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Sample records for advanced hall cells

  1. Advanced Hall Electric Propulsion for Future In-space Transportation

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; Sankovic, John M.

    2001-01-01

    The Hall thruster is an electric propulsion device used for multiple in-space applications including orbit raising, on-orbit maneuvers, and de-orbit functions. These in-space propulsion functions are currently performed by toxic hydrazine monopropellant or hydrazine derivative/nitrogen tetroxide bi-propellant thrusters. The Hall thruster operates nominally in the 1500 sec specific impulse regime. It provides greater thrust to power than conventional gridded ion engines, thus reducing trip times and operational life when compared to that technology in Earth orbit applications. The technology in the far term, by adding a second acceleration stage, has shown promise of providing over 4000s Isp, the regime of the gridded ion engine and necessary for deep space applications. The Hall thruster system consists of three parts, the thruster, the power processor, and the propellant system. The technology is operational and commercially available at the 1.5 kW power level and 5 kW application is underway. NASA is looking toward 10 kW and eventually 50 kW-class engines for ambitious space transportation applications. The former allows launch vehicle step-down for GEO missions and demanding planetary missions such as Europa Lander, while the latter allows quick all-electric propulsion LEO to GEO transfers and non-nuclear transportation human Mars missions.

  2. Particle-in-cell simulations of Hall plasma thrusters

    NASA Astrophysics Data System (ADS)

    Miranda, Rodrigo; Ferreira, Jose Leonardo; Martins, Alexandre

    2016-07-01

    Hall plasma thrusters can be modelled using particle-in-cell (PIC) simulations. In these simulations, the plasma is described by a set of equations which represent a coupled system of charged particles and electromagnetic fields. The fields are computed using a spatial grid (i.e., a discretization in space), whereas the particles can move continuously in space. Briefly, the particle and fields dynamics are computed as follows. First, forces due to electric and magnetic fields are employed to calculate the velocities and positions of particles. Next, the velocities and positions of particles are used to compute the charge and current densities at discrete positions in space. Finally, these densities are used to solve the electromagnetic field equations in the grid, which are interpolated at the position of the particles to obtain the acting forces, and restart this cycle. We will present numerical simulations using software for PIC simulations to study turbulence, wave and instabilities that arise in Hall plasma thrusters. We have sucessfully reproduced a numerical simulation of a SPT-100 Hall thruster using a two-dimensional (2D) model. In addition, we are developing a 2D model of a cylindrical Hall thruster. The results of these simulations will contribute to improve the performance of plasma thrusters to be used in Cubesats satellites currenty in development at the Plasma Laboratory at University of Brasília.

  3. Advances in cell culture

    SciTech Connect

    Maramorosch, K. )

    1987-01-01

    This book presents papers on advances in cell culture. Topics covered include: Genetic changes in the influenza viruses during growth in cultured cells; The biochemistry and genetics of mosquito cells in culture; and Tree tissue culture applications.

  4. Titanium diboride ceramic fiber composites for Hall-Heroult cells

    DOEpatents

    Besmann, Theodore M.; Lowden, Richard A.

    1990-01-01

    An improved cathode structure for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 deg. C can be used.

  5. Titanium diboride ceramic fiber composites for Hall-Heroult cells

    DOEpatents

    Besmann, T.M.; Lowden, R.A.

    1990-05-29

    An improved cathode structure is described for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 C can be used.

  6. Advanced Cell Technology, Inc.

    PubMed

    Caldwell, William M

    2007-03-01

    Advanced Cell Technology, Inc. (OTCBB: ACTC) is a biotechnology company applying novel human embryonic stem cell technologies in the emerging field of regenerative medicine. We believe that regenerative medicine has the potential to revolutionize the field by enabling scientists to produce human cells of any kind for use in a wide array of therapies.

  7. Inert Anode/Cathode Program: Fiscal Year 1986 annual report. [For Hall-Heroult cells

    SciTech Connect

    Brenden, B.B.; Davis, N.C.; Koski, O.H.; Marschman, S.C.; Pool, K.H.; Schilling, C.H.; Windisch, C.F.; Wrona, B.J.

    1987-06-01

    Purpose of the program is to develop long-lasting, energy-efficient anodes, cathodes, and ancillary equipment for Hall-Heroult cells used by the aluminum industry. The program is divided into four tasks: Inert Anode Development, Cathode Materials Evaluation, Cathode Bonding Development, and Sensor Development. To devise sensors to control the chemistry of Hall-Heroult cells using stable anodes and cathodes. This report highlights the major FY86 technical accomplishments, which are presented in the following sections: Management, Materials Development, Materials Evaluation, Thermodynamic Evaluation, Laboratory Cell Tests, Large-Scale Tests, Cathode Materials Evaluation, Cathode Bonding Development, and Sensor Development.

  8. High pressure Moissanite-anvil cells for the low temperature Hall effect measurements of oxide superconductors

    NASA Astrophysics Data System (ADS)

    Yomo, Shusuke; Tozer, Stanley

    2013-03-01

    The Hall effect was successfully measured for a single crystal of high temperature superconductor in a Moissanite-anvil clamp cell up to 5 GPa, with proper arrangement of lead wires and a sample. Zylon gasket, good in electrical insulation, worked well up to 5 GPa. The 30-40 % increase of the clamped pressure was observed during cooling to below 60 K. The appreciable pressure effect of the a-b plane Hall coefficient was observed and negative for La2 - x Srx CuO4 with x = 0.090. The result is discussed with those for sintered samples and those studied with a different pressurizing method. Thanks are due to Visiting Scientist Program, NHMFL, and NNSA grant DE-FG52-03NA00066.

  9. Ultrasensitive Mirco-Hall Detector for Enumeration and Molecular Profiling of Rare Cells

    NASA Astrophysics Data System (ADS)

    Min, Changwook; Issadore, David; Chung, Jaehoon; Shao, Huilin; Liong, Monty; Ghazani, Arezou A.; Castro, Cesar M.; Weissleder, Ralph; Lee, Hakho

    2013-03-01

    We have recently developed a miniaturized microfluidic chip-based technology, the micro-Hall detector (uHD), that can perform rapid, highly sensitive, and quantitative measurement of individual cells in unprocessed biological samples. The uHD detects the Hall voltage induced by magnetic moments of cells in-flow that have been immunomagnetically tagged with magnetic nanoparticles (MNPs) and bio-orthogonal chemistry. The entire assay is performed on a single microfluidic chip with minimal sample preparation to avoid sample loss and to simplify assay procedure, eliminating the need for any washing and purification steps, and thereby allows cellular diagnostics to be conducted in point-of-care clinical settings. We also demonstrated simultaneous detection of heterogeneous biomarkers on individual cells by targeting different cellular markers with a panel of MNPs. The quantity of each MNP type, and hence the expression level of a target biomarker in a single cell, could be obtained using the particles' distinctive magnetization properties. The clinical use of the uHD was explored by the detection of circulating tumor cells (CTCs) in whole blood of 20 ovarian cancer patients, and drug treatment efficacy was monitored in a mouse tumor model.

  10. Modeling of an advanced concept of a double stage Hall effect thruster

    SciTech Connect

    Garrigues, L.; Boniface, C.; Hagelaar, G. J. M.; Boeuf, J. P.

    2008-11-15

    We present a study of the principle and operation of a two-stage Hall effect thruster, the SPT-MAG, using a two-dimensional quasineutral hybrid model coupled with a Monte Carlo simulation of electron transport. The purpose of the two-stage design is the separation of ion production and acceleration in two separate chambers, the ionization stage and the acceleration stage, with separate control of acceleration voltage and total ionization. The originality of the SPT-MAG lies in the magnetic field configuration in the ionization chamber. Electrons are confined by this magnetic field while ions are supposed to be trapped in the electric potential well supposedly resulting from the magnetic configuration, and guided toward the acceleration stage. The acceleration stage is similar to the channel of a conventional Hall effect thruster. The purpose of this paper is to clarify the physics of the SPT-MAG and to understand the formation of the positive ion trap in the ionization chamber. Using a hybrid model and a Monte Carlo simulation we show that under typical operating conditions most of the ionization in the chamber is due to high energy electrons accelerated in the channel and entering the chamber rather than to electrons accelerated by the voltage applied in the ionization chamber. We also raise the question of the possible role of an additional emissive cathode inside the ionization chamber. The model predicts that an electric potential well guiding the ions to the channel entrance forms in the chamber only if the intermediate electrode inside the chamber is an emissive cathode (which is not the case in recent configurations used for this thruster)

  11. ARPA advanced fuel cell development

    SciTech Connect

    Dubois, L.H.

    1995-08-01

    Fuel cell technology is currently being developed at the Advanced Research Projects Agency (ARPA) for several Department of Defense applications where its inherent advantages such as environmental compatibility, high efficiency, and low noise and vibration are overwhelmingly important. These applications range from man-portable power systems of only a few watts output (e.g., for microclimate cooling and as direct battery replacements) to multimegawatt fixed base systems. The ultimate goal of the ARPA program is to develop an efficient, low-temperature fuel cell power system that operates directly on a military logistics fuel (e.g., DF-2 or JP-8). The absence of a fuel reformer will reduce the size, weight, cost, and complexity of such a unit as well as increase its reliability. In order to reach this goal, ARPA is taking a two-fold, intermediate time-frame approach to: (1) develop a viable, low-temperature proton exchange membrane (PEM) fuel cell that operates directly on a simple hydrocarbon fuel (e.g., methanol or trimethoxymethane) and (2) demonstrate a thermally integrated fuel processor/fuel cell power system operating on a military logistics fuel. This latter program involves solid oxide (SOFC), molten carbonate (MCFC), and phosphoric acid (PAFC) fuel cell technologies and concentrates on the development of efficient fuel processors, impurity scrubbers, and systems integration. A complementary program to develop high performance, light weight H{sub 2}/air PEM and SOFC fuel cell stacks is also underway. Several recent successes of these programs will be highlighted.

  12. Advanced spacecraft fuel cell systems

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1972-01-01

    The development and characteristics of advanced spacecraft fuel cell systems are discussed. The system is designed to operate on low pressure, propulsion grade hydrogen and oxygen. The specific goals are 10,000 hours of operation with refurbishment, 20 pounds per kilowatt at a sustained power of 7 KW, and 21 KW peaking capability for durations of two hours. The system rejects waste heat to the spacecraft cooling system at power levels up to 7 KW. At higher powers, the system automatically transfers to open cycle operation with overboard steam venting.

  13. Hall Effect Studies of AlGaAs Grown by Liquid-Phase Epitaxy for Tandem Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Montgomery, Kyle H.; Woodall, Jerry M.

    2014-11-01

    We report results from Hall effect studies on Al x Ga1- x As ( x = 0.23-0.24) with bandgap energies of 1.76 ± 0.01 eV grown by liquid-phase epitaxy (LPE). Room-temperature Hall measurements on unintentionally doped AlGaAs revealed p-type background doping for concentrations in the range 3.7-5.2 × 1016 cm-3. Sn, Te, Ge, and Zn-doped AlGaAs were also characterized to study the relationship between doping concentrations and the atomic fractions of the dopants in the melt. Temperature-dependent Hall measurements were performed to determine the activation energies of the four dopants. Deep donor levels (DX centers) were dominant for Sn-doped Al0.24Ga0.76As, but not for Te-doped Al0.24Ga0.76As. Comparison of the temperature-dependent Hall effect results for unintentionally and intentionally doped Al0.24Ga0.76As indicated that the impurity contributing to the p-type background doping had the same activation energy as Mg. We thus suggest a Te-doped emitter and an undoped or Ge-doped base to maximize the efficiency of Al x Ga1- x As ( x ˜ 0.23) solar cells grown by LPE.

  14. Fish T cells: recent advances through genomics

    USGS Publications Warehouse

    Laing, Kerry J.; Hansen, John D.

    2011-01-01

    This brief review is intended to provide a concise overview of the current literature concerning T cells, advances in identifying distinct T cell functional subsets, and in distinguishing effector cells from memory cells. We compare and contrast a wealth of recent progress made in T cell immunology of teleost, elasmobranch, and agnathan fish, to knowledge derived from mammalian T cell studies. From genome studies, fish clearly have most components associated with T cell function and we can speculate on the presence of putative T cell subsets, and the ability to detect their differentiation to form memory cells. Some recombinant proteins for T cell associated cytokines and antibodies for T cell surface receptors have been generated that will facilitate studying the functional roles of teleost T cells during immune responses. Although there is still a long way to go, major advances have occurred in recent years for investigating T cell responses, thus phenotypic and functional characterization is on the near horizon.

  15. A two-dimensional (azimuthal-axial) particle-in-cell model of a Hall thruster

    NASA Astrophysics Data System (ADS)

    Coche, P.; Garrigues, L.

    2014-02-01

    We have developed a two-dimensional Particle-In-Cell model in the azimuthal and axial directions of the Hall thruster. A scaling method that consists to work at a lower plasma density to overcome constraints on time-step and grid-spacing is used. Calculations are able to reproduce the breathing mode due to a periodic depletion of neutral atoms without the introduction of a supplementary anomalous mechanism, as in fluid and hybrid models. Results show that during the increase of the discharge current, an electron-cyclotron drift instability (frequency in the range of MHz and wave number on the order of 3000 rad s-1) is formed in the region of the negative gradient of magnetic field. During the current decrease, an axial electric wave propagates from the channel toward the exhaust (whose frequency is on the order of 400 kHz) leading to a broadening of the ion energy distribution function. A discussion about the influence of the scaling method on the calculation results is also proposed.

  16. Recent Advances in Solar Cell Technology

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Bailey, Sheila G.; Piszczor, Michael F., Jr.

    1996-01-01

    The advances in solar cell efficiency, radiation tolerance, and cost over the last decade are reviewed. Potential performance of thin-film solar cells in space are discussed, and the cost and the historical trends in production capability of the photovoltaics industry are considered with respect to the requirements of space power systems. Concentrator cells with conversion efficiency over 30%, and nonconcentrating solar cells with efficiency over 25% are now available, and advanced radiation-tolerant cells and lightweight, thin-film arrays are both being developed. Nonsolar applications of solar cells, including thermophotovoltaics, alpha- and betavoltaics, and laser power receivers, are also discussed.

  17. 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.

  18. NASA's Hall Thruster Program

    NASA Technical Reports Server (NTRS)

    Jankovsky, Robert S.; Jacobson, David T.; Rawlin, Vincent K.; Mason, Lee S.; Mantenieks, Maris A.; Manzella, David H.; Hofer, Richard R.; Peterson, Peter Y.

    2001-01-01

    NASA's Hall thruster program has base research and focused development efforts in support of the Advanced Space Transportation Program, Space-Based Program, and various other programs. The objective of the base research is to gain an improved understanding of the physical processes and engineering constraints of Hall thrusters to enable development of advanced Hall thruster designs. Specific technical questions that are current priorities of the base effort are: (1) How does thruster life vary with operating point? (2) How can thruster lifetime and wear rate be most efficiently evaluated? (3) What are the practical limitations for discharge voltage as it pertains to high specific impulse operation (high discharge voltage) and high thrust operation (low discharge voltage)? (4) What are the practical limits for extending Hall thrusters to very high input powers? and (5) What can be done during thruster design to reduce cost and integration concerns? The objective of the focused development effort is to develop a 50 kW-class Hall propulsion system, with a milestone of a 50 kW engineering model thruster/system by the end of program year 2006. Specific program wear 2001 efforts, along with the corporate and academic participation, are described.

  19. A New Cell-Centered Implicit Numerical Scheme for Ions in the 2-D Axisymmetric Code Hall2de

    NASA Technical Reports Server (NTRS)

    Lopez Ortega, Alejandro; Mikellides, Ioannis G.

    2014-01-01

    We present a new algorithm in the Hall2De code to simulate the ion hydrodynamics in the acceleration channel and near plume regions of Hall-effect thrusters. This implementation constitutes an upgrade of the capabilities built in the Hall2De code. The equations of mass conservation and momentum for unmagnetized ions are solved using a conservative, finite-volume, cell-centered scheme on a magnetic-field-aligned grid. Major computational savings are achieved by making use of an implicit predictor/multi-corrector algorithm for time evolution. Inaccuracies in the prediction of the motion of low-energy ions in the near plume in hydrodynamics approaches are addressed by implementing a multi-fluid algorithm that tracks ions of different energies separately. A wide range of comparisons with measurements are performed to validate the new ion algorithms. Several numerical experiments with the location and value of the anomalous collision frequency are also presented. Differences in the plasma properties in the near-plume between the single fluid and multi-fluid approaches are discussed. We complete our validation by comparing predicted erosion rates at the channel walls of the thruster with measurements. Erosion rates predicted by the plasma properties obtained from simulations replicate accurately measured rates of erosion within the uncertainty range of the sputtering models employed.

  20. Advances in stem cell therapy.

    PubMed

    Pérez López, Silvia; Otero Hernández, Jesús

    2012-01-01

    Since the beginning of stem cell biology, considerable effort has been focused in the translation of scientific insights into new therapies. Cell-based assays represent a new strategy for organ and tissue repair in several pathologies. Moreover, alternative treatment strategies are urgently needed due to donor organ shortage that costs many lives every year and results in lifelong immunosuppression. At the moment, only the use of hematopoietic stem cells is considered as the standard for the treatment of malignant and genetic bone marrow disorders, being all other stem cell applications highly experimental. The present chapter tries to summarize some ongoing approaches of stem cell regenerative medicine and also introduces recent findings from published studies and trials conducted in various tissues such as skeletal muscle, liver and lung.

  1. Advances in Perovskite Solar Cells

    PubMed Central

    Zuo, Chuantian; Bolink, Henk J.; Han, Hongwei; Huang, Jinsong

    2016-01-01

    Organolead halide perovskite materials possess a combination of remarkable optoelectronic properties, such as steep optical absorption edge and high absorption coefficients, long charge carrier diffusion lengths and lifetimes. Taken together with the ability for low temperature preparation, also from solution, perovskite‐based devices, especially photovoltaic (PV) cells have been studied intensively, with remarkable progress in performance, over the past few years. The combination of high efficiency, low cost and additional (non‐PV) applications provides great potential for commercialization. Performance and applications of perovskite solar cells often correlate with their device structures. Many innovative device structures were developed, aiming at large‐scale fabrication, reducing fabrication cost, enhancing the power conversion efficiency and thus broadening potential future applications. This review summarizes typical structures of perovskite solar cells and comments on novel device structures. The applications of perovskite solar cells are discussed. PMID:27812475

  2. Prostate Cancer Stem Cells: Research Advances

    PubMed Central

    Jaworska, Dagmara; Król, Wojciech; Szliszka, Ewelina

    2015-01-01

    Cancer stem cells have been defined as cells within a tumor that possesses the capacity to self-renew and to cause the heterogeneous lineages of cancer cells that comprise the tumor. Experimental evidence showed that these highly tumorigenic cells might be responsible for initiation and progression of cancer into invasive and metastatic disease. Eradicating prostate cancer stem cells, the root of the problem, has been considered as a promising target in prostate cancer treatment to improve the prognosis for patients with advanced stages of the disease. PMID:26593898

  3. Development of advanced fuel cell system

    NASA Technical Reports Server (NTRS)

    Grevstad, P. E.

    1972-01-01

    Weight, life and performance characteristics optimization of hydrogen-oxygen fuel cell power systems were considered. A promising gold alloy cathode catalyst was identified and tested in a cell for 5,000 hours. The compatibility characteristics of candidate polymer structural materials were measured after exposure to electrolyte and water vapor for 8,000 hours. Lightweight cell designs were prepared and fabrication techniques to produce them were developed. Testing demonstrated that predicted performance was achieved. Lightweight components for passive product water removal and evaporative cooling of cells were demonstrated. Systems studies identified fuel cell powerplant concepts for meeting the requirements of advanced spacecraft.

  4. Prostate Cancer Stem Cells: Research Advances.

    PubMed

    Jaworska, Dagmara; Król, Wojciech; Szliszka, Ewelina

    2015-01-01

    Cancer stem cells have been defined as cells within a tumor that possesses the capacity to self-renew and to cause the heterogeneous lineages of cancer cells that comprise the tumor. Experimental evidence showed that these highly tumorigenic cells might be responsible for initiation and progression of cancer into invasive and metastatic disease. Eradicating prostate cancer stem cells, the root of the problem, has been considered as a promising target in prostate cancer treatment to improve the prognosis for patients with advanced stages of the disease.

  5. Advanced direct methanol fuel cells. Final report

    SciTech Connect

    Hamdan, Monjid; Kosek, John A.

    1999-11-01

    The goal of the program was an advanced proton-exchange membrane (PEM) for use as the electrolyte in a liquid feed direct methanol fuel cell which provides reduced methanol crossover while simultaneously providing high conductivity and low membrane water content. The approach was to use a membrane containing precross-linked fluorinated base polymer films and subsequently to graft the base film with selected materials. Over 80 different membranes were prepared. The rate of methanol crossover through the advanced membranes was reduced 90%. A 5-cell stack provided stable performance over a 100-hour life test. Preliminary cost estimates predicted a manufacturing cost at $4 to $9 per kW.

  6. Advanced Catalysts for Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R.; Whitacre, Jay; Valdez, T. I.

    2006-01-01

    This viewgraph presentation reviews the development of catalyst for Fuel Cells. The objectives of the project are to reduce the cost of stack components and reduce the amount of precious metal used in fuel cell construction. A rapid combinatorial screening technique based on multi-electrode thin film array has been developed and validated for identifying catalysts for oxygen reduction; focus shifted from methanol oxidation in FY05 to oxygen reduction in FY06. Multi-electrode arrays of thin film catalysts of Pt-Ni and Pt-Ni-Zr have been deposited. Pt-Ni and have been characterized electrochemically and structurally. Pt-Ni-Zr and Pt-Ni films show higher current density and onset potential compared to Pt. Electrocatalytic activity and onset potential are found to be strong function of the lattice constant. Thin film Pt(59)Ni(39)Zr(2) can provide 10 times the current density of thin film Pt. Thin film Pt(59)Ni(39)Zr(2) also shows 65mV higher onset potential than Pt.

  7. Advanced Cell Development and Degradation Studies

    SciTech Connect

    J. E. O'Brien; C. M. Stoots; J. S. Herring; R. C. O'Brien; K. G. Condie; M. Sohal; G. K. Housley; J. J. Hartvigsen; D. Larsen; G. Tao; B. Yildiz; V. Sharma; P. Singh; N. Petigny; T. L. Cable

    2010-09-01

    The Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells for large-scale hydrogen production from steam over a temperature range of 800 to 900ºC. From 2003 – 2009, this work was sponsored by the DOE Nuclear Hydrogen Initiative (NHI). Starting in 2010, the HTE research program has been sponsored by the Next Generation Nuclear Plant (NGNP) program. HTSE research priorities in FY10 are centered on understanding and reducing cell and stack performance degradation to an acceptable level to advance the technology readiness level of HTSE and to justify further large-scale demonstration activities. This report provides a summary of our FY10 experimental program, which has been focused on advanced cell and stack development and degradation studies. Advanced cell and stack development activities are under way at five technology partners: MSRI, Versa Power, Ceramatec, NASA Glenn, and St. Gobain. Performance evaluation of the advanced technology cells and stacks has been performed by the technology partners, by MIT and the University of Connecticut and at the INL HTE Laboratory. Summaries of these development activities and test results are presented.

  8. Comparative values of advanced space solar cells

    NASA Technical Reports Server (NTRS)

    Slifer, L. W., Jr.

    1982-01-01

    A methodology for deriving a first order dollar value estimate for advanced solar cells which consists of defining scenarios for solar array production and launch to orbit and the associated costs for typical spacecraft, determining that portion affected by cell design and performance and determining the attributable cost differences is presented. Break even values are calculated for a variety of cells; confirming that efficiency and related effects of radiation resistance and temperature coefficient are major factors; array tare mass, packaging and packing factor are important; but cell mass is of lesser significance. Associated dollar values provide a means of comparison.

  9. Advances in ambient temperature secondary lithium cells

    NASA Technical Reports Server (NTRS)

    Subbarao, S.; Shen, D. H.; Deligiannis, F.; Huang, C-K.; Halpert, G.

    1989-01-01

    The goal is to develop secondary lithium cells with a 100 Wh/kg specific energy capable of 1000 cycles at 50 percent DOD. The approach towards meeting this goal initially focused on several basic issues related to the cell chemistry, selection of cathode materials and electrolytes and component development. The performance potential of Li-TiS2, Li-MoS3, Li-V6O13 and Li-NbSe3 electrochemical systems was examined. Among these four, the Li-TiS2 system was found to be the most promising system in terms of achievable specific energy and cycle life. Major advancements to date in the development of Li-TiS2 cells are in the areas of cathode processing technology, mixed solvent electrolytes, and cell assembly. A summary is given of these advances.

  10. Hall viscosity

    NASA Astrophysics Data System (ADS)

    Read, Nicholas

    2015-03-01

    Viscosity is a transport coefficient relating to transport of momentum, and usually thought of as the analog of friction that occurs in fluids and solids. More formally, it is the response of the stress to the gradients of the fluid velocity field, or to the rate of change of strain (derivatives of displacement from a reference state). In general, viscosity is described by a fourth-rank tensor. Invoking rotation invariance, it reduces to familiar shear and bulk viscosity parts, which describe dissipation, but it can also contain an antisymmetric part, analogous to the Hall conductivity part of the conductivity tensor. In two dimensions this part is a single number, the Hall viscosity. Symmetry of the system under time reversal (or, in two dimensions, reflections) forces it to vanish. In quantum fluids with a gap in the bulk energy spectrum and which lack both time reversal and reflection symmetries the Hall viscosity can be nonzero even at zero temperature. For integer quantum Hall states, it was first calculated by Avron, Seiler, and Zograf, using a Berry curvature approach, analogous to the Chern number for Hall conductivity. In 2008 this was extended by the present author to fractional quantum Hall states and to BCS states in two dimensions. I found that the general result is given by a simple formula ns / 2 , where n is the particle number density, and s is the ``orbital spin'' per particle. The spin s is also related to the shift S, which enters the relation between particle number and magnetic flux needed to put the ground state on a surface of non-trivial topology with introducing defect excitations, by S = 2 s ; the connection was made by Wen and Zee. The values of s and S are rational numbers, and are robust--unchanged under perturbations that do not cause the bulk energy gap to collapse--provided rotation as well as translation symmetry are maintained. Hall viscosity can be measured in principle, though a simple way to do so is lacking. It enters various

  11. Advances in Reprogramming Somatic Cells to Induced Pluripotent Stem Cells

    PubMed Central

    Patel, Minal; Yang, Shuying

    2010-01-01

    Traditionally, nuclear reprogramming of cells has been performed by transferring somatic cell nuclei into oocytes, by combining somatic and pluripotent cells together through cell fusion and through genetic integration of factors through somatic cell chromatin. All of these techniques changes gene expression which further leads to a change in cell fate. Here we discuss recent advances in generating induced pluripotent stem cells, different reprogramming methods and clinical applications of iPS cells. Viral vectors have been used to transfer transcription factors (Oct4, Sox2, c-myc, Klf4, and nanog) to induce reprogramming of mouse fibroblasts, neural stem cells, neural progenitor cells, keratinocytes, B lymphocytes and meningeal membrane cells towards pluripotency. Human fibroblasts, neural cells, blood and keratinocytes have also been reprogrammed towards pluripotency. In this review we have discussed the use of viral vectors for reprogramming both animal and human stem cells. Currently, many studies are also involved in finding alternatives to using viral vectors carrying transcription factors for reprogramming cells. These include using plasmid transfection, piggyback transposon system and piggyback transposon system combined with a non viral vector system. Applications of these techniques have been discussed in detail including its advantages and disadvantages. Finally, current clinical applications of induced pluripotent stem cells and its limitations have also been reviewed. Thus, this review is a summary of current research advances in reprogramming cells into induced pluripotent stem cells. PMID:20336395

  12. Evaluation of High-Power Solar Electric Propulsion using Advanced Ion, Hall, MPD, and PIT Thrusters for Lunar and Mars Cargo Missions

    NASA Technical Reports Server (NTRS)

    Frisbee, Robert H.

    2006-01-01

    This paper presents the results of mission analyses that expose the advantages and disadvantages of high-power (MWe-class) Solar Electric Propulsion (SEP) for Lunar and Mars Cargo missions that would support human exploration of the Moon and Mars. In these analyses, we consider SEP systems using advanced Ion thrusters (the Xenon [Xe] propellant Herakles), Hall thrusters (the Bismuth [Bi] propellant Very High Isp Thruster with Anode Layer [VHITAL], magnetoplasmadynamic (MPD) thrusters (the Lithium [Li] propellant Advanced Lithium-Fed, Applied-field Lorentz Force Accelerator (ALFA2), and pulsed inductive thruster (PIT) (the Ammonia [NH3] propellant Nuclear-PIT [NuPIT]). The analyses include comparison of the advanced-technology propulsion systems (VHITAL, ALFA2, and NuPIT) relative to state-of-theart Ion (Herakles) propulsion systems and quantify the unique benefits of the various technology options such as high power-per-thruster (and/or high power-per-thruster packaging volume), high specific impulse (Isp), high-efficiency, and tankage mass (e.g., low tankage mass due to the high density of bismuth propellant). This work is based on similar analyses for Nuclear Electric Propulsion (NEP) systems.

  13. Advanced Solar Cells for Satellite Power Systems

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.; Weinberg, Irving

    1994-01-01

    The multiple natures of today's space missions with regard to operational lifetime, orbital environment, cost and size of spacecraft, to name just a few, present such a broad range of performance requirements to be met by the solar array that no single design can suffice to meet them all. The result is a demand for development of specialized solar cell types that help to optimize overall satellite performance within a specified cost range for any given space mission. Historically, space solar array performance has been optimized for a given mission by tailoring the features of silicon solar cells to account for the orbital environment and average operating conditions expected during the mission. It has become necessary to turn to entirely new photovoltaic materials and device designs to meet the requirements of future missions, both in the near and far term. This paper will outline some of the mission drivers and resulting performance requirements that must be met by advanced solar cells, and provide an overview of some of the advanced cell technologies under development to meet them. The discussion will include high efficiency, radiation hard single junction cells; monolithic and mechanically stacked multiple bandgap cells; and thin film cells.

  14. Shockley-Read-Hall recombination in pre-filled and photo-filled intermediate band solar cells

    SciTech Connect

    Mayani, Maryam Gholami; Reenaas, Turid Worren

    2014-08-18

    In this work, we study how Shockley-Read-Hall (SRH) recombination via energy levels in the bandgap, caused by defects or impurities, affects the performance of both photo-filled and pre-filled intermediate band solar cells (IBSCs). For a pre-filled cell, the IB is half-filled in equilibrium, while it is empty for the photo-filled cell in equilibrium. The energy level, density, and capture cross-sections of the defects/impurities are varied systematically. We find that the photo-filled cells are, in general, less efficient than pre-filled cells, except when the defect level is between the conduction band and the IB. In that case, for a range of light intensities, the photo-filled cell performs better than the pre-filled. When the defect level is at the same energy as the IB, the efficiency is above 82% of the defect-free case, when less than 50% of the states at the IB lead to SRH recombination. This shows that even if SRH recombination via the IB takes place, high efficiencies can be achieved. We also show that band gap optimization can be used to reduce the SRH recombination.

  15. Advanced space power PEM fuel cell systems

    NASA Technical Reports Server (NTRS)

    Vanderborgh, N. E.; Hedstrom, J.; Huff, J. R.

    1989-01-01

    A model showing mass and heat transfer in proton exchange membrane (PEM) single cells is presented. For space applications, stack operation requiring combined water and thermal management is needed. Advanced hardware designs able to combine these two techniques are available. Test results are shown for membrane materials which can operate with sufficiently fast diffusive water transport to sustain current densities of 300 ma per square centimeter. Higher power density levels are predicted to require active water removal.

  16. Advances in ambient temperature secondary lithium cells

    NASA Technical Reports Server (NTRS)

    Subbarao, S.; Shen, D. H.; Deligiannis, F.; Huang, C.-K.; Halpert, G.

    1990-01-01

    The goal of the NASA/OAST sponsored program on the development of ambient-temperature secondary lithium cells for future space applications is to develop cells with a 100 W h/kg specific energy and capable of 1000 cycles at 50-percent depth of discharge. This paper examines the performance potentials of Li-TiS2, Li-MoS3, Li-V6O13, and Li-NbSe3 electrochemical systems at ambient temperature, together with cycle life and safety characteristics. Of these four, the Li-TiS2 system was found to be the most promising in terms of achievable specific energy and cycle life. Major advances made on the development of secondary lithium cells, which are in the areas of cathode processing technology, mixed solvent electrolytes, and cell assembly, are summarized.

  17. Technology Advancement for Integrative Stem Cell Analyses

    PubMed Central

    Jeong, Yoon

    2014-01-01

    Scientists have endeavored to use stem cells for a variety of applications ranging from basic science research to translational medicine. Population-based characterization of such stem cells, while providing an important foundation to further development, often disregard the heterogeneity inherent among individual constituents within a given population. The population-based analysis and characterization of stem cells and the problems associated with such a blanket approach only underscore the need for the development of new analytical technology. In this article, we review current stem cell analytical technologies, along with the advantages and disadvantages of each, followed by applications of these technologies in the field of stem cells. Furthermore, while recent advances in micro/nano technology have led to a growth in the stem cell analytical field, underlying architectural concepts allow only for a vertical analytical approach, in which different desirable parameters are obtained from multiple individual experiments and there are many technical challenges that limit vertically integrated analytical tools. Therefore, we propose—by introducing a concept of vertical and horizontal approach—that there is the need of adequate methods to the integration of information, such that multiple descriptive parameters from a stem cell can be obtained from a single experiment. PMID:24874188

  18. Technology advancement for integrative stem cell analyses.

    PubMed

    Jeong, Yoon; Choi, Jonghoon; Lee, Kwan Hyi

    2014-12-01

    Scientists have endeavored to use stem cells for a variety of applications ranging from basic science research to translational medicine. Population-based characterization of such stem cells, while providing an important foundation to further development, often disregard the heterogeneity inherent among individual constituents within a given population. The population-based analysis and characterization of stem cells and the problems associated with such a blanket approach only underscore the need for the development of new analytical technology. In this article, we review current stem cell analytical technologies, along with the advantages and disadvantages of each, followed by applications of these technologies in the field of stem cells. Furthermore, while recent advances in micro/nano technology have led to a growth in the stem cell analytical field, underlying architectural concepts allow only for a vertical analytical approach, in which different desirable parameters are obtained from multiple individual experiments and there are many technical challenges that limit vertically integrated analytical tools. Therefore, we propose--by introducing a concept of vertical and horizontal approach--that there is the need of adequate methods to the integration of information, such that multiple descriptive parameters from a stem cell can be obtained from a single experiment.

  19. Advanced Treatment for Basal Cell Carcinomas

    PubMed Central

    Atwood, Scott X.; Whitson, Ramon J.; Oro, Anthony E.

    2014-01-01

    Basal cell carcinomas (BCCs) are very common epithelial cancers that depend on the Hedgehog pathway for tumor growth. Traditional therapies such as surgical excision are effective for most patients with sporadic BCC; however, better treatment options are needed for cosmetically sensitive or advanced and metastatic BCC. The first approved Hedgehog antagonist targeting the membrane receptor Smoothened, vismodegib, shows remarkable effectiveness on both syndromic and nonsyndromic BCCs. However, drug-resistant tumors frequently develop, illustrating the need for the development of next-generation Hedgehog antagonists targeting pathway components downstream from Smoothened. In this article, we will summarize available BCC treatment options and discuss the development of next-generation antagonists. PMID:24985127

  20. Not your grandfather's concert hall

    NASA Astrophysics Data System (ADS)

    Cooper, Russell; Malenka, Richard; Griffith, Charles; Friedlander, Steven

    2001-05-01

    The opening of Judy and Arthur Zankel Hall on 12 September 2003, restores Andrew Carnegie's original 1891 concept of having three outstanding auditoriums of different sizes under one roof, and creates a 21st-century venue for music performance and education. With concerts ranging from early music to avant-garde multimedia productions, from jazz to world music, and from solo recitals to chamber music, Zankel Hall expands the breadth and depth of Carnegie Hall's offerings. It allows for the integration of programming across three halls with minifestivals tailored both to the size and strengths of each hall and to the artists and music to be performed. The new flexible space also provides Carnegie Hall with an education center equipped with advanced communications technology. This paper discusses the unique program planned for this facility and how the architects, theatre consultants, and acousticians developed a design that fulfilled the client's expectations and coordinated the construction of the facility under the floor of the main Isaac Stern Auditorium without having to cancel a single performance.

  1. Advances in Human B Cell Phenotypic Profiling

    PubMed Central

    Kaminski, Denise A.; Wei, Chungwen; Qian, Yu; Rosenberg, Alexander F.; Sanz, Ignacio

    2012-01-01

    To advance our understanding and treatment of disease, research immunologists have been called-upon to place more centralized emphasis on impactful human studies. Such endeavors will inevitably require large-scale study execution and data management regulation (“Big Biology”), necessitating standardized and reliable metrics of immune status and function. A well-known example setting this large-scale effort in-motion is identifying correlations between eventual disease outcome and T lymphocyte phenotype in large HIV-patient cohorts using multiparameter flow cytometry. However, infection, immunodeficiency, and autoimmunity are also characterized by correlative and functional contributions of B lymphocytes, which to-date have received much less attention in the human Big Biology enterprise. Here, we review progress in human B cell phenotyping, analysis, and bioinformatics tools that constitute valuable resources for the B cell research community to effectively join in this effort. PMID:23087687

  2. Advances in retinal ganglion cell imaging

    PubMed Central

    Balendra, S I; Normando, E M; Bloom, P A; Cordeiro, M F

    2015-01-01

    Glaucoma is one of the leading causes of blindness worldwide and will affect 79.6 million people worldwide by 2020. It is caused by the progressive loss of retinal ganglion cells (RGCs), predominantly via apoptosis, within the retinal nerve fibre layer and the corresponding loss of axons of the optic nerve head. One of its most devastating features is its late diagnosis and the resulting irreversible visual loss that is often predictable. Current diagnostic tools require significant RGC or functional visual field loss before the threshold for detection of glaucoma may be reached. To propel the efficacy of therapeutics in glaucoma, an earlier diagnostic tool is required. Recent advances in retinal imaging, including optical coherence tomography, confocal scanning laser ophthalmoscopy, and adaptive optics, have propelled both glaucoma research and clinical diagnostics and therapeutics. However, an ideal imaging technique to diagnose and monitor glaucoma would image RGCs non-invasively with high specificity and sensitivity in vivo. It may confirm the presence of healthy RGCs, such as in transgenic models or retrograde labelling, or detect subtle changes in the number of unhealthy or apoptotic RGCs, such as detection of apoptosing retinal cells (DARC). Although many of these advances have not yet been introduced to the clinical arena, their successes in animal studies are enthralling. This review will illustrate the challenges of imaging RGCs, the main retinal imaging modalities, the in vivo techniques to augment these as specific RGC-imaging tools and their potential for translation to the glaucoma clinic. PMID:26293138

  3. Advances in Stem Cell Therapy for Leukemia.

    PubMed

    Tian, Hong; Qu, Qi; Liu, Liming; Wu, Depei

    2016-01-01

    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the most effective post remission treatment for leukemia, resulting in lower relapse rates than alternative therapies. However, it is limited by the lack of suitable human leukocyte antigen (HLA) matched donors and high rates of transplant-related morbidity and mortality. Cord blood transplantation (CBT) and haploidentical SCT (haplo-SCT) expand the potential donor pool but are also associated with major complications. Co-infusion of third-party donor stem cells with a CBT/haplo-SCT, which is called "dual transplantation," has been reported to improve the outcome of HSCT by accelerating hematopoietic reconstitution and reducing the incidence of graft-versus-host disease (GVHD). In addition, infusion of HLA-mismatched donor granulocyte colony-stimulating factor-mobilized donor peripheral blood stem cells after chemotherapy, the so called "microtransplantation", has been shown to promote the graft-versus-leukemia effect and hasten hematopoietic recovery without amplifying GVHD. Herein, we review recent advances in stem cell therapy for leukemia with a specific focus on dual transplantation and microtransplantation.

  4. Predictive markers in advanced renal cell carcinoma.

    PubMed

    Michaelson, M Dror; Stadler, Walter M

    2013-08-01

    Predictive markers of response to therapy are increasingly important in advanced renal cell carcinoma (RCC) due to the proliferation of treatment options in recent years. Different types of potential predictive markers may include clinical, toxicity-based, serum, tissue, and radiologic biomarkers. Clinical factors are commonly used in overall prognostic models of RCC but have limited utility in predicting response to therapy. Correlation between development of particular toxicities and response to therapy has been noted, such as the correlation between hypertension and response to angiogenesis-targeted therapy. Serum and tissue biomarkers will be covered in detail elsewhere, but factors such as serum lactate dehydrogenase (LDH) and circulating cytokines show promise in this regard. Finally, baseline or early treatment radiology studies may have predictive ability for longer term efficacy, with most studies to date focusing on functional imaging modalities such as positron emission tomography (PET) scans, dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), and DCE ultrasound (US). The ultimate goal of developing predictive biomarkers is to enable rational and personalized treatment strategies for patients with advanced RCC. PMID:23972709

  5. Theory for the anomalous electron transport in Hall effect thrusters. I. Insights from particle-in-cell simulations

    NASA Astrophysics Data System (ADS)

    Lafleur, T.; Baalrud, S. D.; Chabert, P.

    2016-05-01

    Using a 1D particle-in-cell simulation with perpendicular electric, E0, and magnetic, B0, fields, and modelling the azimuthal direction (i.e., the E0 × B0 direction), we study the cross-field electron transport in Hall effect thrusters (HETs). For low plasma densities, the electron transport is found to be well described by classical electron-neutral collision theory, but at sufficiently high densities (representative of typical HETs), a strong instability is observed to significantly enhance the electron mobility, even in the absence of electron-neutral collisions. This instability is associated with correlated high-frequency (of the order of MHz) and short-wavelength (of the order of mm) fluctuations in both the electric field and the plasma density, which are shown to be the cause of the anomalous transport. Saturation of the instability is observed to occur due to a combination of ion-wave trapping in the E0 × B0 direction, and convection in the E0 direction.

  6. Advanced membrane electrode assemblies for fuel cells

    SciTech Connect

    Kim, Yu Seung; Pivovar, Bryan S

    2014-02-25

    A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

  7. Advanced membrane electrode assemblies for fuel cells

    DOEpatents

    Kim, Yu Seung; Pivovar, Bryan S.

    2012-07-24

    A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

  8. Quantum hall ferromagnets

    NASA Astrophysics Data System (ADS)

    Kumar, Akshay

    We study several quantum phases that are related to the quantum Hall effect. Our initial focus is on a pair of quantum Hall ferromagnets where the quantum Hall ordering occurs simultaneously with a spontaneous breaking of an internal symmetry associated with a semiconductor valley index. In our first example ---AlAs heterostructures--- we study domain wall structure, role of random-field disorder and dipole moment physics. Then in the second example ---Si(111)--- we show that symmetry breaking near several integer filling fractions involves a combination of selection by thermal fluctuations known as "order by disorder" and a selection by the energetics of Skyrme lattices induced by moving away from the commensurate fillings, a mechanism we term "order by doping". We also study ground state of such systems near filling factor one in the absence of valley Zeeman energy. We show that even though the lowest energy charged excitations are charge one skyrmions, the lowest energy skyrmion lattice has charge > 1 per unit cell. We then broaden our discussion to include lattice systems having multiple Chern number bands. We find analogs of quantum Hall ferromagnets in the menagerie of fractional Chern insulator phases. Unlike in the AlAs system, here the domain walls come naturally with gapped electronic excitations. We close with a result involving only topology: we show that ABC stacked multilayer graphene placed on boron nitride substrate has flat bands with non-zero local Berry curvature but zero Chern number. This allows access to an interaction dominated system with a non-trivial quantum distance metric but without the extra complication of a non-zero Chern number.

  9. Trapping behavior of Shockley-Read-Hall recombination centers in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Gogolin, R.; Harder, N. P.

    2013-08-01

    We investigate the correlation between increased apparent carrier lifetime in photoconductance-based lifetime measurements and actually reduced recombination lifetime as measured by photoluminescence measurements. These findings are further reconfirmed by I-V curve measurements of solar cells. In particular, we show experimental results for lifetime samples and solar cells with and without hydrogen passivation. In the samples and solar cells without hydrogen passivation, we find both a stronger trapping behavior and a lower recombination lifetime. Our model provides a consistent description of the observation of both, the increased apparent lifetime from carrier trapping and the decreasing recombination lifetime. In our model, both are caused by a single physical mechanism; i.e., by Recombination-Active-Trap (RAT) states. Upon fitting the experimental lifetime data, we find that the RAT-defect parameters for the hydrogen-passivated and non-hydrogen-passivated lifetime samples and solar cells are identical except for the defect concentration: hydrogen-passivation reduced the defect density by 50% in both, the lifetime samples and solar cells. We conclude that trapping should be considered as an indication for hidden, yet potentially strongly increased, low injection recombination activity.

  10. Cathode for a hall-heroult type electrolytic cell for producing aluminum

    DOEpatents

    Brown, Craig W.

    2004-04-13

    A method of producing aluminum from alumina in an electrolytic cell including using a cathode comprised of a base material having low electrical conductivity and wettable with molten aluminum to form a reaction layer having a high electrical conductivity on said base layer and a cathode bar extending from said reaction layer through said base material to conduct electrical current from said reaction layer.

  11. Development of advanced fuel cell system, phase 2

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    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. Development and characterization of a very stable gold alloy catalyst was continued from Phase I of the program. A polymer material for fabrication of cell structural components was identified and its long term compatibility with the fuel cell environment was demonstrated in cell tests. Full scale partial cell stacks, with advanced design closed cycle evaporative coolers, were tested. The characteristics demonstrated in these tests verified the feasibility of developing the engineering model system concept into an advanced lightweight long life powerplant.

  12. Microscale microbial fuel cells: Advances and challenges.

    PubMed

    Choi, Seokheun

    2015-07-15

    The next generation of sustainable energy could come from microorganisms; evidence that it can be seen with the given rise of Electromicrobiology, the study of microorganisms' electrical properties. Many recent advances in electromicrobiology stem from studying microbial fuel cells (MFCs), which are gaining acceptance as a future alternative "green" energy technology and energy-efficient wastewater treatment method. MFCs are powered by living microorganisms with clean and sustainable features; they efficiently catalyse the degradation of a broad range of organic substrates under natural conditions. There is also increasing interest in photosynthetic MFCs designed to harness Earth's most abundant and promising energy source (solar irradiation). Despite their vast potential and promise, however, MFCs and photosynthetic MFCs have not yet successfully translated into commercial applications because they demonstrate persistent performance limitations and bottlenecks associated with scaling up. Instead, microscale MFCs have received increasing attention as a unique platform for various applications such as powering small portable electronic elements in remote locations, performing fundamental studies of microorganisms, screening bacterial strains, and toxicity detection in water. Furthermore, the stacking of miniaturized MFCs has been demonstrated to offer larger power densities than a single macroscale MFC in terms of scaling up. In this overview, we discuss recent achievements in microscale MFCs as well as their potential applications. Further scientific and technological challenges are also reviewed.

  13. The quantum Hall effects: Philosophical approach

    NASA Astrophysics Data System (ADS)

    Lederer, P.

    2015-05-01

    The Quantum Hall Effects offer a rich variety of theoretical and experimental advances. They provide interesting insights on such topics as gauge invariance, strong interactions in Condensed Matter physics, emergence of new paradigms. This paper focuses on some related philosophical questions. Various brands of positivism or agnosticism are confronted with the physics of the Quantum Hall Effects. Hacking's views on Scientific Realism, Chalmers' on Non-Figurative Realism are discussed. It is argued that the difficulties with those versions of realism may be resolved within a dialectical materialist approach. The latter is argued to provide a rational approach to the phenomena, theory and ontology of the Quantum Hall Effects.

  14. Advances in measuring single-cell pharmacology in vivo.

    PubMed

    Vinegoni, Claudio; Dubach, J Matthew; Thurber, Greg M; Miller, Miles A; Mazitschek, Ralph; Weissleder, Ralph

    2015-09-01

    Measuring key pharmacokinetic and pharmacodynamic parameters in vivo at the single cell level is likely to enhance drug discovery and development. In this review, we summarize recent advances in this field and highlight current and future capabilities. PMID:26024776

  15. Process Technology and Advanced Concepts: Organic Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2011-06-01

    Capabilities fact sheet for the National Center for Photovoltaics: Process Technology and Advanced Concepts: Organic Solar Cell that includes scope, core competencies and capabilities, and contact/web information.

  16. Stem and progenitor cells: advancing bone tissue engineering.

    PubMed

    Tevlin, R; Walmsley, G G; Marecic, O; Hu, Michael S; Wan, D C; Longaker, M T

    2016-04-01

    Unlike many other postnatal tissues, bone can regenerate and repair itself; nevertheless, this capacity can be overcome. Traditionally, surgical reconstructive strategies have implemented autologous, allogeneic, and prosthetic materials. Autologous bone--the best option--is limited in supply and also mandates an additional surgical procedure. In regenerative tissue engineering, there are myriad issues to consider in the creation of a functional, implantable replacement tissue. Importantly, there must exist an easily accessible, abundant cell source with the capacity to express the phenotype of the desired tissue, and a biocompatible scaffold to deliver the cells to the damaged region. A literature review was performed using PubMed; peer-reviewed publications were screened for relevance in order to identify key advances in stem and progenitor cell contribution to the field of bone tissue engineering. In this review, we briefly introduce various adult stem cells implemented in bone tissue engineering such as mesenchymal stem cells (including bone marrow- and adipose-derived stem cells), endothelial progenitor cells, and induced pluripotent stem cells. We then discuss numerous advances associated with their application and subsequently focus on technological advances in the field, before addressing key regenerative strategies currently used in clinical practice. Stem and progenitor cell implementation in bone tissue engineering strategies have the ability to make a major impact on regenerative medicine and reduce patient morbidity. As the field of regenerative medicine endeavors to harness the body's own cells for treatment, scientific innovation has led to great advances in stem cell-based therapies in the past decade.

  17. Workshop II: Nanotechnology and Advanced Cell Concepts

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Workshop focused on few emerging concepts(beyond tandem cells): 1. Engineering incident sun spectrum and transparency losses a) Nano emitters (dot concentrator); b) Surface plasmonics; c) Up converters; d) Down converter. 2. Intermediate band solar cells a) Efficiency projections (detail energy balance projections); b) Inserting 0,1 and 2D semiconductor structures in solar cells 3. Polymer and hybrid cells a) Nanotubes/dot polymers; b) Exciton dissociation.

  18. Advances in cell culture: anchorage dependence

    PubMed Central

    Merten, Otto-Wilhelm

    2015-01-01

    Anchorage-dependent cells are of great interest for various biotechnological applications. (i) They represent a formidable production means of viruses for vaccination purposes at very large scales (in 1000–6000 l reactors) using microcarriers, and in the last decade many more novel viral vaccines have been developed using this production technology. (ii) With the advent of stem cells and their use/potential use in clinics for cell therapy and regenerative medicine purposes, the development of novel culture devices and technologies for adherent cells has accelerated greatly with a view to the large-scale expansion of these cells. Presently, the really scalable systems—microcarrier/microcarrier-clump cultures using stirred-tank reactors—for the expansion of stem cells are still in their infancy. Only laboratory scale reactors of maximally 2.5 l working volume have been evaluated because thorough knowledge and basic understanding of critical issues with respect to cell expansion while retaining pluripotency and differentiation potential, and the impact of the culture environment on stem cell fate, etc., are still lacking and require further studies. This article gives an overview on critical issues common to all cell culture systems for adherent cells as well as specifics for different types of stem cells in view of small- and large-scale cell expansion and production processes. PMID:25533097

  19. Advanced Fuel Cell System Thermal Management for NASA Exploration Missions

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.

    2009-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA exploration program. An analysis of a state-of-the-art fuel cell cooling systems was done to benchmark the portion of a fuel cell system s mass that is dedicated to thermal management. Additional analysis was done to determine the key performance targets of the advanced passive thermal management technology that would substantially reduce fuel cell system mass.

  20. Neural stem cells-trends and advances.

    PubMed

    English, Denis; Sharma, Neel K; Sharma, Kaushal; Anand, Akshay

    2013-04-01

    For many years, accepted dogma held that brain is a static organ with no possibility of regeneration of cells in injured or diseased human brain. However, recent preclinical reports have shown regenerative potential of neural stem cells using various injury models. This has resulted in renewed hope for those suffering from spinal cord injury and neural damage. As the potential of stem cell therapy gained impact, these claims, in particular, led to widespread enthusiasm that acute and chronic injury of the nervous system would soon be a problem of the past. The devastation caused by injury or diseases of the brain and spinal cord led to wide premature acceptance that "neural stem cells (NSCs)" derived from embryonic, fetal or adult sources would soon be effective in reversing neural and spinal trauma. However, neural therapy with stem cells has not been realized to its fullest extent. Although, discrete population of regenerative stem cells seems to be present in specific areas of human brain, the function of these cells is unclear. However, similar cells in animals seem to play important role in postnatal growth as well as recovery of neural tissue from injury, anoxia, or disease.

  1. Advances in culture and manipulation of human pluripotent stem cells.

    PubMed

    Qian, X; Villa-Diaz, L G; Krebsbach, P H

    2013-11-01

    Recent advances in the understanding of pluripotent stem cell biology and emerging technologies to reprogram somatic cells to a stem cell-like state are helping bring stem cell therapies for a range of human disorders closer to clinical reality. Human pluripotent stem cells (hPSCs) have become a promising resource for regenerative medicine and research into early development because these cells are able to self-renew indefinitely and are capable of differentiation into specialized cell types of all 3 germ layers and trophoectoderm. Human PSCs include embryonic stem cells (hESCs) derived from the inner cell mass of blastocyst-stage embryos and induced pluripotent stem cells (hiPSCs) generated via the reprogramming of somatic cells by the overexpression of key transcription factors. The application of hiPSCs and the finding that somatic cells can be directly reprogrammed into different cell types will likely have a significant impact on regenerative medicine. However, a major limitation for successful therapeutic application of hPSCs and their derivatives is the potential xenogeneic contamination and instability of current culture conditions. This review summarizes recent advances in hPSC culture and methods to induce controlled lineage differentiation through regulation of cell-signaling pathways and manipulation of gene expression as well as new trends in direct reprogramming of somatic cells.

  2. Spin Hall effect devices.

    PubMed

    Jungwirth, Tomas; Wunderlich, Jörg; Olejník, Kamil

    2012-05-01

    The spin Hall effect is a relativistic spin-orbit coupling phenomenon that can be used to electrically generate or detect spin currents in non-magnetic systems. Here we review the experimental results that, since the first experimental observation of the spin Hall effect less than 10 years ago, have established the basic physical understanding of the phenomenon, and the role that several of the spin Hall devices have had in the demonstration of spintronic functionalities and physical phenomena. We have attempted to organize the experiments in a chronological order, while simultaneously dividing the Review into sections on semiconductor or metal spin Hall devices, and on optical or electrical spin Hall experiments. The spin Hall device studies are placed in a broader context of the field of spin injection, manipulation, and detection in non-magnetic conductors.

  3. Personalized nanomedicine advancements for stem cell tracking☆

    PubMed Central

    Janowski, Mirek; Bulte, Jeff W.M.; Walczak, Piotr

    2012-01-01

    Recent technological developments in biomedicine have facilitated the generation of data on the anatomical, physiological and molecular level for individual patients and thus introduces opportunity for therapy to be personalized in an unprecedented fashion. Generation of patient-specific stem cells exemplifies the efforts toward this new approach. Cell-based therapy is a highly promising treatment paradigm; however, due to the lack of consistent and unbiased data about the fate of stem cells in vivo, interpretation of therapeutic remains challenging hampering the progress in this field. The advent of nanotechnology with a wide palette of inorganic and organic nanostructures has expanded the arsenal of methods for tracking transplanted stem cells. The diversity of nanomaterials has revolutionized personalized nanomedicine and enables individualized tailoring of stem cell labeling materials for the specific needs of each patient. The successful implementation of stem cell tracking will likely be a significant driving force that will contribute to the further development of nanotheranostics. The purpose of this review is to emphasize the role of cell tracking using currently available nanoparticles. PMID:22820528

  4. Astronaut Kevin Chilton works with advanced cell reactor

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Kevin P. Chilton, pilot, works with an advanced cell reactor, which incorporated the first ever videomicroscope, on the Space Tissue Loss (STL-B) experiment on the Space Shuttle Endeavour's middeck. This experiment studied cell growth during the STS-59 mission.

  5. Advances in direct oxidation methanol fuel cells

    NASA Technical Reports Server (NTRS)

    Surampudi, S.; Narayanan, S. R.; Vamos, E.; Frank, H.; Halpert, G.; Laconti, Anthony B.; Kosek, J.; Prakash, G. K. Surya; Olah, G. A.

    1993-01-01

    Fuel cells that can operate directly on fuels such as methanol are attractive for low to medium power applications in view of their low weight and volume relative to other power sources. A liquid feed direct methanol fuel cell has been developed based on a proton exchange membrane electrolyte and Pt/Ru and Pt catalyzed fuel and air/O2 electrodes, respectively. The cell has been shown to deliver significant power outputs at temperatures of 60 to 90 C. The cell voltage is near 0.5 V at 300 mA/cm(exp 2) current density and an operating temperature of 90 C. A deterrent to performance appears to be methanol crossover through the membrane to the oxygen electrode. Further improvements in performance appear possible by minimizing the methanol crossover rate.

  6. Quantum spin Hall effect.

    PubMed

    Bernevig, B Andrei; Zhang, Shou-Cheng

    2006-03-17

    The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. The existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic spin Hall conductance is quantized in units of 2(e/4pi). The degenerate quantum Landau levels are created by the spin-orbit coupling in conventional semiconductors in the presence of a strain gradient. This new state of matter has many profound correlated properties described by a topological field theory.

  7. Quantum Spin Hall Effect

    SciTech Connect

    Bernevig, B.Andrei; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-01-15

    The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. Existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic spin Hall conductance is quantized in units of 2 e/4{pi}. The degenerate quantum Landau levels are created by the spin-orbit coupling in conventional semiconductors in the presence of a strain gradient. This new state of matter has many profound correlated properties described by a topological field theory.

  8. Advanced technology lightweight fuel cell program

    NASA Technical Reports Server (NTRS)

    Martin, R. E.

    1981-01-01

    The potential of the alkaline electrolyte fuel cell as the power source in a multi hundred kilowatt orbital energy storage system was studied. The total system weight of an electrolysis cell energy storage system was determined. The tests demonstrated: (1) the performance stability of a platinum on carbon anode catalyst configuration after 5000 hours of testing has no loss in performance; (2) capability of the alkaline fuel cell to operate to a cyclical load profile; (3) suitability of a lightweight graphite electrolyte reservoir plate for use in the alkaline fuel cell; (4) long life potential of a hybrid polysulfone cell edge frame construction; and (5) long term stability of a fiber reinforced potassium titanate matrix structure. The power section tested operates with passive water removal eliminating the requirement for a dynamic hydrogen pump water separator thereby allowing a powerplant design with reduced weight, lower parasite power, and a potential for high reliability and extended endurance. It is concluded that two perovskites are unsuitable for use as a catalyst or as a catalyst support at the cathode of an alkaline fuel cell.

  9. Advanced fuel cell concepts for future NASA missions

    NASA Technical Reports Server (NTRS)

    Stedman, J. K.

    1987-01-01

    Studies of primary fuel cells for advanced all electric shuttle type vehicles show an all fuel cell power system with peak power capability of 100's of kW to be potentially lighter and have lower life cycle costs than a hybrid system using advanced H2O2 APU's for peak power and fuel cells for low power on orbit. Fuel cell specific weights of 1 to 3 lb/kW, a factor of 10 improvement over the orbiter power plant, are projected for the early 1990's. For satellite applications, a study to identify high performance regenerative hydrogen oxygen fuel cell concepts for geosynchronous orbit was completed. Emphasis was placed on concepts with the potential for high energy density (Wh/lb) and passive means for water and heat management to maximize system reliability. Both alkaline electrolyte and polymer membrane fuel cells were considered.

