WorldWideScience

Sample records for cell systems utilizacion

  1. The Usage of Biogas in Fuel Cell Systems; Utilizacion de Biogas en Pilas de Combustible

    Energy Technology Data Exchange (ETDEWEB)

    Perez Martinez, M.; Cuesta Santianes, M. J.; Nunez Crespi, S.; Cabrera Jimenez, J. A.

    2008-08-06

    The usage of biogas in fuel cell systems is nowadays considered as a promising alternative for energy production worldwide as it involves the use of a valuable residual biomass resource that could enable the obtention of combined heat, cold and power generation very efficiently, while additionally avoiding greenhouse gas emissions to the atmosphere. Both development lines (biogas and fuel cells) and their associated technologies are receiving a great support from the different states, pioneer countries being Japan and U.S.A. The objective of this study is to make a detail analysis of the state of the art of biogas-powered fuel cell systems worldwide. Most representative players in the field are identified through the search of the scientific publications, projects and patent documents in which they are involved. (Author) 18 refs.

  2. Feasibility analysis of field bus utilization for local control of electric systems; Analisis de factibilidad de utilizacion de fieldbuses para control local de sistemas electricos

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Fabiana; Feldgen, Maria; Clua, Osvaldo [Buenos Aires Univ., Buenos Aires (Argentina). Faculdad de Ingenieria

    2001-07-01

    For accomplish with local electric systems control is necessary to command and supervise separated equipment for various hundred meters. The traditional solution consists in communication between equipment with a control station central supervision, through a cabled network. Important advantages are obtained by changing to a solution where control are performed in a distributed way and using a local normalized network known as field bus. This paper resumes the main characteristics of these buses. Some conclusions are obtained related to the application of these type of protocols for the substation control and criteria are established for the selection among various available technologies.

  3. Use of efficient technologies in the lighting system for new constructions in hotels; Utilizacion de tecnologias eficientes en el sistema de iluminacion para nuevas construcciones en hoteles

    Energy Technology Data Exchange (ETDEWEB)

    Duran Ramirez, Ricardo [Fideicomiso para el Ahorro de la Energia Electrica (Mexico)

    2005-01-15

    The Fideicomiso para el Ahorro de la Energia Electrica (FIDE) jointly worked with two hotels in construction modifying the original projects of the lighting system to obtain a suitable selection of lamps and lighting control subsystems that would render a saving of 67.5% and 71.0% with respect to the lighting systems originally considered. The project also financed the investment with recovery periods between 1.6 and 2.6 years. It is presented the equivalence between the characteristics of the different types of feasible lamps. [Spanish] El Fideicomiso para el Ahorro de la Energia Electrica (FIDE) trabajo conjuntamente con dos hoteles en construccion modificando los proyectos originales del sistema de iluminacion para lograr una adecuada seleccion de lamparas y subsistemas de control de iluminacion que redituaron en un ahorro del 67.5 y 71.0 % respecto a los sistemas de iluminacion originalmente considerados, al tiempo que financio la inversion con periodos de recuperacion entre 1.6 y 2.6 anos. Se expone una equivalencia entre las caracteristicas de los distintos tipos de lamparas factibles.

  4. Use of a matrix of diodes for the quality control of a collimation multi-leafs system; Utilizacion de un matriz de diodos para el control de calidad de un sistema de colimacion multilaminas

    Energy Technology Data Exchange (ETDEWEB)

    Bejar Navarro, M. J.; Prieto Moran, D.; Sanchez Noriega, K.; Rodriguez Meijide, P.; Esteve Sanchez, S.; Colmenares Fernandez, R.; Capuz Suarez, B.; Ordonez Marquez, J.; Moris Pablos, R.

    2013-07-01

    This study aims to show the first results of the application of the Radiation Defined Reference Line method in our system collimation multi-leafs and verify the effectiveness of this method to align between the leafs of a bed. (Author)

  5. Proposal for the utilization of neural networks for the forecast of the electric power demand in a distribution system; Propuesta de utilizacion de las redes neuronales para la prediccion de la demanda electrica en un sistema de distribucion

    Energy Technology Data Exchange (ETDEWEB)

    Prado, Pedro O.; Aguero, Carlos A.; Ferreyra, Ruben; Passoni, Lucia Isabel; Clara, Fernando [Universidad Nacional de Mar del Plata, Buenos Aires (Argentina). Facultad de Ingenieria

    1997-12-31

    In this work, the first advances of the investigation project are presented that is developed in the University. The main objective of this project is the recognition of patterns and the definition of models of prediction of the energy demand through the neural networks. Achieved these technical indicators will be possible to analyze, in more complete form, the evolution of a system of electric of distribution. The neural networks is technical not parametric that have demonstrated their aptitude so much in the recognition of patterns as in the recognition of patterns as in the prediction of parameters, in diverse areas. At the moment its use in the field of the energy planning, is still a beginner topic. (author) 12 refs., 5 figs.;poprado at fi.mdp.edu.ar; lpassoni at fi.mdp.edu.ar

  6. Las utilizaciones de los esquistos carboníferos

    Directory of Open Access Journals (Sweden)

    Vié, G.

    1976-10-01

    Full Text Available The quarry waste resulting from mining is shale that piles up in such quantities that they get to change the landscape of the region. There is no logic in wasting such great amounts of material and this is the reason why studies have been carried out to get to know to what extent this material could be used in the construction industry. Thus, the experiments and works carried out in the coal mines in northern France have demonstrated that under certain conditions it was possible to take advantage of the shale, taken as raw material with granulated aggregates as end result, which can be used in concrete and brick manufacturing and in road works. The present article studies the procedures and systems for obtaining these granulated aggregates, as well as their field of use.Los escombros resultantes de los trabajos mineros son esquistos residuales, que se amontonan en volúmenes tan considerables que llegan a modificar el paisaje de la región. No era lógico desaprovechar tal cantidad de material, por lo cual se ha llevado a cabo toda una serie de estudios para buscarles un aprovechamiento en la construcción. Así, los experimentos y trabajos realizados en las explotaciones carboníferas del norte de Francia han demostrado que era posible, bajo determinadas condiciones, sacar partido de los esquistos, tomados como materia prima sin valor, obteniendo áridos granulares que se pueden emplear para la fabricación de hormigones y ladrillos, y en trabajos de carreteras. En el presente artículo se estudian los procedimientos y sistemas para la obtención de estos áridos granulares, así como sus campos de aplicación.

  7. Recommendations for the use of high efficiency motors; Recomendaciones para la utilizacion de motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Buitron Sanchez, Horacio [Comision Federal de Electricidad, Mexico, D. F. (Mexico)

    1993-12-31

    In this paper the most important characteristics of the high efficiency motors are examined and the use of these motors as an alternative for the saving and efficient use of the electrical energy is proposed. The operating cost is analyzed in relation with similar standard motors and several suggestions that can help to justify its application are given. [Espanol] En este trabajo se examinan las caracteristicas relevantes de los motores de alta eficiencia y se plantea su utilizacion como alternativa para el ahorro y uso eficiente de la energia electrica. Se analiza su costo de operacion, en relacion con motores estandar similares y se dan varias sugerencias que pueden ayudar a justificar su aplicacion.

  8. Solar cell concentrating system

    International Nuclear Information System (INIS)

    This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

  9. Cell Maintenance Systems

    Science.gov (United States)

    Morrison, D. R.

    1985-01-01

    Living human cells require attachment to a suitable surface and special culture conditions in order to grow. These requirements are modified and amplified when cells are taken into a weightless environment. Special handling and maintenance systems are required for routine laboratory procedures conducted in the Orbiter and in the Spacelab. Methods were developed to maintain cells in special incubators designed for the Orbiter middeck, however, electrophoresis and other experiments require cells to be harvested off of the culture substrate before they can be processed or used. The cell transport assembly (CTA) was flown on STS-8, and results show that improvements are required to maintain adequate numbers of cells in this device longer than 48 hours. The life sciences middeck centrifuge probably can be used, but modifications will be required to transfer cells from the CTA and keep the cells sterile. Automated systems such as the Skylab SO-15 flight hardware and crew operated systems are being evaluated for use on the Space Shuttle, Spacelab, and Space Station research modules.

  10. Fuel cell systems

    International Nuclear Information System (INIS)

    Fuel cell systems are an entirely different approach to the production of electricity than traditional technologies. They are similar to the batteries in that both produce direct current through electrochemical process. There are six types of fuel cells each with a different type of electrolyte, but they all share certain important characteristics: high electrical efficiency, low environmental impact and fuel flexibility. Fuel cells serve a variety of applications: stationary power plants, transport vehicles and portable power. That is why world wide efforts are addressed to improvement of this technology. (Original)

  11. Fuel cell based hybrid systems

    OpenAIRE

    Davat, B.; Astier, S.; Bethoux, O.; CANDUSSO,D; Coquery, G.; DE-BERNARDINIS, A; DRUART, F; Francois, M; GARCIA ARREGUI, F; Harel, F.

    2009-01-01

    This paper presents different works which are currently developed in the field of fuel cell hybrid systems indifferent public laboratories in France. These works are presented in three sections corresponding to: 1. Hybrid fuel cell/battery or supercapacitor power sources; 2. Fuel cell multistack power sources; 3. Fuel cell in hybrid power systems for distributed generation. The presented works combine simulation and experimental results.

  12. Systems biomechanics of the cell

    CERN Document Server

    Maly, Ivan V

    2013-01-01

    Systems Biomechanics of the Cell attempts to outline systems biomechanics of the cell as an emergent and promising discipline. The new field owes conceptually to cell mechanics, organism-level systems biomechanics, and biology of biochemical systems. Its distinct methodology is to elucidate the structure and behavior of the cell by analyzing the unintuitive collective effects of elementary physical forces that interact within the heritable cellular framework. The problematics amenable to this approach includes the variety of cellular activities that involve the form and movement of the cell body and boundary (nucleus, centrosome, microtubules, cortex, and membrane). Among the elementary system effects in the biomechanics of the cell, instability of symmetry, emergent irreversibility, and multiperiodic dissipative motion can be noted. Research results from recent journal articles are placed in this unifying framework. It is suggested that the emergent discipline has the potential to expand the spectrum of ques...

  13. Construction of an electrolytic photocell fuel cell system used to energize a cellular telephone; Construccion de un sistema fotocelda-electrolizador-celda de combustible, utilizado para energizar un telefono celular

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes Quezada, Eduardo; Rodriguez-Castellanos, A.; Solorza Feria, O. [CINVESTAV-IPN, Mexico, D.F. (Mexico)]. E-mail: edfq_1986@hotmail.com

    2009-09-15

    An increase in the worldwide population (roughly 6.3 billion people) has brought about a considerable increase in the demand for energy in order to meet national energy and development needs. Oil and carbon are currently the fuels that are most widely used to generate energy. Nevertheless, their extraction and transport, in addition to their combustion, produce residual pollutants, such as carbon bioxide which is released into the atmosphere and contributes to a large amount of the planet's global warming. An alternative to electric energy generation is the use of polymeric membrane fuel cells (PEMFC), which enable the use of alternative fuels such as hydrogen. This work presents the start-up of a system consisting of a photovoltage cell, an electrolyzer and a PEMFC. The photovoltage cell transforms the solar energy into electric energy which electrolyzes the water to provide hydrogen (fuel) and oxygen (combustion). An electrolyzer was designed and built and was characterized with polarization tests. The gases obtained from the electrolyzer are fed to the fuel cell designed and built in the laboratory. To apply this work, the energy produced in the fuel cell is fed to a low-power device such as the electrical charge of a mobile phone. The integration of electrochemical devices will completely revolutionize today's energy sources, which are based on oil derivatives. These integrated systems are efficient for producing electric energy without emitting gas pollutants. [Spanish] Con el crecimiento de la poblacion mundial, (cercana a 6.3 miles de millones de habitantes en el mundo), se incrementa considerablemente la demanda de energia para cubrir las necesidades energeticas propias y del desarrollo de un pais. El petroleo y el carbon son los combustibles mas empleados en la actualidad para la generacion de energia. Sin embargo, su extraccion y transporte ademas de su combustion traen como consecuencia la produccion de residuos contaminantes, como el bioxido

  14. Fuel cell system with interconnect

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhien; Goettler, Richard; Delaforce, Philip Mark

    2016-03-08

    The present invention includes a fuel cell system having an interconnect that reduces or eliminates diffusion (leakage) of fuel and oxidant by providing an increased densification, by forming the interconnect as a ceramic/metal composite.

  15. Unitized regenerative fuel cell system

    Science.gov (United States)

    Burke, Kenneth A. (Inventor)

    2008-01-01

    A Unitized Regenerative Fuel Cell system uses heat pipes to convey waste heat from the fuel cell stack to the reactant storage tanks. The storage tanks act as heat sinks/sources and as passive radiators of the waste heat from the fuel cell stack. During charge up, i.e., the electrolytic process, gases are conveyed to the reactant storage tanks by way of tubes that include dryers. Reactant gases moving through the dryers give up energy to the cold tanks, causing water vapor in with the gases to condense and freeze on the internal surfaces of the dryer. During operation in its fuel cell mode, the heat pipes convey waste heat from the fuel cell stack to the respective reactant storage tanks, thereby heating them such that the reactant gases, as they pass though the respective dryers on their way to the fuel cell stacks retrieve the water previously removed.

  16. High density cell culture system

    Science.gov (United States)

    Spaulding, Glenn F. (Inventor)

    1994-01-01

    An annular culture vessel for growing mammalian cells is constructed in a one piece integral and annular configuration with an open end which is closed by an endcap. The culture vessel is rotatable about a horizontal axis by use of conventional roller systems commonly used in culture laboratories. The end wall of the endcap has tapered access ports to frictionally and sealingly receive the ends of hypodermic syringes. The syringes permit the introduction of fresh nutrient and withdrawal of spent nutrients. The walls are made of conventional polymeric cell culture material and are subjected to neutron bombardment to form minute gas permeable perforations in the walls.

  17. First cell magnet system tests

    International Nuclear Information System (INIS)

    The ISABELLE refrigeration system utilizes compressed liquid helium to supply refrigeration to nearly 1100 superconducting bending and focusing magnets. These magnets steer the proton orbits of the accelerator and are arranged into two interlocking rings. The total heat load that the refrigerator must provide is made up of the heat load of the magnets, magnet leads and vessels and the interconnecting piping to the refrigerator. The design and test results of the magnet system during various operating conditions in use on the ISABELLE prototype, the First Cell, are described

  18. Fuel-cell engine stream conditioning system

    Science.gov (United States)

    DuBose, Ronald Arthur

    2002-01-01

    A stream conditioning system for a fuel cell gas management system or fuel cell engine. The stream conditioning system manages species potential in at least one fuel cell reactant stream. A species transfer device is located in the path of at least one reactant stream of a fuel cell's inlet or outlet, which transfer device conditions that stream to improve the efficiency of the fuel cell. The species transfer device incorporates an exchange media and a sorbent. The fuel cell gas management system can include a cathode loop with the stream conditioning system transferring latent and sensible heat from an exhaust stream to the cathode inlet stream of the fuel cell; an anode humidity retention system for maintaining the total enthalpy of the anode stream exiting the fuel cell related to the total enthalpy of the anode inlet stream; and a cooling water management system having segregated deionized water and cooling water loops interconnected by means of a brazed plate heat exchanger.

  19. Battery Cell Balancing System and Method

    Science.gov (United States)

    Davies, Francis J. (Inventor)

    2014-01-01

    A battery cell balancing system is operable to utilize a relatively small number of transformers interconnected with a battery having a plurality of battery cells to selectively charge the battery cells. Windings of the transformers are simultaneously driven with a plurality of waveforms whereupon selected battery cells or groups of cells are selected and charged. A transformer drive circuit is operable to selectively vary the waveforms to thereby vary a weighted voltage associated with each of the battery cells.

  20. Technological Prospective (Chapter 3 in 'A vision of year 2030 on the use of the renewable energies in Mexico'); Prospectiva tecnologica (Capitulo 3 en 'Una vision al 2030 de la utilizacion de las energias renovables en Mexico')

    Energy Technology Data Exchange (ETDEWEB)

    Mulas del Pozo, Pablo [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico)

    2005-08-15

    In this chapter it is described how the prospective analysis is carried on in: the trash and its transformation into energy that is made through thermal or biological processes; geothermal, where the relation with low and intermediate temperature resources will be differentiated from those of high temperature for electrical power generation; thermo-solar, that is a high temperature system for electrical power generation and low temperature systems for space heating or process heat; photovoltaic, that is the direct conversion of solar radiation into electricity; the wind energy is the advantage of the kinetic energy of the wind; the use of the biomass or its derivatives requires of transformations on the basis of processes of direct combustion; the gasification or pyrolysis to produce, either in direct form or through the production of a synthetic gas, process heat or electricity in facilities and, mini-hydro energy. [Spanish] En este capitulo se describe como es llevado el analisis prospectivo en: la basura y su transformacion en energia que se realiza a traves de procesos termicos o de procesos biologicos; la geotermia donde se distinguira la relacion con los recursos de temperatura baja e intermedia y los de alta temperatura para generacion electrica; la termosolar que es un sistema de alta temperatura para generacion electrica y sistema de baja temperatura para acondicionamiento de espacios o calor de proceso; fotovoltaico que es la conversion directa de la radiacion solar a electricidad; la energia eolica es el aprovechamiento de la energia cinetica del viento; la utilizacion de la biomasa o sus derivados requiere de transformaciones en base a procesos de combustion directa; la gasificacion o pirolisis para producir, o bien en forma directa o a traves de la produccion de un gas sintetico, calor de proceso o electricidad en instalaciones y, la minihidroenergia.

  1. Modular PEM Fuel Cell SCADA & Simulator System

    Directory of Open Access Journals (Sweden)

    Francisca Segura

    2015-09-01

    Full Text Available The paper presents a Supervision, Control, Data Acquisition and Simulation (SCADA & Simulator system that allows for real-time training in the actual operation of a modular PEM fuel cell system. This SCADA & Simulator system consists of a free software tool that operates in real time and simulates real situations like failures and breakdowns in the system. This developed SCADA & Simulator system allows us to properly operate a fuel cell and helps us to understand how fuel cells operate and what devices are needed to configure and run the fuel cells, from the individual stack up to the whole fuel cell system. The SCADA & Simulator system governs a modular system integrated by three PEM fuel cells achieving power rates higher than tens of kilowatts.

  2. La utilizacion de los mapas conceptuales en la ensenanza de biologia y su efecto sobre el dominio del proceso de fotosintesis en los estudiantes universitarios

    Science.gov (United States)

    Gonzalez Rivera, Maria M.

    Se investigo el efecto de los mapas conceptuales sobre el dominio del proceso de fotosintesis en estudiantes universitarios. La investigacion utilizo dos estrategias: mapas conceptuales individuales y mapas conceptuales colaborativos, con el fin de investigar si existen diferencias significativas en el dominio del proceso de fotosintesis. El analisis de los datos incluyo aspectos cualitativos y cuantitativos. Se desprende del estudio que el 80% de los estudiantes describen la utilizacion de los mapas conceptuales como una experiencia beneficiosa. El 70% de los estudiantes expreso que los mapas conceptuales son utiles en el aprendizaje del proceso de fotosintesis y el 61% indico que facilitan la comprension de los conceptos. Los hallazgos mas importantes del analisis cuantitativo indican que los estudiantes que utilizaron los mapas conceptuales mejoraron significativamente su desempeno en la posprueba global. Se utilizo la prueba Mann-Whitney para investigar si existian diferencias significativas en la posprueba y preprueba global, el valor de W = 1945.0, para un valor p de 0.00, lo cual establece diferencias significativas. Para determinar si existian diferencias significativas entre la posprueba y preprueba del grupo individual, se realizo la prueba nuevamente. El valor de W correspondio a 490.5, que es significativo, con un valor p de 0.00. Se concluye que existen diferencias significativas entre la ejecucion de la posprueba y preprueba del grupo individual. Los datos proveen suficiente evidencia para sostener que los estudiantes que utilizaron la estrategia de mapas conceptuales individuales mejoraron el dominio del proceso de fotosintesis significativamente. Se realizo nuevamente la prueba para los resultados de posprueba y preprueba del grupo colaborativo. El valor de W correspondio a 446 con un valor p de 0.00. Se concluyo que existen diferencias significativas entre la ejecucion de la posprueba y preprueba del grupo colaborativo. Finalmente, se efectuo una

  3. System Studies of Fuel Cell Power Plants

    OpenAIRE

    Kivisaari, Timo

    2001-01-01

    This thesis concerns system studies of power plants wheredifferent types of fuel cells accomplish most of the energyconversion. Ever since William Grove observed the fuel cell effect inthe late 1830s fuel cells have been the subject or more or lessintense research and development. Especially in the USA theseactivities intensified during the second part of the 1950s,resulting in the development of the fuel cells used in theApollo-program. Swedish fuel cell activities started in themid-1960s, w...

  4. Steam electrolysis cell system and electrolyzing method

    International Nuclear Information System (INIS)

    The present invention concerns a method effective to the electrolysis of tritium water in a tritium recovering system of a thermonuclear fuel system. Namely, in a steam electrolysis cell system including integrally constituted multistage type cells and independently disposed single stage type cell, steams are supplied from upstream to the multistage type cell. A voltage is applied at such a level that the concentration of the steams in the vicinity of the single stage type cell situated at the downmost stream among the cells is not decreased to 0 to electrolyze steams. Then, not yet decomposed steams are introduced to the single stage cell to complete the electrolysis. The device can be simplified and steams can be electrolyzed efficiently. (N.H.)

  5. Innovative High Temperature Fuel Cell systems

    NARCIS (Netherlands)

    Au, Siu Fai

    2003-01-01

    The world's energy consumption is growing extremely rapidly. Fuel cell systems are of interest by researchers and industry as the more efficient alternative to conventional thermal systems for power generation. The principle of fuel cell conversion does not involve thermal combustion and hence in th

  6. Microfluidic systems for cell lysis

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Ivona; Grym, Jakub; Klepárník, Karel; Foret, František

    2006. [Annual European Conference on Micro&Nanoscale Technologies for the Biosciences /10./. 14.11.2006-16.11.2006, Montreux] R&D Projects: GA AV ČR IAA400310506; GA AV ČR KAN400310651; GA MŠk LC06023; GA ČR GA203/06/1685 Institutional research plan: CEZ:AV0Z40310501 Keywords : cell lysis * yeast cells * microfluidic device Subject RIV: CB - Analytical Chemistry, Separation

  7. Chip based electroanalytical systems for cell analysis

    DEFF Research Database (Denmark)

    Spegel, C.; Heiskanen, A.; Skjolding, L.H.D.;

    2008-01-01

    ' measurements of processes related to living cells, i.e., systems without lysing the cells. The focus is on chip based amperometric and impedimetric cell analysis systems where measurements utilizing solely carbon fiber microelectrodes (CFME) and other nonchip electrode formats, such as CFME for exocytosis......This review with 239 references has as its aim to give the reader an introduction to the kinds of methods used for developing microchip based electrode systems as well as to cover the existing literature on electroanalytical systems where microchips play a crucial role for 'nondestructive...... studies and scanning electrochemical microscopy (SECM) studies of living cells have been omitted. Included is also a discussion about some future and emerging nano tools and considerations that might have an impact on the future of "nondestructive" chip based electroanalysis of living cells....

  8. Lensless imaging system to quantify cell proliferation

    Science.gov (United States)

    Vinjimore Kesavan, S.; Allier, C. P.; Navarro, F.; Mittler, F.; Chalmond, B.; Dinten, J.-M.

