to allow the study of cell-cell interactions within the bone marrow in three dimensions and in real time. In this paper, we describe how to isolate, label and inject HSPCs, as well as how to perform calvarium intravital microscopy and analyze the resulting images. A typical experiment can be performed and analyzed in ~1 week. PMID:21212779

Bone Marrow Stem Cells and Ear Framework Reconstruction.

PubMed

Karimi, Hamid; Emami, Seyed-Abolhassan; Olad-Gubad, Mohammad-Kazem

2016-11-01

Repair of total human ear loss or congenital lack of ears is one of the challenging issues in plastic and reconstructive surgery. The aim of the present study was 3D reconstruction of the human ear with cadaveric ear cartilages seeded with human mesenchymal stem cells. We used cadaveric ear cartilages with preserved perichondrium. The samples were divided into 2 groups: group A (cartilage alone) and group B (cartilage seeded with a mixture of fibrin powder and mesenchymal stem cell [1,000,000 cells/cm] used and implanted in back of 10 athymic rats). After 12 weeks, the cartilages were removed and shape, size, weight, flexibility, and chondrocyte viability were evaluated. P value <0.05 was considered significant. In group A, size and weight of cartilages clearly reduced (P < 0.05) and then shape and flexibility (torsion of cartilages in clockwise and counterclockwise directions) were evaluated, which were found to be significantly reduced (P > 0.05). After staining with hematoxylin and eosin and performing microscopic examination, very few live chondrocytes were found in group A. In group B, size and weight of samples were not changed (P < 0.05); the shape and flexibility of samples were well maintained (P < 0.05) and on performing microscopic examination of cartilage samples, many live chondrocytes were found in cartilage (15-20 chondrocytes in each microscopic field). In samples with human stem cell, all variables (size, shape, weight, and flexibility) were significantly maintained and abundant live chondrocytes were found on performing microscopic examination. This method may be used for reconstruction of full defect of auricles in humans.

Asialoglycoprotein receptor 1 is a specific cell-surface marker for isolating hepatocytes derived from human pluripotent stem cells

PubMed Central

Peters, Derek T.; Henderson, Christopher A.; Warren, Curtis R.; Friesen, Max; Xia, Fang; Becker, Caroline E.; Musunuru, Kiran; Cowan, Chad A.

2016-01-01

ABSTRACT Hepatocyte-like cells (HLCs) are derived from human pluripotent stem cells (hPSCs) in vitro, but differentiation protocols commonly give rise to a heterogeneous mixture of cells. This variability confounds the evaluation of in vitro functional assays performed using HLCs. Increased differentiation efficiency and more accurate approximation of the in vivo hepatocyte gene expression profile would improve the utility of hPSCs. Towards this goal, we demonstrate the purification of a subpopulation of functional HLCs using the hepatocyte surface marker asialoglycoprotein receptor 1 (ASGR1). We analyzed the expression profile of ASGR1-positive cells by microarray, and tested their ability to perform mature hepatocyte functions (albumin and urea secretion, cytochrome activity). By these measures, ASGR1-positive HLCs are enriched for the gene expression profile and functional characteristics of primary hepatocytes compared with unsorted HLCs. We have demonstrated that ASGR1-positive sorting isolates a functional subpopulation of HLCs from among the heterogeneous cellular population produced by directed differentiation. PMID:27143754

Possible involvement of miRNAs in tropism of Parvovirus B19.

PubMed

Anbarlou, Azadeh; AkhavanRahnama, Mahshid; Atashi, Amir; Soleimani, Masoud; Arefian, Ehsan; Gallinella, Giorgio

2016-03-01

Human Parvovirus B19 (PVB19) is one of the most important pathogens that targets erythroid lineage. Many factors were mentioned for restriction to erythroid progenitor cells (EPCs). Previous studies showed that in non-permissive cells VP1 and VP2 (structural proteins) mRNAs were detected but could not translate to proteins. A bioinformatics study showed that this inhibition might be due to specific microRNAs (miRNAs) present in non-permissive cells but not in permissive EPCs. To confirm the hypothesis, we evaluated the effect of miRNAs on VP expression. CD34(+) HSCs were separated from cord blood. Then, CD34(+) cells were treated with differentiation medium to obtain CD36(+) EPCs. To evaluate the effect of miRNAs on VP expression in MCF7 and HEK-293 cell lines (non-permissive cells) and CD36(+) EPCs, dual luciferase assay was performed in presence of shRNAs against Dicer and Drosha to disrupt miRNA biogenesis. QRT-PCR was performed to check down-regulation of Dicer and Drosha after transfection. All measurements were done in triplicate. Data means were compared using one-way ANOVAs. MicroRNA prediction was done by the online microRNA prediction tools. No significant difference was shown in luciferase activity of CD36(+) EPCs after co-transfection with shRNAs, while it was significant in non-permissive cells. Our study revealed that miRNAs may be involved in inhibition of VP expression in non-permissive cells, although further studies are required to demonstrate which miRNAs exactly are involved in regulation of PVB19 replication.

Fabrication Method for Laboratory-Scale High-Performance Membrane Electrode Assemblies for Fuel Cells.

PubMed

Sassin, Megan B; Garsany, Yannick; Gould, Benjamin D; Swider-Lyons, Karen E

2017-01-03

Custom catalyst-coated membranes (CCMs) and membrane electrode assemblies (MEAs) are necessary for the evaluation of advanced electrocatalysts, gas diffusion media (GDM), ionomers, polymer electrolyte membranes (PEMs), and electrode structures designed for use in next-generation fuel cells, electrolyzers, or flow batteries. This Feature provides a reliable and reproducible fabrication protocol for laboratory scale (10 cm 2 ) fuel cells based on ultrasonic spray deposition of a standard Pt/carbon electrocatalyst directly onto a perfluorosulfonic acid PEM.

Magnetic manipulation device for the optimization of cell processing conditions.

PubMed

Ito, Hiroshi; Kato, Ryuji; Ino, Kosuke; Honda, Hiroyuki

2010-02-01

Variability in human cell phenotypes make it's advancements in optimized cell processing necessary for personalized cell therapy. Here we propose a strategy of palm-top sized device to assist physically manipulating cells for optimizing cell preparations. For the design of such a device, we combined two conventional approaches: multi-well plate formatting and magnetic cell handling using magnetite cationic liposomes (MCLs). From our previous works, we showed the labeling applications of MCL on adhesive cells for various tissue engineering approaches. To feasibly transfer cells in multi-well plate, we here evaluated the magnetic response of MCL-labeled suspension type cells. The cell handling performance of Jurkat cells proved to be faster and more robust compared to MACS (Magnetic Cell Sorting) bead methods. To further confirm our strategy, prototype palm-top sized device "magnetic manipulation device (MMD)" was designed. In the device, the actual cell transportation efficacy of Jurkat cells was satisfying. Moreover, as a model of the most distributed clinical cell processing, primary peripheral blood mononuclear cells (PBMCs) from different volunteers were evaluated. By MMD, individual PBMCs indicated to have optimum Interleukin-2 (IL-2) concentrations for the expansion. Such huge differences of individual cells indicated that MMD, our proposing efficient and self-contained support tool, could assist the feasible and cost-effective optimization of cell processing in clinical facilities. Copyright (c) 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Overexpression of syndecan-1, MUC-1, and putative stem cell markers in breast cancer leptomeningeal metastasis: a cerebrospinal fluid flow cytometry study.

PubMed

Cordone, Iole; Masi, Serena; Summa, Valentina; Carosi, Mariantonia; Vidiri, Antonello; Fabi, Alessandra; Pasquale, Alessia; Conti, Laura; Rosito, Immacolata; Carapella, Carmine Maria; Villani, Veronica; Pace, Andrea

2017-04-11

Cancer is a mosaic of tumor cell subpopulations, where only a minority is responsible for disease recurrence and cancer invasiveness. We focused on one of the most aggressive circulating tumor cells (CTCs) which, from the primitive tumor, spreads to the central nervous system (CNS), evaluating the expression of prognostic and putative cancer stem cell markers in breast cancer (BC) leptomeningeal metastasis (LM). Flow cytometry immunophenotypic analysis of cerebrospinal fluid (CSF) samples (4.5 ml) was performed in 13 consecutive cases of BCLM. Syndecan-1 (CD138), MUC-1 (CD227) CD45, CD34, and the putative cancer stem cell markers CD15, CD24, CD44, and CD133 surface expression were evaluated on CSF floating tumor cells. The tumor-associated leukocyte population was also characterized. Despite a low absolute cell number (8 cell/μl, range 1-86), the flow cytometry characterization was successfully conducted in all the samples. Syndecan-1 and MUC-1 overexpression was documented on BC cells in all the samples analyzed; CD44, CD24, CD15, and CD133 in 77%, 75%, 70%, and 45% of cases, respectively. A strong syndecan-1 and MUC-1 expression was also documented by immunohistochemistry on primary breast cancer tissues, performed in four patients. The CSF tumor population was flanked by T lymphocytes, with a different immunophenotype between the CSF and peripheral blood samples (P ≤ 0.02). Flow cytometry can be successfully employed for solid tumor LM characterization even in CSF samples with low cell count. This in vivo study documents that CSF floating BC cells overexpress prognostic and putative cancer stem cell biomarkers related to tumor invasiveness, potentially representing a molecular target for circulating tumor cell detection and LM treatment monitoring, as well as a primary target for innovative treatment strategies. The T lymphocyte infiltration, documented in all CSF samples, suggests a possible involvement of the CNS lymphatic system in both lymphoid and cancer cell migration into and out of the meninges, supporting the extension of a new form of cellular immunotherapy to LM. Due to the small number of cases, validation on large cohorts of patients are warranted to confirm these findings and to evaluate the impact and value of these results for diagnosis and management of LM.

Durability and Intelligent Nondestructive Evaluation of Adhesive Composite Joints

DTIC Science & Technology

2000-09-22

PERFORMING ORGANIZATION NAME(S) AND ADDRESS( ES ) 8. PERFORMING ORGANIZATION University of Nebraska-Lincoln, Research Grants REPORTNUMBER & Contracts Office...Lincoln, NE 68588-0430 9. SPONSORING / MONrrORLNG AGENCY NAIME(S) AND ADDRESS( ES ) 10. SPONSORING / MONITORING AGENCY REPORT NUMBER * AFOSR 801 North...An MTS 10 MT load cell was used to measure loads. The tests were performed with a Satec spherical alignment coupling attached to the top grip. Acoustic

Antitumor Activity and Mechanism of a Reverse Transcriptase Inhibitor, Dapivirine, in Glioblastoma.

PubMed

Liu, Weiwen; Song, Xian-Lu; Zhao, Shan-Chao; He, Minyi; Wang, Hai; Chen, Ziyang; Xiang, Wei; Yi, Guozhong; Qi, Songtao; Liu, Yawei

2018-01-01

Dapivirine is one of reverse transcriptase inhibitors (RTIs). It is the prototype of diarylpyrimidines (DAPY), formerly known as TMC120 or DAPY R147681 (IUPAC name: 4- [[4-(2, 4, 6-trimethylphenyl) amino]-2-pyrimidinyl] amino]-benzonitrile; CAS no.244767-67-7). The purpose of this study is to investigate the antitumor activity of dapivirine, one of the RTIs, on U87 glioblastoma (GBM) cells in vitro and in vivo . U87 GBM cells were cultured and treated with or without dapivirine. Cell viability was evaluated by CCK-8 (Cell Counting Kit 8, CCK-8) assay; apoptosis was analyzed by flow cytometry; cell migration was evaluated by Boyden Chamber assay; Western blotting was performed to detect proteins related to apoptosis, epithelial-to-mesenchymal transition and autophagy. PathScan intracellular signaling array kit was used to detect important and well-characterized signaling molecules. Tumor xenograft model in nude mice was used to evaluate the antitumorigenic effect in vivo . Dapivirine weakened proliferation of glioma cells and induced the apoptosis of U87 glioblastoma cells. Furthermore, dapivirine regulated autophagy and induced Akt, Bad and SAPK/JNK activations. Moreover, the inhibition of glioma cell growth by dapivirine was also observed in nude mice in vivo . In summary, in our study dapivirine exposure induces stress, resulting in JNK and PI3K/Akt pathway activation through diminished inhibition of the apoptosis and autophagy cascade in U87 GBM cells, which inhibits cell growth in vitro and in vivo .