  10. Recent Advances in Microfluidic Cell Separations

    PubMed Central

    Gao, Yan; Li, Wenjie; Pappas, Dimitri

    2013-01-01

    The isolation and sorting of cells has become an increasingly important step in chemical and biological analyses. As a unit operation in more complex analyses, isolating a phenotypically pure cell population from a heterogeneous sample presents unique challenges. Microfluidic systems are ideal platforms for performing cell separations, enabling integration with other techniques and enhancing traditional separation modalities. In recent years there have been several techniques that use surface antigen affinity, physical interactions, or a combination of the two to achieve high separation purity and efficiency. This review discusses methods including magnetophoretic, acoustophoretic, sedimentation, electric, and hydrodynamic methods for physical separations. We also discuss affinity methods, including magnetic sorting, flow sorting, and affinity capture. PMID:23778244

  11. Fuel cell and advanced turbine power cycle

    SciTech Connect

    White, D.J.

    1995-10-19

    Solar Turbines, Incorporated (Solar) has a vested interest in the integration of gas turbines and high temperature fuel cells and in particular, solid oxide fuel cells (SOFCs). Solar has identified a parallel path approach to the technology developments needed for future products. The primary approach is to move away from the simple cycle industrial machines of the past and develop as a first step more efficient recuperated engines. This move was prompted by the recognition that the simple cycle machines were rapidly approaching their efficiency limits. Improving the efficiency of simple cycle machines is and will become increasingly more costly. Each efficiency increment will be progressively more costly than the previous step.

  12. Advanced nickel-hydrogen cell configuration study

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Long-term trends in the evolution of space power technology point toward increased payload power demand which in turn translates into both higher battery system charge storage capability and higher operating voltages. State of the art nickel-hydrogen cells of the 50 to 60 Wh size, packaged in individual pressure vessels, are capable of meeting the required cycle life for a wide range of anticipated operating conditions; however, they provided several drawbacks to battery system integrated efforts. Because of size, high voltage/high power systems require integrating hundreds of cells into the operating system. Packaging related weight and volume inefficiencies degrade the energy density and specific energy of individual cells currently at 30 Wh/cudm and 40 Wh/kg respectively. In addition, the increased parts count and associated handling significantly affect the overall battery related costs. Spacecraft battery systems designers within industry and Government realize that to reduce weight, volume, and cost requires increases in the capacity of nickel-hydrogen cells.

  13. High efficiency fuel cell/advanced turbine power cycles

    SciTech Connect

    Morehead, H.

    1995-10-19

    An outline of the Westinghouse high-efficiency fuel cell/advanced turbine power cycle is presented. The following topics are discussed: The Westinghouse SOFC pilot manufacturing facility, cell scale-up plan, pressure effects on SOFC power and efficiency, sureCell versus conventional gas turbine plants, sureCell product line for distributed power applications, 20 MW pressurized-SOFC/gas turbine power plant, 10 MW SOFC/CT power plant, sureCell plant concept design requirements, and Westinghouse SOFC market entry.

  14. Recent advances in cell sheet technology for periodontal regeneration.

    PubMed

    Wang, Jing; Zhang, Rui; Shen, Yun; Xu, Chenyuan; Qi, Shengcai; Lu, Liyan; Wang, Raorao; Xu, Yuanzhi

    2014-05-01

    Tissue engineering has yielded several successes in early clinical trials of regenerative medicine with grafting therapeutic cells seeded into biodegradable scaffolds. However this conventional cell delivery method has limited the field's progress. In recent decades, we have developed a novel cell transferring method, cell sheet technology that allows for controlled attachment and detachment of cells via simple temperature variations of a surface-intelligent temperatureresponsive polymer:poly (N-isopropylacrylamide). It has been widely applied to create functional tissue sheets with cells derived from various tissues to treat a wide range of diseases. Periodontal cell sheets non-invasively harvested from temperature- responsive culture surfaces have been successfully manufactured, resulting in communicative multilayered constructs. Transplantation of cell sheets onto periodontal defects has improved bone and tissue regeneration in animal models and humans and shows low immunogenicity. In this review, we summarize the recent advances of techniques in cell sheet engineering and its application for periodontal regeneration.

  15. Recent advances in sensitized mesoscopic solar cells.

    PubMed

    Grätzel, Michael

    2009-11-17

    Perhaps the largest challenge for our global society is to find ways to replace the slowly but inevitably vanishing fossil fuel supplies by renewable resources and, at the same time, avoid negative effects from the current energy system on climate, environment, and health. The quality of human life to a large degree depends upon the availability of clean energy sources. The worldwide power consumption is expected to double in the next 3 decades because of the increase in world population and the rising demand of energy in the developing countries. This implies enhanced depletion of fossil fuel reserves, leading to further aggravation of the environmental pollution. As a consequence of dwindling resources, a huge power supply gap of 14 terawatts is expected to open up by year 2050 equaling today's entire consumption, thus threatening to create a planetary emergency of gigantic dimensions. Solar energy is expected to play a crucial role as a future energy source. The sun provides about 120,000 terawatts to the earth's surface, which amounts to 6000 times the present rate of the world's energy consumption. However, capturing solar energy and converting it to electricity or chemical fuels, such as hydrogen, at low cost and using abundantly available raw materials remains a huge challenge. Chemistry is expected to make pivotal contributions to identify environmentally friendly solutions to this energy problem. One area of great promise is that of solar converters generally referred to as "organic photovoltaic cells" (OPV) that employ organic constituents for light harvesting or charge carrier transport. While this field is still in its infancy, it is receiving enormous research attention, with the number of publications growing exponentially over the past decade. The advantage of this new generation of solar cells is that they can be produced at low cost, i.e., potentially less than 1 U.S. $/peak watt. Some but not all OPV embodiments can avoid the expensive and energy

  16. Advanced Solar Cell Testing and Characterization

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Curtis, Henry; Piszczor, Michael

    2005-01-01

    The topic for this workshop stems from an ongoing effort by the photovoltaic community and U.S. government to address issues and recent problems associated with solar cells and arrays experienced by a number of different space systems. In April 2003, a workshop session was held at the Aerospace Space Power Workshop to discuss an effort by the Air Force to update and standardize solar cell and array qualification test procedures in an effort to ameliorate some of these problems. The organizers of that workshop session thought it was important to continue these discussions and present this information to the entire photovoltaic community. Thus, it was decided to include this topic as a workshop at the following SPRAT conference.

  17. Advances and Prospect of Nanotechnology in Stem Cells

    NASA Astrophysics Data System (ADS)

    Wang, Zheng; Ruan, Jing; Cui, Daxiang

    2009-07-01

    In recent years, stem cell nanotechnology has emerged as a new exciting field. Theoretical and experimental studies of interaction between nanomaterials or nanostructures and stem cells have made great advances. The importance of nanomaterials, nanostructures, and nanotechnology to the fundamental developments in stem cells-based therapies for injuries and degenerative diseases has been recognized. In particular, the effects of structure and properties of nanomaterials on the proliferation and differentiation of stem cells have become a new interdisciplinary frontier in regeneration medicine and material science. Here we review some of the main advances in this field over the past few years, explore the application prospects, and discuss the issues, approaches and challenges, with the aim of improving application of nanotechnology in the stem cells research and development.

  18. Hall of Fame.

    ERIC Educational Resources Information Center

    El Rancho Unified School District, Pico Rivera, CA.

    A Hall of Fame was established by the El Rancho Unified School District (California) to identify and honor graduates of the school district who have graduated more than 15 years ago, who have achieved recognition in their chosen field, and who would bring honor to the school district in its honoring of them. Nominees for the Hall of Fame were…

  19. The Hall Effect

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The experimental procedure consists of the measurement of the Hall coefficient, resistivity, and Hall mobility as a function of temperature of a sample of gallium arsenides before and after irradiation with low and high energy protons. Work has begun on the development of the theory and subsequently experiments will be designed and performed.

  20. Skyrmions and Hall Transport.

    PubMed

    Kim, Bom Soo; Shapere, Alfred D

    2016-09-01

    We derive a generalized set of Ward identities that captures the effects of topological charge on Hall transport. The Ward identities follow from the (2+1)-dimensional momentum algebra, which includes a central extension proportional to the topological charge density. In the presence of topological objects like Skyrmions, we observe that the central term leads to a direct relation between the thermal Hall conductivity and the topological charge density. We extend this relation to incorporate the effects of a magnetic field and an electric current. The topological charge density produces a distinct signature in the electric Hall conductivity, which is identified in existing experimental data and yields further novel predictions. For insulating materials with translation invariance, the Hall viscosity can be directly determined from the Skyrmion density and the thermal Hall conductivity to be measured as a function of momentum. PMID:27661713

  1. Pulsed hall thruster system

    NASA Technical Reports Server (NTRS)

    Hruby, Vladimir J. (Inventor); Pote, Bruce M. (Inventor); Gamero-Castano, Manuel (Inventor)

    2004-01-01

    A pulsed Hall thruster system includes a Hall thruster having an electron source, a magnetic circuit, and a discharge chamber; a power processing unit for firing the Hall thruster to generate a discharge; a propellant storage and delivery system for providing propellant to the discharge chamber and a control unit for defining a pulse duration .tau.<0.1d.sup.3.rho./m, where d is the characteristic size of the thruster, .rho. is the propellant density at standard conditions, and m is the propellant mass flow rate for operating either the power processing unit to provide to the Hall thruster a power pulse of a pre-selected duration, .tau., or operating the propellant storage and delivery system to provide a propellant flow pulse of duration, .tau., or providing both as pulses, synchronized to arrive coincidentally at the discharge chamber to enable the Hall thruster to produce a discreet output impulse.

  2. Comparability: manufacturing, characterization and controls, report of a UK Regenerative Medicine Platform Pluripotent Stem Cell Platform Workshop, Trinity Hall, Cambridge, 14-15 September 2015.

    PubMed

    Williams, David J; Archer, Richard; Archibald, Peter; Bantounas, Ioannis; Baptista, Ricardo; Barker, Roger; Barry, Jacqueline; Bietrix, Florence; Blair, Nicholas; Braybrook, Julian; Campbell, Jonathan; Canham, Maurice; Chandra, Amit; Foldes, Gabor; Gilmanshin, Rudy; Girard, Mathilde; Gorjup, Erwin; Hewitt, Zöe; Hourd, Paul; Hyllner, Johan; Jesson, Helen; Kee, Jasmin; Kerby, Julie; Kotsopoulou, Nina; Kowalski, Stanley; Leidel, Chris; Marshall, Damian; Masi, Louis; McCall, Mark; McCann, Conor; Medcalf, Nicholas; Moore, Harry; Ozawa, Hiroki; Pan, David; Parmar, Malin; Plant, Anne L; Reinwald, Yvonne; Sebastian, Sujith; Stacey, Glyn; Thomas, Robert J; Thomas, Dave; Thurman-Newell, Jamie; Turner, Marc; Vitillio, Loriana; Wall, Ivan; Wilson, Alison; Wolfrum, Jacqueline; Yang, Ying; Zimmerman, Heiko

    2016-07-01

    This paper summarizes the proceedings of a workshop held at Trinity Hall, Cambridge to discuss comparability and includes additional information and references to related information added subsequently to the workshop. Comparability is the need to demonstrate equivalence of product after a process change; a recent publication states that this 'may be difficult for cell-based medicinal products'. Therefore a well-managed change process is required which needs access to good science and regulatory advice and developers are encouraged to seek help early. The workshop shared current thinking and best practice and allowed the definition of key research questions. The intent of this report is to summarize the key issues and the consensus reached on each of these by the expert delegates.

  3. Comparability: manufacturing, characterization and controls, report of a UK Regenerative Medicine Platform Pluripotent Stem Cell Platform Workshop, Trinity Hall, Cambridge, 14-15 September 2015.

    PubMed

    Williams, David J; Archer, Richard; Archibald, Peter; Bantounas, Ioannis; Baptista, Ricardo; Barker, Roger; Barry, Jacqueline; Bietrix, Florence; Blair, Nicholas; Braybrook, Julian; Campbell, Jonathan; Canham, Maurice; Chandra, Amit; Foldes, Gabor; Gilmanshin, Rudy; Girard, Mathilde; Gorjup, Erwin; Hewitt, Zöe; Hourd, Paul; Hyllner, Johan; Jesson, Helen; Kee, Jasmin; Kerby, Julie; Kotsopoulou, Nina; Kowalski, Stanley; Leidel, Chris; Marshall, Damian; Masi, Louis; McCall, Mark; McCann, Conor; Medcalf, Nicholas; Moore, Harry; Ozawa, Hiroki; Pan, David; Parmar, Malin; Plant, Anne L; Reinwald, Yvonne; Sebastian, Sujith; Stacey, Glyn; Thomas, Robert J; Thomas, Dave; Thurman-Newell, Jamie; Turner, Marc; Vitillio, Loriana; Wall, Ivan; Wilson, Alison; Wolfrum, Jacqueline; Yang, Ying; Zimmerman, Heiko

    2016-07-01

    This paper summarizes the proceedings of a workshop held at Trinity Hall, Cambridge to discuss comparability and includes additional information and references to related information added subsequently to the workshop. Comparability is the need to demonstrate equivalence of product after a process change; a recent publication states that this 'may be difficult for cell-based medicinal products'. Therefore a well-managed change process is required which needs access to good science and regulatory advice and developers are encouraged to seek help early. The workshop shared current thinking and best practice and allowed the definition of key research questions. The intent of this report is to summarize the key issues and the consensus reached on each of these by the expert delegates. PMID:27404768

  4. A particle-in-cell model of the Langmuir probe immersed in Xe plasma under conditions corresponding to those of Hall effect thruster plasma

    NASA Astrophysics Data System (ADS)

    Cenian, Adam; Chernukho, Andrey; Rachubiński, Hubert; Dudeck, Michel

    2014-05-01

    Hall effect thrusters (HETs) are efficient propulsion devices for the station-keeping of geostationary satellites. However, a further efficiency increase requires better knowledge of plasma and plasma-wall interactions. Electric probes are often used for diagnosing HET plasmas but the existing semi-analytical theories, used for the interpretation of probe characteristics, could only be applied with caution. Therefore, in this work a particle-in-cell model of the Langmuir probe immersed in plasma under conditions corresponding to those of HET plasma is developed. It was found that materials with a predominant elastic contribution to secondary electron emission (SEE) will generally lead to lower power deposition on a surface. In the case of inelastic and true SEE processes, the power deposited on a wall depends on the ratio of the sum of secondary electron energies to the electron impact energy. The axial magnetic field also leads to substantial reduction of power deposition on the probe.

  5. 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.

  6. Anomalous Hall effect

    NASA Astrophysics Data System (ADS)

    Nagaosa, Naoto; Sinova, Jairo; Onoda, Shigeki; MacDonald, A. H.; Ong, N. P.

    2010-04-01

    The anomalous Hall effect (AHE) occurs in solids with broken time-reversal symmetry, typically in a ferromagnetic phase, as a consequence of spin-orbit coupling. Experimental and theoretical studies of the AHE are reviewed, focusing on recent developments that have provided a more complete framework for understanding this subtle phenomenon and have, in many instances, replaced controversy by clarity. Synergy between experimental and theoretical works, both playing a crucial role, has been at the heart of these advances. On the theoretical front, the adoption of the Berry-phase concepts has established a link between the AHE and the topological nature of the Hall currents. On the experimental front, new experimental studies of the AHE in transition metals, transition-metal oxides, spinels, pyrochlores, and metallic dilute magnetic semiconductors have established systematic trends. These two developments, in concert with first-principles electronic structure calculations, strongly favor the dominance of an intrinsic Berry-phase-related AHE mechanism in metallic ferromagnets with moderate conductivity. The intrinsic AHE can be expressed in terms of the Berry-phase curvatures and it is therefore an intrinsic quantum-mechanical property of a perfect crystal. An extrinsic mechanism, skew scattering from disorder, tends to dominate the AHE in highly conductive ferromagnets. The full modern semiclassical treatment of the AHE is reviewed which incorporates an anomalous contribution to wave-packet group velocity due to momentum-space Berry curvatures and correctly combines the roles of intrinsic and extrinsic (skew-scattering and side-jump) scattering-related mechanisms. In addition, more rigorous quantum-mechanical treatments based on the Kubo and Keldysh formalisms are reviewed, taking into account multiband effects, and demonstrate the equivalence of all three linear response theories in the metallic regime. Building on results from recent experiment and theory, a

  7. Human umbilical cord blood cells and diabetes mellitus: recent advances.

    PubMed

    Reddi, Alluru S; Kothari, Neil; Kuppasani, Kishore; Ende, Norman

    2015-01-01

    Stem cell therapy for patients with diabetes is an area of great interest to both scientists and clinicians. Human umbilical cord blood cells (HUCBCs) are being increasingly used as a source of stem cells for cell-based therapy for diabetes because these cells can differentiate into pancreatic islet β-cells. Administration of HUCBCs has been shown to lower blood glucose levels in diabetic animal models. The use of autologous HUCBC transfusion in type 1 diabetic children has not shown any benefit. However, "Stem Cell Educator" therapy has shown promise in long term lowering of blood glucose levels in both type 1 and type 2 diabetic patients. In this review, we will briefly discuss recent advances in HUCBC therapy in the treatment of diabetes and some of its complications.

  8. Recent technological advances in thin film solar cells

    SciTech Connect

    Ullal, H.S.; Zwelbel, K.; Surek, T.

    1990-03-01

    High-efficiency, low-cost thin film solar cells are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. This paper reviews the substantial advances made by several thin film solar cell technologies, namely, amorphous silicon, copper indium diselenide, cadmium telluride, and polycrystalline silicon. Recent examples of utility demonstration projects of these emerging materials are also discussed. 8 refs., 4 figs.

  9. Advanced materials for solid oxide fuel cells

    SciTech Connect

    Armstrong, T.R.; Stevenson, J.

    1995-08-01

    The purpose of this research is to improve the properties of the current state-of-the-art materials used for solid oxide fuel cells (SOFCs). The objectives are to: (1) develop materials based on modifications of the state-of-the-art materials; (2) minimize or eliminate stability problems in the cathode, anode, and interconnect; (3) Electrochemically evaluate (in reproducible and controlled laboratory tests) the current state-of-the-art air electrode materials and cathode/electrolyte interfacial properties; (4) Develop accelerated electrochemical test methods to evaluate the performance of SOFCs under controlled and reproducible conditions; and (5) Develop and test materials for use in low-temperature SOFCs. The goal is to modify and improve the current state-of-the-art materials and minimize the total number of cations in each material to avoid negative effects on the materials properties. Materials to reduce potential deleterious interactions, (3) improve thermal, electrical, and electrochemical properties, (4) develop methods to synthesize both state-of-the-art and alternative materials for the simultaneous fabricatoin and consolidation in air of the interconnections and electrodes with the solid electrolyte, and (5) understand electrochemical reactions at materials interfaces and the effects of component composition and processing on those reactions.

  10. Technological advances in real-time tracking of cell death

    PubMed Central

    Skommer, Joanna; Darzynkiewicz, Zbigniew; Wlodkowic, Donald

    2010-01-01

    Cell population can be viewed as a quantum system, which like Schrödinger’s cat exists as a combination of survival- and death-allowing states. Tracking and understanding cell-to-cell variability in processes of high spatio-temporal complexity such as cell death is at the core of current systems biology approaches. As probabilistic modeling tools attempt to impute information inaccessible by current experimental approaches, advances in technologies for single-cell imaging and omics (proteomics, genomics, metabolomics) should go hand in hand with the computational efforts. Over the last few years we have made exciting technological advances that allow studies of cell death dynamically in real-time and with the unprecedented accuracy. These approaches are based on innovative fluorescent assays and recombinant proteins, bioelectrical properties of cells, and more recently also on state-of-the-art optical spectroscopy. Here, we review current status of the most innovative analytical technologies for dynamic tracking of cell death, and address the interdisciplinary promises and future challenges of these methods. PMID:20519963

  11. Advances in targeting cell surface signalling molecules for immune modulation

    PubMed Central

    Yao, Sheng; Zhu, Yuwen; Chen, Lieping

    2013-01-01

    The past decade has witnessed a surge in the development of immunomodulatory approaches to combat a broad range of human diseases, including cancer, viral infections, autoimmunity and inflammation as well as in the prevention of transplant rejection. Immunomodulatory approaches mostly involve the use of monoclonal antibodies or recombinant fusion proteins that target cell surface signalling molecules on immune cells to drive immune responses towards the desired direction. Advances in our understanding of the human immune system, along with valuable lessons learned from the first generation of therapeutic biologics, are aiding the design of the next generation of immunomodulatory biologics with better therapeutic efficacy, minimized adverse effects and long-lasting clinical benefit. The recent encouraging results from antibodies targeting programmed cell death protein 1 (PD1) and B7 homolog 1 (B7H1; also known as PDL1) for the treatment of various advanced human cancers show that immunomodulatory therapy has come of age. PMID:23370250

  12. Advanced technology for extended endurance alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Martin, R. A.

    1987-01-01

    Advanced components have been developed for alkaline fuel cells with a view to the satisfaction of NASA Space Station design requirements for extended endurance. The components include a platinum-on-carbon catalyst anode, a potassium titanate-bonded electrolyte matrix, a lightweight graphite electrolyte reservoir plate, a gold-plated nickel-perforated foil electrode substrate, a polyphenylene sulfide cell edge frame material, and a nonmagnesium cooler concept. When incorporated into the alkaline fuel cell unit, these components are expected to yield regenerative operation in a low earth orbit Space Station with a design life greater than 5 years.

  13. Advances in sickle cell therapies in the hydroxyurea era.

    PubMed

    Field, Joshua J; Nathan, David G

    2014-01-01

    In the hydroxyurea era, insights into mechanisms downstream of erythrocyte sickling have led to new therapeutic approaches for patients with sickle cell disease (SCD). Therapies have been developed that target vascular adhesion, inflammation and hemolysis, including innovative biologics directed against P-selectin and invariant natural killer T cells. Advances in hematopoietic stem cell transplant and gene therapy may also provide more opportunities for cures in the near future. Several clinical studies are underway to determine the safety and efficacy of these new treatments. Novel approaches to treat SCD are desperately needed, since current therapies are limited and rates of morbidity and mortality remain high. PMID:25549232

  14. Facility Focus: Residence Halls.

    ERIC Educational Resources Information Center

    College Planning & Management, 1999

    1999-01-01

    Describes four college residence halls that have successfully combined a comfortable, aesthetically pleasing, and socially stimulating atmosphere for its residents. Photographs and interior-design line drawings are included. (GR)

  15. Hall viscosity of hierarchical quantum Hall states

    NASA Astrophysics Data System (ADS)

    Fremling, Mikael; Hansson, Thors Hans; Suorsa, Juha

    2015-03-01

    We construct model wave functions on a torus for all chiral states in the abelian quantum Hall hierarchy. These functions have no variational parameters, and they transform under the modular group in the same way as the multicomponent generalizations of the Laughlin wave functions. Assuming the absence of Berry phases upon adiabatic variations of the modular parameter τ, we calculate the quantum Hall viscosity and find it to be in agreement with the formula, given by Read, which relates the viscosity to the average orbital spin of the electrons. For the filling factor ν = 2 / 5 Jain state, which is at the second level in the hierarchy, we compare our model wave function with the numerically obtained ground state of the Coulomb interaction Hamiltonian in the lowest Landau level, and find very good agreement in a large region of the complex τ-plane. For the same example, we also numerically compute the Hall viscosity and find good agreement with the analytical result for both the model wave function and the numerically obtained Coulomb wave function. We argue that this supports the notion of a generalized plasma analogy that would ensure that wave functions obtained using conformal field theory methods do not acquire Berry phases upon adiabatic evolution.

  16. Advances in cell surface glycoengineering reveal biological function.

    PubMed

    Nischan, Nicole; Kohler, Jennifer J

    2016-08-01

    Cell surface glycans are critical mediators of cell-cell, cell-ligand, and cell-pathogen interactions. By controlling the set of glycans displayed on the surface of a cell, it is possible to gain insight into the biological functions of glycans. Moreover, control of glycan expression can be used to direct cellular behavior. While genetic approaches to manipulate glycosyltransferase gene expression are available, their utility in glycan engineering has limitations due to the combinatorial nature of glycan biosynthesis and the functional redundancy of glycosyltransferase genes. Biochemical and chemical strategies offer valuable complements to these genetic approaches, notably by enabling introduction of unnatural functionalities, such as fluorophores, into cell surface glycans. Here, we describe some of the most recent developments in glycoengineering of cell surfaces, with an emphasis on strategies that employ novel chemical reagents. We highlight key examples of how these advances in cell surface glycan engineering enable study of cell surface glycans and their function. Exciting new technologies include synthetic lipid-glycans, new chemical reporters for metabolic oligosaccharide engineering to allow tandem and in vivo labeling of glycans, improved chemical and enzymatic methods for glycoproteomics, and metabolic glycosyltransferase inhibitors. Many chemical and biochemical reagents for glycan engineering are commercially available, facilitating their adoption by the biological community.

  17. Recent advances in high-performance direct methanol fuel cells

    SciTech Connect

    Narayanan, S.R.; Chun, W.; Valdez, T.I.

    1996-12-31

    Direct methanol fuel cells for portable power applications have been advanced significantly under DARPA- and ARO-sponsored programs over the last five years. A liquid-feed direct methanol fuel cell developed under these programs, employs a proton exchange membrane as electrolyte and operates on aqueous solutions of methanol with air or oxygen as the oxidant. Power densities as high as 320 mW/cm{sup 2} have been demonstrated. Demonstration of five-cell stack based on the liquid-feed concept have been successfully performed by Giner Inc. and the Jet Propulsion Laboratory. Over 2000 hours of life-testing have been completed on these stacks. These fuel cells have been also been demonstrated by USC to operate on alternate fuels such as trimethoxymethane, dimethoxymethane and trioxane. Reduction in the parasitic loss of fuel across the fuel cell, a phenomenon termed as {open_quotes}fuel crossover{close_quotes} has been achieved using polymer membranes developed at USC. As a result efficiencies as high as 40% is considered attainable with this type of fuel cell. The state-of-development has reached a point where it is now been actively considered for stationary, portable and transportation applications. The research and development issues have been the subject of several previous articles and the present article is an attempt to summarize the key advances in this technology.

  18. Analysis of circulating tumor cells derived from advanced gastric cancer.

    PubMed

    Toyoshima, Kosei; Hayashi, Akira; Kashiwagi, Masahide; Hayashi, Naoko; Iwatsuki, Masaaki; Ishimoto, Takatsugu; Baba, Yoshifumi; Baba, Hideo; Ohta, Yoshikazu

    2015-08-15

    Studies in circulating tumor cells (CTCs) have proceeded to be accepted as prognostic markers in several types of cancers. But they are still limited because many are mainly from enumeration of CTCs. Here, we tried to evaluate the tumorigenicity of CTCs from advanced gastric cancer patients (n = 42). Peripheral blood mononuclear cells (PBMC) from the patients were separated into CD45 negative and positive fractions and both were subcutaneously injected into immunodeficient mice. Within 5 months nine tumor-like-structures from six patients but not from healthy volunteers were established. They were durable for passages and all had been confirmed human origin. Eight of the nine tumor-like-structures were from nonauthorized CTC containing cells expressing CD45 and B-cell markers. On the contrary, one of them was developed from CD45(-) PBMC fraction of a patient with bone marrow metastasis reflecting authorized CTCs. Histopathology showed common features with that of original gastric tumor. The cells isolated from the tumor-like-structure expressed EpCAM and CEA further supporting they were from the original tumor. Moreover the cells were CD44 positive to varying degree and a limiting dilution study showed that the CD44(+/high) fraction had tumorigenicity. The CD44 was dominantly in the form of CD44 variant 8-10. The CD44(+/high) cells had higher expression of the glutamate/cysteine transporter xCT compared with the CD44(-/low) cells. Our results showed the existence of tumor-initiating cells in blood of advanced gastric cancer patients and they could be a therapeutic target and prospective tool for further investigations.

  19. Recent advances in solid polymer electrolyte fuel cell technology

    SciTech Connect

    Ticianelli, E.A.; Srinivasan, S.; Gonzalez, E.R.

    1988-01-01

    With methods used to advance solid polymer electrolyte fuel cell technology, we are close to obtaining the goal of 1 A/cm/sup 2/ at 0.7. Higher power densities have been reported (2 A/cm/sup 2/ at 0.5 V) but only with high catalyst loading electrodes (2 mg/cm/sup 2/ and 4 mg/cm/sup 2/ at anode and cathode, respectively) and using a Dow membrane with a better conductivity and water retention characteristics. Work is in progress to ascertain performances of cells with Dow membrane impregnated electrodes and Dow membrane electrolytes. 5 refs., 6 figs.

  20. [Hormonal therapy of advanced or relapsed ovarian granulosa cell tumor].

    PubMed

    Sun, H; Bai, P

    2016-07-01

    Ovarian granulosa cell tumor is a rare gynecologic malignancy with hormonal activity. Surgical excision is the standard treatment for this disease. Most patients present excellent short term prognosis, however, late relapse often occurs, even after many years. Viable treatments of advanced or relapsed granulosa cell tumor are still limited, and the optimal therapy method has not been established. Compared with chemotherapy and radiotherapy, hormonal therapy is a well-tolerated treatment which can be administrated over a long period of time without serious side effects, and the combined application of hormones may achieve a better outcome. Therefore, hormonal therapy has been suggested as a potential treatment option for patients with advanced or relapsed granulosa cell tumor, and to extend the tumor-free interval and attenuate the disease progression. Future researches should be focused on the identification of the hormonal therapy which may provide the greatest clinical benefit, comparing and analyzing the effects of different combined therapeutic regimens of hormone drugs, and on the synthesis of drugs highly activating estrogen receptor β expressed in the granulosa cell tumor cells. PMID:27531259

  1. Advanced designs for IPV nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.; Manzo, M. A.; Gonzalez-Sanabria, O. D.

    1984-01-01

    Advanced designs for individual pressure vessel nickel-hydrogen cells have been concieved which should improve the cycle life at deep depths-of-discharge. Features of the designs which are new and not incorporated in either of the contemporary cells (Air Force/Hughes, Comsat) are: (1) use of alternate methods of oxygen recombination, (2) use of serrated edge separators to facilitate movement of gas within the cell while still maintaining required physical contact with the wall wick, and (3) use of an expandable stack to accommodate some of the nickel electrode expansion. The designs also consider electrolyte volume requirements over the life of the cells, and are fully compatible with the Air Force/Hughes design.

  2. Advancements in stem cells treatment of skeletal muscle wasting

    PubMed Central

    Meregalli, Mirella; Farini, Andrea; Sitzia, Clementina; Torrente, Yvan

    2014-01-01

    Muscular dystrophies (MDs) are a heterogeneous group of inherited disorders, in which progressive muscle wasting and weakness is often associated with exhaustion of muscle regeneration potential. Although physiological properties of skeletal muscle tissue are now well known, no treatments are effective for these diseases. Muscle regeneration was attempted by means transplantation of myogenic cells (from myoblast to embryonic stem cells) and also by interfering with the malignant processes that originate in pathological tissues, such as uncontrolled fibrosis and inflammation. Taking into account the advances in the isolation of new subpopulation of stem cells and in the creation of artificial stem cell niches, we discuss how these emerging technologies offer great promises for therapeutic approaches to muscle diseases and muscle wasting associated with aging. PMID:24575052

  3. [Advances in Lung Stem Cells and Lung Cancer Stem Cells].

    PubMed

    Yin, Huijing; Deng, Jiong

    2015-10-20

    Cancer stem cells (CSCs) are emerging as a hot topic for cancer research. Lung CSCs share many characteristics with normal lung stem cells (SCs), including self-renewal and multi-potency for differentiation. Many molecular markers expressed in various types of CSCs were also found in lung CSCs, such as CD133, CD44, aldehyde dehydrogenase (ALDH) and ATP-binding cassette sub-family G member 2 (ABCG2). Similarly, proliferation and expansion of lung CSCs are regulated not only by signal transduction pathways functioning in normal lung SCs, such as Notch, Hedgehog and Wnt pathways, but also by those acting in tumor cells, such as epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT3) and phosphatidylinositol 3 kinase (PI3K) pathways. As CSC plays an critical role in tumor recurrence, metastasis and drug-resistance, understanding the difference between lung CSCs and normal lung SCs, identifying and targeting CSC markers or related signaling pathways may increase the efficacy of therapy on lung cancer and improved survival of lung cancer patients.

  4. Assessment of Research Needs for Advanced Fuel Cells

    SciTech Connect

    Penner, S.S.

    1985-11-01

    The DOE Advanced Fuel Cell Working Group (AFCWG) was formed and asked to perform a scientific evaluation of the current status of fuel cells, with emphasis on identification of long-range research that may have a significant impact on the practical utilization of fuel cells in a variety of applications. The AFCWG held six meetings at locations throughout the country where fuel cell research and development are in progress, for presentations by experts on the status of fuel cell research and development efforts, as well as for inputs on research needs. Subsequent discussions by the AFCWG have resulted in the identification of priority research areas that should be explored over the long term in order to advance the design and performance of fuel cells of all types. Surveys describing the salient features of individual fuel cell types are presented in Chapters 2 to 6 and include elaborations of long-term research needs relating to the expeditious introduction of improved fuel cells. The Introduction and the Summary (Chapter 1) were prepared by AFCWG. They were repeatedly revised in response to comments and criticism. The present version represents the closest approach to a consensus that we were able to reach, which should not be interpreted to mean that each member of AFCWG endorses every statement and every unexpressed deletion. The Introduction and Summary always represent a majority view and, occasionally, a unanimous judgment. Chapters 2 to 6 provide background information and carry the names of identified authors. The identified authors of Chapters 2 to 6, rather than AFCWG as a whole, bear full responsibility for the scientific and technical contents of these chapters.

  5. Recent advances in Echinococcus genomics and stem cell research.

    PubMed

    Koziol, U; Brehm, K

    2015-10-30

    Alveolar and cystic echinococcosis, caused by the metacestode larval stages of the tapeworms Echinococcus multilocularis and Echinococcus granulosus, respectively, are life-threatening diseases and very difficult to treat. The introduction of benzimidazole-based chemotherapy, which targets parasite β-tubulin, has significantly improved the life-span and prognosis of echinococcosis patients. However, benzimidazoles show only parasitostatic activity, are associated with serious adverse side effects and have to be administered for very long time periods, underlining the need for new drugs. Very recently, the nuclear genomes of E. multilocularis and E. granulosus have been characterised, revealing a plethora of data for gaining a deeper understanding of host-parasite interaction, parasite development and parasite evolution. Combined with extensive transcriptome analyses of Echinococcus life cycle stages these investigations also yielded novel clues for targeted drug design. Recent years also witnessed significant advancements in the molecular and cellular characterisation of the Echinococcus 'germinative cell' population, which forms a unique stem cell system that differs from stem cells of other organisms in the expression of several genes associated with the maintenance of pluripotency. As the only parasite cell type capable of undergoing mitosis, the germinative cells are central to all developmental transitions of Echinococcus within the host and to parasite expansion via asexual proliferation. In the present article, we will briefly introduce and discuss recent advances in Echinococcus genomics and stem cell research in the context of drug design and development. Interestingly, it turns out that benzimidazoles seem to have very limited effects on Echinococcus germinative cells, which could explain the high recurrence rates observed after chemotherapeutic treatment of echinococcosis patients. This clearly indicates that future efforts into the development of

  6. Recent advances in Echinococcus genomics and stem cell research.

    PubMed

    Koziol, U; Brehm, K

    2015-10-30

    Alveolar and cystic echinococcosis, caused by the metacestode larval stages of the tapeworms Echinococcus multilocularis and Echinococcus granulosus, respectively, are life-threatening diseases and very difficult to treat. The introduction of benzimidazole-based chemotherapy, which targets parasite β-tubulin, has significantly improved the life-span and prognosis of echinococcosis patients. However, benzimidazoles show only parasitostatic activity, are associated with serious adverse side effects and have to be administered for very long time periods, underlining the need for new drugs. Very recently, the nuclear genomes of E. multilocularis and E. granulosus have been characterised, revealing a plethora of data for gaining a deeper understanding of host-parasite interaction, parasite development and parasite evolution. Combined with extensive transcriptome analyses of Echinococcus life cycle stages these investigations also yielded novel clues for targeted drug design. Recent years also witnessed significant advancements in the molecular and cellular characterisation of the Echinococcus 'germinative cell' population, which forms a unique stem cell system that differs from stem cells of other organisms in the expression of several genes associated with the maintenance of pluripotency. As the only parasite cell type capable of undergoing mitosis, the germinative cells are central to all developmental transitions of Echinococcus within the host and to parasite expansion via asexual proliferation. In the present article, we will briefly introduce and discuss recent advances in Echinococcus genomics and stem cell research in the context of drug design and development. Interestingly, it turns out that benzimidazoles seem to have very limited effects on Echinococcus germinative cells, which could explain the high recurrence rates observed after chemotherapeutic treatment of echinococcosis patients. This clearly indicates that future efforts into the development of

  7. 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.

  8. Advances in genetic modification of pluripotent stem cells.

    PubMed

    Fontes, Andrew; Lakshmipathy, Uma

    2013-11-15

    Genetically engineered stem cells aid in dissecting basic cell function and are valuable tools for drug discovery, in vivo cell tracking, and gene therapy. Gene transfer into pluripotent stem cells has been a challenge due to their intrinsic feature of growing in clusters and hence not amenable to common gene delivery methods. Several advances have been made in the rapid assembly of DNA elements, optimization of culture conditions, and DNA delivery methods. This has lead to the development of viral and non-viral methods for transient or stable modification of cells, albeit with varying efficiencies. Most methods require selection and clonal expansion that demand prolonged culture and are not suited for cells with limited proliferative potential. Choosing the right platform based on preferred length, strength, and context of transgene expression is a critical step. Random integration of the transgene into the genome can be complicated due to silencing or altered regulation of expression due to genomic effects. An alternative to this are site-specific methods that target transgenes followed by screening to identify the genomic loci that support long-term expression with stem cell proliferation and differentiation. A highly precise and accurate editing of the genome driven by homology can be achieved using traditional methods as well as the newer technologies such as zinc finger nuclease, TAL effector nucleases and CRISPR. In this review, we summarize the different genetic engineering methods that have been successfully used to create modified embryonic and induced pluripotent stem cells.

  9. Inside Single Cells: Quantitative Analysis with Advanced Optics and Nanomaterials

    PubMed Central

    Cui, Yi; Irudayaraj, Joseph

    2014-01-01

    Single cell explorations offer a unique window to inspect molecules and events relevant to mechanisms and heterogeneity constituting the central dogma of biology. A large number of nucleic acids, proteins, metabolites and small molecules are involved in determining and fine-tuning the state and function of a single cell at a given time point. Advanced optical platforms and nanotools provide tremendous opportunities to probe intracellular components with single-molecule accuracy, as well as promising tools to adjust single cell activity. In order to obtain quantitative information (e.g. molecular quantity, kinetics and stoichiometry) within an intact cell, achieving the observation with comparable spatiotemporal resolution is a challenge. For single cell studies both the method of detection and the biocompatibility are critical factors as they determine the feasibility, especially when considering live cell analysis. Although a considerable proportion of single cell methodologies depend on specialized expertise and expensive instruments, it is our expectation that the information content and implication will outweigh the costs given the impact on life science enabled by single cell analysis. PMID:25430077

  10. Advanced Cell Culture Techniques for Cancer Drug Discovery

    PubMed Central

    Lovitt, Carrie J.; Shelper, Todd B.; Avery, Vicky M.

    2014-01-01

    Human cancer cell lines are an integral part of drug discovery practices. However, modeling the complexity of cancer utilizing these cell lines on standard plastic substrata, does not accurately represent the tumor microenvironment. Research into developing advanced tumor cell culture models in a three-dimensional (3D) architecture that more prescisely characterizes the disease state have been undertaken by a number of laboratories around the world. These 3D cell culture models are particularly beneficial for investigating mechanistic processes and drug resistance in tumor cells. In addition, a range of molecular mechanisms deconstructed by studying cancer cells in 3D models suggest that tumor cells cultured in two-dimensional monolayer conditions do not respond to cancer therapeutics/compounds in a similar manner. Recent studies have demonstrated the potential of utilizing 3D cell culture models in drug discovery programs; however, it is evident that further research is required for the development of more complex models that incorporate the majority of the cellular and physical properties of a tumor. PMID:24887773

  11. Breast cancer stem cells: current advances and clinical implications.

    PubMed

    Luo, Ming; Clouthier, Shawn G; Deol, Yadwinder; Liu, Suling; Nagrath, Sunitha; Azizi, Ebrahim; Wicha, Max S

    2015-01-01

    There is substantial evidence that many cancers, including breast cancer, are driven by a population of cells that display stem cell properties. These cells, termed cancer stem cells (CSCs) or tumor initiating cells, not only drive tumor initiation and growth but also mediate tumor metastasis and therapeutic resistance. In this chapter, we summarize current advances in CSC research with a major focus on breast CSCs (BCSCs). We review the prevailing methods to isolate and characterize BCSCs and recent evidence documenting their cellular origins and phenotypic plasticity that enables them to transition between mesenchymal and epithelial-like states. We describe in vitro and clinical evidence that these cells mediate metastasis and treatment resistance in breast cancer, the development of novel strategies to isolate circulating tumor cells (CTCs) that contain CSCs and the use of patient-derived xenograft (PDX) models in preclinical breast cancer research. Lastly, we highlight several signaling pathways that regulate BCSC self-renewal and describe clinical implications of targeting these cells for breast cancer treatment. The development of strategies to effectively target BCSCs has the potential to significantly improve the outcomes for patients with breast cancer.

  12. Recent advances in bone regeneration using adult stem cells.

    PubMed

    Zigdon-Giladi, Hadar; Rudich, Utai; Michaeli Geller, Gal; Evron, Ayelet

    2015-04-26

    Bone is a highly vascularized tissue reliant on the close spatial and temporal association between blood vessels and bone cells. Therefore, cells that participate in vasculogenesis and osteogenesis play a pivotal role in bone formation during prenatal and postnatal periods. Nevertheless, spontaneous healing of bone fracture is occasionally impaired due to insufficient blood and cellular supply to the site of injury. In these cases, bone regeneration process is interrupted, which might result in delayed union or even nonunion of the fracture. Nonunion fracture is difficult to treat and have a high financial impact. In the last decade, numerous technological advancements in bone tissue engineering and cell-therapy opened new horizon in the field of bone regeneration. This review starts with presentation of the biological processes involved in bone development, bone remodeling, fracture healing process and the microenvironment at bone healing sites. Then, we discuss the rationale for using adult stem cells and listed the characteristics of the available cells for bone regeneration. The mechanism of action and epigenetic regulations for osteogenic differentiation are also described. Finally, we review the literature for translational and clinical trials that investigated the use of adult stem cells (mesenchymal stem cells, endothelial progenitor cells and CD34(+) blood progenitors) for bone regeneration.

  13. Advances in haploidentical stem cell transplantation for hematologic malignancies.

    PubMed

    Montoro, Juan; Sanz, Jaime; Sanz, Guillermo F; Sanz, Miguel A

    2016-08-01

    One of the most important advances in allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the use of alternative donors and cell sources, such as haploidentical transplants (haplo-HSCT) from family donors. Several approaches have been developed to overcome the challenging bidirectional alloreactivity. We discuss these approaches, including ex vivo T-cell-depleted grafts with megadose of CD34(+) cells, not requiring immunosuppression after allogeneic transplantation for graft-versus-host disease (GVHD) prophylaxis, and other strategies using unmanipulated T-cell-replete grafts with intensive immunosuppression or post-transplantation cyclophosphamide to minimize the GVHD. We also address the role of other strategies developed in the context of the haplo-HSCT platforms, such as ex vivo selective depletion of alloreactive donor T-cell subpopulations, infusion of antigen-specific T-cells against several pathogens, and infusion of regulatory T-cells, among other experimental approaches. Finally, some considerations about the selection of the most suitable donor, when more than one family member is available, are also addressed.

  14. Nonlocal Anomalous Hall Effect

    NASA Astrophysics Data System (ADS)

    Zhang, Steven S.-L.; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect—the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt /YIG structures.

  15. Nonlocal Anomalous Hall Effect.

    PubMed

    Zhang, Steven S-L; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect-the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt/YIG structures.

  16. Advanced Lithium-Ion Cell Development for NASA's Constellation Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.; Miller, Thomas B.; Manzo, Michelle A.; Mercer, Carolyn R.

    2008-01-01

    The Energy Storage Project of NASA s Exploration Technology Development Program is developing advanced lithium-ion batteries to meet the requirements for specific Constellation missions. NASA GRC, in conjunction with JPL and JSC, is leading efforts to develop High Energy and Ultra High Energy cells for three primary Constellation customers: Altair, Extravehicular Activities (EVA), and Lunar Surface Systems. The objective of the High Energy cell development is to enable a battery system that can operationally deliver approximately 150 Wh/kg for 2000 cycles. The Ultra High Energy cell development will enable a battery system that can operationally deliver 220 Wh/kg for 200 cycles. To accomplish these goals, cathode, electrolyte, separator, and safety components are being developed for High Energy Cells. The Ultra High Energy cell development adds lithium alloy anodes to the component development portfolio to enable much higher cell-level specific energy. The Ultra High Energy cell development is targeted for the ascent stage of Altair, which is the Lunar Lander, and for power for the Portable Life support System of the EVA Lunar spacesuit. For these missions, mass is highly critical, but only a limited number of cycles are required. The High Energy cell development is primarily targeted for Mobility Systems (rovers) for Lunar Surface Systems, however, due to the high risk nature of the Ultra High Energy cell development, the High Energy cell will also serve as a backup technology for Altair and EVA. This paper will discuss mission requirements and the goals of the material, component, and cell development efforts in further detail.

  17. Model of Hall Reconnection

    SciTech Connect

    Malyshkin, Leonid M.

    2008-11-28

    The rate of quasistationary, two-dimensional magnetic reconnection is calculated in the framework of incompressible Hall magnetohydrodynamics, which includes the Hall and electron pressure terms in Ohm's law. The Hall-magnetohydrodynamics equations are solved in a local region across the reconnection electron layer, including only the upstream region and the layer center. In the case when the ion inertial length d{sub i} is larger than the Sweet-Parker reconnection layer thickness, the dimensionless reconnection rate is found to be independent of the electrical resistivity and equal to d{sub i}/L, where L is the scale length of the external magnetic field in the upstream region outside the electron layer and the ion layer thickness is found to be d{sub i}.

  18. High Power Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Jankovsky, Robert; Tverdokhlebov, Sergery; Manzella, David

    1999-01-01

    The development of Hall thrusters with powers ranging from tens of kilowatts to in excess of one hundred kilowatts is considered based on renewed interest in high power. high thrust electric propulsion applications. An approach to develop such thrusters based on previous experience is discussed. It is shown that the previous experimental data taken with thrusters of 10 kW input power and less can be used. Potential mass savings due to the design of high power Hall thrusters are discussed. Both xenon and alternate thruster propellant are considered, as are technological issues that will challenge the design of high power Hall thrusters. Finally, the implications of such a development effort with regard to ground testing and spacecraft intecrati'on issues are discussed.

  19. Advanced Silicon Solar Cell Device Physics and Design

    NASA Astrophysics Data System (ADS)

    Deceglie, Michael Gardner

    A fundamental challenge in the development and deployment of solar photovoltaic technology is a reduction in cost enabling direct competition with fossil-fuel-based energy sources. A key driver in this cost reduction is optimized device efficiency, because increased energy output leverages all photovoltaic system costs, from raw materials and module manufacturing to installation and maintenance. To continue progress toward higher conversion efficiencies, solar cells are being fabricated with increasingly complex designs, including engineered nanostructures, heterojunctions, and novel contacting and passivation schemes. Such advanced designs require a comprehensive and unified understanding of the optical and electrical device physics at the microscopic scale. This thesis focuses on a microscopic understanding of solar cell optoelectronic performance and its impact on cell optimization. We consider this in three solar cell platforms: thin-film crystalline silicon, amorphous/crystalline silicon heterojunctions, and thin-film cells with nanophotonic light trapping. The work described in this thesis represents a powerful design paradigm, based on a detailed physical understanding of the mechanisms governing solar cell performance. Furthermore, we demonstrate the importance of understanding not just the individual mechanisms, but also their interactions. Such an approach to device optimization is critical for the efficiency and competitiveness of future generations of solar cells.

  20. Advances in stem cell therapy for cardiovascular disease (Review).

    PubMed

    Sun, Rongrong; Li, Xianchi; Liu, Min; Zeng, Yi; Chen, Shuang; Zhang, Peying

    2016-07-01

    Cardiovascular disease constitutes the primary cause of mortality and morbidity worldwide, and represents a group of disorders associated with the loss of cardiac function. Despite considerable advances in the understanding of the pathologic mechanisms of the disease, the majority of the currently available therapies remain at best palliative, since the problem of cardiac tissue loss has not yet been addressed. Indeed, few therapeutic approaches offer direct tissue repair and regeneration, whereas the majority of treatment options aim to limit scar formation and adverse remodeling, while improving myocardial function. Of all the existing therapeutic approaches, the problem of cardiac tissue loss is addressed uniquely by heart transplantation. Nevertheless, alternative options, particularly stem cell therapy, has emerged as a novel and promising approach. This approach involves the transplantation of healthy and functional cells to promote the renewal of damaged cells and repair injured tissue. Bone marrow precursor cells were the first cell type used in clinical studies, and subsequently, preclinical and clinical investigations have been extended to the use of various populations of stem cells. This review addresses the present state of research as regards stem cell therapy for cardiovascular disease.

  1. Advanced fuel cell development. Progress report, October-December 1979

    SciTech Connect

    Pierce, R. D.; Kucera, G. H.; Kupperman, D. S.; Poeppel, R. B.; Sim, J. W.; Singh, R. N.; Smith, J. L.

    1980-05-01

    Advanced fuel cell research and development activities at Argonne National Laboratory (ANL) during the period October-December 1979 are described. These efforts have been directed toward understanding and improving components of molten carbonate fuel cells and have included operation of 10-cm square cells. The principal focus has been on the development of electrolyte structures (LiAlO/sub 2/ and Li/sub 2/CO/sub 3/-K/sub 2/CO/sub 3/) that have good electrolyte retention and mechanical properties as well as long-term stability. This effort included work on preparation of sintered LiAlO/sub 2/ as electrolyte support, use of a scanning laser acoustic microscope to evaluate electrolyte structures, and measurements of the thermal expansion coefficients of various mixtures of ..beta..-LiAlO/sub 2/ and carbonate eutectic.

  2. Hall Effect in a Plasma.

    ERIC Educational Resources Information Center

    Kunkel, W. B.

    1981-01-01

    Describes an apparatus and procedure for conducting an undergraduate laboratory experiment to quantitatively study the Hall effect in a plasma. Includes background information on the Hall effect and rationale for conducting the experiment. (JN)

  3. Chemotherapy for Advanced Non-small Cell Lung Cancer.

    PubMed

    Dietrich, Martin F; Gerber, David E

    2016-01-01

    Non-small cell lung cancer has seen an unprecedented augmentation of therapeutic options over the last couple of years. Improved understanding of molecular drivers and the role of the immune system in cancer therapy have brought new drugs to the armamentarium. Despite these advances, cytotoxic chemotherapy remains a substantial part of therapy for most patients in locally advanced and metastatic stage. Initially thought to be a chemotherapy-resistant entity, meta-analyses in the mid-1990s demonstrated modest efficacy of platinum-based therapy. Further combination trials demonstrated enhanced efficacy for several regimen in first and second lines, including the introduction of antimetabolites, taxanes, and anti-angiogenic agents. Maintenance chemotherapy has been another novel, successful approach for management of metastatic disease. Herein, we summarize the current concepts of chemotherapy, its applicability to the different histologies, and novel concepts of therapy. PMID:27535392

  4. Treatment of advanced non-small cell lung cancer.

    PubMed

    De Petris, L; Crinò, L; Scagliotti, G V; Gridelli, C; Galetta, D; Metro, G; Novello, S; Maione, P; Colucci, G; de Marinis, F

    2006-03-01

    In the last decade the treatment of advanced-metastatic non-small cell lung cancer has substantially improved. If in the early 90s there was still concern about the real efficacy of chemotherapy over best suppotive care alone in the advanced setting, constant developments in clinical research have demonstrated the survival advantage of active anti-cancer drugs not only in the first-line setting, but, lately, even in patients with recurrent disease after failure of two previous chemotherapy lines. With the premises of high throughput technologies, translational research is aiming to characterize patients and tumors on a molecular basis. With pharmacogenomics it would then be possible to accurately predict patient outcome and tailor the treatment strategy according to the geno-phenotype of single patients.

  5. Advances and challenges in the differentiation of pluripotent stem cells into pancreatic β cells.

    PubMed

    Abdelalim, Essam M; Emara, Mohamed M

    2015-01-26

    Pluripotent stem cells (PSCs) are able to differentiate into several cell types, including pancreatic β cells. Differentiation of pancreatic β cells depends on certain transcription factors, which function in a coordinated way during pancreas development. The existing protocols for in vitro differentiation produce pancreatic β cells, which are not highly responsive to glucose stimulation except after their transplantation into immune-compromised mice and allowing several weeks for further differentiation to ensure the maturation of these cells in vivo. Thus, although the substantial improvement that has been made for the differentiation of induced PSCs and embryonic stem cells toward pancreatic β cells, several challenges still hindering their full generation. Here, we summarize recent advances in the differentiation of PSCs into pancreatic β cells and discuss the challenges facing their differentiation as well as the different applications of these potential PSC-derived β cells.

  6. Advances in Li-TiS2 cell technology

    NASA Technical Reports Server (NTRS)

    Surampudi, S.; Shen, D. H.; Huang, C.-K.; Deligiannis, F.; Attia, A. I.; Halpert, G.

    1991-01-01

    Jet Propulsion Laboratories (JPL) is involved in a NASA sponsored program to develop ambient temperature secondary cells for future space missions. After several years of research on various cathode materials, titanium disulfide (TiS2) was selected in view of its intrinsic reversibility and high faradaic utilization. In the last two years, the efforts were focussed on improving the cycle life of the system and developing 1 Ah cells. Several approaches including the use of mixed solvent electrolytes, the operation of cells at low temperature, and the cycling of cells under different voltage limits, were initially examined to improve the cycle life performance of the Li/TiS2 system. Spiral wound 1 Ah cells fabricated incorporating the improvements from the above studies have delivered more than 600 cycles at 50 percent depth of discharge (DOD). Work is in progress to identify alternate anode materials that can improve the cycle life of the cells to 1000 cycles at 50 percent DOD. The advances made in the Li/TiS2 technology at JPL since 1989 are summarized.

  7. Advances in Li-TiS2 cell technology

    NASA Astrophysics Data System (ADS)

    Surampudi, S.; Shen, D. H.; Huang, C.-K.; Deligiannis, F.; Attia, A. I.; Halpert, G.

    1991-09-01

    Jet Propulsion Laboratories (JPL) is involved in a NASA sponsored program to develop ambient temperature secondary cells for future space missions. After several years of research on various cathode materials, titanium disulfide (TiS2) was selected in view of its intrinsic reversibility and high faradaic utilization. In the last two years, the efforts were focussed on improving the cycle life of the system and developing 1 Ah cells. Several approaches including the use of mixed solvent electrolytes, the operation of cells at low temperature, and the cycling of cells under different voltage limits, were initially examined to improve the cycle life performance of the Li/TiS2 system. Spiral wound 1 Ah cells fabricated incorporating the improvements from the above studies have delivered more than 600 cycles at 50 percent depth of discharge (DOD). Work is in progress to identify alternate anode materials that can improve the cycle life of the cells to 1000 cycles at 50 percent DOD. The advances made in the Li/TiS2 technology at JPL since 1989 are summarized.

  8. Hematopoietic Stem-Cell Transplantation for Advanced Systemic Mastocytosis

    PubMed Central

    Ustun, Celalettin; Reiter, Andreas; Scott, Bart L.; Nakamura, Ryotaro; Damaj, Gandhi; Kreil, Sebastian; Shanley, Ryan; Hogan, William J.; Perales, Miguel-Angel; Shore, Tsiporah; Baurmann, Herrad; Stuart, Robert; Gruhn, Bernd; Doubek, Michael; Hsu, Jack W.; Tholouli, Eleni; Gromke, Tanja; Godley, Lucy A.; Pagano, Livio; Gilman, Andrew; Wagner, Eva Maria; Shwayder, Tor; Bornhäuser, Martin; Papadopoulos, Esperanza B.; Böhm, Alexandra; Vercellotti, Gregory; Van Lint, Maria Teresa; Schmid, Christoph; Rabitsch, Werner; Pullarkat, Vinod; Legrand, Faezeh; Yakoub-agha, Ibrahim; Saber, Wael; Barrett, John; Hermine, Olivier; Hagglund, Hans; Sperr, Wolfgang R.; Popat, Uday; Alyea, Edwin P.; Devine, Steven; Deeg, H. Joachim; Weisdorf, Daniel; Akin, Cem; Valent, Peter

    2014-01-01

    Purpose Advanced systemic mastocytosis (SM), a fatal hematopoietic malignancy characterized by drug resistance, has no standard therapy. The effectiveness of allogeneic hematopoietic stem-cell transplantation (alloHCT) in SM remains unknown. Patients and Methods In a global effort to define the value of HCT in SM, 57 patients with the following subtypes of SM were evaluated: SM associated with clonal hematologic non–mast cell disorders (SM-AHNMD; n = 38), mast cell leukemia (MCL; n = 12), and aggressive SM (ASM; n = 7). Median age of patients was 46 years (range, 11 to 67 years). Donors were HLA-identical (n = 34), unrelated (n = 17), umbilical cord blood (n = 2), HLA-haploidentical (n = 1), or unknown (n = 3). Thirty-six patients received myeloablative conditioning (MAC), and 21 patients received reduced-intensity conditioning (RIC). Results Responses in SM were observed in 40 patients (70%), with complete remission in 16 patients (28%). Twelve patients (21%) had stable disease, and five patients (9%) had primary refractory disease. Overall survival (OS) at 3 years was 57% for all patients, 74% for patients with SM-AHNMD, 43% for those with ASM, and 17% for those with MCL. The strongest risk factor for poor OS was MCL. Survival was also lower in patients receiving RIC compared with MAC and in patients having progression compared with patients having stable disease or response. Conclusion AlloHCT was associated with long-term survival in patients with advanced SM. Although alloHCT may be considered as a viable and potentially curative therapeutic option for advanced SM in the meantime, given that this is a retrospective analysis with no control group, the definitive role of alloHCT will need to be determined by a prospective trial. PMID:25154823

  9. Monte Carlo simulation of a Bonner sphere spectrometer for application to the determination of neutron field in the Experimental Advanced Superconducting Tokamak experimental hall

    SciTech Connect

    Hu, Z. M.; Xie, X. F.; Chen, Z. J.; Peng, X. Y.; Du, T. F.; Cui, Z. Q.; Ge, L. J.; Li, T.; Yuan, X.; Zhang, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.; Gorini, G.

    2014-11-15

    To assess the neutron energy spectra and the neutron dose for different positions around the Experimental Advanced Superconducting Tokamak (EAST) device, a Bonner Sphere Spectrometer (BSS) was developed at Peking University, with totally nine polyethylene spheres and a SP9 {sup 3}He counter. The response functions of the BSS were calculated by the Monte Carlo codes MCNP and GEANT4 with dedicated models, and good agreement was found between these two codes. A feasibility study was carried out with a simulated neutron energy spectrum around EAST, and the simulated “experimental” result of each sphere was obtained by calculating the response with MCNP, which used the simulated neutron energy spectrum as the input spectrum. With the deconvolution of the “experimental” measurement, the neutron energy spectrum was retrieved and compared with the preset one. Good consistence was found which offers confidence for the application of the BSS system for dose and spectrum measurements around a fusion device.

  10. Monte Carlo simulation of a Bonner sphere spectrometer for application to the determination of neutron field in the Experimental Advanced Superconducting Tokamak experimental hall.