    2013-02-01

    Owing to its simplicity, lensless imaging system is adept at continuous monitoring of adherent cells inside the incubator. The setup consists of a CMOS sensor with pixel pitch of 2.2 μm and field of view of 24 mm2, LED with a dominating wavelength of 525 nm, along with a pinhole of 150 μm as the source of illumination. The in-line hologram obtained from cells depends on the degree of cell-substrate adhesion. Drastic difference is observed between the holographic patterns of floating and adherent cells. In addition, the well-established fact of reduction of cell-substrate contact during cell division is observed with our system based on corresponding spontaneous transition in the holographic pattern. Here, we demonstrate that by recognizing this specific holographic pattern, number of cells undergoing mitosis in a cell culture with a population of approximately 5000 cells, can be estimated in real-time. The method is assessed on comparison with Edu-based proliferation assay. The approach is straightforward and it eliminates the use of markers to estimate the proliferation rate of a given cell culture. Unlike most proliferation assays, the cells are not harvested enabling continuous monitoring of cell culture.

  9. Water reactive hydrogen fuel cell power system

    Science.gov (United States)

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-01-21

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  10. Water balance in fuel cells systems

    International Nuclear Information System (INIS)

    Fuel cell systems are attractive for their high efficiency (i.e., electric power generated per weight/volume of fuel,) and lower emissions. These systems are being developed for applications that include transportation (propulsion and auxiliary), remote stationary, and portable. Where these systems use on-board fuel processing of available fuels, the fuel processor requires high-purity water. For utility applications, this water may be available on-site, but for most applications, the process water must be recovered from the fuel cell system exhaust gas. For such applications, it is critically important that the fuel cell system be a net water-producing device. A variety of environmental conditions (e.g., ambient temperature, pressure), fuel cell system design, and operating conditions determine whether the fuel cell system is water-producing or water-consuming. This paper will review and discuss the conditions that determine the net-water balance of a generic fuel cell system and identify some options that will help meet the water needs of the fuel processor

  11. An Automatic Indirect Immunofluorescence Cell Segmentation System

    Directory of Open Access Journals (Sweden)

    Yung-Kuan Chan

    2014-01-01

    Full Text Available Indirect immunofluorescence (IIF with HEp-2 cells has been used for the detection of antinuclear autoantibodies (ANA in systemic autoimmune diseases. The ANA testing allows us to scan a broad range of autoantibody entities and to describe them by distinct fluorescence patterns. Automatic inspection for fluorescence patterns in an IIF image can assist physicians, without relevant experience, in making correct diagnosis. How to segment the cells from an IIF image is essential in developing an automatic inspection system for ANA testing. This paper focuses on the cell detection and segmentation; an efficient method is proposed for automatically detecting the cells with fluorescence pattern in an IIF image. Cell culture is a process in which cells grow under control. Cell counting technology plays an important role in measuring the cell density in a culture tank. Moreover, assessing medium suitability, determining population doubling times, and monitoring cell growth in cultures all require a means of quantifying cell population. The proposed method also can be used to count the cells from an image taken under a fluorescence microscope.

  12. Direct methanol feed fuel cell and system

    Science.gov (United States)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2009-01-01

    Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous. The fuel cell system also comprises a fuel supplying part including a meter which meters an amount of fuel which is used by the fuel cell, and controls the supply of fuel based on said metering.

  13. Regenerative fuel cell systems R and D

    Energy Technology Data Exchange (ETDEWEB)

    Mitlitsky, F.; Myers, B.; Weisberg, A.H. [Lawrence Livermore National Lab., Livermore, CA (United States)

    1998-08-01

    Regenerative fuel cell (RFC) systems produce power and electrolytically regenerate their reactants using stacks of electrochemical cells. Energy storage systems with extremely high specific energy (> 400 Wh/kg) have been designed that use lightweight pressure vessels to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs). Progress is reported on the development, integration, and operation of rechargeable energy storage systems with such high specific energy. Lightweight pressure vessels that enable high specific energies have been designed with performance factors (burst pressure/internal volume/tank weight) > 50 km (2.0 million inches), and a vessel with performance factor of 40 km (1.6 million inches) was fabricated. New generations of both advanced and industry-supplied hydrogen tankage are under development. A primary fuel cell test rig with a single cell (46 cm{sup 2} active area) has been modified and operated reversibly as a URFC (for up to 2010 cycles on a single cell). This URFC uses bifunctional electrodes (oxidation and reduction electrodes reverse roles when switching from charge to discharge, as with a rechargeable battery) and cathode feed electrolysis (water is fed from the hydrogen side of the cell). Recent modifications also enable anode feed electrolysis (water is fed from the oxygen side of the cell). Hydrogen/halogen URFCs, capable of higher round-trip efficiency than hydrogen/oxygen URFCs, have been considered, and will be significantly heavier. Progress is reported on higher performance hydrogen/oxygen URFC operation with reduced catalyst loading.

  14. Mammalian Cell-Based Sensor System

    Science.gov (United States)

    Banerjee, Pratik; Franz, Briana; Bhunia, Arun K.

    Use of living cells or cellular components in biosensors is receiving increased attention and opens a whole new area of functional diagnostics. The term "mammalian cell-based biosensor" is designated to biosensors utilizing mammalian cells as the biorecognition element. Cell-based assays, such as high-throughput screening (HTS) or cytotoxicity testing, have already emerged as dependable and promising approaches to measure the functionality or toxicity of a compound (in case of HTS); or to probe the presence of pathogenic or toxigenic entities in clinical, environmental, or food samples. External stimuli or changes in cellular microenvironment sometimes perturb the "normal" physiological activities of mammalian cells, thus allowing CBBs to screen, monitor, and measure the analyte-induced changes. The advantage of CBBs is that they can report the presence or absence of active components, such as live pathogens or active toxins. In some cases, mammalian cells or plasma membranes are used as electrical capacitors and cell-cell and cell-substrate contact is measured via conductivity or electrical impedance. In addition, cytopathogenicity or cytotoxicity induced by pathogens or toxins resulting in apoptosis or necrosis could be measured via optical devices using fluorescence or luminescence. This chapter focuses mainly on the type and applications of different mammalian cell-based sensor systems.

  15. IBCIS:Intelligent blood cell identification system

    Institute of Scientific and Technical Information of China (English)

    Adnan Khashman

    2008-01-01

    The analysis of blood cells in microscope images can provide useful information concerning the health of patients.There are three major blood cell types,namely,erythrocytes (red),leukocytes (white),and platelets.Manual classification is time consuming and susceptible to error due to the different morphological features of the cells.This paper presents an intelligent system that simulates a human visual inspection and classification of the three blood cell types.The proposed system comprises two phases:The image preprocessing phase where blood cell features are extracted via global pattern averaging,and the neural network arbitration phase where training is the first and then classification is carried out.Experimental results suggest that the proposed method performs well in identifying blood cell types regardless of their irregular shapes,sizes and orientation,thus providing a fast,simple and efficient rotational and scale invariant blood cell identification system which can be used in automating laboratory reporting.

  16. Fuel cell using a hydrogen generation system

    Science.gov (United States)

    Dentinger, Paul M.; Crowell, Jeffrey A. W.

    2010-10-19

    A system is described for storing and generating hydrogen and, in particular, a system for storing and generating hydrogen for use in an H.sub.2/O.sub.2 fuel cell. The hydrogen storage system uses beta particles from a beta particle emitting material to degrade an organic polymer material to release substantially pure hydrogen. In a preferred embodiment of the invention, beta particles from .sup.63Ni are used to release hydrogen from linear polyethylene.

  17. Control and optimization in fuel cell systems

    International Nuclear Information System (INIS)

    Fuel cells are electrochemical energy converters. They convert the chemical energy contained in the fuel into electricity while producing water and heat. Compared to the traditional energy converters, such as batteries and internal combustion engines, fuel cells are marked by high conversion efficiency and very low emissions.This work contains a computer study of optimization and control of fuel cells systems. An analytical study of the fuel (Hydrogen and air) supply system was performed taking into account compressor, cooling and humidification subsystems. In addition, the stack system, which consists of a lot of cells, was analyzed using the experimental equations of Nafion 117 membrane. The model of the whole system was then implemented in MATLAB/Simulink environment. The effect of the cathode pressure and the membrane water content on the polarization curves of the cell was examined. To validate the model, the responses of the model to step changes in the compressor voltage and the current drawn from the stack, were used. More attention was given to the net power which can be provided by the system, taking into account the power wasted by the compressor. (author)

  18. Water injected fuel cell system compressor

    Science.gov (United States)

    Siepierski, James S.; Moore, Barbara S.; Hoch, Martin Monroe

    2001-01-01

    A fuel cell system including a dry compressor for pressurizing air supplied to the cathode side of the fuel cell. An injector sprays a controlled amount of water on to the compressor's rotor(s) to improve the energy efficiency of the compressor. The amount of water sprayed out the rotor(s) is controlled relative to the mass flow rate of air inputted to the compressor.

  19. An Automatic Indirect Immunofluorescence Cell Segmentation System

    OpenAIRE

    2014-01-01

    Indirect immunofluorescence (IIF) with HEp-2 cells has been used for the detection of antinuclear autoantibodies (ANA) in systemic autoimmune diseases. The ANA testing allows us to scan a broad range of autoantibody entities and to describe them by distinct fluorescence patterns. Automatic inspection for fluorescence patterns in an IIF image can assist physicians, without relevant experience, in making correct diagnosis. How to segment the cells from an IIF image is essential in developing an...

  20. Solid oxide fuel cell power system development

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Rick [Delphi Automotive Systems, LLC., Troy, MI (United States); Wall, Mark [Independent Energy Partners Technology, LLC., Parker, CO (United States); Sullivan, Neal [Colorado School of Mines, Golden, CO (United States)

    2015-06-26

    This report summarizes the progress made during this contractual period in achieving the goal of developing the solid oxide fuel cell (SOFC) cell and stack technology to be suitable for use in highly-efficient, economically-competitive, commercially deployed electrical power systems. Progress was made in further understanding cell and stack degradation mechanisms in order to increase stack reliability toward achieving a 4+ year lifetime, in cost reduction developments to meet the SECA stack cost target of $175/kW (in 2007 dollars), and in operating the SOFC technology in a multi-stack system in a real-world environment to understand the requirements for reliably designing and operating a large, stationary power system.

  1. Fuel cell technology for prototype logistic fuel cell mobile systems

    Energy Technology Data Exchange (ETDEWEB)

    Sederquist, R.A.; Garow, J.

    1995-08-01

    Under the aegis of the Advanced Research Project Agency`s family of programs to develop advanced technology for dual use applications, International Fuel Cells Corporation (IFC) is conducting a 39 month program to develop an innovative system concept for DoD Mobile Electric Power (MEP) applications. The concept is to integrate two technologies, the phosphoric acid fuel cell (PAFC) with an auto-thermal reformer (ATR), into an efficient fuel cell power plant of nominally 100-kilowatt rating which operates on logistic fuels (JP-8). The ATR fuel processor is the key to meeting requirements for MEP (including weight, volume, reliability, maintainability, efficiency, and especially operation on logistic fuels); most of the effort is devoted to ATR development. An integrated demonstration test unit culminates the program and displays the benefits of the fuel cell system, relative to the standard 100-kilowatt MEP diesel engine generator set. A successful test provides the basis for proceeding toward deployment. This paper describes the results of the first twelve months of activity during which specific program aims have remained firm.

  2. Cell-based bioassays in microfluidic systems

    Science.gov (United States)

    Itle, Laura J.; Zguris, Jeanna C.; Pishko, Michael V.

    2004-12-01

    The development of cell-based bioassays for high throughput drug screening or the sensing of biotoxins is contingent on the development of whole cell sensors for specific changes in intracellular conditions and the integration of those systems into sample delivery devices. Here we show the feasibility of using a 5-(and-6)-carboxy SNARF-1, acetoxymethyl ester, acetate, a fluorescent dye capable of responding to changes in intracellular pH, as a detection method for the bacterial endotoxin, lipopolysaccharide. We used photolithography to entrap cells with this dye within poly(ethylene) glyocol diacrylate hydrogels in microfluidic channels. After 18 hours of exposure to lipopolysaccharide, we were able to see visible changes in the fluorescent pattern. This work shows the feasibility of using whole cell based biosensors within microfluidic networks to detect cellular changes in response to exogenous agents.

  3. Constructing a High Density Cell Culture System

    Science.gov (United States)

    Spaulding, Glenn F. (Inventor)

    1996-01-01

    An annular culture vessel for growing mammalian cells is constructed in a one piece integral and annular configuration with an open end which is closed by an endcap. The culture vessel is rotatable about a horizontal axis by use of conventional roller systems commonly used in culture laboratories. The end wall of the endcap has tapered access ports to frictionally and sealingly receive the ends of hypodermic syringes. The syringes permit the introduction of fresh nutrient and withdrawal of spent nutrients. The walls are made of conventional polymeric cell culture material and are subjected to neutron bombardment to form minute gas permeable perforations in the walls.

  4. Some future tendencies in the electric power systems; Algunas tendencias futuras en los sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento Uruchurtu, Hector Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1995-12-31

    This document describes the most important tendencies on energy generation transmission and utilization of the electric power systems. The underlining of these tendencies has the purpose of maintaining a constant alert on the possible technological advances that must be covered at medium and long term in the Coordination Analysis of Transmission Systems [Espanol] En el presente documento se describen las tendencias mas importantes sobre generacion, transmision y utilizacion de la energia, en cuanto a los sistemas electricos de potencia. El destacar estas tendencias tiene por objeto una alerta constante sobre los posibles desarrollos tecnologicos que se deben abordar a mediano y largo plazo dentro de la Coordinacion de Analisis de Sistemas de Transmision

  5. Solid Oxide Fuel Cell Systems PVL Line

    Energy Technology Data Exchange (ETDEWEB)

    Susan Shearer - Stark State College; Gregory Rush - Rolls-Royce Fuel Cell Systems

    2012-05-01

    In July 2010, Stark State College (SSC), received Grant DE-EE0003229 from the U.S. Department of Energy (DOE), Golden Field Office, for the development of the electrical and control systems, and mechanical commissioning of a unique 20kW scale high-pressure, high temperature, natural gas fueled Stack Block Test System (SBTS). SSC worked closely with subcontractor, Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) over a 13 month period to successfully complete the project activities. This system will be utilized by RRFCS for pre-commercial technology development and training of SSC student interns. In the longer term, when RRFCS is producing commercial products, SSC will utilize the equipment for workforce training. In addition to DOE Hydrogen, Fuel Cells, and Infrastructure Technologies program funding, RRFCS internal funds, funds from the state of Ohio, and funding from the DOE Solid State Energy Conversion Alliance (SECA) program have been utilized to design, develop and commission this equipment. Construction of the SBTS (mechanical components) was performed under a Grant from the State of Ohio through Ohio's Third Frontier program (Grant TECH 08-053). This Ohio program supported development of a system that uses natural gas as a fuel. Funding was provided under the Department of Energy (DOE) Solid-state Energy Conversion Alliance (SECA) program for modifications required to test on coal synthesis gas. The subject DOE program provided funding for the electrical build, control system development and mechanical commissioning. Performance testing, which includes electrical commissioning, was subsequently performed under the DOE SECA program. Rolls-Royce Fuel Cell Systems is developing a megawatt-scale solid oxide fuel cell (SOFC) stationary power generation system. This system, based on RRFCS proprietary technology, is fueled with natural gas, and operates at elevated pressure. A critical success factor for development of the full scale system is the capability

  6. Phase Space Cell in Nonextensive Classical Systems

    CERN Document Server

    Quarati, F

    2003-01-01

    We calculate the phase space volume $Omega$ occupied by a nonextensive system of $N$ classical particles described by an equilibrium (or steady-state, or long-term stationary state of a nonequilibrium system) distribution function, which slightly deviates from Maxwell-Boltzmann (MB) distribution in the high energy tail. We explicitly require that the number of accessible microstates does not change respect to the extensive MB case. We also derive, within a classical scheme, an analytical expression of the elementary cell that can be seen as a macrocell, different from the third power of Planck constant. Thermodynamic quantities like entropy, chemical potential and free energy of a classical ideal gas, depending on elementary cell, are evaluated. Considering the fractional deviation from MB distribution we can deduce a physical meaning of the nonextensive parameter $q$ of the Tsallis nonextensive thermostatistics in terms of particle correlation functions (valid at least in the case, discussed in this work, of...

  7. Systemic adjuvant therapies in renal cell carcinoma

    OpenAIRE

    Sebastiano Buti; Melissa Bersanelli; Maddalena Donini; Andrea Ardizzoni

    2012-01-01

    Renal cell carcinoma (RCC) is one of the ten most frequent solid tumors worldwide. Recent innovations in the treatment of metastatic disease have led to new therapeutic approaches being investigated in the adjuvant setting. Observation is the only current standard of care after radical nephrectomy, although there is evidence of efficacy of adjuvant use of vaccine among all the strategies used. This article aims to collect published experiences with systemic adjuvant approaches in RCC and to d...

  8. Sensor Development for PEM Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Steve Magee; Richard Gehman

    2005-07-12

    This document reports on the work done by Honeywell Sensing and Control to investigate the feasibility of modifying low cost Commercial Sensors for use inside a PEM Fuel Cell environment. Both stationary and automotive systems were considered. The target environment is hotter (100 C) than the typical commercial sensor maximum of 70 C. It is also far more humid (100% RH condensing) than the more typical 95% RH non-condensing at 40 C (4% RH maximum at 100 C). The work focused on four types of sensors, Temperature, Pressure, Air Flow and Relative Humidity. Initial design goals were established using a market research technique called Market Driven Product Definition (MDPD). A series of interviews were conducted with various users and system designers in their facilities. The interviewing team was trained in data taking and analysis per the MDPD process. The final result was a prioritized and weighted list of both requirements and desires for each sensor. Work proceeded on concept development for the 4 types of sensors. At the same time, users were developing the actual fuel cell systems and gaining knowledge and experience in the use of sensors and controls systems. This resulted in changes to requirements and desires that were not anticipated during the MDPD process. The concepts developed met all the predicted requirements. At the completion of concept development for the Pressure Sensor, it was determined that the Fuel Cell developers were happy with off-the-shelf automotive pressure sensors. Thus, there was no incentive to bring a new Fuel Cell Specific Pressure Sensor into production. Work was therefore suspended. After the experience with the Pressure Sensor, the requirements for a Temperature Sensor were reviewed and a similar situation applied. Commercially available temperature sensors were adequate and cost effective and so the program was not continued from the Concept into the Design Phase.

  9. System for adding sulfur to a fuel cell stack system for improved fuel cell stability

    Science.gov (United States)

    Mukerjee, Subhasish; Haltiner, Jr., Karl J; Weissman, Jeffrey G

    2013-08-13

    A system for adding sulfur to a reformate stream feeding a fuel cell stack, having a sulfur source for providing sulfur to the reformate stream and a metering device in fluid connection with the sulfur source and the reformate stream. The metering device injects sulfur from the sulfur source to the reformate stream at a predetermined rate, thereby providing a conditioned reformate stream to the fuel cell stack. The system provides a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.

  10. Translation in cell-free systems

    International Nuclear Information System (INIS)

    The simplest, unambiguous identification of a particular mRNA is the identification of its protein product. This can be established by translation of the mRNA of interest in a cell-free protein-synthesizing system. Messenger RNA protein product identification is important in the isolation of a particular mRNA species for cDNA cloning and in the identification of positive cDNA clones. The two high-activity translation systems in common use are those prepared from rabbit reticulocytes and from wheat germ. Both systems are easy to prepare, and both are available commercially. Each has advantages and disadvantages over the other and a choice between the two will depend on the type of mRNAs to be translated, the prejudices of experience, and availability. The main disadvantage of the reticulocyte system is that it requires removal of endogenous mRNA. However, this is a relatively simple procedure. The wheat germ system does not require removal of endogenous mRNA and may translate weakly initiating mRNAs more efficiently. However, ionic optima for translation in the wheat germ system are more sensitive to the nature and concentration of mRNA and may need to be determined for each template. The biggest problem with the use of the wheat germ system is its tendency to produce incomplete translation products due to premature termination

  11. Use of nuclear fusion systems for spent nuclear fuel degradation;Utilizacion de sistemas de fusion nuclear para degradacion de combustible nuclear gastado

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, M.; Ramos, G. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Queretaro, Cerro Blanco 141, Colinas del Cimatario, 76090 Queretaro (Mexico); Herrera V, J. J. E., E-mail: mnieto@ipn.m [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico, D. F. (Mexico)

    2009-10-15

    One of the severe problems of the nuclear industry that should be resolved to facilitate its acceptance like viable energy alternative is of the wastes. In spite of having alternative of fuel reprocessing, many of them have been abandoned by economic or security reasons. In the present work, the alternative is described for using reactors of nuclear fusion as sources of fast neutrons with two important applications in mind: the plutonium burning and the transmutation of the elements that contribute in way more important to their radioactivity, mainly the smaller actinides and the fission products of long half life. (Author)

  12. Fuel processor for fuel cell power system

    Science.gov (United States)

    Vanderborgh, Nicholas E.; Springer, Thomas E.; Huff, James R.

    1987-01-01

    A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

  13. Optimization of Fuel Cell System Operating Conditions for Fuel Cell Vehicles

    OpenAIRE

    Zhao, Hengbing; Burke, Andy

    2008-01-01

    Proton Exchange Membrane fuel cell (PEMFC) technology for use in fuel cell vehicles and other applications has been intensively developed in recent decades. Besides the fuel cell stack, air and fuel control and thermal and water management are major challenges in the development of the fuel cell for vehicle applications. The air supply system can have a major impact on overall system efficiency. In this paper a fuel cell system model for optimizing system operating conditions was developed wh...

  14. Dynamic cell culture system (7-IML-1)

    Science.gov (United States)

    Cogoli, Augusto

    1992-01-01

    This experiment is one of the Biorack experiments being flown on the International Microgravity Laboratory 1 (MIL-1) mission as part of an investigation studying cell proliferation and performance in space. One of the objectives of this investigation is to assess the potential benefits of bioprocessing in space with the ultimate goal of developing a bioreactor for continuous cell cultures in space. This experiment will test the operation of an automated culture chamber that was designed for use in a Bioreactor in space. The device to be tested is called the Dynamic Cell Culture System (DCCS). It is a simple device in which media are renewed or chemicals are injected automatically, by means of osmotic pumps. This experiment uses four Type I/O experiment containers. One DCCS unit, which contains a culture chamber with renewal of medium and a second chamber without a medium supply fits in each container. Two DCCS units are maintained under zero gravity conditions during the on-orbit period. The other two units are maintained under 1 gh conditions in a 1 g centrifuge. The schedule for incubator transfer is given.

  15. Phase Space Cell in Nonextensive Classical Systems

    Directory of Open Access Journals (Sweden)

    Piero Quarati

    2003-06-01

    Full Text Available Abstract: We calculate the phase space volume Ω occupied by a nonextensive system of N classical particles described by an equilibrium (or steady-state, or long-term stationary state of a nonequilibrium system distribution function, which slightly deviates from Maxwell-Boltzmann (MB distribution in the high energy tail. We explicitly require that the number of accessible microstates does not change respect to the extensive MB case. We also derive, within a classical scheme, an analytical expression of the elementary cell that can be seen as a macrocell, different from the third power of Planck constant. Thermodynamic quantities like entropy, chemical potential and free energy of a classical ideal gas, depending on elementary cell, are evaluated. Considering the fractional deviation from MB distribution we can deduce a physical meaning of the nonextensive parameter q of the Tsallis nonextensive thermostatistics in terms of particle correlation functions (valid at least in the case, discussed in this work, of small deviations from MB standard case.