Performance of Transuranic-Loaded Fully Ceramic Micro-Encapsulated Fuel in LWRs Final Report, Including Void Reactivity Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael A. Pope; R. Sonat Sen; Brian Boer

2011-09-01

The current focus of the Deep Burn Project is on once-through burning of transuranics (TRU) in light-water reactors (LWRs). The fuel form is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the tri-isotropic (TRISO) fuel particle design from high-temperature reactor technology. In the Deep Burn LWR (DB-LWR) concept, these fuel particles are pressed into compacts using SiC matrix material and loaded into fuel pins for use in conventional LWRs. The TRU loading comes from the spent fuel of a conventional LWR after 5 years of cooling. Unit cell and assembly calculations have been performed using the DRAGON-4 code tomore » assess the physics attributes of TRU-only FCM fuel in an LWR lattice. Depletion calculations assuming an infinite lattice condition were performed with calculations of various reactivity coefficients performed at each step. Unit cells and assemblies containing typical UO2 and mixed oxide (MOX) fuel were analyzed in the same way to provide a baseline against which to compare the TRU-only FCM fuel. Then, assembly calculations were performed evaluating the performance of heterogeneous arrangements of TRU-only FCM fuel pins along with UO2 pins.« less

Single cell performance studies on the FE/CR Redox Energy Storage System using mixed reactant solutions at elevated temperature

NASA Technical Reports Server (NTRS)

Gahn, R. F.; Hagedorn, N. H.; Ling, J. S.

1983-01-01

Experimental studies in a 14.5 sq cm single cell system using mixed reactant solutions at 65 C are described. Systems were tested under isothermal conditions, i.e., reactants and the cell were at the same temperature. Charging and discharging performance were evaluated by measuring watt-hour and coulombic efficiencies, voltage-current relationships, hydrogen evolution and membrane resistivity. Watt-hour efficiencies ranged from 86 percent at 43 ma/sq cm to 75 percent at 129 ma/sq cm with corresponding coulombic efficiencies of 92 percent and 97 percent, respectively. Hydrogen evolution was less than 1 percent of the charge coulumbic capacity during charge-discharge cycling. Bismuth amd bismuth-lead catalyzed chromium electrodes maintained reversible performance and low hydrogen evolution under normal and adverse cycling conditions. Reblending of the anode and cathode solutions was successfully demonstrated to compensate for osmotic volume changes. Improved performance was obtained with mixed reactant systems in comparison to the unmixed reactant systems. Previously announced in STAR as N83-25042

Battery Thermal Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keyser, Matthew A

The operating temperature is critical in achieving the right balance between performance, cost, and life for both Li-ion batteries and ultracapacitors. The chemistries of advanced energy-storage devices - such as lithium-based batteries - are very sensitive to operating temperature. High temperatures degrade batteries faster while low temperatures decrease their power and capacity, affecting vehicle range, performance, and cost. Understanding heat generation in battery systems - from the individual cells within a module, to the inter-connects between the cells, and across the entire battery system - is imperative for designing effective thermal-management systems and battery packs. At NREL, we have developedmore » unique capabilities to measure the thermal properties of cells and evaluate thermal performance of battery packs (air or liquid cooled). We also use our electro-thermal finite element models to analyze the thermal performance of battery systems in order to aid battery developers with improved thermal designs. NREL's tools are used to meet the weight, life, cost, and volume goals set by the U.S. Department of Energy for electric drive vehicles.« less

Production of oncolytic adenovirus and human mesenchymal stem cells in a single-use, Vertical-Wheel bioreactor system: Impact of bioreactor design on performance of microcarrier-based cell culture processes.

PubMed

Sousa, Marcos F Q; Silva, Marta M; Giroux, Daniel; Hashimura, Yas; Wesselschmidt, Robin; Lee, Brian; Roldão, António; Carrondo, Manuel J T; Alves, Paula M; Serra, Margarida

2015-01-01

Anchorage-dependent cell cultures are used for the production of viruses, viral vectors, and vaccines, as well as for various cell therapies and tissue engineering applications. Most of these applications currently rely on planar technologies for the generation of biological products. However, as new cell therapy product candidates move from clinical trials towards potential commercialization, planar platforms have proven to be inadequate to meet large-scale manufacturing demand. Therefore, a new scalable platform for culturing anchorage-dependent cells at high cell volumetric concentrations is urgently needed. One promising solution is to grow cells on microcarriers suspended in single-use bioreactors. Toward this goal, a novel bioreactor system utilizing an innovative Vertical-Wheel™ technology was evaluated for its potential to support scalable cell culture process development. Two anchorage-dependent human cell types were used: human lung carcinoma cells (A549 cell line) and human bone marrow-derived mesenchymal stem cells (hMSC). Key hydrodynamic parameters such as power input, mixing time, Kolmogorov length scale, and shear stress were estimated. The performance of Vertical-Wheel bioreactors (PBS-VW) was then evaluated for A549 cell growth and oncolytic adenovirus type 5 production as well as for hMSC expansion. Regarding the first cell model, higher cell growth and number of infectious viruses per cell were achieved when compared with stirred tank (ST) bioreactors. For the hMSC model, although higher percentages of proliferative cells could be reached in the PBS-VW compared with ST bioreactors, no significant differences in the cell volumetric concentration and expansion factor were observed. Noteworthy, the hMSC population generated in the PBS-VW showed a significantly lower percentage of apoptotic cells as well as reduced levels of HLA-DR positive cells. Overall, these results showed that process transfer from ST bioreactor to PBS-VW, and scale-up was successfully carried out for two different microcarrier-based cell cultures. Ultimately, the data herein generated demonstrate the potential of Vertical-Wheel bioreactors as a new scalable biomanufacturing platform for microcarrier-based cell cultures of complex biopharmaceuticals. © 2015 American Institute of Chemical Engineers.

Measuring the lactate-to-creatine ratio via 1H NMR spectroscopy can be used to noninvasively evaluate apoptosis in glioma cells after X-ray irradiation.

PubMed

Li, Hongxia; Cui, Yi; Li, Fuyan; Shi, Wenqi; Gao, Wenjing; Wang, Xiao; Zeng, Qingshi

2018-01-01

Radiotherapy is among the commonly applied treatment options for glioma, which is one of the most common types of primary brain tumor. To evaluate the effect of radiotherapy noninvasively, it is vital for oncologists to monitor the effects of X-ray irradiation on glioma cells. Preliminary research had showed that PKC-ι expression correlates with tumor cell apoptosis induced by X-ray irradiation. It is also believed that the lactate-to-creatine (Lac/Cr) ratio can be used as a biomarker to evaluate apoptosis in glioma cells after X-ray irradiation. In this study, we evaluated the relationships between the Lac/Cr ratio, apoptotic rate, and protein kinase C iota (PKC-ι) expression in glioma cells. Cells of the glioma cell lines C6 and U251 were randomly divided into 4 groups, with every group exposed to X-ray irradiation at 0, 1, 5, 10 and 15 Gy. Single cell gel electrophoresis (SCGE) was conducted to evaluate the DNA damage. Flow cytometry was performed to measure the cell cycle blockage and apoptotic rates. Western blot analysis was used to detect the phosphorylated PKC-ι (p-PKC-ι) level. 1 H NMR spectroscopy was employed to determine the Lac/Cr ratio. The DNA damage increased in a radiation dose-dependent manner ( p  < 0.05). With the increase in X-ray irradiation, the apoptotic rate also increased (C6, p  < 0.01; U251, p  < 0.05), and the p-PKC-ι level decreased (C6, p  < 0.01; U251, p  < 0.05). The p-PKC-ι level negatively correlated with apoptosis, whereas the Lac/Cr ratio positively correlated with the p-PKC-ι level. The Lac/Cr ratio decreases with an increase in X-ray irradiation and thus can be used as a biomarker to reflect the effects of X-ray irradiation in glioma cells.

General Electric 20-ampere hour nickel-cadmium battery

NASA Technical Reports Server (NTRS)

Kirsch, W. W.

1974-01-01

The interaction, effect, and controllability of the performance parameters of the General Electric 20-ampere-hour, 24-cell nickel cadmium battery are investigated. The battery was cycled under simulated orbit conditions. The acquired data was analyzed and evaluated in terms of battery parameters and performance characteristics. Conclusions and tests results are presented along with recommendations for further study.

Molecular Engineering toward Stabilized Interface: An Electrolyte Additive for High-Performance Li-Ion Battery

DOE PAGES

Zhang, Lu; Huang, Jinhua; Youssef, Kyrrilos; ...

2014-10-31

A novel electrolyte additive, 3-oxabicyclo[3.1.0]hexane-2,4-dione (OHD), has been discovered and evaluated in Li- 1.1(Mn 1/3Ni 1/3Co 1/3) 0.9O 2/graphite cells under elevated temperature. When an appropriate amount of OHD is used, the cell capacity retention is improved from 60% (Gen 2 electrolyte alone) to 82% (Gen 2 electrolyte plus OHD) after 200 cycles with no obvious impedance increase. The amount of OHD added is the key to achieving the superior cell performance. In conclusion, the effect of OHD additive was investigated by means of electrochemical analysis, fourier transform infrared spectroscopy, scanning electron microscopy, and density functional theory computation.

Laser-zone growth in a Ribbon-To-Ribbon, RTR, process silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Gurtler, R. W.; Baghdadi, A.

1977-01-01

A ribbon-to-ribbon process was used for routine growth of samples for analysis and fabrication into solar cells. One lot of solar cells was completely evaluated: ribbon solar cell efficiencies averaged 9.23% with a highest efficiency of 11.7%. Spherical reflectors have demonstrated significant improvements in laser silicon coupling efficiencies. Material analyses were performed including silicon photovoltage and open circuit photovoltage diffusion length measurements, crystal morphology studies, modulus of rupture measurements, and annealing/gettering studies. An initial economic analysis was performed indicating that ribbon-to-ribbon add-on costs of $.10/watt might be expected in the early 1980's.

Numerical and Experimental Investigation on a Thermo-Photovoltaic Module for Higher Efficiency Energy Generation

NASA Astrophysics Data System (ADS)

Karami-Lakeh, Hossein; Hosseini-Abardeh, Reza; Kaatuzian, Hassan

2017-05-01

One major problem of solar cells is the decrease in efficiency due to an increase in temperature when operating under constant irradiation of solar energy. The combination of solar cell and a thermoelectric generator is one of the methods proposed to solve this problem. In this paper, the performance of thermo-photovoltaic system is studied experimentally as well as through numerical simulation. In the experimental part, design, manufacture and test of a novel thermo-photovoltaic system assembly are presented. Results of the assembled system showed that with reduction of one degree (Centigrade) in the temperature of solar cell under investigation, and about 0.2 % increase in the efficiency will be obtained in comparison with given efficiency at that specified temperature. The solar cell in a hybrid-assembled system under two cooling conditions (air cooling and water cooling) obtained an efficiency of 8 % and 9.5 %, respectively, while the efficiency of a single cell under the same radiation condition was 6 %. In numerical simulation part, photo-thermoelectric performance of system was analyzed. Two methods for evaluation of thermoelectric performance were used: average properties and finite element method. Results of simulation also demonstrate an increase in solar cell efficiency in the combined system in comparison with that of the single cell configuration.

Silicon and Carbon Nanocomposite Spheres with Enhanced Electrochemical Performance for Full Cell Lithium Ion Batteries

PubMed Central

Wang, Wei; Favors, Zachary; Li, Changling; Liu, Chueh; Ye, Rachel; Fu, Chengyin; Bozhilov, Krassimir; Guo, Juchen; Ozkan, Mihrimah; Ozkan, Cengiz S.

2017-01-01

Herein, facile synthesis of monodisperse silicon and carbon nanocomposite spheres (MSNSs) is achieved via a simple and scalable surface-protected magnesiothermic reduction with subsequent chemical vapor deposition (CVD) process. Li-ion batteries (LIBs) were fabricated to test the utility of MSNSs as an anode material. LIB anodes based on MSNSs demonstrate a high reversible capacity of 3207 mAh g−1, superior rate performance, and excellent cycling stability. Furthermore, the performance of full cell LIBs was evaluated by using MSNS anode and a LiCoO2 cathode with practical electrode loadings. The MSNS/LiCoO2 full cell demonstrates high gravimetric energy density in the order of 850 Wh L−1 with excellent cycling stability. This work shows a proof of concept of the use of monodisperse Si and C nanocomposite spheres toward practical lithium-ion battery applications. PMID:28322285

Improvement of IFNγ ELISPOT Performance Following Overnight Resting of Frozen PBMC Samples Confirmed Through Rigorous Statistical Analysis

PubMed Central

Santos, Radleigh; Buying, Alcinette; Sabri, Nazila; Yu, John; Gringeri, Anthony; Bender, James; Janetzki, Sylvia; Pinilla, Clemencia; Judkowski, Valeria A.

2014-01-01

Immune monitoring of functional responses is a fundamental parameter to establish correlates of protection in clinical trials evaluating vaccines and therapies to boost antigen-specific responses. The IFNγ ELISPOT assay is a well-standardized and validated method for the determination of functional IFNγ-producing T-cells in peripheral blood mononuclear cells (PBMC); however, its performance greatly depends on the quality and integrity of the cryopreserved PBMC. Here, we investigate the effect of overnight (ON) resting of the PBMC on the detection of CD8-restricted peptide-specific responses by IFNγ ELISPOT. The study used PBMC from healthy donors to evaluate the CD8 T-cell response to five pooled or individual HLA-A2 viral peptides. The results were analyzed using a modification of the existing distribution free resampling (DFR) recommended for the analysis of ELISPOT data to ensure the most rigorous possible standard of significance. The results of the study demonstrate that ON resting of PBMC samples prior to IFNγ ELISPOT increases both the magnitude and the statistical significance of the responses. In addition, a comparison of the results with a 13-day preculture of PBMC with the peptides before testing demonstrates that ON resting is sufficient for the efficient evaluation of immune functioning. PMID:25546016

Cytotoxicity and Initial Biocompatibility of Endodontic Biomaterials (MTA and Biodentine™) Used as Root-End Filling Materials.