    PubMed

    Hu, Z M; Xie, X F; Chen, Z J; Peng, X Y; Du, T F; Cui, Z Q; Ge, L J; Li, T; Yuan, X; Zhang, X; Hu, L Q; Zhong, G Q; Lin, S Y; Wan, B N; Gorini, G; Li, X Q; Zhang, G H; Chen, J X; Fan, T S

    2014-11-01

    To assess the neutron energy spectra and the neutron dose for different positions around the Experimental Advanced Superconducting Tokamak (EAST) device, a Bonner Sphere Spectrometer (BSS) was developed at Peking University, with totally nine polyethylene spheres and a SP9 (3)He counter. The response functions of the BSS were calculated by the Monte Carlo codes MCNP and GEANT4 with dedicated models, and good agreement was found between these two codes. A feasibility study was carried out with a simulated neutron energy spectrum around EAST, and the simulated "experimental" result of each sphere was obtained by calculating the response with MCNP, which used the simulated neutron energy spectrum as the input spectrum. With the deconvolution of the "experimental" measurement, the neutron energy spectrum was retrieved and compared with the preset one. Good consistence was found which offers confidence for the application of the BSS system for dose and spectrum measurements around a fusion device.

  11. Nonlocal anomalous Hall effect

    NASA Astrophysics Data System (ADS)

    Zhang, Shulei; Vignale, Giovanni

    Anomalous Hall effect (AHE) is a distinctive transport property of ferromagnetic metals arising from spin orbit coupling (SOC) in concert with spontaneous spin polarization. Nonetheless, recent experiments have shown that the effect also appears in a nonmagnetic metal in contact with a magnetic insulator. The main puzzle lies in the apparent absence of spin polarized electrons in the non-magnetic metal. Here, we theoretically demonstrate that the scattering of electrons from a rough metal-insulator interface is generally spin-dependent, which results in mutual conversion between spin and charge currents flowing in the plane of the layer. It is the current-carrying spin polarized electrons and the spin Hall effect in the bulk of the metal layer that conspire to generate the AH current. This novel AHE differs from the conventional one only in the spatial separation of the SOC and the magnetization, so we name it as nonlocal AHE. In contrast to other previously proposed mechanisms (e.g., spin Hall AHE and magnetic proximity effect (MPE)), the nonlocal AHE appears on the first order of spin Hall angle and does not rely on the induced moments in the metal layer, which make it experimentally detectable by contrasting the AH current directions of two layered structures such as Pt/Cu/YIG and β -Ta/Cu/YIG (with a thin inserted Cu layer to eliminate the MPE). We predict that the directions of the AH currents in these two trilayers would be opposite since the spin Hall angles of Pt and β -Ta are of opposite signs. Work supported by NSF Grants DMR-1406568.

  12. Chemotherapy advances in small-cell lung cancer

    PubMed Central

    Chan, Bryan A.

    2013-01-01

    Although chemotherapeutic advances have recently been heralded in lung adenocarcinomas, such success with small-cell lung cancer (SCLC) has been ominously absent. Indeed, the dismal outlook of this disease is exemplified by the failure of any significant advances in first line therapy since the introduction of the current standard platinum-etoposide doublet over 30 years ago. Moreover, such sluggish progress is compounded by the dearth of FDA-approved agents for patients with relapsed disease. However, over the past decade, novel formulations of drug classes commonly used in SCLC (e.g. topoisomerase inhibitors, anthracyclines, alkylating and platinum agents) are emerging as potential alternatives that could effectively add to the armamentarium of agents currently at our disposal. This review is introduced with an overview on the historical development of chemotherapeutic regimens used in this disease and followed by the recent encouraging advances witnessed in clinical trials with drugs such as amrubicin and belotecan which are forging new horizons for future treatment algorithms. PMID:24163749

  13. NASA's 2004 Hall Thruster Program

    NASA Technical Reports Server (NTRS)

    Jacobson, David T.; Manzella, David H.; Hofer, Richard R.; Peterson, Peter Y.

    2004-01-01

    An overview of NASA's Hall thruster research and development tasks conducted during fiscal year 2004 is presented. These tasks focus on: raising the technology readiness level of high power Hall thrusters, developing a moderate-power/ moderate specific impulse Hall thruster, demonstrating high-power/high specific impulse Hall thruster operation, and addressing the fundamental technical challenges of emerging Hall thruster concepts. Programmatic background information, technical accomplishments and out year plans for each program element performed under the sponsorship of the In-Space Transportation Program, Project Prometheus, and the Energetics Project are provided.

  14. Advances in the management of basal cell carcinoma

    PubMed Central

    Carucci, John A.

    2015-01-01

    Basal cell carcinoma (BCC), a malignant neoplasm derived from non-keratinizing cells that originate in the basal layer of the epidermis, is the most common cancer in humans. Several factors such as anatomic location, histologic features, primary or recurrent tumors, and patient characteristics influence the choice of treatment modality for BCC. Mohs micrographic surgery (MMS) facilitates optimal margin control and conservation of normal tissue for the management of BCC; however, other treatment modalities may also be implemented in the correct clinical scenario. Other treatment modalities that will be reviewed include simple excision, electrodesiccation and curettage, cryotherapy, topical immunotherapy and chemotherapy, photodynamic therapy, and radiation therapy. In addition, targeted molecular therapeutic options for the treatment of advanced or metastatic BCC will be discussed in this informal review based on recent literature obtained by using PubMed with relevant search terms. PMID:26097726

  15. Prospects for advanced coal-fuelled fuel cell power plants

    NASA Astrophysics Data System (ADS)

    Jansen, D.; Vanderlaag, P. C.; Oudhuis, A. B. J.; Ribberink, J. S.

    1994-04-01

    As part of ECN's in-house R&D programs on clean energy conversion systems with high efficiencies and low emissions, system assessment studies have been carried out on coal gasification power plants integrated with high-temperature fuel cells (IGFC). The studies also included the potential to reduce CO2 emissions, and to find possible ways for CO2 extraction and sequestration. The development of this new type of clean coal technology for large-scale power generation is still far off. A significant market share is not envisaged before the year 2015. To assess the future market potential of coal-fueled fuel cell power plants, the promise of this fuel cell technology was assessed against the performance and the development of current state-of-the-art large-scale power generation systems, namely the pulverized coal-fired power plants and the integrated coal gasification combined cycle (IGCC) power plants. With the anticipated progress in gas turbine and gas clean-up technology, coal-fueled fuel cell power plants will have to face severe competition from advanced IGCC power plants, despite their higher efficiency.

  16. 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.

  17. Spin Hall effects

    NASA Astrophysics Data System (ADS)

    Sinova, Jairo; Valenzuela, Sergio O.; Wunderlich, J.; Back, C. H.; Jungwirth, T.

    2015-10-01

    Spin Hall effects are a collection of relativistic spin-orbit coupling phenomena in which electrical currents can generate transverse spin currents and vice versa. Despite being observed only a decade ago, these effects are already ubiquitous within spintronics, as standard spin-current generators and detectors. Here the theoretical and experimental results that have established this subfield of spintronics are reviewed. The focus is on the results that have converged to give us the current understanding of the phenomena, which has evolved from a qualitative to a more quantitative measurement of spin currents and their associated spin accumulation. Within the experimental framework, optical-, transport-, and magnetization-dynamics-based measurements are reviewed and linked to both phenomenological and microscopic theories of the effect. Within the theoretical framework, the basic mechanisms in both the extrinsic and intrinsic regimes are reviewed, which are linked to the mechanisms present in their closely related phenomenon in ferromagnets, the anomalous Hall effect. Also reviewed is the connection to the phenomenological treatment based on spin-diffusion equations applicable to certain regimes, as well as the spin-pumping theory of spin generation used in many measurements of the spin Hall angle. A further connection to the spin-current-generating spin Hall effect to the inverse spin galvanic effect is given, in which an electrical current induces a nonequilibrium spin polarization. This effect often accompanies the spin Hall effect since they share common microscopic origins. Both can exhibit the same symmetries when present in structures comprising ferromagnetic and nonmagnetic layers through their induced current-driven spin torques or induced voltages. Although a short chronological overview of the evolution of the spin Hall effect field and the resolution of some early controversies is given, the main body of this review is structured from a pedagogical

  18. Shockley-Read-Hall recombination in P3HT:PCBM solar cells as observed under ultralow light intensities

    SciTech Connect

    Tzabari, Lior; Tessler, Nir

    2011-03-15

    We present light intensity dependent measurements of the quantum efficiency of P3HT:PCBM photovoltaic devices. Unlike previous studies we focus on ultralow light intensities down to 10{sup -3} mW/cm{sup 2}. We find that although when the devices are excited at intensities close to 1 Sun they exhibit very little bias or light intensity dependence, this is clearly not the case for light intensities below 1 mW/cm{sup 2}, where the cell's efficiency becomes highly dependent on the bias and light intensity. Using a simple model for the device efficiency we can fit the experimental data across a wide range of parameters and thus separate the effects of generation efficiency (geminate recombination) and charge recombination. Our finding suggests that recombination through trap (charge transfer) states is an important loss mechanism and we are able to quantify the density and depth of these states.

  19. Recent Stem Cell Advances: Cord Blood and Induced Pluripotent Stem Cell for Cardiac Regeneration- a Review.

    PubMed

    Medhekar, Sheetal Kashinath; Shende, Vikas Suresh; Chincholkar, Anjali Baburao

    2016-05-30

    Stem cells are primitive self renewing undifferentiated cell that can be differentiated into various types of specialized cells like nerve cell, skin cells, muscle cells, intestinal tissue, and blood cells. Stem cells live in bone marrow where they divide to make new blood cells and produces peripheral stem cells in circulation. Under proper environment and in presence of signaling molecules stem cells begin to develop into specialized tissues and organs. These unique characteristics make them very promising entities for regeneration of damaged tissue. Day by day increase in incidence of heart diseases including left ventricular dysfunction, ischemic heart disease (IHD), congestive heart failure (CHF) are the major cause of morbidity and mortality. However infracted tissue cannot regenerate into healthy tissue. Heart transplantation is only the treatment for such patient. Due to limitation of availability of donor for organ transplantation, a focus is made for alternative and effective therapy to treat such condition. In this review we have discussed the new advances in stem cells such as use of cord stem cells and iPSC technology in cardiac repair. Future approach of CB cells was found to be used in tissue repair which is specifically observed for improvement of left ventricular function and myocardial infarction. Here we have also focused on how iPSC technology is used for regeneration of cardiomyocytes and intiating neovascularization in myocardial infarction and also for study of pathophysiology of various degenerative diseases and genetic disease in research field.

  20. Recent Stem Cell Advances: Cord Blood and Induced Pluripotent Stem Cell for Cardiac Regeneration- a Review

    PubMed Central

    Medhekar, Sheetal Kashinath; Shende, Vikas Suresh; Chincholkar, Anjali Baburao

    2016-01-01

    Stem cells are primitive self renewing undifferentiated cell that can be differentiated into various types of specialized cells like nerve cell, skin cells, muscle cells, intestinal tissue, and blood cells. Stem cells live in bone marrow where they divide to make new blood cells and produces peripheral stem cells in circulation. Under proper environment and in presence of signaling molecules stem cells begin to develop into specialized tissues and organs. These unique characteristics make them very promising entities for regeneration of damaged tissue. Day by day increase in incidence of heart diseases including left ventricular dysfunction, ischemic heart disease (IHD), congestive heart failure (CHF) are the major cause of morbidity and mortality. However infracted tissue cannot regenerate into healthy tissue. Heart transplantation is only the treatment for such patient. Due to limitation of availability of donor for organ transplantation, a focus is made for alternative and effective therapy to treat such condition. In this review we have discussed the new advances in stem cells such as use of cord stem cells and iPSC technology in cardiac repair. Future approach of CB cells was found to be used in tissue repair which is specifically observed for improvement of left ventricular function and myocardial infarction. Here we have also focused on how iPSC technology is used for regeneration of cardiomyocytes and intiating neovascularization in myocardial infarction and also for study of pathophysiology of various degenerative diseases and genetic disease in research field. PMID:27426082

  1. Generation of skeletal muscle cells from pluripotent stem cells: advances and challenges.

    PubMed

    Abujarour, Ramzey; Valamehr, Bahram

    2015-01-01

    Human pluripotent stem cells (hPSCs) possess unlimited proliferative potential while maintaining the ability to differentiate into any cell type including skeletal muscle cells (SMCs). hPSCs are amenable to genetic editing and can be derived from patient somatic cells, and thus represent a promising option for cell therapies for the treatment of degenerative diseases such as muscular dystrophies. There are unresolved challenges however associated with the derivation and scale-up of hPSCs and generation of differentiated cells in large quantity and high purity. Reported myogenic differentiation protocols are long, require cell sorting and/or rely on ectopic expression of myogenic master regulators. More recent advances have been made with the application of small molecules to enhance the myogenic differentiation efficiency and the identification of more selective markers for the enrichment of myogenic progenitors with enhanced regenerative potential. Here we review the field of myogenic differentiation and highlight areas requiring further research.

  2. Cylindrical geometry hall thruster

    DOEpatents

    Raitses, Yevgeny; Fisch, Nathaniel J.

    2002-01-01

    An apparatus and method for thrusting plasma, utilizing a Hall thruster with a cylindrical geometry, wherein ions are accelerated in substantially the axial direction. The apparatus is suitable for operation at low power. It employs small size thruster components, including a ceramic channel, with the center pole piece of the conventional annular design thruster eliminated or greatly reduced. Efficient operation is accomplished through magnetic fields with a substantial radial component. The propellant gas is ionized at an optimal location in the thruster. A further improvement is accomplished by segmented electrodes, which produce localized voltage drops within the thruster at optimally prescribed locations. The apparatus differs from a conventional Hall thruster, which has an annular geometry, not well suited to scaling to small size, because the small size for an annular design has a great deal of surface area relative to the volume.

  3. Metallic Wall Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Goebel, Dan Michael (Inventor); Hofer, Richard Robert (Inventor); Mikellides, Ioannis G. (Inventor)

    2016-01-01

    A Hall thruster apparatus having walls constructed from a conductive material, such as graphite, and having magnetic shielding of the walls from the ionized plasma has been demonstrated to operate with nearly the same efficiency as a conventional non-magnetically shielded design using insulators as wall components. The new design is believed to provide the potential of higher power and uniform operation over the operating life of a thruster device.

  4. Development of Nanosized/Nanostructured Silicon as Advanced Anodes for Lithium-Ion Cells

    NASA Technical Reports Server (NTRS)

    Wu, James J.

    2015-01-01

    NASA is developing high energy and high capacity Li-ion cell and battery designs for future exploration missions under the NASA Advanced Space Power System (ASPS) Program. The specific energy goal is 265 Wh/kg at 10 C. center dot Part of effort for NASA advanced Li-ion cells ? Anode: Silicon (Si) as an advanced anode. ? Electrolyte: advanced electrolyte with flame-retardant additives for enhanced performance and safety (NASA JPL).

  5. Advanced tendencies in development of photovoltaic cells for power engineering

    NASA Astrophysics Data System (ADS)

    Strebkov, D. S.

    2015-01-01

    Development of solar power engineering must be based on original innovative Russian and world technologies. It is necessary to develop promising Russian technologies of manufacturing of photovoltaic cells and semiconductor materials: chlorine-free technology for obtaining solar silicon; matrix solar cell technology with an efficiency of 25-30% upon the conversion of concentrated solar, thermal, and laser radiation; encapsulation technology for high-voltage silicon solar modules with a voltage up to 1000 V and a service life up to 50 years; new methods of concentration of solar radiation with the balancing illumination of photovoltaic cells at 50-100-fold concentration; and solar power systems with round-the-clock production of electrical energy that do not require energy storage devices and reserve sources of energy. The advanced tendency in silicon power engineering is the use of high-temperature reactions in heterogeneous modular silicate solutions for long-term (over one year) production of heat and electricity in the autonomous mode.

  6. Advanced fuel cells for transportation applications. Final report

    SciTech Connect

    1998-02-10

    This Research and Development (R and D) contract was directed at developing an advanced technology compressor/expander for supplying compressed air to Proton Exchange Membrane (PEM) fuel cells in transportation applications. The objective of this project was to develop a low-cost high-efficiency long-life lubrication-free integrated compressor/expander utilizing scroll technology. The goal of this compressor/expander was to be capable of providing compressed air over the flow and pressure ranges required for the operation of 50 kW PEM fuel cells in transportation applications. The desired ranges of flow, pressure, and other performance parameters were outlined in a set of guidelines provided by DOE. The project consisted of the design, fabrication, and test of a prototype compressor/expander module. The scroll CEM development program summarized in this report has been very successful, demonstrating that scroll technology is a leading candidate for automotive fuel cell compressor/expanders. The objectives of the program are: develop an integrated scroll CEM; demonstrate efficiency and capacity goals; demonstrate manufacturability and cost goals; and evaluate operating envelope. In summary, while the scroll CEM program did not demonstrate a level of performance as high as the DOE guidelines in all cases, it did meet the overriding objectives of the program. A fully-integrated, low-cost CEM was developed that demonstrated high efficiency and reliable operation throughout the test program. 26 figs., 13 tabs.

  7. Use of advanced solar cells for commercial communication satellites

    NASA Astrophysics Data System (ADS)

    Bailey, Sheila G.; Landis, Geoffrey A.

    1995-03-01

    The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

  8. Use of advanced solar cells for commerical communication satellites

    NASA Astrophysics Data System (ADS)

    Landis, Geoffrey A.; Bailey, Sheila G.

    1995-01-01

    The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar- and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because of the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from Low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

  9. Advanced coal gasifier-fuel cell power plant systems design

    NASA Technical Reports Server (NTRS)

    Heller, M. E.

    1983-01-01

    Two advanced, high efficiency coal-fired power plants were designed, one utilizing a phosphoric acid fuel cell and one utilizing a molten carbonate fuel cell. Both incorporate a TRW Catalytic Hydrogen Process gasifier and regenerator. Both plants operate without an oxygen plant and without requiring water feed; they, instead, require makeup dolomite. Neither plant requires a shift converter; neither plant has heat exchangers operating above 1250 F. Both plants have attractive efficiencies and costs. While the molten carbonate version has a higher (52%) efficiency than the phosphoric acid version (48%), it also has a higher ($0.078/kWh versus $0.072/kWh) ten-year levelized cost of electricity. The phosphoric acid fuel cell power plant is probably feasible to build in the near term: questions about the TRW process need to be answered experimentally, such as weather it can operate on caking coals, and how effective the catalyzed carbon-dioxide acceptor will be at pilot scale, both in removing carbon dioxide and in removing sulfur from the gasifier.

  10. Recent advances in the ITO/InP solar cell

    NASA Technical Reports Server (NTRS)

    Gessert, T. A.; Li, X.; Wanlass, M. W.; Coutts, T. J.

    1991-01-01

    It was demonstrated that Indium Tin Oxide (ITO)/InP solar cells can now be made on as-received p(-) bulk substrates which are of nearly equal quality to those which could previously only be made on epitaxially grown p(-) InP base layers. Although this advancement is due in part to both increases in substrate quality and a better understanding of back contact formation, it appears that the passivation/compensation effects resulting from having H2 in the sputtering gas tends to reduce significantly the performance differences previously observed between these two substrates. It is shown that since high efficiency ITO/InP cells can be made from as-received substrates, and since the type conversion process is not highly spatially dependent, large area ITO/InP cells (4 sq cm) with efficiencies approaching 17 percent (Global) can be made. Furthermore, the measured open circuit voltages (V sub OC) and quantum efficiencies (QEs) from these large cells suggest that, when they are processed using optimum grid designs, the efficiencies will be nearly equal to that of the smaller cells thus far produced. It has been shown, through comparative experiments involving ITO/InP and IO/InP cells, that Sn may not be the major cause of type conversion of the InP surface and thus further implies that the ITO may not be an essential element in this type of device. Specifically, very efficient photovoltaic solar cells were made by sputtering (Sn free) In2O3 showing that type conversion and subsequent junction formation will occur even in the absence of the sputtered SN species. The result suggests that sputter damage may indeed be the important mechanism(s) of type conversion. Finally, an initial study of the stability of the ITO/InP cell done over the course of about one year has indicated that the J(sub SC) (short circuit current) and the fill factor (FF) are measurably stable within experimental certainty.

  11. 27. THIRD FLOOR MAIN HALL FROM SIDE HALL LEADING TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. THIRD FLOOR MAIN HALL FROM SIDE HALL LEADING TO SERVICE STAIRS This hall is lit by three natural sources, the lightwell window of the main stairs visible in the distance, the skylight in the linen closet at the extreme left, and from the glazed openings in the interior and exterior doors of the nurse's room, out of sight to the right. - Woodrow Wilson House, 2340 South S Street, Northwest, Washington, District of Columbia, DC

  12. Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing

    SciTech Connect

    Fletcher, James H.; Cox, Philip; Harrington, William J; Campbell, Joseph L

    2013-09-03

    ABSTRACT Project Title: Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing PROJECT OBJECTIVE The objective of the project was to advance portable fuel cell system technology towards the commercial targets of power density, energy density and lifetime. These targets were laid out in the DOE’s R&D roadmap to develop an advanced direct methanol fuel cell power supply that meets commercial entry requirements. Such a power supply will enable mobile computers to operate non-stop, unplugged from the wall power outlet, by using the high energy density of methanol fuel contained in a replaceable fuel cartridge. Specifically this project focused on balance-of-plant component integration and miniaturization, as well as extensive component, subassembly and integrated system durability and validation testing. This design has resulted in a pre-production power supply design and a prototype that meet the rigorous demands of consumer electronic applications. PROJECT TASKS The proposed work plan was designed to meet the project objectives, which corresponded directly with the objectives outlined in the Funding Opportunity Announcement: To engineer the fuel cell balance-of-plant and packaging to meet the needs of consumer electronic systems, specifically at power levels required for mobile computing. UNF used existing balance-of-plant component technologies developed under its current US Army CERDEC project, as well as a previous DOE project completed by PolyFuel, to further refine them to both miniaturize and integrate their functionality to increase the system power density and energy density. Benefits of UNF’s novel passive water recycling MEA (membrane electrode assembly) and the simplified system architecture it enabled formed the foundation of the design approach. The package design was hardened to address orientation independence, shock, vibration, and environmental requirements. Fuel cartridge and fuel subsystems were improved to ensure effective fuel

  13. Interfacial Materials for Organic Solar Cells: Recent Advances and Perspectives

    PubMed Central

    Yin, Zhigang; Wei, Jiajun

    2016-01-01

    Organic solar cells (OSCs) have shown great promise as low‐cost photovoltaic devices for solar energy conversion over the past decade. Interfacial engineering provides a powerful strategy to enhance efficiency and stability of OSCs. With the rapid advances of interface layer materials and active layer materials, power conversion efficiencies (PCEs) of both single‐junction and tandem OSCs have exceeded a landmark value of 10%. This review summarizes the latest advances in interfacial layers for single‐junction and tandem OSCs. Electron or hole transporting materials, including metal oxides, polymers/small‐molecules, metals and metal salts/complexes, carbon‐based materials, organic‐inorganic hybrids/composites, and other emerging materials, are systemically presented as cathode and anode interface layers for high performance OSCs. Meanwhile, incorporating these electron‐transporting and hole‐transporting layer materials as building blocks, a variety of interconnecting layers for conventional or inverted tandem OSCs are comprehensively discussed, along with their functions to bridge the difference between adjacent subcells. By analyzing the structure–property relationships of various interfacial materials, the important design rules for such materials towards high efficiency and stable OSCs are highlighted. Finally, we present a brief summary as well as some perspectives to help researchers understand the current challenges and opportunities in this emerging area of research. PMID:27812480

  14. Microalgal drying and cell disruption--recent advances.

    PubMed

    Show, Kuan-Yeow; Lee, Duu-Jong; Tay, Joo-Hwa; Lee, Tse-Min; Chang, Jo-Shu

    2015-05-01

    Production of intracellular metabolites or biofuels from algae involves various processing steps, and extensive work on laboratory- and pilot-scale algae cultivation, harvesting and processing has been reported. As algal drying and cell disruption are integral processes of the unit operations, this review examines recent advances in algal drying and disruption for nutrition or biofuel production. Challenges and prospects of the processing are also outlined. Engineering improvements in addressing the challenges of energy efficiency and cost-effective and rigorous techno-economic analyses for a clearer prospect comparison between different processing methods are highlighted. Holistic life cycle assessments need to be conducted in assessing the energy balance and the potential environmental impacts of algal processing. The review aims to provide useful information for future development of efficient and commercially viable algal food products and biofuels production.

  15. Microalgal drying and cell disruption--recent advances.

    PubMed

    Show, Kuan-Yeow; Lee, Duu-Jong; Tay, Joo-Hwa; Lee, Tse-Min; Chang, Jo-Shu

    2015-05-01

    Production of intracellular metabolites or biofuels from algae involves various processing steps, and extensive work on laboratory- and pilot-scale algae cultivation, harvesting and processing has been reported. As algal drying and cell disruption are integral processes of the unit operations, this review examines recent advances in algal drying and disruption for nutrition or biofuel production. Challenges and prospects of the processing are also outlined. Engineering improvements in addressing the challenges of energy efficiency and cost-effective and rigorous techno-economic analyses for a clearer prospect comparison between different processing methods are highlighted. Holistic life cycle assessments need to be conducted in assessing the energy balance and the potential environmental impacts of algal processing. The review aims to provide useful information for future development of efficient and commercially viable algal food products and biofuels production. PMID:25465783

  16. Judy Estes Hall (1940-2015).

    PubMed

    Sammons, Morgan T; Boucher, Andrew

    2016-01-01

    Presents an obituary for Judy Estes Hall, who passed away on November 24, 2015. Hall served as the Executive Officer of the National Register of Health Service Psychologists until her retirement in 2013. She is a recognized expert in the development of education and training standards for the profession of psychology, she also made significant contributions in the field of international psychology, where she was a renowned expert in cross-national credentialing and an advocate for commonality in licensing standards. She was the coauthor of one edited volume and author of more than 60 journal articles, book chapters, and professional publications. A passionate advocate for the advancement of women in psychology, a devoted mother and grandmother, a connoisseur of wine and international traveler extraordinaire, she touched the personal and professional lives of many. (PsycINFO Database Record

  17. Judy Estes Hall (1940-2015).

    PubMed

    Sammons, Morgan T; Boucher, Andrew

    2016-01-01

    Presents an obituary for Judy Estes Hall, who passed away on November 24, 2015. Hall served as the Executive Officer of the National Register of Health Service Psychologists until her retirement in 2013. She is a recognized expert in the development of education and training standards for the profession of psychology, she also made significant contributions in the field of international psychology, where she was a renowned expert in cross-national credentialing and an advocate for commonality in licensing standards. She was the coauthor of one edited volume and author of more than 60 journal articles, book chapters, and professional publications. A passionate advocate for the advancement of women in psychology, a devoted mother and grandmother, a connoisseur of wine and international traveler extraordinaire, she touched the personal and professional lives of many. (PsycINFO Database Record PMID:27504582

  18. Cell death goes LIVE: technological advances in real-time tracking of cell death.

    PubMed

    Skommer, Joanna; Darzynkiewicz, Zbigniew; Wlodkowic, Donald

    2010-06-15

    Cell population can be viewed as a quantum system, which like Schrödinger's cat exists as a combination of survival- and death-allowing states. Tracking and understanding cell-to-cell variability in processes of high spatio-temporal complexity such as cell death is at the core of current systems biology approaches. As probabilistic modeling tools attempt to impute information inaccessible by current experimental approaches, advances in technologies for single-cell imaging and omics (proteomics, genomics, metabolomics) should go hand in hand with the computational efforts. Over the last few years we have made exciting technological advances that allow studies of cell death dynamically in real-time and with the unprecedented accuracy. These approaches are based on innovative fluorescent assays and recombinant proteins, bioelectrical properties of cells, and more recently also on state-of-the-art optical spectroscopy. Here, we review current status of the most innovative analytical technologies for dynamic tracking of cell death, and address the interdisciplinary promises and future challenges of these methods.

  19. Advanced proton-exchange materials for energy efficient fuel cells.

    SciTech Connect

    Fujimoto, Cy H.; Grest, Gary Stephen; Hickner, Michael A.; Cornelius, Christopher James; Staiger, Chad Lynn; Hibbs, Michael R.

    2005-12-01

    The ''Advanced Proton-Exchange Materials for Energy Efficient Fuel Cells'' Laboratory Directed Research and Development (LDRD) project began in October 2002 and ended in September 2005. This LDRD was funded by the Energy Efficiency and Renewable Energy strategic business unit. The purpose of this LDRD was to initiate the fundamental research necessary for the development of a novel proton-exchange membranes (PEM) to overcome the material and performance limitations of the ''state of the art'' Nafion that is used in both hydrogen and methanol fuel cells. An atomistic modeling effort was added to this LDRD in order to establish a frame work between predicted morphology and observed PEM morphology in order to relate it to fuel cell performance. Significant progress was made in the area of PEM material design, development, and demonstration during this LDRD. A fundamental understanding involving the role of the structure of the PEM material as a function of sulfonic acid content, polymer topology, chemical composition, molecular weight, and electrode electrolyte ink development was demonstrated during this LDRD. PEM materials based upon random and block polyimides, polybenzimidazoles, and polyphenylenes were created and evaluated for improvements in proton conductivity, reduced swelling, reduced O{sub 2} and H{sub 2} permeability, and increased thermal stability. Results from this work reveal that the family of polyphenylenes potentially solves several technical challenges associated with obtaining a high temperature PEM membrane. Fuel cell relevant properties such as high proton conductivity (>120 mS/cm), good thermal stability, and mechanical robustness were demonstrated during this LDRD. This report summarizes the technical accomplishments and results of this LDRD.

  20. Hairy cell leukemia: clinical features and therapeutic advances.

    PubMed

    Lembersky, B C; Golomb, H M

    1987-01-01

    Hairy cell leukemia (HCL) is a rare chronic lymphoproliferative disorder which has been extensively studied over the past decade. Much has been learned regarding the diagnosis, natural history, biology, and treatment of this unique neoplasm. The disease most commonly affects middle aged men and characteristic clinical features include splenomegaly, cytopenias, and usually the presence in the peripheral blood of distinctive 'hairy cells' with irregular cytoplasmic projections. Diagnosis can usually be confirmed by bone marrow biopsy. Although the natural history can be extremely variable among patients, complications are usually referable to the cytopenias, with anemia and infection being most frequent. In addition to pyogenic infections, patients are susceptible to unusual organisms including atypical mycobacterium, legionella, and fungi. The requirement of red blood cell transfusion, severe granulocytopenia or thrombocytopenia, frequent infections, or painful splenomegaly are all indications for treatment. Splenectomy is the standard initial treatment of choice. However, in the past few years there have been exciting major advances in the therapeutic modalities for HCL. Recombinant alpha-interferon is highly effective, with beneficial responses occurring in close to 90% of patients. The Food and Drug Administration has recently approved the use of interferon for HCL. This represents the first time a biological response modifier has been approved for the treatment of human disease. In addition, preliminary results with the adenosine deaminase inhibitor, 2'deoxycoformycin (dcf), have been encouraging. Further clinical trials are required in order to determine the optimal sequential treatment strategy for HCL. The exact mechanisms of action of both interferon and dcf in HCL remain to be elucidated. A better understanding of the unusual features of the hairy cell and the underlying biological effect of these two agents in HCL may have important applications in other

  1. Hepatocyte and Sertoli Cell Aquaporins, Recent Advances and Research Trends

    PubMed Central

    Bernardino, Raquel L.; Marinelli, Raul A.; Maggio, Anna; Gena, Patrizia; Cataldo, Ilaria; Alves, Marco G.; Svelto, Maria; Oliveira, Pedro F.; Calamita, Giuseppe

    2016-01-01

    Aquaporins (AQPs) are proteinaceous channels widespread in nature where they allow facilitated permeation of water and uncharged through cellular membranes. AQPs play a number of important roles in both health and disease. This review focuses on the most recent advances and research trends regarding the expression and modulation, as well as physiological and pathophysiological functions of AQPs in hepatocytes and Sertoli cells (SCs). Besides their involvement in bile formation, hepatocyte AQPs are involved in maintaining energy balance acting in hepatic gluconeogenesis and lipid metabolism, and in critical processes such as ammonia detoxification and mitochondrial output of hydrogen peroxide. Roles are played in clinical disorders including fatty liver disease, diabetes, obesity, cholestasis, hepatic cirrhosis and hepatocarcinoma. In the seminiferous tubules, particularly in SCs, AQPs are also widely expressed and seem to be implicated in the various stages of spermatogenesis. Like in hepatocytes, AQPs may be involved in maintaining energy homeostasis in these cells and have a major role in the metabolic cooperation established in the testicular tissue. Altogether, this information represents the mainstay of current and future investigation in an expanding field. PMID:27409609

  2. Hematopoietic cell transplantation for hemophagocytic lymphohistiocytosis: recent advances and controversies.

    PubMed

    Seo, Jong Jin

    2015-09-01

    Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory clinical syndrome of uncontrolled immune response which results in hypercytokinemia due to underlying primary or secondary immune defect. A number of genetic defects in transport, processing and function of cytotoxic granules which result in defective granule exocytosis and cytotoxicity of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells have been well identified at the cellular and molecular level. Important advances have been made during the last 20 years in the diagnosis and treatment of HLH. The Histiocyte Society has proposed diagnostic guideline using both clinical and laboratory findings in HLH-2004 protocol, and this has been modified partly in 2009. HLH used to be a fatal disease, but the survival of HLH patients has improved to more than 60% with the use of chemoimmunotherapy combined with hematopoietic cell transplantation (HCT) over the past 2 decades. However, HCT is still the only curative option of treatment for primary HLH and refractory/relapsed HLH after proper chemoimmunotherapy. The outcome of HCT for HLH patients was also improved steadily during last decades, but HCT for HLH still carries significant mortality and morbidity. Moreover, there remain ongoing controversies in various aspects of HCT including indication of HCT, donor selection, timing of HCT, conditioning regimen, and mixed chimerism after HCT. This review summarized the important practical issues which were proven by previous studies on HCT for HLH, and tried to delineate the controversies among them.

  3. Transcatheter embolization of advanced renal cell carcinoma with radioactive seeds

    SciTech Connect

    Lang, E.K.; deKernion, J.B.

    1981-11-01

    Advanced renal cell carcinoma was treated by transcatheter embolization with radioactive seeds. There were 14 patients with nonresectable or metastatic disease (stage IV) and 8 with stage II tumors treated. In 8 patients the tumor was implanted with radon seeds, complemented by 2,500 rad of external beam therapy, and 10 were treated by embolization with 125iodine seeds. The total dose delivered ranged form 1,600 to 14,000 rad. Several patients also had intra-arterial chemotherapy. Survival was improved over previously reported studies: 13 of 22 (59 per cent) at risk for 2 years and 5 of 15 (33 per cent) for 5 years. Distant metastases did not resolve but significant local palliation was achieved. Tumor size decreased in all patients, 8 of whom subsequently underwent nephrectomy. Other local effects included pain control (10 per cent), weight gain (75 per cent) and control of hemorrhage (88 per cent). Toxicity was minimal and consisted of mild nausea or pain. This approach, using a low energy emitter, allows selective high dose radiation of the tumor, while sparing the adjacent normal tissues. In contrast to renal artery occlusion with inert embolic material, subsequent nephrectomy in patients with disseminated disease is not necessary. Transcatheter embolization with radioactive seeds should be considered a reasonable palliative procedure in patients with nonresectable primary renal cell carcinoma.

  4. Magnesium Hall Thruster

    NASA Technical Reports Server (NTRS)

    Szabo, James J.

    2015-01-01

    This Phase II project is developing a magnesium (Mg) Hall effect thruster system that would open the door for in situ resource utilization (ISRU)-based solar system exploration. Magnesium is light and easy to ionize. For a Mars- Earth transfer, the propellant mass savings with respect to a xenon Hall effect thruster (HET) system are enormous. Magnesium also can be combusted in a rocket with carbon dioxide (CO2) or water (H2O), enabling a multimode propulsion system with propellant sharing and ISRU. In the near term, CO2 and H2O would be collected in situ on Mars or the moon. In the far term, Mg itself would be collected from Martian and lunar regolith. In Phase I, an integrated, medium-power (1- to 3-kW) Mg HET system was developed and tested. Controlled, steady operation at constant voltage and power was demonstrated. Preliminary measurements indicate a specific impulse (Isp) greater than 4,000 s was achieved at a discharge potential of 400 V. The feasibility of delivering fluidized Mg powder to a medium- or high-power thruster also was demonstrated. Phase II of the project evaluated the performance of an integrated, highpower Mg Hall thruster system in a relevant space environment. Researchers improved the medium power thruster system and characterized it in detail. Researchers also designed and built a high-power (8- to 20-kW) Mg HET. A fluidized powder feed system supporting the high-power thruster was built and delivered to Busek Company, Inc.

  5. Invited review: Stem cells and muscle diseases: advances in cell therapy strategies.

    PubMed

    Negroni, Elisa; Gidaro, Teresa; Bigot, Anne; Butler-Browne, Gillian S; Mouly, Vincent; Trollet, Capucine

    2015-04-01

    Despite considerable progress to increase our understanding of muscle genetics, pathophysiology, molecular and cellular partners involved in muscular dystrophies and muscle ageing, there is still a crucial need for effective treatments to counteract muscle degeneration and muscle wasting in such conditions. This review focuses on cell-based therapy for muscle diseases. We give an overview of the different parameters that have to be taken into account in such a therapeutic strategy, including the influence of muscle ageing, cell proliferation and migration capacities, as well as the translation of preclinical results in rodent into human clinical approaches. We describe recent advances in different types of human myogenic stem cells, with a particular emphasis on myoblasts but also on other candidate cells described so far [CD133+ cells, aldehyde dehydrogenase-positive cells (ALDH+), muscle-derived stem cells (MuStem), embryonic stem cells (ES) and induced pluripotent stem cells (iPS)]. Finally, we provide an update of ongoing clinical trials using cell therapy strategies.

  6. Technological Advancements

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2010-01-01

    The influx of technology has brought significant improvements to school facilities. Many of those advancements can be found in classrooms, but when students head down the hall to use the washrooms, they are likely to find a host of technological innovations that have improved conditions in that part of the building. This article describes modern…

  7. Quantum Hall Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Radzihovsky, Leo

    2003-03-01

    Liquid-crystals, defined as states of matter intermediate in their properties between fully disordered isotropic liquids and fully ordered crystals are ubiquitous in nature. Recent transport measurements on two-dimensional electron systems in moderate magnetic fields suggest the existence of a spontaneously orientationally-ordered, compressible liquid state. I will discuss electronic liquid-crystals interpretation of these experiments, focusing on a recently proposed quantum Hall nematic state that is predicted to exhibit a novel, highly anisotropic q^3 density-director mode and other interesting phenomenology.

  8. Predictors of Residence Hall Involvement

    ERIC Educational Resources Information Center

    Arboleda, Ana; Wang, Yongyi; Shelley, Mack C., II; Whalen, Donald F.

    2003-01-01

    Residence hall students' (N = 1,186, 52% male, 90% White, 66% freshmen) involvement in their living community is influenced significantly by precollege student characteristics (gender, ethnicity), classification, attitudes (toward hall director, house cabinet, academic comfort, social environment, group study), and environmental variables (noise,…

  9. Residence Hall Seating That Works.

    ERIC Educational Resources Information Center

    Wiens, Janet

    2003-01-01

    Describes the seating chosen for residence halls at the Massachusetts Institute of Technology and the University of New England. The seating required depends on ergonomics, aesthetics, durability, cost, and code requirements. In addition, residence halls must have a range of seating types to accommodate various uses. (SLD)

  10. Response to Stolley and Hall.

    ERIC Educational Resources Information Center

    Strong, Bryan; DeVault, Christine

    1994-01-01

    Responds to previous article by Stolley and Hall (this issue) on presentation of abortion and adoption in undergraduate marriage and family textbooks. Agrees that adoption should be covered more comprehensively, but disagrees with Stolley and Hall on issue of parity of coverage of adoption and abortion as choices in resolution of unwanted…

  11. Initial Comparisons between the Advanced Technology Development Gen 2 Baseline Cells and Variant C Cells

    SciTech Connect

    Christophersen, Jon Petter; Motloch, Chester George; Wright, Randy Ben; Murphy, Timothy Collins; Belt, Jeffrey R; Ho, Chinh Dac; Bloom, Ira D.; Jones, S. A.; Battaglia, Vincent S.; Jungst, Rudy G.; Case, Herb L.; Sutula, Raymond A.; Barnes, James A.; Duong, Tien Q.

    2002-06-01

    The Advanced Technology Development Program is testing a second generation of lithium-ion cells, consisting of a baseline and three variant chemistries. The cathode composition of the Variant C chemistry was altered with an increase to the aluminum dopant and a decrease to the cobalt dopant to explore the impact on performance. However, it resulted in a 20% drop in rated capacity. Also, the Variant C average power fade is higher, but capacity fade is higher for the Baseline cell chemistry. Initial results indicate that the Variant C chemistry will reach end of life sooner than the Baseline chemistry.

  12. NASA's Hall Thruster Program 2002

    NASA Technical Reports Server (NTRS)

    Jankovsky, Robert S.; Jacobson, David T.; Pinero, Luis R.; Manzella, David H.; Hofer, Richard R.; Peterson, Peter Y.

    2002-01-01

    The NASA Hall thruster program currently supports a number of tasks related to high power thruster development for a number of customers including the Energetics Program (formerly called the Space-based Program), the Space Solar Power Program, and the In-space Propulsion Program. In program year 2002, two tasks were central to the NASA Hall thruster program: 1) the development of a laboratory Hall thruster capable of providing high thrust at high power-, and 2) investigations into operation of Hall thrusters at high specific impulse. In addition to these two primary thruster development activities, there are a number of other on-going activities supported by the NASA Hall thruster program. These additional activities are related to issues such as high-power power processor architecture, thruster lifetime, and spacecraft integration.

  13. Advanced Nanomaterials for High-Efficiency Solar Cells

    SciTech Connect

    Chen, Junhong

    2013-11-29

    Energy supply has arguably become one of the most important problems facing humankind. The exponential demand for energy is evidenced by dwindling fossil fuel supplies and record-high oil and gas prices due to global population growth and economic development. This energy shortage has significant implications to the future of our society, in addition to the greenhouse gas emission burden due to consumption of fossil fuels. Solar energy seems to be the most viable choice to meet our clean energy demand given its large scale and clean/renewable nature. However, existing methods to convert sun light into electricity are not efficient enough to become a practical alternative to fossil fuels. This DOE project aims to develop advanced hybrid nanomaterials consisting of semiconductor nanoparticles (quantum dots or QDs) supported on graphene for cost-effective solar cells with improved conversion efficiency for harvesting abundant, renewable, clean solar energy to relieve our global energy challenge. Expected outcomes of the project include new methods for low-cost manufacturing of hybrid nanostructures, systematic understanding of their properties that can be tailored for desired applications, and novel photovoltaic cells. Through this project, we have successfully synthesized a number of novel nanomaterials, including vertically-oriented graphene (VG) sheets, three-dimensional (3D) carbon nanostructures comprising few-layer graphene (FLG) sheets inherently connected with CNTs through sp{sup 2} carbons, crumpled graphene (CG)-nanocrystal hybrids, CdSe nanoparticles (NPs), CdS NPs, nanohybrids of metal nitride decorated on nitrogen-doped graphene (NG), QD-carbon nanotube (CNT) and QD-VG-CNT structures, TiO{sub 2}-CdS NPs, and reduced graphene oxide (RGO)-SnO{sub 2} NPs. We further assembled CdSe NPs onto graphene sheets and investigated physical and electronic interactions between CdSe NPs and the graphene. Finally we have demonstrated various applications of these

  14. Diagnostics Systems for Permanent Hall Thrusters Development

    NASA Astrophysics Data System (ADS)

    Ferreira, Jose Leonardo; Soares Ferreira, Ivan; Santos, Jean; Miranda, Rodrigo; Possa, M. Gabriela

    -Effect Thruster (PMHET), developed at the Plasma Physics Laboratory of UnB. The idea of using an array of permanent magnets, instead of an electromagnet, to produce a radial magnetic field inside the cylindrical plasma drift channel of the thruster is very attractive, especially because of the possibility of developing a HET with power consumption low enough to be used in small satellites or medium-size satellites with low on board power. Hall-Effect Thrusters are now a very good option for spacecraft primary propulsion and also for station-keeping of medium and large satellites. This is because of their high specific impulse, efficient use of propellant mass and combined low and precise thrust capabilities, which are related to an economy in terms of propellant mass utilization , longer satellite lifetime and easier spacecraft maneuvering in microgravity environment. The first HETs were developed in the mid 1950’s, and they were first called Closed Drift Thrusters. Today, the successful use of electric thrusters for attitude control and orbit modification on hundreds of satellites shows the advanced stage of development of this technology. In addition to this, after the success of space missions such as Deep Space One and Dawn (NASA), Hayabusa (JAXA) and Smart-1 (ESA), the employment of electric thrusters is also consolidated for the primary propulsion of spacecraft. This success is mainly due to three factors: reliability of this technology; efficiency of propellant utilization, and therefore reduction of the initial mass of the ship; possibility of operation over long time intervals, with practically unlimited cycling and restarts. This thrusting system is designed to be used in satellite attitude control and long term space missions. One of the greatest advantage of this kind of thruster is the production of a steady state magnetic field by permanent magnets providing electron trapping and Hall current generation within a significant decrease on the electric energy supply

  15. Recent advances and future applications of microfluidic live-cell microarrays.

    PubMed

    Rothbauer, Mario; Wartmann, David; Charwat, Verena; Ertl, Peter

    2015-11-01

    Microfluidic live-cell microarrays show much promise as screening tools for biomedical research because they could shed light on key biological processes such as cell signaling and cell-to-cell and cell-to-substrate dynamic responses. While miniaturization reduces the need for expensive clinical grade reagents, the integration of functional components including micropumps, biosensors, actuators, mixers and gradient generators results in improved assay reliability, reproducibility and well-defined cell culture conditions. The present review addresses recent technological advances in microfluidic live-cell microarray technology with a special focus on the applications of microfluidic single-cell, multi-cell and 3D cell microarrays.

  16. Farm Hall: The Play

    NASA Astrophysics Data System (ADS)

    Cassidy, David C.

    2013-03-01

    It's July 1945. Germany is in defeat and the atomic bombs are on their way to Japan. Under the direction of Samuel Goudsmit, the Allies are holding some of the top German nuclear scientists-among them Heisenberg, Hahn, and Gerlach-captive in Farm Hall, an English country manor near Cambridge, England. As secret microphones record their conversations, the scientists are unaware of why they are being held or for how long. Thinking themselves far ahead of the Allies, how will they react to the news of the atomic bombs? How will these famous scientists explain to themselves and to the world their failure to achieve even a chain reaction? How will they come to terms with the horror of the Third Reich, their work for such a regime, and their behavior during that period? This one-act play is based upon the transcripts of their conversations as well as the author's historical work on the subject.

  17. Hall Effect Gyrators and Circulators

    NASA Astrophysics Data System (ADS)

    Viola, Giovanni; DiVincenzo, David P.

    2014-04-01

    The electronic circulator and its close relative the gyrator are invaluable tools for noise management and signal routing in the current generation of low-temperature microwave systems for the implementation of new quantum technologies. The current implementation of these devices using the Faraday effect is satisfactory but requires a bulky structure whose physical dimension is close to the microwave wavelength employed. The Hall effect is an alternative nonreciprocal effect that can also be used to produce desired device functionality. We review earlier efforts to use an Ohmically contacted four-terminal Hall bar, explaining why this approach leads to unacceptably high device loss. We find that capacitive coupling to such a Hall conductor has much greater promise for achieving good circulator and gyrator functionality. We formulate a classical Ohm-Hall analysis for calculating the properties of such a device, and show how this classical theory simplifies remarkably in the limiting case of the Hall angle approaching 90°. In this limit, we find that either a four-terminal or a three-terminal capacitive device can give excellent circulator behavior, with device dimensions far smaller than the ac wavelength. An experiment is proposed to achieve GHz-band gyration in millimeter (and smaller) scale structures employing either semiconductor heterostructure or graphene Hall conductors. An inductively coupled scheme for realizing a Hall gyrator is also analyzed.

  18. Effect of NASA advanced designs on thermal behavior of Ni-H2 cells

    NASA Technical Reports Server (NTRS)

    Gonzalez-Sanabria, Olga D.

    1987-01-01

    As part of an overall effort to advance the technology of nickel-hydrogen batteries for low Earth orbit (LEO) applications, advanced designs for individual pressure vessel (IPV) nickel-hydrogen cells have been conceived. These designs incorporate alternative methods of oxygen recombination which affect the thermal behavior of the cells. The effect of these oxygen recombination methods on the cell temperature profiles is examined.

  19. Tuning giant anomalous Hall resistance ratio in perpendicular Hall balance

    SciTech Connect

    Zhang, J. Y.; Yang, G.; Wang, S. G. E-mail: ghyu@mater.ustb.edu.cn; Liu, J. L.; Wang, R. M.; Amsellem, E.; Kohn, A.; Yu, G. H. E-mail: ghyu@mater.ustb.edu.cn

    2015-04-13

    Anomalous Hall effect at room temperature in perpendicular Hall balance with a core structure of [Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4} has been tuned by functional CoO layers, where [Pt/Co]{sub 4} multilayers exhibit perpendicular magnetic anisotropy. A giant Hall resistance ratio up to 69 900% and saturation Hall resistance (R{sub S}{sup P}) up to 2590 mΩ were obtained in CoO/[Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4}/CoO system, which is 302% and 146% larger than that in the structure without CoO layers, respectively. Transmission electron microscopy shows highly textured [Co/Pt]{sub 4} multilayers and oxide layers with local epitaxial relations, indicating that the crystallographic structure has significant influence on spin dependent transport properties.

  20. Nanoconstriction-based spin-Hall nano-oscillator

    SciTech Connect

    Demidov, V. E.; Urazhdin, S.; Zholud, A.; Sadovnikov, A. V.; Demokritov, S. O.

    2014-10-27

    We experimentally demonstrate magnetic nano-oscillators driven by pure spin current produced by the spin Hall effect in a bow tie-shaped nanoconstriction. These devices exhibit single-mode auto-oscillation and generate highly-coherent electronic microwave signals with a significant power and the spectral linewidth as low as 6.2 MHz at room temperature. The proposed simple and flexible device geometry is amenable to straightforward implementation of advanced spintronic structures such as chains of mutually coupled spin-Hall nano-oscillators.

  1. Advances in islet cell biology: from stem cell differentiation to clinical transplantation: conference report.

    PubMed

    Kandeel, Fouad; Smith, Craig V; Todorov, Ivan; Mullen, Yoko

    2003-10-01

    The 3rd Annual Rachmiel Levine Symposium entitled "Advances in Islet Cell Biology-From Stem Cell Differentiation to Clinical Transplantation" was organized by the Department of Diabetes, Endocrinology and Metabolism at the City of Hope National Medical Center, with the support of the Southern California Islet Cell Resources Center, American Diabetes Association-David Shapiro Research Fund, Ross Foundation, the National Center for Research Resources (NCRR), and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health. The symposium was held at the Hilton Anaheim Hotel in Anaheim, CA, in October 2002, and was attended by nearly 400 participants from 23 countries and 30 U.S. states. The symposium consisted of 11 sessions focusing on 3 areas: (1) pancreas and islet cell differentiation and islet generation, (2) beta cell biology and insulin synthesis and/or secretion, and (3) pancreatic islet transplantation in patients with type I diabetes. Thirty-nine world experts lectured on the most current information in each field. Fifty-three abstracts were selected for presentation and discussed at the poster session. The first author of each of the top 10 posters received a Young Investigator Travel Award provided by the National Center for Research Resources and the Southern California Islet Cell Resources Center. The symposium also offered special Meet the Professor sessions, which gave the attendees an opportunity to closely interact with the participating speakers of the day.

  2. Hematopoietic specification from human pluripotent stem cells: current advances and challenges toward de novo generation of hematopoietic stem cells.

    PubMed

    Slukvin, Igor I

    2013-12-12

    Significant advances in cellular reprogramming technologies and hematopoietic differentiation from human pluripotent stem cells (hPSCs) have already enabled the routine production of multiple lineages of blood cells in vitro and opened novel opportunities to study hematopoietic development, model genetic blood diseases, and manufacture immunologically matched cells for transfusion and cancer immunotherapy. However, the generation of hematopoietic cells with robust and sustained multilineage engraftment has not been achieved. Here, we highlight the recent advances in understanding the molecular and cellular pathways leading to blood development from hPSCs and discuss potential approaches that can be taken to facilitate the development of technologies for de novo production of hematopoietic stem cells.

  3. Multilayer thin film Hall effect device

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N. (Inventor); Sisk, R. Charles (Inventor)

    1994-01-01

    A Hall effect device and a method of obtaining a magnetic field map of a magnetic body with the Hall effect device are presented. The device comprises: (1) a substrate, (2) a first layer having a first Hall coefficient deposited over the substrate, and (3) a second layer having a second Hall coefficient deposited over the first layer, the first and second layers cooperating to create, in the Hall effect device, a third Hall coefficient different from the first and second Hall coefficients. Creation of the third Hall coefficient by cooperation of the first and second layers allows use of materials for the first and second layers that were previously unavailable for Hall effect devices due to their relatively weak Hall coefficient.

  4. Crizotinib for Advanced Non-Small Cell Lung Cancer

    Cancer.gov

    A summary of results from an international phase III clinical trial that compared crizotinib versus chemotherapy in previously treated patients with advanced lung cancer whose tumors have an EML4-ALK fusion gene.

  5. Martin Hall Receives Inventors Award

    NASA Technical Reports Server (NTRS)

    1965-01-01

    In this photograph, Marshall Space Flight Center Director, Dr. Wernher von Braun, presents a Co-Inventor's award to MSFC employee Martin Hall of the Mechanical Engineering Laboratory during the NASA Anniversary ceremony.

  6. Overview of NASA Iodine Hall Thruster Propulsion System Development

    NASA Technical Reports Server (NTRS)

    Smith, Timothy D.; Kamhawi, Hani; Hickman, Tyler; Haag, Thomas; Dankanich, John; Polzin, Kurt; Byrne, Lawrence; Szabo, James

    2016-01-01

    NASA is continuing to invest in advancing Hall thruster technologies for implementation in commercial and government missions. The most recent focus has been on increasing the power level for large-scale exploration applications. However, there has also been a similar push to examine applications of electric propulsion for small spacecraft in the range of 300 kg or less. There have been several recent iodine Hall propulsion system development activities performed by the team of the NASA Glenn Research Center, the NASA Marshall Space Flight Center, and Busek Co. Inc. In particular, the work focused on qualification of the Busek 200-W BHT-200-I and development of the 600-W BHT-600-I systems. This paper discusses the current status of iodine Hall propulsion system developments along with supporting technology development efforts.

  7. Optimization of Cylindrical Hall Thrusters

    SciTech Connect

    Yevgeny Raitses, Artem Smirnov, Erik Granstedt, and Nathaniel J. Fi

    2007-07-24

    The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation. __________________________________________________

  8. Optimization of Cylindrical Hall Thrusters

    SciTech Connect

    Yevgeny Raitses, Artem Smirnov, Erik Granstedt, and Nathaniel J. Fisch

    2007-11-27

    The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation.

  9. ADVANCES IN THE USE OF STEM CELLS IN ORTHOPEDICS

    PubMed Central

    Cristante, Alexandre Fogaça; Narazaki, Douglas Kenji

    2015-01-01

    Primordial cells or stem cells are multipotent undifferentiated cells with the capacity to originate any type of cell in the organism. They may have their origins in the blastocyst and thus are classified as embryonic, or tissues developed in fetuses, newborns or adults and thus are known as somatic stem cells. Bone marrow is one of the main locations for isolating primordial cells, and there are two lineages: hematopoietic and mesenchymal progenitor cells. There are several uses for these undifferentiated cells in orthopedics, going from cartilaginous lesions in osteoarthrosis, osteochondritis dissecans and patellar chondromalacia, to bone lesions like in pseudarthrosis or bone losses, or nerve lesions like in spinal cord trauma. Studying stem cells is probably the most promising field of study of all within medicine, and this is shortly going to revolutionize all medical specialties (both clinical and surgical) and thus provide solutions for diseases that today are difficult to deal with. PMID:27027022

  10. Recruitment of natural killer cells in advanced stages of endogenously arising B-cell lymphoma: implications for therapeutic cell transfer.

    PubMed

    Przewoznik, Margarethe; Hömberg, Nadine; Naujoks, Marcella; Pötzl, Johann; Münchmeier, Niklas; Brenner, Christoph D; Anz, David; Bourquin, Carole; Nelson, Peter J; Röcken, Martin; Mocikat, Ralph

    2012-04-01

    During inflammation and in transplantable tumor models, natural killer (NK) cells are recruited to pathologic tissues and activated to produce proinflammatory cytokines favoring adaptive immune responses of the T-helper type 1 (Th1) type. Interferon (IFN)-γ is needed to induce chemokines that attract NK cells in transplanted tumors. Nothing, however, is known on NK-cell migration in spontaneous tumors. As effective recruitment is a prerequisite for therapeutic NK-cell transfer, we investigated the cytokine milieu and the mechanisms that are instrumental for NK-cell accumulation in an endogenous tumor model. We make use of λ-myc transgenic mice that harbor the c-myc oncogene and develop spontaneous B-cell lymphoma. In contrast to lymphomas induced by tumor cell injection, virtually no IFN-γ produced by NK or by other cells was present in the tumor environment, particularly in advanced stages. Dendritic cells showed an impaired expression of interleukin-12, which is suggestive of deficient Th1 priming. The IFN-γ-dependent chemokines CXCL9 and CXCL10 were pivotal for NK-cell migration in the endogenous lymphoma model. Although IFN-γ was absent in late tumor stages, there was still expression of CXCL9 and CXCL10 with an ongoing influx of NK cells. The results demonstrate that transplantable tumor models do not reflect the situation as found in endogenously arising neoplasia, because in the latter, effective Th1 and cytotoxic T-lymphocyte responses are presumably not induced because of impaired IFN-γ production. The data also suggest that CXCL9 and CXCL10 production and NK-cell migration become independent of IFN-γ during tumor progression, and therefore support approaches of adoptive NK-cell transfer that hold promise for treatment of cancer. PMID:22421939

  11. Advances in understanding the cell types and approaches used for generating induced pluripotent stem cells

    PubMed Central

    2014-01-01

    Successfully reprogramming somatic cells to a pluripotent state generates induced pluripotent stem (iPS) cells (or iPSCs), which have extensive self-renewal capacity like embryonic stem cells (ESCs). iPSCs can also generate daughter cells that can further undergo differentiation into various lineages or terminally differentiate to reach their final functional state. The discovery of how to produce iPSCs opened a new field of stem cell research with both intellectual and therapeutic benefits. The huge potential implications of disease-specific or patient-specific iPSCs have impelled scientists to solve problems hindering their applications in clinical medicine, especially the issues of convenience and safety. To determine the range of tissue types amenable to reprogramming as well as their particular characteristics, cells from three embryonic germ layers have been assessed, and the advantages that some tissue origins have over fibroblast origins concerning efficiency and accessibility have been elucidated. To provide safe iPSCs in an efficient and convenient way, the delivery systems and combinations of inducing factors as well as the chemicals used to generate iPSCs have also been significantly improved in addition to the efforts on finding better donor cells. Currently, iPSCs can be generated without c-Myc and Klf4 oncogenes, and non-viral delivery integration-free chemically mediated reprogramming methods have been successfully employed with relatively satisfactory efficiency. This paper will review recent advances in iPS technology by highlighting tissue origin and generation of iPSCs. The obstacles that need to be overcome for clinical applications of iPSCs are also discussed. PMID:25037625

  12. Advances in understanding the cell types and approaches used for generating induced pluripotent stem cells.

    PubMed

    Li, Jun; Song, Wei; Pan, Guangjin; Zhou, Jun

    2014-01-01

    Successfully reprogramming somatic cells to a pluripotent state generates induced pluripotent stem (iPS) cells (or iPSCs), which have extensive self-renewal capacity like embryonic stem cells (ESCs). iPSCs can also generate daughter cells that can further undergo differentiation into various lineages or terminally differentiate to reach their final functional state. The discovery of how to produce iPSCs opened a new field of stem cell research with both intellectual and therapeutic benefits. The huge potential implications of disease-specific or patient-specific iPSCs have impelled scientists to solve problems hindering their applications in clinical medicine, especially the issues of convenience and safety. To determine the range of tissue types amenable to reprogramming as well as their particular characteristics, cells from three embryonic germ layers have been assessed, and the advantages that some tissue origins have over fibroblast origins concerning efficiency and accessibility have been elucidated. To provide safe iPSCs in an efficient and convenient way, the delivery systems and combinations of inducing factors as well as the chemicals used to generate iPSCs have also been significantly improved in addition to the efforts on finding better donor cells. Currently, iPSCs can be generated without c-Myc and Klf4 oncogenes, and non-viral delivery integration-free chemically mediated reprogramming methods have been successfully employed with relatively satisfactory efficiency. This paper will review recent advances in iPS technology by highlighting tissue origin and generation of iPSCs. The obstacles that need to be overcome for clinical applications of iPSCs are also discussed.