  16. Status of commercial fuel cell powerplant system development

    Science.gov (United States)

    Warshay, Marvin

    The primary focus is on the development of commercial Phosphoric Acid Fuel Cell (PAFC) powerplant systems because the PAFC, which has undergone extensive development, is currently the closest fuel cell system to commercialization. Shorter discussions are included on the high temperature fuel cell systems which are not as mature in their development, such as the Molten Carbonate Fuel Cell (MCFC) and the Solid Oxide Fuel Cell (SOFC). The alkaline and the Solid Polymer Electrolyte (SPE) fuel cell systems, are also included, but their discussions are limited to their prospects for commercial development. Currently, although the alkaline fuel cell continues to be used for important space applications there are no commercial development programs of significant size in the USA and only small efforts outside. The market place for fuel cells and the status of fuel cell programs in the USA receive extensive treatment. The fuel cell efforts outside the USA, especially the large Japanese programs, are also discussed.

  17. Systems Biology for Organotypic Cell Cultures

    Energy Technology Data Exchange (ETDEWEB)

    Grego, Sonia [RTI International, Research Triangle Park, NC (United States); Dougherty, Edward R. [Texas A & M Univ., College Station, TX (United States); Alexander, Francis J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Auerbach, Scott S. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Berridge, Brian R. [GlaxoSmithKline, Research Triangle Park, NC (United States); Bittner, Michael L. [Translational Genomics Research Inst., Phoenix, AZ (United States); Casey, Warren [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Cooley, Philip C. [RTI International, Research Triangle Park, NC (United States); Dash, Ajit [HemoShear Therapeutics, Charlottesville, VA (United States); Ferguson, Stephen S. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Fennell, Timothy R. [RTI International, Research Triangle Park, NC (United States); Hawkins, Brian T. [RTI International, Research Triangle Park, NC (United States); Hickey, Anthony J. [RTI International, Research Triangle Park, NC (United States); Kleensang, Andre [Johns Hopkins Univ., Baltimore, MD (United States). Center for Alternatives to Animal Testing; Liebman, Michael N. [IPQ Analytics, Kennett Square, PA (United States); Martin, Florian [Phillip Morris International, Neuchatel (Switzerland); Maull, Elizabeth A. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Paragas, Jason [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Qiao, Guilin [Defense Threat Reduction Agency, Ft. Belvoir, VA (United States); Ramaiahgari, Sreenivasa [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Sumner, Susan J. [RTI International, Research Triangle Park, NC (United States); Yoon, Miyoung [The Hamner Inst. for Health Sciences, Research Triangle Park, NC (United States); ScitoVation, Research Triangle Park, NC (United States)

    2016-08-04

    Translating in vitro biological data into actionable information related to human health holds the potential to improve disease treatment and risk assessment of chemical exposures. While genomics has identified regulatory pathways at the cellular level, translation to the organism level requires a multiscale approach accounting for intra-cellular regulation, inter-cellular interaction, and tissue/organ-level effects. Tissue-level effects can now be probed in vitro thanks to recently developed systems of three-dimensional (3D), multicellular, “organotypic” cell cultures, which mimic functional responses of living tissue. However, there remains a knowledge gap regarding interactions across different biological scales, complicating accurate prediction of health outcomes from molecular/genomic data and tissue responses. Systems biology aims at mathematical modeling of complex, non-linear biological systems. We propose to apply a systems biology approach to achieve a computational representation of tissue-level physiological responses by integrating empirical data derived from organotypic culture systems with computational models of intracellular pathways to better predict human responses. Successful implementation of this integrated approach will provide a powerful tool for faster, more accurate and cost-effective screening of potential toxicants and therapeutics. On September 11, 2015, an interdisciplinary group of scientists, engineers, and clinicians gathered for a workshop in Research Triangle Park, North Carolina, to discuss this ambitious goal. Participants represented laboratory-based and computational modeling approaches to pharmacology and toxicology, as well as the pharmaceutical industry, government, non-profits, and academia. Discussions focused on identifying critical system perturbations to model, the computational tools required, and the experimental approaches best suited to generating key data. This consensus report summarizes the discussions held.

  18. System-level modeling and simulation of the cell culture microfluidic biochip ProCell

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan;

    2010-01-01

    -defined micro-channels using valves and pumps. We present an approach to the system-level modeling and simulation of a cell culture microfluidic biochip called ProCell, Programmable Cell Culture Chip. ProCell contains a cell culture chamber, which is envisioned to run 256 simultaneous experiments (viewed as a...

  19. Drug delivery system and breast cancer cells

    Science.gov (United States)

    Colone, Marisa; Kaliappan, Subramanian; Calcabrini, Annarica; Tortora, Mariarosaria; Cavalieri, Francesca; Stringaro, Annarita

    2016-06-01

    Recently, nanomedicine has received increasing attention for its ability to improve the efficacy of cancer therapeutics. Nanosized polymer therapeutic agents offer the advantage of prolonged circulation in the blood stream, targeting to specific sites, improved efficacy and reduced side effects. In this way, local, controlled delivery of the drug will be achieved with the advantage of a high concentration of drug release at the target site while keeping the systemic concentration of the drug low, thus reducing side effects due to bioaccumulation. Various drug delivery systems such as nanoparticles, liposomes, microparticles and implants have been demonstrated to significantly enhance the preventive/therapeutic efficacy of many drugs by increasing their bioavailability and targetability. As these carriers significantly increase the therapeutic effect of drugs, their administration would become less cost effective in the near future. The purpose of our research work is to develop a delivery system for breast cancer cells using a microvector of drugs. These results highlight the potential uses of these responsive platforms suited for biomedical and pharmaceutical applications. At the request of all authors of the paper an updated version was published on 12 July 2016. The manuscript was prepared and submitted without Dr. Francesca Cavalieri's contribution and her name was added without her consent. Her name has been removed in the updated and re-published article.

  20. Waveform control of fuel-cell inverter systems

    OpenAIRE

    Zhu, GR; Wang, KW; Tse, CK; Tan, SC

    2012-01-01

    Fuel-cell power systems comprising single-phase DC/AC inverters draw low-frequency AC ripple currents at twice the output frequency from the fuel cell. Such a 100/120 Hz ripple current may create instability in the fuel cell system, lowers its efficiency, and shortens the lifetime of fuel cell stack. This paper1 presents a waveform control method that can mitigate such a low-frequency ripple current from being drawn from the fuel cell while the fuel-cell system delivers AC power to the load t...

  1. Simplified Load-Following Control for a Fuel Cell System

    Science.gov (United States)

    Vasquez, Arturo

    2010-01-01

    A simplified load-following control scheme has been proposed for a fuel cell power system. The scheme could be used to control devices that are important parts of a fuel cell system but are sometimes characterized as parasitic because they consume some of the power generated by the fuel cells.

  2. Systemic adjuvant therapies in renal cell carcinoma.

    Science.gov (United States)

    Buti, Sebastiano; Bersanelli, Melissa; Donini, Maddalena; Ardizzoni, Andrea

    2012-10-01

    Renal cell carcinoma (RCC) is one of the ten most frequent solid tumors worldwide. Recent innovations in the treatment of metastatic disease have led to new therapeutic approaches being investigated in the adjuvant setting. Observation is the only current standard of care after radical nephrectomy, although there is evidence of efficacy of adjuvant use of vaccine among all the strategies used. This article aims to collect published experiences with systemic adjuvant approaches in RCC and to describe the results of past and ongoing phase III clinical trials in this field. We explored all the systemic treatments, including chemotherapy, immunotherapy and targeted drugs while alternative approaches have also been described. Appropriate selection of patients who would benefit from adjuvant therapies remains a crucial dilemma. Although the international guidelines do not actually recommend any adjuvant treatment after radical surgery for RCC, no conclusions have yet been drawn pending the results of the promising ongoing clinical trials with the target therapies. The significant changes that these new drugs have made on advanced disease outcome could represent the key to innovation in terms of preventing recurrence, delaying relapse and prolonging survival after radical surgery for RCC. PMID:25992216

  3. Systemic adjuvant therapies in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Sebastiano Buti

    2012-10-01

    Full Text Available Renal cell carcinoma (RCC is one of the ten most frequent solid tumors worldwide. Recent innovations in the treatment of metastatic disease have led to new therapeutic approaches being investigated in the adjuvant setting. Observation is the only current standard of care after radical nephrectomy, although there is evidence of efficacy of adjuvant use of vaccine among all the strategies used. This article aims to collect published experiences with systemic adjuvant approaches in RCC and to describe the results of past and ongoing phase III clinical trials in this field. We explored all the systemic treatments, including chemotherapy, immunotherapy and targeted drugs while alternative approaches have also been described. Appropriate selection of patients who would benefit from adjuvant therapies remains a crucial dilemma. Although the international guidelines do not actually recommend any adjuvant treatment after radical surgery for RCC, no conclusions have yet been drawn pending the results of the promising ongoing clinical trials with the target therapies. The significant changes that these new drugs have made on advanced disease outcome could represent the key to innovation in terms of preventing recurrence, delaying relapse and prolonging survival after radical surgery for RCC.

  4. Stem cell biology meets systems biology

    OpenAIRE

    Roeder, I.; Radtke, F.

    2009-01-01

    Stem cells and their descendents are the building blocks of life. How stem cell populations guarantee their maintenance and/or self-renewal, and how individual stem cells decide to transit from one cell stage to another to generate different cell types are long-standing and fascinating questions in the field. Here, we review the discussions that took place at a recent EMBO conference in Cambridge, UK, in which these questions were placed in the context of the latest advances in stem cell biol...

  5. Comparison of defined culture systems for feeder cell free propagation of human embryonic stem cells

    OpenAIRE

    Akopian, Veronika; Andrews, Peter W.; Beil, Stephen; Benvenisty, Nissim; Brehm, Jennifer; Christie, Megan; Ford, Angela; Fox, Victoria; Gokhale, Paul J; Healy, Lyn; Holm, Frida; Hovatta, Outi; Knowles, Barbara B; Ludwig, Tenneille E; Ronald D G McKay

    2010-01-01

    There are many reports of defined culture systems for the propagation of human embryonic stem cells in the absence of feeder cell support, but no previous study has undertaken a multi-laboratory comparison of these diverse methodologies. In this study, five separate laboratories, each with experience in human embryonic stem cell culture, used a panel of ten embryonic stem cell lines (including WA09 as an index cell line common to all laboratories) to assess eight cell culture methods, with pr...

  6. Physics of cell adhesion: some lessons from cell-mimetic systems

    OpenAIRE

    Sackmann, Erich; Smith, Ana-Sunčana

    2014-01-01

    Cell adhesion is a paradigm of the ubiquitous interplay of cell signalling, modulation of material properties and biological functions of cells. It is controlled by competition of short range attractive forces, medium range repellant forces and the elastic stresses associated with local and global deformation of the composite cell envelopes. We review the basic physical rules governing the physics of cell adhesion learned by studying cell-mimetic systems and demonstrate the importance of thes...

  7. Aging and the Dendritic Cell System: Implications for Cancer

    OpenAIRE

    Shurin, Michael R.; Shurin, Galina V.; Chatta, Gurkamal S.

    2007-01-01

    The immune system shows a decline in responsiveness to antigens both with aging, as well as in the presence of tumors. The malfunction of the immune system with age can be attributed to developmental and functional alterations in several cell populations. Previous studies have shown defects in humoral responses and abnormalities in T cell function in aged individuals, but have not distinguished between abnormalities in antigen presentation and intrinsic T cell or B cell defects in aged indivi...

  8. System-level design of bacterial cell cycle control

    OpenAIRE

    McAdams, Harley H.; Shapiro, Lucy

    2009-01-01

    Understanding of the cell cycle control logic in Caulobacter has progressed to the point where we now have an integrated view of the operation of an entire bacterial cell cycle system functioning as a state machine. Oscillating levels of a few temporally-controlled master regulator proteins in a cyclical circuit drive cell cycle progression. To a striking degree, the cell cycle regulation is a whole cell phenomenon. Phospho-signaling proteins and proteases dynamically deployed to specific loc...

  9. T cells and the humoral immune system

    NARCIS (Netherlands)

    W.B. van Muiswinkel (Willem)

    1975-01-01

    textabstractLymphoid cells and macrophages play an important role in the development and rnaintance of humoral and cellular immunity in mammals. The lymphoid cells in the peripheral lymphoid organs are divided into two major classes: (1) thymus-derived lymphocytes or T cells and (2) bursa-equivalent

  10. Cell fate control in the developing central nervous system

    International Nuclear Information System (INIS)

    The principal neural cell types forming the mature central nervous system (CNS) are now understood to be diverse. This cellular subtype diversity originates to a large extent from the specification of the earlier proliferating progenitor populations during development. Here, we review the processes governing the differentiation of a common neuroepithelial cell progenitor pool into mature neurons, astrocytes, oligodendrocytes, ependymal cells and adult stem cells. We focus on studies performed in mice and involving two distinct CNS structures: the spinal cord and the cerebral cortex. Understanding the origin, specification and developmental regulators of neural cells will ultimately impact comprehension and treatments of neurological disorders and diseases. - Highlights: • Similar mechanisms regulate cell fate in different CNS cell types and structures. • Cell fate regulators operate in a spatial–temporal manner. • Different neural cell types rely on the generation of a diversity of progenitor cells. • Cell fate decision is dictated by the integration of intrinsic and extrinsic signals

  11. Cell fate control in the developing central nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Guérout, Nicolas; Li, Xiaofei; Barnabé-Heider, Fanie, E-mail: Fanie.Barnabe-Heider@ki.se

    2014-02-01

    The principal neural cell types forming the mature central nervous system (CNS) are now understood to be diverse. This cellular subtype diversity originates to a large extent from the specification of the earlier proliferating progenitor populations during development. Here, we review the processes governing the differentiation of a common neuroepithelial cell progenitor pool into mature neurons, astrocytes, oligodendrocytes, ependymal cells and adult stem cells. We focus on studies performed in mice and involving two distinct CNS structures: the spinal cord and the cerebral cortex. Understanding the origin, specification and developmental regulators of neural cells will ultimately impact comprehension and treatments of neurological disorders and diseases. - Highlights: • Similar mechanisms regulate cell fate in different CNS cell types and structures. • Cell fate regulators operate in a spatial–temporal manner. • Different neural cell types rely on the generation of a diversity of progenitor cells. • Cell fate decision is dictated by the integration of intrinsic and extrinsic signals.

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

    Science.gov (United States)

    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.

  13. Cell viability and repair systems in mammal cells

    International Nuclear Information System (INIS)

    Synchronized cell cultures of mice are irradiated with 4,0J/m2 ultraviolet light at different times. The possible mechanisms involved in the recuperation of the cellular survival observed, are discussed. (M.A.)

  14. Cost Analysis of Fuel Cell Systems for Transportation Compressed Hydrogen and PEM Fuel Cell System

    Energy Technology Data Exchange (ETDEWEB)

    Eric J. Carlson

    2004-10-20

    PEMFC technology for transportation must be competitive with internal combustion engine powertrains in a number of key metrics, including performance, life, reliability, and cost. Demonstration of PEMFC cost competitiveness has its own challenges because the technology has not been applied to high volume automotive markets. The key stack materials including membranes, electrodes, bipolar plates, and gas diffusion layers have not been produced in automotive volumes to the exacting quality requirements that will be needed for high stack yields and to the evolving property specifications of high performance automotive stacks. Additionally, balance-of-plant components for air, water, and thermal management are being developed to meet the unique requirements of fuel cell systems. To address the question of whether fuel cells will be cost competitive in automotive markets, the DOE has funded this project to assess the high volume production cost of PEM fuel cell systems. In this report a historical perspective of our efforts in assessment of PEMFC cost for DOE is provided along with a more in-depth assessment of the cost of compressed hydrogen storage is provided. Additionally, the hydrogen storage costs were incorporated into a system cost update for 2004. Assessment of cost involves understanding not only material and production costs, but also critical performance metrics, i.e., stack power density and associated catalyst loadings that scale the system components. We will discuss the factors influencing the selection of the system specification (i.e., efficiency, reformate versus direct hydrogen, and power output) and how these have evolved over time. The reported costs reflect internal estimates and feedback from component developers and the car companies. Uncertainty in the cost projection was addressed through sensitivity analyses.

  15. Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Kathyayani

    2011-10-04

    Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

  16. Single cell deposition and patterning with a robotic system.

    Directory of Open Access Journals (Sweden)

    Zhe Lu

    Full Text Available Integrating single-cell manipulation techniques in traditional and emerging biological culture systems is challenging. Microfabricated devices for single cell studies in particular often require cells to be spatially positioned at specific culture sites on the device surface. This paper presents a robotic micromanipulation system for pick-and-place positioning of single cells. By integrating computer vision and motion control algorithms, the system visually tracks a cell in real time and controls multiple positioning devices simultaneously to accurately pick up a single cell, transfer it to a desired substrate, and deposit it at a specified location. A traditional glass micropipette is used, and whole- and partial-cell aspiration techniques are investigated to manipulate single cells. Partially aspirating cells resulted in an operation speed of 15 seconds per cell and a 95% success rate. In contrast, the whole-cell aspiration method required 30 seconds per cell and achieved a success rate of 80%. The broad applicability of this robotic manipulation technique is demonstrated using multiple cell types on traditional substrates and on open-top microfabricated devices, without requiring modifications to device designs. Furthermore, we used this serial deposition process in conjunction with an established parallel cell manipulation technique to improve the efficiency of single cell capture from ∼80% to 100%. Using a robotic micromanipulation system to position single cells on a substrate is demonstrated as an effective stand-alone or bolstering technology for single-cell studies, eliminating some of the drawbacks associated with standard single-cell handling and manipulation techniques.

  17. Structure and function of stem cell pools in mammalian cell renewal systems

    International Nuclear Information System (INIS)

    Stem cells play a key-role in the maintenance of the equilibrium between cell loss and cell production in cell renewal systems as well as in the understanding of the radiation pathophysiology of mammalian organisms. The integrity of mammalian organisms with the need to maintain a constant ''millieu interior'' is depending on the normal functioning of cell renewal systems, especially those of epithelial surfaces and blood cell forming organs. All cell renewal systems of bodies have a very similar functional structure consisting of functional, proliferative - amplifying and stem cell compartments. They differ in transit and cell cycle times and in the number of amplification division - aside from the difference in their functional and biochemical make-up. The stem cell pools are providing the cells capable of differentiation without depleting their own kind. This can be achieved by symmetrical or assymmetrical stem cell division. In normal steady state, 50% of the stem cell division remain in the stem cell pool, while the other 50% leave it to differentiate, proliferate and mature, hemopoietic system is distributed throughout bodies. This is an important factor in the radiation biology of mammalian organisms since the loss of function in one area can be compensated for by more production in other areas, and locally depleted sites can be reseeded with the stem cells migrating in from blood. (Yamashita, S.)

  18. Cell death in the cardiovascular system

    OpenAIRE

    Clarke, Murray; Bennett, Martin; Littlewood, Trevor

    2006-01-01

    Cell death is important for both development and tissue homeostasis in the adult. As such, it is tightly controlled and deregulation is associated with diverse pathologies; for example, regulated cell death is involved in vessel remodelling during development or following injury, but deregulated death is implicated in pathologies such as atherosclerosis, aneurysm formation, ischaemic and dilated cardiomyopathies and infarction. We describe the mechanisms of cell death and its role in the norm...

  19. Measuring cell identity in noisy biological systems

    OpenAIRE

    Birnbaum, Kenneth D; Kussell, Edo

    2011-01-01

    Global gene expression measurements are increasingly obtained as a function of cell type, spatial position within a tissue and other biologically meaningful coordinates. Such data should enable quantitative analysis of the cell-type specificity of gene expression, but such analyses can often be confounded by the presence of noise. We introduce a specificity measure Spec that quantifies the information in a gene's complete expression profile regarding any given cell type, and an uncertainty me...

  20. Neuronal chemokines : Versatile messengers in central nervous system cell interaction

    NARCIS (Netherlands)

    de Haas, A. H.; van Weering, H. R. J.; de Jong, E. K.; Boddeke, H. W. G. M.; Biber, K. P. H.

    2007-01-01

    Whereas chemokines are well known for their ability to induce cell migration, only recently it became evident that chemokines also control a variety of other cell functions and are versatile messengers in the interaction between a diversity of cell types. In the central nervous system (CNS), chemoki

  1. Comparative analysis of eukaryotic cell-free expression systems.

    Science.gov (United States)

    Hartsough, Emily M; Shah, Pankti; Larsen, Andrew C; Chaput, John C

    2015-09-01

    Cell-free protein synthesis (CFPS) allows researchers to rapidly generate functional proteins independent of cell culture. Although advances in eukaryotic lysates have increased the amount of protein that can be produced, the nuances of different translation systems lead to variability in protein production. To help overcome this problem, we have compared the relative yield and template requirements for three commonly used commercial cell-free translation systems: wheat germ extract (WGE), rabbit reticulocyte lysate (RRL), and HeLa cell lysate (HCL). Our results provide a general guide for researchers interested in using cell-free translation to generate recombinant protein for biomedical applications. PMID:26345507

  2. Cell-to-cell variability in cell death: can systems biology help us make sense of it all?

    OpenAIRE

    Xia, X; Owen, M. S.; Lee, R E C; Gaudet, S

    2014-01-01

    One of the most common observations in cell death assays is that not all cells die at the same time, or at the same treatment dose. Here, using the perspective of the systems biology of apoptosis and the context of cancer treatment, we discuss possible sources of this cell-to-cell variability as well as its implications for quantitative measurements and computational models of cell death. Many different factors, both within and outside of the apoptosis signaling networks, have been correlated...

  3. Microfluidics-based laser cell-micropatterning system

    International Nuclear Information System (INIS)

    The ability to place individual cells into an engineered microenvironment in a cell-culture model is critical for the study of in vivo relevant cell–cell and cell–extracellular matrix interactions. Microfluidics provides a high-throughput modality to inject various cell types into a microenvironment. Laser guided systems provide the high spatial and temporal resolution necessary for single-cell micropatterning. Combining these two techniques, the authors designed, constructed, tested and evaluated (1) a novel removable microfluidics-based cell-delivery biochip and (2) a combined system that uses the novel biochip coupled with a laser guided cell-micropatterning system to place individual cells into both two-dimensional (2D) and three-dimensional (3D) arrays. Cell-suspensions of chick forebrain neurons and glial cells were loaded into their respective inlet reservoirs and traversed the microfluidic channels until reaching the outlet ports. Individual cells were trapped and guided from the outlet of a microfluidic channel to a target site on the cell-culture substrate. At the target site, 2D and 3D pattern arrays were constructed with micron-level accuracy. Single-cell manipulation was accomplished at a rate of 150 μm s−1 in the radial plane and 50 μm s−1 in the axial direction of the laser beam. Results demonstrated that a single-cell can typically be patterned in 20–30 s, and that highly accurate and reproducible cellular arrays and systems can be achieved through coupling the microfluidics-based cell-delivery biochip with the laser guided system. (paper)

  4. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...