PubMed

Escobar-García, Diana María; Aguirre-López, Eva; Méndez-González, Verónica; Pozos-Guillén, Amaury

2016-01-01

Objective. The aim of this study was to evaluate the cytotoxicity and cellular adhesion of Mineral Trioxide Aggregate (MTA) and Biodentine (BD) on periodontal ligament fibroblasts (PDL). Methods. PDL cells were obtained from nonerupted third molars and cultured; MTS cellular profusion test was carried out in two groups: MTA and BD, with respective controls at different time periods. Also, the LIVE/DEAD assay was performed at 24 h. For evaluation of cellular adhesion, immunocytochemistry was conducted to discern the expression of Integrin β1 and Vinculin at 12 h and 24 h. Statistical analysis was performed by the Kruskal-Wallis and Mann-Whitney U tests. Results. MTA and BD exhibited living cells up to 7 days. More expressions of Integrin β1 and Vinculin were demonstrated in the control group, followed by BD and MTA, which also showed cellular loss and morphological changes. There was a significant difference in the experimental groups cultured for 5 and 7 days compared with the control, but there was no significant statistical difference between both cements. Conclusions. Neither material was cytotoxic during the time evaluated. There was an increase of cell adhesion through the expression of focal contacts observed in the case of BD, followed by MTA, but not significantly.

Differential gene expression profiling of human adipose stem cells differentiating into smooth muscle-like cells by TGFβ1/BMP4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elçin, Ayşe Eser; Parmaksiz, Mahmut; Dogan, Arin

Regenerative repair of the vascular system is challenging from the perspectives of translational medicine and tissue engineering. There are fundamental hurdles in front of creating bioartificial arteries, which involve recaputilation of the three-layered structure under laboratory settings. Obtaining and maintaining smooth muscle characteristics is an important limitation, as the transdifferentiated cells fail to display mature phenotype. This study aims to shed light on the smooth muscle differentiation of human adipose stem cells (hASCs). To this end, we first acquired hASCs from lipoaspirate samples. Upon characterization, the cells were induced to differentiate into smooth muscle (SM)-like cells using a variety ofmore » inducer combinations. Among all, TGFβ1/BMP4 combination had the highest differentiation efficiency, based on immunohistochemical analyses. hSM-like cell samples were compared to hASCs and to the positive control, human coronary artery-smooth muscle cells (hCA-SMCs) through gene transcription profiling. Microarray findings revealed the activation of gene groups that function in smooth muscle differentiation, signaling pathways, extracellular modeling and cell proliferation. Our results underline the effectiveness of the growth factors and suggest some potential variables for detecting the SM-like cell characteristics. Evidence in transcriptome level was used to evaluate the TGFβ1/BMP4 combination as a previously unexplored effector for the smooth muscle differentiation of adipose stem cells. - Highlights: • Human adipose stem cells (hASCs) were isolated, characterized and cultured. • Growth factor combinations were evaluated for their effectiveness in differentiation using IHC. • hASCs were differentiated into smooth muscle (SM)-like cells using TGF-β1 and BMP4 combination. • Microarray analysis was performed for hASCs, SM-like cells and coronary artery-SMCs. • Microarray data was used to perform hierarchical clustering and interpretation of activated pathways.« less

Characterization of deliberately nickel-doped silicon wafers and solar cells. [microstructure, electrical properties, and energy conversion efficiency

NASA Technical Reports Server (NTRS)

Salama, A. M.

1980-01-01

Microstructural and electrical evaluation tests were performed on nickel-doped p-type silicon wafers before and after solar cell fabrication. The concentration levels of nickel in silicon were 5 x 10 to the 14th power, 4 x 10 to the 15th power, and 8 x 10 to the 15th power atoms/cu cm. It was found that nickel precipitated out during the growth process in all three ingots. Clumps of precipitates, some of which exhibited star shape, were present at different depths. If the clumps are distributed at depths approximately 20 micron apart and if they are larger than 10 micron in diameter, degradation occurs in solar cell electrical properties and cell conversion efficiency. The larger the size of the precipitate clump, the greater the degradation in solar cell efficiency. A large grain boundary around the cell effective area acted as a gettering center for the precipitates and impurities and caused improvement in solar cell efficiency. Details of the evaluation test results are given.

In vitro evaluation of (99m)Tc-EDDA/tricine-HYNIC-Q-Litorin in gastrin-releasing peptide receptor positive tumor cell lines.

PubMed

Yurt Lambrecht, Fatma; Durkan, Kübra; Ozgür, Aykut; Gündüz, Cumhur; Avcı, Cığır Biray; Susluer, Sunde Yılmaz

2013-05-01

Bombesin and its derivatives exhibit a high affinity for gastrin-releasing peptide receptor (GRPr), which is over-expressed in a variety of human cancers (prostate, pancreatic, lung, etc.). The aim of this study was to investigate the in vitro potential of the hydrazinonicotinamide (HYNIC)-Q-Litorin. (99m)Tc labeling was performed by using different co-ligands: tricine and ethylenediamine diacetic acid (EDDA). The radiochemical stability of radiolabeled peptide conjugates was checked at room temperature and in cysteine solution up to 24 h. The in vitro cell uptake of (99m)Tc-EDDA-HYNIC-Q-Litorin and (99m)Tc-tricine-HYNIC-Q-Litorin were evaluated on pancreatic tumor and control cell lines. Optimum specific activity and incubation time were determined for all the cell lines. The results showed that the cell uptake of the radiolabeled peptide conjugates in tumor cell lines were higher than in the control cell line. The findings of this study indicated the need for further development of in vivo study as a radiopharmaceutical for pancreatic tumor imaging.

Generation of Mouse Lung Epithelial Cells.

PubMed

Kasinski, Andrea L; Slack, Frank J

2013-08-05

Although in vivo models are excellent for assessing various facets of whole organism physiology, pathology, and overall response to treatments, evaluating basic cellular functions, and molecular events in mammalian model systems is challenging. It is therefore advantageous to perform these studies in a refined and less costly setting. One approach involves utilizing cells derived from the model under evaluation. The approach to generate such cells varies based on the cell of origin and often the genetics of the cell. Here we describe the steps involved in generating epithelial cells from the lungs of Kras LSL-G12D/+ ; p53 LSL-R172/+ mice (Kasinski and Slack, 2012). These mice develop aggressive lung adenocarcinoma following cre-recombinase dependent removal of a stop cassette in the transgenes and subsequent expression of Kra -G12D and p53 R172 . While this protocol may be useful for the generation of epithelial lines from other genetic backgrounds, it should be noted that the Kras; p53 cell line generated here is capable of proliferating in culture without any additional genetic manipulation that is often needed for less aggressive backgrounds.

Ultrasensitive automated RNA in situ hybridization for kappa and lambda light chain mRNA detects B-cell clonality in tissue biopsies with performance comparable or superior to flow cytometry.

PubMed

Guo, Ling; Wang, Zhen; Anderson, Courtney M; Doolittle, Emerald; Kernag, Siobhan; Cotta, Claudiu V; Ondrejka, Sarah L; Ma, Xiao-Jun; Cook, James R

2018-03-01

The assessment of B-cell clonality is a critical component of the evaluation of suspected lymphoproliferative disorders, but analysis from formalin-fixed, paraffin-embedded tissues can be challenging if fresh tissue is not available for flow cytometry. Immunohistochemical and conventional bright field in situ hybridization stains for kappa and lambda are effective for evaluation of plasma cells but are often insufficiently sensitive to detect the much lower abundance of light chains present in B-cells. We describe an ultrasensitive RNA in situ hybridization assay that has been adapted for use on an automated immunohistochemistry platform and compare results with flow cytometry in 203 consecutive tissues and 104 consecutive bone marrows. Overall, in 203 tissue biopsies, RNA in situ hybridization identified light chain-restricted B-cells in 85 (42%) vs 58 (29%) by flow cytometry. Within 83 B-cell non-Hodgkin lymphomas, RNA in situ hybridization identified restricted B-cells in 74 (89%) vs 56 (67%) by flow cytometry. B-cell clonality could be evaluated in only 23/104 (22%) bone marrow cases owing to poor RNA preservation, but evaluable cases showed 91% concordance with flow cytometry. RNA in situ hybridization allowed for recognition of biclonal/composite lymphomas not identified by flow cytometry and highlighted unexpected findings, such as coexpression of kappa and lambda RNA in 2 cases and the presence of lambda light chain RNA in a T lymphoblastic lymphoma. Automated RNA in situ hybridization showed excellent interobserver reproducibility for manual evaluation (average K=0.92), and an automated image analysis system showed high concordance (97%) with manual evaluation. Automated RNA in situ hybridization staining, which can be adopted on commonly utilized immunohistochemistry instruments, allows for the interpretation of clonality in the context of the morphological features in formalin-fixed, paraffin-embedded tissues with a clinical sensitivity similar or superior to flow cytometry.

Ultrasensitive Automated RNA in situ Hybridization for Kappa and Lambda Light Chain mRNA Detects B-cell Clonality in Tissue Biopsies with Performance Comparable or Superior to Flow Cytometry

PubMed Central

Guo, Ling; Wang, Zhen; Anderson, Courtney M.; Doolittle, Emerald; Kernag, Siobhan; Cotta, Claudiu V.; Ondrejka, Sarah L.; Ma, Xiao-Jun; Cook, James R.

2017-01-01

The assessment of B-cell clonality is a critical component of the evaluation of suspected lymphoproliferative disorders, but analysis from formalin fixed paraffin embedded tissues can be challenging if fresh tissue is not available for flow cytometry. Immunohistochemical and conventional bright field in situ hybridization stains for kappa and lambda are effective for evaluation of plasma cells, but are often insufficiently sensitive to detect the much lower abundance of light chains present in B cells. We describe an ultrasensitive RNA in situ hybridization assay which has been adapted for use on an automated immunohistochemistry platform and compare results with flow cytometry in 203 consecutive tissues and 104 consecutive bone marrows. Overall, in 203 tissue biopsies, RNA in situ hybridization identified light chain restricted B-cells in 85 (42%) vs. 58 (29%) by flow cytometry. Within 83 B-cell non-Hodgkin lymphomas, RNA in situ hybridization identified a restricted B-cells in 74 (89%) vs. 56 (67%) by flow cytometry. B-cell clonality could be evaluated in only 23/104 (22%) bone marrow cases due to poor RNA preservation, but evaluable cases showed 91% concordance with flow cytometry. RNA in situ hybridization allowed for recognition of biclonal/composite lymphomas not identified by flow cytometry, and highlighted unexpected findings, such as coexpression of kappa and lambda RNA in 2 cases and the presence of lambda light chain RNA in a T lymphoblastic lymphoma. Automated RNA in situ hybridization showed excellent interobserver reproducibility for manual evaluation (average K=0.92), and an automated image analysis system showed high concordance (97%) with manual evaluation. Automated RNA in situ hybridization staining, which can be adopted on commonly utilized immunohistochemistry instruments, allows for the interpretation of clonality in the context of the morphologic features in formalin fixed, paraffin embedded tissues with a clinical sensitivity similar or superior to flow cytometry. PMID:29052600

Performance and Safety Evaluations of Moli Spinel Lithium-Ion Cells

NASA Technical Reports Server (NTRS)

Jevarajan, Judith; Cook, Joseph S.; Collins, Jacob

2005-01-01

The current spike obtained during the hard external short test is small (8.2 A) compared to those obtained from a LiCoO2 system (60 to 80 A). The simulated internal short did not result in an explosion or fire as it does with the LiCoO2 systems. The temperatures obtained during the heat-to-vent test are not very high compared to the cobaltate cells. The cells do not retain capacity very well, but the capacity can be recovered with cycling. The spinel cells are much safer under abuse conditions than the lithium-ion cells with other transition metal oxides.

Aerospace Nickel-cadmium Cell Verification

NASA Technical Reports Server (NTRS)

Manzo, Michelle A.; Strawn, D. Michael; Hall, Stephen W.