  13. Cell line development for biomanufacturing processes: recent advances and an outlook.

    PubMed

    Le, Huong; Vishwanathan, Nandita; Jacob, Nitya M; Gadgil, Mugdha; Hu, Wei-Shou

    2015-08-01

    At the core of a biomanufacturing process for recombinant proteins is the production cell line. It influences the productivity and product quality. Its characteristics also dictate process development, as the process is optimized to complement the producing cell to achieve the target productivity and quality. Advances in the past decade, from vector design to cell line screening, have greatly expanded our capability to attain producing cell lines with certain desired traits. Increasing availability of genomic and transcriptomic resources for industrially important cell lines coupled with advances in genome editing technology have opened new avenues for cell line development. These developments are poised to help biosimilar manufacturing, which requires targeting pre-defined product quality attributes, e.g., glycoform, to match the innovator's range. This review summarizes recent advances and discusses future possibilities in this area.

  14. A brief review of recent advances in stem cell biology

    PubMed Central

    Chen, Jinhui; Zhou, Libing; Pan, Su-yue

    2014-01-01

    Stem cells have the remarkable potential to develop into many different cell types, essentially without limit to replenish other cells as long as the person or animal is still alive, offering immense hope of curing Alzheimer's disease, repairing damaged spinal cords, treating kidney, liver and lung diseases and making damaged hearts whole. Until recently, scientists primarily worked with two kinds of stem cells from animals and humans: embryonic stem cells and non-embryonic “somatic” or “adult” stem cells. Recent breakthrough make it possible to convert or “reprogram” specialized adult cells to assume a stem stem-like cells with different technologies. The review will briefly discuss the recent progresses in this area. PMID:25206872

  15. [Advances in microbial solar cells--A review].

    PubMed

    Guo, Xiaoyun; Yu, Changping; Zheng, Tianling

    2015-08-01

    The energy crisis has become one of the major problems hindering the development of the world. The emergence of microbial fuel cells provides a new solution to the energy crisis. Microbial solar cells, integrating photosynthetic organisms such as plants and microalgae into microbial fuel cells, can convert solar energy into electrical energy. Microbial solar cell has steady electric energy, and broad application prospects in wastewater treatment, biodiesel processing and intermediate metabolites production. Here we reviewed recent progress of microbial solar cells from the perspective of the role of photosynthetic organisms in microbial fuel cells, based on a vast amount of literature, and discussed their advantages and deficiency. At last, brief analysis of the facing problems and research needs of microbial fuel cells are undertaken. This work was expected to be beneficial for the application of the microbial solar cells technology.

  16. The Performance of Advanced III-V Solar Cells

    NASA Technical Reports Server (NTRS)

    Mueller, Robert L.; Gaddy, Edward; Day, John H. (Technical Monitor)

    2002-01-01

    Test results show triple junction solar cells with efficiencies as high as 27% at 28C and 136.7 mw/sq cm. Triple junction cells also achieve up to 27.5% at -120 C and 5 mw/sq cm, conditions applicable to missions to Jupiter. Some triple junction cells show practically no degradation as a result of Low Intensity Low Temperature (LILT) effects, while others show some; this degradation can be overcome with minor changes to the cell design.

  17. Microparticle, nanoparticle, and stem cell-based oxygen carriers as advanced blood substitutes.

    PubMed

    Tao, Zhimin; Ghoroghchian, P Peter

    2014-09-01

    Here, we discuss recent advances in the development of artificial red blood cell (RBC) substitutes, illustrating lessons learned from initial attempts using perfluorocarbon (PFC) emulsions and acellular hemoglobin-based oxygen carriers (HBOCs). We also highlight novel oxygen-containing microparticles, nanoparticles, and stem cell-derived RBC products, with emphasis on improvements in biocompatibility and oxygen delivery. In addition, we envision future developments for the rational design of advanced blood substitutes that aim to address unmet clinical needs.

  18. Bismuth nano-Hall Sensor for Scanning Hall Probe Microscopy

    NASA Astrophysics Data System (ADS)

    Sonusen, Selda; Dede, Munir; Oral, Ahmet

    2013-03-01

    Scanning hall probe microscopy (SHPM) is a non invasive and quantitative magnetic imaging technique, which provides high spatial (50nm) and magnetic resolution to image magnetic and superconducting materials. SHPM can also work under high magnetic field and in a wide temperature (range 30mK -300K). Since Bismuth is a semimetal with a concentration five orders of magnitude lower than metals and negligible surface charge depletion effect, it is an alternative material for Hall probes for SHPM. In this work, we fabricated Bi Hall sensors with different sizes ranging from 10nm to 50nm- by electron beam lithography. The sensors are calibrated -under high magnetic fields -and the minimum detectable magnetic field was measured in a broad temperature range, 4-300K. In addition, 50nm Bi Hall sensors are -used for imaging magnetic domains in Iron Garnet thin film crystal. A detailed electrical characterization and performance of the 25nm and 50nm Hall Sensors will also be presented.

  19. Microfluidic cell sorting: a review of the advances in the separation of cells from debulking to rare cell isolation.

    PubMed

    Shields, C Wyatt; Reyes, Catherine D; López, Gabriel P

    2015-03-01

    Accurate and high throughput cell sorting is a critical enabling technology in molecular and cellular biology, biotechnology, and medicine. While conventional methods can provide high efficiency sorting in short timescales, advances in microfluidics have enabled the realization of miniaturized devices offering similar capabilities that exploit a variety of physical principles. We classify these technologies as either active or passive. Active systems generally use external fields (e.g., acoustic, electric, magnetic, and optical) to impose forces to displace cells for sorting, whereas passive systems use inertial forces, filters, and adhesion mechanisms to purify cell populations. Cell sorting on microchips provides numerous advantages over conventional methods by reducing the size of necessary equipment, eliminating potentially biohazardous aerosols, and simplifying the complex protocols commonly associated with cell sorting. Additionally, microchip devices are well suited for parallelization, enabling complete lab-on-a-chip devices for cellular isolation, analysis, and experimental processing. In this review, we examine the breadth of microfluidic cell sorting technologies, while focusing on those that offer the greatest potential for translation into clinical and industrial practice and that offer multiple, useful functions. We organize these sorting technologies by the type of cell preparation required (i.e., fluorescent label-based sorting, bead-based sorting, and label-free sorting) as well as by the physical principles underlying each sorting mechanism. PMID:25598308

  20. Microfluidic Cell Sorting: A Review of the Advances in the Separation of Cells from Debulking to Rare Cell Isolation

    PubMed Central

    Shields, C. Wyatt; Reyes, Catherine D.; López, Gabriel P.

    2015-01-01

    Accurate and high throughput cell sorting is a critical enabling technology in molecular and cellular biology, biotechnology, and medicine. While conventional methods can provide high efficiency sorting in short timescales, advances in microfluidics have enabled the realization of miniaturized devices offering similar capabilities that exploit a variety of physical principles. We classify these technologies as either active or passive. Active systems generally use external fields (e.g., acoustic, electric, magnetic, and optical) to impose forces to displace cells for sorting, whereas passive systems use inertial forces, filters, and adhesion mechanisms to purify cell populations. Cell sorting on microchips provides numerous advantages over conventional methods by reducing the size of necessary equipment, eliminating potentially biohazardous aerosols, and simplifying the complex protocols commonly associated with cell sorting. Additionally, microchip devices are well suited for parallelization, enabling complete lab-on-a-chip devices for cellular isolation, analysis, and experimental processing. In this review, we examine the breadth of microfluidic cell sorting technologies, while focusing on those that offer the greatest potential for translation into clinical and industrial practice and that offer multiple, useful functions. We organize these sorting technologies by the type of cell preparation required (i.e., fluorescent label-based sorting, bead-based sorting, and label-free sorting) as well as by the physical principles underlying each sorting mechanism. PMID:25598308

  1. Iodine Hall Thruster

    NASA Technical Reports Server (NTRS)

    Szabo, James

    2015-01-01

    Iodine enables dramatic mass and cost savings for lunar and Mars cargo missions, including Earth escape and near-Earth space maneuvers. The demonstrated throttling ability of iodine is important for a singular thruster that might be called upon to propel a spacecraft from Earth to Mars or Venus. The ability to throttle efficiently is even more important for missions beyond Mars. In the Phase I project, Busek Company, Inc., tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high-flow iodine feed system and supported by an existing Busek hollow cathode flowing xenon gas. The Phase I propellant feed system was evolved from a previously demonstrated laboratory feed system. Throttling of the thruster between 2 and 11 kW at 200 to 600 V was demonstrated. Testing showed that the efficiency of iodine fueled BHT-8000 is the same as with xenon, with iodine delivering a slightly higher thrust-to-power (T/P) ratio. In Phase II, a complete iodine-fueled system was developed, including the thruster, hollow cathode, and iodine propellant feed system. The nominal power of the Phase II system is 8 kW; however, it can be deeply throttled as well as clustered to much higher power levels. The technology also can be scaled to greater than 100 kW per thruster to support megawatt-class missions. The target thruster efficiency for the full-scale system is 65 percent at high specific impulse (Isp) (approximately 3,000 s) and 60 percent at high thrust (Isp approximately 2,000 s).

  2. Optimizing the performance of advanced nonvolatile memories using differentiated cell source and drain implants

    NASA Astrophysics Data System (ADS)

    Duncan, Martin; Pansana, P.

    1995-09-01

    In order to satisfy the twin requirements of increased performance at low cost, a novel architecture that allows the differentiation of the source and drain implants of an EPROM cell without any additional processing steps has been developed. This cell is more immune to electrical stress than a standard cell during both programming and read cycles. In addition, this cell is inherently electrically shorter and therefore can be used to reduce die size in advanced EPROM devices.

  3. [Advances in the mechanism of mesenchymal stem cells in promoting wound healing].

    PubMed

    Zhu, Wenjing; Sun, Haobo; Lyu, Guozhong

    2015-12-01

    Mesenchymal stem cells possess the ability of self-renewal and multiple differentiation potential, thus exert immunomodulatory effect during tissue repair. Mesenchymal stem cells can stimulate angiogenesis and promote tissue repair through transdifferentiation and secreting a variety of growth factors and cytokines. This review outlines the advances in the mechanism of mesenchymal stem cells in promoting wound healing, including alleviation of inflammatory response, induction of angiogenesis, and promotion of migration of mesenchymal stem cells to the site of tissue injury.

  4. Single-cell RNA-seq: advances and future challenges

    PubMed Central

    Saliba, Antoine-Emmanuel; Westermann, Alexander J.; Gorski, Stanislaw A.; Vogel, Jörg

    2014-01-01

    Phenotypically identical cells can dramatically vary with respect to behavior during their lifespan and this variation is reflected in their molecular composition such as the transcriptomic landscape. Single-cell transcriptomics using next-generation transcript sequencing (RNA-seq) is now emerging as a powerful tool to profile cell-to-cell variability on a genomic scale. Its application has already greatly impacted our conceptual understanding of diverse biological processes with broad implications for both basic and clinical research. Different single-cell RNA-seq protocols have been introduced and are reviewed here—each one with its own strengths and current limitations. We further provide an overview of the biological questions single-cell RNA-seq has been used to address, the major findings obtained from such studies, and current challenges and expected future developments in this booming field. PMID:25053837

  5. Advances in hepatic stem/progenitor cell biology

    PubMed Central

    Verhulst, Stefaan; Best, Jan; van Grunsven, Leo A.; Dollé, Laurent

    2015-01-01

    The liver is famous for its strong regenerative capacity, employing different modes of regeneration according to type and extent of injury. Mature liver cells are able to proliferate in order to replace the damaged tissue allowing the recovery of the parenchymal function. In more severe scenarios hepatocytes are believed to arise also from a facultative liver progenitor cell compartment. In human, severe acute liver failure and liver cirrhosis are also both important clinical targets in which regeneration is impaired, where the role of this stem cell compartment seems more convincing. In animal models, the current state of ambiguity regarding the identity and role of liver progenitor cells in liver physiology dampens the enthusiasm for the potential use of these cells in regenerative medicine. The aim of this review is to give the basics of liver progenitor cell biology and discuss recent results vis-à-vis their identity and contribution to liver regeneration. PMID:26600740

  6. Advanced alternate planar geometry solid oxide fuel cells

    SciTech Connect

    Prouse, D.; Elangovan, S.; Khandkar, A. ); Donelson, R.; Marianowski, L. )

    1989-01-01

    During this quarter, progress was made at Ceramatec in seal development and conductivity measurements of YIG compositions. A creep test was completed on the porous/dense/porous triilayer. IGT provided a discussion on possible interconnect materials. The following tasks are reported on: cell design analysis, program liaison and test facility preparation, cell component fabrication/development, out-of-cell tests. 9 figs, 2 tabs.

  7. Advanced alternate planar geometry solid oxide fuel cells. Final report

    SciTech Connect

    Elangovan, S.; Prouse, D.; Khandkar, A.; Donelson, R.; Marianowski, L.

    1992-11-01

    The potential of high temperature Solid Oxide Fuel Cells as high performance, high efficiency energy conversion device is well known. Investigation of several cell designs have been undertaken by various researchers to derive the maximum performance benefit from the device while maintaining a lower cost of production to meet the commercialization cost target. The present investigation focused on the planar SOFC design which allows for the use of mature low cost production processes to be employed. A novel design concept was investigated which allows for improvements in performance through increased interface stability, and lowering of cost through enhanced structural integrity and the use of low cost metal interconnects. The new cell design consisted of a co-sintered porous/dense/porous zirconia layer with the electrode material infiltrated into the porous layers. The two year program conducted by a team involving Ceramatec and the Institute of Gas Technology, culminated in a multi-cell stack test that exhibited high performance. Considerable progress was achieved in the selection of cell components, and establishing and optimizing the cell and stack fabrication parameters. It was shown that the stack components exhibited high conductivities and low creep at the operating temperature. The inter-cell resistive losses were shown to be small through out-of-cell characterization. The source of performance loss was identified to be the anode electrolyte interface. This loss however can be minimized by improving the anode infiltration technique. Manifolding and sealing of the planar devices posed considerable challenge. Even though the open circuit voltage was 250 mV/cell lower than theoretical, the two cell stack had a performance of 300 mA/cm{sup 2} at 0.4V/cell with an area specific resistance of 1 {Omega}-cm{sup 2}/cell. improvements in manifolding are expected to provide much higher performance.

  8. Advanced alternate planar geometry solid oxide fuel cells

    SciTech Connect

    Elangovan, S.; Prouse, D.; Khandkar, A.; Donelson, R.; Marianowski, L. )

    1992-11-01

    The potential of high temperature Solid Oxide Fuel Cells as high performance, high efficiency energy conversion device is well known. Investigation of several cell designs have been undertaken by various researchers to derive the maximum performance benefit from the device while maintaining a lower cost of production to meet the commercialization cost target. The present investigation focused on the planar SOFC design which allows for the use of mature low cost production processes to be employed. A novel design concept was investigated which allows for improvements in performance through increased interface stability, and lowering of cost through enhanced structural integrity and the use of low cost metal interconnects. The new cell design consisted of a co-sintered porous/dense/porous zirconia layer with the electrode material infiltrated into the porous layers. The two year program conducted by a team involving Ceramatec and the Institute of Gas Technology, culminated in a multi-cell stack test that exhibited high performance. Considerable progress was achieved in the selection of cell components, and establishing and optimizing the cell and stack fabrication parameters. It was shown that the stack components exhibited high conductivities and low creep at the operating temperature. The inter-cell resistive losses were shown to be small through out-of-cell characterization. The source of performance loss was identified to be the anode electrolyte interface. This loss however can be minimized by improving the anode infiltration technique. Manifolding and sealing of the planar devices posed considerable challenge. Even though the open circuit voltage was 250 mV/cell lower than theoretical, the two cell stack had a performance of 300 mA/cm[sup 2] at 0.4V/cell with an area specific resistance of 1 [Omega]-cm[sup 2]/cell. improvements in manifolding are expected to provide much higher performance.

  9. Recent advances in microbial single cell genomics technology and applications

    NASA Astrophysics Data System (ADS)

    Stepanauskas, R.

    2015-12-01

    Single cell genomics is increasingly utilized as a powerful tool to decipher the metabolic potential, evolutionary histories and in situ interactions of environmental microorganisms. I will present several new developments of this exciting technology, which improve genomic data recovery from individual cells and allow its integration with cell's phenotypic properties. I will also demonstrate how these new technical capabilities help understanding the biology of the "microbial dark matter" inhabiting marine and terrestrial subsurface environments.

  10. Recent advances in carbon nanotube-based enzymatic fuel cells.

    PubMed

    Cosnier, Serge; Holzinger, Michael; Le Goff, Alan

    2014-01-01

    This review summarizes recent trends in the field of enzymatic fuel cells. Thanks to the high specificity of enzymes, biofuel cells can generate electrical energy by oxidation of a targeted fuel (sugars, alcohols, or hydrogen) at the anode and reduction of oxidants (O2, H2O2) at the cathode in complex media. The combination of carbon nanotubes (CNT), enzymes and redox mediators was widely exploited to develop biofuel cells since the electrons involved in the bio-electrocatalytic processes can be efficiently transferred from or to an external circuit. Original approaches to construct electron transfer based CNT-bioelectrodes and impressive biofuel cell performances are reported as well as biomedical applications.

  11. Effect of LEO cycling on 125 Ah advanced design IPV nickel-hydrogen battery cells

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1990-01-01

    An advanced 125 Ah individual pressure vessel (IPV) nickel-hydrogen cell was designed. The primary function of the advanced cell, is to store and deliver energy for long term, low earth-orbit (LEO) spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent potassium hydroxide (KOH) electrolyte, (2) use of a patented catalyzed wall wick, (3) use of serrated edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management, and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion. Six 125 Ah flight cells based on this design were fabricated by Eagle-Picher. Three of the cells contain all of the advanced features (test cells) and three are the same as the test cells except they don't have catalyst on the wall wick (control cells). All six cells are in the process of being evaluated in a LEO cycle life test. The cells have accumulated about 4700 LEO cycles (60 percent DOD 10 C). There have been no cell failures, the catalyzed wall wick cells however, are performing better.

  12. Validation test of advanced technology for IPV nickel-hydrogen flight cells: Update

    NASA Astrophysics Data System (ADS)

    Smithrick, John J.; Hall, Stephen W.

    1992-05-01

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts with the intention of improving cycle life and performance. One advancement was to use 26 percent potassium hydroxide (KOH) electrolyte to improve cycle life. Another advancement was to modify the state-of-the-art cell design to eliminate identified failure modes. The modified design is referred to as the advanced design. A breakthrough in the low-earth-orbit (LEO) cycle life of IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3,500 cycles for cells containing 31 percent KOH. The boiler plate test results are in the process of being validated using flight hardware and real time LEO testing at the Naval Weapons Support Center (NWSC), Crane, Indiana under a NASA Lewis Contract. An advanced 125 Ah IPV nickel-hydrogen cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term, LEO spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent KOH electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are: extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion. The advanced cell design is in the process of being validated using real time LEO cycle life testing of NWSC, Crane, Indiana. An update of validation test results confirming this technology is presented.

  13. Validation test of advanced technology for IPV nickel-hydrogen flight cells: Update

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1992-01-01

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts with the intention of improving cycle life and performance. One advancement was to use 26 percent potassium hydroxide (KOH) electrolyte to improve cycle life. Another advancement was to modify the state-of-the-art cell design to eliminate identified failure modes. The modified design is referred to as the advanced design. A breakthrough in the low-earth-orbit (LEO) cycle life of IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3,500 cycles for cells containing 31 percent KOH. The boiler plate test results are in the process of being validated using flight hardware and real time LEO testing at the Naval Weapons Support Center (NWSC), Crane, Indiana under a NASA Lewis Contract. An advanced 125 Ah IPV nickel-hydrogen cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term, LEO spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent KOH electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are: extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion. The advanced cell design is in the process of being validated using real time LEO cycle life testing of NWSC, Crane, Indiana. An update of validation test results confirming this technology is presented.

  14. Advances in ethanol production using immobilized cell systems

    SciTech Connect

    Margaritis, A.; Merchant, F.J.A.

    1984-01-01

    The application of immobilized cell systems for the production of ethanol has resulted in substantial improvements in the efficiency of the process when compared to the traditional free cell system. In this review, the various methods of cell immobilization employed in ethanol production systems have been described in detail. Their salient features, performance characteristics, advantages and limitations have been critically assessed. More recently, these immobilized cell systems have also been employed for the production of ethanol from non-conventional feedstocks such as Jerusalem artichoke extracts, cheese whey, cellulose, cellobiose and xylose. Ethanol production by immobilized yeast and bacterial cells has been attempted in various bioreactor types. Although most of these studies have been carried out using laboratory scale prototype bioreactors, it appears that only fluidized bed, horizontally packed bed bioreactors and tower fermenters may find application on scale-up. Several studies have indicated that upon immobilization, yeast cells performing ethanol fermentation exhibit more favourable physiological and metabolic properties. This, in addition to substantial improvements in ethanol productivities by immobilized cell systems, is indicative of the fact that future developments in the production of ethanol and alcoholic beverages will be directed towards the use of immobilized cell systems. 291 references.

  15. Development of advanced silicon solar cells for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Lillington, David R.

    1990-01-01

    This report describes the development of large area high efficiency wrapthrough solar cells for Space Station Freedom. The goal of this contract was the development and fabrication of 8 x 8 cm coplanar back contact solar cells with a minimum output of 1.039 watts/cell. The first task in this program was a modeling study to determine the optimum configuration of the cell and to study the effects of surface passivation, substrate resistivity, and back surface field on the BOL and EOL performance. In addition, the optical stack, including the cell cover, AR coatings, and Kapton blanket, was modeled to optimize 'on orbit' operation. The second phase was a manufacturing development phase to develop high volume manufacturing processes for the reliable production of low recombination velocity boron back surface fields, techniques to produce smooth, low leakage wrapthrough holes, passivation, photoresist application methods, and metallization schemes. The final portion of this program was a pilot production phase. Seven hundred solar cells were delivered in this phase. At the end of the program, cells with average efficiencies over 13 percent were being produced with power output in excess of 1.139 watts/cell, thus substantially exceeding the program goal.

  16. Electric utility acid fuel cell stack technology advancement

    NASA Technical Reports Server (NTRS)

    Congdon, J. V.; Goller, G. J.; Greising, G. J.; Obrien, J. J.; Randall, S. A.; Sandelli, G. J.; Breault, R. D.; Austin, G. W.; Bopse, S.; Coykendall, R. D.

    1984-01-01

    The principal effort under this program was directed at the fuel cell stack technology required to accomplish the initial feasibility demonstrations of increased cell stack operating pressures and temperatures, increased cell active area, incorporation of the ribbed substrate cell configuration at the bove conditions, and the introduction of higher performance electrocatalysts. The program results were successful with the primary accomplishments being: (1) fabrication of 10 sq ft ribbed substrate, cell components including higher performing electrocatalysts; (2) assembly of a 10 sq ft, 30-cell short stack; and (3) initial test of this stack at 120 psia and 405 F. These accomplishments demonstrate the feasibility of fabricating and handling large area cells using materials and processes that are oriented to low cost manufacture. An additional accomplishment under the program was the testing of two 3.7 sq ft short stacks at 12 psia/405 F to 5400 and 4500 hours respectively. These tests demonstrate the durability of the components and the cell stack configuration to a nominal 5000 hours at the higher pressure and temperature condition planned for the next electric utility power plant.

  17. Recent advancements in cloning by somatic cell nuclear transfer

    PubMed Central

    Ogura, Atsuo; Inoue, Kimiko; Wakayama, Teruhiko

    2013-01-01

    Somatic cell nuclear transfer (SCNT) cloning is the sole reproductive engineering technology that endows the somatic cell genome with totipotency. Since the first report on the birth of a cloned sheep from adult somatic cells in 1997, many technical improvements in SCNT have been made by using different epigenetic approaches, including enhancement of the levels of histone acetylation in the chromatin of the reconstructed embryos. Although it will take a considerable time before we fully understand the nature of genomic programming and totipotency, we may expect that somatic cell cloning technology will soon become broadly applicable to practical purposes, including medicine, pharmaceutical manufacturing and agriculture. Here we review recent progress in somatic cell cloning, with a special emphasis on epigenetic studies using the laboratory mouse as a model. PMID:23166393

  18. Recent advancements in cloning by somatic cell nuclear transfer.

    PubMed

    Ogura, Atsuo; Inoue, Kimiko; Wakayama, Teruhiko

    2013-01-01

    Somatic cell nuclear transfer (SCNT) cloning is the sole reproductive engineering technology that endows the somatic cell genome with totipotency. Since the first report on the birth of a cloned sheep from adult somatic cells in 1997, many technical improvements in SCNT have been made by using different epigenetic approaches, including enhancement of the levels of histone acetylation in the chromatin of the reconstructed embryos. Although it will take a considerable time before we fully understand the nature of genomic programming and totipotency, we may expect that somatic cell cloning technology will soon become broadly applicable to practical purposes, including medicine, pharmaceutical manufacturing and agriculture. Here we review recent progress in somatic cell cloning, with a special emphasis on epigenetic studies using the laboratory mouse as a model.

  19. Advances in Materials and System Technology for Portable Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R.

    2007-01-01

    This viewgraph presentation describes the materials and systems engineering used for portable fuel cells. The contents include: 1) Portable Power; 2) Technology Solution; 3) Portable Hydrogen Systems; 4) Direct Methanol Fuel Cell; 5) Direct Methanol Fuel Cell System Concept; 6) Overview of DMFC R&D at JPL; 7) 300-Watt Portable Fuel Cell for Army Applications; 8) DMFC units from Smart Fuel Cell Inc, Germany; 9) DMFC Status and Prospects; 10) Challenges; 11) Rapid Screening of Well-Controlled Catalyst Compositions; 12) Screening of Ni-Zr-Pt-Ru alloys; 13) Issues with New Membranes; 14) Membranes With Reduced Methanol Crossover; 15) Stacks; 16) Hybrid DMFC System; 17) Small Compact Systems; 18) Durability; and 19) Stack and System Parameters for Various Applications.

  20. Research Advancements in Porcine Derived Mesenchymal Stem Cells.

    PubMed

    Bharti, Dinesh; Shivakumar, Sharath Belame; Subbarao, Raghavendra Baregundi; Rho, Gyu-Jin

    2016-01-01

    In the present era of stem cell biology, various animals such as Mouse, Bovine, Rabbit and Porcine have been tested for the efficiency of their mesenchymal stem cells (MSCs before their actual use for stem cell based application in humans. Among them pigs have many similarities to humans in the form of organ size, physiology and their functioning, therefore they have been considered as a valuable model system for in vitro studies and preclinical assessments. Easy assessability, few ethical issues, successful MSC isolation from different origins like bone marrow, skin, umbilical cord blood, Wharton's jelly, endometrium, amniotic fluid and peripheral blood make porcine a good model for stem cell therapy. Porcine derived MSCs (pMSCs have shown greater in vitro differentiation and transdifferention potential towards mesenchymal lineages and specialized lineages such as cardiomyocytes, neurons, hepatocytes and pancreatic beta cells. Immunomodulatory and low immunogenic profiles as shown by autologous and heterologous MSCs proves them safe and appropriate models for xenotransplantation purposes. Furthermore, tissue engineered stem cell constructs can be of immense importance in relation to various osteochondral defects which are difficult to treat otherwise. Using pMSCs successful treatment of various disorders like Parkinson's disease, cardiac ischemia, hepatic failure, has been reported by many studies. Here, in this review we highlight current research findings in the area of porcine mesenchymal stem cells dealing with their isolation methods, differentiation ability, transplantation applications and their therapeutic potential towards various diseases. PMID:26201864

  1. Recent Advances in Electrical Resistance Preheating of Aluminum Reduction Cells

    NASA Astrophysics Data System (ADS)

    Ali, Mohamed Mahmoud; Kvande, Halvor

    2016-06-01

    ABSTRACT There are two mainpreheating methods that are used nowadays for aluminum reduction cells. One is based on electrical resistance preheating with a thin bed of small coke and/or graphite particles between the anodes and the cathode carbon blocks. The other is flame preheating, where two or more gas or oil burners are used. Electrical resistance preheating is the oldest method, but is still frequently used by different aluminum producers. Many improvements have been made to this method by different companies over the last decade. In this paper, important points pertaining to the preparation and preheating of these cells, as well as measurements made during the preheating process and evaluation of the performance of the preheating, are illustrated. The preheating times of these cells were found to be between 36 h and 96 h for cell currents between 176 kA and 406 kA, while the resistance bed thickness was between 13 mm and 60 mm. The average cathode surface temperature at the end of the preheating was usually between 800°C and 950°C. The effect of the preheating methods on cell life is unclear and no quantifiable conclusions can be drawn. Some works carried out in the mathematical modeling area are also discussed. It is concluded that there is a need for more studies with real situations for preheated cells on the basis of actual measurements. The expected development in electrical resistance preheating of aluminum reduction cells is also summarized.

  2. Advances in tubular solid oxide fuel cell technology

    SciTech Connect

    Singhal, S.C.

    1996-12-31

    The design, materials and fabrication processes for the earlier technology Westinghouse tubular geometry cell have been described in detail previously. In that design, the active cell components were deposited in the form of thin layers on a ceramic porous support tube (PST). The tubular design of these cells and the materials used therein have been validated by successful electrical testing for over 65,000 h (>7 years). In these early technology PST cells, the support tube, although sufficiently porous, presented an inherent impedance to air flow toward air electrode. In order to reduce such impedance to air flow, the wall thickness of the PST was first decreased from the original 2 mm (the thick-wall PST) to 1.2 mm (the thin-wall PST). The calcia-stabilized zirconia support tube has now been completely eliminated and replaced by a doped lanthanum manganite tube in state-of-the-art SOFCs. This doped lanthanum manganite tube is extruded and sintered to about 30 to 35 percent porosity, and serves as the air electrode onto which the other cell components are fabricated in thin layer form. These latest technology cells are designated as air electrode supported (AES) cells.

  3. Validation test of 125 Ah advanced design IPV nickel-hydrogen flight cells

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1993-01-01

    An update of validation test results confirming the advanced design nickel-hydrogen cell is presented. An advanced 125 Ah individual pressure vessel (IPV) nickel-hydrogen cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term, Low-Earth-Orbit (LEO) spacecraft missions. The new features of this design, which are not incorporated in state-of-the-art design cells, are: (1) use of 26 percent rather than 31 percent potassium hydroxide (KOH) electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion. Six 125 Ah flight cells based on this design were fabricated by Eagle-Picher. Three of the cells contain all of the advanced features (test cells) and three are the same as the test cells except they do not have catalyst on the wall wick (control cells). All six cells are in the process of being evaluated in a LEO cycle life test at the Naval Weapons Support Center, Crane, IN, under a NASA Lewis Research Center contract. The catalyzed wall wick cells have been cycled for over 19000 cycles with no cell failures in the continuing test. Two of the noncatalyzed wall wick cells failed (cycles 9588 and 13,900).

  4. New advances in the mesenchymal stem cells therapy against skin flaps necrosis.

    PubMed

    Zhang, Fu-Gui; Tang, Xiu-Fa

    2014-09-26

    Mesenchymal stem cells (MSCs), multipotential cells that reside within the bone marrow, can be induced to differentiate into various cells, such as osteoblasts, adipocytes, chondrocytes, vascular endothelial progenitor cells, and other cell types. MSCs are being widely studied as potential cell therapy agents due to their angiogenic properties, which have been well established by in vitro and in vivo researches. Within this context, MSCs therapy appears to hold substantial promise, particularly in the treatment of conditions involving skin grafts, pedicle flaps, as well as free flaps described in literatures. The purpose of this review is to report the new advances and mechanisms underlying MSCs therapy against skin flaps necrosis.

  5. Recent Advances of Stem Cell Therapy for Retinitis Pigmentosa

    PubMed Central

    He, Yuxi; Zhang, Yan; Liu, Xin; Ghazaryan, Emma; Li, Ying; Xie, Jianan; Su, Guanfang

    2014-01-01

    Retinitis pigmentosa (RP) is a group of inherited retinal disorders characterized by progressive loss of photoreceptors and eventually leads to retina degeneration and atrophy. Until now, the exact pathogenesis and etiology of this disease has not been clear, and many approaches for RP therapies have been carried out in animals and in clinical trials. In recent years, stem cell transplantation-based attempts made some progress, especially the transplantation of bone marrow-derived mesenchymal stem cells (BMSCs). This review will provide an overview of stem cell-based treatment of RP and its main problems, to provide evidence for the safety and feasibility for further clinical treatment. PMID:25141102

  6. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss "small-group apprenticeships (SGAs)" as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments…

  7. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research.

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    Discusses small-group apprenticeships (SGAs) as a method for introducing cell culture techniques to high school participants. Teaches cell culture practices and introduces advance imaging techniques to solve various biomedical engineering problems. Clarifies and illuminates the value of small-group laboratory apprenticeships. (Author/KHR)

  8. Functional inclusion bodies produced in bacteria as naturally occurring nanopills for advanced cell therapies.

    PubMed

    Vázquez, Esther; Corchero, José L; Burgueño, Joan F; Seras-Franzoso, Joaquin; Kosoy, Ana; Bosser, Ramon; Mendoza, Rosa; Martínez-Láinez, Joan Marc; Rinas, Ursula; Fernández, Ester; Ruiz-Avila, Luis; García-Fruitós, Elena; Villaverde, Antonio

    2012-04-01

    Inclusion bodies (50-500 nm in diameter) produced in recombinant bacteria can be engineered to contain functional proteins with therapeutic potential. Upon exposure, these protein particles are efficiently internalized by mammalian cells and promote recovery from diverse stresses. Being fully biocompatible, inclusion bodies are a novel platform, as tailored nanopills, for sustained drug release in advanced cell therapies.

  9. Diagnostics Systems for Permanent Hall Thrusters Development

    NASA Astrophysics Data System (ADS)

    Ferreira, Jose Leonardo; Soares Ferreira, Ivan; Santos, Jean; Miranda, Rodrigo; Possa, M. Gabriela

    -Effect Thruster (PMHET), developed at the Plasma Physics Laboratory of UnB. The idea of using an array of permanent magnets, instead of an electromagnet, to produce a radial magnetic field inside the cylindrical plasma drift channel of the thruster is very attractive, especially because of the possibility of developing a HET with power consumption low enough to be used in small satellites or medium-size satellites with low on board power. Hall-Effect Thrusters are now a very good option for spacecraft primary propulsion and also for station-keeping of medium and large satellites. This is because of their high specific impulse, efficient use of propellant mass and combined low and precise thrust capabilities, which are related to an economy in terms of propellant mass utilization , longer satellite lifetime and easier spacecraft maneuvering in microgravity environment. The first HETs were developed in the mid 1950’s, and they were first called Closed Drift Thrusters. Today, the successful use of electric thrusters for attitude control and orbit modification on hundreds of satellites shows the advanced stage of development of this technology. In addition to this, after the success of space missions such as Deep Space One and Dawn (NASA), Hayabusa (JAXA) and Smart-1 (ESA), the employment of electric thrusters is also consolidated for the primary propulsion of spacecraft. This success is mainly due to three factors: reliability of this technology; efficiency of propellant utilization, and therefore reduction of the initial mass of the ship; possibility of operation over long time intervals, with practically unlimited cycling and restarts. This thrusting system is designed to be used in satellite attitude control and long term space missions. One of the greatest advantage of this kind of thruster is the production of a steady state magnetic field by permanent magnets providing electron trapping and Hall current generation within a significant decrease on the electric energy supply

  10. Advanced alternate planar geometry solid oxide fuel cells

    SciTech Connect

    Prouse, D.; Elangovan, S.; Khandkar, A. ); Donelson, R.; Marianowski, L. )

    1988-01-01

    The following Ceramatec tasks are reported: electrolyte development and fabrication, edge seal development/fabrication, electrode, and interconnector. The following IGT tasks are reported: cell design analysis, and program liaison and test facility preparation.

  11. Recent Advances in Hydroxyapatite Scaffolds Containing Mesenchymal Stem Cells

    PubMed Central

    Michel, John; Penna, Matthew; Kochen, Juan; Cheung, Herman

    2015-01-01

    Modern day tissue engineering and cellular therapies have gravitated toward using stem cells with scaffolds as a dynamic modality to aid in differentiation and tissue regeneration. Mesenchymal stem cells (MSCs) are one of the most studied stem cells used in combination with scaffolds. These cells differentiate along the osteogenic lineage when seeded on hydroxyapatite containing scaffolds and can be used as a therapeutic option to regenerate various tissues. In recent years, the combination of hydroxyapatite and natural or synthetic polymers has been studied extensively. Due to the interest in these scaffolds, this review will cover the wide range of hydroxyapatite containing scaffolds used with MSCs for in vitro and in vivo experiments. Further, in order to maintain a progressive scope of the field this review article will only focus on literature utilizing adult human derived MSCs (hMSCs) published in the last three years. PMID:26106425

  12. Further advances in silicon solar cell technology for space application

    NASA Technical Reports Server (NTRS)

    Lillington, D. R.; Kukulka, J. R.

    1986-01-01

    Recent improvements relating to the design of high efficiency cells are presented. A conceptual design using passivation techniques is discussed, which potentially increases the open circuit voltage to approximately 650 mV. This concept is supported by experimental data using only silicon passivation beneath contacts. The use of thin thermal oxides of silicon for passivation between contacts is also discussed. A number of novel structures have also been fabricated to investigate reduction in the thermal alpha of planar and sculptured cells. It is shown that this may be as low as 0.63 on glassed gridded back cells, and that the IR rejection beyond 1.1 microns may approach 100 percent if the backside is AR coated. Finally, experimental data is given to support the existence of free electron absorption in heavily doped emitters on sculptured cells.

  13. Induced Pluripotent Stem Cells in Dermatology: Potentials, Advances, and Limitations

    PubMed Central

    Bilousova, Ganna; Roop, Dennis R.

    2015-01-01

    The discovery of methods for reprogramming adult somatic cells into induced pluripotent stem cells (iPSCs) has raised the possibility of producing truly personalized treatment options for numerous diseases. Similar to embryonic stem cells (ESCs), iPSCs can give rise to any cell type in the body and they are amenable to genetic correction by homologous recombination. These ESC properties of iPSCs allow for the development of permanent corrective therapies for many currently incurable disorders, including inherited skin diseases, without using embryonic tissues or oocytes. Here, we review recent progress and limitations of iPSC research with a focus on clinical applications of iPSCs, and using iPSCs to model human diseases for drug discovery in the field of dermatology. PMID:25368014

  14. Recent Advances in Carbon Nanotube-Based Enzymatic Fuel Cells

    PubMed Central

    Cosnier, Serge; Holzinger, Michael; Le Goff, Alan

    2014-01-01

    This review summarizes recent trends in the field of enzymatic fuel cells. Thanks to the high specificity of enzymes, biofuel cells can generate electrical energy by oxidation of a targeted fuel (sugars, alcohols, or hydrogen) at the anode and reduction of oxidants (O2, H2O2) at the cathode in complex media. The combination of carbon nanotubes (CNT), enzymes and redox mediators was widely exploited to develop biofuel cells since the electrons involved in the bio-electrocatalytic processes can be efficiently transferred from or to an external circuit. Original approaches to construct electron transfer based CNT-bioelectrodes and impressive biofuel cell performances are reported as well as biomedical applications. PMID:25386555

  15. Induced pluripotent stem cells in dermatology: potentials, advances, and limitations.

    PubMed

    Bilousova, Ganna; Roop, Dennis R

    2014-11-01

    The discovery of methods for reprogramming adult somatic cells into induced pluripotent stem cells (iPSCs) has raised the possibility of producing truly personalized treatment options for numerous diseases. Similar to embryonic stem cells (ESCs), iPSCs can give rise to any cell type in the body and are amenable to genetic correction by homologous recombination. These ESC properties of iPSCs allow for the development of permanent corrective therapies for many currently incurable disorders, including inherited skin diseases, without using embryonic tissues or oocytes. Here, we review recent progress and limitations of iPSC research with a focus on clinical applications of iPSCs and using iPSCs to model human diseases for drug discovery in the field of dermatology.

  16. Recent Advances in Hydroxyapatite Scaffolds Containing Mesenchymal Stem Cells.

    PubMed

    Michel, John; Penna, Matthew; Kochen, Juan; Cheung, Herman

    2015-01-01

    Modern day tissue engineering and cellular therapies have gravitated toward using stem cells with scaffolds as a dynamic modality to aid in differentiation and tissue regeneration. Mesenchymal stem cells (MSCs) are one of the most studied stem cells used in combination with scaffolds. These cells differentiate along the osteogenic lineage when seeded on hydroxyapatite containing scaffolds and can be used as a therapeutic option to regenerate various tissues. In recent years, the combination of hydroxyapatite and natural or synthetic polymers has been studied extensively. Due to the interest in these scaffolds, this review will cover the wide range of hydroxyapatite containing scaffolds used with MSCs for in vitro and in vivo experiments. Further, in order to maintain a progressive scope of the field this review article will only focus on literature utilizing adult human derived MSCs (hMSCs) published in the last three years.

  17. Advances in Isolation Methods for Spermatogonial Stem Cells.

    PubMed

    Zhang, Rui; Sun, Jin; Zou, Kang

    2016-02-01

    Stem cell research has led to many remarkable achievements in recent years, but progress in the study of spermatogonial stem cells (SSCs) has been relatively slow, partly due to the slow development of techniques for spermatogonial stem cell isolation. The major accomplishments of SSC sorting and identification occurred approximately 10 years ago, and since that time, these techniques have been widely used without major improvements. In this article, we briefly introduce the biological properties of SSCs before reviewing the development of sorting techniques for SSCs in the past decades. We then summarize recent achievements in SSC sorting and finally discuss the advantages and disadvantages of SSC isolation methods, to provide new insight into techniques and research related to spermatogonial stem cells and promote the development of reproductive biology.

  18. Recent advances in the management of renal cell carcinoma

    PubMed Central

    Molina, Ana M.; Nanus, David M.

    2016-01-01

    Therapeutic options for patients with metastatic renal cell carcinoma have significantly improved over the past few years with the recent approval of two new agents resulting in prolonged progression-free and overall survival. PMID:27019698

  19. Advances and Applications of Single Cell Sequencing Technologies

    PubMed Central

    Wang, Yong; Navin, Nicholas E.

    2015-01-01

    Single cell sequencing (SCS) has emerged as a powerful new set of technologies for studying rare cells and delineating complex populations. Over the past 5 years, SCS methods for DNA and RNA have had a broad impact on many diverse fields of biology, including microbiology, neurobiology, development, tissue mosaicism, immunology and cancer research. In this review, we will discuss SCS technologies and applications, as well as translational applications in the clinic. PMID:26000845

  20. Spontaneous regression in advanced squamous cell lung carcinoma

    PubMed Central

    Park, Yeon Hee; Park, Bo Mi; Park, Se Yeon; Choi, Jae Woo; Kim, Sun Young; Kim, Ju Ock; Jung, Sung Soo; Park, Hee Sun; Moon, Jae Young

    2016-01-01

    Spontaneous regression of malignant tumors is rare especially of lung tumor and biological mechanism of such remission has not been addressed. We report the case of a 79-year-old Korean patient with non-small cell lung cancer, squamous cell cancer with a right hilar tumor and multiple lymph nodes, lung to lung metastasis that spontaneously regressed without any therapies. He has sustained partial remission state for one year and eight months after the first histological diagnosis. PMID:27076978

  1. Electrochemistry of the Hall-Heroult Process for Aluminum Smelting.

    ERIC Educational Resources Information Center

    Haupin, W. E.

    1983-01-01

    Nearly all aluminum is produced by the electrolysis of alumina dissolved in a molten cryolite-based electrolyte, the Hall-Heroult Process. Various aspects of the procedure are discussed, focusing on electrolyte chemistry, dissolution of alumina, electrode reactions, current efficiency, and cell voltage. Suggestions for graduate study related to…

  2. Spin Hall controlled magnonic microwaveguides

    SciTech Connect

    Demidov, V. E.; Urazhdin, S.; Rinkevich, A. B.; Reiss, G.; Demokritov, S. O.

    2014-04-14

    We use space-resolved magneto-optical spectroscopy to study the influence of spin Hall effect on the excitation and propagation of spin waves in microscopic magnonic waveguides. We find that the spin Hall effect not only increases the spin-wave propagation length, but also results in an increased excitation efficiency due to the increase of the dynamic susceptibility in the vicinity of the inductive antenna. We show that the efficiency of the propagation length enhancement is strongly dependant on the type of the excited spin-wave mode and its wavelength.

  3. Generalized quantum Hall projection Hamiltonians

    NASA Astrophysics Data System (ADS)

    Simon, Steven H.; Rezayi, E. H.; Cooper, Nigel R.

    2007-02-01

    Certain well known quantum Hall states—including the Laughlin states, the Moore-Read Pfaffian, and the Read-Rezayi Parafermion states—can be defined as the unique lowest degree symmetric analytic function that vanishes as at least p powers as some number (g+1) of particles approach the same point. Analogously, these same quantum Hall states can be generated as the exact highest density zero energy state of simple angular momentum projection operators. Following this theme we determine the highest density zero energy state for many other values of p and g .

  4. Evaluation of critical materials in five additional advance design photovoltaic cells

    SciTech Connect

    Smith, S.A.; Watts, R.L.; Martin, P.; Gurwell, W.E.

    1981-02-01

    The objective of this study is to identify potential material supply constraints due to the large-scale deployment of five advanced photovoltaic (PV) cell designs, and to suggest strategies to reduce the impacts of these production capacity limitations and potential future material shortages. The Critical Materials Assessment Program (CMAP) screens the designs and their supply chains and identifies potential shortages which might preclude large-scale use of the technologies. The results of the screening of five advanced PV cell designs are presented: (1) indium phosphide/cadmium sulfide, (2) zinc phosphide, (3) cadmium telluride/cadmium sulfide, (4) copper indium selenium, and (5) cadmium selenide photoelectrochemical. Each of these five cells is screened individually assuming that they first come online in 1991, and that 25 Gwe of peak capacity is online by the year 2000. A second computer screening assumes that each cell first comes online in 1991 and that each cell has a 5 GWe of peak capacity by the year 2000, so that the total online capacity for the five cells is 25 GWe. Based on a review of the preliminary baseline screening results, suggestions were made for varying such parameters as the layer thickness, cell production processes, etc. The resulting PV cell characterizations were then screened again by the CMAP computer code. The CMAP methodology used to identify critical materials is described; and detailed characterizations of the advanced photovoltaic cell designs under investigation, descriptions of additional cell production processes, and the results are presented. (WHK)

  5. μHall chip for sensitive detection of bacteria.

    PubMed

    Issadore, David; Chung, Hyun Jung; Chung, Jaehoon; Budin, Ghyslain; Weissleder, Ralph; Lee, Hakho

    2013-09-01

    Sensitive, rapid and phenotype-specific enumeration of pathogens is essential for the diagnosis of infectious disease, monitoring of food chains, and for defense against bioterrorism. Microbiological culture and genotyping, techniques that sensitively and selectively detect bacteria in laboratory settings, have limited application in clinical environments due to high cost, slow response times, and the need for specially trained staff and laboratory infrastructure. To address these challenges, we developed a microfluidic chip-based micro-HallHall) platform capable of measuring single, magnetically tagged bacteria directly in clinical specimens with minimal sample processing. We demonstrated the clinical utility of the μHall chip by enumerating Gram-positive bacteria. The overall detection limit of the system was similar to that of culture tests (~10 bacteria), but the assay time was 50-times faster. This low-cost, single-cell analytical technique is especially well-suited to diagnose infectious diseases in resource-limited clinical settings.

  6. [Technological advances in single-cell genomic analyses].

    PubMed

    Pan, Xing-Hua; Zhu, Hai-Ying; Marjani, Sadie L

    2011-01-01

    The technological progress of the genomics has transformed life science research. The main objectives of genomics are sequencing of new genomes and genome-wide identification of the function and the interaction of genes and their products. The recently developed second generation or next generation sequencing platforms and DNA microarray technology are immensely important and powerful tools for functional genomic analyses. However, their application is limited by the requirement of sufficient amounts of high quality nucleic acid samples. Therefore, when only a single cell or a very small number of cells are available or are preferred, the whole genomic sequencing or functional genomic objectives cannot be achieved conventionally and require a robust amplification method. This review highlights DNA amplification technologies and summarizes the strategies currently utilized for whole genome sequencing of a single cell, with specific focus on studies investigating microorganisms; An outline for targeted re-sequencing enabling the analysis of larger genomes is also provided. Furthermore, the review presents the emerging functional genomic applications using next-generation sequencing or microarray analysis to examine genome-wide transcriptional profile, chromatin modification and other types of protein-DNA binding profile, and CpG methylation mapping in a single cell or a very low quantity of cells. The nature of these technologies and their prospects are also addressed.

  7. Advances and perspectives of colorectal cancer stem cell vaccine.

    PubMed

    Guo, Mei; Dou, Jun

    2015-12-01

    Colorectal cancer is essentially an environmental and genetic disease featured by uncontrolled cell growth and the capability to invade other parts of the body by forming metastases, which inconvertibly cause great damage to tissues and organs. It has become one of the leading causes of cancer-related mortality in the developed countries such as United States, and approximately 1.2 million new cases are yearly diagnosed worldwide, with the death rate of more than 600,000 annually and incidence rates are increasing in most developing countries. Apart from the generally accepted theory that pathogenesis of colorectal cancer consists of genetic mutation of a certain target cell and diversifications in tumor microenvironment, the colorectal cancer stem cells (CCSCs) theory makes a different explanation, stating that among millions of colon cancer cells there is a specific and scanty cellular population which possess the capability of self-renewal, differentiation and strong oncogenicity, and is tightly responsible for drug resistance and tumor metastasis. Based on these characteristics, CCSCs are becoming a novel target cells both in the clinical and the basic studies, especially the study of CCSCs vaccines due to induced efficient immune response against CCSCs. This review provides an overview of CCSCs and preparation technics and targeting factors related to CCSCs vaccines in detail.

  8. Interspecies Somatic Cell Nuclear Transfer: Advancements and Problems

    PubMed Central

    Lagutina, Irina; Fulka, Helena; Lazzari, Giovanna

    2013-01-01

    Abstract Embryologists working with livestock species were the pioneers in the field of reprogramming by somatic cell nuclear transfer (SCNT). Without the “Dolly experiment,” the field of cellular reprogramming would have been slow and induced plutipotent cells (iPSCs) would not have been conceived. The major drive of the work in mammalian cloning was the interest of the breeding industry to propagate superior genotypes. Soon it was realized that the properties of oocytes could be used also to clone endangered mammalian species or to reprogram the genomes of unrelated species through what is known as interspecies (i) SCNT, using easily available oocytes of livestock species. iSCNT for cloning animals works only for species that can interbreed, and experiments with taxonomically distant species have not been successful in obtaining live births or deriving embryonic stem cell (ESC) lines to be used for regenerative medicine. There are controversial reports in the literature, but in most cases these experiments have underlined some of the cellular and molecular mechanisms that are incomplete during cell nucleus reprogramming, including the failure to organize nucleoli, silence somatic cell genes, activate the embryonic genome, and resume mitochondrial replication and function, thus indicating nucleus–cytoplasmic incompatibility. PMID:24033141

  9. Advanced PEFC development for fuel cell powered vehicles

    NASA Astrophysics Data System (ADS)

    Kawatsu, Shigeyuki

    Vehicles equipped with fuel cells have been developed with much progress. Outcomes of such development efforts include a Toyota fuel cell electric vehicle (FCEV) using hydrogen as the fuel which was developed and introduced in 1996, followed by another Toyota FCEV using methanol as the fuel, developed and introduced in 1997. In those Toyota FCEVs, a fuel cell system is installed under the floor of each RAV4L, to sports utility vehicle. It has been found that the CO concentration in the reformed gas of methanol reformer can be reduced to 100 ppm in wide ranges of catalyst temperature and gas flow rate, by using the ruthenium (Ru) catalyst as the CO selective oxidizer, instead of the platinum (Pt) catalyst known from some time ago. It has been also found that a fuel cell performance equivalent to that with pure hydrogen can be ensured even in the reformed gas with the carbon monoxide (CO) concentration of 100 ppm, by using the Pt-Ru (platinum ruthenium alloy) electrocatalyst as the anode electrocatalyst of a polymer electrolyte fuel cell (PEFC), instead of the Pt electrocatalyst known from some time ago.

  10. Corneal stem cells and tissue engineering: Current advances and future perspectives.

    PubMed

    de Araujo, Aline Lütz; Gomes, José Álvaro Pereira

    2015-06-26

    Major advances are currently being made in regenerative medicine for cornea. Stem cell-based therapies represent a novel strategy that may substitute conventional corneal transplantation, albeit there are many challenges ahead given the singularities of each cellular layer of the cornea. This review recapitulates the current data on corneal epithelial stem cells, corneal stromal stem cells and corneal endothelial cell progenitors. Corneal limbal autografts containing epithelial stem cells have been transplanted in humans for more than 20 years with great successful rates, and researchers now focus on ex vivo cultures and other cell lineages to transplant to the ocular surface. A small population of cells in the corneal endothelium was recently reported to have self-renewal capacity, although they do not proliferate in vivo. Two main obstacles have hindered endothelial cell transplantation to date: culture protocols and cell delivery methods to the posterior cornea in vivo. Human corneal stromal stem cells have been identified shortly after the recognition of precursors of endothelial cells. Stromal stem cells may have the potential to provide a direct cell-based therapeutic approach when injected to corneal scars. Furthermore, they exhibit the ability to deposit organized connective tissue in vitro and may be useful in corneal stroma engineering in the future. Recent advances and future perspectives in the field are discussed.

  11. Recent advancements in low cost solar cell processing

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.

    1975-01-01

    A proof-of-concept solar cell process has been developed that is adaptable to automation. This involved the development of a new contact system, a new antireflection coating system, a drift field cell design and a new contoured surface treatment. All these processes are performed without the use of vacuum chambers and expensive masking techniques, thus providing the possibility of reduced costs by automation using conventional semiconductor processing machinery. The contacts were printed on the cells by conventional silk screen machinery. The P(+) back field was formed by diffusing in aluminum from a printed aluminum back contact. The antireflection coating was formed by spinning on and baking a TiO2-SiO2 glass film. Air-mass-zero efficiencies of over 10% were achieved using this completely vacuum-free process.

  12. Advanced water-cooled phosphoric acid fuel cell development

    SciTech Connect

    Not Available

    1989-01-01

    Fabrication of repeat parts for small area short stack is underway: 100 electrode substrates and 150 ERP substrates were graphitized, and 30 electrode substrates were run through each manufacturing step. Teflon content and compaction pressure of shop-made electrodes for the small area short stack was optimized based on single cell tests. A single cell with GSB-18P catalyst and 1 mg/cm[sup 2] loading is performing very well; performance is 0.66 V per cell after 1200 h at 300 ASF. 3 integral separator plate configurations have been selected for verification in the upcoming short stack. Bubble pressures over 7 psid have been demonstrated in filler bands applied with a production curtain and coating process. 5 full-size (small area) coolers were molded, and encapsulation development for molded and commercial graphite coolers continued.

  13. The Other Hall Effect: College Board Physics

    ERIC Educational Resources Information Center

    Sheppard, Keith; Gunning, Amanda M.

    2013-01-01

    Edwin Herbert Hall (1855-1938), discoverer of the Hall effect, was one of the first winners of the AAPT Oersted Medal for his contributions to the teaching of physics. While Hall's role in establishing laboratory work in high schools is widely acknowledged, his position as chair of the physics section of the Committee on College Entrance…

  14. Advanced XAS Analysis for Investigating Fuel Cell Electrocatalysts

    SciTech Connect

    Witkowska, Agnieszka; Principi, Emiliano; Di Cicco, Andrea; Marassi, Roberto

    2007-02-02

    In the paper we present an accurate structural study of a Pt-based electrode by means of XAS, accounting for both the catalytic nanoparticles size distribution and sample inhomogeneities. Morphology and size distribution of the nanoparticles were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction techniques. XAS data-analysis was performed using advanced multiple-scattering techniques (GNXAS), disentangling possible effects due to surface atom contributions in nanoparticles and sample homogeneity, contributing to a reduction of intensity of the structural signal. This approach for XAS investigation of electrodes of FC devices can represent a viable and reliable way to understand structural details, important for producing more efficient catalytic materials.

  15. Advanced Water-Cooled Phosphoric Acid Fuel Cell Development

    SciTech Connect

    Not Available

    1988-01-01

    The initial conceptual design configuration was completed. Baseline on-site electrodes were tested at electric utility conditions in 2 x 2 inch cells. GSB-18P cathodes were fabricated. Design of small area development stack was initiated and long lead time items ordered. Molded cooler thermal cycling tests were initiated. Equipment to evaluate alternative manifold coating processes and materials were procured.

  16. Advanced water-cooled phosphoric acid fuel cell development

    SciTech Connect

    Not Available

    1992-09-01

    This program was conducted to improve the performance and minimize the cost of existing water-cooled phosphoric acid fuel cell stacks for electric utility and on-site applications. The goals for the electric utility stack technology were a power density of at least 175 watts per square foot over a 40,000-hour useful life and a projected one-of-a-kind, full-scale manufactured cost of less than $400 per kilowatt. The program adapted the existing on-site Configuration-B cell design to electric utility operating conditions and introduced additional new design features. Task 1 consisted of the conceptual design of a full-scale electric utility cell stack that meets program objectives. The conceptual design was updated to incorporate the results of material and process developments in Tasks 2 and 3, as well as results of stack tests conducted in Task 6. Tasks 2 and 3 developed the materials and processes required to fabricate the components that meet the program objectives. The design of the small area and 10-ft{sup 2} stacks was conducted in Task 4. Fabrication and assembly of the short stacks were conducted in Task 5 and subsequent tests were conducted in Task 6. The management and reporting functions of Task 7 provided DOE/METC with program visibility through required documentation and program reviews. This report describes the cell design and development effort that was conducted to demonstrate, by subscale stack test, the technical achievements made toward the above program objectives.

  17. Magnum(R) NiCd advanced nickel-cadmium battery cells

    NASA Technical Reports Server (NTRS)

    Scoles, Darren

    1995-01-01

    The Power Systems Department of Eagle-Picher Industries, Inc., located in Colorado Springs, Colorado, had developed a long-life advanced Nickel-Cadmium battery cell for aerospace applications. This battery cell, known as the MAGNUM NiCd cell, offers significant life expectancy increase over traditional NiCd battery cells. In addition, it offers significant cost reduction from the Super NiCd battery cell (developed by Hughes Aircraft Company and manufactured by the Power Systems Department of Eagle-Picher Industries, Inc.).

  18. Development of processing procedures for advanced silicon solar cells. [antireflection coatings and short circuit currents

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Stella, P. M.; Avery, J. E.

    1975-01-01

    Ten ohm-cm silicon solar cells, 0.2 mm thick, were produced with short circuit current efficiencies up to thirteen percent and using a combination of recent technical advances. The cells were fabricated in conventional and wraparound contact configurations. Improvement in cell collection efficiency from both the short and long wavelengths region of the solar spectrum was obtained by coupling a shallow junction and an optically transparent antireflection coating with back surface field technology. Both boron diffusion and aluminum alloying techniques were evaluated for forming back surface field cells. The latter method is less complicated and is compatible with wraparound cell processing.