  5. Air intake and exhaust systems in fuel cell engines

    Energy Technology Data Exchange (ETDEWEB)

    Fuesser, R.; Weber, O. [Mann and Hummel (Germany)

    1999-07-01

    This paper describes the design and development of the air intake and exhaust system of a fuel cell powered road vehicle. In this instance the automotive supplier designed both the air intake and the exhaust system. The fuel cell engine gives a cold combustion effect making it possible to manufacture the exhaust from plastic materials. (UK)

  6. Design and Control of High Temperature PEM Fuel Cell System

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl

    often during a normal driving cycle. The combination of batteries and super capacitors together with fuel cells can improve the system performance, lifetime and cost. Simple systems can be designed where the fuel cells and batteries are directly connected, but the introduction of power electronics can...

  7. Overview of Production of Protein Using Cell-free Systems

    OpenAIRE

    Gao, Fei Philip

    2014-01-01

    One of the most important steps in protein research is production of the target protein. Cell based systems are mature tools that have long been used to express recombinant proteins by manipulation of the expression organisms. However, it is often challenging to find suitable cell systems that allow for rapid screening of conditions and constructs to produce properly folded, functional proteins in a cost effective manner. As a result, cell-free protein production emerged as an attractive alte...

  8. Fuel Cells: Power System Option for Space Research

    Science.gov (United States)

    Shaneeth, M.; Mohanty, Surajeet

    2012-07-01

    Fuel Cells are direct energy conversion devices and, thereby, they deliver electrical energy at very high efficiency levels. Hydrogen and Oxygen gases are electrochemically processed, producing clean electric power with water as the only by product. A typical, Fuel Cell based power system involve a Electrochemical power converter, gas storage and management systems, thermal management systems and relevant control units. While there exists different types of Fuel cells, Proton Exchange Membrane (PEM) Fuel Cells are considered as the most suitable one for portable applications. Generally, Fuel Cells are considered as the primary power system option in space missions requiring high power ( > 5kW) and long durations and also where water is a consumable, such as manned missions. This is primarily due to the advantage that fuel cell based power systems offer, in terms of specific energy. Fuel cells have the potential to attain specific energy > 500Wh/kg, specific power >500W/kg, energy density > 400Whr/L and also power density > 200 W/L. This apart, a fuel cell system operate totally independent of sun light, whereas as battery based system is fully dependent on the same. This uniqueness provides added flexibility and capabilities to the missions and modularity for power system. High power requiring missions involving reusable launch vehicles, manned missions etc are expected to be richly benefited from this. Another potential application of Fuel Cell would be interplanetary exploration. Unpredictable and dusty atmospheres of heavenly bodies limits sun light significantly and there fuel cells of different types, eg, Bio-Fuel Cells, PEMFC, DMFCs would be able to work effectively. Manned or unmanned lunar out post would require continuous power even during extra long lunar nights and high power levels are expected. Regenerative Fuel Cells, a combination of Fuel Cells and Electrolysers, are identified as strong candidate. While application of Fuel Cells in high power

  9. Alkaline fuel cells for the regenerative fuel cell energy storage system

    Science.gov (United States)

    Martin, R. E.

    1983-01-01

    The development of the alkaline Regenerative Fuel Cell System, whose fuel cell module would be a derivative of the 12-kW fuel cell power plant currently being produced for the Space Shuttle Orbiter, is reviewed. Long-term endurance testing of full-size fuel cell modules has demonstrated: (1) the extended endurance capability of potassium titanate matrix cells, (2) the long-term performance stability of the anode catalyst, and (3) the suitability of a lightweight graphite structure for use at the anode. These approaches, developed in the NASA-sponsored fuel cell technology advancement program, would also reduce cell weight by nearly one half.

  10. Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Gonda, Steve R.; Kleis, Stanley J.; Geffert, Sandara K.

    2010-01-01

    A prototype miniature bioreactor system is designed to serve as a laboratory benchtop cell-culturing system that minimizes the need for relatively expensive equipment and reagents and can be operated under computer control, thereby reducing the time and effort required of human investigators and reducing uncertainty in results. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere at a controlled temperature, and associated control subsystems. The system can be used to culture both anchorage-dependent and suspension cells, which can be either prokaryotic or eukaryotic. Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. By integrating this system with one or more microanalytical instrument(s), one can construct a complete automated analytical system that can be tailored to perform one or more of a large variety of assays.

  11. Neutrophils and macrophages: The main partners of phagocyte cell systems

    Directory of Open Access Journals (Sweden)

    Manuel T. Silva

    2012-07-01

    Full Text Available Biological cellular systems are groups of cells sharing a set of characteristics, mainly key function and origin. Phagocytes are crucial in the host defense against microbial infection. The previously proposed phagocyte cell systems including the most recent and presently prevailing one, the Mononuclear Phagocyte System (MPS, grouped mononuclear cells but excluded neutrophils, creating an unacceptable situation. As neutrophils are archetypical phagocytes that must be members of comprehensive phagocyte systems, M. T. Silva recently proposed the creation of a Myeloid Phagocyte System (MYPS that adds neutrophils to the MPS. The phagocytes grouped in the MYPS include the leukocytes neutrophils, inflammatory monocytes, macrophages and immature myeloid DCs. Here the justifications behind the inclusion of neutrophils in a phagocyte system is expanded and the MYPS are further characterized as a group of dedicated phagocytic cells that function in an interacting and cooperative way in the host defense against microbial infection. Neutrophils and macrophages are considered the main arms of this system.

  12. Two-dimensional diffusion limited system for cell growth

    International Nuclear Information System (INIS)

    A new cell system, the ''sandwich'' system, was developed to supplement multicellular spheroids as tumor analogues. Sandwiches allow new experimental approaches to questions of diffusion, cell cycle effects and radiation resistance in tumors. In this thesis the method for setting up sandwiches is described both theoretically and experimentally followed by its use in x-ray irradiation studies. In the sandwich system, cells are grown in a narrow gap between two glass slides. Where nutrients and waste products can move into or out of the local environment of the cells only by diffusing through the narrow gap between the slides. Due to the competition between cells, self-created gradients of nutrients and metabolic products are set up resulting in a layer of cells which resembles a living spheroid cross section. Unlike the cells of the spheroid, however, cells in all regions of the sandwich are visible. Therefore, the relative sizes of the regions and their time-dependent growth can be monitored visually without fixation or sectioning. The oxygen and nutrient gradients can be ''turned off'' at any time without disrupting the spatial arrangement of the cells by removing the top slide of the assembly and subsequently turned back on if desired. Removal of the top slide also provides access to all the cells, including those near the necrotic center, of the sandwich. The cells can then be removed for analysis outside the sandwich system. 61 refs., 17 figs

  13. Two-dimensional diffusion limited system for cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Hlatky, L.

    1985-11-01

    A new cell system, the ''sandwich'' system, was developed to supplement multicellular spheroids as tumor analogues. Sandwiches allow new experimental approaches to questions of diffusion, cell cycle effects and radiation resistance in tumors. In this thesis the method for setting up sandwiches is described both theoretically and experimentally followed by its use in x-ray irradiation studies. In the sandwich system, cells are grown in a narrow gap between two glass slides. Where nutrients and waste products can move into or out of the local environment of the cells only by diffusing through the narrow gap between the slides. Due to the competition between cells, self-created gradients of nutrients and metabolic products are set up resulting in a layer of cells which resembles a living spheroid cross section. Unlike the cells of the spheroid, however, cells in all regions of the sandwich are visible. Therefore, the relative sizes of the regions and their time-dependent growth can be monitored visually without fixation or sectioning. The oxygen and nutrient gradients can be ''turned off'' at any time without disrupting the spatial arrangement of the cells by removing the top slide of the assembly and subsequently turned back on if desired. Removal of the top slide also provides access to all the cells, including those near the necrotic center, of the sandwich. The cells can then be removed for analysis outside the sandwich system. 61 refs., 17 figs.

  14. A fully automated system for adherent cells microinjection.

    Science.gov (United States)

    Becattini, Gabriele; Mattos, Leonardo S; Caldwell, Darwin G

    2014-01-01

    This paper proposes an automated robotic system to perform cell microinjections to relieve human operators from this highly difficult and tedious manual procedure. The system, which uses commercial equipment currently found on most biomanipulation laboratories, consists of a multitask software framework combining computer vision and robotic control elements. The vision part features an injection pipette tracker and an automatic cell targeting system that is responsible for defining injection points within the contours of adherent cells in culture. The main challenge is the use of bright-field microscopy only, without the need for chemical markers normally employed to highlight the cells. Here, cells are identified and segmented using a threshold-based image processing technique working on defocused images. Fast and precise microinjection pipette positioning over the automatically defined targets is performed by a two-stage robotic system which achieves an average injection rate of 7.6 cells/min with a pipette positioning precision of 0.23 μm. The consistency of these microinjections and the performance of the visual targeting framework were experimentally evaluated using two cell lines (CHO-K1 and HEK) and over 500 cells. In these trials, the cells were automatically targeted and injected with a fluorescent marker, resulting in a correct cell detection rate of 87% and a successful marker delivery rate of 67.5%. These results demonstrate that the new system is capable of better performances than expert operators, highlighting its benefits and potential for large-scale application. PMID:24403406

  15. Red cell transfusion and the immune system.

    Science.gov (United States)

    Hart, S; Cserti-Gazdewich, C M; McCluskey, S A

    2015-01-01

    Understanding the complex immunological consequences of red cell transfusion is essential if we are to use this valuable resource wisely and safely. The decision to transfuse red cells should be made after serious considerations of the associated risks and benefits. Immunological risks of transfusion include major incompatibility reactions and transfusion-related acute lung injury, while other immunological insults such as transfusion-related immunomodulation are relatively underappreciated. Red cell transfusions should be acknowledged as immunological exposures, with consequences weighed against expected benefits. This article reviews immunological consequences and the emerging evidence that may inform risk-benefit considerations in clinical practice. PMID:25440393

  16. A Web-Server of Cell Type Discrimination System

    Directory of Open Access Journals (Sweden)

    Anyou Wang

    2014-01-01

    Full Text Available Discriminating cell types is a daily request for stem cell biologists. However, there is not a user-friendly system available to date for public users to discriminate the common cell types, embryonic stem cells (ESCs, induced pluripotent stem cells (iPSCs, and somatic cells (SCs. Here, we develop WCTDS, a web-server of cell type discrimination system, to discriminate the three cell types and their subtypes like fetal versus adult SCs. WCTDS is developed as a top layer application of our recent publication regarding cell type discriminations, which employs DNA-methylation as biomarkers and machine learning models to discriminate cell types. Implemented by Django, Python, R, and Linux shell programming, run under Linux-Apache web server, and communicated through MySQL, WCTDS provides a friendly framework to efficiently receive the user input and to run mathematical models for analyzing data and then to present results to users. This framework is flexible and easy to be expended for other applications. Therefore, WCTDS works as a user-friendly framework to discriminate cell types and subtypes and it can also be expended to detect other cell types like cancer cells.

  17. A web-server of cell type discrimination system.

    Science.gov (United States)

    Wang, Anyou; Zhong, Yan; Wang, Yanhua; He, Qianchuan

    2014-01-01

    Discriminating cell types is a daily request for stem cell biologists. However, there is not a user-friendly system available to date for public users to discriminate the common cell types, embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and somatic cells (SCs). Here, we develop WCTDS, a web-server of cell type discrimination system, to discriminate the three cell types and their subtypes like fetal versus adult SCs. WCTDS is developed as a top layer application of our recent publication regarding cell type discriminations, which employs DNA-methylation as biomarkers and machine learning models to discriminate cell types. Implemented by Django, Python, R, and Linux shell programming, run under Linux-Apache web server, and communicated through MySQL, WCTDS provides a friendly framework to efficiently receive the user input and to run mathematical models for analyzing data and then to present results to users. This framework is flexible and easy to be expended for other applications. Therefore, WCTDS works as a user-friendly framework to discriminate cell types and subtypes and it can also be expended to detect other cell types like cancer cells. PMID:24578634

  18. Towards systems thinking in cell biology education

    OpenAIRE

    Verhoeff, Roald Pieter

    2003-01-01

    Students are taught a large variety of life structures and processes at the cellular level. The concepts used to describe them are mainly drawn from the sub-cellular level, but this knowledge seems to be fragmentary if its integration at the cellular and organismic level remains undone. As a consequence, many students fail to acquire coherent conceptual understanding of the cell as a basic and functional unit of the organism. To enhance the coherence in students’ cell biological knowledge we ...

  19. Alkaline regenerative fuel cell systems for energy storage

    Science.gov (United States)

    Schubert, F. H.; Reid, M. A.; Martin, R. E.

    1981-01-01

    A description is presented of the results of a preliminary design study of a regenerative fuel cell energy storage system for application to future low-earth orbit space missions. The high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. In addition to providing energy storage, the system can provide hydrogen and oxygen for attitude control of the satellite and for life support. During the daylight portion of the orbit the electrolysis module uses power provided by the solar array to generate H2 and O2 from the product water produced by the fuel cell module. The fuel cell module supplies electrical power during the dark period of the orbit.

  20. Investigation of the photovoltaic cell/ thermoelectric element hybrid system performance

    Science.gov (United States)

    Cotfas, D. T.; Cotfas, P. A.; Machidon, O. M.; Ciobanu, D.

    2016-06-01

    The PV/TEG hybrid system, consisting of the photovoltaic cells and thermoelectric element, is presented in the paper. The dependence of the PV/TEG hybrid system parameters on the illumination levels and the temperature is analysed. The maxim power values of the photovoltaic cell, of the thermoelectric element and of the PV/TEG system are calculated and a comparison between them is presented and analysed. An economic analysis is also presented.

  1. Usability and Applicability of Microfluidic Cell Culture Systems

    DEFF Research Database (Denmark)

    Hemmingsen, Mette

    devices still lack general implementation into biological research laboratories. In this project, the usability and applicability of microfluidic cell culture systems have been investigated. The tested systems display good properties regarding optics and compatibility with standard laboratory equipment...... possibilities for, for example, precise control of the chemical environment, 3D cultures, controlled co-culture of different cell types or automated, individual control of up to 96 cell culture chambers in one integrated system. Despite the great new opportunities to perform novel experimental designs, these...... shown to be needed. This is possibly one of the reasons for the lack of implementation of microfluidic cell culture systems into biological research laboratories. Procedures to perform long-term microfluidic perfusion cell culture experiments have been established. Furthermore, successful application of...

  2. Biona-C Cell Culture pH Monitoring System

    Science.gov (United States)

    Friedericks, C.

    1999-01-01

    Sensors 2000! is developing a system to demonstrate the ability to perform accurate, real-time measurements of pH and CO2 in a cell culture media in Space. The BIONA-C Cell Culture pH Monitoring System consists of S2K! developed ion selective sensors and control electronics integrated with the fluidics of a cell culture system. The integrated system comprises a "rail" in the Cell Culture Module (CCM) of WRAIR (Space Biosciences of Walter Read Army Institute of Research). The CCM is a Space Shuttle mid-deck locker experiment payload. The BIONA-C is displayed along with associated graphics and text explanations. The presentation will stimulate interest in development of sensor technology for real-time cell culture measurements. The transfer of this technology to other applications will also be of interest. Additional information is contained in the original document.

  3. Laser grooved buried contact cells optimised for linear concentration systems

    Energy Technology Data Exchange (ETDEWEB)

    Vivar, M.; Anton, I.; Sala, G. [Instituto de Energia Solar, UPM, Ciudad Universitaria S/N, 28040 Madrid (Spain); Morilla, C.; Fernandez, J.M. [BP Solar Espana, Pol. Ind. Tres Cantos, s/n Zona Oeste, 28760 Tres Cantos, Madrid (Spain)

    2010-02-15

    Laser grooved buried contact silicon solar cells can be optimised for use in linear concentration systems at low cost. Optimising the groove depth, the copper thickness and the finger pitch by using the Design of Experiments (DOE) experimental methodology can lead to a dramatic reduction of the cell series resistance. This type of cell can be optimised for each application in an industrial line with few changes. For the EUCLIDES III linear concentrator system, optimised cell efficiency metrics for 51 x 116 mm units are in the range of 18-19% at the 40 x concentration level. (author)

  4. [Gas cooled fuel cell systems technology development program

    Energy Technology Data Exchange (ETDEWEB)

    1988-03-01

    Objective is the development of a gas-cooled phosphoric acid fuel cell for electric utility power plant application. Primary objectives are to: demonstrate performance endurance in 10-cell stacks at 70 psia, 190 C, and 267 mA/cm[sup 2]; improve cell degradation rate to less than 8 mV/1000 hours; develop cost effective criteria, processes, and design configurations for stack components; design multiple stack unit and a single 100 kW fuel cell stack; design a 375 kW fuel cell module and demonstrate average cell beginning-of-use performance; manufacture four 375-kW fuel cell modules and establish characteristics of 1.5 MW pilot power plant. The work is broken into program management, systems engineering, fuel cell development and test, facilities development.

  5. Novel Fuel Cells for Coal Based Systems

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Tao

    2011-12-31

    The goal of this project was to acquire experimental data required to assess the feasibility of a Direct Coal power plant based upon an Electrochemical Looping (ECL) of Liquid Tin Anode Solid Oxide Fuel Cell (LTA-SOFC). The objective of Phase 1 was to experimentally characterize the interaction between the tin anode, coal fuel and cell component electrolyte, the fate of coal contaminants in a molten tin reactor (via chemistry) and their impact upon the YSZ electrolyte (via electrochemistry). The results of this work will provided the basis for further study in Phase 2. The objective of Phase 2 was to extend the study of coal impurities impact on fuel cell components other than electrolyte, more specifically to the anode current collector which is made of an electrically conducting ceramic jacket and broad based coal tin reduction. This work provided a basic proof-of-concept feasibility demonstration of the direct coal concept.

  6. Microfluidic systems and methods for transport and lysis of cells and analysis of cell lysate

    Science.gov (United States)

    Culbertson, Christopher T [Oak Ridge, TN; Jacobson, Stephen C [Knoxville, TN; McClain, Maxine A [Knoxville, TN; Ramsey, J Michael [Knoxville, TN

    2008-09-02

    Microfluidic systems and methods are disclosed which are adapted to transport and lyse cellular components of a test sample for analysis. The disclosed microfluidic systems and methods, which employ an electric field to rupture the cell membrane, cause unusually rapid lysis, thereby minimizing continued cellular activity and resulting in greater accuracy of analysis of cell processes.

  7. T cells fail to develop in the human skin-cell explants system; an inconvenient truth

    OpenAIRE

    Vanderlocht Joris; Lumeij Stijn BJ; Tonnaer Siebe; van der Stegen Sjoukje JC; Huijskens Mirelle JAJ; Van Elssen Catharina HMJ; Meek Bob; Kirkland Mark A; Hesselink Reinout; Germeraad Wilfred TV; Bos Gerard MJ

    2011-01-01

    Abstract Background Haplo-identical hematopoietic stem cell (HSC) transplantation is very successful in eradicating haematological tumours, but the long post-transplant T-lymphopenic phase is responsible for high morbidity and mortality rates. Clark et al. have described a skin-explant system capable of producing host-tolerant donor-HSC derived T-cells. Because this T-cell production platform has the potential to replenish the T-cell levels following transplantation, we set out to validate th...

  8. Fuel cells and electrolysers in future energy systems

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad

    energy sys‐ tems, the direction in which these systems develop must be considered. In this dissertation, fuel cells are analysed in the context of energy systems that are gradually changing from the current design, with large amounts of fossil fuel combustion technologies, to a future design based on 100......Efficient fuel cells and electrolysers are still at the development stage. In this dissertation, future developed fuel cells and electrolysers are analysed in future renewable energy sys‐ tems. Today, most electricity, heat and transport demands are met by combustion tech‐ nologies. Compared to...... these conventional technologies, fuel cells have the ability to signifi‐ cantly increase the efficiency of the system while meeting such demands. However, energy system designs can be identified in which the fuel savings achieved are lost in technologies elsewhere in the system. This dissertation is...

  9. Visual Servoed Three-Dimensional Cell Rotation System.

    Science.gov (United States)

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

    2015-10-01

    Three-dimensional (3-D) positioning and orientation of embryos/oocytes is necessary to facilitate micromanipulation tasks such as cell injection and cellular structural biopsy commonly performed under a microscope. Conventional cell orientation is performed manually by using a vacuum equipped micropipette to aspirate and release the cell, which is a trial-and-error approach. The conventional method relies heavily on the skill of the operator; it also suffers from low precision, low success rate and low controllability. These drawbacks illustrate the need for a systematic 3-D cell rotational system to automate the cell orientation process. In this paper, we present a noninvasive single cell rotation system that can automatically orientate a zebrafish embryo to a desired position when both the cytoplasm and the yolk are in the focal plane. A three-point-contact model for cell rotation that involves a custom-designed rotational stage is introduced to provide precise rotational position control. A vision recognition algorithm is also proposed to enable the visual servoing function of the system. Experimental results show that the proposed system can achieve high success rates of 92.5% (x-axis rotation with 40 trails) and 97.5% (about the z-axis with 80 trails). The system can also successfully complete 3-D cell orientation at an average speed of 31 s/cell with a high in-plane rotation accuracy of 0.3 (°) . As a high precise, high controllable and deterministic cell manipulating system, it provides a starting point for automated cell manipulation for intracytoplasmic sperm injection and embryo biopsy for preimplantation genetic diagnosis. PMID:25993702

  10. Systemic mastocytosis in a patient with ovarian germ cell carcinoma and mast cell leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Sun, G.; Hajianpour, M.J.; Hajianpour, A.K. [Alfigen/The Genetics Institute, Pasadena, CA (United States)] [and others

    1994-09-01

    We report a 12-year-old female with a history of mixed germ cell carcinoma of the right ovary who developed a generalized skin rash after oophorectomy and chemotherapy. She also presented with periodic episodes of flushing, anemia, tachycardia, shortness of breath, high fever, hepatosplenomegaly, nausea, abdominal cramping with diarrhea, and a papuloerythematous skin rash. There was no evidence of secondary carcinoma. Skin biopsy revealed nonspecific inflammatory cells with negative staining for mast cells. Peripheral blood smear showed an increased number of mast cells, thrombocytopenia and normal white cells count. Bone marrow showed hypercellularity with 38% of the nucleated cells being mast cells. Bone marrow chromosome analysis revealed hyperdiploidy in 30% of the cells: 58-64,XX, +1, +2, +5, +6, +7, +8, +14, +16, +18, +19, +19, +20, +21, +22. She expired two months after the occurrence of systemic mastocytosis. Systemic mastocytosis has been reported in association with hematopoietic disorders and with germ cell tumors. The association between mediastinal germ cell tumors and hematological malignancies has also been observed. To our knowledge, combination of most cell leukemia, systemic mastocytosis, and ovarian germ cell carcinoma has not been observed. It is know that mutations at the locus of either proto-oncogene c-kit receptor or its ligand, mast/stem cell factor (SCF) may impair the development of three stem cell populations: hematopoietic stem cells, germ cells and melanoblasts. There have been also extensive investigations on the expression and modulation of the SCF/c-kit interaction in various malignancies. Further molecular studies in patients with germ cell tumor/hematopoietic malignancy syndrome are required to delineate underlying mechanisms.

  11. Study on the Architecture of Control System for Manufacturing Cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The depiction of the agile manufacturing cell includes a synopsis of some of the change proficiencies obtained by the configuration. To achieve agile configuration, the cell control system for agile manufacturing must be rapidly and efficiently generated or modified. In this paper, the object-oriented architecture is defined that supports design and implementation of highly reconfigurable control systems for agile manufacturing cells, which is composed of database objects, control objects, and resource objects, so as to reduce costs and to increase the control system's agility with respect to changing environment.