2001-01-01

During the early years of satellites, NASA successfully flew "NASA-Standard" nickel-cadmium (Ni-Cd) cells manufactured by GE/Gates/SAFF on a variety of spacecraft. In 1992 a NASA Battery Review Board determined that the strategy of a NASA Standard Cell and Battery Specification and the accompanying NASA control of a standard manufacturing control document (MCD) for Ni-Cd cells and batteries was unwarranted. As a result of that determination, standards were abandoned and the use of cells other than the NASA Standard was required. In order to gain insight into the performance and characteristics of the various aerospace Ni-Cd products available, tasks were initiated within the NASA Aerospace Flight Battery Systems Program that involved the procurement and testing of representative aerospace Ni-Cd cell designs. A standard set of test conditions was established in order to provide similar information about the products from various vendors. The objective of this testing was to provide independent verification of representative commercial flight cells available in the marketplace today. This paper will provide a summary of the verification tests run on cells from various manufacturers: Sanyo 35 Ampere-hour (Ali) standard and 35 Ali advanced Ni-Cd cells, SAFr 50 Ah Ni-Cd cells and Eagle-Picher 21 Ali Magnum and 21 Ali Super Ni-CdTM cells from Eagle-Picher were put through a full evaluation. A limited number of 18 and 55 Ali cells from Acme Electric were also tested to provide an initial evaluation of the Acme aerospace cell designs. Additionally, 35 Ali aerospace design Ni-MH cells from Sanyo were evaluated under the standard conditions established for this program. Ile test program is essentially complete. The cell design parameters, the verification test plan and the details of the test result will be discussed.

Qualitative and quantitative evaluation of a local lymph node assay based on ex vivo interleukin-2 production.

PubMed

Azam, Philippe; Peiffer, Jean-Luc; Ourlin, Jean-Claude; Bonnet, Pierre-Antoine; Tissier, Marie-Hélène; Vian, Laurence; Fabre, Isabelle

2005-01-15

The local lymph node assay (LLNA) is a regular method for the detection of sensitizing chemicals in mice which measures the incorporation of tritiated thymidine in lymph node cells. We have evaluated an alternative to this method based on the interleukin-2 (IL-2) production of lymph node cells. At the mRNA level, no change in the IL-2 gene expression level was detected by real-time PCR analysis. At the protein level, various experimental conditions were checked in order to improve the irritant versus sensitizer discrimination with a restricted set of prototypic compounds. In particular, the use of phytohemagglutinin A (PHA) in an ex vivo cell culture step showed an improvement of both signal and discrimination. In these optimised conditions, a panel of irritants and potency-graded sensitizers was used to assess the performance of the modified method. IFN-gamma production was used as a positive control. For each compound, a dose-response was performed and stimulation indexes (SI) were determined. Effective concentrations (EC) for each sensitizers were then extracted and compared to the literature data of the regular LLNA. The IL-2-based LLNA showed similar performances at both qualitative and quantitative levels compared to regular LLNA.

Cellular uptake and ex vivo urothelial penetration by oligodeoxynucleotides for optimizing treatment of transitional cell carcinoma.

PubMed

Bolenz, Christian; Trojan, Lutz; Gabriel, Ute; Honeck, Patrick; Wendt-Nordahl, Gunnar; Schaaf, Axel; Alken, Peter; Michel, Maurice Stephan

2008-10-01

To evaluate cellular uptake and urothelial penetration of oligodeoxynucleotides (ODNs) in transitional cell carcinoma (TCC) cell lines and in a porcine ex vivo model, respectively. A panel of human TCC cell lines (RT 112, HT 1197 and UM-UC3) were exposed tofluorescein-labeled ODNs. Transfection rates were assessed byfluorescence microscopy and fluorescence-activated cell sorting (FACS). Intravesical treatment with ODNs was performed in a porcine ex vivo model. Urothelial penetration was evaluated using fluorescence microscopy of cryosections. Treatment with ODNs provided transfection rates of at least 96.8% of TCC cells, irrespective of use of a transfection agent. Effective urothelial penetration by ODNs was detected when compared with controls (p = 0.0325). The addition of a liposomal transfection agent significantly increased the penetration depth, allowing affection of deep urothelial cell layers (p = 0.0082). High transfection rates of ODNs can be achieved in TCC cells. Urothelial penetration of ODNs was observed down to the deepest cell layers when a transfection agent is added, suggesting a high potential for complementing the chemoresection effects on residual tumor areas during intravesical therapy of non-muscle-invasive TCC.

Optimization of polymer electrolyte membrane fuel cell flow channels using a genetic algorithm

NASA Astrophysics Data System (ADS)

Catlin, Glenn; Advani, Suresh G.; Prasad, Ajay K.

The design of the flow channels in PEM fuel cells directly impacts the transport of reactant gases to the electrodes and affects cell performance. This paper presents results from a study to optimize the geometry of the flow channels in a PEM fuel cell. The optimization process implements a genetic algorithm to rapidly converge on the channel geometry that provides the highest net power output from the cell. In addition, this work implements a method for the automatic generation of parameterized channel domains that are evaluated for performance using a commercial computational fluid dynamics package from ANSYS. The software package includes GAMBIT as the solid modeling and meshing software, the solver FLUENT, and a PEMFC Add-on Module capable of modeling the relevant physical and electrochemical mechanisms that describe PEM fuel cell operation. The result of the optimization process is a set of optimal channel geometry values for the single-serpentine channel configuration. The performance of the optimal geometry is contrasted with a sub-optimal one by comparing contour plots of current density, oxygen and hydrogen concentration. In addition, the role of convective bypass in bringing fresh reactant to the catalyst layer is examined in detail. The convergence to the optimal geometry is confirmed by a bracketing study which compares the performance of the best individual to those of its neighbors with adjacent parameter values.

Visual acuity, refractive error, and endothelial cell density 6 and 12 months after deep lamellar endothelial keratoplasty.

PubMed

Fillmore, Parley D; Sutphin, John E; Goins, Kenneth M

2010-06-01

To report the visual acuity, refractive outcome, and endothelial cell density (ECD) up to 1 year after deep lamellar endothelial keratoplasty (DLEK) in a large prospective series. Eighty-six DLEK procedures were performed and evaluated in a prospective interventional case series. Subgroup analysis was performed to compare results from large-incision (9 mm) DLEK (n = 7), small-incision (5-8 mm) DLEK (n = 70), and penetrating keratoplasty (PKP) conversion (n = 9). Outcome measures included best-corrected visual acuity (BCVA), manifest refraction, corneal topographic astigmatism, and ECD. The percentage of eyes that achieved a BCVA of 20/40 or better after DLEK was 55% at 6 months, increasing to 61% at 1 year. Topographic astigmatism and spherical equivalent were not significantly different than preoperative measurements up to 1 year after DLEK (P > 0.05). An endothelial cell loss of 40% at 6 months and 48% by 1 year was observed. The mean ECD after DLEK was 1831 +/- 472 cells per square millimeter at 6 months and 1569 +/- 601 cells per square millimeter at 12 months. When evaluated by incision size, the ECD was better at 2066 +/- 558 cells per square millimeter with a 9-mm incision compared with only 1516 +/- 585 cells per square millimeter with a smaller incision at 1 year, although this did not reach significance (P = 0.075). The endothelial cell loss after penetrating keratoplasty conversion was similar to that in the large-incision group (P > 0.05). DLEK provides good visual acuity (> or =20/40) for the majority of patients at 1 year with stable refractive error compared with baseline. Refractive stability was observed with both large- and small-incision DLEKs; however, worrisome endothelial cell loss was observed, especially with a small-incision technique.

Comparative study of autophagy inhibition by 3MA and CQ on Cytarabine‑induced death of leukaemia cells.

PubMed

Palmeira dos Santos, Caroline; Pereira, Gustavo J S; Barbosa, Christiano M V; Jurkiewicz, Aron; Smaili, Soraya S; Bincoletto, Claudia

2014-06-01

As the molecular mechanisms of Cytarabine,one of the most important drugs used in the leukaemia’s treatment, are only partially understood and the role of autophagy on leukaemia development and treatment is only recently being investigated, in this study, by using Chloroquine (CQ) and 3-methyladenine (3MA) as autophagy inhibitors, we aim to evaluate the contribution of an autophagic mechanism to Cytarabine (AraC)-induced death of HL60 leukaemia cells. Trypan blue exclusion and AnnexinV/PI assays were used to evaluate HL60 cell death under AraC treatment in the presence or absence of 3MA and CQ. Western blotting and immunofluorescence experiments were performed to show the involvement of apoptosis and autophagy protein expressions. Phenotypic characterization of HL60-treated cells was performed by using immunophenotyping. Clonogenic assays were applied to analyse clonal function of HL60-treated cells. We observed that although autophagy inhibition by 3MA, but not CQ, increased the death of HL60 AraC cells after 24 h of treatment, no significant differences between AraC and AraC + 3MA-treated groups were observed by using clonogenic assay. In addition, increased number of immature (CD34(+)/CD38(−)Lin(−/low)) HL60 cells was found in AraC and AraC-3MA groups when compared with control untreated cells. Although AraC anti-leukaemia effects could be potentiated by 3MA autophagy inhibition after 24 h of exposure, leukaemia cell resistance, the main causes of treatment failure, is also promoted by autophagy initial stage impairment by 3MA, denoting the complex role of autophagy in leukaemia cells’ response to chemotherapy.

Mechanisms of vasculogenesis in 3D fibrin matrices mediated by the interaction of adipose-derived stem cells and endothelial cells.

PubMed

Rohringer, Sabrina; Hofbauer, Pablo; Schneider, Karl H; Husa, Anna-Maria; Feichtinger, Georg; Peterbauer-Scherb, Anja; Redl, Heinz; Holnthoner, Wolfgang

2014-10-01

Vascularization of tissue-engineered constructs is essential to provide sufficient nutrient supply and hemostasis after implantation into target sites. Co-cultures of adipose-derived stem cells (ASC) with outgrowth endothelial cells (OEC) in fibrin gels were shown to provide an effective possibility to induce vasculogenesis in vitro. However, the mechanisms of the interaction between these two cell types remain unclear so far. The aim of this study was to evaluate differences of direct and indirect stimulation of ASC-induced vasculogenesis, the influence of ASC on network stabilization and molecular mechanisms involved in vascular structure formation. Endothelial cells (EC) were embedded in fibrin gels either containing non-coated or ASC-coated microcarrier beads as well as ASC alone. Moreover, EC-seeded constructs incubated with ASC-conditioned medium were used in addition to constructs with ASC seeded on top. Vascular network formation was visualized by green fluorescent protein expressing cells or immunostaining for CD31 and quantified. RT-qPCR of cells derived from co-cultures in fibrin was performed to evaluate changes in the expression of EC marker genes during the first week of culture. Moreover, angiogenesis-related protein levels were measured by performing angiogenesis proteome profiler arrays. The results demonstrate that proximity of endothelial cells and ASC is required for network formation and ASC stabilize EC networks by developing pericyte characteristics. We further showed that ASC induce controlled vessel growth by secreting pro-angiogenic and regulatory proteins. This study reveals angiogenic protein profiles involved in EC/ASC interactions in fibrin matrices and confirms the usability of OEC/ASC co-cultures for autologous vascular tissue engineering.

Flow cytometric DNA analysis of cirrhotic liver cells in patients with hepatocellular carcinoma can provide a new prognostic factor.

PubMed

Ruà, S; Comino, A; Fruttero, A; Torchio, P; Bouzari, H; Taraglio, S; Torchio, B; Capussotti, L

1996-09-15

DNA flow cytometry of hepatocellular carcinoma (HCC) cells has been investigated in many studies, but, to the best of our knowledge, there are no data on DNA analysis of cirrhotic parenchyma around the HCC. In this study, cell kinetics and ploidy of parenchymal cells around HCC were performed to ascertain if this would predict the possibility of recurrence in the cirrhotic areas. The DNA content of 93 cases of HCC and of cirrhotic liver around the tumor nodules was analyzed by flow cytometry. Ploidy and proliferative index of HCC and cirrhotic liver were compared with macroscopic, histologic, and clinical features of each case and linked with the behavior of these tumors. Survival curves were assessed according to the Kaplan-Meier method. A multivariate analysis based on Cox proportional hazards regression model was performed on cases of diploid cirrhosis cells in which the S-phase fraction was evaluable. The univariate analysis of survival suggested significant roles for age, number of intrahepatic nodules, Edmondson-Steiner's classification, portal invasion, vascular invasion, presence of necrosis, hepatitis B surface antigen, alpha-feto-protein, Child's score, ploidy, and S-phase fraction of HCC cells. The DNA analysis of the cirrhotic cells showed that polyploidy was dramatically reduced in patients with HCC, compared with normal hepatocytes, and aneuploid clones were present among diploid cells. High S-phase fraction of cirrhotic cells and Child-Pugh classification were the strongest independent parameters affecting the tumor behavior in this study. The results of this study suggest that S-phase fraction of cirrhotic liver parenchyma may be employed as a new parameter in the prognostic evaluation of HCC patients.

Ibrutinib, a Bruton's tyrosine kinase inhibitor, exhibits antitumoral activity and induces autophagy in glioblastoma.