  19. Advances in Induced Pluripotent Stem Cells, Genomics, Biomarkers, and Antiplatelet Therapy

    PubMed Central

    Barbato, Emanuele; Lara-Pezzi, Enrique; Stolen, Craig; Taylor, Angela; Barton, Paul J.; Bartunek, Jozef; Iaizzo, Paul; Judge, Daniel P.; Kirshenbaum, Lorrie; Blaxall, Burns C.; Terzic, Andre; Hall, Jennifer L.

    2014-01-01

    The Journal provides the clinician and scientist with the latest advances in discovery research, emerging technologies, pre-clinical research design and testing, and clinical trials. We highlight advances in areas of induced pluripotent stem cells, genomics, biomarkers, multi-modality imaging and antiplatelet biology and therapy. The top publications are critically discussed and presented along with anatomical reviews and FDA insight to provide context. PMID:24659088

  20. Atlanta's Own "Hall" of Famer

    ERIC Educational Resources Information Center

    Maxwell, Lesil A.

    2008-01-01

    This article features Beverly L. Hall, poised to become one of the longest-serving superintendents of the Atlanta schools. When she came to Atlanta in 1999, student achievement was sliding downward, teacher morale was dismal, and enrollment was falling as parents pulled their children out of the school system. Under the superintendent's driving…

  1. Annual Report: Advanced Energy Systems Fuel Cells (30 September 2013)

    SciTech Connect

    Gerdes, Kirk; Richards, George

    2014-04-16

    The comprehensive research plan for Fuel Cells focused on Solid State Energy Conversion Alliance (SECA) programmatic targets and included objectives in two primary and focused areas: (1) investigation of degradation modes exhibited by the anode/electrolyte/cathode (AEC), development of computational models describing the associated degradation rates, and generation of a modeling tool predicting long term AEC degradation response; and (2) generation of novel electrode materials and microstructures and implementation of the improved electrode technology to enhance performance. In these areas, the National Energy Technology Laboratory (NETL) Regional University Alliance (RUA) team has completed and reported research that is significant to the SECA program, and SECA continued to engage all SECA core and SECA industry teams. Examination of degradation in an operational solid oxide fuel cell (SOFC) requires a logical organization of research effort into activities such as fundamental data gathering, tool development, theoretical framework construction, computational modeling, and experimental data collection and validation. Discrete research activity in each of these categories was completed throughout the year and documented in quarterly reports, and researchers established a framework to assemble component research activities into a single operational modeling tool. The modeling framework describes a scheme for categorizing the component processes affecting the temporal evolution of cell performance, and provides a taxonomical structure of known degradation processes. The framework is an organizational tool that can be populated by existing studies, new research completed in conjunction with SECA, or independently obtained. The Fuel Cell Team also leveraged multiple tools to create cell performance and degradation predictions that illustrate the combined utility of the discrete modeling activity. Researchers first generated 800 continuous hours of SOFC experimental

  2. Advances in simulation study on organic small molecular solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; Guo, Wenge; Li, Ming; Ma, Wentao; Meng, Sen

    2015-02-01

    Recently, more focuses have been put on organic semiconductors because of its advantages, such as its flexibility, ease of fabrication and potential low cost, etc. The reasons we pay highlight on small molecular photovoltaic material are its ease of purification, easy to adjust and determine structure, easy to assemble range units and get high carrier mobility, etc. Simulation study on organic small molecular solar cells before the experiment can help the researchers find relationship between the efficiency and structure parameters, properties of material, estimate the performance of the device, bring the optimization of guidance. Also, the applicability of the model used in simulation can be discussed by comparison with experimental data. This paper summaries principle, structure, progress of numerical simulation on organic small molecular solar cells.

  3. Advances in T-cell therapy for ALL

    PubMed Central

    Grupp, Stephan A.

    2014-01-01

    CD19-directed chimeric antigen receptor T cells (CART19 or CTL019) have been used with success in pediatric and adult acute lymphocytic leukemia (ALL) and chronic lymphocytic leukemia (CLL) patients. While this therapy has caused toxicities, including cytokine release syndrome and macrophage activation syndrome, these conditions are reversible with IL-6 blockade using the monoclonal antibody tocilizumab. Furthermore, 90% of the very high-risk patients who underwent infusion with CTL019 achieved a complete response, despite the fact that they previously failed multiple therapies and/or transplant. With improved cell persistence, this immunotherapy may one day prove to be more than a bridge to transplant and may in fact be a transplant alternative. PMID:25455270

  4. Advancing cell biology through proteomics in space and time (PROSPECTS).

    PubMed

    Lamond, Angus I; Uhlen, Mathias; Horning, Stevan; Makarov, Alexander; Robinson, Carol V; Serrano, Luis; Hartl, F Ulrich; Baumeister, Wolfgang; Werenskiold, Anne Katrin; Andersen, Jens S; Vorm, Ole; Linial, Michal; Aebersold, Ruedi; Mann, Matthias

    2012-03-01

    The term "proteomics" encompasses the large-scale detection and analysis of proteins and their post-translational modifications. Driven by major improvements in mass spectrometric instrumentation, methodology, and data analysis, the proteomics field has burgeoned in recent years. It now provides a range of sensitive and quantitative approaches for measuring protein structures and dynamics that promise to revolutionize our understanding of cell biology and molecular mechanisms in both human cells and model organisms. The Proteomics Specification in Time and Space (PROSPECTS) Network is a unique EU-funded project that brings together leading European research groups, spanning from instrumentation to biomedicine, in a collaborative five year initiative to develop new methods and applications for the functional analysis of cellular proteins. This special issue of Molecular and Cellular Proteomics presents 16 research papers reporting major recent progress by the PROSPECTS groups, including improvements to the resolution and sensitivity of the Orbitrap family of mass spectrometers, systematic detection of proteins using highly characterized antibody collections, and new methods for absolute as well as relative quantification of protein levels. Manuscripts in this issue exemplify approaches for performing quantitative measurements of cell proteomes and for studying their dynamic responses to perturbation, both during normal cellular responses and in disease mechanisms. Here we present a perspective on how the proteomics field is moving beyond simply identifying proteins with high sensitivity toward providing a powerful and versatile set of assay systems for characterizing proteome dynamics and thereby creating a new "third generation" proteomics strategy that offers an indispensible tool for cell biology and molecular medicine.

  5. Targeted treatments in advanced renal cell carcinoma: focus on axitinib

    PubMed Central

    Verzoni, Elena; Grassi, Paolo; Testa, Isabella; Iacovelli, Roberto; Biondani, Pamela; Garanzini, Enrico; De Braud, Filippo; Procopio, Giuseppe

    2014-01-01

    Antiangiogenesis options have evolved rapidly in the last few years, with an increasing number of agents currently approved by the US Food and Drug Administration and European Medicines Agency. Angiogenesis inhibitors have been shown to be very effective for the treatment of metastatic renal cancer cell. Axitinib is a third-generation inhibitor of vascular endothelial growth factor receptor and is currently being developed for the treatment of various malignancies. The pharmacokinetic properties of axitinib may have a selective therapeutic effect, with minimal adverse reactions and enhanced safety. In a large Phase III study of previously treated patients with metastatic renal cell carcinoma, axitinib achieved a longer progression-free survival than sorafenib with an acceptable safety profile and good quality of life. This review focuses on the pharmacology, pharmacokinetics, and clinical activity of axitinib in the current treatment of renal cell carcinoma. The role of axitinib in the adjuvant and/or neoadjuvant setting needs to be evaluated in further clinical trials. PMID:24715765

  6. Thermal management of advanced fuel cell power systems

    NASA Technical Reports Server (NTRS)

    Vanderborgh, N. E.; Hedstrom, J.; Huff, J.

    1990-01-01

    It is shown that fuel cell devices are particularly attractive for the high-efficiency, high-reliability space hardware necessary to support upcoming space missions. These low-temperature hydrogen-oxygen systems necessarily operate with two-phase water. In either PEMFCs (proton exchange membrane fuel cells) or AFCs (alkaline fuel cells), engineering design must be critically focused on both stack temperature control and on the relative humidity control necessary to sustain appropriate conductivity within the ionic conductor. Water must also be removed promptly from the hardware. Present designs for AFC space hardware accomplish thermal management through two coupled cooling loops, both driven by a heat transfer fluid, and involve a recirculation fan to remove water and heat from the stack. There appears to be a certain advantage in using product water for these purposes within PEM hardware, because in that case a single fluid can serve both to control stack temperature, operating simultaneously as a heat transfer medium and through evaporation, and to provide the gas-phase moisture levels necessary to set the ionic conductor at appropriate performance levels. Moreover, the humidification cooling process automatically follows current loads. This design may remove the necessity for recirculation gas fans, thus demonstrating the long-term reliability essential for future space power hardware.

  7. Glioblastoma cancer stem cells: Biomarker and therapeutic advances.

    PubMed

    Pointer, Kelli B; Clark, Paul A; Zorniak, Michael; Alrfaei, Bahauddeen M; Kuo, John S

    2014-05-01

    Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in humans. It accounts for fifty-two percent of primary brain malignancies in the United States and twenty percent of all primary intracranial tumors. Despite the current standard therapies of maximal safe surgical resection followed by temozolomide and radiotherapy, the median patient survival is still less than 2 years due to inevitable tumor recurrence. Glioblastoma cancer stem cells (GSCs) are a subgroup of tumor cells that are radiation and chemotherapy resistant and likely contribute to rapid tumor recurrence. In order to gain a better understanding of the many GBM-associated mutations, analysis of the GBM cancer genome is on-going; however, innovative strategies to target GSCs and overcome tumor resistance are needed to improve patient survival. Cancer stem cell biology studies reveal basic understandings of GSC resistance patterns and therapeutic responses. Membrane proteomics using phage and yeast display libraries provides a method to identify novel antibodies and surface antigens to better recognize, isolate, and target GSCs. Altogether, basic GBM and GSC genetics and proteomics studies combined with strategies to discover GSC-targeting agents could lead to novel treatments that significantly improve patient survival and quality of life.

  8. Recent Advances in Disease Modeling and Drug Discovery for Diabetes Mellitus Using Induced Pluripotent Stem Cells.

    PubMed

    Kawser Hossain, Mohammed; Abdal Dayem, Ahmed; Han, Jihae; Kumar Saha, Subbroto; Yang, Gwang-Mo; Choi, Hye Yeon; Cho, Ssang-Goo

    2016-01-01

    Diabetes mellitus (DM) is a widespread metabolic disease with a progressive incidence of morbidity and mortality worldwide. Despite extensive research, treatment options for diabetic patients remains limited. Although significant challenges remain, induced pluripotent stem cells (iPSCs) have the capacity to differentiate into any cell type, including insulin-secreting pancreatic β cells, highlighting its potential as a treatment option for DM. Several iPSC lines have recently been derived from both diabetic and healthy donors. Using different reprogramming techniques, iPSCs were differentiated into insulin-secreting pancreatic βcells. Furthermore, diabetes patient-derived iPSCs (DiPSCs) are increasingly being used as a platform to perform cell-based drug screening in order to develop DiPSC-based cell therapies against DM. Toxicity and teratogenicity assays based on iPSC-derived cells can also provide additional information on safety before advancing drugs to clinical trials. In this review, we summarize recent advances in the development of techniques for differentiation of iPSCs or DiPSCs into insulin-secreting pancreatic β cells, their applications in drug screening, and their role in complementing and replacing animal testing in clinical use. Advances in iPSC technologies will provide new knowledge needed to develop patient-specific iPSC-based diabetic therapies. PMID:26907255

  9. Recent Advances in Disease Modeling and Drug Discovery for Diabetes Mellitus Using Induced Pluripotent Stem Cells

    PubMed Central

    Kawser Hossain, Mohammed; Abdal Dayem, Ahmed; Han, Jihae; Kumar Saha, Subbroto; Yang, Gwang-Mo; Choi, Hye Yeon; Cho, Ssang-Goo

    2016-01-01

    Diabetes mellitus (DM) is a widespread metabolic disease with a progressive incidence of morbidity and mortality worldwide. Despite extensive research, treatment options for diabetic patients remains limited. Although significant challenges remain, induced pluripotent stem cells (iPSCs) have the capacity to differentiate into any cell type, including insulin-secreting pancreatic β cells, highlighting its potential as a treatment option for DM. Several iPSC lines have recently been derived from both diabetic and healthy donors. Using different reprogramming techniques, iPSCs were differentiated into insulin-secreting pancreatic βcells. Furthermore, diabetes patient-derived iPSCs (DiPSCs) are increasingly being used as a platform to perform cell-based drug screening in order to develop DiPSC-based cell therapies against DM. Toxicity and teratogenicity assays based on iPSC-derived cells can also provide additional information on safety before advancing drugs to clinical trials. In this review, we summarize recent advances in the development of techniques for differentiation of iPSCs or DiPSCs into insulin-secreting pancreatic β cells, their applications in drug screening, and their role in complementing and replacing animal testing in clinical use. Advances in iPSC technologies will provide new knowledge needed to develop patient-specific iPSC-based diabetic therapies. PMID:26907255

  10. Recent Advances in Disease Modeling and Drug Discovery for Diabetes Mellitus Using Induced Pluripotent Stem Cells.

    PubMed

    Kawser Hossain, Mohammed; Abdal Dayem, Ahmed; Han, Jihae; Kumar Saha, Subbroto; Yang, Gwang-Mo; Choi, Hye Yeon; Cho, Ssang-Goo

    2016-01-01

    Diabetes mellitus (DM) is a widespread metabolic disease with a progressive incidence of morbidity and mortality worldwide. Despite extensive research, treatment options for diabetic patients remains limited. Although significant challenges remain, induced pluripotent stem cells (iPSCs) have the capacity to differentiate into any cell type, including insulin-secreting pancreatic β cells, highlighting its potential as a treatment option for DM. Several iPSC lines have recently been derived from both diabetic and healthy donors. Using different reprogramming techniques, iPSCs were differentiated into insulin-secreting pancreatic βcells. Furthermore, diabetes patient-derived iPSCs (DiPSCs) are increasingly being used as a platform to perform cell-based drug screening in order to develop DiPSC-based cell therapies against DM. Toxicity and teratogenicity assays based on iPSC-derived cells can also provide additional information on safety before advancing drugs to clinical trials. In this review, we summarize recent advances in the development of techniques for differentiation of iPSCs or DiPSCs into insulin-secreting pancreatic β cells, their applications in drug screening, and their role in complementing and replacing animal testing in clinical use. Advances in iPSC technologies will provide new knowledge needed to develop patient-specific iPSC-based diabetic therapies.

  11. Planar Hall effect bridge magnetic field sensors

    SciTech Connect

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-05

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  12. Planar Hall effect bridge magnetic field sensors

    NASA Astrophysics Data System (ADS)

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  13. The Other Hall Effect: College Board Physics

    NASA Astrophysics Data System (ADS)

    Sheppard, Keith; Gunning, Amanda M.

    2013-09-01

    Edwin Herbert Hall (1855-1938), discoverer of the Hall effect, was one of the first winners of the AAPT Oersted Medal for his contributions to the teaching of physics. While Hall's role in establishing laboratory work in high schools is widely acknowledged, his position as chair of the physics section of the Committee on College Entrance Requirements was contentious and his involvement in launching College Board Physics, what we call the "other Hall effect," has largely been overlooked. This article details Hall's role in the development of College Board Physics.

  14. Hedgehog pathway inhibition in advanced basal cell carcinoma: latest evidence and clinical usefulness.

    PubMed

    Silapunt, Sirunya; Chen, Leon; Migden, Michael R

    2016-09-01

    Treatment of locally advanced basal cell carcinomas (laBCCs) with large, aggressive, destructive, and disfiguring tumors, or metastatic disease is challenging. Dysregulation of the Hedgehog (Hh) signaling pathway has been identified in the vast majority of basal cell carcinomas (BCCs). There are two United States Food and Drug Administration (US FDA)-approved Hh pathway inhibitors (HPIs) that exhibit antitumor activity in advanced BCC with an acceptable safety profile. Common adverse effects include muscle spasms, dysgeusia, alopecia, fatigue, nausea and weight loss. PMID:27583029

  15. Hedgehog pathway inhibition in advanced basal cell carcinoma: latest evidence and clinical usefulness

    PubMed Central

    Silapunt, Sirunya; Chen, Leon; Migden, Michael R.

    2016-01-01

    Treatment of locally advanced basal cell carcinomas (laBCCs) with large, aggressive, destructive, and disfiguring tumors, or metastatic disease is challenging. Dysregulation of the Hedgehog (Hh) signaling pathway has been identified in the vast majority of basal cell carcinomas (BCCs). There are two United States Food and Drug Administration (US FDA)-approved Hh pathway inhibitors (HPIs) that exhibit antitumor activity in advanced BCC with an acceptable safety profile. Common adverse effects include muscle spasms, dysgeusia, alopecia, fatigue, nausea and weight loss. PMID:27583029

  16. Optical Hall effect-model description: tutorial.

    PubMed

    Schubert, Mathias; Kühne, Philipp; Darakchieva, Vanya; Hofmann, Tino

    2016-08-01

    The optical Hall effect is a physical phenomenon that describes the occurrence of magnetic-field-induced dielectric displacement at optical wavelengths, transverse and longitudinal to the incident electric field, and analogous to the static electrical Hall effect. The electrical Hall effect and certain cases of the optical Hall effect observations can be explained by extensions of the classic Drude model for the transport of electrons in metals. The optical Hall effect is most useful for characterization of electrical properties in semiconductors. Among many advantages, while the optical Hall effect dispenses with the need of electrical contacts, electrical material properties such as effective mass and mobility parameters, including their anisotropy as well as carrier type and density, can be determined from the optical Hall effect. Measurement of the optical Hall effect can be performed within the concept of generalized ellipsometry at an oblique angle of incidence. In this paper, we review and discuss physical model equations, which can be used to calculate the optical Hall effect in single- and multiple-layered structures of semiconductor materials. We define the optical Hall effect dielectric function tensor, demonstrate diagonalization approaches, and show requirements for the optical Hall effect tensor from energy conservation. We discuss both continuum and quantum approaches, and we provide a brief description of the generalized ellipsometry concept, the Mueller matrix calculus, and a 4×4 matrix algebra to calculate data accessible by experiment. In a follow-up paper, we will discuss strategies and approaches for experimental data acquisition and analysis.

  17. Optical Hall effect-model description: tutorial.

    PubMed

    Schubert, Mathias; Kühne, Philipp; Darakchieva, Vanya; Hofmann, Tino

    2016-08-01

    The optical Hall effect is a physical phenomenon that describes the occurrence of magnetic-field-induced dielectric displacement at optical wavelengths, transverse and longitudinal to the incident electric field, and analogous to the static electrical Hall effect. The electrical Hall effect and certain cases of the optical Hall effect observations can be explained by extensions of the classic Drude model for the transport of electrons in metals. The optical Hall effect is most useful for characterization of electrical properties in semiconductors. Among many advantages, while the optical Hall effect dispenses with the need of electrical contacts, electrical material properties such as effective mass and mobility parameters, including their anisotropy as well as carrier type and density, can be determined from the optical Hall effect. Measurement of the optical Hall effect can be performed within the concept of generalized ellipsometry at an oblique angle of incidence. In this paper, we review and discuss physical model equations, which can be used to calculate the optical Hall effect in single- and multiple-layered structures of semiconductor materials. We define the optical Hall effect dielectric function tensor, demonstrate diagonalization approaches, and show requirements for the optical Hall effect tensor from energy conservation. We discuss both continuum and quantum approaches, and we provide a brief description of the generalized ellipsometry concept, the Mueller matrix calculus, and a 4×4 matrix algebra to calculate data accessible by experiment. In a follow-up paper, we will discuss strategies and approaches for experimental data acquisition and analysis. PMID:27505654

  18. Electrocatalyst advances for hydrogen oxidation in phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Stonehart, P.

    1984-01-01

    The important considerations that presently exist for achieving commercial acceptance of fuel cells are centered on cost (which translates to efficiency) and lifetime. This paper addresses the questions of electrocatalyst utilization within porous electrode structures and the preparation of low-cost noble metal electrocatalyst combinations with extreme dispersions of the metal. Now that electrocatalyst particles can be prepared with dimensions of 10 A, either singly or in alloy combinations, a very large percentage of the noble metal atoms in a crystallite are available for reaction. The cost savings for such electrocatalysts in the present commercially driven environment are considerable.

  19. Advanced carbon anode materials for lithium ion cells

    NASA Astrophysics Data System (ADS)

    Azuma, Hideto; Imoto, Hiroshi; Yamada, Shin'ichiro; Sekai, Koji

    Three kinds of carbon have been used for commercial cells: graphite, soft carbon and hard carbon. The difference in the structures of these three kinds of carbon is shown clearly using our new model for soft and hard carbon structure. The lithium-doped state of these three kinds of carbon is discussed using the new structural model and published 7Li NMR data. A large reversible capacity is demonstrated in the hard carbons derived from some vegetable fibers. Two mechanisms—one enhancing the adsorbing force of pseudo-metallic lithium atoms and one reducing the repulsion force between doped lithium atoms—which together produce a high reversible capacity, are explained.

  20. Recent advances in redox flow cell storage systems

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1979-01-01

    Several features which were conceived and incorporated into complete redox systems that greatly enhanced its ability to be kept in proper charge balance, to be capable of internal voltage regulation, and in general be treated as a true multicell electrochemical system rather than an assembly of single cells that were wired together, were discussed. The technology status as it relates to the two application areas of solar photovoltaic/wind and distributed energy storage for electric utility applications was addressed. The cost and life advantages of redox systems were also covered.

  1. [Prostate cancer stem cells: advances in current research].

    PubMed

    Wu, Gang; Wu, Deng-long

    2015-02-01

    Prostate cancer is one of the most common malignancies threatening men's health, and the mechanisms underlying its initiation and progression are poorly understood. Last decade has witnessed encouraging progress in the studies of prostate cancer stem cells (PCSCs), which are considered to play important roles in tumor initiation, recurrence and metastasis, castration resistance, and drug resistance. Therefore, a deeper insight into PCSCs is of great significance for the successful management of prostate cancer. This article presents an overview on the location, origin, and markers of PCSCs as well as their potential correlation with tumor metastasis and castration resistance.

  2. Advances in radiation biology: Radiosensitization in DNA and living cells

    NASA Astrophysics Data System (ADS)

    Lacombe, S.; Sech, C. Le

    2009-06-01

    One fundamental goal of radiation biology is the evolution of concepts and methods for the elaboration of new approaches and protocols for the treatment of cancers. In this context, the use of fast ions as ionizing particles offers the advantage of optimizing cell killing inside the tumor whilst preserving the surrounding healthy tissues. One extremely promising strategy investigated recently is the addition of radiosensitizers in the targeted tissue. The optimization of radiotherapy with fast ions implies a multidisciplinary approach to ionizing radiation effects on complex living systems, ranging from studies on single molecules to investigations of entire organisms. In this article we review recent studies on ion induced damages in simple and complex biological systems, from DNA to living cells. The specific aspect of radiosensitization induced by metallic atoms is described. As a fundamental result, the addition of sensitizing compounds with ion irradiation may improve therapeutic index in cancer therapy. In conclusion, new perspectives are proposed based on the experience and contribution of different communities including Surface Sciences, to improve the development of radiation biology.

  3. Vascular endothelial platelet endothelial cell adhesion molecule 1 (PECAM-1) regulates advanced metastatic progression

    PubMed Central

    DeLisser, Horace; Liu, Yong; Desprez, Pierre-Yves; Thor, Ann; Briasouli, Paraskevei; Handumrongkul, Chakrapong; Wilfong, Jonathon; Yount, Garret; Nosrati, Mehdi; Fong, Sylvia; Shtivelman, Emma; Fehrenbach, Melane; Cao, Gaoyuan; Moore, Dan H.; Nayak, Shruti; Liggitt, Denny; Kashani-Sabet, Mohammed; Debs, Robert

    2010-01-01

    Most patients who die from cancer succumb to treatment-refractory advanced metastatic progression. Although the early stages of tumor metastasis result in the formation of clinically silent micrometastatic foci, its later stages primarily reflect the progressive, organ-destructive growth of already advanced metastases. Early-stage metastasis is regulated by multiple factors within tumor cells as well as by the tumor microenvironment (TME). In contrast, the molecular determinants that control advanced metastatic progression remain essentially uncharacterized, precluding the development of therapies targeted against it. Here we show that the TME, functioning in part through platelet endothelial cell adhesion molecule 1 (PECAM-1), drives advanced metastatic progression and is essential for progression through its preterminal end stage. PECAM-1–KO and chimeric mice revealed that its metastasis-promoting effects are mediated specifically through vascular endothelial cell (VEC) PECAM-1. Anti–PECAM-1 mAb therapy suppresses both end-stage metastatic progression and tumor-induced cachexia in tumor-bearing mice. It reduces proliferation, but not angiogenesis or apoptosis, within advanced tumor metastases. Because its antimetastatic effects are mediated by binding to VEC rather than to tumor cells, anti–PECAM-1 mAb appears to act independently of tumor type. A modified 3D coculture assay showed that anti–PECAM-1 mAb inhibits the proliferation of PECAM-1–negative tumor cells by altering the concentrations of secreted factors. Our studies indicate that a complex interplay between elements of the TME and advanced tumor metastases directs end-stage metastatic progression. They also suggest that some therapeutic interventions may target late-stage metastases specifically. mAb-based targeting of PECAM-1 represents a TME-targeted therapeutic approach that suppresses the end stages of metastatic progression, until now a refractory clinical entity. PMID:20926749

  4. Electrochemically Deposited Ceria Structures for Advanced Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Brown, Evan C.

    As the pursuit towards emissions reduction intensifies with growing interest and nascent technologies, solid oxide fuel cells (SOFCs) remain an illustrious candidate for achieving our goals. Despite myriad advantages, SOFCs are still too costly for widespread deployment, even as unprecedented materials developments have recently emerged. This suggests that, in addition to informed materials selection, the necessary power output--and, thereby, cost-savings--gains must come from the fuel cell architecture. The work presented in this manuscript primarily investigates cathodic electrochemical deposition (CELD) as a scalable micro-/nanoscale fabrication tool for engineering ceria-based components in a SOFC assembly. Also, polymer sphere lithography was utilized to deposit fully connected, yet fully porous anti-dot metal films on yttira-stabilized zirconia (YSZ) with specific and knowable geometries, useful for mechanistic studies. Particular attention was given to anode structures, for which anti-dot metal films on YSZ served as composite substrates for subsequent CELD of doped ceria. By tuning the applied potential, a wide range of microstructures from high surface area coatings to planar, thin films was possible. In addition, definitive deposition was shown to occur on the electronically insulating YSZ surfaces, producing quality YSZ|ceria interfaces. These CELD ceria deposits exhibited promising electrochemical activity, as probed by A.C. Impedance Spectroscopy. In an effort to extend its usefulness as a SOFC fabrication tool, the CELD of ceria directly onto common SOFC cathode materials without a metallic phase was developed, as well as templated deposition schemes producing ceria nanowires and inverse opals.

  5. Advanced Materials for PEM-Based Fuel Cell Systems

    SciTech Connect

    James E. McGrath

    2005-10-26

    Proton exchange membrane fuel cells (PEMFCs) are quickly becoming attractive alternative energy sources for transportation, stationary power, and small electronics due to the increasing cost and environmental hazards of traditional fossil fuels. Two main classes of PEMFCs include hydrogen/air or hydrogen/oxygen fuel cells and direct methanol fuel cells (DMFCs). The current benchmark membrane for both types of PEMFCs is Nafion, a perfluorinated sulfonated copolymer made by DuPont. Nafion copolymers exhibit good thermal and chemical stability, as well as very high proton conductivity under hydrated conditions at temperatures below 80 °C. However, application of these membranes is limited due to their high methanol permeability and loss of conductivity at high temperatures and low relative humidities. These deficiencies have led to the search for improved materials for proton exchange membranes. Potential PEMs should have good thermal, hydrolytic, and oxidative stability, high proton conductivity, selective permeability, and mechanical durability over long periods of time. Poly(arylene ether)s, polyimides, polybenzimidazoles, and polyphenylenes are among the most widely investigated candidates for PEMs. Poly(arylene ether)s are a promising class of proton exchange membranes due to their excellent thermal and chemical stability and high glass transition temperatures. High proton conductivity can be achieved through post-sulfonation of poly(arylene ether) materials, but this most often results in very high water sorption or even water solubility. Our research has shown that directly polymerized poly(arylene ether) copolymers show important advantages over traditional post-sulfonated systems and also address the concerns with Nafion membranes. These properties were evaluated and correlated with morphology, structure-property relationships, and

  6. Advanced Materials for PEM-Based Fuel Cell Systems

    SciTech Connect

    James E. McGrath; Donald G. Baird; Michael von Spakovsky

    2005-10-26

    Proton exchange membrane fuel cells (PEMFCs) are quickly becoming attractive alternative energy sources for transportation, stationary power, and small electronics due to the increasing cost and environmental hazards of traditional fossil fuels. Two main classes of PEMFCs include hydrogen/air or hydrogen/oxygen fuel cells and direct methanol fuel cells (DMFCs). The current benchmark membrane for both types of PEMFCs is Nafion, a perfluorinated sulfonated copolymer made by DuPont. Nafion copolymers exhibit good thermal and chemical stability, as well as very high proton conductivity under hydrated conditions at temperatures below 80 degrees C. However, application of these membranes is limited due to their high methanol permeability and loss of conductivity at high temperatures and low relative humidities. These deficiencies have led to the search for improved materials for proton exchange membranes. Potential PEMs should have good thermal, hydrolytic, and oxidative stability, high proton conductivity, selective permeability, and mechanical durability over long periods of time. Poly(arylene ether)s, polyimides, polybenzimidazoles, and polyphenylenes are among the most widely investigated candidates for PEMs. Poly(arylene ether)s are a promising class of proton exchange membranes due to their excellent thermal and chemical stability and high glass transition temperatures. High proton conductivity can be achieved through post-sulfonation of poly(arylene ether) materials, but this most often results in very high water sorption or even water solubility. Our research has shown that directly polymerized poly(arylene ether) copolymers show important advantages over traditional post-sulfonated systems and also address the concerns with Nafion membranes. These properties were evaluated and correlated with morphology, structure-property relationships, and states of water in the membranes. Further improvements in properties were achieved through incorporation of inorganic

  7. Advanced Imaging and Tissue Engineering of the Human Limbal Epithelial Stem Cell Niche

    PubMed Central

    Massie, Isobel; Dziasko, Marc; Kureshi, Alvena; Levis, Hannah J.; Morgan, Louise; Neale, Michael; Sheth, Radhika; Tovell, Victoria E.; Vernon, Amanda J.; Funderburgh, James L.; Daniels, Julie T.

    2015-01-01

    The limbal epithelial stem cell niche provides a unique, physically protective environment in which limbal epithelial stem cells reside in close proximity with accessory cell types and their secreted factors. The use of advanced imaging techniques is described to visualize the niche in three dimensions in native human corneal tissue. In addition, a protocol is provided for the isolation and culture of three different cell types, including human limbal epithelial stem cells from the limbal niche of human donor tissue. Finally, the process of incorporating these cells within plastic compressed collagen constructs to form a tissue-engineered corneal limbus is described and how immunohistochemical techniques may be applied to characterize cell phenotype therein. PMID:25388395

  8. Advances in mesenchymal stem cell-based strategies for cartilage repair and regeneration.

    PubMed

    Toh, Wei Seong; Foldager, Casper Bindzus; Pei, Ming; Hui, James Hoi Po

    2014-10-01

    Significant research efforts have been undertaken in the last decade in the development of stem cell-based therapies for cartilage repair. Among the various stem cell sources, mesenchymal stem cells (MSCs) demonstrate great promise and clinical efficacy in cartilage regeneration. With a deeper understanding of stem cell biology, new therapeutics and new bioengineering approaches have emerged and showed potential for further developments. Of note, there has been a paradigm shift in applying MSCs for tissue regeneration from the use of stem cells for transplantation to the use of stem cell-derived matrix and secretome components as therapeutic tools and agents for cartilage regeneration. In this review, we will discuss the emerging role of MSCs in cartilage regeneration and the most recent advances in development of stem cell-based therapeutics for cartilage regeneration.

  9. Validation test of advanced technology for IPV nickel-hydrogen flight cells - Update

    NASA Astrophysics Data System (ADS)

    Smithrick, John J.; Hall, Stephen W.

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts with the intention of improving cycle life and performance. One advancement was to use 26 percent potassium hydroxide (KOH) electrolyte to improve cycle life. Another advancement was to modify the state-of-the-art cell design to eliminate identified failure modes. The modified design is referred to as the advanced design. A breakthrough in the LEO cycle life of IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3,500 cycles for cells containing 31 percent KOH. The boiler plate test results are in the process of being validated using flight hardware and real time LEO testing. The primary function of the advanced cell is to store and deliver energy for long-term, LEO spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent KOH electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are: extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion.

  10. Validation test of advanced technology for IPV nickel-hydrogen flight cells - Update

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1992-01-01

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts with the intention of improving cycle life and performance. One advancement was to use 26 percent potassium hydroxide (KOH) electrolyte to improve cycle life. Another advancement was to modify the state-of-the-art cell design to eliminate identified failure modes. The modified design is referred to as the advanced design. A breakthrough in the LEO cycle life of IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3,500 cycles for cells containing 31 percent KOH. The boiler plate test results are in the process of being validated using flight hardware and real time LEO testing. The primary function of the advanced cell is to store and deliver energy for long-term, LEO spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent KOH electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are: extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion.

  11. Hedgehog- and mTOR-targeted therapies for advanced basal cell carcinomas.

    PubMed

    Piérard-Franchimont, Claudine; Hermanns-Lê, Trinh; Paquet, Philippe; Herfs, Michael; Delvenne, Philippe; Piérard, Gérald E

    2015-11-01

    Basal cell carcinomas (BCCs) are the most frequent human cancer. Over 90% of all BCCs have a mutation in PTCH1 or smoothened, two conducting proteins of the Hedgehog pathway. They rarely progress deeply and metastasize; however, if they do, these advanced basal cell carcinoma become amenable to treatment by inhibiting the Hedgehog and the P13K-mTOR pathways. Such innovative drugs include vismodegib, cyclopamine, itraconazole, everolimus and a few other agents that are in early clinical development. PMID:26437034

  12. Steady advance of stem cell therapies: report from the 2011 World Stem Cell Summit, Pasadena, California, October 3-5.

    PubMed

    Swan, Melanie

    2011-12-01

    Stem cell research and related therapies (including regenerative medicine and cellular therapies) could have a significant near-term impact on worldwide public health and aging. One reason is the industry's strong linkage between policy, science, industry, and patient advocacy, as was clear in the attendance and programming at the 7(th) annual World Stem Cell Summit held in Pasadena, California, October 3-5, 2011. A special conference session sponsored by the SENS Foundation discussed how stem cell therapies are being used to extend healthy life span. Stem cells are useful not only in cell-replacement therapies, but also in disease modeling, drug discovery, and drug toxicity screening. Stem cell therapies are currently being applied to over 50 diseases, including heart, lung, neurodegenerative, and eye disease, cancer, and human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Dozens of companies are developing therapeutic solutions that are in different stages of clinical use and clinical trials. Some high-profile therapies include Dendreon's Provenge for prostate cancer, Geron's first-ever embryonic stem cell trials for spinal cord injury, Fibrocell's laViv cellular therapy for wrinkles, and well-established commercial skin substitutes (Organogenesis' Apligraf and Advanced BioHealing's Dermagraft). Stem cell policy issues under consideration include medical tourism, standards for large-scale stem cell manufacturing, and lingering ethical debates over the use of embryonic stem cells. Contemporary stem cell science advances include a focus on techniques for the direct reprogramming of cells from one lineage to another without returning to pluripotency as an intermediary step, improved means of generating and characterizing induced pluripotent cells, and progress in approaches to neurodegenerative disease.

  13. Systems biology of yeast: enabling technology for development of cell factories for production of advanced biofuels.

    PubMed

    de Jong, Bouke; Siewers, Verena; Nielsen, Jens

    2012-08-01

    Transportation fuels will gradually shift from oil based fuels towards alternative fuel resources like biofuels. Current bioethanol and biodiesel can, however, not cover the increasing demand for biofuels and there is therefore a need for advanced biofuels with superior fuel properties. Novel cell factories will provide a production platform for advanced biofuels. However, deep cellular understanding is required for improvement of current biofuel cell factories. Fast screening and analysis (-omics) methods and metabolome-wide mathematical models are promising techniques. An integrated systems approach of these techniques drives diversity and quantity of several new biofuel compounds. This review will cover the recent technological developments that support improvement of the advanced biofuels 1-butanol, biodiesels and jetfuels.

  14. Challenges in optimizing chemoradiation in locally advanced non small-cell lung cancers in India.

    PubMed

    Agrawal, Sushma

    2013-10-01

    Data supporting use of concurrent chemoradiation in locally advanced lung cancers comes from clinical trials from developed countries. Applicability and outcomes of such schedules in developing countries is not widely reported. There are various challenges in delivering chemoradiation in locally advanced non small cell lung cancer in developing countries which is highlighted by an audit of patients treated with chemoradiation in our center. This article deals with the challenges in the context of a developing country. We conclude that sequential chemoradiotherapy is better tolerated than concurrent chemoradiation in Indian patients with locally advanced non-small cell lung cancers. Patients with stage IIIa, normal weight or overweight, and adequate baseline pulmonary function should be offered concurrent chemoradiation.

  15. Hall sensors for extreme temperatures.

    PubMed

    Jankowski, Jakub; El-Ahmar, Semir; Oszwaldowski, Maciej

    2011-01-01

    We report on the preparation of the first complete extreme temperature Hall sensor. This means that the extreme-temperature magnetic sensitive semiconductor structure is built-in an extreme-temperature package especially designed for that purpose. The working temperature range of the sensor extends from -270 °C to +300 °C. The extreme-temperature Hall-sensor active element is a heavily n-doped InSb layer epitaxially grown on GaAs. The magnetic sensitivity of the sensor is ca. 100 mV/T and its temperature coefficient is less than 0.04 %/K. This sensor may find applications in the car, aircraft, spacecraft, military and oil and gas industries.

  16. Electron dynamics in Hall thruster

    NASA Astrophysics Data System (ADS)

    Marini, Samuel; Pakter, Renato

    2015-11-01

    Hall thrusters are plasma engines those use an electromagnetic fields combination to confine electrons, generate and accelerate ions. Widely used by aerospace industries those thrusters stand out for its simple geometry, high specific impulse and low demand for electric power. Propulsion generated by those systems is due to acceleration of ions produced in an acceleration channel. The ions are generated by collision of electrons with propellant gas atoms. In this context, we can realize how important is characterizing the electronic dynamics. Using Hamiltonian formalism, we derive the electron motion equation in a simplified electromagnetic fields configuration observed in hall thrusters. We found conditions those must be satisfied by electromagnetic fields to have electronic confinement in acceleration channel. We present configurations of electromagnetic fields those maximize propellant gas ionization and thus make propulsion more efficient. This work was supported by CNPq.

  17. Factors related to advanced stage oral squamous cell carcinoma in southern Thailand.

    PubMed

    Kerdpon, D; Sriplung, H

    2001-04-01

    A critical factor that indicates a poor prognosis of oral squamous cell carcinoma (OSCC) is advanced stage disease. This study, therefore, aimed to identify the factors related to advanced stage (TNM staging III, IV) OSCC in Thailand. There were 161 patients with squamous cell carcinoma of the oral cavity and lip (ICD-9 140, 141, 143-5), included in the study. Sixty-two per cent of the patients presented with advanced stage disease. Information on demographic characteristics, risk habits, health-seeking behaviour prior to health care professional (HCP) consultation, tumour characteristics and patient and professional delay was obtained by questionnaire-based interview of the patients. These variables were included as initial variables in a logistic regression to calculate the odds ratio (OR) of advanced versus early stage OSCC. Having traditional herbal medication before HCP consultation significantly increased the risk of advanced stage OSCC (OR 5.77; 95% C.I. 1.25-26.62). Floor of mouth location of tumour was associated with a lower risk of advanced stage disease (OR 0.27; 95% C.I. 0.09-0.82) as was having an ulcer (OR 0.43, 95% C.I. 0.02-0.89). The findings indicate that having traditional herbal medication before HCP consultation increased the risk of advanced stage disease. The lower risk of advanced stage OSCC associated with ulcerative tumours and those on the floor of the mouth may be due to their being more readily detected by the patients. PMID:11287274

  18. Advanced Materials and Component Development for Lithium-Ion Cells for NASA Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.

    2012-01-01

    Human missions to Near Earth Objects, such as asteroids, planets, moons, liberation points, and orbiting structures, will require safe, high specific energy, high energy density batteries to provide new or extended capabilities than are possible with today s state-of-the-art aerospace batteries. The Enabling Technology Development and Demonstration Program, High Efficiency Space Power Systems Project battery development effort at the National Aeronautics and Space Administration (NASA) is continuing advanced lithium-ion cell development efforts begun under the Exploration Technology Development Program Energy Storage Project. Advanced, high-performing materials are required to provide improved performance at the component-level that contributes to performance at the integrated cell level in order to meet the performance goals for NASA s High Energy and Ultra High Energy cells. NASA s overall approach to advanced cell development and interim progress on materials performance for the High Energy and Ultra High Energy cells after approximately 1 year of development has been summarized in a previous paper. This paper will provide an update on these materials through the completion of 2 years of development. The progress of materials development, remaining challenges, and an outlook for the future of these materials in near term cell products will be discussed.

  19. Advances in circulating tumor cells (ACTC): from basic research to clinical practice

    PubMed Central

    2013-01-01

    The first 'Advances in Circulating Tumor Cells (ACTC): from Basic Research to Clinical Practice' meeting was held in Athens, Greece, September 26–29, 2012 (abstracts, presentations and a more detailed meeting report are freely available online: http://www.actc2012.org). We summarize in this report most major findings presented and the main conclusions derived during the expert panel sessions. PMID:24314311

  20. Cabozantinib versus everolimus in advanced renal cell carcinoma

    PubMed Central

    Choueiri, Toni K.; Escudier, Bernard; Powles, Thomas; Mainwaring, Paul; Rini, Brian I.; Donskov, Frede; Hammers, Hans; Hutson, Thomas E.; Lee, Jae-Lyun; Peltola, Katriina; Roth, Bruce J.; Bjarnason, Georg A.; Géczi, Lajos; Keam, Bhumsuk; Moroto, Pablo; Heng, Daniel Y. C.; Schmidinger, Manuela; Kantoff, Philip W.; Borgman, Anne; Hessel, Colin; Scheffold, Christian; Schwab, Gisela M.; Tannir, Nizar M.; Motzer, Robert J.

    2016-01-01

    Background Cabozantinib is an oral small molecule tyrosine kinase inhibitor that targets vascular endothelial growth factor receptor (VEGFR) as well as MET and AXL; each has been implicated in metastatic renal cell carcinoma (RCC) pathobiology or development of resistance to antiangiogenic drugs. This randomized open-label phase 3 trial evaluated the efficacy of cabozantinib compared to everolimus in RCC patients who progressed after VEGFR-targeted therapy. Methods The trial randomized 658 patients to receive cabozantinib at a dose of 60 mg daily, or everolimus at a dose of 10 mg daily. The primary endpoint was progression-free survival. Secondary efficacy endpoints were overall survival and objective response rate. Results Median progression-free survival was 7.4 months with cabozantinib and 3.8 months with everolimus. The risk of progression or death was 42% lower with cabozantinib compared to everolimus (hazard ratio, 0.58; 95% confidence interval [CI] 0.45 to 0.75; P < 0.001). Objective response rates were 21% with cabozantinib and 5% with everolimus (P < 0.001). A planned interim analysis showed that overall survival was improved with cabozantinib (hazard ratio, 0.67; 95% CI, 0.51 to 0.89; P = 0.005) but did not cross the significance boundary. Adverse events (grade 3 or 4, regardless of causality) were reported in 74% of cabozantinib patients and 65% of everolimus patients. Discontinuation of study treatment for adverse events occurred in 9.1% of cabozantinib patients and 10% of everolimus patients. Conclusions Cabozantinib improved progression-free survival compared to everolimus in RCC patients who progressed after VEGFR-targeted therapy. PMID:26406150

  1. Is The Intrinsic Spin Hall Effect Measurable?

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoyang

    2005-03-01

    Despite of the large intrinsic spin Hall conductivity in a spin- orbit coupled material predicted theoretically, we show that the intrinsic spin Hall effect in any diffusive sample is not measurable via conventional transport methods, thus the research on the intrinsic spin Hall effect is limited at the pure theoretical content. After generally defining the intrinsic and extrinsic transport coefficients, we show that the intrinsic magnetization Hall current, which is the sum of the intrinsic spin and intrinsic orbit-angular-momentum Hall currents, is identically zero. More importantly, we demonstrate that the equation of motion for the spin density does not depend on the intrinsic spin Hall current, therefore the transverse spin accumulation is solely determined by the extrinsic spin Hall current. The zero intrinsic magnetization Hall current and the independence of the spin accumulation on the intrinsic spin Hall effect lead us to conclude that the intrinsic spin Hall effect can not be assessed by conventional spin transport experiments based on the measurement of the magnetization current and the spin accumulation at the edge of the sample.

  2. Ionization oscillations in Hall accelerators

    NASA Astrophysics Data System (ADS)

    Barral, S.; Peradzyński, Z.

    2010-01-01

    The underlying mechanism of low-frequency oscillations in Hall accelerators is investigated theoretically. It is shown that relaxation oscillations arise from a competition between avalanche ionization and the advective transport of the working gas. The model derived recovers the slow progression and fast recession of the ionization front. Analytical approximations of the shape of current pulses and of the oscillation frequency are provided for the case of large amplitude oscillations.

  3. Hyperbolic supersymmetric quantum Hall effect

    SciTech Connect

    Hasebe, Kazuki

    2008-12-15

    Developing a noncompact version of the supersymmetric Hopf map, we formulate the quantum Hall effect on a superhyperboloid. Based on OSp(1|2) group theoretical methods, we first analyze the one-particle Landau problem, and successively explore the many-body problem where the Laughlin wave function, hard-core pseudopotential Hamiltonian, and topological excitations are derived. It is also shown that the fuzzy superhyperboloid emerges at the lowest Landau level.

  4. Methods for advanced hepatocyte cell culture in microwells utilizing air bubbles.

    PubMed

    Goral, Vasiliy N; Au, Sam H; Faris, Ronald A; Yuen, Po Ki

    2015-02-21

    Flat, two-dimensional (2D) cell culture substrates are simple to use but offer little control over cell morphologies and behavior. In this article, we present a number of novel and unique methods for advanced cell culture in microwells utilizing air bubbles as a way to seed cells in order to provide substantial control over cellular microenvironments and organization to achieve specific cell-based applications. These cell culture methods enable controlled formation of stable air bubbles in the microwells that spontaneously formed when polar solvents such as cell culture media are loaded. The presence of air bubbles (air bubble masking) enables highly controllable cell patterning and organization of seeded cells as well as cell co-culture in microwells. In addition, these cell culture methods are simple to use and implement, yet versatile, and have the potential to provide a wide range of microenvironments to improve in vivo-like behavior for a number of cell types and applications. The air bubble masking technique can also be used to produce a micron thick layer of collagen film suspended on top of the microwells. These collagen film enclosed microwells could provide an easy way for high throughput drug screening and cytotoxicity assays as different drug compounds could be pre-loaded and dried in selected microwells and then released during cell culture.

  5. Some aspects of achieving an ultimate accuracy during insertion device magnetic measurements by a Hall probe

    NASA Astrophysics Data System (ADS)

    Vasserman, I. B.; Strelnikov, N. O.; Xu, J. Z.

    2013-02-01

    An extensive test of a new Senis 2-axis Hall probe was done at the Advanced Photon Source using the Undulator A device and calibration system. This new probe has clear advantages compared with previously used Bell and Sentron Hall probes: very stable zero offset (less than the noise of 0.026 G) and compensated planar Hall effect. It can be used with proper calibration even for first and second field integral measurements. A comparison with reference measurements by long stretched coil shows that the difference in the first field integral measurement results for a 2.4-m-long Undulator A device is between 17 G cm for the best of four Hall probes used for the test and 51 G cm for the worst of them for all gap ranges from 10.5 mm to 150 mm.

  6. Some aspects of achieving an ultimate accuracy during insertion device magnetic measurements by a Hall probe.

    PubMed

    Vasserman, I B; Strelnikov, N O; Xu, J Z

    2013-02-01

    An extensive test of a new Senis 2-axis Hall probe was done at the Advanced Photon Source using the Undulator A device and calibration system. This new probe has clear advantages compared with previously used Bell and Sentron Hall probes: very stable zero offset (less than the noise of 0.026 G) and compensated planar Hall effect. It can be used with proper calibration even for first and second field integral measurements. A comparison with reference measurements by long stretched coil shows that the difference in the first field integral measurement results for a 2.4-m-long Undulator A device is between 17 G cm for the best of four Hall probes used for the test and 51 G cm for the worst of them for all gap ranges from 10.5 mm to 150 mm.

  7. Some aspects of achieving an ultimate accuracy during insertion device magnetic measurements by a Hall probe

    SciTech Connect

    Vasserman, I. B.; Xu, J. Z.; Strelnikov, N. O.

    2013-02-15

    An extensive test of a new Senis 2-axis Hall probe was done at the Advanced Photon Source using the Undulator A device and calibration system. This new probe has clear advantages compared with previously used Bell and Sentron Hall probes: very stable zero offset (less than the noise of 0.026 G) and compensated planar Hall effect. It can be used with proper calibration even for first and second field integral measurements. A comparison with reference measurements by long stretched coil shows that the difference in the first field integral measurement results for a 2.4-m-long Undulator A device is between 17 G cm for the best of four Hall probes used for the test and 51 G cm for the worst of them for all gap ranges from 10.5 mm to 150 mm.

  8. Advances in Mammalian Cell Line Development Technologies for Recombinant Protein Production

    PubMed Central

    Lai, Tingfeng; Yang, Yuansheng; Ng, Say Kong

    2013-01-01

    From 2006 to 2011, an average of 15 novel recombinant protein therapeutics have been approved by US Food and Drug Administration (FDA) annually. In addition, the expiration of blockbuster biologics has also spurred the emergence of biosimilars. The increasing numbers of innovator biologic products and biosimilars have thus fuelled the demand of production cell lines with high productivity. Currently, mammalian cell line development technologies used by most biopharmaceutical companies are based on either the methotrexate (MTX) amplification technology or the glutamine synthetase (GS) system. With both systems, the cell clones obtained are highly heterogeneous, as a result of random genome integration by the gene of interest and the gene amplification process. Consequently, large numbers of cell clones have to be screened to identify rare stable high producer cell clones. As such, the cell line development process typically requires 6 to 12 months and is a time, capital and labour intensive process. This article reviews established advances in protein expression and clone screening which are the core technologies in mammalian cell line development. Advancements in these component technologies are vital to improve the speed and efficiency of generating robust and highly productive cell line for large scale production of protein therapeutics. PMID:24276168

  9. DESIGN, PROTOTYPE AND MEASUREMENT OF A SINGLE-CELL DEFLECTING CAVITY FOR THE ADVANCED PHOTON SOURCE

    SciTech Connect

    Haipeng Wang, Guangfeng Cheng, Gianluigi Ciovati, Peter Kneisel, Robert Rimmer, Kai Tian, Larry Turlington, Alireza Nassiri, Geoff Waldschmidt

    2009-05-01

    After the design optimization of a squashed elliptical shape, single-cell, superconducting (SC) deflecting cavity at 2.815 GHz, a copper prototype has been bench measured to determine its rf properties and the effectiveness of waveguide damping of parasitic modes [1]. RF cold tests were also performed at 2K on niobium single-cell and two-cell prototype cavities. Details of impedance calculation using wakefiled analysis of the single-cell cavity are shown to meet the strict 200 mA beam stability requirement of the Advanced Photon Source (APS) at Argonne National Lab where a total of 16 single-cell cavities will be divided into two cryomodule. The design of higher-order mode (HOM) waveguide damping, the simulations of the Lorenz force detuning, and the prototype of on-cell damping are presented.

  10. Alginate cell encapsulation: new advances in reproduction and cartilage regenerative medicine

    PubMed Central

    Ghidoni, Ilaria; Chlapanidas, Theodora; Bucco, Massimo; Crovato, Francesca; Marazzi, Mario; Vigo, Daniele; Torre, Maria Luisa

    2008-01-01

    Cell encapsulation, a strategy whereby a pool of live cells is entrapped within a semipermeable membrane, represents an evolving branch of biotechnology and regenerative medicine. For example, over the last 20 years, male and female gametes and embryos have been encapsulated with or without somatic cells for different purposes, such as in vitro gametogenesis, embryo culture, cell preservation and semen controlled release. Beside that, cell encapsulation technology in alginate, which is a natural biodegradable polymer that mimics the extracellular matrix and supports both cell functions and metabolism, has been developed with the aim of obtaining three-dimensional (3D) cultures. In this context, adipose-derived stromal vascular fraction (SVF) has attracted more and more attention because of its enormous potential in tissue regeneration. In fact, the SVF represents a rich source of mesenchymal cells (ADSCs), potentially able to differentiate into adipocytes, chondrocytes, osteoblasts, myocytes, cardiomyocytes, hepatocytes, and neuronal, epithelial and endothelial cells. These cells are ideal candidates for use in regenerative medicine, tissue engineering, including gene therapy and cell replacement cancer therapies. As long as technological resources are available for large-scale cell encapsulation intended for advanced therapies (gene therapy, somatic cell therapy and tissue engineering), the state-of-the-art in this field is reviewed in terms of scientific literature. PMID:19002776

  11. Comparative study on the performance of five different Hall effect devices.

    PubMed

    Paun, Maria-Alexandra; Sallese, Jean-Michel; Kayal, Maher

    2013-02-05

    Five different Hall Effect sensors were modeled and their performance evaluated using a three dimensional simulator. The physical structure of the implemented sensors reproduces a certain technological fabrication process. Hall voltage, absolute, current-related, voltage-related and power-related sensitivities were obtained for each sensor. The effect of artificial offset was also investigated for cross-like structures. The simulation procedure guides the designer in choosing the Hall cell optimum shape, dimensions and device polarization conditions that would allow the highest performance.

  12. Comparative Study on the Performance of Five Different Hall Effect Devices

    PubMed Central

    Paun, Maria-Alexandra; Sallese, Jean-Michel; Kayal, Maher

    2013-01-01

    Five different Hall Effect sensors were modeled and their performance evaluated using a three dimensional simulator. The physical structure of the implemented sensors reproduces a certain technological fabrication process. Hall voltage, absolute, current-related, voltage-related and power-related sensitivities were obtained for each sensor. The effect of artificial offset was also investigated for cross-like structures. The simulation procedure guides the designer in choosing the Hall cell optimum shape, dimensions and device polarization conditions that would allow the highest performance. PMID:23385419

  13. Dental Stem Cell in Tooth Development and Advances of Adult Dental Stem Cell in Regenerative Therapies.

    PubMed

    Tan, Jiali; Xu, Xin; Lin, Jiong; Fan, Li; Zheng, Yuting; Kuang, Wei

    2015-01-01

    Stem cell-based therapies are considered as a promising treatment for many clinical usage such as tooth regeneration, bone repairation, spinal cord injury, and so on. However, the ideal stem cell for stem cell-based therapy still remains to be elucidated. In the past decades, several types of stem cells have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs) and stem cells from apical papilla (SCAP), which may be a good source for stem cell-based therapy in certain disease, especially when they origin from neural crest is considered. In this review, the specific characteristics and advantages of the adult dental stem cell population will be summarized and the molecular mechanisms of the differentiation of dental stem cell during tooth development will be also discussed.

  14. Fort Hall air emissions study, Fort Hall Indian Reservation, Fort Hall, Idaho

    SciTech Connect

    Metcalf, S.W.; Sonnenfeld, N.L.; Rolka, D.L.; Kaye, W.E.

    1995-11-01

    The Agency for Toxic Substances and Disease Registry (ATSDR) conducted a cross-sectional health study at the Fort Hall Indian Reservation in Idaho to investigate concerns about the health effects on reservation residents that might be attributed to two phosphate-processing plants located near the reservation`s southern border. In addition to increased particulates, air emissions from these plants included phosphorus pentoxide, cadmium, chromium, fluoride, uranium, and its daughter radionuclides. A total of 515 participants -- 229 from Fort Hall and 286 from a comparison group at the Duck Valley Indian Reservation -- were interviewed in person by trained American Indian interviewers. Approximately 100 residents of each reservation performed pulmonary function tests and provided urine specimens that were analyzed for cadmium, chromium, fluoride, and several renal biomarkers.

  15. Advanced Materials and Component Development for Lithium-ion Cells for NASA Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.

    2012-01-01

    Human missions to Near Earth Objects, such as asteroids, planets, moons, libration points, and orbiting structures, will require safe, high specific energy, high energy density batteries to provide new or extended capabilities than are possible with today s state-of-the-art aerospace batteries. The National Aeronautics and Space Administration is developing advanced High Energy and Ultra High Energy lithium-ion cells to address these needs. In order to meet the performance goals, advanced, high-performing materials are required to provide improved performance at the component-level that contributes to performance at the integrated cell level. This paper will provide an update on the performance of experimental materials through the completion of two years of development. The progress of materials development, remaining challenges, and an outlook for the future of these materials in near term cell products will be discussed.

  16. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: First Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-03-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This report provides the early data results and implementation experience of the AT fuel cell bus since it was placed in service.

  17. Advances in osteosarcoma stem cell research and opportunities for novel therapeutic targets.

    PubMed

    Yan, Guang-Ning; Lv, Yang-Fan; Guo, Qiao-Nan

    2016-01-28

    Osteosarcoma is the most common type of bone cancer, especially in children and young adults. The primary treatment for osteosarcoma is a combination of surgery and chemotherapy, however prognoses remain poor due to chemoresistance and early metastases. Osteosarcoma stem cells appear to play central roles in tumor recurrence, metastases and chemoresistance via self-renewal and differentiation. Targeting these cells may provide a novel strategy in the treatment of osteosarcoma. This review summarizes current knowledge of this rare phenotype and recent advances in understanding the functions OSCs (osteosarcoma stem cells) in osteosarcoma, with the aim of improving therapies in the future.

  18. Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator.

    PubMed

    Feng, Yang; Feng, Xiao; Ou, Yunbo; Wang, Jing; Liu, Chang; Zhang, Liguo; Zhao, Dongyang; Jiang, Gaoyuan; Zhang, Shou-Cheng; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Yayu

    2015-09-18

    We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau. PMID:26431002

  19. NASA - 77M prototype hall thruster built under the High Voltage Hall accelerator development project

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA - 77M prototype hall thruster built under the High Voltage Hall accelerator development project funded by the Science Mission Directorate ; potential use is propulsion for deep space science missions

  20. Rapid Response of Advanced Squamous Non-Small Cell Lung Cancer with Thrombocytopenia after First-Line Treatment with Pembrolizumab Plus Autologous Cytokine-Induced Killer Cells.

    PubMed

    Hui, Zhenzhen; Zhang, Xinwei; Ren, Baozhu; Li, Runmei; Ren, Xiubao

    2015-01-01

    We present the first clinical evidence of advanced squamous non-small cell lung cancer with severe thrombocytopenia showing dramatic improvement after first-line treatment with pembrolizumab plus autologous cytokine-induced killer cells.

  1. Sonidegib, a novel smoothened inhibitor for the treatment of advanced basal cell carcinoma

    PubMed Central

    Doan, Hung Q; Silapunt, Sirunya; Migden, Michael R

    2016-01-01

    Basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer. If left untreated, BCCs can become locally aggressive or even metastasize. Currently available treatments include local destruction, surgery, and radiation. Systemic options for advanced disease are limited. The Hedgehog (Hh) pathway is aberrantly activated in a majority of BCCs and in other cancers. Hh pathway inhibitors are targeted agents that inhibit the aberrant activation of the Hh pathway, with smoothened being a targeted component. Sonidegib is a novel smoothened inhibitor that was recently approved by the US Food and Drug Administration. This review focuses on BCC pathogenesis and the clinical efficacy of sonidegib for the treatment of advanced BCC. PMID:27695345

  2. Sonidegib, a novel smoothened inhibitor for the treatment of advanced basal cell carcinoma

    PubMed Central

    Doan, Hung Q; Silapunt, Sirunya; Migden, Michael R

    2016-01-01

    Basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer. If left untreated, BCCs can become locally aggressive or even metastasize. Currently available treatments include local destruction, surgery, and radiation. Systemic options for advanced disease are limited. The Hedgehog (Hh) pathway is aberrantly activated in a majority of BCCs and in other cancers. Hh pathway inhibitors are targeted agents that inhibit the aberrant activation of the Hh pathway, with smoothened being a targeted component. Sonidegib is a novel smoothened inhibitor that was recently approved by the US Food and Drug Administration. This review focuses on BCC pathogenesis and the clinical efficacy of sonidegib for the treatment of advanced BCC.