  12. Characterization and Modeling of a Methanol Reforming Fuel Cell System

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart

    topologies is the Reformed Methanol Fuel Cell (RMFC) system that operates on a mix of methanol and water. The fuel is reformed with a steam reforming to a hydrogen rich gas, however with additional formation of Carbon Monoxide and Carbon Dioxide. High Temperature Polymer Electrolyte Membrane Fuel Cell (HT...... to heat up the steam reforming process. However, utilizing the excess hydrogen in the system complicates the RMFC system as the amount of hydrogen can vary depending on the fuel methanol supply, fuel cell load and the reformer gas composition. This PhD study has therefore been involved in...

  13. Process modeling of fuel cell vehicle power system

    Institute of Scientific and Technical Information of China (English)

    CHEN LiMing; LIN ZhaoJia; MA ZiFeng

    2009-01-01

    Constructed here is a mathematic model of PEM Fuel Cell Vehicle Power System which is composed of fuel supply model, fuel cell stack model and water-heat management model. The model was developed by Matiab/Simulink to evaluate how the major operating variables affect the output performances. Itshows that the constructed model can represent characteristics of the power system closely by comparing modeling results with experimental data, and it can be used in the study and design of fuel cell vehicle power system.

  14. Research on Software-Cell-Based Software System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The aim of research on software architecture is to improve the quality attributes of software sys tems, such as security, reliability, maintainability, testability , reassembility , evolvability. However, a sin gle running system is hard to achieve all these goals. In this paper, software-cell is introduced as the basic u nit throughout developing process. Then it is further advanced that a robust, safe and high-quality software system is composed of a running system and four supportive systems. This paper especially discusses the structure of software-cell, the construction of the five systems, and the relations between them.

  15. PDMS/glass microfluidic cell culture system for cytotoxicity tests and cells passage

    DEFF Research Database (Denmark)

    Ziolkowska, K.; Jedrych, E.; Kwapiszewski, R.; Lopacinska, Joanna M.; Skolimowski, Maciej; Chudy, M.

    2010-01-01

    In this paper, hybrid (PDMS/glass) microfluidic cell culture system (MCCS) integrated with the concentration gradient generator (CGG) is presented. PDMS gas permeability enabled cells' respiration in the fabricated microdevices and excellent glass hydrophilicity allowed successful cells' seeding....... The human lung carcinoma cells (A549) were cultured in the microdevice for several days. The growth and proliferation of cells was monitored using an inverted fluorescence microscope. After the cells' confluence was achieved in the microchambers, the novel method of cells' passaging in the designed...... microdevice was developed and successfully tested. The MCCS microdevice is fully reusable, i.e. it can be used several times for various cell culture and cytotoxic experiments. The suitability of designed MCCS for cell-based cytotoxicity assay application was verified using 1,4-dioxane as a model toxic agent...

  16. A Good Neighborhood for Cells: Bioreactor Demonstration System (BDS-05)

    Science.gov (United States)

    Chung, Leland W. K.; Goodwin, Thomas J. (Technical Monitor)

    2002-01-01

    Good neighborhoods help you grow. As with a city, the lives of a cell are governed by its neighborhood connections Connections that do not work are implicated in a range of diseases. One of those connections - between prostate cancer and bone cells - will be studied on STS-107 using the Bioreactor Demonstration System (BDS-05). To improve the prospects for finding novel therapies, and to identify biomarkers that predict disease progression, scientists need tissue models that behave the same as metastatic or spreading cancer. This is one of several NASA-sponsored lines of cell science research that use the microgravity environment of orbit in an attempt to grow lifelike tissue models for health research. As cells replicate, they "self associate" to form a complex matrix of collagens, proteins, fibers, and other structures. This highly evolved microenvironment tells each cell who is next door, how it should grow arid into what shapes, and how to respond to bacteria, wounds, and other stimuli. Studying these mechanisms outside the body is difficult because cells do not easily self-associate outside a natural environment. Most cell cultures produce thin, flat specimens that offer limited insight into how cells work together. Ironically, growing cell cultures in the microgravity of space produces cell assemblies that more closely resemble what is found in bodies on Earth. NASA's Bioreactor comprises a miniature life support system and a rotating vessel containing cell specimens in a nutrient medium. Orbital BDS experiments that cultured colon and prostate cancers have been highly promising.

  17. Polygeneration system based on low temperature solid oxide fuel cell/micro gas turbine hybrid system

    OpenAIRE

    Samavati, Mahrokh

    2012-01-01

    Polygeneration systems attract attention recently because of their high efficiency and low emission compare to the conventional power generation technology. Three different polygeneration systems based on low temperature solid oxide fuel cell, atmospheric solid oxide fuel cell/ micro gas turbine, and pressurized solid oxide fuel cell/ micro gas turbine are mathematically modeled in this study using MATLAB (version 7.12.0.635). These systems are designed to provide space heating, cooling and h...

  18. Respiratory systems of the Bacillus cereus mother cell and forespore.

    OpenAIRE

    Escamilla, J E; R. Ramírez; Del-Arenal, P; Aranda, A.

    1986-01-01

    The respiratory systems of the mother cells and forespores of Bacillus cereus were compared throughout the maturation stages (III to VI) of sporulation. The results indicated that both cell compartments contain the same assortment of oxidoreductases and cytochromes. However membrane fractions from young forespores were clearly distinct from those of the mother cell, i.e., lower content of cytochrome aa3, lower cytochrome c oxidase activity, higher concentration of cytochrome o, and a lower se...

  19. Monocrystalline silicon solar cells applied in photovoltaic system

    OpenAIRE

    L.A. Dobrzański; A. Drygała; M. Giedroć; Macek, M

    2012-01-01

    Purpose: The aim of the paper is to fabricate the monocrystalline silicon solar cells using the conventional technology by means of screen printing process and to make of them photovoltaic system.Design/methodology/approach: The investigation of current – voltage characteristic to determinate basic electrical properties of monocrystalline silicon solar cells were investigated under Standard Test Condition. Photovoltaic module was produced from solar cells with the largest short-circuit curren...

  20. Epithelial morphogenesis in three-dimensional cell culture system

    OpenAIRE

    Liu, Mengfei; 刘梦菲

    2014-01-01

    In human body, the most common structures formed by epithelial cells are hollow cysts or tubules. The key feature of the cysts and tubules is the central lumen, which is lined by epithelial cell sheets. The central lumen allows material exchange, thus it is indispensable for the proper function of the epithelial tissue. In order to understand the way that the epithelial cells form highly specialized structure, an in vitro three-dimensional (3D) culture system was established. The Caco-2 c...

  1. Power Conversion System Strategies for Fuel Cell Vehicles

    Institute of Scientific and Technical Information of China (English)

    Kaushik Rajashekara

    2005-01-01

    Power electronics is an enabling technology for the development of environmental friendly fuel cell vehicles, and to implement the various vehicle electrical architectures to obtain the best performance. In this paper, power conversion strategies for propulsion and auxiliary power unit applications are described. The power electronics strategies for the successful development of the fuel cell vehicles are presented. The fuel cell systems for propulsion and for auxiliary power unit applications are also discussed.

  2. Neuronal Chemokines: Versatile Messengers In Central Nervous System Cell Interaction

    OpenAIRE

    de Haas, A. H.; van Weering, H. R. J.; Jong, E.K.; Boddeke, H. W. G. M.; Biber, K.P.H.

    2007-01-01

    Whereas chemokines are well known for their ability to induce cell migration, only recently it became evident that chemokines also control a variety of other cell functions and are versatile messengers in the interaction between a diversity of cell types. In the central nervous system (CNS), chemokines are generally found under both physiological and pathological conditions. Whereas many reports describe chemokine expression in astrocytes and microglia and their role in the migration of leuko...

  3. High Temperature PEM Fuel Cell Systems, Control and Diagnostics

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Justesen, Kristian Kjær; Sahlin, Simon Lennart

    fuels utilizes one of the main advantages of the high temperature PEM fuel cell: robustness to fuel quality and impurities. In order for such systems to provide efficient, robust, and reliable energy, proper control strategies are needed. The complexity and nonlinearity of many of the components in such......Various system topologies are available when it comes to designing high temperature PEM fuel cell systems. Very simple system designs are possible using pure hydrogen, and more complex system designs present themselves when alternative fuels are desired, using reformer systems. The use of reformed...... systems allow the development of both simple linear and also advanced fuzzy logic and neural network controllers able to adapt system performance to the ever changing conditions which the systems operate in over their entire lifetime....

  4. Utilization of the computational technic for the promotion and diffusion of the energy conservation practice; Utilizacion de tecnicas computacionales para promocionar y difundir el ahorro de energia

    Energy Technology Data Exchange (ETDEWEB)

    Kemper Valverde, N. [Laboratorio de Inteligencia Artificial, Instituto de Ingenieria, UNAM, Mexico D. F. (Mexico)

    1995-12-31

    In this paper are presented the developments obtained through the application of the new computational technologies in the diffusion and promotion tasks of energy efficient use and conservation. The most relevant aspects are described of three multimedia courses that were designed in order to increase the possibilities of offering personal training in efficient energy technic, as well as to have on hand totally open consulting and interactive tools. The courses that are described are: ``Design of Energy Conservation Programs for the Industry``, ``Energy Conservation in Combustion Equipment`` and ``Energy Cogeneration Technologies.`` On another subject, an analysis is also made of the possibilities for the development and application of expert systems that advise and give support to the work of technicians and engineers dedicated to energy conservation. The main characteristics of an expert system to give support to the energy analysis of lighting industrial systems, malls, buildings and hotels are also described. [Espanol] En este trabajo se presentan los desarrollos obtenidos por la aplicacion de las tareas de difusion y promocion del uso eficiente y ahorro de energia. Se describen los aspectos mas relevantes de tres cursos multimedia que fueron disenados con el objeto de incrementar las posibilidades de brindar capacitacion individualizada en tecnicas energeticas eficientes, asi como de contar con herramientas de consulta totalmente abiertas e interactivas. Los cursos que se describen son: ``Diseno de Programas de Ahorro de Energia en la Industria,`` ``Ahorro de Energia en Equipos de Combustion`` y ``Tecnologias de Cogeneracion de Energia.`` Por otro lado, tambien se hace un analisis de las posibilidades para el desarrollo y aplicacion de sistemas expertos que asesoren y apoyen el trabajo de tecnicos e ingenieros dedicados al ahorro de energia. Se describen las caracteristicas principales de un sistema experto disenado para brindar apoyo en analisis energeticos

  5. Use of bioindicators in the environmental radiological surveillance of Mexican Nuclear Center; Utilizacion de biondicadores en la vigilancia radiologica ambiental del Centro Nuclear de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gaso P, M.I.; Segovia, N.; Herrera, T.; Perez S, E.; Cervantes, M.L.; Quintero, E.; Palacios, J.; Acosta, E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Herrera, T. [UNAM Instituto Biologia, 04510 Ciudad Univ., Mexico D.F. (Mexico)

    1998-07-01

    Cs-137 and K-40 concentrations were determined in soil samples and wild eatable mushrooms at the forest ecosystem of Mexican Nuclear Center and its surrounding area. The evaluation was carried out with a low bottom gamma spectroscopy system including a high-purity Ge detector (HPGe). The local species that showed greater soil-mushroom transference factor, for Cs-137, were Clavariadelphus truncatus, Cortinarius caerulescenc, Gomphus floccosus and Lyophyllum decastes. The Cs-137 levels obtained in the mushroom samples of Nuclear Center, were in general slightly lower than those of adjacent places, which indicates that this Center is not polluting the atmosphere with such radionuclide. (Author)

  6. Development of a stained cell nuclei counting system

    Science.gov (United States)

    Timilsina, Niranjan; Moffatt, Christopher; Okada, Kazunori

    2011-03-01

    This paper presents a novel cell counting system which exploits the Fast Radial Symmetry Transformation (FRST) algorithm [1]. The driving force behind our system is a research on neurogenesis in the intact nervous system of Manduca Sexta or the Tobacco Hornworm, which was being studied to assess the impact of age, food and environment on neurogenesis. The varying thickness of the intact nervous system in this species often yields images with inhomogeneous background and inconsistencies such as varying illumination, variable contrast, and irregular cell size. For automated counting, such inhomogeneity and inconsistencies must be addressed, which no existing work has done successfully. Thus, our goal is to devise a new cell counting algorithm for the images with non-uniform background. Our solution adapts FRST: a computer vision algorithm which is designed to detect points of interest on circular regions such as human eyes. This algorithm enhances the occurrences of the stained-cell nuclei in 2D digital images and negates the problems caused by their inhomogeneity. Besides FRST, our algorithm employs standard image processing methods, such as mathematical morphology and connected component analysis. We have evaluated the developed cell counting system with fourteen digital images of Tobacco Hornworm's nervous system collected for this study with ground-truth cell counts by biology experts. Experimental results show that our system has a minimum error of 1.41% and mean error of 16.68% which is at least forty-four percent better than the algorithm without FRST.

  7. Nanobiocatalysts for biofuel cells and biosensor systems

    Directory of Open Access Journals (Sweden)

    Radivoje M. Prodanović

    2011-10-01

    Full Text Available This overview summarizes the application of enzymes in the manufacture and design of biofuel cells and biosensors. The emphasis will be put on the protein engineering techniques used for improving the properties of enzymes such as nanobiocatalysts, e.g. immobilization orientation, stability, activity and efficiency of electron transfer between immobilized enzymes and electrodes. Some possible applications in the military and some future designs of these electric devices will be discussed as well.

  8. Horizontally rotated cell culture system with a coaxial tubular oxygenator

    Science.gov (United States)

    Wolf, David A. (Inventor); Schwarz, Ray P. (Inventor); Trinh, Tinh T. (Inventor)

    1991-01-01

    The present invention relates to a horizontally rotating bioreactor useful for carrying out cell and tissue culture. For processing of mammalian cells, the system is sterilized and fresh fluid medium, microcarrier beads, and cells are admitted to completely fill the cell culture vessel. An oxygen containing gas is admitted to the interior of the permeable membrane which prevents air bubbles from being introduced into the medium. The cylinder is rotated at a low speed within an incubator so that the circular motion of the fluid medium uniformly suspends the microbeads throughout the cylinder during the cell growth period. The unique design of this cell and tissue culture device was initially driven by two requirements imposed by its intended use for feasibility studies for three dimensional culture of living cells and tissues in space by JSC. They were compatible with microgravity and simulation of microgravity in one G. The vessels are designed to approximate the extremely quiescent low shear environment obtainable in space.

  9. The ubiquitin-proteasome system in glioma cell cycle control

    Directory of Open Access Journals (Sweden)

    Vlachostergios Panagiotis J

    2012-07-01

    Full Text Available Abstract A major determinant of cell fate is regulation of cell cycle. Tight regulation of this process is lost during the course of development and progression of various tumors. The ubiquitin-proteasome system (UPS constitutes a universal protein degradation pathway, essential for the consistent recycling of a plethora of proteins with distinct structural and functional roles within the cell, including cell cycle regulation. High grade tumors, such as glioblastomas have an inherent potential of escaping cell cycle control mechanisms and are often refractory to conventional treatment. Here, we review the association of UPS with several UPS-targeted proteins and pathways involved in regulation of the cell cycle in malignant gliomas, and discuss the potential role of UPS inhibitors in reinstitution of cell cycle control.

  10. Dynamic cell culture system: a new cell cultivation instrument for biological experiments in space

    Science.gov (United States)

    Gmunder, F. K.; Nordau, C. G.; Tschopp, A.; Huber, B.; Cogoli, A.

    1988-01-01

    The prototype of a miniaturized cell cultivation instrument for animal cell culture experiments aboard Spacelab is presented (Dynamic cell culture system: DCCS). The cell chamber is completely filled and has a working volume of 200 microliters. Medium exchange is achieved with a self-powered osmotic pump (flowrate 1 microliter h-1). The reservoir volume of culture medium is 230 microliters. The system is neither mechanically stirred nor equipped with sensors. Hamster kidney (Hak) cells growing on Cytodex 3 microcarriers were used to test the biological performance of the DCCS. Growth characteristics in the DCCS, as judged by maximal cell density, glucose consumption, lactic acid secretion and pH, were similar to those in cell culture tubes.

  11. GATE Center for Automotive Fuel Cell Systems at Virginia Tech

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Douglas [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2011-09-30

    The Virginia Tech GATE Center for Automotive Fuel Cell Systems (CAFCS) achieved the following objectives in support of the domestic automotive industry: Expanded and updated fuel cell and vehicle technologies education programs; Conducted industry directed research in three thrust areas development and characterization of materials for PEM fuel cells; performance and durability modeling for PEM fuel cells; and fuel cell systems design and optimization, including hybrid and plug-in hybrid fuel cell vehicles; Developed MS and Ph.D. engineers and scientists who are pursuing careers related to fuel cells and automotive applications; Published research results that provide industry with new knowledge which contributes to the advancement of fuel cell and vehicle systems commercialization. With support from the Dept. of Energy, the CAFCS upgraded existing graduate course offerings; introduced a hands-on laboratory component that make use of Virginia Tech's comprehensive laboratory facilities, funded 15 GATE Fellowships over a five year period; and expanded our program of industry interaction to improve student awareness of challenges and opportunities in the automotive industry. GATE Center graduate students have a state-of-the-art research experience preparing them for a career to contribute to the advancement fuel cell and vehicle technologies.

  12. Method of operating a direct dme fuel cell system

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a method of operating a fuel cell system comprising one or more fuel cells with a proton exchange membrane, wherein the membrane is composed of a polymeric material comprising acid-doped polybenzimidazole (PBI). The method comprises adjusting the operating...

  13. Micro-electro-mechanical systems phosphoric acid fuel cell

    Science.gov (United States)

    Sopchak, David A.; Morse, Jeffrey D.; Upadhye, Ravindra S.; Kotovsky, Jack; Graff, Robert T.

    2010-12-21

    A phosphoric acid fuel cell system comprising a porous electrolyte support, a phosphoric acid electrolyte in the porous electrolyte support, a cathode electrode contacting the phosphoric acid electrolyte, and an anode electrode contacting the phosphoric acid electrolyte.

  14. High Efficiency Direct Methane Solid Oxide Fuel Cell System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has a defined need for energy dense and highly efficient energy storage and power delivery systems for future space missions. Compared to other fuel cell...

  15. Integrating fuel cell power systems into building physical plants

    Energy Technology Data Exchange (ETDEWEB)

    Carson, J. [KCI Technologies, Inc., Hunt Valley, MD (United States)

    1996-12-31

    This paper discusses the integration of fuel cell power plants and absorption chillers to cogenerate chilled water or hot water/steam for all weather air conditioning as one possible approach to building system applications. Absorption chillers utilize thermal energy in an absorption based cycle to chill water. It is feasible to use waste heat from fuel cells to provide hydronic heating and cooling. Performance regimes will vary as a function of the supply and quality of waste heat. Respective performance characteristics of fuel cells, absorption chillers and air conditioning systems will define relationships between thermal and electrical load capacities for the combined systems. Specifically, this paper develops thermodynamic relationships between bulk electrical power and cooling/heating capacities for combined fuel cell and absorption chiller system in building applications.

  16. Glial cell development and function in the Drosophila visual system

    OpenAIRE

    CHOTARD, CAROLE; Salecker, Iris

    2007-01-01

    In the developing nervous system, building a functional neuronal network relies on coordinating the formation, specification and survival to diverse neuronal and glial cell subtypes. The establishment of neuronal connections further depends on sequential neuron–neuron and neuron–glia interactions that regulate cell-migration patterns and axon guidance. The visual system of Drosophila has a highly regular, retinotopic organization into reiterated interconnected synaptic circuits. It is therefo...

  17. PV-Wind System with Fuel Cell & Electrolyzer

    Directory of Open Access Journals (Sweden)

    Deepa Sharma

    2015-12-01

    Full Text Available In this paper, a detailed modeling and simulation of solar cell/ wind turbine/ fuel cell hybrid power system is developed using a novel topology to complement each other and to alleviate the effects of environmental variations. Comparing with the other sources , the renewable energy is inexhaustible and has non-pollution characteristics. The solar energy, wind power, hydraulic power and tidal energy are natural resources of the interest to generate electrical power. As the wind turbine output power varies with the wind speed and the solar cell output power varies with both the ambient temperature and radiation, a fuel cell with ultra capacitor bank can be integrated to ensure that the system performs under all conditions. Excess wind and solar energies when available are converted to hydrogen using electrolysis for later use in the fuel cell. In this paper dynamic modeling of various components of this isolated system system is presented. Transient responses of the system to step change in the load, ambient temperature, radiation, and wind speed in a number of possible situations are studied. Modeling and simulations are conducted using MATLAB/Simulink software packages to verify the effectiveness of the proposed system. The results show that the proposed hybrid power system can tolerate the rapid change in natural conditions and suppress the effects of these fluctuations on the voltage within the acceptable range.The proposed system can be used for off grid power generation in non interconnected areas or remote isolated communities of nation.

  18. Phase Space Cell in Nonextensive Classical Systems

    OpenAIRE

    Piero Quarati; Francesco Quarati

    2003-01-01

    We calculate the phase space volume $\\Omega$ occupied by a nonextensive system of $N$ classical particles described by an equilibrium (or steady-state, or long-term stationary state of a nonequilibrium system) distribution function, which slightly deviates from Maxwell-Boltzmann (MB) distribution in the high energy tail. We explicitly require that the number of accessible microstates does not change respect to the extensive MB case. We also derive, within a classical scheme, an analytical exp...

  19. Activation of ion transport systems during cell volume regulation

    International Nuclear Information System (INIS)

    This review discusses the activation of transport pathways during volume regulation, including their characteristics, the possible biochemical pathways that may mediate the activation of transport pathways, and the relations between volume regulation and transepithelial transport in renal cells. Many cells regulate their volume when exposed to an anisotonic medium. The changes in cell volume are caused by activation of ion transport pathways, plus the accompanying osmotically driven water movement such that cell volume returns toward normal levels. The swelling of hypertonically shrunken cells is termed regulatory volume increase (RVI) and involves an influx of NaCl into the cell via either activation of Na-Cl, Na-K-2Cl cotransport systems, or Na+-H+ and Cl--HCO3- exchangers. The reshrinking of hypotonically swollen cells is termed regulatory volume decrease (RVD) and involves an efflux of KCl and water from the cell by activation of either separate K+ and Cl- conductances, a K-Cl cotransport system, or parallel K+-H+ and Cl--HCO3- exchangers. The biochemical mechanisms involved in the activation of transport systems are largely unknown, however, the phosphoinositide pathway may be implicated in RVI; phorbol esters, cGMP, and Ca2+ affect the process of volume regulation. Renal tubular cells, as well as the blood cells that transverse the medulla, are subjected to increasing osmotic gradients from the corticomedullary junction to the papillary tip, as well as changing interstitial and tubule fluid osmolarity, depending on the diuretic state of the animal. Medullary cells from the loop of Henle and the papilla can volume regulate by activating Na-K-2Cl cotransport or Na+-H+ and Cl--HCO3- exchange systems

  20. Load measurement system with load cell lock-out mechanism

    Science.gov (United States)

    Le, Thang; Carroll, Monty; Liu, Jonathan

    1995-01-01

    In the frame work of the project Shuttle Plume Impingement Flight Experiment (SPIFEX), a Load Measurement System was developed and fabricated to measure the impingement force of Shuttle Reaction Control System (RCS) jets. The Load Measurement System is a force sensing system that measures any combination of normal and shear forces up to 40 N (9 lbf) in the normal direction and 22 N (5 lbf) in the shear direction with an accuracy of +/- 0.04 N (+/- 0.01 lbf) Since high resolution is required for the force measurement, the Load Measurement System is built with highly sensitive load cells. To protect these fragile load cells in the non-operational mode from being damaged due to flight loads such as launch and landing loads of the Shuttle vehicle, a motor driven device known as the Load Cell Lock-Out Mechanism was built. This Lock-Out Mechanism isolates the load cells from flight loads and re-engages the load cells for the force measurement experiment once in space. With this highly effective protection system, the SPIFEX load measurement experiment was successfully conducted on STS-44 in September 1994 with all load cells operating properly and reading impingement forces as expected.