PubMed

Wang, Jin; Liu, Xiaoyang; Hong, Yongzhi; Wang, Songtao; Chen, Pin; Gu, Aihua; Guo, Xiaoyuan; Zhao, Peng

2017-07-17

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults. Ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor, is a novel anticancer drug used for treating several types of cancers. In this study, we aimed to determine the role of ibrutinib on GBM. Cell proliferation was determined by using cell viability, colony formation, and 5-ethynyl-2'-deoxyuridine (EdU) assays. Cell cycle and cell apoptosis were analyzed by flow cytometry. Cell migratory ability was evaluated by wound healing assays and trans-well migration assays. ATG7 expression was knocked-down by transfection with Atg7-specific small interfering RNA. Overexpression of active Akt protein was achieved by transfecting the cells with a plasmid expressing constitutively active Akt (CA-Akt). Transmission electron microscopy was performed to examine the formation of autophagosomes in cells. Immunofluorescence and western blot analyses were used to analyze protein expression. Tumor xenografts in nude mice and immunohistochemistry were performed to evaluate the effect of ibrutinib on tumor growth in vivo. Ibrutinib inhibited cellular proliferation and migration, and induced apoptosis and autophagy in LN229 and U87 cells. Overexpression of the active Akt protein decreased ibrutinib-induced autophagy, while inhibiting Akt by LY294002 treatment enhanced ibrutinib-induced autophagy. Specific inhibition of autophagy by 3-methyladenine (3MA) or Atg7 targeting with small interfering RNA (si-Atg7) enhanced the anti-GBM effect of ibrutinib in vitro and in vivo. Our results indicate that ibrutinib exerts a profound antitumor effect and induces autophagy through Akt/mTOR signaling pathway in GBM cells. Autophagy inhibition promotes the antitumor activity of ibrutinib in GBM. Our findings provide important insights into the action of an anticancer agent combining with autophagy inhibitor for malignant glioma.

The 2004 NASA Aerospace Battery Workshop

NASA Technical Reports Server (NTRS)

2006-01-01

Topics covered include: Super NiCd(TradeMark) Energy Storage for Gravity Probe-B Relativity Mission; Hubble Space Telescope 2004 Battery Update; The Development of Hermetically Sealed Aerospace Nickel-Metal Hydride Cell; Serial Charging Test on High Capacity Li-Ion Cells for the Orbiter Advanced Hydraulic Power System; Cell Equalization of Lithium-Ion Cells; The Long-Term Performance of Small-Cell Batteries Without Cell-Balancing Electronics; Identification and Treatment of Lithium Battery Cell Imbalance under Flight Conditions; Battery Control Boards for Li-Ion Batteries on Mars Exploration Rovers; Cell Over Voltage Protection and Balancing Circuit of the Lithium-Ion Battery; Lithium-Ion Battery Electronics for Aerospace Applications; Lithium-Ion Cell Charge Control Unit; Lithium Ion Battery Cell Bypass Circuit Test Results at the U.S. Naval Research Laboratory; High Capacity Battery Cell By-Pass Switches: High Current Pulse Testing of Lithium-Ion; Battery By-Pass Switches to Verify Their Ability to Withstand Short-Circuits; Incorporation of Physics-Based, Spatially-Resolved Battery Models into System Simulations; A Monte Carlo Model for Li-Ion Battery Life Projections; Thermal Behavior of Large Lithium-Ion Cells; Thermal Imaging of Aerospace Battery Cells; High Rate Designed 50 Ah Li-Ion Cell for LEO Applications; Evaluation of Corrosion Behavior in Aerospace Lithium-Ion Cells; Performance of AEA 80 Ah Battery Under GEO Profile; LEO Li-Ion Battery Testing; A Review of the Feasibility Investigation of Commercial Laminated Lithium-Ion Polymer Cells for Space Applications; Lithium-Ion Verification Test Program; Panasonic Small Cell Testing for AHPS; Lithium-Ion Small Cell Battery Shorting Study; Low-Earth-Orbit and Geosynchronous-Earth-Orbit Testing of 80 Ah Batteries under Real-Time Profiles; Update on Development of Lithium-Ion Cells for Space Applications at JAXA; Foreign Comparative Technology: Launch Vehicle Battery Cell Testing; 20V, 40 Ah Lithium Ion Polymer Battery for the Spacesuit; Low Temperature Life-Cycle Testing of a Lithium-Ion Battery for Low-Earth-Orbiting Spacecraft; and Evaluation of the Effects of DoD and Charge Rate on a LEO Optimized 50 Ah Li-Ion Aerospace Cell.

Formulation and evaluation of biodegradable nanoparticles for the oral delivery of fenretinide.

PubMed

Graves, Richard A; Ledet, Grace A; Glotser, Elena Y; Mitchner, Demaurian M; Bostanian, Levon A; Mandal, Tarun K

2015-08-30

Fenretinide is an anticancer drug with low water solubility and poor bioavailability. The goal of this study was to develop biodegradable polymeric nanoparticles of fenretinide with the intent of increasing its apparent aqueous solubility and intestinal permeability. Three biodegradable polymers were investigated for this purpose: two different poly lactide-co-glycolide (PLGA) polymers, one acid terminated and one ester terminated, and one poly lactide-co-glycolide/polyethylene glycol (PLGA/PEG) diblock copolymer. Nanoparticles were obtained by using an emulsification solvent evaporation technique. The formulations were characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and particle size analysis. Dissolution studies and Caco-2 cell permeation studies were also carried out for all formulations. Ultra high performance liquid chromatography coupled with mass spectrometry (UPLC/MS) and ultraviolet detection was used for the quantitative determination of fenretinide. Drug loading and the type of polymer affected the nanoparticles' physical properties, drug release rate, and cell permeability. While the acid terminated PLGA nanoparticles performed the best in drug release, the ester terminated PLGA nanoparticles performed the best in the Caco-2 cell permeability assays. The PLGA/PEG copolymer nanoparticles performed better than the formulations with ester terminated PLGA in terms of drug release but had the poorest performance in terms of cell permeation. All three categories of formulations performed better than the drug alone in both drug release and cell permeation studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Back surface reflectors for solar cells

NASA Technical Reports Server (NTRS)

Chai, A. T.

1980-01-01

Sample solar cells were fabricated to study the effects of various back surface reflectors on the device performance. They are typical 50 micrometers thick, space quality, silicon solar cells except for variations of the back contact configuration. The back surfaces of the sample cells are polished to a mirror like finish, and have either conventional full contacts or grid finger contacts. Measurements and evaluation of various metallic back surface reflectors, as well as cells with total internal reflection, are presented. Results indicate that back surface reflectors formed using a grid finger back contact are more effective reflectors than cells with full back metallization and that Au, Ag, or Cu are better back surface reflector metals than Al.

OMEGA System Performance Assessment and Coverage Evaluation (PACE) Workstation Design and Implementation. Volume 2

DTIC Science & Technology

1991-02-15

picked, Ce11Pop" .xmonth, CeliPcpUpA .hour’ . Phase kND $80) = 0 ELSE IF (stationinfol36’ [stations. picked, CellIP-- CpA .n=nh, CeSUP pP.hour . Phiase...CellGrid, irt (322,24. 281,314, RightCeliGridAction, ShoCe11~ta, DcNot-hingPr-oc, bJii ne (lfepnIi lfs t.Xj05,efIghplit. Y4, 60,16,white, blak , black...8217.Hilite(oc,yy); with CellPI~p do begin if (SubCells (Hcnth,Hr] .X < (Get~4axX - RightsideStatsA .width - SubCellIs (Month, Hour) Width - SubCellP~ cpA

Metabolic Abnormalities Detected in Phase II Evaluation of Doxycycline in Dogs with Multicentric B-Cell Lymphoma

PubMed Central

Hume, Kelly R.; Sylvester, Skylar R.; Borlle, Lucia; Balkman, Cheryl E.; McCleary-Wheeler, Angela L.; Pulvino, Mary; Casulo, Carla; Zhao, Jiyong

2018-01-01

Doxycycline has antiproliferative effects in human lymphoma cells and in murine xenografts. We hypothesized that doxycycline would decrease canine lymphoma cell viability and prospectively evaluated its clinical tolerability in client-owned dogs with spontaneous, nodal, multicentric, substage a, B-cell lymphoma, not previously treated with chemotherapy. Treatment duration ranged from 1 to 8 weeks (median and mean, 3 weeks). Dogs were treated with either 10 (n = 6) or 7.5 (n = 7) mg/kg by mouth twice daily. One dog had a stable disease for 6 weeks. No complete or partial tumor responses were observed. Five dogs developed grade 3 and/or 4 metabolic abnormalities suggestive of hepatopathy with elevations in bilirubin, ALT, ALP, and/or AST. To evaluate the absorption of oral doxycycline in our study population, serum concentrations in 10 treated dogs were determined using liquid chromatography tandem mass spectrometry. Serum levels were variable and ranged from 3.6 to 16.6 µg/ml (median, 7.6 µg/ml; mean, 8.8 µg/ml). To evaluate the effect of doxycycline on canine lymphoma cell viability in vitro, trypan blue exclusion assay was performed on canine B-cell lymphoma cell lines (17-71 and CLBL) and primary B-cell lymphoma cells from the nodal tissue of four dogs. A doxycycline concentration of 6 µg/ml decreased canine lymphoma cell viability by 80%, compared to matched, untreated, control cells (mixed model analysis, p < 0.0001; Wilcoxon signed rank test, p = 0.0313). Although the short-term administration of oral doxycycline is not associated with the remission of canine lymphoma, combination therapy may be worthwhile if future research determines that doxycycline can alter cell survival pathways in canine lymphoma cells. Due to the potential for metabolic abnormalities, close monitoring is recommended with the use of this drug in tumor-bearing dogs. Additional research is needed to assess the tolerability of chronic doxycycline therapy. PMID:29536017

Determinants of Practice Patterns and Quality Gaps in Lung Cancer Staging and Diagnosis

PubMed Central

Niu, Jiangong; Elting, Linda S.; Buchholz, Thomas A.; Giordano, Sharon H.

2014-01-01

Background: Guidelines recommend mediastinal lymph node sampling as the first invasive diagnostic procedure in patients with suspected lung cancer with mediastinal lymphadenopathy without distant metastases. Methods: Patients were a retrospective cohort of 15,316 patients with lung cancer with regional spread without metastatic disease in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) or Texas Cancer Registry Medicare-linked databases. Patients were categorized based on the sequencing of invasive diagnostic tests performed: (1) evaluation consistent with guidelines, mediastinal sampling done first; (2) evaluation inconsistent with guidelines, non-small cell lung cancer (NSCLC) present, mediastinal sampling performed but not as part of the first invasive test; (3) evaluation inconsistent with guidelines, NSCLC present, mediastinal sampling never done; and (4) evaluation inconsistent with guidelines, small cell lung cancer. The primary outcome was whether guideline-consistent care was delivered. Secondary outcomes included whether patients with NSCLC ever had mediastinal sampling and use of transbronchial needle aspiration (TBNA) among pulmonologists. Results: Only 21% of patients had a diagnostic evaluation consistent with guidelines. Only 56% of patients with NSCLC had mediastinal sampling prior to treatment. There was significant regional variability in guideline-consistent care (range, 12%-29%). Guideline-consistent care was associated with lower patient age, metropolitan areas, and if the physician ordering or performing the test was male, trained in the United States, had seen more patients with lung cancer, and was a pulmonologist or thoracic surgeon who had graduated more recently. More recent pulmonary graduates were also more likely to perform TBNA (P < .001). Conclusions: Guideline-consistent care varied regionally and was associated with physician-level factors, suggesting that a lack of effective physician training may be contributing to the quality gaps observed. PMID:24202651

Rapid diagnosis of primary ciliary dyskinesia: cell culture and soft computing analysis.

PubMed

Pifferi, Massimo; Bush, Andrew; Montemurro, Francesca; Pioggia, Giovanni; Piras, Martina; Tartarisco, Gennaro; Di Cicco, Maria; Chinellato, Iolanda; Cangiotti, Angela M; Boner, Attilio L

2013-04-01

Diagnosis of primary ciliary dyskinesia (PCD) sometimes requires repeated nasal brushing to exclude secondary ciliary alterations. Our aim was to evaluate whether the use of a new method of nasal epithelial cell culture can speed PCD diagnosis in doubtful cases and to identify which are the most informative parameters by means of a multilayer artificial neural network (ANN). A cross-sectional study was performed in patients with suspected PCD. All patients underwent nasal brushing for ciliary motion analysis, ultrastructural assessment and evaluation of ciliary function after ciliogenesis in culture by ANN. 151 subjects were studied. A diagnostic suspension cell culture was obtained in 117 nasal brushings. A diagnosis of PCD was made in 36 subjects (29 of whom were children). In nine out of the 36 patients the diagnosis was made only after a second brushing, because of equivocal results of both tests at first examination. In each of these subjects diagnosis of PCD was confirmed by cell culture results. Cell culture in suspension evaluated by means of ANN allows the separation of PCD from secondary ciliary dyskinesia patients after only 5 days of culture and allows diagnosis to be reached in doubtful cases, thus avoiding the necessity of a second sample.

Evaluation of the udder health status in subclinical mastitis affected dairy cows through bacteriological culture, somatic cell count and thermographic imaging.