  3. Advances in Cell and Gene-based Therapies for Cystic Fibrosis Lung Disease

    PubMed Central

    Oakland, Mayumi; Sinn, Patrick L; McCray Jr, Paul B

    2012-01-01

    Cystic fibrosis (CF) is a disease characterized by airway infection, inflammation, remodeling, and obstruction that gradually destroy the lungs. Direct delivery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene to airway epithelia may offer advantages, as the tissue is accessible for topical delivery of vectors. Yet, physical and host immune barriers in the lung present challenges for successful gene transfer to the respiratory tract. Advances in gene transfer approaches, tissue engineering, and novel animal models are generating excitement within the CF research field. This review discusses current challenges and advancements in viral and nonviral vectors, cell-based therapies, and CF animal models. PMID:22371844

  4. Biopsy Needle Advancement during Bone Marrow Aspiration Increases Mesenchymal Stem Cell Concentration

    PubMed Central

    Peters, Anne E.; Watts, Ashlee E.

    2016-01-01

    Point-of-care kits to concentrate bone marrow (BM)-derived mesenchymal stem cells (MSCs) are used clinically in horses. A maximal number of MSCs per milliliter of marrow aspirated might be desired prior to use of a point-of-care system to concentrate MSCs. Our objective was to test a method to increase the number of MSCs per milliliter of marrow collected. We collected two BM aspirates using two different collection techniques from 12 horses. The first collection technique was to aspirate BM from a single site without advancement of the biopsy needle. The second collection technique was to aspirate marrow from multiple sites within the same sternal puncture by advancing the needle 5 mm three times for BM aspiration from four sites. Numbers of MSCs in collected BM were assessed by total nucleated cell count of BM after aspiration, total colony-forming unit-fibroblast (CFU-F) assay, and total MSC number at each culture passage. The BM aspiration technique of four needle advancements during BM aspiration resulted in higher initial nucleated cell counts, more CFU-Fs, and more MSCs at the first passage. There were no differences in the number of MSCs at later passages. Multiple advancements of the BM needle during BM aspiration resulted in increased MSC concentration at the time of BM collection. If a point-of-care kit is used to concentrate MSCs, multiple advancements may result in higher MSC numbers in the BM concentrate after preparation by the point-of-care kit. For culture expanded MSCs beyond the first cell passage, the difference is of questionable clinical relevance. PMID:27014705

  5. Advances of mesenchymal stem cells derived from bone marrow and dental tissue in craniofacial tissue engineering.

    PubMed

    Yang, Maobin; Zhang, Hongming; Gangolli, Riddhi

    2014-05-01

    Bone and dental tissues in craniofacial region work as an important aesthetic and functional unit. Reconstruction of craniofacial tissue defects is highly expected to ensure patients to maintain good quality of life. Tissue engineering and regenerative medicine have been developed in the last two decades, and been advanced with the stem cell technology. Bone marrow derived mesenchymal stem cells are one of the most extensively studied post-natal stem cell population, and are widely utilized in cell-based therapy. Dental tissue derived mesenchymal stem cells are a relatively new stem cell population that isolated from various dental tissues. These cells can undergo multilineage differentiation including osteogenic and odontogenic differentiation, thus provide an alternative source of mesenchymal stem cells for tissue engineering. In this review, we discuss the important issues in mesenchymal stem cell biology including the origin and functions of mesenchymal stem cells, compare the properties of these two types of mesenchymal cells, update recent basic research and clinic applications in this field, and address important future challenges.

  6. Disruption of CCL20-CCR6 interaction inhibits metastasis of advanced cutaneous T-cell lymphoma

    PubMed Central

    Ito, Mitsugu; Abe, Fumito; Nara, Miho; Watanabe, Atsushi; Takahashi, Naoto; Miyagaki, Tomomitsu; Sugaya, Makoto; Tagawa, Hiroyuki

    2016-01-01

    We recently demonstrated that upregulation of a chemokine receptor CCR6 and its ligand CCL20 led to metastasis of advanced cutaneous T-cell lymphoma (CTCL) cells, suggesting the involvement of CCL20-CCR6 interaction in initiating CTCL cell metastasis. In this study, we determined whether this interaction is functional in metastatic CTCL cells. We first demonstrated increased STAT3 expression during the progression of primary CTCL. STAT3 was spontaneously activated and mediated the transcription of CCL20 in CTCL cell lines. Next, to determine whether the transient knockdown of STAT3, CCL20, or CCR6 or treatment with neutralizing antibody against CCL20 (neutralizing CCL20 antibody) could reduce the migration ability of CTCL cells, we conducted an in vitro migration assay. All treatments reduced the nutrition-dependent migration activity of CTCL cells. Notably, treatment with neutralizing CCL20 antibody reduced the migration ability of the cells without decreasing the expression of CCL20 and CCR6. This demonstrated that the CCL20-CCR6 interaction is actually functional in metastatic CTCL cells. Finally, to examine the in vivo effect of neutralizing CCL20 antibody, we used NOD/Shi-scid IL-2γnul mice inoculated with CTCL cells. These mice were expected to die due to metastasis of CTCL cells into multiple organs. However, administration of neutralizing CCL20 antibody significantly prolonged the survival of the xenografted mice. These findings suggested that automatic activation of the STAT3/CCL20/CCR6 cascade was involved in CTCL lymphomagenesis and that disruption of CCL20-CCR6 interaction could be a key therapeutic strategy against advanced CTCL. PMID:26789110

  7. Listening to the acoustics in concert halls

    NASA Astrophysics Data System (ADS)

    Beranek, Leo L.; Griesinger, David

    2001-05-01

    How does acoustics affect the symphonic music performed in a concert hall? The lecture begins with an illustrated discussion of the architectural features that influence the acoustics. Boston Symphony Hall, which was built in 1900 when only one facet of architectural design was known, now rates as one of the world's great halls. How this occurred will be presented. Music is composed with some acoustical environment in mind and this varies with time from the Baroque to the Romantic to the Modern musical period. Conductors vary their interpretation according to the hall they are in. Well-traveled listeners and music critics have favorite halls. The lecture then presents a list of 58 halls rank ordered according to their acoustical quality based on interviews of music critics and conductors. Modern acoustical measurements made in these halls are compared with their rankings. Music recordings will be presented that demonstrate how halls sound that have different measured acoustical parameters. Photographs of a number of recently built halls are shown as examples of how these known acoustical factors have been incorporated into architectural design.

  8. Anomalous Hall effect in localization regime

    NASA Astrophysics Data System (ADS)

    Wu, Lin; Zhu, Kai; Yue, Di; Tian, Yuan; Jin, Xiaofeng

    2016-06-01

    The anomalous Hall effect in the ultrathin film regime is investigated in Fe(001)(1-3 nm) films epitaxial on MgO(001). The logarithmic localization correction to longitudinal resistivity and anomalous Hall resistivity are observed at low temperature. We identify that the coefficient of skew scattering has a reduction from metallic to localized regime, while the contribution of side jump has inconspicuous change except for a small drop below 10 K. Furthermore, we discover that the intrinsic anomalous Hall conductivity decreases with the reduction of thickness below 2 nm. Our results provide unambiguous experimental evidence to clarify the problem of localization correction to the anomalous Hall effect.

  9. Hall Thruster Technology for NASA Science Missions

    NASA Technical Reports Server (NTRS)

    Manzella, David; Oh, David; Aadland, Randall

    2005-01-01

    The performance of a prototype Hall thruster designed for Discovery-class NASA science mission applications was evaluated at input powers ranging from 0.2 to 2.9 kilowatts. These data were used to construct a throttle profile for a projected Hall thruster system based on this prototype thruster. The suitability of such a Hall thruster system to perform robotic exploration missions was evaluated through the analysis of a near Earth asteroid sample return mission. This analysis demonstrated that a propulsion system based on the prototype Hall thruster offers mission benefits compared to a propulsion system based on an existing ion thruster.

  10. Anomalous Hall effect in ferromagnetic semiconductors.

    PubMed

    Jungwirth, T; Niu, Qian; MacDonald, A H

    2002-05-20

    We present a theory of the anomalous Hall effect in ferromagnetic (III, Mn)V semiconductors. Our theory relates the anomalous Hall conductance of a homogeneous ferromagnet to the Berry phase acquired by a quasiparticle wave function upon traversing closed paths on the spin-split Fermi surface. The quantitative agreement between our theory and experimental data in both (In, Mn)As and (Ga, Mn)As systems suggests that this disorder independent contribution to the anomalous Hall conductivity dominates in diluted magnetic semiconductors. The success of this model for (III, Mn)V materials is unprecedented in the longstanding effort to understand origins of the anomalous Hall effect in itinerant ferromagnets.

  11. Mesoscopic spin Hall effect in semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Zarbo, Liviu

    , appeared in 1970s, it is only in the past few years that advances in optical detection of nonequilibrium magnetization in semiconductors have made possible the detection of such extrinsic SHE in groundbreaking experiments. The experimental pursuits of SHE have, in fact, been largely motivated by very recent theoretical speculations for several order of magnitude greater spin Hall currents driven by intrinsic SO mechanisms due to SO couplings existing not only around the impurity but also throughout the sample. The homogeneous intrinsic SO couplings are capable of spin-splitting the band structure and appear as momentum-dependent magnetic field within the sample which causes spin non-conservation due to precession of injected spins which are not in the eigenstates of the corresponding Zeeman term. Besides deepening our understanding of subtle relativistic effects in solids, SHE has attracted a lot of attention since it offers an all-electrical way of generating pure spin currents in semiconductors. (Abstract shortened by UMI.)

  12. An advanced space photovoltaic concentrator array using Fresnel lenses, gallium arsenide cells, and prismatic cell covers

    NASA Technical Reports Server (NTRS)

    O'Neill, Mark J.; Piszczor, Michael F.

    1988-01-01

    The current status of a space concentrator array which uses refractive optics, gallium arsenide cells, and prismatic cell covers to achieve excellent performance at a very low array mass is documented. The prismatically covered cells have established records for space cell performance (24.2 percent efficient at 100 AM0 suns and 25 C) and terrestrial single-junction cell performance (29.3 percent efficient at 200 AM1.5 suns and 25 C).

  13. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Fourth Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2013-01-01

    SunLine Transit Agency, which provides public transit services to the Coachella Valley area of California, has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technology (AT) fuel cell bus with a hybrid electric propulsion system, fuel cell power system, and lithium-based hybrid batteries. This report describes operations at SunLine for the AT fuel cell bus and five compressed natural gas buses. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working with SunLine to evaluate the bus in real-world service to document the results and help determine the progress toward technology readiness. NREL has previously published three reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from February 2012 through November 2012.

  14. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques

    PubMed Central

    Dirk, Brennan S.; Van Nynatten, Logan R.; Dikeakos, Jimmy D.

    2016-01-01

    Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell–cell transmission and cell–free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle. PMID:27775563

  15. Recent advances in haploidentical hematopoietic stem cell transplantation using ex vivo T cell-depleted graft in children and adolescents

    PubMed Central

    Koh, Kyung-Nam; Seo, Jong Jin

    2016-01-01

    Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for children and adolescents with various malignant and non-malignant diseases. While human leukocyte antigen (HLA)-identical sibling donor is the preferred choice, matched unrelated volunteer donor is another realistic option for successful HSCT. Unfortunately, it is not always possible to find a HLA-matched donor for patients requiring HSCT, leading to a considerable number of deaths of patients without undergoing transplantation. Alternatively, allogeneic HSCT from haploidentical family members could provide donors for virtually all patients who need HSCT. Although the early attempts at allogeneic HSCT from haploidentical family donor (HFD) were disappointing, recent advances in the effective ex vivo depletion of T cells or unmanipulated in vivo regulation of T cells, better supportive care, and optimal conditioning regimens have significantly improved the outcomes of haploidentical HSCT. The ex vivo techniques used to remove T cells have evolved from the selection of CD34+ hematopoietic stem cell progenitors to the depletion of CD3+ cells, and more recently to the depletion of αβ+ T cells. The recent emerging evidence for ex vivo T cell-depleted haploidentical HSCT has provided additional therapeutic options for pediatric patients with diseases curable by HSCT but has not found a suitable related or unrelated donor. This review discusses recent advances in haploidentical HSCT, focusing on transplant using ex vivo T cell-depleted grafts. In addition, our experiences with this novel approach for the treatment of pediatric patients with malignant and non-malignant diseases are described. PMID:27104186

  16. Recent advances in haploidentical hematopoietic stem cell transplantation using ex vivo T cell-depleted graft in children and adolescents.

    PubMed

    Im, Ho Joon; Koh, Kyung-Nam; Seo, Jong Jin

    2016-03-01

    Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for children and adolescents with various malignant and non-malignant diseases. While human leukocyte antigen (HLA)-identical sibling donor is the preferred choice, matched unrelated volunteer donor is another realistic option for successful HSCT. Unfortunately, it is not always possible to find a HLA-matched donor for patients requiring HSCT, leading to a considerable number of deaths of patients without undergoing transplantation. Alternatively, allogeneic HSCT from haploidentical family members could provide donors for virtually all patients who need HSCT. Although the early attempts at allogeneic HSCT from haploidentical family donor (HFD) were disappointing, recent advances in the effective ex vivo depletion of T cells or unmanipulated in vivo regulation of T cells, better supportive care, and optimal conditioning regimens have significantly improved the outcomes of haploidentical HSCT. The ex vivo techniques used to remove T cells have evolved from the selection of CD34(+) hematopoietic stem cell progenitors to the depletion of CD3(+) cells, and more recently to the depletion of αβ(+) T cells. The recent emerging evidence for ex vivo T cell-depleted haploidentical HSCT has provided additional therapeutic options for pediatric patients with diseases curable by HSCT but has not found a suitable related or unrelated donor. This review discusses recent advances in haploidentical HSCT, focusing on transplant using ex vivo T cell-depleted grafts. In addition, our experiences with this novel approach for the treatment of pediatric patients with malignant and non-malignant diseases are described.

  17. Town Hall with Secretary Moniz

    ScienceCinema

    Energy Secretary Ernest Moniz; Deputy Secretary of Energy Daniel Poneman

    2016-07-12

    In a town hall meeting with Department staff, Energy Secretary Ernest Moniz spoke about his plans for a reorganization of the Energy Department’s management structure. The plans will help better achieve the Department’s key priorities and those of the President, including implementing the President’s Climate Action Plan, “all of the above” energy strategy and nuclear security agenda. After his remarks, Moniz, joined by Deputy Secretary Dan Poneman, took questions from the audience in the Forrestal Auditorium as well as email questions from other Department locations.

  18. Hall-effect arc protector

    DOEpatents

    Rankin, R.A.; Kotter, D.K.

    1997-05-13

    The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored. 2 figs.

  19. Hall-effect arc protector

    DOEpatents

    Rankin, Richard A.; Kotter, Dale K.

    1997-01-01

    The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored.

  20. Temperature Gradient in Hall Thrusters

    SciTech Connect

    D. Staack; Y. Raitses; N.J. Fisch

    2003-11-24

    Plasma potentials and electron temperatures were deduced from emissive and cold floating probe measurements in a 2 kW Hall thruster, operated in the discharge voltage range of 200-400 V. An almost linear dependence of the electron temperature on the plasma potential was observed in the acceleration region of the thruster both inside and outside the thruster. This result calls into question whether secondary electron emission from the ceramic channel walls plays a significant role in electron energy balance. The proportionality factor between the axial electron temperature gradient and the electric field is significantly smaller than might be expected by models employing Ohmic heating of electrons.

  1. Theory of Quantum Hall Nematics

    NASA Astrophysics Data System (ADS)

    Radzihovsky, Leo; Dorsey, Alan T.

    2002-05-01

    Transport measurements on two-dimensional electron systems in moderate magnetic fields suggest the existence of a spontaneously orientationally ordered, compressible liquid state. We develop and analyze a microscopic theory of such a ``quantum Hall nematic'' (QHN) phase, predict the existence of a novel, highly anisotropic q3 density-director mode, find that the T = 0 long-range orientational order is unstable to weak disorder, and compute the tunneling into such a strongly correlated state. This microscopic approach is supported and complemented by a hydrodynamic model of the QHN, which, in the dissipationless limit, reproduces the modes of the microscopic model.

  2. Theory of quantum Hall nematics.

    PubMed

    Radzihovsky, Leo; Dorsey, Alan T

    2002-05-27

    Transport measurements on two-dimensional electron systems in moderate magnetic fields suggest the existence of a spontaneously orientationally ordered, compressible liquid state. We develop and analyze a microscopic theory of such a "quantum Hall nematic" (QHN) phase, predict the existence of a novel, highly anisotropic q(3) density-director mode, find that the T = 0 long-range orientational order is unstable to weak disorder, and compute the tunneling into such a strongly correlated state. This microscopic approach is supported and complemented by a hydrodynamic model of the QHN, which, in the dissipationless limit, reproduces the modes of the microscopic model. PMID:12059490

  3. Town Hall with Secretary Moniz

    SciTech Connect

    Energy Secretary Ernest Moniz; Deputy Secretary of Energy Daniel Poneman

    2013-07-18

    In a town hall meeting with Department staff, Energy Secretary Ernest Moniz spoke about his plans for a reorganization of the Energy Department’s management structure. The plans will help better achieve the Department’s key priorities and those of the President, including implementing the President’s Climate Action Plan, “all of the above” energy strategy and nuclear security agenda. After his remarks, Moniz, joined by Deputy Secretary Dan Poneman, took questions from the audience in the Forrestal Auditorium as well as email questions from other Department locations.

  4. Electron Transport in Hall Thrusters

    NASA Astrophysics Data System (ADS)

    McDonald, Michael Sean

    Despite high technological maturity and a long flight heritage, computer models of Hall thrusters remain dependent on empirical inputs and a large part of thruster development to date has been heavily experimental in nature. This empirical approach will become increasingly unsustainable as new high-power thrusters tax existing ground test facilities and more exotic thruster designs stretch and strain the boundaries of existing design experience. The fundamental obstacle preventing predictive modeling of Hall thruster plasma properties and channel erosion is the lack of a first-principles description of electron transport across the strong magnetic fields between the cathode and anode. In spite of an abundance of proposed transport mechanisms, accurate assessments of the magnitude of electron current due to any one mechanism are scarce, and comparative studies of their relative influence on a single thruster platform simply do not exist. Lacking a clear idea of what mechanism(s) are primarily responsible for transport, it is understandably difficult for the electric propulsion scientist to focus his or her theoretical and computational tools on the right targets. This work presents a primarily experimental investigation of collisional and turbulent Hall thruster electron transport mechanisms. High-speed imaging of the thruster discharge channel at tens of thousands of frames per second reveals omnipresent rotating regions of elevated light emission, identified with a rotating spoke instability. This turbulent instability has been shown through construction of an azimuthally segmented anode to drive significant cross-field electron current in the discharge channel, and suggestive evidence points to its spatial extent into the thruster near-field plume as well. Electron trajectory simulations in experimentally measured thruster electromagnetic fields indicate that binary collisional transport mechanisms are not significant in the thruster plume, and experiments

  5. Advanced Research Deposition System (ARDS) for processing CdTe solar cells

    NASA Astrophysics Data System (ADS)

    Barricklow, Keegan Corey

    CdTe solar cells have been commercialized at the Gigawatt/year level. The development of volume manufacturing processes for next generation CdTe photovoltaics (PV) with higher efficiencies requires research systems with flexibility, scalability, repeatability and automation. The Advanced Research Deposition Systems (ARDS) developed by the Materials Engineering Laboratory (MEL) provides such a platform for the investigation of materials and manufacturing processes necessary to produce the next generation of CdTe PV. Limited by previous research systems, the ARDS was developed to provide process and hardware flexibility, accommodating advanced processing techniques, and capable of producing device quality films. The ARDS is a unique, in-line process tool with nine processing stations. The system was designed, built and assembled at the Materials Engineering Laboratory. Final assembly, startup, characterization and process development are the focus of this research. Many technical challenges encountered during the startup of the ARDS were addressed in this research. In this study, several hardware modifications needed for the reliable operation of the ARDS were designed, constructed and successfully incorporated into the ARDS. The effect of process condition on film properties for each process step was quantified. Process development to achieve 12% efficient baseline solar cell required investigation of discrete processing steps, troubleshooting process variation, and developing performance correlations. Subsequent to this research, many advances have been demonstrated with the ARDS. The ARDS consistently produces devices of 12% +/-.5% by the process of record (POR). The champion cell produced to date utilizing the ARDS has an efficiency of 16.2% on low cost commercial sodalime glass and utilizes advanced films. The ARDS has enabled investigation of advanced concepts for processing CdTe devices including, Plasma Cleaning, Plasma Enhanced Closed Space Sublimation

  6. Advances in the theory and application of BSF cells. [including electrical resistivity and photovoltaic cells

    NASA Technical Reports Server (NTRS)

    Mandelkorn, J.; Lamneck, J. H.

    1975-01-01

    The characteristics and behavior of p(+), p solar cells were investigated. The p(+), p cells were made by the removal of the n(+) surface layers from n(+), p p(+), BSF cells followed by application of a suitable contact to the resultant p(+), p structures. The open circuit voltage of p(+), p cells was found to increase with increasing 'p' bulk resistivity. The measured open circuit velocity-temperature coefficients were positive and increased with increasing resistivity. An outline of prior limitations in solar cell design is presented, and the removal of these limitations through use of BSF effects is pointed out. The study of BSF effects made feasible production of very thin high efficiency silicon cells as well as high resistivity-high efficiency cells, two desirable types of silicon cells which were previously impossible to make.

  7. Robotics, Stem Cells and Brain Computer Interfaces in Rehabilitation and Recovery from Stroke; Updates and Advances

    PubMed Central

    Boninger, Michael L; Wechsler, Lawrence R.; Stein, Joel

    2014-01-01

    Objective To describe the current state and latest advances in robotics, stem cells, and brain computer interfaces in rehabilitation and recovery for stroke. Design The authors of this summary recently reviewed this work as part of a national presentation. The paper represents the information included in each area. Results Each area has seen great advances and challenges as products move to market and experiments are ongoing. Conclusion Robotics, stem cells, and brain computer interfaces all have tremendous potential to reduce disability and lead to better outcomes for patients with stroke. Continued research and investment will be needed as the field moves forward. With this investment, the potential for recovery of function is likely substantial PMID:25313662

  8. New molecular targeted therapies for advanced non-small-cell lung cancer

    PubMed Central

    Méndez, Míriam; Custodio, Ana; Provencio, Mariano

    2011-01-01

    Non-small-cell lung cancer (NSCLC) is a uniformly fatal disease and most patients will present with advanced stage. Treatment outcomes remain unsatisfactory, with low long-term survival rates. Standard treatment, such as palliative chemotherapy and radiotherapy, offers a median survival not exceeding 1 year. Hence, considerable efforts have started to be made in order to identify new biological agents which may safely and effectively be administered to advanced NSCLC patients. Two cancer cell pathways in particular have been exploited, the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor receptor (VEGFR) pathways. However, novel targeted therapies that interfere with other dysregulated pathways in lung cancer are already in the clinic. This review outlines the most promising research approaches to the treatment of NSCLC, discussed according to the specific molecular pathway targeted. PMID:22263060

  9. The fluctuation Hall conductivity and the Hall angle in type-II superconductor under magnetic field

    NASA Astrophysics Data System (ADS)

    Tinh, Bui Duc; Hoc, Nguyen Quang; Thu, Le Minh

    2016-02-01

    The fluctuation Hall conductivity and the Hall angle, describing the Hall effect, are calculated for arbitrary value of the imaginary part of the relaxation time in the frame of the time-dependent Ginzburg-Landau theory in type II-superconductor with thermal noise describing strong thermal fluctuations. The self-consistent Gaussian approximation is used to treat the nonlinear interaction term in dynamics. We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. The results are compared with experimental data on high-Tc superconductor.

  10. Homogenization of the Three-dimensional Hall Effect and Change of Sign of the Hall Coefficient

    NASA Astrophysics Data System (ADS)

    Briane, Marc; Milton, Graeme W.

    2009-09-01

    The notion of a Hall matrix associated with a possibly anisotropic conducting material in the presence of a small magnetic field is introduced. Then, for any material having a microstructure we prove a general homogenization result satisfied by the Hall matrix in the framework of the H-convergence of Murat-Tartar. Extending a result of Bergman, we show that the Hall matrix can be computed from the corrector associated with the homogenization problem when no magnetic field is present. Finally, we give an example of a microstructure for which the Hall matrix is positive isotropic almost everywhere, while the homogenized Hall matrix is negative isotropic.

  11. Advanced Glycation End-Products Enhance Lung Cancer Cell Invasion and Migration.

    PubMed

    Hsia, Te-Chun; Yin, Mei-Chin; Mong, Mei-Chin

    2016-01-01

    Effects of carboxymethyllysine (CML) and pentosidine, two advanced glycation end-products (AGEs), upon invasion and migration in A549 and Calu-6 cells, two non-small cell lung cancer (NSCLC) cell lines were examined. CML or pentosidine at 1, 2, 4, 8 or 16 μmol/L were added into cells. Proliferation, invasion and migration were measured. CML or pentosidine at 4-16 μmol/L promoted invasion and migration in both cell lines, and increased the production of reactive oxygen species, tumor necrosis factor-α, interleukin-6 and transforming growth factor-β1. CML or pentosidine at 2-16 μmol/L up-regulated the protein expression of AGE receptor, p47(phox), intercellular adhesion molecule-1 and fibronectin in test NSCLC cells. Matrix metalloproteinase-2 protein expression in A549 and Calu-6 cells was increased by CML or pentosidine at 4-16 μmol/L. These two AGEs at 2-16 μmol/L enhanced nuclear factor κ-B (NF-κ B) p65 protein expression and p38 phosphorylation in A549 cells. However, CML or pentosidine at 4-16 μmol/L up-regulated NF-κB p65 and p-p38 protein expression in Calu-6 cells. These findings suggest that CML and pentosidine, by promoting the invasion, migration and production of associated factors, benefit NSCLC metastasis. PMID:27517907

  12. Advanced Glycation End-Products Enhance Lung Cancer Cell Invasion and Migration

    PubMed Central

    Hsia, Te-Chun; Yin, Mei-Chin; Mong, Mei-Chin

    2016-01-01

    Effects of carboxymethyllysine (CML) and pentosidine, two advanced glycation end-products (AGEs), upon invasion and migration in A549 and Calu-6 cells, two non-small cell lung cancer (NSCLC) cell lines were examined. CML or pentosidine at 1, 2, 4, 8 or 16 μmol/L were added into cells. Proliferation, invasion and migration were measured. CML or pentosidine at 4–16 μmol/L promoted invasion and migration in both cell lines, and increased the production of reactive oxygen species, tumor necrosis factor-α, interleukin-6 and transforming growth factor-β1. CML or pentosidine at 2–16 μmol/L up-regulated the protein expression of AGE receptor, p47phox, intercellular adhesion molecule-1 and fibronectin in test NSCLC cells. Matrix metalloproteinase-2 protein expression in A549 and Calu-6 cells was increased by CML or pentosidine at 4–16 μmol/L. These two AGEs at 2–16 μmol/L enhanced nuclear factor κ-B (NF-κ B) p65 protein expression and p38 phosphorylation in A549 cells. However, CML or pentosidine at 4–16 μmol/L up-regulated NF-κB p65 and p-p38 protein expression in Calu-6 cells. These findings suggest that CML and pentosidine, by promoting the invasion, migration and production of associated factors, benefit NSCLC metastasis. PMID:27517907

  13. Helicobacter pylori infection induced gastric cancer; advance in gastric stem cell research and the remaining challenges

    PubMed Central

    2012-01-01

    Helicobacter pylori infection is the major cause of gastric cancer, which remains an important health care challenge. Recent investigation in gastric stem cell or progenitor cell biology has uncovered valuable information in understanding the gastric gland renewal and maintenance of homeostasis, they also provide clues for further defining the mechanisms by which gastric cancer may originate and progress. Lgr5, Villin-promoter, TFF2-mRNA and Mist have recently been identified as gastric stem/progenitor cell markers; their identification enriched our understanding on the gastric stem cell pathobiology during chronic inflammation and metaplasia. In addition, advance in gastric cancer stem cell markers such as CD44, CD90, CD133, Musashi-1 reveal novel information on tumor cell behavior and disease progression implicated for therapeutics. However, two critical questions remain to be of considerable challenges for future exploration; one is how H. pylori or chronic inflammation affects gastric stem cell or their progenitors, which give rise to mucus-, acid-, pepsinogen-, and hormone-secreting cell lineages. Another one is how bacterial infection or inflammation induces oncogenic transformation and propagates into tumors. Focus on the interactions of H. pylori with gastric stem/progenitor cells and their microenvironment will be instrumental to decipher the initiation and origin of gastric cancer. Future studies in these areas will be critical to uncover molecular mechanisms of chronic inflammation-mediated oncogenic transformation and provide options for cancer prevention and intervention. We review recent progress and discuss future research directions in these important research fields. PMID:23217022

  14. The CD133+ cell as advanced medicinal product for myocardial and limb ischemia.

    PubMed

    Bongiovanni, Dario; Bassetti, Beatrice; Gambini, Elisa; Gaipa, Giuseppe; Frati, Giacomo; Achilli, Felice; Scacciatella, Paolo; Carbucicchio, Corrado; Pompilio, Giulio

    2014-10-15

    Ischemic diseases are the major cause of death and morbidity in Western countries. In the last decade, cell therapy has been suggested to be a promising treatment both in acute/chronic myocardial and peripheral ischemia. Different cell lineages have been tested, including endothelial progenitor cells. A subpopulation of bone marrow-derived immature ECPs, expressing the highly conserved stem cell glycoprotein antigen prominin-1 or CD133 marker, was shown to possess pro-angiogenic and antiapoptotic effects on ischemic tissues. The mechanisms implicated in CD133+ cells ability to contribute to neovascularization processes have been attributed to their ability to directly differentiate into newly forming vessels and to indirectly activate pro-angiogenic signaling by paracrine mechanisms. A large body of in vivo experimental evidences has demonstrated the potential of CD133+ cells to reverse ischemia. Moreover, several clinical trials have reported promising beneficial effects after infusion of autologous CD133+ into ischemic heart and limbs exploiting various delivery strategies. These trials have contributed to characterize the CD133+ manufacturing process as an advanced cell product (AMP). The aim of this review is to summarize available experimental and clinical data on CD133+ cells in the context of myocardial and peripheral ischemia, and to focus on the development of the CD133+ cell as an anti-ischemic AMP.

  15. Dynamic assessment of Amyloid oligomers - cell membrane interaction by advanced impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Gheorghiu, M.; David, S.; Polonschii, C.; Bratu, D.; Gheorghiu, E.

    2013-04-01

    The amyloid β (Aβ) peptides are believed to be pivotal in Alzheimer's disease (AD) pathogenesis and onset of vascular dysfunction. Recent studies indicate that Aβ1-42 treatment influences the expression of tight junction protein complexes, stress fibre formation, disruption and aggregation of actin filaments and cellular gap formation. Aiming for functional characterization of model cells upon Aβ1-42 treatment, we deployed an advanced Electric Cell-substrate Impedance Sensing for monitoring cell evolution. A precision Impedance Analyzer with a multiplexing module developed in house was used for recording individual electrode sets in the 40 Hz - 100 KHz frequency range. In a step forward from the classical ECIS assays, we report on a novel data analysis algorithm that enables access to cellular and paracellular electrical parameters and cell surface interaction with fully developed cell monolayers. The evolution of the impedance at selected frequencies provides evidence for a dual effect of Aβ42 exposure, at both paracellular permeability and cell adherence level, with intricate dynamics that open up new perspectives on Aβ1-42 oligomers - cell membrane interaction. Validation of electrical impedance assays of the amyloid fibrils effect on cell membrane structure is achieved by both AFM analysis and Surface Plasmon Resonance studies. The capabilities of this noninvasive, real time platform for cell analysis in a wider applicative context are outlined.

  16. Cost-Effectiveness of Cetuximab for Advanced Esophageal Squamous Cell Carcinoma

    PubMed Central

    Bruno, Marco J.; Polinder, Suzanne; Lorenzen, Sylvie; Lordick, Florian; Peppelenbosch, Maikel P.; Spaander, Manon C. W.

    2016-01-01

    Background Costly biologicals in palliative oncology are emerging at a rapid pace. For example, in patients with advanced esophageal squamous cell carcinoma addition of cetuximab to a palliative chemotherapy regimen appears to improve survival. However, it simultaneously results in higher costs. We aimed to determine the incremental cost-effectiveness ratio of adding cetuximab to first-line chemotherapeutic treatment of patients with advanced esophageal squamous cell carcinoma, based on data from a randomized controlled phase II trial. Methods A cost effectiveness analysis model was applied based on individual patient data. It included only direct medical costs from the health-care perspective. Quality-adjusted life-years and incremental cost-effectiveness ratios were calculated. Sensitivity analysis was performed by a Monte Carlo analysis. Results Adding cetuximab to a cisplatin-5-fluorouracil first-line regimen for advanced esophageal squamous cell carcinoma resulted in an the incremental cost-effectiveness ratio of €252,203 per quality-adjusted life-year. Sensitivity analysis shows that there is a chance of less than 0.001 that the incremental cost-effectiveness ratio will be less than a maximum willingness to pay threshold of €40,000 per quality-adjusted life-year, which is representative for the threshold used in The Netherlands and other developed countries. Conclusions Addition of cetuximab to a cisplatin-5-fluorouracil first-line regimen for advanced esophageal squamous cell carcinoma is not cost-effective when appraised according to currently accepted criteria. Cost-effectiveness analyses using outcome data from early clinical trials (i.c. a phase II trial) enable pharmaceutical companies and policy makers to gain early insight into whether a new drug meets the current eligibility standards for reimbursement and thereby potential admittance for use in regular clinical practice. PMID:27100871

  17. Elementary scaling laws for the design of low and high power hall effect thrusters

    NASA Astrophysics Data System (ADS)

    Dannenmayer, K.; Mazouffre, S.

    2011-10-01

    An advanced set of scaling laws for Hall effect thrusters running with Xenon as propellant is established on the basis of the existence of an optimum atom number density that warrants a high efficiency thruster operation. A set of general relationships between macroscopic quantities, like thrust and input power, dimensions, including the channel length, the channel width and the channel mean diameter, and magnetic field strength are inferred from the main physical processes at work in a Hall thruster discharge. The "atom density constraint" of which the nature is here critically interpreted allows simplifying those relationships as it leads to a linear dependency between the channel length and mean diameter. Scaling laws which represent an essential tool for sizing up and down Hall thrusters are eventually obtained after proportionnality coefficients are determined. This last step is realized by means of a vast database that presently encompasses 33 single-stage Hall thrusters. In order to illustrate the usefulness of this new set of scaling laws, two practical applications are given and discussed. The scaling laws are first employed to calculate the dimensions and the operating parameters for a 20-kilowatt Hall thruster capable of producing 1 N of thrust. Such an electrical engine would permit orbit transfer of large communication satellites. Finally, the geometry of a Hall thruster is determined for tolerating 100 kW, an interesting power level for interplanetary trips.

  18. New and emerging targeted treatments in advanced non-small-cell lung cancer.

    PubMed

    Hirsch, Fred R; Suda, Kenichi; Wiens, Jacinta; Bunn, Paul A

    2016-09-01

    Targeted therapies are substantially changing the management of lung cancers. These treatments include drugs that target driver mutations, those that target presumed important molecules in cancer cell proliferation and survival, and those that inhibit immune checkpoint molecules. This area of research progresses day by day, with novel target discoveries, novel drug development, and use of novel combination treatments. Researchers and clinicians have also extensively investigated the predictive biomarkers and the molecular mechanisms underlying inherent or acquired resistance to these targeted therapies. We review recent progress in the development of targeted treatments for patients with advanced non-small-cell lung cancer, especially focusing on data from published clinical trials. PMID:27598681

  19. Monolithic solid oxide fuel cell technology advancement for coal- based power generation. Quarterly report, December 1991

    SciTech Connect

    Not Available

    1992-01-15

    The program is conducted by a team consisting of AiResearch Los Angeles Division of Allied-Signal Aerospace Company and Argonne National Laboratory (ANL). The objective of the program is to advance materials and fabrication methodologies to develop a monolithic solid oxide fuel cell (MSOFC) system capable of meeting performance, life, and cost goals for coal-based power generation. The program focuses on materials research and development, fabrication process development, cell/stack performance testing and characterization, cost and system analysis, and quality development.

  20. Monolithic solid oxide fuel cell technology advancement for coal- based power generation

    SciTech Connect

    Not Available

    1992-01-15

    The program is conducted by a team consisting of AiResearch Los Angeles Division of Allied-Signal Aerospace Company and Argonne National Laboratory (ANL). The objective of the program is to advance materials and fabrication methodologies to develop a monolithic solid oxide fuel cell (MSOFC) system capable of meeting performance, life, and cost goals for coal-based power generation. The program focuses on materials research and development, fabrication process development, cell/stack performance testing and characterization, cost and system analysis, and quality development.

  1. Recent Advances in Genetic Technique of Microbial Report Cells and Their Applications in Cell Arrays.

    PubMed

    Kim, Do Hyun; Kim, Moon Il; Park, Hyun Gyu

    2015-01-01

    Microbial cell arrays have attracted consistent attention for their ability to provide unique global data on target analytes at low cost, their capacity for readily detectable and robust cell growth in diverse environments, their high degree of convenience, and their capacity for multiplexing via incorporation of molecularly tailored reporter cells. To highlight recent progress in the field of microbial cell arrays, this review discusses research on genetic engineering of reporter cells, technologies for patterning live cells on solid surfaces, cellular immobilization in different polymers, and studies on their application in environmental monitoring, disease diagnostics, and other related fields. On the basis of these results, we discuss current challenges and future prospects for novel microbial cell arrays, which show promise for use as potent tools for unraveling complex biological processes.

  2. Recent Advances in Genetic Technique of Microbial Report Cells and Their Applications in Cell Arrays

    PubMed Central

    Kim, Do Hyun; Kim, Moon Il; Park, Hyun Gyu

    2015-01-01

    Microbial cell arrays have attracted consistent attention for their ability to provide unique global data on target analytes at low cost, their capacity for readily detectable and robust cell growth in diverse environments, their high degree of convenience, and their capacity for multiplexing via incorporation of molecularly tailored reporter cells. To highlight recent progress in the field of microbial cell arrays, this review discusses research on genetic engineering of reporter cells, technologies for patterning live cells on solid surfaces, cellular immobilization in different polymers, and studies on their application in environmental monitoring, disease diagnostics, and other related fields. On the basis of these results, we discuss current challenges and future prospects for novel microbial cell arrays, which show promise for use as potent tools for unraveling complex biological processes. PMID:26436087

  3. Advanced cell therapies: targeting, tracking and actuation of cells with magnetic particles.

    PubMed

    Connell, John J; Patrick, P Stephen; Yu, Yichao; Lythgoe, Mark F; Kalber, Tammy L

    2015-01-01

    Regenerative medicine would greatly benefit from a new platform technology that enabled measurable, controllable and targeting of stem cells to a site of disease or injury in the body. Superparamagnetic iron-oxide nanoparticles offer attractive possibilities in biomedicine and can be incorporated into cells, affording a safe and reliable means of tagging. This review describes three current and emerging methods to enhance regenerative medicine using magnetic particles to guide therapeutic cells to a target organ; track the cells using MRI and assess their spatial localization with high precision and influence the behavior of the cell using magnetic actuation. This approach is complementary to the systemic injection of cell therapies, thus expanding the horizon of stem cell therapeutics.

  4. Mesenchymal Stem Cells in Chronic Wounds: The Spectrum from Basic to Advanced Therapy

    PubMed Central

    Otero-Viñas, Marta; Falanga, Vincent

    2016-01-01

    Significance: Almost 7 million Americans have chronic cutaneous wounds and billions of dollars are spent on their treatment. The number of patients with nonhealing wounds keeps increasing worldwide due to an ever-aging population, increasing number of obese and diabetic patients, and cardiovascular disease. Recent Advances: Advanced treatments for difficult wounds are needed. Therapy with mesenchymal stem cells (MSCs) is attractive due to their differentiating potential, their immunomodulating properties, and their paracrine effects. Critical Issues: New technologies (including growth factors and skin substitutes) are now widely used for stimulating wound healing. However, in spite of these advances, the percentage of complete wound closure in most clinical situations is around 50–60%. Moreover, there is a high rate of wound recurrence. Future Directions: Recently, it has been demonstrated that MSCs speed up wound healing by decreasing inflammation, by promoting angiogenesis, and by decreasing scarring. However, there are some potential limitations to successful MSC therapy. These limitations include the need to improve cell delivery methods, cell viability, heterogeneity in MSC preparations, and suboptimal wound bed preparation. Further large, controlled clinical trials are needed to establish the safety of MSCs before widespread clinical application. PMID:27076993

  5. View of north front and west sides of hall, facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of north front and west sides of hall, facing south - International Longshoremen's & Warehousemen's Union Hall, Naval Civil Engineering Laboratory, Port Hueneme Road, Port Hueneme, Ventura County, CA

  6. Interior detail of dispatch boards in main hall, facing west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior detail of dispatch boards in main hall, facing west - International Longshoremen's & Warehousemen's Union Hall, Naval Civil Engineering Laboratory, Port Hueneme Road, Port Hueneme, Ventura County, CA

  7. Survey of Residence Hall Life at NCSU.

    ERIC Educational Resources Information Center

    Dolin, Nancy C.

    A 1977 North Carolina State University survey of a sample of on-campus students determined their attitudes toward residence hall activities, facilities, and staff. Information is shown by sex, class, and residence hall, and totals are weighted to reflect actual proportions in each dorm. Among the findings are the following: cookouts, movies, beer…

  8. Metal-Film Hall-Effect Devices

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.

    1994-01-01

    Large positive and negative Hall coefficients achievable. Family of Hall-effect devices made from multilayer metal films instead of semiconductor materials. Metal films easier to fabricate; formed by deposition on variety of substrates, and leads readily attached to them. Fabricated with larger areas, potentially more reliable, and less affected by impurities. Also used to measure magnetic fields. Devices especially useful at low temperatures.

  9. Concert Halls of Chicago Under Theodore Thomas.

    ERIC Educational Resources Information Center

    Olsen, Dale A.

    1983-01-01

    Describes the musical history of Chicago, which culminated in the creation of the Chicago Symphony and the construction of Orchestra Hall. Theodore Thomas spent 30 years introducing Chicagoans to symphonic music. He founded the Chicago Symphony and, in 1904, led the first concert in Orchestra Hall. (CS)

  10. 19th Annual Residence Hall Construction Report

    ERIC Educational Resources Information Center

    Agron, Joe

    2008-01-01

    The construction of residence hall facilities at colleges and universities continues to be strong, as institutions scramble to meet the housing needs and varied demands of a growing student population. This article presents data collected from 39 new residence hall projects completed in 2007. According to American School & University's 19th annual…

  11. 20th Annual Residence Hall Construction Report

    ERIC Educational Resources Information Center

    Agron, Joe

    2009-01-01

    Even in difficult economic times, colleges and universities continue to invest in residence hall construction projects as a way to attract new students and keep existing ones on campus. According to data from "American School & University"'s 20th annual Residence Hall Construction Report, the median new project completed in 2008 was less expensive…

  12. Training Top 10 Hall of Fame

    ERIC Educational Resources Information Center

    Training, 2012

    2012-01-01

    Microsoft Corporation and SCC Soft Computer are the newest inductees into the Training Top 10 Hall of Fame, joining the ranks of the 11 companies named to the hall since its inception in 2008 (Wyeth Pharmaceuticals subsequently was acquired by Pfizer Inc. in 2009). These 11 companies held Top 10 spots in the Training Top 50, Top 100, and now Top…

  13. The Scientific Humanism of G. Stanley Hall

    ERIC Educational Resources Information Center

    Meyer, Donald H.

    1971-01-01

    This paper presents the humanistic psychology of the pioneer American psychologist Granville Stanley Hall (1844-1924), examining Hall's effort to develop a system of psychology that is at once rigorously scientific and, simultaneously, capable of verifying essential human values. (Author)

  14. Sport for All. Low Cost Sports Halls.

    ERIC Educational Resources Information Center

    Council of Europe, Strasbourg (France).

    This report of the conference on low-cost sports halls, sponsored by the Council of Europe, is divided into two sections: technical studies and conclusions. The introduction to the report provides an overview of the long-term program of the Council of Europe with regard to sport for all and a discussion of multipurpose sports halls. Sociocultural,…

  15. Quantum Hall effect in quantum electrodynamics

    SciTech Connect

    Penin, Alexander A.

    2009-03-15

    We consider the quantum Hall effect in quantum electrodynamics and find a deviation from the quantum-mechanical prediction for the Hall conductivity due to radiative antiscreening of electric charge in an external magnetic field. A weak dependence of the universal von Klitzing constant on the magnetic field strength, which can possibly be observed in a dedicated experiment, is predicted.

  16. Screening system of blocking agents of the receptor for advanced glycation endproducts in cells using fluorescence.

    PubMed

    Jung, Dong Ho; Kim, Young Sook; Kim, Jin Sook

    2012-01-01

    Activation of the receptor for advanced glycation endproducts (RAGE) triggers cellular responses implicated in the pathogenesis of diabetic complications; blockade of RAGE has been shown to inhibit the development of diabetic complications. To develop a screening system to identify novel disruptors of advanced glycation endproducts (AGE)-RAGE binding, we used an AGE-RAGE binding system in RAGE-overexpressing cells; test compounds were screened using this system. To construct human RAGE-overexpressing cells, mouse mesangial cells (MMCs) were stably transfected with the pcDNA-human RAGE (hRAGE) vector and selected under 1 mg/mL gentamicin (G418). RAGE expression in hRAGE-overexpressing MMCs was analyzed by Western blotting with specific RAGE antibody. To identify novel disruptors of AGE-RAGE binding, 50 single compounds and AGE-bovine serum albumin (BSA)-Alexa 488 (AGE-BSA labeled with Alexa 488) were treated to the hRAGE-overexpressing MMCs. Nonbinding AGE-BSA-Alexa 488 was washed and fluorescence measured by microtiter plate reader (excitation wavelength, 485 nm; emission wavelength, 528 nm). In hRAGE-overexpressing cells, only treatment with AGE-BSA-Alexa 488 significantly increased fluorescence intensity in a dose-dependent manner. Of 50 compounds tested, genistein disrupted AGE-RAGE binding in a dose-dependent manner. This AGE-RAGE binding system using AGE-BSA-Alexa 488 in hRAGE-overexpressing cells was suitable for screening of agents that disrupt AGE-hRAGE binding.

  17. Screening system of blocking agents of the receptor for advanced glycation endproducts in cells using fluorescence.

    PubMed

    Jung, Dong Ho; Kim, Young Sook; Kim, Jin Sook

    2012-01-01

    Activation of the receptor for advanced glycation endproducts (RAGE) triggers cellular responses implicated in the pathogenesis of diabetic complications; blockade of RAGE has been shown to inhibit the development of diabetic complications. To develop a screening system to identify novel disruptors of advanced glycation endproducts (AGE)-RAGE binding, we used an AGE-RAGE binding system in RAGE-overexpressing cells; test compounds were screened using this system. To construct human RAGE-overexpressing cells, mouse mesangial cells (MMCs) were stably transfected with the pcDNA-human RAGE (hRAGE) vector and selected under 1 mg/mL gentamicin (G418). RAGE expression in hRAGE-overexpressing MMCs was analyzed by Western blotting with specific RAGE antibody. To identify novel disruptors of AGE-RAGE binding, 50 single compounds and AGE-bovine serum albumin (BSA)-Alexa 488 (AGE-BSA labeled with Alexa 488) were treated to the hRAGE-overexpressing MMCs. Nonbinding AGE-BSA-Alexa 488 was washed and fluorescence measured by microtiter plate reader (excitation wavelength, 485 nm; emission wavelength, 528 nm). In hRAGE-overexpressing cells, only treatment with AGE-BSA-Alexa 488 significantly increased fluorescence intensity in a dose-dependent manner. Of 50 compounds tested, genistein disrupted AGE-RAGE binding in a dose-dependent manner. This AGE-RAGE binding system using AGE-BSA-Alexa 488 in hRAGE-overexpressing cells was suitable for screening of agents that disrupt AGE-hRAGE binding. PMID:23037172

  18. Initial performance of advanced designs for IPV nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.; Manzo, M. A.; Gonzalez-Sanabria, O. D.

    1985-01-01

    Advanced designs for individual pressure vessel nickel hydrogen cells were conceived which should improve the life cycle at deep depths of discharge and improve thermal management. Features of the designs which are new and not incorporated in either of the contemporary cells (Air Force/Hughes, Comsat) are: (1) the use of alternate methods of oxygen recombination, (2) use of serrated edge separators to facilitate movement of gas within the cell while still maintaining required physical contact with the wall wick, and (3) use of an expandable stack to accommodate some of the nickel electrode expansion. The designs also consider electrolyte volume requirements over the life of the cells, and are fully compatible with the Air Force/Hughes design.

  19. Initial performance of advanced designs for IPV nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.

    1986-01-01

    Advanced designs for individual pressure vessel nickel-hydrogen cells have been conceived which should improve the cycle life at deep depths-of-discharge and improve thermal management. Features of the designs which are new and not incorporated in either of the contemporary cells (Air Force/Hughes, Comsat) are: (1) use of alternate methods of oxygen recombination, (2) use of serrated edge separators to facilitate movement of gas within the cell while still maintaining required physical contact with the wall wick, and (3) use of an expandable stack to accommodate some of the nickel electrode expansion. The designs also consider electrolyte volume requirements over the life of the cells, and are fully compatible with the Air Force/Hughes design.

  20. Advances in microfluidic platforms for analyzing and regulating human pluripotent stem cells.

    PubMed

    Qian, Tongcheng; Shusta, Eric V; Palecek, Sean P

    2015-10-01

    Microfluidic devices employ submillimeter length scale control of flow to achieve high-resolution spatial and temporal control over the microenvironment, providing powerful tools to elucidate mechanisms of human pluripotent stem cell (hPSC) regulation and to elicit desired hPSC fates. In addition, microfluidics allow control of paracrine and juxtracrine signaling, thereby enabling fabrication of microphysiological systems comprised of multiple cell types organized into organs-on-a-chip. Microfluidic cell culture systems can also be integrated with actuators and sensors, permitting construction of high-density arrays of cell-based biosensors for screening applications. This review describes recent advances in using microfluidics to understand mechanisms by which the microenvironment regulates hPSC fates and applications of microfluidics to realize the potential of hPSCs for in vitro modeling and screening applications.

  1. Smaller, faster, brighter: advances in optical imaging of living plant cells.

    PubMed

    Shaw, Sidney L; Ehrhardt, David W

    2013-01-01

    The advent of fluorescent proteins and access to modern imaging technologies have dramatically accelerated the pace of discovery in plant cell biology. Remarkable new insights into such diverse areas as plant pathogenesis, cytoskeletal dynamics, sugar transport, cell wall synthesis, secretory control, and hormone signaling have come from careful examination of living cells using advanced optical probes. New technologies, both commercially available and on the horizon, promise a continued march toward more quantitative methods for imaging and for extending the optical exploration of biological structure and activity to molecular scales. In this review, we lay out fundamental issues in imaging plant specimens and look ahead to several technological innovations in molecular tools, instrumentation, imaging methods, and specimen handling that show promise for shaping the coming era of plant cell biology.

  2. ADVANCED CHINESE. YALE LINGUISTIC SERIES.

    ERIC Educational Resources Information Center

    DE FRANCIS, JOHN; AND OTHERS

    THE THIRD IN A SERIES OF TEXTS PREPARED AT SETON HALL UNIVERSITY, THIS ADVANCED TEXT PRESUPPOSES MASTERY OF "BEGINNING CHINESE,""BEGINNING CHINESE READER," AND LESSONS 1 TO 6 OF "INTERMEDIATE CHINESE READER." A COMPANION VOLUME TO THIS ONE, "CHARACTER TEXT FOR ADVANCED CHINESE," PROVIDES READING PRACTICE AND REPETITION OF THE 904 NEW CHARACTERS…

  3. Flexible Hall sensors based on graphene

    NASA Astrophysics Data System (ADS)

    Wang, Zhenxing; Shaygan, Mehrdad; Otto, Martin; Schall, Daniel; Neumaier, Daniel

    2016-03-01

    The excellent electronic and mechanical properties of graphene provide a perfect basis for high performance flexible electronic and sensor devices. Here, we present the fabrication and characterization of flexible graphene based Hall sensors. The Hall sensors are fabricated on 50 μm thick flexible Kapton foil using large scale graphene grown by chemical vapor deposition technique on copper foil. Voltage and current normalized sensitivities of up to 0.096 V VT-1 and 79 V AT-1 were measured, respectively. These values are comparable to the sensitivity of rigid silicon based Hall sensors and are the highest values reported so far for any flexible Hall sensor devices. The sensitivity of the Hall sensor shows no degradation after being bent to a minimum radius of 4 mm, which corresponds to a tensile strain of 0.6%, and after 1000 bending cycles to a radius of 5 mm.

  4. Flexible Hall sensors based on graphene.

    PubMed

    Wang, Zhenxing; Shaygan, Mehrdad; Otto, Martin; Schall, Daniel; Neumaier, Daniel

    2016-04-14

    The excellent electronic and mechanical properties of graphene provide a perfect basis for high performance flexible electronic and sensor devices. Here, we present the fabrication and characterization of flexible graphene based Hall sensors. The Hall sensors are fabricated on 50 μm thick flexible Kapton foil using large scale graphene grown by chemical vapor deposition technique on copper foil. Voltage and current normalized sensitivities of up to 0.096 V VT(-1) and 79 V AT(-1) were measured, respectively. These values are comparable to the sensitivity of rigid silicon based Hall sensors and are the highest values reported so far for any flexible Hall sensor devices. The sensitivity of the Hall sensor shows no degradation after being bent to a minimum radius of 4 mm, which corresponds to a tensile strain of 0.6%, and after 1000 bending cycles to a radius of 5 mm.

  5. Advances in inducing adaptive immunity using cell-based cancer vaccines: Clinical applications in pancreatic cancer.

    PubMed

    Kajihara, Mikio; Takakura, Kazuki; Kanai, Tomoya; Ito, Zensho; Matsumoto, Yoshihiro; Shimodaira, Shigetaka; Okamoto, Masato; Ohkusa, Toshifumi; Koido, Shigeo

    2016-05-14

    The incidence of pancreatic ductal adenocarcinoma (PDA) is on the rise, and the prognosis is extremely poor because PDA is highly aggressive and notoriously difficult to treat. Although gemcitabine- or 5-fluorouracil-based chemotherapy is typically offered as a standard of care, most patients do not survive longer than 1 year. Therefore, the development of alternative therapeutic approaches for patients with PDA is imperative. As PDA cells express numerous tumor-associated antigens that are suitable vaccine targets, one promising treatment approach is cancer vaccines. During the last few decades, cell-based cancer vaccines have offered encouraging results in preclinical studies. Cell-based cancer vaccines are mainly generated by presenting whole tumor cells or dendritic cells to cells of the immune system. In particular, several clinical trials have explored cell-based cancer vaccines as a promising therapeutic approach for patients with PDA. Moreover, chemotherapy and cancer vaccines can synergize to result in increased efficacies in patients with PDA. In this review, we will discuss both the effect of cell-based cancer vaccines and advances in terms of future strategies of cancer vaccines for the treatment of PDA patients. PMID:27182156

  6. Advances in inducing adaptive immunity using cell-based cancer vaccines: Clinical applications in pancreatic cancer

    PubMed Central

    Kajihara, Mikio; Takakura, Kazuki; Kanai, Tomoya; Ito, Zensho; Matsumoto, Yoshihiro; Shimodaira, Shigetaka; Okamoto, Masato; Ohkusa, Toshifumi; Koido, Shigeo

    2016-01-01

    The incidence of pancreatic ductal adenocarcinoma (PDA) is on the rise, and the prognosis is extremely poor because PDA is highly aggressive and notoriously difficult to treat. Although gemcitabine- or 5-fluorouracil-based chemotherapy is typically offered as a standard of care, most patients do not survive longer than 1 year. Therefore, the development of alternative therapeutic approaches for patients with PDA is imperative. As PDA cells express numerous tumor-associated antigens that are suitable vaccine targets, one promising treatment approach is cancer vaccines. During the last few decades, cell-based cancer vaccines have offered encouraging results in preclinical studies. Cell-based cancer vaccines are mainly generated by presenting whole tumor cells or dendritic cells to cells of the immune system. In particular, several clinical trials have explored cell-based cancer vaccines as a promising therapeutic approach for patients with PDA. Moreover, chemotherapy and cancer vaccines can synergize to result in increased efficacies in patients with PDA. In this review, we will discuss both the effect of cell-based cancer vaccines and advances in terms of future strategies of cancer vaccines for the treatment of PDA patients. PMID:27182156

  7. Hepatocyte growth factor protects human endothelial cells against advanced glycation end products-induced apoposis

    SciTech Connect

    Zhou Yijun . E-mail: zhou-yijun@hotmail.com; Wang Jiahe; Zhang Jin

    2006-06-02

    Advanced glycation end products (AGEs) form by a non-enzymatic reaction between reducing sugars and biological proteins, which play an important role in the pathogenesis of atherosclerosis. In this study, we assessed AGEs effects on human umbilical vein endothelial cells (HUVECs) growth, proliferation and apoptosis. Additionally, we investigated whether hepatocyte growth factor (HGF), an anti-apoptotic factor for endothelial cells, prevents AGEs-induced apoptosis of HUVECs. HUVECs were treated with AGEs in the presence or absence of HGF. Treatment of HUVECs with AGEs changed cell morphology, decreased cell viability, and induced DNA fragmentation, leading to apoptosis. Apoptosis was induced by AGEs in a dose- and time-dependent fashion. AGEs markedly elevated Bax and decreased NF-{kappa}B, but not Bcl-2 expression. Additionally, AGEs significantly inhibited cell growth through a pro-apoptotic action involving caspase-3 and -9 activations in HUVECs. Most importantly, pretreatment with HGF protected against AGEs-induced cytotoxicity in the endothelial cells. HGF significantly promoted the expression of Bcl-2 and NF-{kappa}B, while decreasing the activities of caspase-3 and -9 without affecting Bax level. Our data suggest that AGEs induce apoptosis in endothelial cells. HGF effectively attenuate AGEs-induced endothelial cell apoptosis. These findings provide new perspectives in the role of HGF in cardiovascular disease.

  8. Recent advances on enzymatic glucose/oxygen and hydrogen/oxygen biofuel cells: Achievements and limitations

    NASA Astrophysics Data System (ADS)

    Cosnier, Serge; Gross, Andrew J.; Le Goff, Alan; Holzinger, Michael

    2016-09-01

    The possibility of producing electrical power from chemical energy with biological catalysts has induced the development of biofuel cells as viable energy sources for powering portable and implanted electronic devices. These power sources employ biocatalysts, called enzymes, which are highly specific and catalytic towards the oxidation of a biofuel and the reduction of oxygen or hydrogen peroxide. Enzymes, on one hand, are promising candidates to replace expensive noble metal-based catalysts in fuel cell research. On the other hand, they offer the exciting prospect of a new generation of fuel cells which harvest energy from body fluids. Biofuel cells which use glucose as a fuel are particularly interesting for generating electricity to power electronic devices inside a living body. Hydrogen consuming biofuel cells represent an emerging alternative to platinum catalysts due to comparable efficiencies and the capability to operate at lower temperatures. Currently, these technologies are not competitive with existing commercialised fuel cell devices due to limitations including insufficient power outputs and lifetimes. The advantages and challenges facing glucose biofuel cells for implantation and hydrogen biofuel cells will be summarised along with recent promising advances and the future prospects of these exotic energy-harvesting devices.