  1. Study of the Properties of Bentonites for their use in Clay Geo synthetic Barriers; Estudio de la propiedades de las bentonitas para su utilizacion en barreras geosinteticas arcillosas

    Energy Technology Data Exchange (ETDEWEB)

    Leiro Lopez, A.; Mateo Sanz, B.; Garcia Cidoncha, H.; Blanco Fernandez, M.

    2014-02-01

    Bentonites used for the production of clay geo synthetic barriers need to meet some properties so that they can be a waterproofing system. among the bentonites used in industry, sodium bentonite has the lowest permeability due to its high water absorption capacity in the inter-laminar space, causing it to swell and form a barrier to water flow. this paper provides the study of the properties of four bentonite to evaluate their quality the study of the properties of four bentonite to evaluate their quality. For this study, the main properties have been tested: water absorption, swelling index, fluid loss, cation exchange capacity and montmorillonite content. In order to optimize the procedure for the characterization of bentonites, correlations between different tests have been done, to identify the most suitable ones. Finally, a compatibility test has been carried out to study the performance of bentonites in water containing a high amount of sales, because in this case, an ion exchange between the interlayer sodium ions of bentonite and cations dissolved in the water can take, resulting in a decrease swell of the bentonite. (Author)

  2. Development of computer programme for the use of empirical calculation of mining subsidence; Desarrollo informatico para utilizacion de los metodos empiricos de calculo de subsidencia minera

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    The fundamental objective of the project is the elaboration of a user friendly computer programme which allows to mining technicians an easy application of the empirical calculation methods of mining subsidence. As is well known these methods use, together with a suitable theoretical support, the experimental data obtained during a long period of mining activities in areas of different geological and geomechanical nature. Thus they can incorporate to the calculus the local parameters that hardly could be taken into account by using pure theoretical methods. In general, as basic calculation method, it has been followed the procedure development by the VNIMI Institute of Leningrad, a particularly suitable method for application to the most various conditions that may occur in the mining of flat or steep seams. The computer programme has been worked out on the basis of MicroStation System (5.0 version) of INTERGRAPH which allows the development of new applications related to the basic aims of the project. An important feature, of the programme that may be quoted is the easy adaptation to local conditions by adjustment of the geomechanical or mining parameters according to the values obtained from the own working experience. (Author)

  3. Modeling, analysis and control of fuel cell hybrid power systems

    Science.gov (United States)

    Suh, Kyung Won

    Transient performance is a key characteristic of fuel cells, that is sometimes more critical than efficiency, due to the importance of accepting unpredictable electric loads. To fulfill the transient requirement in vehicle propulsion and portable fuel cell applications, a fuel cell stack is typically coupled with a battery through a DC/DC converter to form a hybrid power system. Although many power management strategies already exist, they all rely on low level controllers that realize the power split. In this dissertation we design controllers that realize various power split strategies by directly manipulating physical actuators (low level commands). We maintain the causality of the electric dynamics (voltage and current) and investigate how the electric architecture affects the hybridization level and the power management. We first establish the performance limitations associated with a stand-alone and power-autonomous fuel cell system that is not supplemented by an additional energy storage and powers all its auxiliary components by itself. Specifically, we examine the transient performance in fuel cell power delivery as it is limited by the air supplied by a compressor driven by the fuel cell itself. The performance limitations arise from the intrinsic coupling in the fluid and electrical domain between the compressor and the fuel cell stack. Feedforward and feedback control strategies are used to demonstrate these limitations analytically and with simulations. Experimental tests on a small commercial fuel cell auxiliary power unit (APU) confirm the dynamics and the identified limitations. The dynamics associated with the integration of a fuel cell system and a DC/DC converter is then investigated. Decentralized and fully centralized (using linear quadratic techniques) controllers are designed to regulate the power system voltage and to prevent fuel cell oxygen starvation. Regulating these two performance variables is a difficult task and requires a compromise

  4. Transport processes in biological systems: Tumoral cells and human brain

    Science.gov (United States)

    Lucia, Umberto

    2014-01-01

    The entropy generation approach has been developed for the analysis of complex systems, with particular regards to biological systems, in order to evaluate their stationary states. The entropy generation is related to the transport processes related to exergy flows. Moreover, cancer can be described as an open complex dynamic and self-organizing system. Consequently, it is used as an example useful to evaluate the different thermo-chemical quantities of the transport processes in normal and in tumoral cells systems.

  5. Multiway modeling and analysis in stem cell systems biology

    OpenAIRE

    Vandenberg Scott L; Bennett Kristin; Aguis Pheadra; Acar Evrim; Yener Bülent; Plopper George E

    2008-01-01

    Abstract Background Systems biology refers to multidisciplinary approaches designed to uncover emergent properties of biological systems. Stem cells are an attractive target for this analysis, due to their broad therapeutic potential. A central theme of systems biology is the use of computational modeling to reconstruct complex systems from a wealth of reductionist, molecular data (e.g., gene/protein expression, signal transduction activity, metabolic activity, etc.). A number of deterministi...

  6. WORKING PARK-FUEL CELL COMBINED HEAT AND POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Allan Jones

    2003-09-01

    This report covers the aims and objectives of the project which was to design, install and operate a fuel cell combined heat and power (CHP) system in Woking Park, the first fuel cell CHP system in the United Kingdom. The report also covers the benefits that were expected to accrue from the work in an understanding of the full technology procurement process (including planning, design, installation, operation and maintenance), the economic and environmental performance in comparison with both conventional UK fuel supply and conventional CHP and the commercial viability of fuel cell CHP energy supply in the new deregulated energy markets.

  7. Effect of Fuel Cell System Contaminants on the Pt Catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Christ, J.; Macomber, C. S.; O' Neill, K.; Neyerlin, K. C.; O' Leary, K. A.; Reid, R.; Lakshmanan, B.; Das, M.; Ohashi, M.; Van Zee, J. W.; Dinh, H. N.

    2012-01-01

    The cost of the balance of plant (BOP) fuel cell system has increased in importance with recent decreases in fuel cell stack cost. In order to lower the cost of the BOP system, low cost but relatively clean components must be used. Selection of these materials requires an understanding of potential materials and the contaminants that evolve from them, which have been shown to affect the performance and durability of fuel cells. The present work evaluates the influence of leachable constituents from prospective materials and model compounds on the electrochemical performance of a platinum catalyst.

  8. Design of a Fuel Cell Hybrid Electric Vehicle Drive System

    OpenAIRE

    Schaltz, Erik

    2010-01-01

    Fuel cells achieve more and more attention due to their potential of replacing the traditional internal combustion engine (ICE) used in the area of transportation. In this PhD thesis a fuel cell shaft power pack (FCSPP) is designed and implemented in a small truck. The FCSPP replaces the original supply system of the truck which was powered by a lead-acid battery package. The FCSPP includes fuel storage, a fuel cell system, an energy storage device, power electronics, an electric machine, and...

  9. Evaluation of ISABELLE full cell ultra high vacuum system

    International Nuclear Information System (INIS)

    The ISABELLE Full Cell Vacuum System consisting of a 40 m long, by 8.8 cm diameter stainless steel tube pumped by seven pumping stations was assembled and processed for 10-12 Torr operation. Evaluation and testing of the system and its sub-assemblies has been completed. Detail design of system components and the determination of the conditioning process was completed. The best procedure to rough pump, leak test, vacuum bake the system, condition pumps, degas gauges, turn on ion pumps and flash sublimation pumps was established. Pressures below 2 x 10-11 Torr are now routinely achieved in normal operation of the Full Cell. This includes pump down after replacement of various components and pump down after back fill with moist unfiltered air. The techniques developed for the Full Cell will be used to build the ISABELLE Ultra High Vacuum System

  10. Global behavior of gear system using mixed cell mapping

    Institute of Scientific and Technical Information of China (English)

    SHEN; Yunwen; LIU; Mengjun; DONG; Haijun

    2004-01-01

    In some mechanical nonlinear systems, the transient motion will be undergoing a very long process and the attractor-basin boundaries are so complicated that some difficulties occur in analyzing the system global behavior. To solve this problem a mixed cell mapping method based on the point mapping and the principle of simple cell mapping is developed. The algorithm of the mixed cell mapping is studied. A dynamic model of a gear pair is established with the backlash, damping, transmission error and the time-varying stiffness taken into consideration. The global behaviors of this system are analyzed. The coexistence of the system attractors and the respective attractor-basin of each attractor with different parameters are obtained, thus laying a theoretical basis for improvement of the dynamic behaviors of gear system.

  11. Synthetic biology outside the cell: linking computational tools to cell-free systems.

    Science.gov (United States)

    Lewis, Daniel D; Villarreal, Fernando D; Wu, Fan; Tan, Cheemeng

    2014-01-01

    As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo synthetic biological systems, with only a few examples of prominent work done on predicting the dynamics of cell-free synthetic systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the development of a new generation of biomimetic systems. In this review, we explore both in vivo and in vitro models of biochemical networks with a special focus on tools that could be applied to the construction of cell-free expression systems. We believe that quantitative studies of complex cellular mechanisms and pathways in synthetic systems can yield important insights into what makes cells different from conventional chemical systems. PMID:25538941

  12. Synthetic Biology Outside the Cell: Linking Computational Tools to Cell-Free Systems

    Directory of Open Access Journals (Sweden)

    Daniel eLewis

    2014-12-01

    Full Text Available As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo systems, with only a few examples of prominent work done on predicting the dynamics of cell-free systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the development of a new generation of biomimetic systems. In this review, we explore both in vivo and in vitro models of biochemical networks with a special focus on tools that could be applied to the construction of cell-free expression systems. We believe that quantitative studies of complex cellular mechanisms and pathways in synthetic systems can yield important insights into what makes cells different from conventional chemical systems.

  13. A Cell-in-the-Loop Approach to Systems Modelling and Simulation of Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    James Marco

    2015-08-01

    Full Text Available This research is aligned with the engineering challenge of scaling-up individual battery cells into a complete energy storage system (ESS. Manufacturing tolerances, coupled with thermal gradients and the differential electrical loading of adjacent cells, can result in significant variations in the rate of cell degradation, energy distribution and ESS performance. The uncertain transition from cell to system often manifests itself in over-engineered, non-optimal ESS designs within both the transport and energy sectors. To alleviate these issues, the authors propose a novel model-based framework for cell-in-the-loop simulation (CILS in which a physical cell may be integrated within a complete model of an ESS and exercised against realistic electrical and thermal loads in real-time. This paper focuses on the electrical integration of both real and simulated cells within the CILS test environment. Validation of the CILS approach using real-world electric vehicle data is presented for an 18650 cell. The cell is integrated within a real-time simulation model of a series string of similar cells in a 4sp1 configuration. Results are presented that highlight the impact of cell variability (i.e., capacity and impedance on the energy available from the multi-cell system and the useable capacity of the physical cell.

  14. Clinical Application of Stem Cells in the Cardiovascular System

    Science.gov (United States)

    Stamm, Christof; Klose, Kristin; Choi, Yeong-Hoon

    Regenerative medicine encompasses "tissue engineering" - the in vitro fabrication of tissues and/or organs using scaffold material and viable cells - and "cell therapy" - the transplantation or manipulation of cells in diseased tissue in vivo. In the cardiovascular system, tissue engineering strategies are being pursued for the development of viable replacement blood vessels, heart valves, patch material, cardiac pacemakers and contractile myocardium. Anecdotal clinical applications of such vessels, valves and patches have been described, but information on systematic studies of the performance of such implants is not available, yet. Cell therapy for cardiovascular regeneration, however, has been performed in large series of patients, and numerous clinical studies have produced sometimes conflicting results. The purpose of this chapter is to summarize the clinical experience with cell therapy for diseases of the cardiovascular system, and to analyse possible factors that may influence its outcome.

  15. Solar regenerative fuel cell system for high altitude airships

    International Nuclear Information System (INIS)

    'Full text': A closed-loop regenerative fuel cell (RFC) system that serves as an energy storage device for space activities is studied through dynamic simulations. The unique nature of the closed-loop RFC makes it an ideal power system for key applications in homeland defense and earth observatory systems such as high altitude aircrafts /airships, unmanned aerial vehicles, and in planetary exploration for flyer or for surface power. The RFC considered using the photovoltaic cells to produce electric power during the day, part of which is used to produce hydrogen and oxygen through electrolysis. The stored hydrogen and oxygen is used through a fuel cell to produce electric power during night hours. A MATLAB/SIMULINK model was developed for the components of the RFC that include a fuel cell, electrolyzer, photovoltaic solar array, power bus, humidifiers, compressor/motor assembly, expander, pumps, phase separators, storage tanks for hydrogen, oxygen and water, control valves and piping, electric grid system and controls. A proton exchange membrane (PEM) fuel cell and PEM electrolyzer were modeled in detail that included the mass momentum, energy, chemical reaction rates at cathode and anode. The PEM fuel cell voltage was modeled accounting cell activation and ohmic polarizations. A modular approach was used to develop models for each component. Component models were based on fundamental physics to the extent practical. Steady state and dynamic response of the RFC for different operational conditions including start-up, shut down, load changes and (accidental) transients was studied. (author)

  16. Establishment and utilization of radiological protection programs for the transport of radioactive material; Establecimiento y utilizacion de programas de proteccion radiologica para el transporte de material radiactivo

    Energy Technology Data Exchange (ETDEWEB)

    Lopez V, J.; Capadona, N. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250 (1429) Buenos Aires, (Argentina)]. e-mail: jlvietri@sede.arn.gov.ar

    2006-07-01

    The present work has by objective to indicate rules for the establishment and the use of the Radiological Protection Programs (PPR) that are of application to the transport of radioactive materials according to that required by the Transport Regulation of the International Atomic Energy Agency (IAEA). The PPR are established and applied in systematic form for remittent, transport and addressees, to consider the measures of radiological protection and its appropriately control during the transport stages of radioactive material. In particular, in the work it is analyzed the PPR applied to the operative stage, in the one that can be considered as one of the more important documents to use since it summarizes the evaluations and the necessary controls of radiological protection. Also it is analyzed the importance that this document gets ready on the base that it converges in the the analyses, evaluations and data that have been kept in mind during the previous stages of design of bundles and production of packings, the types and quantities of involved bundles, as well as of considering the quantities of expeditions and its frequencies, the ways of transport, etc. It is included a brief description of the parts that the PPR conforms on the base of that suggested in the advanced draft of the TS-G-1.5 Guide 'Radiation Protection Programmes for Transport of Radioactive Material', of October, 2005, of the IAEA: objectives. necessity, scope, basic elements of a PPR in function of the occupational dose. assignment of functions and responsibilities for the establishment of a PPR, evaluation and dose optimization, surface contamination, segregation and other protection measures, responses in emergencies. training and administration systems for baled and transport of radioactive material. Next an example of PPR for the transport of bundles of the A Type by lorry with content of radiopharmaceuticals that are the bundles more used worldwide in the expeditions of

  17. An electrochemical surface plasmon resonance imaging system targeting cell analysis

    Science.gov (United States)

    Zhang, L. L.; Chen, X.; Wei, H. T.; Li, H.; Sun, J. H.; Cai, H. Y.; Chen, J. L.; Cui, D. F.

    2013-08-01

    This paper presents an electrochemical-surface plasmon resonance imaging (EC-SPRI) system, enabling the characterization of optical and electrical properties of cells, simultaneously. The developed surface plasmon resonance (SPR) imaging system was capable of imaging micro cavities with a dimension of 10 μm × 10 μm and differentiated glycerol solutions with a group of refractive indices (RIs). Furthermore, the EC-SPRI system was used to image A549 cells, suggesting corresponding RI and morphology changes during the cell death process. In the end, electrochemical and SPR methods were used in combination, recording oxidation peaks of A549 cells in the cyclic voltage curves and SPR response unit increase, simultaneously.

  18. PEM fuel cell systems performance optimisation using the mathematical modeling

    International Nuclear Information System (INIS)

    PEM fuel cell systems and technologies have emerged as viable energy conversion devices for terrestrial applications (stationary and mobile). They offer huge economical and environmental potentials in the next generation power systems, but they are still more expensive than most conventional power conversion devices. Therefore, there is a need to optimize these technologies from the performance and costs point of view. Mathematical modeling proved to be the most important tool for PEM fuel cell optimization, providing the best solution for design, operating condition, experimentation and exploitation. This paper proposes a study for fluid flow channels optimization in order to improve the performance of PEM fuel cell systems. Thus, we run simulations using 3 types of geometries for the flowing channels: serpentine, parallel and spiral channel in order to find the optimum flowing geometry. Concluding, we can consider the modeling like an important alternative for fuel cell optimization and for exploitation/experimentation costs reduction. (authors)

  19. Direct methanol fuel cell and system

    Science.gov (United States)

    Wilson, Mahlon S.

    2004-10-26

    A fuel cell having an anode and a cathode and a polymer electrolyte membrane located between anode and cathode gas diffusion backings uses a methanol vapor fuel supply. A permeable polymer electrolyte membrane having a permeability effective to sustain a carbon dioxide flux equivalent to at least 10 mA/cm.sup.2 provides for removal of carbon dioxide produced at the anode by reaction of methanol with water. Another aspect of the present invention includes a superabsorpent polymer material placed in proximity to the anode gas diffusion backing to hold liquid methanol or liquid methanol solution without wetting the anode gas diffusion backing so that methanol vapor from the liquid methanol or liquid methanol-water solution is supplied to the membrane.

  20. A portable power system using PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Long, E. [Ball Aerospace and Technologies Corp., Boulder, CO (United States)

    1997-12-31

    Ball has developed a proof-of-concept, small, lightweight, portable power system. The power system uses a proton exchange membrane (PEM) fuel cell stack, stored hydrogen, and atmospheric oxygen as the oxidant to generate electrical power. Electronics monitor the system performance to control cooling air and oxidant flow, and automatically do corrective measures to maintain performance. With the controller monitoring the system health, the system can operate in an ambient environment from 0 C to +50 C. The paper describes system testing, including load testing, thermal and humidity testing, vibration and shock testing, field testing, destructive testing of high-pressure gas tanks, and test results on the fuel cell power system, metal hydride hydrogen storage, high-pressure hydrogen gas storage, and chemical hydride hydrogen storage.

  1. Fuel quality issues in stationary fuel cell systems.

    Energy Technology Data Exchange (ETDEWEB)

    Papadias, D.; Ahmed, S.; Kumar, R. (Chemical Sciences and Engineering Division)

    2012-02-07

    Fuel cell systems are being deployed in stationary applications for the generation of electricity, heat, and hydrogen. These systems use a variety of fuel cell types, ranging from the low temperature polymer electrolyte fuel cell (PEFC) to the high temperature solid oxide fuel cell (SOFC). Depending on the application and location, these systems are being designed to operate on reformate or syngas produced from various fuels that include natural gas, biogas, coal gas, etc. All of these fuels contain species that can potentially damage the fuel cell anode or other unit operations and processes that precede the fuel cell stack. These detrimental effects include loss in performance or durability, and attenuating these effects requires additional components to reduce the impurity concentrations to tolerable levels, if not eliminate the impurity entirely. These impurity management components increase the complexity of the fuel cell system, and they add to the system's capital and operating costs (such as regeneration, replacement and disposal of spent material and maintenance). This project reviewed the public domain information available on the impurities encountered in stationary fuel cell systems, and the effects of the impurities on the fuel cells. A database has been set up that classifies the impurities, especially in renewable fuels, such as landfill gas and anaerobic digester gas. It documents the known deleterious effects on fuel cells, and the maximum allowable concentrations of select impurities suggested by manufacturers and researchers. The literature review helped to identify the impurity removal strategies that are available, and their effectiveness, capacity, and cost. A generic model of a stationary fuel-cell based power plant operating on digester and landfill gas has been developed; it includes a gas processing unit, followed by a fuel cell system. The model includes the key impurity removal steps to enable predictions of impurity breakthrough

  2. Automotive Fuel Processor Development and Demonstration with Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nuvera Fuel Cells

    2005-04-15

    The potential for fuel cell systems to improve energy efficiency and reduce emissions over conventional power systems has generated significant interest in fuel cell technologies. While fuel cells are being investigated for use in many applications such as stationary power generation and small portable devices, transportation applications present some unique challenges for fuel cell technology. Due to their lower operating temperature and non-brittle materials, most transportation work is focusing on fuel cells using proton exchange membrane (PEM) technology. Since PEM fuel cells are fueled by hydrogen, major obstacles to their widespread use are the lack of an available hydrogen fueling infrastructure and hydrogen's relatively low energy storage density, which leads to a much lower driving range than conventional vehicles. One potential solution to the hydrogen infrastructure and storage density issues is to convert a conventional fuel such as gasoline into hydrogen onboard the vehicle using a fuel processor. Figure 2 shows that gasoline stores roughly 7 times more energy per volume than pressurized hydrogen gas at 700 bar and 4 times more than liquid hydrogen. If integrated properly, the fuel processor/fuel cell system would also be more efficient than traditional engines and would give a fuel economy benefit while hydrogen storage and distribution issues are being investigated. Widespread implementation of fuel processor/fuel cell systems requires improvements in several aspects of the technology, including size, startup time, transient response time, and cost. In addition, the ability to operate on a number of hydrocarbon fuels that are available through the existing infrastructure is a key enabler for commercializing these systems. In this program, Nuvera Fuel Cells collaborated with the Department of Energy (DOE) to develop efficient, low-emission, multi-fuel processors for transportation applications. Nuvera's focus was on (1) developing fuel

  3. System-level modeling and simulation of the cell culture microfluidic biochip ProCell

    OpenAIRE

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan; Hemmingsen, Mette; Dufva, Martin

    2010-01-01

    Microfluidic biochips offer a promising alternative to a conventional biochemical laboratory. There are two technologies for the microfluidic biochips: droplet-based and flow-based. In this paper we are interested in flow-based microfluidic biochips, where the liquid flows continuously through pre-defined micro-channels using valves and pumps. We present an approach to the system-level modeling and simulation of a cell culture microfluidic biochip called ProCell, Programmable Cell Culture Chi...