PubMed

Bortolami, A; Fiore, E; Gianesella, M; Corrò, M; Catania, S; Morgante, M

2015-01-01

Subclinical mastitis in dairy cows is a big economic loss for farmers. The monitoring of subclinical mastitis is usually performed through Somatic Cell Count (SCC) in farm but there is the need of new diagnostic systems able to quickly identify cows affected by subclinical infections of the udder. The aim of this study was to evaluate the potential application of thermographic imaging compared to SCC and bacteriological culture for infection detection in cow affected by subclinical mastitis and possibly to discriminate between different pathogens. In this study we evaluated the udder health status of 98 Holstein Friesian dairy cows with high SCC in 4 farms. From each cow a sample of milk was collected from all the functional quarters and submitted to bacteriological culture, SCC and Mycoplasma spp. culture. A thermographic image was taken from each functional udder quarter and nipple. Pearson's correlations and Analysis of Variance were performed in order to evaluate the different diagnostic techniques. The most frequent pathogen isolated was Staphylococcus aureus followed by Coagulase Negative Staphylococci (CNS), Streptococcus uberis, Streptococcus agalactiae and others. The Somatic Cell Score (SCS) was able to discriminate (p<0.05) cows positive for a pathogen from cows negative at the bacteriological culture except for cows with infection caused by CNS. Infrared thermography was correlated to SCS (p<0.05) but was not able to discriminate between positive and negative cows. Thermographic imaging seems to be promising in evaluating the inflammation status of cows affected by subclinical mastitis but seems to have a poor diagnostic value.

Estimation and uncertainty analysis of dose response in an inter-laboratory experiment

NASA Astrophysics Data System (ADS)

Toman, Blaza; Rösslein, Matthias; Elliott, John T.; Petersen, Elijah J.

2016-02-01

An inter-laboratory experiment for the evaluation of toxic effects of NH2-polystyrene nanoparticles on living human cancer cells was performed with five participating laboratories. Previously published results from nanocytoxicity assays are often contradictory, mostly due to challenges related to producing a reliable cytotoxicity assay protocol for use with nanomaterials. Specific challenges include reproducibility preparing nanoparticle dispersions, biological variability from testing living cell lines, and the potential for nano-related interference effects. In this experiment, such challenges were addressed by developing a detailed experimental protocol and using a specially designed 96-well plate layout which incorporated a range of control measurements to assess multiple factors such as nanomaterial interference, pipetting accuracy, cell seeding density, and instrument performance. Detailed data analysis of these control measurements showed that good control of the experiments was attained by all participants in most cases. The main measurement objective of the study was the estimation of a dose response relationship between concentration of the nanoparticles and metabolic activity of the living cells, under several experimental conditions. The dose curve estimation was achieved by imbedding a three parameter logistic curve in a three level Bayesian hierarchical model, accounting for uncertainty due to all known experimental conditions as well as between laboratory variability in a top-down manner. Computation was performed using Markov Chain Monte Carlo methods. The fit of the model was evaluated using Bayesian posterior predictive probabilities and found to be satisfactory.

Dimethylaminoethanol affects the viability of human cultured fibroblasts.

PubMed

Gragnani, Alfredo; Giannoccaro, Fabiana Bocci; Sobral, Christiane S; Moraes, A A F; França, Jeronimo P; Ferreira, A T; Ferreira, Lydia Masako

2007-01-01

In clinical practice, dimethylaminoethanol (DMAE) has been used in the fight against wrinkles and flaccidity in the cervicofacial region. The firming action of DMAE is explained by the fact that its molecule, considered to be a precursor of acetylcholine, alters muscle contraction. However, no experimental studies have confirmed this theory. Because the actual mechanism of DMAE action was not defined and there were no references in the literature regarding its direct action on fibroblasts, this study was performed to evaluate the direct action of DMAE on cultured human fibroblasts. Human fibroblasts obtained from discarded fragments of total skin from patients undergoing plastic or reconstructive surgical procedures performed within the Plastic Surgery Division at the Federal University of São Paulo were used for this study. The explant technique was used. The culture medium was supplemented with different concentrations of DMAE on the fourth cell passage, and the cell proliferation rate, cytosolic calcium levels, and cell cycle were evaluated. Statistical analysis was performed using analysis of variance (ANOVA) followed by a Newman-Keuls test for multiple comparisons. A decrease in fibroblast proliferation was associated with an increase in DMAE concentration. A longer treatment time with trypsin was required for the groups treated with DMAE in a dose-dependent manner. In the presence of DMAE, cytosolic calcium increased in a dose-dependent manner. Apoptosis also increased in groups treated with DMAE. Dimethylaminoethanol reduced the proliferation of fibroblasts, increased cytosolic calcium, and changed the cell cycle, causing an increase in apoptosis in cultured human fibroblasts.

Evaluations of candidate encapsulation designs and materials for low-cost silicon photovoltaic arrays

NASA Technical Reports Server (NTRS)

Gaines, G. B.; Carmichael, D. C.; Sliemers, F. A.; Brockway, M. C.; Bunk, A. R.; Nance, G. P.

1978-01-01

Three encapsulation designs for silicon photovoltaic arrays based on cells with silk-screened Ag metallization have been evaluated: transparent polymeric coatings over cells laminated between two films or sheets of polymeric materials; cells adhesively bonded to a glass cover with a polymer pottant and a glass or other substrate component. Silicone and acrylic coatings were assessed, together with acrylic sheet, 0.635 mm fiberglass-reinforced polyester sheet, 0.102 mm polycarbonate/acrylic dual-layer film, 0.127 mm fluorocarbon film, soda-lime glass, borosilicate glass, low-iron glass, and several adhesives. The encapsulation materials were characterized by light transmittance measurements, determination of moisture barrier properties and bond strengths, and by the performance of cells before and after encapsulation. Silicon and acrylic coatings provided inadequate protection. Acrylic and fluorocarbon films displayed good weatherability and acceptable optical transmittance. Borosilicate, low-iron and soda-lime-float glasses were found to be acceptable candidate encapsulants for most environments.

Evaluating In Vitro DNA Damage Using Comet Assay.

PubMed

Lu, Yanxin; Liu, Yang; Yang, Chunzhang

2017-10-11

DNA damage is a common phenomenon for each cell during its lifespan, and is defined as an alteration of the chemical structure of genomic DNA. Cancer therapies, such as radio- and chemotherapy, introduce enormous amount of additional DNA damage, leading to cell cycle arrest and apoptosis to limit cancer progression. Quantitative assessment of DNA damage during experimental cancer therapy is a key step to justify the effectiveness of a genotoxic agent. In this study, we focus on a single cell electrophoresis assay, also known as the comet assay, which can quantify single and double-strand DNA breaks in vitro. The comet assay is a DNA damage quantification method that is efficient and easy to perform, and has low time/budget demands and high reproducibility. Here, we highlight the utility of the comet assay for a preclinical study by evaluating the genotoxic effect of olaparib/temozolomide combination therapy to U251 glioma cells.

Bacterial cell identification in differential interference contrast microscopy images.

PubMed

Obara, Boguslaw; Roberts, Mark A J; Armitage, Judith P; Grau, Vicente

2013-04-23

Microscopy image segmentation lays the foundation for shape analysis, motion tracking, and classification of biological objects. Despite its importance, automated segmentation remains challenging for several widely used non-fluorescence, interference-based microscopy imaging modalities. For example in differential interference contrast microscopy which plays an important role in modern bacterial cell biology. Therefore, new revolutions in the field require the development of tools, technologies and work-flows to extract and exploit information from interference-based imaging data so as to achieve new fundamental biological insights and understanding. We have developed and evaluated a high-throughput image analysis and processing approach to detect and characterize bacterial cells and chemotaxis proteins. Its performance was evaluated using differential interference contrast and fluorescence microscopy images of Rhodobacter sphaeroides. Results demonstrate that the proposed approach provides a fast and robust method for detection and analysis of spatial relationship between bacterial cells and their chemotaxis proteins.

Laccase/AuAg Hybrid Glucose Microfludic Fuel Cell

NASA Astrophysics Data System (ADS)

López-González, B.; Cuevas-Muñiz, F. M.; Guerra-Balcázar, M.; Déctor, A.; Arjona, N.; Ledesma-García, J.; Arriaga, L. G.

2013-12-01

In this work a hybrid microfluidic fuel cell was fabricated and evaluated with a AuAg/C bimetallic material for the anode and an enzymatic cathode. The cathodic catalyst was prepared adsorbing laccase and ABTS on Vulcan carbon (Lac-ABTS/C). This material was characterized by FTIR-ATR, the results shows the presence of absorption bands corresponding to the amide bounds. The electrochemical evaluation for the materials consisted in cyclic voltammetry (CV). The glucose electrooxidation reaction in AuAg/C occurs around - 0.3 V vs. NHE. Both electrocatalytic materials were placed in a microfluidic fuel cell. The fuel cell was fed with PBS pH 5 oxygen saturated solution in the cathodic compartment and 5 mM glucose + 0.3 M KOH in the anodic side. Several polarization curves were performed and the maximum power density obtained was 0.3 mWcm-2 .

Evaluation of Intraocular Inflammation with Laser Flare Photometry in Behçet Uveitis.

PubMed

Yalcindag, Fatime Nilufer; Bingol Kiziltunc, Pinar; Savku, Esra

2017-02-01

To evaluate the association between intraocular inflammation and laser flare photometry measurements in Behçet disease. In total, 45 patients were included in the study. The retrospective chart reviews of patients were performed. The flare levels were compared with the grade of anterior chamber cells, the presence of vitreous cells, the complications of uveitis, and fluorescein angiography scores. The attack group had higher flare intensity; the flare levels were higher in both groups compared with the values of healthy controls. The flare levels were related to the grade of the anterior chamber cells, the presence of vitreous cells and the fluorescein angiography scores. Patients with optic atrophy and/or maculopathy also had higher values. Higher flare values were correlated with poor vision. Laser flare photometry may reduce the necessity of fluorescein angiography in monitoring subclinical inflammation and may be an indicator of posterior segment activity when fluorescein angiography is not applicable.

Characterization of the 20-Ah nickel-cadmium cell used for energy storage on the Orbiting Astronomical Observatory

NASA Technical Reports Server (NTRS)

Ford, F. E.

1972-01-01

Tests were conducted on 20-Ah sealed nickel cadmium cells to evaluate initial and long-term performance at various charge rates, temperatures and voltage-control levels. An average ampere-hour recharge of 103 percent per orbit at 13 C was able to maintain cell capacity; required watt-hour recharge on an orbital basis was 8 to 10 percent greater than required ampere-hour recharge. Cells exhibited an early life burn-in characteristic. A discharge after periods of repetitive cycling yielded two voltage plateaus which were temporarily eliminated by the discharge.

Modification of Aspergillus niger by conducting polymer, Polypyrrole, and the evaluation of electrochemical properties of modified cells.

PubMed

Apetrei, Roxana-Mihaela; Carac, Geta; Bahrim, Gabriela; Ramanaviciene, Almira; Ramanavicius, Arunas

2018-06-01

The enhancement of bioelectrochemical properties of microorganism by in situ formation of conducting polymer within the cell structures (e.g. cell wall) was performed. The synthesis of polypyrrole (Ppy) within fungi (Aspergillus niger) cells was achieved. Two different Aspergillus niger strains were selected due to their ability to produce glucose oxidase, which initiated the Ppy formation through products of enzymatic reaction. The evolution of Ppy structural features was investigated by absorption spectroscopy, cyclic voltammetry and Fourier transform infrared spectroscopy. Copyright © 2018 Elsevier B.V. All rights reserved.

Alginate as a cell culture substrate for growth and differentiation of human retinal pigment epithelial cells.

PubMed

Heidari, Razeih; Soheili, Zahra-Soheila; Samiei, Shahram; Ahmadieh, Hamid; Davari, Maliheh; Nazemroaya, Fatemeh; Bagheri, Abouzar; Deezagi, Abdolkhalegh

2015-03-01

The purpose of this study was to evaluate retinal pigment epithelium (RPE) cells' behavior in alginate beads that establish 3D environment for cellular growth and mimic extracellular matrix versus the conventional 2D monolayer culture. RPE cells were encapsulated in alginate beads by dripping alginate cell suspension into CaCl2 solution. Beads were suspended in three different media including Dulbecco's modified Eagle's medium (DMEM)/F12 alone, DMEM/F12 supplemented with 10 % fetal bovine serum (FBS), and DMEM/F12 supplemented with 30 % human amniotic fluid (HAF). RPE cells were cultivated on polystyrene under the same conditions as controls. Cell phenotype, cell proliferation, cell death, and MTT assay, immunocytochemistry, and real-time RT-PCR were performed to evaluate the effect of alginate on RPE cells characteristics and integrity. RPE cells can survive and proliferate in alginate matrixes. Immunocytochemistry analysis exhibited Nestin, RPE65, and cytokeratin expressions in a reasonable number of cultured cells in alginate beads. Real-time PCR data demonstrated high levels of Nestin, CHX10, RPE65, and tyrosinase gene expressions in RPE cells immobilized in alginate when compared to 2D monolayer culture systems. The results suggest that alginate can be used as a reliable scaffold for maintenance of RPE cells' integrity and in vitro propagation of human retinal progenitor cells for cell replacement therapies in retinal diseases.