  9. Evaluation of Low Power Hall Thruster Propulsion

    NASA Technical Reports Server (NTRS)

    Manzella, David; Oleson, Steve; Sankovic, John; Haag, Tom; Semenkin, Alexander; Kim, Vladimir

    1996-01-01

    Hall thruster systems based on the SPT-50 and the TAL D-38 were evaluated and mission studies were performed. The 0.3 kilowatt SPT-50 operated with a specific impulse of 1160 seconds and an efficiency of 0.32. The 0.8 kilowatt D-38 provided a specific impulse above 1700 seconds at an efficiency of 0.5. The D-38 system was shown to offer a 56 kilogram propulsion system mass savings over a 101 kilogram hydrazine monopropellant system designed to perform North-South station keeping maneuvers on board a 430 kilogram geostationary satellite. The SPIT-50 system offered a greater than 50% propulsion system mass reduction in comparison to the chemical system on board a 200 kilogram low Earth orbit spacecraft performing two orbit raises and drag makeup over two years. The performance characteristics of the SPF-50 were experimentally evaluated at a number of operating conditions. The ion current density distribution of this engine was measured. The performance and system mass benefits of advanced systems based on both engines were considered.

  10. Quantum Spin Hall Effect in Ultrasonic Metamaterials

    NASA Astrophysics Data System (ADS)

    Mousavi, S. Hossein; Khanikaev, Alexander B.; Wang, Zheng

    2015-03-01

    The discovery of topological order without breaking time-reversal symmetry, such as that in Quantum Spin Hall (QSH) effect and Topological Insulators, is one of the most groundbreaking advancements of recent years in condensed matters physics. The approach to topological order without breaking time-reversal symmetry is particularly important in elastics because no natural elastic materials show linear nonreciprocal response. Here we illustrate the first elastic-wave system emulating QSH effect and demonstrate existence of topologically protected elastic edge states. The system represents an elastic metamaterial-based phononic crystal. In this crystal, we achieved degenerate linear dispersion for two sets of modes, classified by one of the system's symmetries. Then, by relaxing and removing that symmetry by deliberately engineering a gauge field emulating a strong spin-orbit coupling of QSH, we observe opening a complete topological bandgap. Finally, the hallmark of the topological order, namely the presence of one-way chiral edge waves insensitive to nonmagnetic defects and disorders, is demonstrated in such elastic metacrystals. We illustrate the unique property of these elastic edge waves to flow around sharp corners without back-reflection or localization.

  11. Advances in the theory and application of BSF cells. [Back Surface Field solar cells

    NASA Technical Reports Server (NTRS)

    Mandelkorn, J.; Lamneck, J. H.

    1975-01-01

    A study to determine the influence of fabrication processes and bulk material properties on the behavior of back surface field (BSF) cells is reported. It is concluded that a photovoltage is generated at the p(+), p back junction of the cell. The concept of majority carrier collection is proposed as a possible mechanism for this generation. Advantages accruing to the advent of BSF cells are outlined.

  12. Single String Integration Test of the High Voltage Hall Accelerator System

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Haag, Thomas W.; Huang, Wensheng; Pinero, Luis; Peterson, Todd; Shastry, Rohit

    2013-01-01

    HiVHAc Task Objectives:-Develop and demonstrate low-power, long-life Hall thruster technology to enable cost effective EP for Discovery-class missions-Advance the TRL level of potential power processing units and xenon feed systems to integrate with the HiVHAc thruster.

  13. Advanced Dependent Pressure Vessel (DPV) nickel-hydrogen spacecraft cell and battery design

    NASA Technical Reports Server (NTRS)

    Coates, Dwaine; Wright, Doug; Repplinger, Ron

    1995-01-01

    The dependent pressure vessel (DPV) nickel-hydrogen (NiH2) battery is being developed as a potential spacecraft battery design for both military and commercial satellites. Individual pressure vessel (IPV) NiH2 batteries are currently flying on more than 70 Earth orbital satellites and have accumulated more than 140,000,000 cell-hours in actual spacecraft operation. The limitations of standard NiH2 IPV flight battery technology are primarily related to the internal cell design and the battery packaging issues associated with grouping multiple cylindrical cells. The DPV cell design offers higher specific energy and reduced cost, while retaining the established IPV NiH2 technology flight heritage and database. The advanced cell design offers a more efficient mechanical, electrical and thermal cell configuration and a reduced parts count. The internal electrode stack is a prismatic flat-plate arrangement. The flat individual cell pressure vessel provides a maximum direct thermal path for removing heat from the electrode stack. The cell geometry also minimizes multiple-cell battery packaging constraints by using an established end-plateltie-rod battery design. A major design advantage is that the battery support structure is efficiently required to restrain only the force applied to a portion of the end cell. As the cells are stacked in series to achieve the desired system voltage, this increment of the total battery weight becomes small. The geometry of the DPV cell promotes compact, minimum volume packaging and places all cell terminals along the length of the battery. The resulting ability to minimize intercell wiring offers additional design simplicity and significant weight savings. The DPV battery design offers significant cost and weight savings advantages while providing minimal design risks. Cell and battery level design issues will be addressed including mechanical, electrical and thermal design aspects. A design performance analysis will be presented at both

  14. Development of advanced therapies in Italy: Management models and sustainability in six Italian cell factories.

    PubMed

    Gaipa, Giuseppe; Introna, Martino; Golay, Josee; Nolli, Maria Luisa; Vallanti, Giuliana; Parati, Eugenio; Giordano, Rosaria; Romagnoli, Luca; Melazzini, Mario; Biondi, Andrea; Biagi, Ettore

    2016-04-01

    On November 10, 2014, the representatives of all six certified Good Manufacturing Practices (GMP) cell factories operating in the Lombardy Region of Italy convened a 1-day workshop in Milan titled "Management Models for the Development And Sustainability of Cell Factories: Public-Private Partnership?" The speakers and panelists addressed not only the many scientific, technological and cultural challenges faced by Lombardy Cell Factories, but also the potential impact of advanced therapy medicinal products (ATMPs) on public health and the role played by translational research in this process. Future perspectives for research and development (R&D) and manufacturing processes in the field of regenerative medicine were discussed as well. This report summarizes the most important issues raised by the workshop participants with particular emphasis on strengths and limitations of the R&D and manufacturing processes for innovative therapeutics in Lombardy and what can be improved in this context while maintaining GMP standards. The participants highlighted several strategies to translate patient-specific advanced therapeutics into scaled manufacturing products for clinical application. These included (i) the development of a synergistic interaction between public and private institutions, (ii) better integration with Italian regulatory agencies and (iii) the creation of a network among Lombardy cell factories and other Italian and European institutions.

  15. Development of advanced therapies in Italy: Management models and sustainability in six Italian cell factories.

    PubMed

    Gaipa, Giuseppe; Introna, Martino; Golay, Josee; Nolli, Maria Luisa; Vallanti, Giuliana; Parati, Eugenio; Giordano, Rosaria; Romagnoli, Luca; Melazzini, Mario; Biondi, Andrea; Biagi, Ettore

    2016-04-01

    On November 10, 2014, the representatives of all six certified Good Manufacturing Practices (GMP) cell factories operating in the Lombardy Region of Italy convened a 1-day workshop in Milan titled "Management Models for the Development And Sustainability of Cell Factories: Public-Private Partnership?" The speakers and panelists addressed not only the many scientific, technological and cultural challenges faced by Lombardy Cell Factories, but also the potential impact of advanced therapy medicinal products (ATMPs) on public health and the role played by translational research in this process. Future perspectives for research and development (R&D) and manufacturing processes in the field of regenerative medicine were discussed as well. This report summarizes the most important issues raised by the workshop participants with particular emphasis on strengths and limitations of the R&D and manufacturing processes for innovative therapeutics in Lombardy and what can be improved in this context while maintaining GMP standards. The participants highlighted several strategies to translate patient-specific advanced therapeutics into scaled manufacturing products for clinical application. These included (i) the development of a synergistic interaction between public and private institutions, (ii) better integration with Italian regulatory agencies and (iii) the creation of a network among Lombardy cell factories and other Italian and European institutions. PMID:26971677

  16. Recent advances in the treatment of adult T-cell leukemia-lymphomas

    PubMed Central

    Utsunomiya, Atae; Choi, Ilseung; Chihara, Dai; Seto, Masao

    2015-01-01

    Recent advances in treatment for adult T-cell leukemia-lymphoma (ATL) are reviewed herein. It is currently possible to select a therapeutic strategy for ATL and predict prognosis by classification of patients by clinical subtypes and clinicopathological factors. Although the overall survival (OS) of patients with ATL has increased marginally because of advances in chemotherapy, further prolongation of survival might be difficult with conventional chemotherapy alone. Promising results have been reported for antiviral therapy using zidovudine and interferon-α, and, indeed, antiviral therapy is currently the standard treatment for patients with ATL in western countries. Remarkably, the 5-year OS rates are 100% for both the smoldering-type and chronic-type ATL. Recently, treatments for ATL have included allogeneic hematopoietic stem cell transplantation and molecular targeted therapies. Furthermore, the anti-CCR4 monoclonal antibody mogamulizumab has been shown to have marked cytotoxic effects on ATL cells, especially in the leukemic type of ATL. In the lymphoma type of ATL, the response rate may be improved by combining mogamulizumab with chemotherapy. It should be recognized that prevention of infection from carriers of human T-cell leukemia virus type-I and transfer of the virus from mother to infant are crucial issues for the eradication of ATL. PMID:25613789

  17. Effect of taurine on advanced glycation end products-induced hypertrophy in renal tubular epithelial cells

    SciTech Connect

    Huang, J.-S. Chuang, L.-Y.; Guh, J.-Y.; Yang, Y.-L.; Hsu, M.-S.

    2008-12-01

    Mounting evidence indicates that advanced glycation end products (AGE) play a major role in the development of diabetic nephropathy (DN). Taurine is a well documented antioxidant agent. To explore whether taurine was linked to altered AGE-mediated renal tubulointerstitial fibrosis in DN, we examined the molecular mechanisms of taurine responsible for inhibition of AGE-induced hypertrophy in renal tubular epithelial cells. We found that AGE (but not non-glycated BSA) caused inhibition of cellular mitogenesis rather than cell death by either necrosis or apoptosis. There were no changes in caspase 3 activity, bcl-2 protein expression, and mitochondrial cytochrome c release in BSA, AGE, or the antioxidant taurine treatments in these cells. AGE-induced the Raf-1/extracellular signal-regulated kinase (ERK) activation was markedly blocked by taurine. Furthermore, taurine, the Raf-1 kinase inhibitor GW5074, and the ERK kinase inhibitor PD98059 may have the ability to induce cellular proliferation and cell cycle progression from AGE-treated cells. The ability of taurine, GW5074, or PD98059 to inhibit AGE-induced hypertrophy was verified by the observation that it significantly decreased cell size, cellular hypertrophy index, and protein levels of RAGE, p27{sup Kip1}, collagen IV, and fibronectin. The results obtained in this study suggest that taurine may serve as the potential anti-fibrotic activity in DN through mechanism dependent of its Raf-1/ERK inactivation in AGE-induced hypertrophy in renal tubular epithelial cells.

  18. Pluripotent stem cell derivation and differentiation toward cardiac muscle: novel techniques and advances in patent literature.

    PubMed

    Quattrocelli, Mattia; Thorrez, Lieven; Sampaolesi, Maurilio

    2013-04-01

    Pluripotent stem cells hold unprecedented potential for regenerative medicine, disease modeling and drug screening. Embryonic stem cells (ESCs), standard model for pluripotency studies, have been recently flanked by induced pluripotent stem cells (iPSCs). iPSCs are obtained from somatic cells via epigenetic and transcriptional reprogramming, overcoming ESC-related ethical issues and enabling the possibility of donor-matching pluripotent cell lines. Since the European Court of Justice banned patents involving embryo disaggregation to generate human ESCs, iPSCs can now fuel the willingness of European companies to invest in treatments based on stem cells. Moreover, iPSCs share many unique features of ESCs, such as unlimited self-renewal potential and broad differentiation capability, even though iPSCs seem more susceptible to genomic instability and display epigenetic biases as compared to ESCs. Both ESCs and iPSCs have been intensely investigated for cardiomyocyte production and cardiac muscle regeneration, both in human and animal models. In vitro and in vivo studies are continuously expanding and refining this field via genetic manipulation and cell conditioning, trying to achieve standard and reproducible products, eligible for clinical and biopharmaceutical scopes. This review focuses on the recently growing body of patents, concerning technical advances in production, expansion and cardiac differentiation of ESCs and iPSCs.

  19. Recent advances in T-cell engineering for use in immunotherapy

    PubMed Central

    Sharma, Preeti; Kranz, David M.

    2016-01-01

    Adoptive T-cell therapies have shown exceptional promise in the treatment of cancer, especially B-cell malignancies. Two distinct strategies have been used to redirect the activity of ex vivo engineered T cells. In one case, the well-known ability of the T-cell receptor (TCR) to recognize a specific peptide bound to a major histocompatibility complex molecule has been exploited by introducing a TCR against a cancer-associated peptide/human leukocyte antigen complex. In the other strategy, synthetic constructs called chimeric antigen receptors (CARs) that contain antibody variable domains (single-chain fragments variable) and signaling domains have been introduced into T cells. Whereas many reviews have described these two approaches, this review focuses on a few recent advances of significant interest. The early success of CARs has been followed by questions about optimal configurations of these synthetic constructs, especially for efficacy against solid tumors. Among the many features that are important, the dimensions and stoichiometries of CAR/antigen complexes at the synapse have recently begun to be appreciated. In TCR-mediated approaches, recent evidence that mutated peptides (neoantigens) serve as targets for endogenous T-cell responses suggests that these neoantigens may also provide new opportunities for adoptive T-cell therapies with TCRs.

  20. Recent advances in the understanding of the Aspergillus fumigatus cell wall.

    PubMed

    Lee, Mark J; Sheppard, Donald C

    2016-03-01

    Over the past several decades, research on the synthesis and organization of the cell wall polysaccharides of Aspergillus fumigatus has expanded our knowledge of this important fungal structure. Besides protecting the fungus from environmental stresses and maintaining structural integrity of the organism, the cell wall is also the primary site for interaction with host tissues during infection. Cell wall polysaccharides are important ligands for the recognition of fungi by the innate immune system and they can mediate potent immunomodulatory effects. The synthesis of cell wall polysaccharides is a complicated process that requires coordinated regulation of many biosynthetic and metabolic pathways. Continuous synthesis and remodeling of the polysaccharides of the cell wall is essential for the survival of the fungus during development, reproduction, colonization and invasion. As these polysaccharides are absent from the human host, these biosynthetic pathways are attractive targets for antifungal development. In this review, we present recent advances in our understanding of Aspergillus fumigatus cell wall polysaccharides, including the emerging role of cell wall polysaccharides in the host-pathogen interaction.

  1. Recent advances in T-cell engineering for use in immunotherapy

    PubMed Central

    Sharma, Preeti; Kranz, David M.

    2016-01-01

    Adoptive T-cell therapies have shown exceptional promise in the treatment of cancer, especially B-cell malignancies. Two distinct strategies have been used to redirect the activity of ex vivo engineered T cells. In one case, the well-known ability of the T-cell receptor (TCR) to recognize a specific peptide bound to a major histocompatibility complex molecule has been exploited by introducing a TCR against a cancer-associated peptide/human leukocyte antigen complex. In the other strategy, synthetic constructs called chimeric antigen receptors (CARs) that contain antibody variable domains (single-chain fragments variable) and signaling domains have been introduced into T cells. Whereas many reviews have described these two approaches, this review focuses on a few recent advances of significant interest. The early success of CARs has been followed by questions about optimal configurations of these synthetic constructs, especially for efficacy against solid tumors. Among the many features that are important, the dimensions and stoichiometries of CAR/antigen complexes at the synapse have recently begun to be appreciated. In TCR-mediated approaches, recent evidence that mutated peptides (neoantigens) serve as targets for endogenous T-cell responses suggests that these neoantigens may also provide new opportunities for adoptive T-cell therapies with TCRs. PMID:27703664

  2. A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.; Bennett, William R.

    2010-01-01

    NASAs Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair Lunar Lander and the Extravehicular Activities (EVA) advanced Lunar surface spacesuit. These customers require safe, reliable batteries with extremely high specific energy as compared to state-of-the-art. The specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery-level at 0 degrees Celsius ( C) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation between 0 and 30 C and 200 cycles are targeted. Electrode materials that were considered include layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. Advanced cell chemistry options were evaluated with respect to multiple quantitative and qualitative attributes while considering their projected performance at the end of the available development timeframe. Following a rigorous ranking process, a chemistry that combines a lithiated nickel manganese cobalt oxide Li(LiNMC)O2 cathode with a silicon-based composite anode was selected as the technology that can potentially offer the best combination of safety, specific energy, energy density, and likelihood of success.

  3. Advanced basal cell carcinoma, the hedgehog pathway, and treatment options – role of smoothened inhibitors

    PubMed Central

    Fecher, Leslie A; Sharfman, William H

    2015-01-01

    Cutaneous basal cell carcinoma (BCC) is the most common human cancer and its incidence is rising worldwide. Ultraviolet radiation exposure, including tanning bed use, as well as host factors play a role in its development. The majority of cases are treated and cured with local therapies including surgery. Yet, the health care costs of diagnosis and treatment of BCCs in the US is substantial. In the United States, the cost of nonmelanoma skin cancer care in the Medicare population is estimated to be US$426 million per year. While rare, locally advanced BCCs that can no longer be controlled with surgery and/or radiation, and metastatic BCCs do occur and can be associated with significant morbidity and mortality. Vismodegib (GDC-0449), a smoothened inhibitor targeted at the hedgehog pathway, is the first US Food and Drug Association (FDA)-approved agent in the treatment of locally advanced, unresectable, and metastatic BCCs. This class of agents appears to be changing the survival rates in advanced BCC patients, but appropriate patient selection and monitoring are important. Multidisciplinary assessments are essential for the optimal care and management of these patients. For some patients with locally advanced BCC, treatment with a hedgehog inhibitor may eliminate the need for an excessively disfiguring or morbid surgery. PMID:26604681

  4. Vismodegib: A smoothened inhibitor for the treatment of advanced basal cell carcinoma.

    PubMed

    Aditya, Suruchi; Rattan, Aditya

    2013-10-01

    Incidence of basal cell carcinoma (BCC), the most common skin cancer in humans, is rising. Surgery is the mainstay of treatment but there is no standard of care for locally advanced or metastatic disease. Hedgehog signaling proteins are critical for cell growth and differentiation during embryogenesis; Hh pathway is silenced in adults. Dysregulated or aberrant Hh signaling has been implicated in the pathogenesis of BCC. This hyperactive pathway can be inhibited by use of smoothened inhibitors such as vismodegib. Food and drug administration approved this oral, once-daily medication in 2012 to treat adults with metastatic BCC or locally advanced, recurrent BCC after surgery and also for patients with locally advanced BCC who are not candidates for surgery or radiation treatment. Clinical studies have shown it to be highly efficacious and the most common adverse effects include, muscle spasms, alopecia and dysgeusia. Use of targeted biologic modifiers, exemplified by Hh directed therapeutics offer a new hope to patients with high-surgical morbidity or inoperable tumors.

  5. Fuel Cells for Portable Power: 1. Introduction to DMFCs; 2. Advanced Materials and Concepts for Portable Power Fuel Cells

    SciTech Connect

    Zelenay, Piotr

    2012-07-16

    Thanks to generally less stringent cost constraints, portable power fuel cells, the direct methanol fuel cell (DMFC) in particular, promise earlier market penetration than higher power polymer electrolyte fuel cells (PEFCs) for the automotive and stationary applications. However, a large-scale commercialization of DMFC-based power systems beyond niche applications already targeted by developers will depend on improvements to fuel cell performance and performance durability as well as on the reduction in cost, especially of the portable systems on the higher end of the power spectrum (100-250 W). In this part of the webinar, we will focus on the development of advanced materials (catalysts, membranes, electrode structures, and membrane electrode assemblies) and fuel cell operating concepts capable of fulfilling two key targets for portable power systems: the system cost of $5/W and overall fuel conversion efficiency of 2.0-2.5 kWh/L. Presented research will concentrate on the development of new methanol oxidation catalysts, hydrocarbon membranes with reduced methanol crossover, and improvements to component durability. Time permitted, we will also present a few highlights from the development of electrocatalysts for the oxidation of two alternative fuels for the direct-feed fuel cells: ethanol and dimethyl ether.

  6. Investigation of novel electrolyte systems for advanced metal/air batteries and fuel cells

    NASA Astrophysics Data System (ADS)

    Ye, Hui

    It is a worldwide challenge to develop advanced green power sources for modern portable devices, transportation and stationary power generation. Metal/air batteries and fuel cells clearly stand out in view of their high specific energy, high energy efficiency and environment-friendliness. Advanced metal/air batteries based on metal ion conductors and proton exchange membrane (PEM) fuel cells operated at elevated temperatures (>120°C) can circumvent the limitations of current technologies and bring considerable advantages. The key is to develop suitable electrolytes to enable these new technologies. In this thesis research, investigation of novel electrolytes systems for advanced metal/air batteries and PEM fuel cells is conducted. Novel polymer gel electrolyte systems, [metal salt/ionic liquid/polymer] and [metal salt/liquid polyether/polymer] are prepared. Such systems contain no volatile solvents, conduct metal ions (Li+ or Zn 2+) with high ionic conductivity, possess wide electrochemical stability windows, and exhibit wide operating temperature ranges. They promise to enable non-aqueous, all-solid-state, thin-film Li/air batteries and Zn/air batteries. They are advantageous for application in other battery systems as well, such as rechargeable lithium and lithium ion batteries. In the case of proton exchange membranes, polymer gel electrolyte systems [acid/ionic liquid/polymer] are prepared. Especially, H3PO4/PMIH2PO 4/PBI is demonstrated as prospective proton exchange membranes for PEM fuel cells operating at elevated temperatures. Comprehensive electrochemical characterization, thermal analysis (TGA and DSC) and spectroscopy analysis (NMR and FTIR) are carried out to investigate these novel electrolyte systems and their ion transport mechanisms. The design and synthesis of novel ionic liquids and electrolyte systems based on them for advantageous application in various electrochemical power sources are highlighted in this work.

  7. Advances in induced pluripotent stem cells, genomics, biomarkers, and antiplatelet therapy highlights of the year in JCTR 2013.

    PubMed

    Barbato, Emanuele; Lara-Pezzi, Enrique; Stolen, Craig; Taylor, Angela; Barton, Paul J; Bartunek, Jozef; Iaizzo, Paul; Judge, Daniel P; Kirshenbaum, Lorrie; Blaxall, Burns C; Terzic, Andre; Hall, Jennifer L

    2014-07-01

    The Journal provides the clinician and scientist with the latest advances in discovery research, emerging technologies, preclinical research design and testing, and clinical trials. We highlight advances in areas of induced pluripotent stem cells, genomics, biomarkers, multimodality imaging, and antiplatelet biology and therapy. The top publications are critically discussed and presented along with anatomical reviews and FDA insight to provide context.

  8. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Second Results Report and Appendices

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-10-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This is the second results report for the AT fuel cell bus since it was placed in service, and it focuses on the newest data analysis and lessons learned since the previous report. The appendices, referenced in the main report, provide the full background for the evaluation. They will be updated as new information is collected but will contain the original background material from the first report.

  9. NASA's First Year Progress with Fuel Cell Advanced Development in Support of the Exploration Vision

    NASA Technical Reports Server (NTRS)

    Hoberecht, Mark

    2007-01-01

    NASA Glenn Research Center (GRC), in collaboration with Johnson Space Center (JSC), the Jet Propulsion Laboratory (JPL), Kennedy Space Center (KSC), and industry partners, is leading a proton-exchange-membrane fuel cell (PEMFC) advanced development effort to support the vision for Exploration. This effort encompasses the fuel cell portion of the Energy Storage Project under the Exploration Technology Development Program, and is directed at multiple power levels for both primary and regenerative fuel cell systems. The major emphasis is the replacement of active mechanical ancillary components with passive components in order to reduce mass and parasitic power requirements, and to improve system reliability. A dual approach directed at both flow-through and non flow-through PEMFC system technologies is underway. A brief overview of the overall PEMFC project and its constituent tasks will be presented, along with in-depth technical accomplishments for the past year. Future potential technology development paths will also be discussed.

  10. From Uniplex to Multiplex Molecular Profiling in Advanced Non-Small Cell Lung Carcinoma.

    PubMed

    Ileana, Ecaterina E; Wistuba, Ignacio I; Izzo, Julie G

    2015-01-01

    Non-small cell lung carcinoma is a leading cause of cancer death worldwide. Understanding the molecular biology of survival and proliferation of cancer cells led to a new molecular classification of lung cancer and the development of targeted therapies with promising results. With the advances of image-guided biopsy techniques, tumor samples are becoming smaller, and the molecular testing techniques have to overcome the challenge of integrating the characterization of a panel of abnormalities including gene mutations, copy-number changes, and fusions in a reduced number of assays using only a small amount of genetic material. This article reviews the current knowledge about the most frequent actionable molecular abnormalities in non-small cell lung carcinoma, the new approaches of molecular analysis, and the implications of these findings in the context of clinical practice.

  11. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Third Results Reports

    SciTech Connect

    Eudy, L.; Chandler, K.

    2012-05-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. NREL has previously published two reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from July 2011 through January 2012.

  12. Recent advancements in structured-illumination microscopy toward live-cell imaging.

    PubMed

    Hirano, Yasuhiro; Matsuda, Atsushi; Hiraoka, Yasushi

    2015-08-01

    Fluorescence microscopy allows us to observe fluorescently labeled molecules in diverse biological processes and organelle structures within living cells. However, the diffraction limit restricts its spatial resolution to about half of its wavelength, limiting the capability of biological observation at the molecular level. Structured-illumination microscopy (SIM), a type of super-resolution microscopy, doubles the spatial resolution in all three dimensions by illuminating the sample with a patterned excitation light, followed by computer reconstruction. SIM uses a relatively low illumination power compared with other methods of super-resolution microscopy and is easily available for multicolor imaging. SIM has great potential for meeting the requirements of live-cell imaging. Recent developments in diverse types of SIM have achieved higher spatial (∼50 nm lateral) and temporal (∼100 Hz) resolutions. Here, we review recent advancements in SIM and discuss its application in noninvasive live-cell imaging. PMID:26133185

  13. Theory of Quantum Hall Nematics

    NASA Astrophysics Data System (ADS)

    Radzihovsky, Leo; Dorsey, Alan

    2002-03-01

    Transport measurements on two dimensional electron systems in moderate magnetic fields suggest the existence of a spontaneously orientationally-ordered, compressible liquid state. We develop and analyze [1] a microscopic theory of such a ``quantum Hall nematic'' (QHN) phase, predict the existence of a novel, highly anisotropic q^3 density-director mode, find that the T=0 long-range orientational order is unstable to weak disorder, and compute the tunneling into such a strongly correlated state. This microscopic approach is supported and complemented by a hydrodynamic model of the QHN, which, in the dissipationless limit, reproduces the modes of the microscopic model. This research was supported by NSF DMR-9978547, DMR-9625111, and the Sloan and Packard Foundations. [1] L. Radzihovsky and A. T. Dorsey, cond-mat/0110083

  14. The quantum Hall impedance standard

    NASA Astrophysics Data System (ADS)

    Schurr, J.; Kučera, J.; Pierz, K.; Kibble, B. P.

    2011-02-01

    Alternating current measurements of double-shielded quantum Hall devices have revealed a fascinating property of which only a quantum effect is capable: it can detect its own frequency dependence and convert it to a current dependence which can be used to eliminate both of them. According to an experimentally verified model, the residual frequency dependence is smaller than the measuring uncertainty of 1.3 × 10-9 kHz-1. In this way, a highly precise quantum standard of impedance can be established, without having to correct for any calculated frequency dependence and without the need for any artefact with a calculated frequency dependence. Nothing else like that is known to us and we hope that our results encourage other national metrology institutes to also apply it to impedance metrology and further explore its beautiful properties.

  15. The quantum Hall effect helicity

    SciTech Connect

    Shrivastava, Keshav N.

    2015-04-16

    The quantum Hall effect in semiconductor heterostructures is explained by two signs in the angular momentum j=l±s and g=(2j+1)/(2l+1) along with the Landau factor (n+1/2). These modifications in the existing theories explain all of the fractional charges. The helicity which is the sign of the product of the linear momentum with the spin p.s plays an important role for the understanding of the data at high magnetic fields. In particular it is found that particles with positive sign in the spin move in one direction and those with negative sign move in another direction which explains the up and down stream motion of the particles.

  16. Predicting Hall Thruster Operational Lifetime

    NASA Technical Reports Server (NTRS)

    Manzella, David; Yim, John; Boyd, Iain

    2004-01-01

    A simple analytic model predicted Hall thruster channel erosion based on thruster geometry, operating conditions, and magnetic field configuration. This model relied on a one-dimensional representation of the plasma with a fixed ionization fraction and variable ion energies based on the magnetic field distribution. Sputtering was modeled as the result of elastic scattering of ions by neutrals within the channel. Not all scattered ions and neutrals were assumed to reach the channel walls as a result of additional subsequent scattering events. Incorporating this phenomenon resulted in a greater predicted decrease in erosion rate with time than predicted based only on geometric effects. Results from this model were compared to SPT 100 experimental erosion data.

  17. Generalized Clustered Quantum Hall States

    NASA Astrophysics Data System (ADS)

    Simon, Steven H.; Cooper, Nigel R.; Rezayi, Ed

    2005-03-01

    The Read-Rezayi (parafermion) quantum Hall states[1] for bosons can be defined as states where the wavefunction does not vanish when g bosons come together to the same point, but does vanish as z^2 as a g+1st particle approaches that point. These states can equivalently be defined as the unique ground state of a point contact g+1 particle interaction Hamiltonian. Interestingly, the series of Read-Rezayi states appears to describe well the groundstates of rotating Bose condensates with point-contact two body interactions at a series of filling fractions [2]. If one attaches a Jastrow factor to such bose wavefunctions, one obtains fermion wavefunctions that may occur in electronic quantum Hall systems including the (g=2) Pfaffian [3] and the (g=3) ν=13/5 Read-Rezayi state [1]. In this work, we consider generalized cluster wavefunctions defined by the algebraic manner in which a wavefunction vanishes as g+1 particles coalesce. We find Hamiltonians that generate these wavefunctions as their exact ground state. Among this series of states is the previously studied Haffnian wavefunction[4] and a host of states not previously discussed. We catalogue and study the new states and discuss whether any of them might occur in actual physical systems. [1] N. Read and E. Rezayi, PRB59, 8084 (1999). [2] N. R. Cooper, N. K. Wilkin, and J. M. F. Gunn, PRL87, 120405 (2001) [3] G. Moore and N. Read, Nuc. Phys. B360, 362 (1991). [4] D. Green, PhD Thesis.

  18. Donor Natural Killer Cells After Donor Stem Cell Transplant in Treating Patients With Advanced Cancer

    ClinicalTrials.gov

    2013-02-18

    Brain and Central Nervous System Tumors; Chronic Myeloproliferative Disorders; Leukemia; Lymphoma; Lymphoproliferative Disorder; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Myelodysplastic/Myeloproliferative Neoplasms; Unspecified Adult Solid Tumor, Protocol Specific

  19. Advances in thin-film solar cells for lightweight space photovoltaic power

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Bailey, Sheila G.; Flood, Dennis J.

    1989-01-01

    The present stature and current research directions of photovoltaic arrays as primary power systems for space are reviewed. There have recently been great advances in the technology of thin-film solar cells for terrestrial applications. In a thin-film solar cell the thickness of the active element is only a few microns; transfer of this technology to space arrays could result in ultralow-weight solar arrays with potentially large gains in specific power. Recent advances in thin-film solar cells are reviewed, including polycrystalline copper-indium selenide (CuInSe2) and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon:hydrogen and alloys. The best experimental efficiency on thin-film solar cells to date is 12 percent AMO for CuIn Se2. This efficiency is likely to be increased in the next few years. The radiation tolerance of thin-film materials is far greater than that of single-crystal materials. CuIn Se2 shows no degradation when exposed to 1 MeV electrons. Experimental evidence also suggests that most of all of the radiation damage on thin-films can be removed by a low temperature anneal. The possibility of thin-film multibandgap cascade solar cells is discussed, including the tradeoffs between monolithic and mechanically stacked cells. The best current efficiency for a cascade is 12.5 percent AMO for an amorphous silicon on CuInSe2 multibandgap combination. Higher efficiencies are expected in the future. For several missions, including solar-electric propulsion, a manned Mars mission, and lunar exploration and manufacturing, thin-film photovolatic arrays may be a mission-enabling technology.

  20. Advances in pluripotent stem cell-derived endothelial cells: from biomaterials to organ regeneration.

    PubMed

    Lui, Kathy O

    2014-01-01

    Human embryonic stem cells (ESCs), by virtue of their capability to self-renew and differentiate into a variety of cell types, represent the first type of pluripotent stem cells (PSCs) to be used in clinical transplantation during recent phase-I trials; however, it is still unclear whether hESC-derived tissues can self-organize and form part of the vascularized, functional organ following transplantation. Recently, endothelial cells (ECs) or angiogenic factors such as VEGFA have been demonstrated to support development and regeneration of multiple organ systems, including the heart, pancreas, liver, lung and bone marrow. Therefore, co-transplantation of ECs derived from the same parental PSCs that differentiate into cell types of interest; or overexpression of the inductive angiogenic factors responsible for organ regeneration might be beneficial to support function of hPSC-derived tissues. In this special issue, we discuss how protein kinases (Ng and colleagues); DNA methylation and histone modification (Tsui and colleagues) regulate cellular pluripotency and cell-fate specification of PSCs. In addition, we discuss how ECs and angiogenic factors could contribute to repair and regeneration of organs such as the heart (Yuan and colleagues), the cardiovascular system (Tse and colleagues) and the pancreas (Lui). We also discuss the role of mesenchymal stem cells or paracrine factors secreted by them in tissue repair (Li and colleagues). Lastly, we discuss how to generate self-organized and vascularized tissues derived from PSCs in a 2- or 3-dimensional format by fusing tissue bioengineering approaches with stem cell technology (Chen).

  1. Salivary biomarkers for detection of oral squamous cell carcinoma – current state and recent advances

    PubMed Central

    Yakob, Maha; Fuentes, Laurel; Wang, Marilene B.; Abemayor, Elliot; Wong, David T.W.

    2014-01-01

    Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasm of the oral cavity. Detection of OSCC is currently based on thorough clinical oral examination combined with biopsy for histological analysis. Most cases of OSCC are not detected until the cancer has developed into advanced stages; thus, a reliable early stage diagnostic marker is needed. This literature review presents an overview of the status of current advances in salivary diagnostics for OSCC. Though many protein and mRNA salivary biomarkers have been identified that can detect OSCC with high sensitivity and specificity, the most discernable findings occur with the use of multiple markers. Studies that incorporate proteomic, transcriptomic, and potentially additional “omics”, including methylomics, need to be initiated to bring technology to clinical applications and allow the best use of saliva in diagnosing OSCC. PMID:24883261

  2. Analysis of advanced vapor source for cadmium telluride solar cell manufacturing

    NASA Astrophysics Data System (ADS)

    Khetani, Tejas Harshadkumar

    A thin film CdS/CdTe solar cell manufacturing line has been developed in the Materials Engineering Laboratory at Colorado State University. The original design incorporated infrared lamps for heating the vapor source. This system has been redesigned to improve the energy efficiency of the system, allow co-sublimation and allow longer run time before the sources have to be replenished. The advanced vapor source incorporates conduction heating with heating elements embedded in graphite. The advanced vapor source was modeled by computational fluid dynamics (CFD). From these models, the required maximum operating temperature of the element was determined to be 720 C for the processing of CdS/CdTe solar cells. Nichrome and Kanthal A1 were primarily selected for this application at temperature of 720 °C in vacuum with oxygen partial pressure. Research on oxidation effects and life due to oxidation as well as creep deformation was done, and Nichrome was found more suitable for this application. A study of the life of the Nichrome heating elements in this application was conducted and the estimate of life is approximately 1900 years for repeated on-off application. This is many orders of magnitude higher than the life of infrared heat lamps. Ceramic cement based on aluminum oxide (Resbond 920) is used for bonding the elements to the graphite. Thermodynamic calculations showed that this cement is inert to the heating element. An earlier design of the advanced source encountered failure of the element. The failed element was studies by scanning electron microscopy and the failure was attributed to loss of adhesion between the graphite and the ceramic element. The design has been modified and the advanced vapor source is currently in operation.

  3. An advanced application of protein microarrays: cell-based assays for functional genomics.

    PubMed

    Carbone, Roberta

    2009-01-01

    Microarrays have become common tools for approaching different experimental questions: DNA, protein and peptide arrays offer the power of multiplexing the assay and by means of miniaturization technology, the possibility to reduce cost and amount of samples and reagents. Recently, a novel technology for functional assays has been proposed. Sabatini and co-workers have shown a cell-based microarrays method (1) that relies on the deposition and immobilization of an array of cDNA plasmids on a slide where cells are subsequently plated; the cDNA is then internalized by "reverse transfection" and cells overexpress or downregulate in each single spot the genes of interest. This approach allows the screening of different phenotypes in living cells of many genes in parallel on a single slide. To overcome some relevant limitations of this approach, we have implemented the technology by means of viral immobilization (2) on a novel surface of cluster-assembled nanostructured TiO2 (3) previously functionalized with an array of a docking protein. In this work, we present the detailed development of the "reverse infection cell-microarray based technology" in U2OS cells on a novel coated slide that represents an advanced application of protein arrays.

  4. Advances in T Helper 17 Cell Biology: Pathogenic Role and Potential Therapy in Multiple Sclerosis

    PubMed Central

    Volpe, Elisabetta; Battistini, Luca; Borsellino, Giovanna

    2015-01-01

    The discovery of the T helper (Th) 17 lineage, involved in the protection against fungal and extracellular bacterial infections, has profoundly revolutionized our current understanding of T cell-mediated responses in autoimmune diseases, including multiple sclerosis (MS). Indeed, recent data demonstrate the pathogenic role of Th17 cells in autoimmune disorders. In particular, studies in MS and in its animal model (EAE, experimental autoimmune encephalomyelitis) have revealed a crucial role of Th17 cells in the pathogenesis of autoimmune demyelinating diseases in both mice and humans. Over the past years, several important aspects concerning Th17 cells have been elucidated, such as the factors which promote or inhibit their differentiation and the effector cytokines which mediate their responses. The identification of the features endowing Th17 cells with high pathogenicity in MS is of particular interest, and discoveries in Th17 cell biology and function could lead to the design of new strategies aimed at modulating the immune response in MS. Here, we will discuss recent advances in this field, with particular focus on the mechanisms conferring pathogenicity in MS and their potential modulation. PMID:26770017

  5. Recent advances towards development and commercialization of plant cell culture processes for synthesis of biomolecules

    PubMed Central

    Wilson, Sarah A.; Roberts, Susan C.

    2011-01-01

    (1) Summary Plant cell culture systems were initially explored for use in commercial synthesis of several high value secondary metabolites, allowing for sustainable production that was not limited by the low yields associated with natural harvest or the high cost associated with complex chemical synthesis. Although there have been some commercial successes, most notably paclitaxel production from Taxus sp., process limitations exist with regards to low product yields and inherent production variability. A variety of strategies are being developed to overcome these limitations including elicitation strategies, in situ product removal and metabolic engineering with single genes and transcription factors. Recently, the plant cell culture production platform has been extended to pharmaceutically active heterologous proteins. Plant systems are beneficial because they are able to produce complex proteins that are properly glycosylated, folded and assembled without the risk of contamination by toxins that are associated with mammalian or microbial production systems. Additionally, plant cell culture isolates transgenic material from the environment, allows for more controllable conditions over field grown crops and promotes secretion of proteins to the medium, reducing downstream purification costs. Despite these benefits, the increase in cost of heterologous protein synthesis in plant cell culture as opposed to field grown crops is significant and therefore processes must be optimized with regards to maximizing secretion and enhancing protein stability in the cell culture media. This review discusses recent advancements in plant cell culture processing technology, focusing on progress towards overcoming the problems associated with commercialization of these production systems and highlighting recent commercial successes. PMID:22059985

  6. Guard Cell Signal Transduction Network: Advances in Understanding Abscisic Acid, CO2, and Ca2+ Signaling

    PubMed Central

    Kim, Tae-Houn; Böhmer, Maik; Hu, Honghong; Nishimura, Noriyuki; Schroeder, Julian I.

    2011-01-01

    Stomatal pores are formed by pairs of specialized epidermal guard cells and serve as major gateways for both CO2 influx into plants from the atmosphere and transpirational water loss of plants. Because they regulate stomatal pore apertures via integration of both endogenous hormonal stimuli and environmental signals, guard cells have been highly developed as a model system to dissect the dynamics and mechanisms of plant-cell signaling. The stress hormone ABA and elevated levels of CO2 activate complex signaling pathways in guard cells that are mediated by kinases/phosphatases, secondary messengers, and ion channel regulation. Recent research in guard cells has led to a new hypothesis for how plants achieve specificity in intracellular calcium signaling: CO2 and ABA enhance (prime) the calcium sensitivity of downstream calcium-signaling mechanisms. Recent progress in identification of early stomatal signaling components are reviewed here, including ABA receptors and CO2-binding response proteins, as well as systems approaches that advance our understanding of guard cell-signaling mechanisms. PMID:20192751

  7. Advanced NaBH4/H2O2 Fuel Cell for Space Applications

    NASA Astrophysics Data System (ADS)

    Miley, George H.; Kim, Kyu-Jung; Luo, Nie; Shrestha, Prajakti Joshi

    2009-03-01

    Fuel cells have played an important role in NASA's space program starting with the Gemini space program. However, improved fuel cell performance will be needed to enable demanding future missions. An advanced fuel cell (FC) using liquid fuel and oxidizer is being developed by U of IL/NPL team to provide air independence and to achieve higher power densities than normal H2/O2 fuel cells (Lou et al., 2008; Miley, 2007). Hydrogen peroxide (H2O2) is used in this FC directly at the cathode (Lou and Miley, 2004). Either of two types of reactant, namely a gas-phase hydrogen or an aqueous NaBH4 solution, is utilized as fuel at the anode. Experiments with both 10-W single cells and 500-W stacks demonstrate that the direct utilization of H2O2 and NaBH4 at the electrodes result in >30% higher voltage output compared to the ordinary H2/O2 FC (Miley, 2007). Further, the use of this combination of all liquid fuels provides—from an operational point of view—significant advantages (ease of storage, reduced pumping requirements, simplified heat removal). This design is inherently compact compared to other fuel cells that use gas phase reactants. This results in a high overall system (including fuel tanks, pumps and piping, waste heat radiator) power density. Further, work is in progress on a regenerative version which uses an electrical input, e.g. from power lines or a solar panel to regenerate reactants.

  8. Operation of graphene quantum Hall resistance standard in a cryogen-free table-top system

    NASA Astrophysics Data System (ADS)

    Janssen, T. J. B. M.; Rozhko, S.; Antonov, I.; Tzalenchuk, A.; Williams, J. M.; Melhem, Z.; He, H.; Lara-Avila, S.; Kubatkin, S.; Yakimova, R.

    2015-09-01

    We demonstrate quantum Hall resistance measurements with metrological accuracy in a small cryogen-free system operating at a temperature of around 3.8 K and magnetic fields below 5 T. Operating this system requires little experimental knowledge or laboratory infrastructure, thereby greatly advancing the proliferation of primary quantum standards for precision electrical metrology. This significant advance in technology has come about as a result of the unique properties of epitaxial graphene on SiC.

  9. Hall magnetoresistivity response under microwave excitation revisited

    SciTech Connect

    Inarrea, Jesus

    2007-04-23

    The authors theoretically analyzed the microwave-induced modification of the Hall magnetoresistivity in high mobility two-dimensional electron systems. These systems present diagonal magnetoresistivity oscillations and zero-resistance states when subjected to microwave radiation. The most surprising modification of the Hall magnetoresistivity is a periodic reduction which correlates with a periodic increase in the diagonal resistivity. The authors present a model that explains the experimental results considering that radiation affects directly only the diagonal resistivity and that the observed Hall resistivity changes come from the tensor relationship between them.

  10. Piezo Voltage Controlled Planar Hall Effect Devices

    NASA Astrophysics Data System (ADS)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  11. Chiral thermoelectrics with quantum Hall edge states.

    PubMed

    Sánchez, Rafael; Sothmann, Björn; Jordan, Andrew N

    2015-04-10

    The thermoelectric properties of a three-terminal quantum Hall conductor are investigated. We identify a contribution to the thermoelectric response that relies on the chirality of the carrier motion rather than on spatial asymmetries. The Onsager matrix becomes maximally asymmetric with configurations where either the Seebeck or the Peltier coefficients are zero while the other one remains finite. Reversing the magnetic field direction exchanges these effects, which originate from the chiral nature of the quantum Hall edge states. The possibility to generate spin-polarized currents in quantum spin Hall samples is discussed. PMID:25910147

  12. Chiral Thermoelectrics with Quantum Hall Edge States

    NASA Astrophysics Data System (ADS)

    Sánchez, Rafael; Sothmann, Björn; Jordan, Andrew N.

    2015-04-01

    The thermoelectric properties of a three-terminal quantum Hall conductor are investigated. We identify a contribution to the thermoelectric response that relies on the chirality of the carrier motion rather than on spatial asymmetries. The Onsager matrix becomes maximally asymmetric with configurations where either the Seebeck or the Peltier coefficients are zero while the other one remains finite. Reversing the magnetic field direction exchanges these effects, which originate from the chiral nature of the quantum Hall edge states. The possibility to generate spin-polarized currents in quantum spin Hall samples is discussed.

  13. Direct Drive for Low Power Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Dankanich, John W.

    2005-01-01

    Due to recent studies, NASA has initiated the development of a low power Hall thruster for discovery class missions. The potential advantages of a low power Hall thruster is primarily due to its high efficiency operation at low power and its lower complexity compared to ion engines. Direct drive is another method of reducing the complexity of a Hall thruster system while improving its efficiency. The technical challenges associated with this technology are reported. Additionally, the benefits of this technology are discussed based on parametric studies and mission analysis.

  14. Joule heating in spin Hall geometry

    NASA Astrophysics Data System (ADS)

    Taniguchi, Tomohiro

    2016-07-01

    The theoretical formula for the entropy production rate in the presence of spin current is derived using the spin-dependent transport equation and thermodynamics. This theory is applicable regardless of the source of the spin current, for example, an electric field, a temperature gradient, or the Hall effect. It reproduces the result in a previous work on the dissipation formula when the relaxation time approximation is applied to the spin relaxation rate. By using the developed theory, it is found that the dissipation in the spin Hall geometry has a contribution proportional to the square of the spin Hall angle.

  15. Piezo Voltage Controlled Planar Hall Effect Devices.

    PubMed

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  16. Frequently rearranged in advanced T-cell lymphomas-1 demonstrates oncogenic properties in prostate cancer

    PubMed Central

    Zhang, Wei; Xiong, Hua; Zou, Yanmei; Xu, Sanpeng; Quan, Lanping; Yuan, Xianglin; Xu, Ningzhi; Wang, Yihua

    2016-01-01

    Prostate cancer is the fifth most common cause of cancer-associated mortality for males worldwide. Although dysregulation of the β-catenin/T-cell factor (TCF) pathway has been previously reported in prostate cancer, the mechanisms underlying this process remain unknown. Frequently rearranged in advanced T-cell lymphomas-1 (FRAT1) functions as a positive regulator of the β-catenin/TCF signaling pathway. However, to the best of our knowledge, the molecular association between FRAT1 and the β-catenin/TCF pathway in prostate cancer has not been investigated. In the present study, FRAT1 expression was analyzed in normal prostate tissues and prostate adenocarcinoma samples using publicly available databases, a commercial tissue microarray and immunohistochemistry techniques. In addition, FRAT1 expression levels were altered by overexpression or RNA interference-mediated depletion in prostate cancer cells. The effects of FRAT1 expression on tumor growth were determined using cell growth curves in vitro and xenografts in nude mice in vivo. The effects of FRAT1 on β-catenin/TCF activity were measured using the TOPFLASH reporter assay. FRAT1 was expressed exclusively in the nuclei of normal prostate basal cells, and nuclear FRAT1 was detected in 68% (40/59) of prostate adenocarcinoma samples. In addition, FRAT1 activated the TCF luciferase reporter gene promoter in prostate cancer cells, and was observed to promote the growth of prostate cancer cells in vitro. Furthermore, FRAT1 expression was sufficient to transform NIH3T3 mouse embryonic fibroblast cells and lead to tumor formation in vivo. These results suggest that FRAT1 demonstrates oncogenic properties in prostate cancer, potentially by suppressing the inhibitory effect of nuclear glycogen synthase 3β against β-catenin/TCF activity, thus activating the Wnt/β-catenin signaling pathway and promoting cell growth. PMID:27599661

  17. Frequently rearranged in advanced T‑cell lymphomas‑1 demonstrates oncogenic properties in prostate cancer.

    PubMed

    Zhang, Wei; Xiong, Hua; Zou, Yanmei; Xu, Sanpeng; Quan, Lanping; Yuan, Xianglin; Xu, Ningzhi; Wang, Yihua

    2016-10-01

    Prostate cancer is the fifth most common cause of cancer‑associated mortality for males worldwide. Although dysregulation of the β‑catenin/T‑cell factor (TCF) pathway has been previously reported in prostate cancer, the mechanisms underlying this process remain unknown. Frequently rearranged in advanced T‑cell lymphomas‑1 (FRAT1) functions as a positive regulator of the β‑catenin/TCF signaling pathway. However, to the best of our knowledge, the molecular association between FRAT1 and the β‑catenin/TCF pathway in prostate cancer has not been investigated. In the present study, FRAT1 expression was analyzed in normal prostate tissues and prostate adenocarcinoma samples using publicly available databases, a commercial tissue microarray and immunohistochemistry techniques. In addition, FRAT1 expression levels were altered by overexpression or RNA interference‑mediated depletion in prostate cancer cells. The effects of FRAT1 expression on tumor growth were determined using cell growth curves in vitro and xenografts in nude mice in vivo. The effects of FRAT1 on β‑catenin/TCF activity were measured using the TOPFLASH reporter assay. FRAT1 was expressed exclusively in the nuclei of normal prostate basal cells, and nuclear FRAT1 was detected in 68% (40/59) of prostate adenocarcinoma samples. In addition, FRAT1 activated the TCF luciferase reporter gene promoter in prostate cancer cells, and was observed to promote the growth of prostate cancer cells in vitro. Furthermore, FRAT1 expression was sufficient to transform NIH3T3 mouse embryonic fibroblast cells and lead to tumor formation in vivo. These results suggest that FRAT1 demonstrates oncogenic properties in prostate cancer, potentially by suppressing the inhibitory effect of nuclear glycogen synthase 3β against β‑catenin/TCF activity, thus activating the Wnt/β‑catenin signaling pathway and promoting cell growth. PMID:27599661

  18. Cell and Gene Therapy for the Beta-Thalassemias: Advances and Prospects.

    PubMed

    Mansilla-Soto, Jorge; Riviere, Isabelle; Boulad, Farid; Sadelain, Michel

    2016-04-01

    The beta-thalassemias are inherited anemias caused by mutations that severely reduce or abolish expression of the beta-globin gene. Like sickle cell disease, a related beta-globin gene disorder, they are ideal candidates for performing a genetic correction in patient hematopoietic stem cells (HSCs). The most advanced approach utilizes complex lentiviral vectors encoding the human β-globin gene, as first reported by May et al. in 2000. Considerable progress toward the clinical implementation of this approach has been made in the past five years, based on effective CD34+ cell mobilization and improved lentiviral vector manufacturing. Four trials have been initiated in the United States and Europe. Of 16 evaluable subjects, 6 have achieved transfusion independence. One of them developed a durable clonal expansion, which regressed after several years without transformation. Although globin lentiviral vectors have so far proven to be safe, this occurrence suggests that powerful insulators with robust enhancer-blocking activity will further enhance this approach. The combined discovery of Bcl11a-mediated γ-globin gene silencing and advances in gene editing are the foundations for another gene therapy approach, which aims to reactivate fetal hemoglobin (HbF) production. Its clinical translation will hinge on the safety and efficiency of gene targeting in true HSCs and the induction of sufficient levels of HbF to achieve transfusion independence. Altogether, the progress achieved over the past 15 years bodes well for finding a genetic cure for severe globin disorders in the next decade.

  19. Progress in Materials and Component Development for Advanced Lithium-ion Cells for NASA's Exploration Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha, M.; Reid, Concha M.

    2011-01-01

    Vehicles and stand-alone power systems that enable the next generation of human missions to the Moon will require energy storage systems that are safer, lighter, and more compact than current state-of-the- art (SOA) aerospace quality lithium-ion (Li-ion) batteries. NASA is developing advanced Li-ion cells to enable or enhance the power systems for the Altair Lunar Lander, Extravehicular Activities spacesuit, and rovers and portable utility pallets for Lunar Surface Systems. Advanced, high-performing materials are required to provide component-level performance that can offer the required gains at the integrated cell level. Although there is still a significant amount of work yet to be done, the present state of development activities has resulted in the synthesis of promising materials that approach the ultimate performance goals. This report on interim progress of the development efforts will elaborate on the challenges of the development activities, proposed strategies to overcome technical issues, and present performance of materials and cell components.

  20. Third generation tyrosine kinase inhibitors and their development in advanced renal cell carcinoma.

    PubMed

    Bukowski, Ronald M

    2012-01-01

    Angiogenesis in general and the vascular endothelial growth factor (VEGF) signaling axis in particular is a validated target in renal cell carcinoma (RCC). Clear-cell carcinoma of the kidney is now recognized as a malignancy that is sensitive to inhibitors of the VEGF pathway. Treatment options for patients with metastatic renal cell carcinoma have evolved in dramatic fashion over the past 6 years, and a new paradigm has developed. The cytokines interferon-α and interleukin-2 were previously utilized for therapy, but since December 2005, six new agents have been approved in the United States for the treatment of advanced RCC. Two are tyrosine kinase inhibitors (TKI's) including sunitinib and recently pazopanib, and the multikinase inhibitor sorafenib. The current review examines the evolving data with the next generation of TKI's, axitinib and tivozanib being developed for the treatment of advanced RCC. These agents were synthesized to provide increased target specificity and enhanced target inhibition. The preclinical and clinical data are examined, an overview of the development of these TKI's is provided, and discussion plus speculation concerning their potential roles as RCC therapy is provided.

  1. Recent advances in renal cell carcinoma from a pathological point of view.

    PubMed

    Mikami, Shuji; Oya, Mototsugu; Mizuno, Ryuichi; Kosaka, Takeo; Ishida, Masaru; Kuroda, Naoto; Nagashima, Yoji; Katsube, Ken-Ichi; Okada, Yasunori

    2016-09-01

    The purpose of this article is to review the recent advances in renal cell carcinoma (RCC) from a pathological point of view. Because the genetic features and morphological characteristics have become major criteria for the classification of RCC, special techniques, such as immunohistochemistry, are essential to the differential diagnosis of renal tumors. Metastasis is frequently observed among the RCC patients with curative nephrectomy, and extracellular matrix-degrading enzymes, such as matrix metalloproteinases (MMP) and heparanase, play a key role in invasion and metastasis of RCC. Snail and Slug, transcription factors of epithelial-mesenchymal transition (EMT), accelerate cancer cell invasion through downregulation of E-cadherin and up-regulation of MMP. Therapies targeted at the vascular endothelial growth factor pathway have become the standard treatment of metastatic RCC. Although they lead to tumor shrinkage mainly by inhibiting angiogenesis, they have typically been associated with drug resistance. The mechanism of the resistance remains largely unknown, but complex events including re-activation of angiogenesis, EMT and cancer stem cells, and immune escape are implicated in the refractory response to the therapy. Recent advances of the research on RCC have caused the changes of classification and therapy, and pathologists should take overall view of these as integrated pathology.

  2. Some aspects of allogeneic stem cell transplantation in patients with myelodysplastic syndrome: advances and controversy

    PubMed Central

    Blau, Olga; Blau, Igor Wolfgang

    2014-01-01

    Myelodysplastic syndrome (MDS) is a heterogeneous group of myeloid disorders. MDS remains a disease of elderly patients; moreover, the incidence of high risk MDS is proportionally greater in elderly patients, with increased frequency of secondary acute myeloid leukemia, as well as adverse cytogenetic abnormalities. Allogeneic stem cell transplantation is a therapeutic approach with known curative potential for patients with MDS that allows the achievement of long-term disease control. Numerous controversies still exist regarding transplantation in MDS: timing of transplantation, disease status at transplantation and comorbidity, conditioning intensity, pretransplant therapy, and stem cell source. Various transplant modalities of different intensities and alternative donor sources are now in use. Current advances in transplant technology are allowing the consideration of older patients. This should result in a greater number of older patients benefiting from this potentially curative treatment modality. Despite advances in transplantation technology, there is still considerable morbidity and mortality associated with this approach. Nevertheless, with the introduction of reduced-intensity conditioning and thereby reduced early mortality, transplant numbers in MDS patients have significantly increased. Moreover, recent new developments with innovative drugs, including hypomethylating agents, have extended the therapeutic alternatives for MDS patients. Hypomethylating agents allow the delay of allogeneic stem cell transplantation by serving as an effective and well-tolerated means to reduce disease burden. PMID:25506229

  3. Assessment of High-Voltage Photovoltaic Technologies for the Design of a Direct Drive Hall Effect Thruster Solar Array

    NASA Technical Reports Server (NTRS)

    Mikellides, I. G.; Jongeward, G. A.; Schneider, T.; Carruth, M. R.; Peterson, T.; Kerslake, T. W.; Snyder, D.; Ferguson, D.; Hoskins, A.

    2004-01-01

    A three-year program to develop a Direct Drive Hall-Effect Thruster system (D2HET) begun in 2001 as part of the NASA Advanced Cross-Enterprise Technology Development initiative. The system, which is expected to reduce significantly the power processing, complexity, weight, and cost over conventional low-voltage systems, will employ solar arrays that operate at voltages higher than (or equal to) 300 V. The lessons learned from the development of the technology also promise to become a stepping-stone for the production of the next generation of power systems employing high voltage solar arrays. This paper summarizes the results from experiments conducted mainly at the NASA Marshal Space Flight Center with two main solar array technologies. The experiments focused on electron collection and arcing studies, when the solar cells operated at high voltages. The tests utilized small coupons representative of each solar array technology. A hollow cathode was used to emulate parts of the induced environment on the solar arrays, mostly the low-energy charge-exchange plasma (1012-1013 m-3 and 0.5-1 eV). Results and conclusions from modeling of electron collection are also summarized. The observations from the total effort are used to propose a preliminary, new solar array design for 2 kW and 30-40 kW class, deep space missions that may employ a single or a cluster of Hall- Effect thrusters.

  4. A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha; Bennett, William

    2009-01-01

    NASA's Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair lunar lander and the Extravehicular Activities (EVA) advanced lunar surface spacesuit. These customers require safe, reliable energy storage systems with extremely high specific energy as compared to today's state-of-the-art batteries. Based on customer requirements, the specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery level at 0 degrees Celsius (degrees Celcius) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation over 0 to 30 degrees C, and 200 cycles are targeted. The team, consisting of members from NASA Glenn Research Center, Johnson Space Center, and Jet Propulsion laboratory, surveyed the literature, compiled information on recent materials developments, and consulted with other battery experts in the community to identify advanced battery materials that might be capable of achieving the desired results with further development. A variety of electrode materials were considered, including layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. lithium-sulfur systems were also considered. Hypothetical cell constructs that combined compatible anode and cathode materials with suitable electrolytes, separators, current collectors, headers, and cell enclosures were modeled. While some of these advanced materials are projected to obtain the desired electrical performance, there are risks that also factored into the decision making process. The risks include uncertainties due to issues such as safety of a system containing some of these materials, ease of scaling-up of large batches of raw materials, adaptability of the materials to processing using established

  5. Performance Characterization of the Air Force Transformational Satellite 12 kW Hall Thruster

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Haag, Thomas W.; Smith, Timothy; Herman, Daniel; Huang, Wensheng; Shastry, Rohit; Peterson, Peter; Mathers, Alex

    2013-01-01

    The STMD GCD ISP project is tasked with developing, maturing, and testing enabling human exploration propulsion requirements and potential designs for advanced high-energy, in-space propulsion systems to support deep-space human exploration and reduce travel time between Earth's orbit and future destinations for human activity. High-power Hall propulsion systems have been identified as enabling technologies and have been the focus of the activities at NASA Glenn-In-house effort to evaluate performance and interrogate operation of NASA designed and manufactured Hall thrusters. Evaluate existing high TRL EP devices that may be suitable for implementation in SEP TDM.