  4. Ultrahigh vacuum system for ISABELLE full cell

    International Nuclear Information System (INIS)

    A vacuum system consisting of a 40 m long 8.8-cm-diam stainless steel tube, pumped by seven pumping stations, has been assembled using automatic welding methods. All components have been fired at 9500C in a vacuum furnace at a pressure -4Torr. Each pumping station contains a Ti-sublimator, a 20 1/s ion pump and a UHV gauge. After assembly, the entire system was baked out at 2500C for 24 h. A pressure -11Torr was reached after titanium flash. In this paper we will discuss: (a) surface treatment of stainless for 10-11 Torr operation, (b) bake out and conditioning cycle to read 1 x 10-11 Torr, and (c) leak checking at low pressures

  5. B-lymphocyte lineage cells and the respiratory system.

    Science.gov (United States)

    Kato, Atsushi; Hulse, Kathryn E; Tan, Bruce K; Schleimer, Robert P

    2013-04-01

    Adaptive humoral immune responses in the airways are mediated by B cells and plasma cells that express highly evolved and specific receptors and produce immunoglobulins of most isotypes. In some cases, such as autoimmune diseases or inflammatory diseases caused by excessive exposure to foreign antigens, these same immune cells can cause disease by virtue of overly vigorous responses. This review discusses the generation, differentiation, signaling, activation, and recruitment pathways of B cells and plasma cells, with special emphasis on unique characteristics of subsets of these cells functioning within the respiratory system. The primary sensitization events that generate B cells responsible for effector responses throughout the airways usually occur in the upper airways, tonsils, and adenoid structures that make up the Waldeyer ring. On secondary exposure to antigen in the airways, antigen-processing dendritic cells migrate into secondary lymphoid organs, such as lymph nodes, that drain the upper and lower airways, and further B-cell expansion takes place at those sites. Antigen exposure in the upper or lower airways can also drive expansion of B-lineage cells in the airway mucosal tissue and lead to the formation of inducible lymphoid follicles or aggregates that can mediate local immunity or disease. PMID:23540615

  6. B lymphocyte lineage cells and the respiratory system

    Science.gov (United States)

    Kato, Atsushi; Hulse, Kathryn E.; Tan, Bruce K.; Schleimer, Robert P.

    2013-01-01

    Adaptive humoral immune responses in the airways are mediated by B cells and plasma cells that express highly evolved and specific receptors and produce immunoglobulins of most isotypes. In some cases, such as autoimmune diseases or inflammatory diseases caused by excessive exposure to foreign antigens, these same immune cells can cause disease by virtue of overly vigorous responses. This review discusses the generation, differentiation, signaling, activation and recruitment pathways of B cells and plasma cells, with special emphasis on unique characteristics of subsets of these cells functioning within the respiratory system. The primary sensitization events that generate B cells responsible for effector responses throughout the airways usually occur in the upper airways, in tonsils and adenoid structures that make up Waldeyer’s Ring. Upon secondary exposure to antigen in the airways, antigen-processing dendritic cells migrate into secondary lymphoid organs such as lymph nodes that drain the upper and lower airways and further B cell expansion takes place at those sites. Antigen exposure in the upper or lower airways can also drive expansion of B lineage cells in the airway mucosal tissue and lead to the formation of inducible lymphoid follicles or aggregates that can mediate local immunity or disease. PMID:23540615

  7. Cell culture monitoring by impedance mapping using a multielectrode scanning impedance spectroscopy system (CellMap)

    International Nuclear Information System (INIS)

    We report on the impedance mapping of in vitro cellular morphology by electrical impedance spectroscopy, using microelectrodes. A micro multielectrode system was designed, fabricated, assembled, tested and demonstrated for the monitoring of anchorage-dependent cell behavior and morphology. This system allowed continuous, label-free, quantitative monitoring and visualization of cell adhesion, spreading, proliferation and detachment due to cell cycle processes as well as cell–drug interaction, with spatio-temporal resolution. OvCa429 ovarian cancer cells were monitored in vitro over a period of 70 hours by inoculating the cell suspension directly on the multielectrode device. The phase angle of impedance was observed to develop a distinctive shape as a result of cell attachment and proliferation. The shape of the phase angle curve reverted back to the pre-attachment shape upon detachment of cells from the substrate, caused by the addition of trypsin to the cell culture medium. The impedance data of the cell culture were then successfully modeled as a multi-parametric equivalent circuit. The model incorporated both interfacial and cell-layer impedance parameters. Upon addition of trypsin, the cell-layer parameters showed a marked decline and were eventually eliminated from the multi-parametric model, confirming the correlation of the model to the electrode–cell–electrolyte system. These experiments demonstrate the applicability of the impedance mapping technique in visualizing and quantifying physiological changes in the cell layer due to cellular processes as well as the effect of external chemical stimulus on cells (cell–drug interaction)

  8. Real space Dynamical Super Cell Approximation for interacting disordered systems

    OpenAIRE

    Moradian, Rostam

    2004-01-01

    Effective medium super-cell approximation method which is introduced for disordered systems is extended to a general case of interacting disordered systems. We found that the dynamical cluster approximation (DCA) and also the non local coherent potential approximation (NLCPA) are two simple case of this technique. Whole equations of this formalism derived by using the effective medium theory in real space.

  9. Renal cell carcinoma arising in ipsilateral duplex system.

    Science.gov (United States)

    Mohan, Harsh; Kundu, Reetu; Dalal, Usha

    2014-09-01

    Congenital anomalies of the kidney and urinary tract are common and include a wide anatomic spectrum. Duplex systems are one of the more common renal anomalies, with the majority being asymptomatic. Little is known about the molecular pathogenesis of these anomalies; however, certain causative genes have been implicated. The finding of renal cell carcinoma arising in a kidney with the duplication of pelvicalyceal system and ureters, as in the present case, is uncommon. The association between a duplex system and renal cell carcinoma may be more than a coincidence, requiring a deeper insight and further elucidation. PMID:26328175

  10. Physics of cell adhesion: some lessons from cell-mimetic systems

    Science.gov (United States)

    Sackmann, Erich; Smith, Ana-Sunčana

    2014-01-01

    Cell adhesion is a paradigm of the ubiquitous interplay of cell signalling, modulation of material properties and biological functions of cells. It is controlled by competition of short range attractive forces, medium range repellant forces and the elastic stresses associated with local and global deformation of the composite cell envelopes. We review the basic physical rules governing the physics of cell adhesion learned by studying cell-mimetic systems and demonstrate the importance of these rules in the context of cellular systems. We review how adhesion induced micro-domains couple to the intracellular actin and microtubule networks allowing cells to generate strong forces with a minimum of attractive cell adhesion molecules (CAMs) and to manipulate other cells through filopodia over micrometer distances. The adhesion strength can be adapted to external force fluctuations within seconds by varying the density of attractive and repellant CAMs through exocytosis and endocytosis or protease-mediated dismantling of the CAM–cytoskeleton link. Adhesion domains form local end global biochemical reaction centres enabling the control of enzymes. Actin–microtubule crosstalk at adhesion foci facilitates the mechanical stabilization of polarized cell shapes. Axon growth in tissue is guided by attractive and repulsive clues controlled by antagonistic signalling pathways. PMID:24651316

  11. The thioredoxin system in breast cancer cell invasion and migration.

    Science.gov (United States)

    Bhatia, Maneet; McGrath, Kelly L; Di Trapani, Giovanna; Charoentong, Pornpimol; Shah, Fenil; King, Mallory M; Clarke, Frank M; Tonissen, Kathryn F

    2016-08-01

    Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration. PMID:26760912

  12. The thioredoxin system in breast cancer cell invasion and migration

    Directory of Open Access Journals (Sweden)

    Maneet Bhatia

    2016-08-01

    Full Text Available Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1 in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1 expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration.

  13. Stem cell-derived systems in toxicology assessment.

    Science.gov (United States)

    Suter-Dick, Laura; Alves, Paula M; Blaauboer, Bas J; Bremm, Klaus-Dieter; Brito, Catarina; Coecke, Sandra; Flick, Burkhard; Fowler, Paul; Hescheler, Jürgen; Ingelman-Sundberg, Magnus; Jennings, Paul; Kelm, Jens M; Manou, Irene; Mistry, Pratibha; Moretto, Angelo; Roth, Adrian; Stedman, Donald; van de Water, Bob; Beilmann, Mario

    2015-06-01

    Industrial sectors perform toxicological assessments of their potential products to ensure human safety and to fulfill regulatory requirements. These assessments often involve animal testing, but ethical, cost, and time concerns, together with a ban on it in specific sectors, make appropriate in vitro systems indispensable in toxicology. In this study, we summarize the outcome of an EPAA (European Partnership of Alternatives to Animal Testing)-organized workshop on the use of stem cell-derived (SCD) systems in toxicology, with a focus on industrial applications. SCD systems, in particular, induced pluripotent stem cell-derived, provide physiological cell culture systems of easy access and amenable to a variety of assays. They also present the opportunity to apply the vast repository of existing nonclinical data for the understanding of in vitro to in vivo translation. SCD systems from several toxicologically relevant tissues exist; they generally recapitulate many aspects of physiology and respond to toxicological and pharmacological interventions. However, focused research is necessary to accelerate implementation of SCD systems in an industrial setting and subsequent use of such systems by regulatory authorities. Research is required into the phenotypic characterization of the systems, since methods and protocols for generating terminally differentiated SCD cells are still lacking. Organotypical 3D culture systems in bioreactors and microscale tissue engineering technologies should be fostered, as they promote and maintain differentiation and support coculture systems. They need further development and validation for their successful implementation in toxicity testing in industry. Analytical measures also need to be implemented to enable compound exposure and metabolism measurements for in vitro to in vivo extrapolation. The future of SCD toxicological tests will combine advanced cell culture technologies and biokinetic measurements to support regulatory and

  14. Quantitative Analysis of AGV System in FMS Cell Layout

    OpenAIRE

    B Ramana; S. Sudhakara Reddy; B. Ramprasad

    1997-01-01

    Material handling is a specialised activity for a modern manufacturing concern. Automated guided vehicles (AGVs) are invariably used for material handling in flexible manufacturing Systems (FMSs) due to their flexibility. The quantitative analysis of an AGV system is useful for determining the material flow rates, operation times, length of delivery, length of empty move of AGV and the number of AGVs required for a typical FMS cell layout. The efficiency of the material handling system...

  15. Improving the performance of solid oxide fuel cell systems

    OpenAIRE

    Halinen, Matias

    2015-01-01

    Solid oxide fuel cell (SOFC) systems can provide power production at a high electrical efficiency and with very low emissions. Furthermore, they retain their high electrical efficiency over a wide range of output power and offer good fuel flexibility, which makes them well suited for a range of applications. Currently SOFC systems are under investigation by researchers as well as being developed by industrial manufacturers. The first commercial SOFC systems have been on the market for some...

  16. The Pathology of T Cells in Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Anselm Mak

    2014-01-01

    Full Text Available Systemic lupus erythematosus (SLE is characterized by the production of a wide array of autoantibodies. Thus, the condition was traditionally classified as a “B-cell disease”. Compelling evidence has however shown that without the assistance of the helper T lymphocytes, it is indeed difficult for the “helpless” B cells to become functional enough to trigger SLE-related inflammation. T cells have been recognized to be crucial in the pathogenicity of SLE through their capabilities to communicate with and offer enormous help to B cells for driving autoantibody production. Recently, a number of phenotypic and functional alterations which increase the propensity to trigger lupus-related inflammation have been identified in lupus T cells. Here, potential mechanisms involving alterations in T-cell receptor expressions, postreceptor downstream signalling, epigenetics, and oxidative stress which favour activation of lupus T cells will be discussed. Additionally, how regulatory CD4+, CD8+, and γδ T cells tune down lupus-related inflammation will be highlighted. Lastly, while currently available outcomes of clinical trials evaluating therapeutic agents which manipulate the T cells such as calcineurin inhibitors indicate that they are at least as efficacious and safe as conventional immunosuppressants in treating lupus glomerulonephritis, larger clinical trials are undoubtedly required to validate these as-yet favourable findings.

  17. Tolerance of yeast biofilm cells towards systemic antifungals

    DEFF Research Database (Denmark)

    Bojsen, Rasmus Kenneth

    of this thesis has been to explore the tolerance mechanisms of yeast biofilms to systemic antifungal agents and to identify the molecular target of a novel peptidomimetic with anti-biofilm activity. The genetic tractable S. cerevisiae was used as biofilm model system for the pathogenic Candida...... species in an attempt to take advantage of the molecular tools available for S. cerevisiae. Mature biofilms containing mainly growth arrested cells were shown to be tolerant to three out of four tested antifungals, while all drugs had inhibitory activity against proliferating biofilm cells, demonstrating...... physiological state of the cell and the mechanism of action of the drug, and this is independent of mode of growth. Based on these results, it can be suggested that future drug treatment strategies should focus on targeting growth arrested cells, rather than distinguishing between modes of growth. At last, we...

  18. Design of a Fuel Cell Hybrid Electric Vehicle Drive System

    DEFF Research Database (Denmark)

    Schaltz, Erik

    Fuel cells achieve more and more attention due to their potential of replacing the traditional internal combustion engine (ICE) used in the area of transportation. In this PhD thesis a fuel cell shaft power pack (FCSPP) is designed and implemented in a small truck. The FCSPP replaces the original...... supply system of the truck which was powered by a lead-acid battery package. The FCSPP includes fuel storage, a fuel cell system, an energy storage device, power electronics, an electric machine, and the necessary control. The FCSPP therefore converts the energy of the fuel to a shaft torque and speed of...... increase the efficiency. In this work a lead-acid battery, an ultracapacitor, or a combination of both are considered as energy storage devices. A FCSPP is designed for 10 different configurations of connecting the energy storage device(s) and fuel cell to a common bus, which comply with the 42V Power...

  19. T cells fail to develop in the human skin-cell explants system; an inconvenient truth

    Directory of Open Access Journals (Sweden)

    Vanderlocht Joris

    2011-02-01

    Full Text Available Abstract Background Haplo-identical hematopoietic stem cell (HSC transplantation is very successful in eradicating haematological tumours, but the long post-transplant T-lymphopenic phase is responsible for high morbidity and mortality rates. Clark et al. have described a skin-explant system capable of producing host-tolerant donor-HSC derived T-cells. Because this T-cell production platform has the potential to replenish the T-cell levels following transplantation, we set out to validate the skin-explant system. Results Following the published procedures, while using the same commercial components, it was impossible to reproduce the skin-explant conditions required for HSC differentiation towards mature T-cells. The keratinocyte maturation procedure resulted in fragile cells with minimum expression of delta-like ligand (DLL. In most experiments the generated cells failed to adhere to carriers or were quickly outcompeted by fibroblasts. Consequently it was not possible to reproduce cell-culture conditions required for HSC differentiation into functional T-cells. Using cell-lines over-expressing DLL, we showed that the antibodies used by Clark et al. were unable to detect native DLL, but instead stained 7AAD+ cells. Therefore, it is unlikely that the observed T-lineage commitment from HSC is mediated by DLL expressed on keratinocytes. In addition, we did confirm expression of the Notch-ligand Jagged-1 by keratinocytes. Conclusions Currently, and unfortunately, it remains difficult to explain the development or growth of T-cells described by Clark et al., but for the fate of patients suffering from lymphopenia it is essential to both reproduce and understand how these co-cultures really "work". Fortunately, alternative procedures to speed-up T-cell reconstitution are being established and validated and may become available for patients in the near future.

  20. System and method for detecting cells or components thereof

    Science.gov (United States)

    Porter, Marc D.; Lipert, Robert J.; Doyle, Robert T.; Grubisha, Desiree S.; Rahman, Salma

    2009-01-06

    A system and method for detecting a detectably labeled cell or component thereof in a sample comprising one or more cells or components thereof, at least one cell or component thereof of which is detectably labeled with at least two detectable labels. In one embodiment, the method comprises: (i) introducing the sample into one or more flow cells of a flow cytometer, (ii) irradiating the sample with one or more light sources that are absorbed by the at least two detectable labels, the absorption of which is to be detected, and (iii) detecting simultaneously the absorption of light by the at least two detectable labels on the detectably labeled cell or component thereof with an array of photomultiplier tubes, which are operably linked to two or more filters that selectively transmit detectable emissions from the at least two detectable labels.

  1. A Multimedia Offline Cell Phone System For English Language Learning

    OpenAIRE

    Osama Salameh

    2011-01-01

    Among mobile computing devices, cell phones are the most wide spread devices and are available in the hands ofalmost every university student. Other than being portable phones, many are equipped with functionalities including internetaccess, mp3/mp4 player, digital camera video recorder etc. and can run multimedia content. These features make themattractive as educational tools as well. In this paper we present an offline Flash-based prototype system for English languagelearning using cell ph...

  2. Life cycle assessment of hydrogen production and fuel cell systems

    International Nuclear Information System (INIS)

    This paper details life cycle assessment (LCA) of hydrogen production and fuel cell system. LCA is a key tool in hydrogen and fuel cell technologies for design, analysis, development; manufacture, applications etc. Energy efficiencies and greenhouse gases and air pollution emissions have been evaluated in all process steps including crude oil and natural gas pipeline transportation, crude oil distillation, natural gas reprocessing, wind and solar electricity generation , hydrogen production through water electrolysis and gasoline and hydrogen distribution and utilization

  3. Transdifferentiation of human amniotic epithelial cells into acinar cells using a double-chamber system.

    Science.gov (United States)

    Huang, Gui-Lin; Zhang, Ni-Ni; Wang, Jun-Sheng; Yao, Li; Zhao, Yu-Jie; Wang, Yu-Ying

    2012-08-01

    This study investigated the transdifferentiation of stem cells from human amnion tissue into functional acinar cells (ACs) using a co-culture system. Human amniotic epithelial cells (hAECs) were isolated from amnion tissue by mechanical mincing and enzymatic digestion. After primary culture, the phenotype of the cells was identified by flow cytometry (FCM) and immunocytochemical staining. hAECs were co-cultured with submandibular gland acinar cells of SD rats using a double-chamber system. The expression of α-amylase was determined by immunocytochemical method and fluorescent real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) after induction for 1 and 2 weeks, respectively. Digestion with trypsin is an effective method for isolating hAECs from amnion tissue. These cells were positive for CD29 and CK19 and weakly positive for CD44 and α-amylase. Within 2 weeks, α-amylase in hAECs increased with induction time. The expression of α-amylase in hAECs was increased 3.38-fold after co-culturing for 1 week. This ratio increased to 6.6-fold, and these cells were positive for mucins, after co-culturing for 2 weeks. hAECs possess the potential to differentiate into ACs in vitro. They might be a stem cell resource for clinical applications of cell replacement therapy in salivary gland dysfunction diseases. PMID:22800093

  4. Non-disruptive measurement system of cell viability in bioreactors

    Science.gov (United States)

    Rudek, F.; Nelsen, B. L.; Baselt, T.; Berger, T.; Wiele, M.; Prade, I.; Hartmann, P.

    2016-04-01

    Nutrient and oxygen transport, as well as the removal of metabolic waste are essential processes to support and maintain viable tissue. Current bioreactor technology used to grow tissue cultures in vitro has a fundamental limit to the thickness of tissues. Based on the low diffusion limit of oxygen a maximum tissue thickness of 200 μm is possible. The efficiency of those systems is currently under investigation. During the cultivation process of the artificial tissue in bioreactors, which lasts 28 days or longer, there are no possibilities to investigate the viability of cells. This work is designed to determine the influence of a non-disruptive cell viability measuring system on cellular activity. The measuring system uses a natural cellular marker produced during normal metabolic activity. Nicotinamide adenine dinucleotide (NADH) is a coenzyme naturally consumed and produced during cellular metabolic processes and has thoroughly been studied to determine the metabolic state of a cell. Measuring the fluorescence of NADH within the cell represents a non-disruptive marker for cell viability. Since the measurement process is optical in nature, NADH fluorescence also provides a pathway for sampling at different measurement depths within a given tissue sample. The measurement system we are using utilizes a special UV light source, to excite the NADH fluorescence state. However, the high energy potentially alters or harms the cells. To investigate the influence of the excitation signal, the cells were irradiated with a laser operating at a wavelength of 355 nm and examined for cytotoxic effects. The aim of this study was to develop a non-cytotoxic system that is applicable for large-scale operations during drug-tissue interaction testing.

  5. Systems Level Modeling of the Cell Cycle Using Budding Yeast

    Directory of Open Access Journals (Sweden)

    D.R. Kim

    2007-01-01

    Full Text Available Proteins involved in the regulation of the cell cycle are highly conserved across all eukaryotes, and so a relatively simple eukaryote such as yeast can provide insight into a variety of cell cycle perturbations including those that occur in human cancer. To date, the budding yeast Saccharomyces cerevisiae has provided the largest amount of experimental and modeling data on the progression of the cell cycle, making it a logical choice for in-depth studies of this process. Moreover, the advent of methods for collection of high-throughput genome, transcriptome, and proteome data has provided a means to collect and precisely quantify simultaneous cell cycle gene transcript and protein levels, permitting modeling of the cell cycle on the systems level. With the appropriate mathematical framework and suffi cient and accurate data on cell cycle components, it should be possible to create a model of the cell cycle that not only effectively describes its operation, but can also predict responses to perturbations such as variation in protein levels and responses to external stimuli including targeted inhibition by drugs. In this review, we summarize existing data on the yeast cell cycle, proteomics technologies for quantifying cell cycle proteins, and the mathematical frameworks that can integrate this data into representative and effective models. Systems level modeling of the cell cycle will require the integration of high-quality data with the appropriate mathematical framework, which can currently be attained through the combination of dynamic modeling based on proteomics data and using yeast as a model organism.

  6. Potential of Reversible Solid Oxide Cells as Electricity Storage System

    Directory of Open Access Journals (Sweden)

    Paolo Di Giorgio

    2016-08-01

    Full Text Available Electrical energy storage (EES systems allow shifting the time of electric power generation from that of consumption, and they are expected to play a major role in future electric grids where the share of intermittent renewable energy systems (RES, and especially solar and wind power plants, is planned to increase. No commercially available technology complies with all the required specifications for an efficient and reliable EES system. Reversible solid oxide cells (ReSOC working in both fuel cell and electrolysis modes could be a cost effective and highly efficient EES, but are not yet ready for the market. In fact, using the system in fuel cell mode produces high temperature heat that can be recovered during electrolysis, when a heat source is necessary. Before ReSOCs can be used as EES systems, many problems have to be solved. This paper presents a new ReSOC concept, where the thermal energy produced during fuel cell mode is stored as sensible or latent heat, respectively, in a high density and high specific heat material and in a phase change material (PCM and used during electrolysis operation. The study of two different storage concepts is performed using a lumped parameters ReSOC stack model coupled with a suitable balance of plant. The optimal roundtrip efficiency calculated for both of the configurations studied is not far from 70% and results from a trade-off between the stack roundtrip efficiency and the energy consumed by the auxiliary power systems.

  7. Temperature dependence of photovoltaic cells, modules, and systems

    Energy Technology Data Exchange (ETDEWEB)

    Emery, K.; Burdick, J.; Caiyem, Y. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    Photovoltaic (PV) cells and modules are often rated in terms of a set of standard reporting conditions defined by a temperature, spectral irradiance, and total irradiance. Because PV devices operates over a wide range of temperatures and irradiances, the temperature and irradiance related behavior must be known. This paper surveys the temperature dependence of crystalline and thin-film, state-of-the-art, research-size cells, modules, and systems measured by a variety of methods. The various error sources and measurement methods that contribute to cause differences in the temperature coefficient for a given cell or module measured with various methods are discussed.

  8. Speech recognition systems on the Cell Broadband Engine

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y; Jones, H; Vaidya, S; Perrone, M; Tydlitat, B; Nanda, A

    2007-04-20

    In this paper we describe our design, implementation, and first results of a prototype connected-phoneme-based speech recognition system on the Cell Broadband Engine{trademark} (Cell/B.E.). Automatic speech recognition decodes speech samples into plain text (other representations are possible) and must process samples at real-time rates. Fortunately, the computational tasks involved in this pipeline are highly data-parallel and can receive significant hardware acceleration from vector-streaming architectures such as the Cell/B.E. Identifying and exploiting these parallelism opportunities is challenging, but also critical to improving system performance. We observed, from our initial performance timings, that a single Cell/B.E. processor can recognize speech from thousands of simultaneous voice channels in real time--a channel density that is orders-of-magnitude greater than the capacity of existing software speech recognizers based on CPUs (central processing units). This result emphasizes the potential for Cell/B.E.-based speech recognition and will likely lead to the future development of production speech systems using Cell/B.E. clusters.