Evaluation of nucleated red blood cell count by Sysmex XE-2100 in patients with thalassaemia or sickle cell anaemia and in neonates.

PubMed

Buoro, Sabrina; Vavassori, Mauro; Pipitone, Silvia; Benegiamo, Anna; Lochis, Eleonora; Fumagalli, Sabina; Falanga, Anna; Marchetti, Marina; Crippa, Alberto; Ottomano, Cosimo; Lippi, Giuseppe

2015-10-01

Current haematology analysers have variable sensitivity and accuracy for counting nucleated red blood cells in samples with low values and in all those conditions characterised by altered sensitivity of red blood cells to the lysing process, such as in beta-thalassaemia or sickle-cell diseases and in neonates. The aim of our study was to evaluate the performance of the automated analyser XE-2100 at counting nucleated red blood cells in the above-mentioned three categories of subjects with potentially altered red blood cell lysis sensitivity and yet a need for accurate nucleated red blood cell counts. We measured nucleated red blood cell count by XE-2100 in peripheral blood samples of 187 subjects comprising 55 patients with beta-thalassaemia (40 major and 15 traits), 26 sickle-cell patients, 56 neonates and 50 normal subject. Results were compared with those obtained by optical microscopy. Agreement between average values of the two methods was estimated by means of Pearson's correlation and bias analysis, whereas diagnostic accuracy was estimated by analysis of receiver operating characteristic curves. The comparison between the two methods showed a Pearson's correlation of 0.99 (95% CI; 0.98-0.99; p<0.001) and bias of -0.61 (95% CI, -1.5-0.3). The area under the curve of the nucleated red blood cell count in all samples was 0.98 (95% CI, 0.96-1.00; p<0.001). Sub-analysis revealed an area under curve of 0.99 (95% CI, 0.98-1.00; p<0.001) for patients with thalassaemia, 0.94 (95% CI, 0.85-1.00; p<0.001) for patients with sickle cell anaemia, and 1.00 (95% CI, 1.0-1.0) for neonates. XE-2100 has excellent performance for nucleated red blood cell counting, especially in critical populations such as patients with haemoglobinopathies and neonates.

Characteristic findings of cervical Papanicolaou tests from transgender patients on androgen therapy: Challenges in detecting dysplasia.

PubMed

Adkins, B D; Barlow, A B; Jack, A; Schultenover, S J; Desouki, M M; Coogan, A C; Weiss, V L

2018-02-28

The characteristic features of Papanicolaou (Pap) tests collected from female-to-male (FTM) transgender patients on androgen therapy have not been well defined in the literature. FTM transgender patients require cervical cancer screening with the same recommended frequency as cis-gender females. Dysplasia remains challenging to differentiate from atrophy. Without pertinent history, the atrophic findings in younger transgender patients can be misinterpreted as high-grade dysplasia. A review of all cervical Pap tests of transgender patients receiving androgen therapy (2010-2017) was performed. Bethesda diagnosis, cytomorphological features, HPV testing and cervical biopsy results were reviewed. Eleven transgender patients receiving androgen therapy were identified with 23 cervical Pap tests, 11 HPV tests and five cervical biopsies performed. A review of the Pap tests demonstrated: 57% negative for intraepithelial lesion; 13% unsatisfactory; 13% atypical squamous cells of undetermined significance; 13% atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion; and 4% high-grade squamous intraepithelial lesion. The rates of abnormal tests were higher than our age-matched cis-gender atrophic cohort rates of unsatisfactory (0.5%), atypical squamous cells of undetermined significance (7%), atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion (0%) and high-grade squamous intraepithelial lesion (0.5%). The cytological findings from liquid-based preparations included dispersed and clustered parabasal-type cells, scattered degenerated cells, smooth evenly dispersed chromatin, and occasional mild nuclear enlargement and irregularity. Dysplastic cells had larger nuclei, hyperchromatic clumped chromatin, and more irregular nuclear contours. The evaluation of dysplasia can be challenging on Pap tests from transgender patients on androgen therapy. The cohort evaluated had higher rates of unsatisfactory and abnormal Pap tests. Pathologists should be familiar with the distinctive cytomorphological changes in the Pap tests from patients on androgen therapy to evaluate them appropriately. © 2018 John Wiley & Sons Ltd.

Performance of PCR-based and Bioluminescent assays for mycoplasma detection.

PubMed

Falagan-Lotsch, Priscila; Lopes, Talíria Silva; Ferreira, Nívea; Balthazar, Nathália; Monteiro, Antônio M; Borojevic, Radovan; Granjeiro, José Mauro

2015-11-01

Contaminated eukaryotic cell cultures are frequently responsible for unreliable results. Regulatory entities request that cell cultures must be mycoplasma-free. Mycoplasma contamination remains a significant problem for cell cultures and may have an impact on biological analysis since they affect many cell parameters. The gold standard microbiological assay for mycoplasma detection involves laborious and time-consuming protocols. PCR-based and Bioluminescent assays have been considered for routine cell culture screening in research laboratories since they are fast, easy and sensitive. Thus, the aim of this work is to compare the performance of two popular commercial assays, PCR-based and Bioluminescent assays, by assessing the level of mycoplasma contamination in cell cultures from Rio de Janeiro Cell Bank (RJCB) and also from customers' laboratories. The results obtained by both performed assays were confirmed by scanning electron microscopy. In addition, we evaluated the limit of detection of the PCR kit under our laboratory conditions and the storage effects on mycoplasma detection in frozen cell culture supernatants. The performance of both assays for mycoplasma detection was not significantly different and they showed very good agreement. The Bioluminescent assay for mycoplasma detection was slightly more dependable than PCR-based due to the lack of inconclusive results produced by the first technique, especially considering the ability to detect mycoplasma contamination in frozen cell culture supernatants. However, cell lines should be precultured for four days or more without antibiotics to obtain safe results. On the other hand, a false negative result was obtained by using this biochemical approach. The implementation of fast and reliable mycoplasma testing methods is an important technical and regulatory issue and PCR-based and Bioluminescent assays may be good candidates. However, validation studies are needed. Copyright © 2015 Elsevier B.V. All rights reserved.

Electrochemical Characteristics of Cell Cultured Ti-Nb-Zr Alloys After Nano-Crystallized Si-HA Coating.

PubMed

Jeong, Yong-Hoon; Choe, Han-Cheol

2015-01-01

The aim of this study was to investigate the electrochemical characteristics of nano crystallized Si-HA coating on Ti-Nb-Zr alloy after human osteoblast like (HOB) cell attachment. The Ti-Nb-Zr alloy was manufactured with 35 wt.% of Nb and 10 wt.% of Zr by arc melting furnace to appropriate physical properties as biomaterials. The HA and Si-substituted coatings were prepared by electron-beam physical vapor deposition method with 0.5, 0.8 and 1.2 wt.% of Si contents, and nano aging treatment was performed 500 degrees C for 1 h. The characteristics of coating surface were analyzed by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction, respectively. To evaluate of cell attachment on cell cultured surface, the potentiodynamic test was performed on the surface using HOB cells. The results showed that the Si-HA coating surface showed higher tendency of cell attachment than that of single HA coating, corrosion resistance value was increased by dense of cell attachment.

Evaluation of the genotoxicity of Euterpe oleraceae Mart. (Arecaceae) fruit oil (açaí), in mammalian cells in vivo.

PubMed

Marques, E S; Froder, J G; Carvalho, J C T; Rosa, P C P; Perazzo, F F; Maistro, E L

2016-07-01

E. oleracea is a tropical plant from the Amazon region, with its fruit used for food, and traditionally, as an antioxidant, anti-inflammatory, hypocholesterolemic, for atherosclerotic disease, and has anticancer properties. The oil of the fruit has antidiarrheic, anti-inflammatory and antinociceptive activities, but without genotoxicity evaluation. Therefore, the aim of this study was to evaluate the genotoxic potential of E. oleracea fruit oil (EOO), in rat cells. Male Wistar rats were treated with EOO by gavage at doses of 30, 100 and 300 mg/kg, for 14 days, within a 24 h interval. The DNA damage in the leukocytes, liver, bone marrow and testicular cells, was assessed by the comet assay, and the clastogenic/aneugenic effects in the bone marrow cells, by the micronucleus test. Our phytochemicals characterization of the EOO showed the presence of vanillic, palmitic, γ-linolenic, linoleic, oleic, cinnamic, caffeic, protocatechuic, ferulic, syringic acids, and flavonoids quercetin and kaempferol rutinoside as the main constituents. Both cytogenetic tests performed showed that EOO presented no significant genotoxic effects in the analyzed cells, at the three tested doses. These results indicate that, under our experimental conditions, E. oleracea fruit oil did not reveal genetic toxicity in rat cells. Copyright © 2016. Published by Elsevier Ltd.

Small stack performance of intermediate temperature-operating solid oxide fuel cells using stainless steel interconnects and anode-supported single cell

NASA Astrophysics Data System (ADS)

Bae, Joongmyeon; Lim, Sungkwang; Jee, Hyunjin; Kim, Jung Hyun; Yoo, Young-Sung; Lee, Taehee

We are developing 1 kW class solid oxide fuel cell (SOFC) system for residential power generation (RPG) application supported by Korean Government. Anode-supported single cells with thin electrolyte layer of YSZ (yttria-stabilized zirconia) or ScSZ (scandia-stabilized zirconia) for intermediate temperature operation (650-750 °C), respectively, were fabricated and small stacks were built and evaluated. The LSCF/ScSZ/Ni-YSZ single cell showed performance of 543 mW cm -2 at 650 °C and 1680 mW cm -2 at 750 °C. The voltage of 15-cell stack based on 5 cm × 5 cm single cell (LSM/YSZ/Ni-YSZ) at 150 mW was 12.5 V in hydrogen as fuel of 120 sccm per cell at 750 °C and decreased to about 10.9 V at 500 h operation time. A 5-cell stack based on the LSCF/YSZ/FL/Ni-YSZ showed the maximum power density of 30 W, 25 W and 20 W at 750 °C, 700 °C and 650 °C, respectively. LSCF/ScSZ/Ni-YSZ-based stack showed better performance than LSCF/YSZ/Ni-YSZ stack from the experiment temperature range. I- V characteristics by using hydrogen gas and reformate gas of methane as fuel were investigated at 750 °C in LSCF/ScSZ/FL/Ni-YSZ-based 5-cell stack.

Evaluation of techniques for handling missing cost-to-charge ratios in the USA Nationwide Inpatient Sample: a simulation study.

PubMed

Yu, Tzy-Chyi; Zhou, Huanxue

2015-09-01

Evaluate performance of techniques used to handle missing cost-to-charge ratio (CCR) data in the USA Healthcare Cost and Utilization Project's Nationwide Inpatient Sample. Four techniques to replace missing CCR data were evaluated: deleting discharges with missing CCRs (complete case analysis), reweighting as recommended by Healthcare Cost and Utilization Project, reweighting by adjustment cells and hot deck imputation by adjustment cells. Bias and root mean squared error of these techniques on hospital cost were evaluated in five disease cohorts. Similar mean cost estimates would be obtained with any of the four techniques when the percentage of missing data is low (<10%). When total cost is the outcome of interest, a reweighting technique to avoid underestimation from dropping observations with missing data should be adopted.