  6. Topological insulators in silicene: Quantum hall, quantum spin hall and quantum anomalous hall effects

    SciTech Connect

    Ezawa, Motohiko

    2013-12-04

    Silicene is a monolayer of silicon atoms forming a two-dimensional honeycomb lattice, which shares almost every remarkable property with graphene. The low energy dynamics is described by Dirac electrons, but they are massive due to relatively large spin-orbit interactions. I will explain the following properties of silicene: 1) The band structure is controllable by applying an electric field. 2) Silicene undergoes a phase transition from a topological insulator to a band insulator by applying external electric field. 3) The topological phase transition can be detected experimentally by way of diamagnetism. 4) There is a novel valley-spin selection rules revealed by way of photon absorption. 5) Silicene yields a remarkably many phases such as quantum anomalous Hall phase and valley polarized metal when the exchange field is additionally introduced. 6) A silicon nanotubes can be used to convey spin currents under an electric field.

  7. Advanced chemical hydride-based hydrogen generation/storage system for fuel cell vehicles

    SciTech Connect

    Breault, R.W.; Rolfe, J.

    1998-08-01

    Because of the inherent advantages of high efficiency, environmental acceptability, and high modularity, fuel cells are potentially attractive power supplies. Worldwide concerns over clean environments have revitalized research efforts on developing fuel cell vehicles (FCV). As a result of intensive research efforts, most of the subsystem technology for FCV`s are currently well established. These include: high power density PEM fuel cells, control systems, thermal management technology, and secondary power sources for hybrid operation. For mobile applications, however, supply of hydrogen or fuel for fuel cell operation poses a significant logistic problem. To supply high purity hydrogen for FCV operation, Thermo Power`s Advanced Technology Group is developing an advanced hydrogen storage technology. In this approach, a metal hydride/organic slurry is used as the hydrogen carrier and storage media. At the point of use, high purity hydrogen will be produced by reacting the metal hydride/organic slurry with water. In addition, Thermo Power has conceived the paths for recovery and regeneration of the spent hydride (practically metal hydroxide). The fluid-like nature of the spent hydride/organic slurry will provide a unique opportunity for pumping, transporting, and storing these materials. The final product of the program will be a user-friendly and relatively high energy storage density hydrogen supply system for fuel cell operation. In addition, the spent hydride can relatively easily be collected at the pumping station and regenerated utilizing renewable sources, such as biomass, natural, or coal, at the central processing plants. Therefore, the entire process will be economically favorable and environmentally friendly.

  8. PD-1 Blockade with Pembrolizumab in Advanced Merkel-Cell Carcinoma

    PubMed Central

    Nghiem, Paul T.; Bhatia, Shailender; Lipson, Evan J.; Kudchadkar, Ragini R.; Miller, Natalie J.; Annamalai, Lakshmanan; Berry, Sneha; Chartash, Elliot K.; Daud, Adil; Fling, Steven P.; Friedlander, Philip A.; Kluger, Harriet M.; Kohrt, Holbrook E.; Lundgren, Lisa; Margolin, Kim; Mitchell, Alan; Olencki, Thomas; Pardoll, Drew M.; Reddy, Sunil A.; Shantha, Erica M.; Sharfman, William H.; Sharon, Elad; Shemanski, Lynn R.; Shinohara, Michi M.; Sunshine, Joel C.; Taube, Janis M.; Thompson, John A.; Townson, Steven M.; Yearley, Jennifer H.; Topalian, Suzanne L.; Cheever, Martin A.

    2016-01-01

    BACKGROUND Merkel-cell carcinoma is an aggressive skin cancer that is linked to exposure to ultraviolet light and the Merkel-cell polyomavirus (MCPyV). Advanced Merkel-cell carcinoma often responds to chemotherapy, but responses are transient. Blocking the programmed death 1 (PD-1) immune inhibitory pathway is of interest, because these tumors often express PD-L1, and MCPyV-specific T cells express PD-1. METHODS In this multicenter, phase 2, noncontrolled study, we assigned adults with advanced Merkel-cell carcinoma who had received no previous systemic therapy to receive pembrolizumab (anti–PD-1) at a dose of 2 mg per kilogram of body weight every 3 weeks. The primary end point was the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1. Efficacy was correlated with tumor viral status, as assessed by serologic and immunohistochemical testing. RESULTS A total of 26 patients received at least one dose of pembrolizumab. The objective response rate among the 25 patients with at least one evaluation during treatment was 56% (95% confidence interval [CI], 35 to 76); 4 patients had a complete response, and 10 had a partial response. With a median follow-up of 33 weeks (range, 7 to 53), relapses occurred in 2 of the 14 patients who had had a response (14%). The response duration ranged from at least 2.2 months to at least 9.7 months. The rate of progression-free survival at 6 months was 67% (95% CI, 49 to 86). A total of 17 of the 26 patients (65%) had virus-positive tumors. The response rate was 62% among patients with MCPyV-positive tumors (10 of 16 patients) and 44% among those with virus-negative tumors (4 of 9 patients). Drug-related grade 3 or 4 adverse events occurred in 15% of the patients. CONCLUSIONS In this study, first-line therapy with pembrolizumab in patients with advanced Merkel-cell carcinoma was associated with an objective response rate of 56%. Responses were observed in patients with virus-positive tumors

  9. Advances and issues in mantle cell lymphoma research: report of the 2014 Mantle Cell Lymphoma Consortium Workshop.

    PubMed

    Kahl, Brad S; Gordon, Leo I; Dreyling, Martin; Gascoyne, Randy D; Sotomayor, Eduardo M

    2015-01-01

    Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma characterized by the t(11;14) chromosomal translocation and cyclin D1 over-expression. A biologically and clinically heterogeneous lymphoma, MCL, remains clinically challenging, with no proven curative therapy and no established standard of care. However, there have been considerable advances in the last several years in the treatment and understanding of MCL with the FDA approval of lenalidomide and ibrutinib, the development of other potentially active novel agents and the identification of recurrent mutations through new genomic sequencing approaches that may contribute to the biology of MCL and to therapeutic resistance. At the Lymphoma Research Foundation's 11th MCL Workshop, researchers gathered to discuss recent studies and current issues related to the biology of MCL, novel therapeutic targets and new treatment strategies. The presentations are summarized in this manuscript, which is intended to highlight areas of active investigation and identify topics for future research.

  10. Topologically induced fractional Hall steps in the integer quantum Hall regime of MoS 2

    NASA Astrophysics Data System (ADS)

    Firoz Islam, SK; Benjamin, Colin

    2016-09-01

    The quantum magnetotransport properties of a monolayer of molybdenum disulfide are derived using linear response theory. In particular, the effect of topological terms on longitudinal and Hall conductivity is analyzed. The Hall conductivity exhibits fractional steps in the integer quantum Hall regime. Further complete spin and valley polarization of the longitudinal conductivitity is seen in presence of these topological terms. Finally, the Shubnikov-de Hass oscillations are suppressed or enhanced contingent on the sign of these topological terms.

  11. Topologically induced fractional Hall steps in the integer quantum Hall regime of MoS 2.

    PubMed

    Islam, S K Firoz; Benjamin, Colin

    2016-09-23

    The quantum magnetotransport properties of a monolayer of molybdenum disulfide are derived using linear response theory. In particular, the effect of topological terms on longitudinal and Hall conductivity is analyzed. The Hall conductivity exhibits fractional steps in the integer quantum Hall regime. Further complete spin and valley polarization of the longitudinal conductivitity is seen in presence of these topological terms. Finally, the Shubnikov-de Hass oscillations are suppressed or enhanced contingent on the sign of these topological terms.

  12. Topologically induced fractional Hall steps in the integer quantum Hall regime of MoS 2.

    PubMed

    Islam, S K Firoz; Benjamin, Colin

    2016-09-23

    The quantum magnetotransport properties of a monolayer of molybdenum disulfide are derived using linear response theory. In particular, the effect of topological terms on longitudinal and Hall conductivity is analyzed. The Hall conductivity exhibits fractional steps in the integer quantum Hall regime. Further complete spin and valley polarization of the longitudinal conductivitity is seen in presence of these topological terms. Finally, the Shubnikov-de Hass oscillations are suppressed or enhanced contingent on the sign of these topological terms. PMID:27533362

  13. Development of an advanced bond coat for solid oxide fuel cell interconnector applications

    NASA Astrophysics Data System (ADS)

    Yeh, An-Chou; Chen, Yu-Ming; Liu, Chien-Kuo; Shong, Wei-Ja

    2015-11-01

    An advanced bond coat has been developed for solid oxide fuel cell interconnector applications; a low thermal expansion superalloy has been selected as the substrate, and the newly developed bond coat is applied between the substrate and the LSM top coat. The bond coat composition is designed to be near thermodynamic equilibrium with the substrate to minimize interdiffusion with the substrate while providing oxidation protection for the substrate. The bond coat exhibits good oxidation resistance, a low area specific resistance, and a low thermal expansion coefficient at 800 °C; experimental results indicate that interdiffusion between the bond coat and the substrate can be hindered.

  14. Cell therapy, advanced materials, and new approaches to acute kidney injury.

    PubMed

    Yevzlin, Alexander S; Humes, H David

    2009-12-01

    Acute renal failure (ARF) is a common clinical syndrome characterized by an abrupt deterioration in kidney function, resulting in abnormalities in volume-regulatory, metabolic-regulatory, excretory, and endocrine functions. Despite decades of improvements in the provision of intensive care, and specifically in the provision of renal replacement therapy, the morbidity and mortality associated with acute kidney injury (AKI) remain extremely high. This article highlights novel cell therapies, advanced materials, and approaches to AKI with the aim of illuminating a potential path for future basic, translational, and clinical research using these novel modalities.

  15. Titanocenes: Cytotoxic and Anti-angiogenic Chemotherapy Against Advanced Renal-Cell Cancer

    NASA Astrophysics Data System (ADS)

    Hogan, Megan; Tacke, Matthias

    6-Substituted fulvenes are interesting and easily accessible starting materials for the synthesis of novel-substituted titanocenes via reductive dimerisation, carbolithiation or hydridolithiation reactions, which are followed by a transmetallation reaction with titanium tetrachloride in the latter two cases. Depending on the substitution pattern, these titanocenes prove to be bioorganometallic anticancer drugs, which have significant potential against advanced or metastatic renal-cell cancer. Patients bearing these stages of kidney cancer have a poor prognosis so far and therefore real progress in the area of metal-based anticancer drugs may come from this simple and effective synthetic approach.

  16. Immunological Treatment Options for Locoregionally Advanced Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Mirandola, Leonardo; Bernardini, Giovanni; Cunha, Nicholas D’; Tijani, Lukman; Nguyen, Diane; Cordero, Joehassin; Jenkins, Marjorie R.; Cobos, Everardo; Kast, W. Martin; Chiriva-Internati, Maurizio

    2014-01-01

    Patients with squamous cell carcinoma of the head and neck (HNSCC) are usually treated by a multimodal approach with surgery and/or radiochemotherapy as the mainstay of local–regional treatment in cases with advanced disease. Both chemotherapy and radiation therapy have the disadvantage of causing severe side effects, while the clinical outcome of patients diagnosed with HNSCC has remained essentially unchanged over the last decade. The potential of immunotherapy is still largely unexplored. Here the authors review the current status of the art and discuss the future challenges in HNSCC treatment and prevention. PMID:22251006

  17. The effect of the low Earth orbit environment on space solar cells: Results of the Advanced Photovoltaic Experiment (S0014)

    NASA Technical Reports Server (NTRS)

    Brinker, David J.; Hickey, John R.; Scheiman, David A.

    1993-01-01

    The results of post-flight performance testing of the solar cells flown on the Advanced Photovoltaic Experiment are reported. Comparison of post-flight current-voltage characteristics with similar pre-flight data revealed little or no change in solar cell conversion efficiency, confirming the reliability and endurance of space photovoltaic cells. This finding is in agreement with the lack of significant physical changes in the solar cells despite nearly six years in the low Earth orbit environment.

  18. Advanced feeder-free generation of induced pluripotent stem cells directly from blood cells.

    PubMed

    Trokovic, Ras; Weltner, Jere; Nishimura, Ken; Ohtaka, Manami; Nakanishi, Mahito; Salomaa, Veikko; Jalanko, Anu; Otonkoski, Timo; Kyttälä, Aija

    2014-12-01

    Generation of validated human induced pluripotent stem cells (iPSCs) for biobanking is essential for exploring the full potential of iPSCs in disease modeling and drug discovery. Peripheral blood mononuclear cells (PBMCs) are attractive targets for reprogramming, because blood is collected by a routine clinical procedure and is a commonly stored material in biobanks. Generation of iPSCs from blood cells has previously been reported using integrative retroviruses, episomal Sendai viruses, and DNA plasmids. However, most of the published protocols require expansion and/or activation of a specific cell population from PBMCs. We have recently collected a PBMC cohort from the Finnish population containing more than 2,000 subjects. Here we report efficient generation of iPSCs directly from PBMCs in feeder-free conditions in approximately 2 weeks. The produced iPSC clones are pluripotent and transgene-free. Together, these properties make this novel method a powerful tool for large-scale reprogramming of PBMCs and for iPSC biobanking.

  19. Comparison of hybrid Hall thruster model to experimental measurements

    NASA Astrophysics Data System (ADS)

    Scharfe, Michelle K.; Gascon, Nicolas; Cappelli, Mark A.; Fernandez, Eduardo

    2006-08-01

    A two-dimensional hybrid particle-in-cell numerical model has been constructed in the radial-axial plane with the intent of examining the physics governing Hall thruster operation. The electrons are treated as a magnetized quasi-one-dimensional fluid and the ions are treated as collisionless, unmagnetized discrete particles. The anomalously high electron conductivity experimentally observed in Hall thrusters is accounted for using experimental measurements of electron mobility in the Stanford Hall Thruster. While an experimental mobility results in improved simulation of electron temperature and electric potential relative to a Bohm-type model, results suggest that energy losses due to electron wall interactions may also be an important factor in accurately simulating plasma properties. Using a simplified electron wall damping model modified to produce general agreement with experimental measurements, an evaluation is made of differing treatments of electron mobility, background gas, neutral wall interactions, and charge exchange collisions. Although background gas results in two populations of neutrals, the increased neutral density has little effect on other plasma properties. Diffuse neutral wall interactions are in better agreement with experimental measurements than specular scattering. Also, charge exchange collisions result in an increase in average neutral velocity of 11% and a decrease in average ion velocity of 4% near the exit plane. The momentum exchange that occurs during charge exchange collisions is found to be negligible.

  20. The Effect of Advanced Motherhood on Newborn Offspring's Hippocampal Neural Stem Cell Proliferation

    PubMed Central

    Duan, Ping; Han, Xuefei

    2016-01-01

    Objective. To investigate the effect of advanced motherhood on rat hippocampal neural stem cell proliferation. Methods. Female parents were subdivided into control and old mother group by age, and neural stem cells were cultured from hippocampal tissues for 24 h newborn offspring. The diameter and numbers of neurospheres were examined by microscopy, and differences in proliferation were examined by EdU immunofluorescence, CCK-8 assay, and cell cycle analysis. Results. The number of neurospheres in the old mother group after culture was lower than the control group. Additionally, neurospheres' diameter was smaller than that of the control group (P < 0.05). The EdU positive rate of the old mother group was lower than that of the control group (P < 0.05). CCK-8 assay results showed that the absorbance values for the old mother group were lower than that of the control group at 48 h and 72 h (P < 0.05). The proportions of cells in the S and G2/M phases of the cell cycle for the older mother group were less than that found for the control group (P < 0.05). Conclusion. The proliferation rates of hippocampal NSCs seen in the older mother group were lower than that seen in the control group. PMID:27689086

  1. Final Report - Subfreezing Start/Stop Protocol for an Advanced Metallic Open Flowfield Fuel Cell Stack

    SciTech Connect

    Conti, Amedeo

    2010-09-28

    For fuel cells to be commercially viable as powerplants in automotive applications, the ability to survive and start reliably in cold climates (as low as -40C) is a must. Since fuel cells are water-based energy systems, this requirement is a significant technical challenge. Water transport studies are imperative for achieving DOE targets for fuel cell startup time from subfreezing conditions. Stack components must be selected that endure thermal and humidity cycling over the operating range, and operating strategies must be devised that enable the fuel cell to start, i.e. generate power and heat up sufficiently before ice extinguishes the galvanic reactions, and afford evacuation of a sufficient amount of water, using a limited amount of auxiliary power, at shutdown. The objective of the CIRRUS program was to advance the state of the art in fuel cell operability under subfreezing conditions, consistent with requirements for applications involving such conditions (e.g. automotive, forklifts, backup power systems, and APUs) and DOE targets, specifically to: • Demonstrate repeatable achievement of 50% rated power in less than 30 seconds from a -20C start condition, using less than 5 MJ auxiliary energy over the complete start/stop cycle. • Demonstrate unassisted start capability from an initial temperature of -40C.

  2. The Effect of Advanced Motherhood on Newborn Offspring's Hippocampal Neural Stem Cell Proliferation

    PubMed Central

    Duan, Ping; Han, Xuefei

    2016-01-01

    Objective. To investigate the effect of advanced motherhood on rat hippocampal neural stem cell proliferation. Methods. Female parents were subdivided into control and old mother group by age, and neural stem cells were cultured from hippocampal tissues for 24 h newborn offspring. The diameter and numbers of neurospheres were examined by microscopy, and differences in proliferation were examined by EdU immunofluorescence, CCK-8 assay, and cell cycle analysis. Results. The number of neurospheres in the old mother group after culture was lower than the control group. Additionally, neurospheres' diameter was smaller than that of the control group (P < 0.05). The EdU positive rate of the old mother group was lower than that of the control group (P < 0.05). CCK-8 assay results showed that the absorbance values for the old mother group were lower than that of the control group at 48 h and 72 h (P < 0.05). The proportions of cells in the S and G2/M phases of the cell cycle for the older mother group were less than that found for the control group (P < 0.05). Conclusion. The proliferation rates of hippocampal NSCs seen in the older mother group were lower than that seen in the control group.

  3. Targeting stem cell signaling pathways for drug discovery: advances in the Notch and Wnt pathways.

    PubMed

    An, Songzhu Michael; Ding, Qiang; Zhang, Jie; Xie, JingYi; Li, LingSong

    2014-06-01

    Signaling pathways transduce extracellular stimuli into cells through molecular cascades to regulate cellular functions. In stem cells, a small number of pathways, notably those of TGF-β/BMP, Hedgehog, Notch, and Wnt, are responsible for the regulation of pluripotency and differentiation. During embryonic development, these pathways govern cell fate specifications as well as the formation of tissues and organs. In adulthood, their normal functions are important for tissue homeostasis and regeneration, whereas aberrations result in diseases, such as cancer and degenerative disorders. In complex biological systems, stem cell signaling pathways work in concert as a network and exhibit crosstalk, such as the negative crosstalk between Wnt and Notch. Over the past decade, genetic and genomic studies have identified a number of potential drug targets that are involved in stem cell signaling pathways. Indeed, discovery of new targets and drugs for these pathways has become one of the most active areas in both the research community and pharmaceutical industry. Remarkable progress has been made and several promising drug candidates have entered into clinical trials. This review focuses on recent advances in the discovery of novel drugs which target the Notch and Wnt pathways.

  4. Quantum Hall effect in momentum space

    NASA Astrophysics Data System (ADS)

    Ozawa, Tomoki; Price, Hannah M.; Carusotto, Iacopo

    2016-05-01

    We theoretically discuss a momentum-space analog of the quantum Hall effect, which could be observed in topologically nontrivial lattice models subject to an external harmonic trapping potential. In our proposal, the Niu-Thouless-Wu formulation of the quantum Hall effect on a torus is realized in the toroidally shaped Brillouin zone. In this analogy, the position of the trap center in real space controls the magnetic fluxes that are inserted through the holes of the torus in momentum space. We illustrate the momentum-space quantum Hall effect with the noninteracting trapped Harper-Hofstadter model, for which we numerically demonstrate how this effect manifests itself in experimental observables. Extension to the interacting trapped Harper-Hofstadter model is also briefly considered. We finally discuss possible experimental platforms where our proposal for the momentum-space quantum Hall effect could be realized.

  5. Hall Opens Doors to Astronaut Heroes

    NASA Video Gallery

    Space shuttle astronauts Bonnie Dunbar, Curt Brown and Eileen Collins joined an elite group of American space heroes as they were inducted into the U.S. Astronaut Hall of Fame on April 20, during a...

  6. Boundary Effective Action for Quantum Hall States

    NASA Astrophysics Data System (ADS)

    Gromov, Andrey; Jensen, Kristan; Abanov, Alexander G.

    2016-03-01

    We consider quantum Hall states on a space with boundary, focusing on the aspects of the edge physics which are completely determined by the symmetries of the problem. There are four distinct terms of Chern-Simons type that appear in the low-energy effective action of the state. Two of these protect gapless edge modes. They describe Hall conductance and, with some provisions, thermal Hall conductance. The remaining two, including the Wen-Zee term, which contributes to the Hall viscosity, do not protect gapless edge modes but are instead related to the local boundary response fixed by symmetries. We highlight some basic features of this response. It follows that the coefficient of the Wen-Zee term can change across an interface without closing a gap or breaking a symmetry.

  7. The phonon Hall effect: theory and application.

    PubMed

    Zhang, Lifa; Ren, Jie; Wang, Jian-Sheng; Li, Baowen

    2011-08-01

    We present a systematic theory of the phonon Hall effect in a ballistic crystal lattice system, and apply it on the kagome lattice which is ubiquitous in various real materials. By proposing a proper second quantization for the non-Hermitian in the polarization-vector space, we obtain a new heat current density operator with two separate contributions: the normal velocity responsible for the longitudinal phonon transport, and the anomalous velocity manifesting itself as the Hall effect of transverse phonon transport. As exemplified in kagome lattices, our theory predicts that the direction of Hall conductivity at low magnetic field can be reversed by tuning the temperatures, which we hope can be verified by experiments in the future. Three phonon-Hall-conductivity singularities induced by phonon-band-topology change are discovered as well, which correspond to the degeneracies at three different symmetric center points, Γ, K, X, in the wavevector space of the kagome lattice.

  8. Quantum anomalous Hall effect with higher plateaus.

    PubMed

    Wang, Jing; Lian, Biao; Zhang, Haijun; Xu, Yong; Zhang, Shou-Cheng

    2013-09-27

    The quantum anomalous Hall (QAH) effect in magnetic topological insulators is driven by the combination of spontaneous magnetic moments and spin-orbit coupling. Its recent experimental discovery raises the question if higher plateaus can also be realized. Here, we present a general theory for a QAH effect with higher Chern numbers and show by first-principles calculations that a thin film magnetic topological insulator of Cr-doped Bi2(Se,Te)3 is a candidate for the C=2 QAH insulator. Remarkably, whereas a higher magnetic field leads to lower Hall conductance plateaus in the integer quantum Hall effect, a higher magnetic moment leads to higher Hall conductance plateaus in the QAH effect.

  9. Hall viscosity revealed via density response

    NASA Astrophysics Data System (ADS)

    Huang, Biao

    2015-06-01

    Quantum Hall systems have recently been shown to possess a quantity sensitive to the spatial geometry and topology of the system, dubbed the Hall viscosity ηH. Despite the extensive theoretical discussions on its properties, the question of how to measure ηH still poses a challenge. In this paper, we present a general relation between Hall viscosity and susceptibility for systems with Galilean invariance. Thus, it allows for determination of ηH through density response signatures. The relations are verified in the integer quantum Hall example and are further illustrated in an effective hydrodynamic analysis. Since the derivation is based on Kubo formulas and assumes no more than conservation laws and translational symmetry, the results are applicable to a wide range of systems.

  10. Protecting Your Residence Hall Furniture Investment.

    ERIC Educational Resources Information Center

    Wiens, Janet

    2003-01-01

    Asserting that residence hall furniture takes abuse simply through use, discusses a three-part approach--student involvement and education, creating the right environment, and ongoing maintenance--that helps reduce normal wear and tear. (EV)

  11. Boundary Effective Action for Quantum Hall States.

    PubMed

    Gromov, Andrey; Jensen, Kristan; Abanov, Alexander G

    2016-03-25

    We consider quantum Hall states on a space with boundary, focusing on the aspects of the edge physics which are completely determined by the symmetries of the problem. There are four distinct terms of Chern-Simons type that appear in the low-energy effective action of the state. Two of these protect gapless edge modes. They describe Hall conductance and, with some provisions, thermal Hall conductance. The remaining two, including the Wen-Zee term, which contributes to the Hall viscosity, do not protect gapless edge modes but are instead related to the local boundary response fixed by symmetries. We highlight some basic features of this response. It follows that the coefficient of the Wen-Zee term can change across an interface without closing a gap or breaking a symmetry. PMID:27058090

  12. Hall effect degradation of rail gun performance

    NASA Astrophysics Data System (ADS)

    Witalis, E. A.; Gunnarsson, Patrik

    1993-01-01

    The paper discusses the Hall effect and shows it to be significant in the low-density and high-field trailing part of a plasma armature. Without the Hall effect a simple armature model is derived. It exhibits properties expected from classical MHD theory and shows that the purely relativistic electric charge buildup on the rails is a fundamental gun property, leading to V(breech) = 1.5 V(muzzle). The mathematics involved in accounting for Hall effect phenomena is described. These are of two types: the Hall-skewing of the armature current and the superimposed plasma flow rotation. For decreasing gun current the two effects efficiently combine to eject armature plasma rearwards, thus creating conditions for arc separation and parasitic arcs.

  13. Boundary Effective Action for Quantum Hall States.

    PubMed

    Gromov, Andrey; Jensen, Kristan; Abanov, Alexander G

    2016-03-25

    We consider quantum Hall states on a space with boundary, focusing on the aspects of the edge physics which are completely determined by the symmetries of the problem. There are four distinct terms of Chern-Simons type that appear in the low-energy effective action of the state. Two of these protect gapless edge modes. They describe Hall conductance and, with some provisions, thermal Hall conductance. The remaining two, including the Wen-Zee term, which contributes to the Hall viscosity, do not protect gapless edge modes but are instead related to the local boundary response fixed by symmetries. We highlight some basic features of this response. It follows that the coefficient of the Wen-Zee term can change across an interface without closing a gap or breaking a symmetry.

  14. Haematopoietic cell transplantation for acute leukaemia and advanced myelodysplastic syndrome in Fanconi anaemia.

    PubMed

    Mitchell, Richard; Wagner, John E; Hirsch, Betsy; DeFor, Todd E; Zierhut, Heather; MacMillan, Margaret L

    2014-02-01

    Acute leukaemia or advanced myelodysplastic syndrome (MDS ≥ 5% blasts) in Fanconi anaemia (FA) patients is associated with a poor prognosis. We report 21 FA patients with acute leukaemia or advanced MDS who underwent haematopoietic cell transplantation (HCT) at the University of Minnesota between 1988 and 2011. Six patients had biallelic BRCA2 mutations. Eight patients received pre-transplant cytoreduction, with 3 achieving complete remission. HCT donor source included human leucocyte antigen-matched sibling (n = 2) or alternative donors (n = 19). Neutrophil engraftment was 95% for the entire cohort, and the incidence of acute graft-versus-host disease was 19%. 5-year overall survival (OS) was 33%, with a relapse rate of 24%, with similar OS in patients with biallelic BRCA2 mutations. Our study supports the use of HCT in the treatment of FA patients with acute leukaemia or advanced MDS, however, the role of chemotherapy prior to HCT remains unclear for this population. FA patients with biallelic BRCA2 are unique and may benefit from higher dose chemotherapy relative to other complementation groups.

  15. Naval Research Laboratory's programs in advanced indium phosphide solar cell development

    NASA Astrophysics Data System (ADS)

    Summers, Geoffrey P.

    1995-10-01

    The Naval Research Laboratory has been involved in developing InP solar cell technology since 1988. The purpose of these programs was to produce advanced cells for use in very high radiation environments, either as a result of operating satellites in the Van Allen belts or for very long duration missions in other orbits. Richard Statler was technical representative on the first program, with Spire Corporation as the contractor, which eventually produced several hundred, high efficiency 2 x 2 sq cm single crystal InP cells. The shallow homojunction technology which was developed in this program enabled cells to be made with AMO, one sun efficiencies greater than 19%. Many of these cells have been flown on space experiments, including PASP Plus, which have confirmed the high radiation resistance of InP cells. NRL has also published widely on the radiation response of these cells and also on radiation-induced defect levels detected by DLTS, especially the work of Rob Walters and Scott Messenger. In 1990 NRL began another Navy-sponsored program with Tim Coutts and Mark Wanlass at the National Renewable Energy Laboratory (NREL), to develop a one sun, two terminal space version of the InP-InGaAs tandem junction cell being investigated at NREL for terrestrial applications. These cells were grown on InP substrates. Several cells with AM0, one sun efficiencies greater than 22% were produced. Two 2 x 2 sq cm cells were incorporated on the STRV lA/B solar cell experiment. These were the only two junction, tandem cells on the STRV experiment. The high cost and relative brittleness of InP wafers meant that if InP cell technology were to become a viable space power source, the superior radiation resistance of InP would have to be combined with a cheaper and more robust substrate. The main technical challenge was to overcome the effect of the dislocations produced by the lattice mismatch at the interface of the two materials. Over the last few years, NRL and Steve Wojtczuk at

  16. Naval Research Laboratory's programs in advanced indium phosphide solar cell development

    NASA Technical Reports Server (NTRS)

    Summers, Geoffrey P.

    1995-01-01

    The Naval Research Laboratory has been involved in developing InP solar cell technology since 1988. The purpose of these programs was to produce advanced cells for use in very high radiation environments, either as a result of operating satellites in the Van Allen belts or for very long duration missions in other orbits. Richard Statler was technical representative on the first program, with Spire Corporation as the contractor, which eventually produced several hundred, high efficiency 2 x 2 sq cm single crystal InP cells. The shallow homojunction technology which was developed in this program enabled cells to be made with AMO, one sun efficiencies greater than 19%. Many of these cells have been flown on space experiments, including PASP Plus, which have confirmed the high radiation resistance of InP cells. NRL has also published widely on the radiation response of these cells and also on radiation-induced defect levels detected by DLTS, especially the work of Rob Walters and Scott Messenger. In 1990 NRL began another Navy-sponsored program with Tim Coutts and Mark Wanlass at the National Renewable Energy Laboratory (NREL), to develop a one sun, two terminal space version of the InP-InGaAs tandem junction cell being investigated at NREL for terrestrial applications. These cells were grown on InP substrates. Several cells with AM0, one sun efficiencies greater than 22% were produced. Two 2 x 2 sq cm cells were incorporated on the STRV lA/B solar cell experiment. These were the only two junction, tandem cells on the STRV experiment. The high cost and relative brittleness of InP wafers meant that if InP cell technology were to become a viable space power source, the superior radiation resistance of InP would have to be combined with a cheaper and more robust substrate. The main technical challenge was to overcome the effect of the dislocations produced by the lattice mismatch at the interface of the two materials. Over the last few years, NRL and Steve Wojtczuk at

  17. Advances in Neurotrophic Factor and Cell-Based Therapies for Parkinson's Disease: A Mini-Review.

    PubMed

    Staudt, Michael D; Di Sebastiano, Andrea R; Xu, Hu; Jog, Mandar; Schmid, Susanne; Foster, Paula; Hebb, Matthew O

    2016-01-01

    Parkinson's disease (PD) affects an estimated 7-10 million people worldwide and remains without definitive or disease-modifying treatment. There have been many recent developments in cell-based therapy (CBT) to replace lost circuitry and provide chronic biological sources of therapeutic agents to the PD-affected brain. Early neural transplantation studies underscored the challenges of immune compatibility, graft integration and the need for renewable, autologous graft sources. Neurotrophic factors (NTFs) offer a potential class of cytoprotective pharmacotherapeutics that may complement dopamine (DA) replacement and CBT strategies in PD. Chronic NTF delivery may be an integral goal of CBT, with grafts consisting of autologous drug-producing (e.g., DA, NTF) cells that are capable of integration and function in the host brain. In this mini-review, we outline the past experience and recent advances in NTF technology and CBT as promising and integrated approaches for the treatment of PD. PMID:26330171

  18. White paper on how to go forward with cell-based advanced therapies in Europe.

    PubMed

    Erben, Reinhold G; Silva-Lima, Beatriz; Reischl, Ilona; Steinhoff, Gustav; Tiedemann, Gudrun; Dalemans, Wilfried; Vos, Alexander; Janssen, Rob T A; Le Blanc, Katarina; van Osch, Gerjo J V M; Luyten, Frank P

    2014-10-01

    The current White paper summarizes the discussions and exchange of experiences during the first European Interdisciplinary Summit on Cell-Based ATMPs held in Vienna, Austria, May 02-03, 2013. The meeting was supported by the Research Networking Programme REMEDIC (regenerative medicine) funded by the European Science Foundation and by the British Medical Research Council. To improve the competitiveness of Europe in the field of cell-based Advanced Medicinal Therapy Products (ATMPs), the following key issues were identified during the meeting: removal of national hurdles in the European Union, harmonization of national and subnational differences in Hospital Exemption rules, improved treatment algorithms for reimbursement, better knowledge on the mode of action, predictive preclinical efficacy and safety testing, need for innovative systems for preclinical testing, appropriate product characterization, manufacturing with cost of goods in mind, and appropriate design of clinical trials.

  19. Stem cell therapies for amyotrophic lateral sclerosis: Recent advances and prospects for the future

    PubMed Central

    Lunn, J. Simon; Sakowski, Stacey A.; Feldman, Eva L.

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a lethal disease involving the loss of motor neurons. Although the mechanisms responsible for motor neuron degeneration in ALS remain elusive, the development of stem cell-based therapies for the treatment of ALS has gained widespread support. Here, we review the types of stem cells being considered for therapeutic applications in ALS, and emphasize recent preclinical advances that provide supportive rationale for clinical translation. We also discuss early trials from around the world translating cellular therapies to ALS patients, and offer important considerations for future clinical trial design. Although clinical translation is still in its infancy, and additional insight into the mechanisms underlying therapeutic efficacy and the establishment of long-term safety are required, these studies represent an important first step towards the development of effective cellular therapies for the treatment of ALS. PMID:24448926

  20. Concise review: Stem cell therapies for amyotrophic lateral sclerosis: recent advances and prospects for the future.

    PubMed

    Lunn, J Simon; Sakowski, Stacey A; Feldman, Eva L

    2014-05-01

    Amyotrophic lateral sclerosis (ALS) is a lethal disease involving the loss of motor neurons. Although the mechanisms responsible for motor neuron degeneration in ALS remain elusive, the development of stem cell-based therapies for the treatment of ALS has gained widespread support. Here, we review the types of stem cells being considered for therapeutic applications in ALS, and emphasize recent preclinical advances that provide supportive rationale for clinical translation. We also discuss early trials from around the world translating cellular therapies to ALS patients, and offer important considerations for future clinical trial design. Although clinical translation is still in its infancy, and additional insight into the mechanisms underlying therapeutic efficacy and the establishment of long-term safety are required, these studies represent an important first step toward the development of effective cellular therapies for the treatment of ALS.

  1. Fractional Quantum Hall Effects in a Two-Dimensional Atomic Gas

    NASA Astrophysics Data System (ADS)

    Zhao, Jianshi; Jacome, Louis; Gemelke, Nathan

    2014-03-01

    Fractional Hall effects in two-dimensional electron gases have dramatically altered the way we look at ordering in quantum many body systems. Despite heroic advances since their discovery, many predictions regarding unique behavior have yet to be observed. We describe new efforts to produce similar effects in cold atomic Bose gases. Previous experiments have observed strong correlation in large ensembles of rapidly rotating few body samples consistent with a description using bosonic analogues of fractional hall states. We describe extensions of these experiments to observe individual systems in a quantum gas micropscope, introduce strong interactions through Feshbach resonance, and extend effects to larger numbers of atoms. The use of impurity atoms to probe fractional hall droplets will also be discussed, as will the extension of these effects to higher spin samples by using multiple internal states of Rubidium-87.

  2. Galilean invariance at quantum Hall edge

    NASA Astrophysics Data System (ADS)

    Moroz, Sergej; Hoyos, Carlos; Radzihovsky, Leo

    2015-05-01

    We construct the theory of a chiral Luttinger liquid that lives on the boundary of a Galilean invariant quantum Hall fluid. In contrast to previous studies, Galilean invariance of the total (bulk plus edge) theory is guaranteed. We consider electromagnetic response at the edge and calculate momentum- and frequency-dependent electric conductivity and argue that its experimental measurement can provide a new means to determine the "shift" and bulk Hall viscosity.

  3. Quantum hall effect at low magnetic fields

    PubMed

    Huckestein

    2000-04-01

    The temperature and scale dependence of resistivities in the standard scaling theory of the integer quantum Hall effect is discussed. It is shown that recent experiments, claiming to observe a discrepancy with the global phase diagram of the quantum Hall effect, are in fact in agreement with the standard theory. The apparent low-field transition observed in the experiments is identified as a crossover due to weak localization and a strong reduction of the conductivity when Landau quantization becomes dominant.

  4. Energy magnetization and the thermal Hall effect.

    PubMed

    Qin, Tao; Niu, Qian; Shi, Junren

    2011-12-01

    We obtain a set of general formulas for determining magnetizations, including the usual electromagnetic magnetization as well as the gravitomagnetic energy magnetization. The magnetization corrections to the thermal transport coefficients are explicitly demonstrated. Our theory provides a systematic approach for properly evaluating the thermal transport coefficients of magnetic systems, eliminating the unphysical divergence from the direct application of the Kubo formula. For a noninteracting anomalous Hall system, the corrected thermal Hall conductivity obeys the Wiedemann-Franz law.

  5. Integer quantum Hall effect for bosons.

    PubMed

    Senthil, T; Levin, Michael

    2013-01-25

    A simple physical realization of an integer quantum Hall state of interacting two dimensional bosons is provided. This is an example of a symmetry-protected topological (SPT) phase which is a generalization of the concept of topological insulators to systems of interacting bosons or fermions. Universal physical properties of the boson integer quantum Hall state are described and shown to correspond with those expected from general classifications of SPT phases.

  6. CELL THERAPY FOR INTERVERTEBRAL DISC REPAIR: ADVANCING CELL THERAPY FROM BENCH TO CLINICS

    PubMed Central

    Benneker, L.M.; Andersson, G.; Iatridis, J.C.; Sakai, D.; Härtl, R.; Ito, K.; Grad, S.

    2016-01-01

    Intervertebral disc (IVD) degeneration is a major cause of pain and disability; yet therapeutic options are limited and treatment often remains unsatisfactory. In recent years, research activities have intensified in tissue engineering and regenerative medicine, and pre-clinical studies have demonstrated encourageing results. Nonetheless, the translation of new biological therapies into clinical practice faces substantial barriers. During the symposium “Where Science meets Clinics”, sponsored by the AO Foundation and held in Davos, Switzerland, from September 5–7, 2013, hurdles for translation were outlined, and ways to overcome them were discussed. With respect to cell therapy for IVD repair, it is obvious that regenerative treatment is indicated at early stages of disc degeneration, before structural changes have occurred. It is envisaged that in the near future, screening techniques and non-invasive imageing methods will be available to detect early degenerative changes. The promises of cell therapy include a sustained effect on matrix synthesis, inflammation control, and prevention of angio- and neurogenesis. Discogenic pain, originating from “black discs” or annular injury, prevention of adjacent segment disease, and prevention of post-discectomy syndrome were identified as prospective indications for cell therapy. Before such therapy can safely and effectively be introduced into clinics, the identification of the patient population and proper standardisation of diagnostic parameters and outcome measurements are indispensable. Furthermore, open questions regarding the optimal cell type and delivery method need to be resolved in outline order to overcome the safety concerns implied with certain procedures. Finally, appropriate large animal models and well-designed clinical studies will be required, particularly addressing safety aspects. PMID:24802611

  7. Recombinant interferon alfa-2a, an active agent in advanced cutaneous T-cell lymphomas.

    PubMed

    Bunn, P A; Ihde, D C; Foon, K A

    1987-01-01

    The cutaneous T-cell lymphomas including mycosis fungoides and the Sézary syndrome, are indolent lymphomas with early systemic dissemination. Like the indolent B-cell lymphomas, they cannot be cured by currently available systemic chemotherapy so new systemic therapies need to be developed. A study of very high-dose recombinant interferon alfa-2a was, therefore, initiated in 20 patients with advanced cutaneous T-cell lymphoma (5 in stage II, 2 in stage III and 13 in stage IV). All patients were refractory to at least 2 standard therapies, including topical nitrogen mustard (18 patients), psoralens and ultraviolet A light (12 patients), total skin electron irradiation (14 patients) and systemic chemotherapy (16 patients). Nine out of 20 patients (45%; 95% confidence interval 25-69%) had either objective partial or complete responses within 3 months of starting treatment. Maximal response, however, often did not occur for at least one year. The median duration of response was 5.5 months and all complete responses lasted more than 2 years. Response frequencies were equal at both cutaneous and extracutaneous sites and in patients with or without prior chemotherapy. Toxicity was exhibited primarily as a flu-like syndrome consisting of fever, malaise, fatigue, anorexia and weight loss which necessitated dose reductions in all patients. Transient elevations in liver function and decreases in renal function and granulocyte counts occurred in some patients. It is concluded that interferon alfa-2a is highly active against advanced cutaneous T-cell lymphomas and that it should be studied in its early stages. It should also be evaluated in combination with other biological agents and with chemotherapy.

  8. Observation of a superfluid Hall effect

    PubMed Central

    Jiménez-García, Karina; Williams, Ross A.; Beeler, Matthew C.; Perry, Abigail R.; Phillips, William D.; Spielman, Ian B.

    2012-01-01

    Measurement techniques based upon the Hall effect are invaluable tools in condensed-matter physics. When an electric current flows perpendicular to a magnetic field, a Hall voltage develops in the direction transverse to both the current and the field. In semiconductors, this behavior is routinely used to measure the density and charge of the current carriers (electrons in conduction bands or holes in valence bands)—internal properties of the system that are not accessible from measurements of the conventional resistance. For strongly interacting electron systems, whose behavior can be very different from the free electron gas, the Hall effect’s sensitivity to internal properties makes it a powerful tool; indeed, the quantum Hall effects are named after the tool by which they are most distinctly measured instead of the physics from which the phenomena originate. Here we report the first observation of a Hall effect in an ultracold gas of neutral atoms, revealed by measuring a Bose–Einstein condensate’s transport properties perpendicular to a synthetic magnetic field. Our observations in this vortex-free superfluid are in good agreement with hydrodynamic predictions, demonstrating that the system’s global irrotationality influences this superfluid Hall signal. PMID:22699494

  9. Hierarchical nature of the quantum Hall effects.

    PubMed

    Bonderson, Parsa

    2012-02-10

    I demonstrate that the wave function for a ν=n+ν[over ˜] quantum Hall state with Landau levels 0,1,…,n-1 filled and a filling fraction ν[over ˜] quantum Hall state with 0<ν[over ˜]≤1 in the nth Landau level can be obtained hierarchically from the ν=n state by introducing quasielectrons which are then projected into the (conjugate of the) ν[over ˜] state. In particular, the ν[over ˜]=1 case produces the filled Landau level wave functions hierarchically, thus establishing the hierarchical nature of the integer quantum Hall states. It follows that the composite fermion description of fractional quantum Hall states fits within the hierarchy theory of the fractional quantum Hall effect. I also demonstrate this directly by generating the composite fermion ground-state wave functions via application of the hierarchy construction to fractional quantum Hall states, starting from the ν=1/m Laughlin states.

  10. Observation of a superfluid Hall effect.

    PubMed

    LeBlanc, Lindsay J; Jiménez-García, Karina; Williams, Ross A; Beeler, Matthew C; Perry, Abigail R; Phillips, William D; Spielman, Ian B

    2012-07-01

    Measurement techniques based upon the Hall effect are invaluable tools in condensed-matter physics. When an electric current flows perpendicular to a magnetic field, a Hall voltage develops in the direction transverse to both the current and the field. In semiconductors, this behavior is routinely used to measure the density and charge of the current carriers (electrons in conduction bands or holes in valence bands)--internal properties of the system that are not accessible from measurements of the conventional resistance. For strongly interacting electron systems, whose behavior can be very different from the free electron gas, the Hall effect's sensitivity to internal properties makes it a powerful tool; indeed, the quantum Hall effects are named after the tool by which they are most distinctly measured instead of the physics from which the phenomena originate. Here we report the first observation of a Hall effect in an ultracold gas of neutral atoms, revealed by measuring a Bose-Einstein condensate's transport properties perpendicular to a synthetic magnetic field. Our observations in this vortex-free superfluid are in good agreement with hydrodynamic predictions, demonstrating that the system's global irrotationality influences this superfluid Hall signal.

  11. Emphysema requires the receptor for advanced glycation end-products triggering on structural cells.

    PubMed

    Waseda, Koichi; Miyahara, Nobuaki; Taniguchi, Akihiko; Kurimoto, Etsuko; Ikeda, Genyo; Koga, Hikari; Fujii, Utako; Yamamoto, Yasuhiko; Gelfand, Erwin W; Yamamoto, Hiroshi; Tanimoto, Mitsune; Kanehiro, Arihiko

    2015-04-01

    Pulmonary emphysema is characterized by persistent inflammation and progressive alveolar destruction. The receptor for advanced glycation end-products (RAGE) is a multiligand cell surface receptor reported to be involved in the process of acute alveolar epithelial cell injury. However, studies that address the role of RAGE in pulmonary emphysema are inconclusive. We investigated the role of RAGE in the development of elastase-induced pulmonary inflammation and emphysema in mice. RAGE-sufficient (RAGE(+/+)) mice and RAGE-deficient (RAGE(-/-)) mice were treated with intratracheal elastase on Day 0. Airway inflammation, static lung compliance, lung histology, and the levels of neutrophil-related chemokine and proinflammatory cytokines in bronchoalveolar lavage fluid were determined on Days 4 and 21. Neutrophilia in bronchoalveolar lavage fluid, seen in elastase-treated RAGE(+/+) mice, was reduced in elastase-treated RAGE(-/-) mice on Day 4, and was associated with decreased levels of keratinocyte chemoattractant, macrophage inflammatory protein-2, and IL-1β. Static lung compliance values and emphysematous changes in the lung tissue were decreased in RAGE(-/-) mice compared with RAGE(+/+) mice on Day 21 after elastase treatment. Experiments using irradiated, bone marrow-chimeric mice showed that the mice expressing RAGE on radioresistant structural cells, but not hematopoietic cells, developed elastase-induced neutrophilia and emphysematous change in the lung. In contrast, mice expressing RAGE on hematopoietic cells, but not radioresistant structural cells, showed reduced neutrophilia and emphysematous change in the lung. These data identify the importance of RAGE expressed on lung structural cells in the development of elastase-induced pulmonary inflammation and emphysema. Thus, RAGE represents a novel therapeutic target for preventing pulmonary emphysema.

  12. Sildenafil Ameliorates Advanced Glycation End Products-Induced Mitochondrial Dysfunction in HT-22 Hippocampal Neuronal Cells

    PubMed Central

    Sung, Soon Ki; Woo, Jae Suk; Kim, Young Ha; Son, Dong Wuk; Lee, Sang Weon

    2016-01-01

    Objective Accumulation of advanced glycation end-products (AGE) and mitochondrial glycation is importantly implicated in the pathological changes of the brain associated with diabetic complications, Alzheimer disease, and aging. The present study was undertaken to determine whether sildenafil, a type 5 phosphodiesterase type (PDE-5) inhibitor, has beneficial effect on neuronal cells challenged with AGE-induced oxidative stress to preserve their mitochondrial functional integrity. Methods HT-22 hippocampal neuronal cells were exposed to AGE and changes in the mitochondrial functional parameters were determined. Pretreatment of cells with sildenafil effectively ameliorated these AGE-induced deterioration of mitochondrial functional integrity. Results AGE-treated cells lost their mitochondrial functional integrity which was estimated by their MTT reduction ability and intracellular ATP concentration. These cells exhibited stimulated generation of reactive oxygen species (ROS), disruption of mitochondrial membrane potential, induction of mitochondrial permeability transition, and release of the cytochrome C, activation of the caspase-3 accompanied by apoptosis. Western blot analyses and qRT-PCR demonstrated that sildenafil increased the expression level of the heme oxygenase-1 (HO-1). CoPP and bilirubin, an inducer of HO-1 and a metabolic product of HO-1, respectively, provided a similar protective effects. On the contrary, the HO-1 inhibitor ZnPP IX blocked the effect of sildenafil. Transfection with HO-1 siRNA significantly reduced the protective effect of sildenafil on the loss of MTT reduction ability and MPT induction in AGE-treated cells. Conclusion Taken together, our results suggested that sildenafil provides beneficial effect to protect the HT-22 hippocampal neuronal cells against AGE-induced deterioration of mitochondrial integrity, and upregulation of HO-1 is involved in the underlying mechanism. PMID:27226858

  13. Advances in using MRI probes and sensors for in vivo cell tracking as applied to regenerative medicine

    PubMed Central

    Srivastava, Amit K.; Kadayakkara, Deepak K.; Bar-Shir, Amnon; Gilad, Assaf A.; McMahon, Michael T.; Bulte, Jeff W. M.

    2015-01-01

    The field of molecular and cellular imaging allows molecules and cells to be visualized in vivo non-invasively. It has uses not only as a research tool but in clinical settings as well, for example in monitoring cell-based regenerative therapies, in which cells are transplanted to replace degenerating or damaged tissues, or to restore a physiological function. The success of such cell-based therapies depends on several critical issues, including the route and accuracy of cell transplantation, the fate of cells after transplantation, and the interaction of engrafted cells with the host microenvironment. To assess these issues, it is necessary to monitor transplanted cells non-invasively in real-time. Magnetic resonance imaging (MRI) is a tool uniquely suited to this task, given its ability to image deep inside tissue with high temporal resolution and sensitivity. Extraordinary efforts have recently been made to improve cellular MRI as applied to regenerative medicine, by developing more advanced contrast agents for use as probes and sensors. These advances enable the non-invasive monitoring of cell fate and, more recently, that of the different cellular functions of living cells, such as their enzymatic activity and gene expression, as well as their time point of cell death. We present here a review of recent advancements in the development of these probes and sensors, and of their functioning, applications and limitations. PMID:26035841

  14. The pancreatic beta cell as a paradigm for advances in inositide research.

    PubMed

    Barker, Christopher J; Berggren, Per-Olof

    2012-09-01

    In a previous review for Advances in Enzyme Research (Berggren and Barker, 2008) we outlined the history of our involvement in discovering important roles for inositides in the insulin secreting pancreatic beta cell. In this current appraisal we bring the work up to date and project how we believe this field will continue to develop in the future. Recently, we have seen an important synergism between the growth in our understanding of inositide function and our knowledge of beta cell stimulus-secretion coupling in both physiological and pathophysiological contexts. Important advances have been made in three areas. 1. The classic regulation of cytoplasmic free Ca(2+) concentration [Ca(2+)](i) by Inositol 1,4,5-trisphosphate (Ins(1,4,5)P(3)) and its receptor, 2. A novel role of the inositol pyrophosphates, especially 5-diphosphoinositol pentakisphosphate (5-PP-InsP(5)), in exocytosis, and 3. The unique signaling roles of PI3K pathways instituted by the engagement of the insulin receptor in an autocrine, positive feed-back loop. We examine each of these in turn and close with an assessment of the likely future directions the research will take.

  15. In utero stem cell transplantation and gene therapy: rationale, history, and recent advances toward clinical application

    PubMed Central

    Almeida-Porada, Graça; Atala, Anthony; Porada, Christopher D

    2016-01-01

    Recent advances in high-throughput molecular testing have made it possible to diagnose most genetic disorders relatively early in gestation with minimal risk to the fetus. These advances should soon allow widespread prenatal screening for the majority of human genetic diseases, opening the door to the possibility of treatment/correction prior to birth. In addition to the obvious psychological and financial benefits of curing a disease in utero, and thereby enabling the birth of a healthy infant, there are multiple biological advantages unique to fetal development, which provide compelling rationale for performing potentially curative treatments, such as stem cell transplantation or gene therapy, prior to birth. Herein, we briefly review the fields of in utero transplantation (IUTx) and in utero gene therapy and discuss the biological hurdles that have thus far restricted success of IUTx to patients with immunodeficiencies. We then highlight several recent experimental breakthroughs in immunology, hematopoietic/marrow ontogeny, and in utero cell delivery, which have collectively provided means of overcoming these barriers, thus setting the stage for clinical application of these highly promising therapies in the near future. PMID:27069953

  16. Prognostic significance of CT-emphysema score in patients with advanced squamous cell lung cancer

    PubMed Central

    Kim, Young Saing; Ahn, Hee Kyung; Cho, Eun Kyung; Jeong, Yu Mi; Kim, Jeong Ho

    2016-01-01

    Background Although emphysema is a known independent risk factor of lung cancer, no study has addressed the prognostic impact of computed tomography (CT)-emphysema score in advanced stage lung cancer. Methods For 84 consecutive patients with stage IIIB and IV squamous cell lung cancer that underwent palliative chemotherapy, severity of emphysema was semi-quantitatively scored using baseline chest CT images according to the Goddard scoring system (possible scores range, 0–24). The cutoff of high CT-emphysema score was determined using the maximum chi-squared test and the prognostic significance of the high CT-emphysema score was evaluated using Kaplan-Meier analysis and Cox proportional hazards analysis. Results The median CT-emphysema score was 5 (range, 0–22). Patients with a high CT-emphysema score (≥4) tended to have poorer overall survival (OS) (median: 6.3 vs. 13.7 months) than those with a score of <4 (P=0.071). Multivariable analysis revealed that a higher CT-emphysema score was a significant independent prognostic factor for poor OS [hazard ratio (HR) =2.06; 95% confidence interval (CI), 1.24–3.41; P=0.005), along with no response to first-line therapy (P=0.009) and no second-line therapy (P<0.001). Conclusions CT-emphysema score is significantly associated with poor prognosis in patients with advanced squamous cell lung cancer. PMID:27621848

  17. Chemotherapy in elderly patients with advanced non-small cell lung cancer.

    PubMed

    Quoix, Elisabeth; Westeel, Virginie; Zalcman, Gérard; Milleron, Bernard

    2011-12-01

    Because of increasing life expectancy and of higher risk of cancer with ageing, lung cancer in elderly is a frequent disease. For a long time nihilism influenced treatment decisions in elderly patients with advanced non-small cell lung cancer. Since the beginning of the last decade single agent chemotherapy has been accepted as standard of care, vinorelbine and gemcitabine being the most frequently used drugs in Europe and US, docetaxel in Japan. Platinum-based doublets have been shown to be superior to monotherapy in young and fit patients with advanced non-small cell lung cancer. Although there were some indications from subgroup analyses of clinical trials not specifically dedicated to elderly patients that a platinum-based doublet might also benefit to older patients, there was no definitive proof of concept until ASCO meeting 2010. At this meeting results of a phase 3 trial showed that PS 0-2 patients, aged 70-89 years drove a significant benefit from a treatment with carboplatin associated to weekly paclitaxel compared to a monotherapy. Thus, the paradigm of treatment in elderly patients should perhaps be modified from a single agent to doublet chemotherapy. Whether other platinum-based doublets would provide the same benefit as the specific one studied remains to be evaluated. PMID:21893363

  18. Neoadjuvant chemoradiotherapy followed by surgery in locally advanced squamous cell carcinoma of the vulva

    PubMed Central

    GAUDINEAU, A.; WEITBRUCH, D.; QUETIN, P.; HEYMANN, S.; PETIT, T.; VOLKMAR, P.; BODIN, F.; VELTEN, M.; RODIER, J.F.

    2012-01-01

    Alternative therapies have been sought to alleviate mutilation and morbidity associated with surgery for vulvar neoplasms. Our prime objective was to assess tumor absence in pathological vulvar and nodal specimens following neoadjuvant chemoradiotherapy in locally advanced vulvar neoplasms. Data were retrospectively collected from January 2001 to May 2009 from 22 patients treated with neoadjuvant therapy for locally advanced squamous cell carcinoma of the vulva. Neoadjuvant treatment consisted of inguino-pelvic radiotherapy (50 Gy) in association with chemotherapy when possible. Surgery occurred at intervals of between 5 to 8 weeks. The median age of patients at diagnosis was 74.1 years. All patients were primarily treated with radiotherapy and 15 received a concomitant chemotherapy. Additionally, all patients underwent radical vulvectomy and bilateral inguino-femoral lymphadenectomy. Tumor absence in the vulvar and nodal pathological specimens was achieved for 6 (27%) patients, while absence in the vulvar pathological specimens was only achieved for 10 (45.4%) patients. Postoperative follow-up revealed breakdown of groin wounds, vulvar wounds and chronic lymphedema in 3 (14.3%), 7 (31.8%) and 14 cases (63.6%), respectively. Within a median follow-up time of 2.3 years [interquartile range (IQR), 0.6–4.6], 12 (54.6%) patients experienced complete remission and 6 cases succumbed to metastatic evolution within a median of 2.2 years (IQR, 0.6–4.6), with 1 case also experiencing perineal recurrence. Median survival time, estimated using the Kaplan-Meier method, was 5.1 years (IQR, 1.0–6.8). We suggest that neoadjuvant chemoradiotherapy may represent a reliable and promising strategy in locally advanced squamous cell carcinoma of the vulva. PMID:23205089

  19. Veliparib, Cisplatin, and Gemcitabine Hydrochloride in Treating Patients With Advanced Biliary, Pancreatic, Urothelial, or Non-Small Cell Lung Cancer

    ClinicalTrials.gov

    2013-07-01

    Advanced Adult Primary Liver Cancer; Localized Unresectable Adult Primary Liver Cancer; Metastatic Transitional Cell Cancer of the Renal Pelvis and Ureter; Regional Transitional Cell Cancer of the Renal Pelvis and Ureter; Stage III Bladder Cancer; Stage III Pancreatic Cancer; Stage IIIA Non-small Cell Lung Cancer; Stage IIIB Non-small Cell Lung Cancer; Stage IV Bladder Cancer; Stage IV Non-small Cell Lung Cancer; Stage IV Pancreatic Cancer; Transitional Cell Carcinoma of the Bladder; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer

  20. What We Have Learned By Studying The P5 Hall Thruster

    NASA Astrophysics Data System (ADS)

    Gallimore, Alec D.

    2003-05-01

    The Hall thruster is an advanced spacecraft propulsion system that uses electrical power provided by the spacecraft to generate thrust by ionizing and accelerating ions to high velocities. While Hall thrusters have been tested in laboratories for nearly forty years and first flew in space some thirty years ago, little is known about the plasma within these devices. This lack of knowledge has led to the expensive trial-and-error approach practiced in Hall thruster development over the years. The difficulty in collecting interior plasma data stems from the intense heat flux a probe receives. While optical measurements can give some information about the plasma, probes provide data about the plasma that are not accessible with optical approaches. Discharge channel plasma data are vital for extending our understanding of Hall thruster physical processes, for validating thruster models, and for developing advanced, next-generation engines for high ΔV missions. The paper summarizes the results of research aimed at using probes to characterize the internal plasma structure of a laboratory Hall thruster developed specifically for this purpose. Internal plasma parameter measurements were accomplished by using the unique High-speed Axial Reciprocating Probe (HARP) system, which enabled, for the first time, the insertion and removal of probes from the Hall thruster discharge channel while minimizing perturbation to thruster operation. The system was used with an emissive probe to map plasma potential, and a double Langmuir probe to map electron temperature and ion number density. Thruster perturbation, determined by monitoring discharge current, was less than 10% for the majority of measurements.