Melanin Protects Paracoccidioides brasiliensis from the Effects of Antimicrobial Photodynamic Inhibition and Antifungal Drugs

PubMed Central

Baltazar, Ludmila Matos; Werneck, Silvia Maria Cordeiro; Soares, Betânia Maria; Ferreira, Marcus Vinicius L.; Souza, Danielle G.; Pinotti, Marcos; Santos, Daniel Assis

2015-01-01

Paracoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced by Paracoccidioides spp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated. aPI was performed using toluidine blue (TBO) as a photosensitizer and a 630-nm light-emitting diode (LED) light. The antifungals tested were itraconazole and amphotericin B. We evaluated the effects of each approach, aPI or antifungals, against nonmelanized and melanized yeast cells by performing susceptibility tests and by quantifying oxidative and nitrosative bursts during the experiments. aPI reduced nonmelanized cells by 3.0 log units and melanized cells by 1.3 log units. The results showed that melanization protects the fungal cell, probably by acting as a scavenger of nitric oxide and reactive oxygen species, but not of peroxynitrite. Melanin also increased the MICs of itraconazole and amphotericin B, and the drugs were fungicidal for nonmelanized and fungistatic for melanized yeast cells. Our study shows that melanin production by Paracoccidioides yeast cells serves a protective function during aPI and treatment with itraconazole and amphotericin B. The results suggest that melanin binds to the drugs, changing their antifungal activities, and also acts as a scavenger of reactive oxygen species and nitric oxide, but not of peroxynitrite, indicating that peroxynitrite is the main radical that is responsible for fungal death after aPI. PMID:25896704

Overexpression of miR-9 in mast cells is associated with invasive behavior and spontaneous metastasis

PubMed Central

2014-01-01

Background While microRNA (miRNA) expression is known to be altered in a variety of human malignancies contributing to cancer development and progression, the potential role of miRNA dysregulation in malignant mast cell disease has not been previously explored. The purpose of this study was to investigate the potential contribution of miRNA dysregulation to the biology of canine mast cell tumors (MCTs), a well-established spontaneous model of malignant mast cell disease. Methods We evaluated the miRNA expression profiles from biologically low-grade and biologically high-grade primary canine MCTs using real-time PCR-based TaqMan Low Density miRNA Arrays and performed real-time PCR to evaluate miR-9 expression in primary canine MCTs, malignant mast cell lines, and normal bone marrow-derived mast cells (BMMCs). Mouse mast cell lines and BMMCs were transduced with empty or pre-miR-9 expressing lentiviral constructs and cell proliferation, caspase 3/7 activity, and invasion were assessed. Transcriptional profiling of cells overexpressing miR-9 was performed using Affymetrix GeneChip Mouse Gene 2.0 ST arrays and real-time PCR was performed to validate changes in mRNA expression. Results Our data demonstrate that unique miRNA expression profiles correlate with the biological behavior of primary canine MCTs and that miR-9 expression is increased in biologically high grade canine MCTs and malignant cell lines compared to biologically low grade tumors and normal canine BMMCs. In transformed mouse malignant mast cell lines expressing either wild-type (C57) or activating (P815) KIT mutations and mouse BMMCs, miR-9 overexpression significantly enhanced invasion but had no effect on cell proliferation or apoptosis. Transcriptional profiling of normal mouse BMMCs and P815 cells possessing enforced miR-9 expression demonstrated dysregulation of several genes, including upregulation of CMA1, a protease involved in activation of matrix metalloproteases and extracellular matrix remodeling. Conclusions Our findings demonstrate that unique miRNA expression profiles correlate with the biological behavior of canine MCTs. Furthermore, dysregulation of miR-9 is associated with MCT metastasis potentially through the induction of an invasive phenotype, identifying a potentially novel pathway for therapeutic intervention. PMID:24517413

ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) PROGRAM: FUEL CELLS

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) Environmental Technology Verification (ETV) Program evaluates the performance of innovative air, water, pollution prevention and monitoring technologies that have the potential to improve human health and the environment. This techno...

Development of Ni-Ba(Zr,Y)O3 cermet anodes for direct ammonia-fueled solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Miyazaki, Kazunari; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

2017-10-01

In this study, the availability of Ni-Ba(Zr,Y)O3-δ (BZY) cermet for the anode of direct ammonia-fueled solid oxide fuel cells (SOFCs) is evaluated. In this device, the anodes need to be active for the catalytic ammonia decomposition as well as the electrochemical hydrogen oxidation. In the catalytic activity test, ammonia decomposes completely over Ni-BZY at ca. 600 °C, while higher temperature is required to accomplish the complete decomposition over the conventional SOFC anode of Ni-yttria-stabilized zirconia cermet. The high activity of Ni-BZY is attributed to the high basicity of BZY and the high resistance to hydrogen poisoning effect. The electrochemical property of Ni-BZY anode is also evaluated with the anode-supported cell of Ni-BZY|BZY|Pt at 600-700 °C with feeding ammonia or hydrogen as a fuel. Since the residence time of ammonia fuel in the thick Ni-BZY anode is long, the difference in the cell performance between two fuels is relatively small. Furthermore, it is proved that the steam concentration in the fuel strongly affects the cell performance. We find that this factor is important to satisfy the above mentioned requirements for the anode of direct ammonia-fueled SOFCs. Throughout this study, it is concluded that Ni-BZY cermet will be a promising anode.

Recent advances in the characterization of HIV-1 neutralization assays for standardized evaluation of the antibody response to infection and vaccination.

PubMed

Polonis, Victoria R; Brown, Bruce K; Rosa Borges, Andrew; Zolla-Pazner, Susan; Dimitrov, Dimiter S; Zhang, Mei-Yun; Barnett, Susan W; Ruprecht, Ruth M; Scarlatti, Gabriella; Fenyö, Eva-Maria; Montefiori, David C; McCutchan, Francine E; Michael, Nelson L

2008-06-05

In AIDS vaccine development the pendulum has swung towards a renewed emphasis on the potential role for neutralizing antibodies in a successful global vaccine. It is recognized that vaccine-induced antibody performance, as assessed in the available neutralization assays, may well serve as a "gatekeeper" for HIV-1 subunit vaccine prioritization and advancement. As a result, development of a standardized platform for reproducible measurement of neutralizing antibodies has received considerable attention. Here we review current advancements in our knowledge of the performance of different types of antibodies in a traditional primary cell neutralization assay and the newer, more standardized TZM-bl reporter cell line assay. In light of recently revealed differences (see accompanying article) in the results obtained in these two neutralization formats, parallel evaluation with both platforms should be contemplated as an interim solution until a better understanding of immune correlates of protection is achieved.

Effects of N-acetylcysteine and L-arginine in the antioxidant system of C2C12 cells.

PubMed

Da Silva, E P; Lambertucci, R H

2015-06-01

The aim of this study was to evaluate the effects of N-acetylcysteine or L-arginine in the antioxidant system of skeletal muscle cells in culture. We used C2C12 cells which were supplemented or not with N-acetylcysteine or L-arginine at different time points. Antioxidant enzymes' activities and protein expression were evaluated. Additionally, superoxide production by cytochrome c reduction method was carried out. It was observed that the supplementation with either N-acetylcysteine or L-arginine was capable to acutely reduce superoxide production (after 30 and 60 minutes). Surprisingly, N-acetylcysteine supplementation also induced an increased production of superoxide during the period of 24 hours. Moreover, both supplements were capable to improve the activity and protein expression of some antioxidants enzymes. In conclusion, we have found new evidences showing that N-acetylcysteine or L-arginine supplementation can provide some benefits to the antioxidant system of skeletal muscle cells in culture. Further studies have to be carried out to evaluate if such benefits could also occur in an in vivo model, with possible benefits for athletes' health and performance.

Analytical Study on Multi-Tier 5G Heterogeneous Small Cell Networks: Coverage Performance and Energy Efficiency.

PubMed

Xiao, Zhu; Liu, Hongjing; Havyarimana, Vincent; Li, Tong; Wang, Dong

2016-11-04

In this paper, we investigate the coverage performance and energy efficiency of multi-tier heterogeneous cellular networks (HetNets) which are composed of macrocells and different types of small cells, i.e., picocells and femtocells. By virtue of stochastic geometry tools, we model the multi-tier HetNets based on a Poisson point process (PPP) and analyze the Signal to Interference Ratio (SIR) via studying the cumulative interference from pico-tier and femto-tier. We then derive the analytical expressions of coverage probabilities in order to evaluate coverage performance in different tiers and investigate how it varies with the small cells' deployment density. By taking the fairness and user experience into consideration, we propose a disjoint channel allocation scheme and derive the system channel throughput for various tiers. Further, we formulate the energy efficiency optimization problem for multi-tier HetNets in terms of throughput performance and resource allocation fairness. To solve this problem, we devise a linear programming based approach to obtain the available area of the feasible solutions. System-level simulations demonstrate that the small cells' deployment density has a significant effect on the coverage performance and energy efficiency. Simulation results also reveal that there exits an optimal small cell base station (SBS) density ratio between pico-tier and femto-tier which can be applied to maximize the energy efficiency and at the same time enhance the system performance. Our findings provide guidance for the design of multi-tier HetNets for improving the coverage performance as well as the energy efficiency.

Depletion of regulatory T cells by anti-ICOS antibody enhances anti-tumor immunity of tumor cell vaccine in prostate cancer.

PubMed

Mo, Lijun; Chen, Qianmei; Zhang, Xinji; Shi, Xiaojun; Wei, Lili; Zheng, Dianpeng; Li, Hongwei; Gao, Jimin; Li, Jinlong; Hu, Zhiming

2017-10-13

ICOS + Treg cells exert important immunosuppressive effects in tumor immunity. We adopt a combination approach of ICOS + Treg cells depletion with tumor cell vaccine to evaluate anti-tumor immunity in mouse prostate cancer model. Streptavidin (SA)-mGM-CSF surface-modified RM-1 cells were prepared as the vaccine and the mouse subcutaneous prostate tumor model was used to evaluate the immunity. Tumor growth, flow cytometry, immunohistochemistry, immunofluorescence and enzyme linked immunosorbent assay (ELISA) were performed to evaluate the therapeutic effects. Our results demonstrated that SA-mGM-CSF vaccine was prepared successfully and tumor growth was inhibited. The tumor size in the combination group was much smaller than that in the vaccine with IgG mAb group. The portions of dendritic cells, CD8 + and CD4 + T cells in the mice blood and tumor tissues were increased after treatment with vaccine. There were more immune-suppressing Tregs infiltrated into tumor after treatment with tumor cell vaccine, and ICOS blocking could deplete the infiltrated Tregs, and T lymphocytes increased more dramatically in the combination therapy group. The concentrations of interferon-γ were increased in all vaccine group, the concentrations of Interleukin-10 and Interleukin-4 were much lower in the combination group. Our study demonstrated that ICOS blocking could deplete the tumor-infiltrated ICOS + Treg cells. Combining GM-CSF surface-modified RM-1 cell vaccine with Anti-ICOS antibody could induce better antitumor immunity than a vaccine alone. Copyright © 2017 Elsevier Ltd. All rights reserved.

Attention Deficit Hyperactivity Disorder in Children With Sickle Cell Disease Referred for an Evaluation.

PubMed

Acquazzino, Melissa A; Miller, Meghan; Myrvik, Matthew; Newby, Robert; Scott, John Paul

2017-07-01

Neuropsychological deficits, including difficulties with attention, are well described in children with sickle cell disease (SCD). Very little is known about attention deficit hyperactivity disorder (ADHD) in children with SCD. The objective of this study was to determine the proportion of ADHD in children with SCD referred for neuropsychological evaluation. This prospective, cross-sectional study included patients (age, 4 to 18 y) with SCD and completion of a neuropsychological evaluation between December 2013 and March 2016. Patients were referred for neuropsychological evaluation because of concern regarding school performance, development, and/or behavior. The diagnosis of ADHD was made by a neuropsychologist on the basis of the diagnostic criteria in the Diagnostic Statistical Manual-Fourth or Fifth Editions. ADHD medication usage rate was obtained by medical record review. Of the 89 patients with SCD referred for neuropsychological evaluation, 25% (95% confidence interval, 16%-35%) met diagnostic criteria for ADHD. Only 21% of the patients with SCD and ADHD were prescribed an ADHD medication. Our study supports routine ADHD screening in children with SCD who have poor school performance or behavioral concerns. Despite the benefits of pharmacologic treatment, the majority of patients with SCD and ADHD did not receive a medication for management of their ADHD.

Silicon solar cell process development, fabrication and analysis

NASA Technical Reports Server (NTRS)

Yoo, H. I.; Iles, P. A.; Leung, D. C.

1981-01-01

Solar cells were fabricated from EFG ribbons dendritic webs, cast ingots by heat exchanger method, and cast ingots by ubiquitous crystallization process. Baseline and other process variations were applied to fabricate solar cells. EFG ribbons grown in a carbon-containing gas atmosphere showed significant improvement in silicon quality. Baseline solar cells from dendritic webs of various runs indicated that the quality of the webs under investigation was not as good as the conventional CZ silicon, showing an average minority carrier diffusion length of about 60 um versus 120 um of CZ wafers. Detail evaluation of large cast ingots by HEM showed ingot reproducibility problems from run to run and uniformity problems of sheet quality within an ingot. Initial evaluation of the wafers prepared from the cast polycrystalline ingots by UCP suggested that the quality of the wafers from this process is considerably lower than the conventional CZ wafers. Overall performance was relatively uniform, except for a few cells which showed shunting problems caused by inclusions.

Evaluation of surgical margins according to the histological type of basal cell carcinoma.

PubMed

Godoy, Charles Antonio Pires de; Neta, Alice Lima de Oliveira; Leão, Sofia Silveira de Souza; Dantas, Raul Lima; Carvalho, Valeska Oliveira Fonseca; Silva, Samuel Freire da

2017-01-01

Basal cell carcinoma is the most common skin cancer in the world. The aim of this study was to evaluate the surgical margin of basal cell carcinoma and correlate this with its histologic subtype. A retrospective analysis of pathology laboratory records from 1990 to 2000 was performed and the following data was collected: age, sex, race, anatomical location, histological type, and state of the excision margins in 1,428 histopathological reports of basal cell carcinoma. Ages ranged from 6 to 99 years, with an average of 57. There was a slight predominance of lesions in white women patients, and the most common histological subtype was the nodular, followed by the superficial. The most common locations were in the head and neck, with highest prevalence appeared in the nose. Surgical margins revealed a lateral involvement of 20.14% and a deep involvement of 12.47%. The fibrosing basal cell carcinoma is the histological type that most often presented positive surgical margins.