  9. Tensegrity I. Cell structure and hierarchical systems biology

    Science.gov (United States)

    Ingber, Donald E.

    2003-01-01

    In 1993, a Commentary in this journal described how a simple mechanical model of cell structure based on tensegrity architecture can help to explain how cell shape, movement and cytoskeletal mechanics are controlled, as well as how cells sense and respond to mechanical forces (J. Cell Sci. 104, 613-627). The cellular tensegrity model can now be revisited and placed in context of new advances in our understanding of cell structure, biological networks and mechanoregulation that have been made over the past decade. Recent work provides strong evidence to support the use of tensegrity by cells, and mathematical formulations of the model predict many aspects of cell behavior. In addition, development of the tensegrity theory and its translation into mathematical terms are beginning to allow us to define the relationship between mechanics and biochemistry at the molecular level and to attack the larger problem of biological complexity. Part I of this two-part article covers the evidence for cellular tensegrity at the molecular level and describes how this building system may provide a structural basis for the hierarchical organization of living systems--from molecule to organism. Part II, which focuses on how these structural networks influence information processing networks, appears in the next issue.

  10. Synthesis of Evolving Cells for Reconfigurable Manufacturing Systems

    Science.gov (United States)

    Padayachee, J.; Bright, G.

    2014-07-01

    The concept of Reconfigurable Manufacturing Systems (RMSs) was formulated due to the global necessity for production systems that are able to economically evolve according to changes in markets and products. Technologies and design methods are under development to enable RMSs to exhibit transformable system layouts, reconfigurable processes, cells and machines. Existing factory design methods and software have not yet advanced to include reconfigurable manufacturing concepts. This paper presents the underlying group technology framework for the design of manufacturing cells that are able to evolve according to a changing product mix by mechanisms of reconfiguration. The framework is based on a Norton- Bass forecast and time variant BOM models. An adaptation of legacy group technology methods is presented for the synthesis of evolving cells and two optimization problems are presented within this context.

  11. Control of Cell Fate in the Circulatory and Ventilatory Systems

    CERN Document Server

    Thiriet, Marc

    2012-01-01

    The volumes in this authoritative series present a multidisciplinary approach to modeling and simulation of flows in the cardiovascular and ventilatory systems, especially multiscale modeling and coupled simulations. The cardiovascular and respiratory systems are tightly coupled, as their primary function is to supply oxygen to and remove carbon dioxide from the body's cells. Because physiological conduits have deformable and reactive walls, macroscopic flow behavior and prediction must be coupled to nano- and microscopic events in a corrector scheme of regulated mechanisms. Therefore, investigation of flows of blood and air in physiological conduits requires an understanding of the biology, chemistry, and physics of these systems together with the mathematical tools to describe their functioning. Volumes 1 and 2 are devoted to cell organization and fate, as well as activities that are autoregulated and/or controlled by the cell environment. Volume 1 examined cellular features that allow adaptation to env...

  12. Systemic lupus erythematosus in patients with sickle cell disease.

    Science.gov (United States)

    Appenzeller, Simone; Fattori, Andre; Saad, Sarita T; Costallat, Lilian T L

    2008-03-01

    Sickle cell disease (SCD) is a prevalent genetic disorder that includes sickle cell anemia (hemoglobin SS), hemoglobin SC, and hemoglobin Sb-thalassemia. Patients with SCD present with a defective activation of the alternate pathway of the complement system that increases the risk of capsulate bacteria infection and failure to eliminate antigens, predisposing these patients to autoimmune diseases. The authors describe three patients with SCD that developed systemic lupus erythematosus (SLE). In all patients, SLE diagnosis was delayed because symptoms were initially attributable to SCD. Physicians should be alerted to the possible development of SLE in patients with SCD to not delay the diagnosis and start appropriate treatment. PMID:18000698

  13. Continuous glutamate production using an immobilized whole-cell system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.S.; Ryu, D.D.Y.

    1982-10-01

    For the purpose of saving the energy and raw materials required in a glutamate fermentation, an immobilized whole-cell system was prepared and its performance in a continuous reactor system was evaluated. Corynebacterium glutamicum (a mutant strain of ATCC 13058) whole cell was immobilized in k-carrageenan matrix and the gel structure was strengthened by treatment with a hardening agent. The effective diffusivities of carrageenan gel for glucose and oxygen were formed to decrease significantly with an increase in carrageenan concentration, while the gel strength showed an increasing trend. Based on the physical and chemical properties of carrageenan gel, the immobilized method was improved and the operation of the continuous reactor system was partially optimized. In an air-stirred fermentor, the continuous production of glutamate was carried out. The effect of the dilution rate of glutamate production and operation stability was investigated. The performance of the continuous wbole-cell reactor system was evaluated by measuring glutamate productivity for a period of 30 days; it was found to be far superior to the performance of convention batch reactor systems using free cells.

  14. Cell Monitoring and Manipulation Systems (CMMSs based on Glass Cell-Culture Chips (GC3s

    Directory of Open Access Journals (Sweden)

    Sebastian M. Buehler

    2016-06-01

    Full Text Available We developed different types of glass cell-culture chips (GC3s for culturing cells for microscopic observation in open media-containing troughs or in microfluidic structures. Platinum sensor and manipulation structures were used to monitor physiological parameters and to allocate and permeabilize cells. Electro-thermal micro pumps distributed chemical compounds in the microfluidic systems. The integrated temperature sensors showed a linear, Pt1000-like behavior. Cell adhesion and proliferation were monitored using interdigitated electrode structures (IDESs. The cell-doubling times of primary murine embryonic neuronal cells (PNCs were determined based on the IDES capacitance-peak shifts. The electrical activity of PNC networks was detected using multi-electrode arrays (MEAs. During seeding, the cells were dielectrophoretically allocated to individual MEAs to improve network structures. MEA pads with diameters of 15, 20, 25, and 35 µm were tested. After 3 weeks, the magnitudes of the determined action potentials were highest for pads of 25 µm in diameter and did not differ when the inter-pad distances were 100 or 170 µm. Using 25-µm diameter circular oxygen electrodes, the signal currents in the cell-culture media were found to range from approximately −0.08 nA (0% O2 to −2.35 nA (21% O2. It was observed that 60-nm thick silicon nitride-sensor layers were stable potentiometric pH sensors under cell-culture conditions for periods of days. Their sensitivity between pH 5 and 9 was as high as 45 mV per pH step. We concluded that sensorized GC3s are potential animal replacement systems for purposes such as toxicity pre-screening. For example, the effect of mefloquine, a medication used to treat malaria, on the electrical activity of neuronal cells was determined in this study using a GC3 system.

  15. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system

    Directory of Open Access Journals (Sweden)

    Enrique Montalvillo

    2014-05-01

    Full Text Available The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on innate lymphoid cells, a newly discovered, heterogeneous set of cells that derive from an Id2-dependent lymphoid progenitor cell population. These cells have been categorized on the basis of the pattern of cytokines that they secrete, and the transcription factors that regulate their development and functions. Innate lymphoid cells play a role in the early response to pathogens, the anatomical contention of the commensal flora, and the maintenance of epithelial integrity. Amongst the various innate lymphoid cells we shall lay emphasis on a subpopulation with several peculiarities, namely that of natural killer T cells, a subset of T lymphocytes that express both T-cell and NK-cell receptors. The most numerous fraction of the NKT population are the so-called invariant NKT or iNKT cells. These iNKT cells have an invariant TCR and recognize the glycolipidic structures presented by the CD1d molecule, a homolog of class-I MHC molecules. Following activation they rapidly acquire cytotoxic activity and secrete both Th1 and Th2 cytokines, including IL-17. While their specific role is not yet established, iNKT cells take part in a great variety of intestinal immune responses ranging from oral tolerance to involvement in a number of gastrointestinal conditions.

  16. Familial occurrence of systemic mast cell activation disease.

    Directory of Open Access Journals (Sweden)

    Gerhard J Molderings

    Full Text Available Systemic mast cell activation disease (MCAD comprises disorders characterized by an enhanced release of mast cell mediators accompanied by accumulation of dysfunctional mast cells. Demonstration of familial clustering would be an important step towards defining the genetic contribution to the risk of systemic MCAD. The present study aimed to quantify familial aggregation for MCAD and to investigate the variability of clinical and molecular findings (e.g. somatic mutations in KIT among affected family members in three selected pedigrees. Our data suggest that systemic MCAD pedigrees include more systemic MCAD cases than would be expected by chance, i.e., compared with the prevalence of MCAD in the general population. The prevalence of MCAD suspected by symptom self-report in first-degree relatives of patients with MCAD amounted to approximately 46%, compared to prevalence in the general German population of about 17% (p<0.0001. In three families with a high familial loading of MCAD, the subtype of MCAD and the severity of mediator-related symptoms varied between family members. In addition, genetic alterations detected in KIT were variable, and included mutations at position 816 of the amino acid sequence. In conclusion, our data provide evidence for common familial occurrence of MCAD. Our findings observed in the three pedigrees together with recent reports in the literature suggest that, in familial cases (i.e., in the majority of MCAD, mutated disease-related operator and/or regulator genes could be responsible for the development of somatic mutations in KIT and other proteins important for the regulation of mast cell activity. Accordingly, the immunohistochemically different subtypes of MCAD (i.e. mast cell activation syndrome and systemic mastocytosis should be more accurately regarded as varying presentations of a common generic root process of mast cell dysfunction, than as distinct diseases.

  17. A degree theory for coupled cell systems with quotient symmetries

    International Nuclear Information System (INIS)

    We introduce a topological degree theory for the study of Hopf bifurcations in coupled cell systems whose quotient systems (obtained by restricting the system to its flow-invariant subspaces) possess various symmetries. To describe the structure of these quotient symmetries, we introduce the concept of a representation lattice, which is defined as a lattice of representation spaces of (different) symmetry groups that satisfy a compatibility and a consistence condition. Based on the (twisted) equivariant degree, we define a lattice-equivariant degree for maps that are compatible with respect to this representation lattice structure. We apply the lattice-equivariant degree to study a synchrony-breaking Hopf-bifurcation problem in (homogeneous) coupled cell systems and obtain a topological classification of all bifurcating branches of oscillating solutions according to their synchrony types and their symmetric properties. (paper)

  18. Design of Propulsion System for a Fuel Cell Vehicle

    DEFF Research Database (Denmark)

    Schaltz, Erik; Andreasen, Søren Juhl; Rasmussen, Peter Omand

    2007-01-01

    This paper presents a design method of propulsion systems for fuel cell vehicles complying with the 42V PowerNet standard. The method is based on field measurements during several weeks. Several cases of combining energy storage devices to a common bus voltage are investigated, and the total mass......, volume, cost and efficiency of the propulsion system are compared. It is concluded that the number of energy storage devices and their connecting to the common bus have a significant affect of the mass, volume, cost and efficiency of the propulsion system.......This paper presents a design method of propulsion systems for fuel cell vehicles complying with the 42V PowerNet standard. The method is based on field measurements during several weeks. Several cases of combining energy storage devices to a common bus voltage are investigated, and the total mass...

  19. Synthetic Biology Outside the Cell: Linking Computational Tools to Cell-Free Systems

    OpenAIRE

    Lewis, Daniel D.; Villarreal, Fernando D.; Wu, Fan; Tan, Cheemeng

    2014-01-01

    As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo synthetic biological systems, with only a few examples of prominent work done on predicting the dynamics of cell-free synthetic systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the...

  20. Development of the large scale digital cell analysis system

    International Nuclear Information System (INIS)

    Quantitative analysis of large numbers of cells exposed to various stresses would be facilitated by an automated microscope system designed to monitor up to 1000 microscope fields over time intervals of up to one month. The Large Scale Digital Cell Analysis System (LSDCAS) was designed by the authors to provide such analysis capabilities. This report presents a description of the development of the LSDCAS and its application to the study of cells undergoing radiation-induced mitotic catastrophe. A detailed description of the data acquisition algorithms used and the hardware configuration underlying the system is presented. Quantitative analysis of colony formation of cells exposed to 5 Gy X irradiation is presented. Upon analysis, it was found that the plating efficiency in irradiated population agreed with that obtained using conventional colony-formation assays, indicating the accuracy of LSDCAS in the determination of cell clonogenicity. An unexpected finding was that fully 50% of the surviving colonies exhibited mitotic catastrophe that persisted throughout colony formation. Ongoing extension of the capabilities of the LSDCAS using image segmentation techniques applied to a variety of cellular endpoints is then briefly described. (author)

  1. Cell culture systems for the hepatitis C virus

    Institute of Scientific and Technical Information of China (English)

    Gilles Duverlie; Czeslaw Wychowski

    2007-01-01

    Since the discovery of HCV in 1989, the lack of a cell culture system has hampered research progress on this important human pathogen. No robust system has been obtained by empiric approaches, and HCV cell culture remained hypothetical until 2005. The construction of functional molecular clones has served as a starting point to reconstitute a consensus infectious cDNA that was able to transcribe infectious HCV RNAs as shown by intrahepatic inoculation in a chimpanzee. Other consensus clones have been selected and established in a human hepatoma cell line as replicons, i.e. self-replicating subgenomic or genomic viral RNAs. However, these replicons did not support production of infectious virus. Interestingly, some full-length replicons could be established without adaptive mutations and one of them was able to replicate at very high levels and to release virus particles that are infectious in cell culture and in vivo. This new cell culture system represents a major breakthrough in the HCV field and should enable a broad range of basic and applied studies to be achieved.

  2. Start-up analysis for automotive PEM fuel cell systems

    Science.gov (United States)

    De Francesco, M.; Arato, E.

    The development of fuel cell cars can play an important role in resolving transport problems, due to the high environmental compatibility and high efficiency of this kind of vehicle. Among the different types of fuel cells, proton-exchange membrane fuel cells (PEMFCs) are considered the best solution for automotive applications at the moment. In this work, constructive criteria are discussed with the aim of obtaining a power generation module adaptable to a wide range of cars. A particular problem in accomplishing the overall project is represented by the definition of the compressor system for air feeding. In this work, the design approach to the problem will be delineated: some options are reviewed and the best solution is analysed. The transient response of the system (fuel cell and compressor) is investigated in order to optimise the start-up running through a model of a fuel cell stack and a compressor simulation. The model and its results are proposed as a work procedure to solve the problem, by varying external conditions: in fact, to perform the system start-up under stable conditions, the air relative humidity and temperature must be maintained in a proper range of values. The approach here presented has been utilised for the definition of the characteristics of the power module and layout of a middle-size hybrid city bus in the framework of a project promoted by the European Union.

  3. In-silico Models of Stem Cell and Developmental Systems

    OpenAIRE

    Setty, Y.

    2014-01-01

    Understanding how developmental systems evolve over time is a key question in stem cell and developmental biology research. However, due to hurdles of existing experimental techniques, our understanding of these systems as a whole remains partial and coarse. In recent years, we have been constructing in-silico models that synthesize experimental knowledge using software engineering tools. Our approach integrates known isolated mechanisms with simplified assumptions where the knowledge is limi...

  4. Fuel Cell Assisted PhotoVoltaic Power Systems

    OpenAIRE

    Tesfahunegn, Samson Gebre

    2012-01-01

    Distributed generation (DG) systems as local power sources have great potential to contribute toward energy sustainability, energy efficiency and supply reliability. This thesis deals with DGs that use solar as primary energy input, hydrogen energy storage and conversion technologies (fuel cells and water electrolyzers) as long term backup and energy storage batteries and supercapacitors as short term backup. Standalone power systems isolated from the grid such as those used to power remote a...

  5. Langerhans cell histiocytosis involving central nervous system: a case report

    International Nuclear Information System (INIS)

    Langerhans cell histiocytosis(LCH) is a systemic disorder characterized by idiopathic proliferation of histiocytes in the reticuloendothelial system; CNS involvement outside the hypothalamus or pituitary gland is uncommon. We present a case of LCH involving the brainstem, cerebellum, and temporal lobes, and also showing hypothalamic involvement. The lesions were isointense or hypointense on T1WI and hyperintense on T2WI, and showed multifocal enhancing nodules on post-contrast CT and Gd-enhanced MRI

  6. Langerhans cell histiocytosis involving central nervous system: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Won Jin; Park, Dong Woo; Lee, Seung Ro; Hahm, Chang Kok; Ju, Kyung Bin [Hanyang University College of Medicine, Seoul (Korea, Republic of); Kim, Sung Tae [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    1997-01-01

    Langerhans cell histiocytosis(LCH) is a systemic disorder characterized by idiopathic proliferation of histiocytes in the reticuloendothelial system; CNS involvement outside the hypothalamus or pituitary gland is uncommon. We present a case of LCH involving the brainstem, cerebellum, and temporal lobes, and also showing hypothalamic involvement. The lesions were isointense or hypointense on T1WI and hyperintense on T2WI, and showed multifocal enhancing nodules on post-contrast CT and Gd-enhanced MRI.

  7. Computational Systems Biology Analysis of Cell Reprogramming and Activation Dynamics

    OpenAIRE

    Fu, Yan

    2012-01-01

    In the past two decades, molecular cell biology has transitioned from a traditional descriptive science into a quantitative science that systematically measures cellular dynamics on different levels of genome, transcriptome and proteome. Along with this transition emerges the interdisciplinary field of systems biology, which aims to unravel complex interactions in biological systems through integrating experimental data into qualitative or quantitative models and computer simulations. In th...

  8. Apoptosis and systemic autoimmunity: the dendritic cell connection

    Directory of Open Access Journals (Sweden)

    AA Manfredi

    2009-12-01

    Full Text Available Much effort has been devoted in recent years to the events linking recognition and disposal of apoptotic cells to sustained immunity towards the antigens they contain. Programmed death via apoptosis indeed provides most of the raw material the immune system exploits to establish self tolerance, i.e. to learn how to distinguish between self constituents and foreign antigens, belonging to invading pathogens. In parallel, events occurring during cell death may enable a restricted array of molecules endowed with diverse structure, function and intracellular distribution to satisfy the requirement to evoke and maintain autoimmune responses. Dendritic cells (DCs, the most potent antigen presenting cells, appear to play a crucial role. Here we will discuss some of the constrains regulating the access of dying cells’ antigens to DCs, as well as censorship mechanisms that prevent their maturation and the full explication of their antigen presenting function.

  9. State of direct fuel cell/turbine systems development

    Science.gov (United States)

    Ghezel-Ayagh, Hossein; Walzak, Jim; Patel, Dilip; Daly, Joseph; Maru, Hans; Sanderson, Robert; Livingood, William

    FuelCell Energy Inc. (FCE) is actively developing fuel cell/gas turbine hybrid systems, DFC/T ®, for generation of clean electric power with very high efficiencies. The gas turbine extends the high efficiency of the fuel cell without the need for supplementary fuel. Key features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas (60% on coal gas), minimal emissions, simple design, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. FCE successfully completed sub-MW scale proof-of-concept tests (pre-alpha DFC/T hybrid power plant). The tests demonstrated that the concept results in higher power plant efficiency. A small packaged natural gas fueled sub-MW unit is being developed for demonstrations (alpha and beta units). Also, the preliminary design of a 40 MW power plant including the key equipment layout and the site plan was completed.

  10. Fuel and control for an integrated fuel cell system

    International Nuclear Information System (INIS)

    The OS/IES (On-Site Integrated Energy System) comprises a phosphoric acid fuel cell driven total energy package that produces electrical energy in the form of AC power (when the DC voltage from the fuel cell is inverted), and heat energy in the form of hot water. The fuel cell prefers a fuel high in hydrogen therefore it becomes necessary to convert as much of the fuel, i.e. natural or pipeline gas into hydrogen as possible using a fuel reformer. Fuel reforming is an endothermic process and in this case waste energy in the form of ''spent'' fuel from the fuel cell is used to supply heat to the reformer. Fuel cell waste heat is also used to raise the steam used in the reforming process. The OS/IES fuel processing system comprises five interrelated subsystems. Each subsystem is controlled independently through a microprocessor but a change in any subsystem function could have an effect on the operation of any or several other subsystems. Thus the controller receives a signal indicating electrical demand and proceeds to balance the subsystems as well as the fuel and air flow to each of the fuel cells. The controller also responds to a number of alarm signals and is capable of starting and stopping the complete OS/IES. It is assisted by a tie to the utility line which can dispense electrical energy for startup or instantaneous load following and accept excess generated power in case of load loss. In this paper we review fuel cell operation and requirements, the components and interactions that make up the reformer system, and the microprocessor control required to integrate the OS/IES

  11. Pharmacology of cell adhesion molecules of the nervous system

    DEFF Research Database (Denmark)

    Kiryushko, Darya; Bock, Elisabeth; Berezin, Vladimir

    2007-01-01

    Cell adhesion molecules (CAMs) play a pivotal role in the development and maintenance of the nervous system under normal conditions. They also are involved in numerous pathological processes such as inflammation, degenerative disorders, and cancer, making them attractive targets for drug...

  12. Systems-biology dissection of eukaryotic cell growth

    OpenAIRE

    Andrews Justen; Przytycka Teresa M

    2010-01-01

    Abstract A recent article in BMC Biology illustrates the use of a systems-biology approach to integrate data across the transcriptome, proteome and metabolome of budding yeast in order to dissect the relationship between nutrient conditions and cell growth. See research article http://jbiol.com/content/6/2/4 and http://www.biomedcentral.com/1741-7007/8/68

  13. Stem cell autotomy and niche interaction in different systems.

    Science.gov (United States)

    Dorn, David C; Dorn, August

    2015-07-26

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon

  14. Reformed Methanol Fuel Cell Systems - and their use in Electric Hybrid Systems

    OpenAIRE

    Justesen, Kristian Kjær

    2015-01-01

    PEM fuel cells are widely regarded as a promising technology which has the potential to replace more polluting and less efficient internal combustion engines in many applications. They do, however, have the drawback that their hydrogen fuel is cumbersome and energy consuming to store and transport. Alternative system topologies that use a liquid fuel is therefore of great interest. One such topology is the Reformed Methanol Fuel Cell (RMFC) system where a mixture of liquid methanol and water ...

  15. The fuel cells: Truths on the generation of clean and efficient electricity electrochemical way; Las celdas de combustible: Verdades sobre la generacion de electricidad limpia y eficiente via electroquimica

    Energy Technology Data Exchange (ETDEWEB)

    Cano Castillo, Ulises [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    In the search of alternative technologies for the generation of electrical energy, the Instituto de Investigaciones Electricas (IIE) has put special attention in a technology that promises to be key in the next years: The fuel cells, it is for this reason that in this article a review of this type of cells is presented, as well as its basic characteristics and benefits as a result of its use for the generation of electrical energy. [Spanish] En la busqueda de tecnologias alternativas de generacion de energia electrica, el Instituto de Investigaciones Electricas (IIE) ha puesto atencion especial en una tecnologia que promete ser clave en los proximos anos: Las celdas de combustible, es por ello que en este articulo se presenta una resena de este tipo de celdas, asi como sus caracteristicas principales y beneficios como resultado de su utilizacion para la generacion de energia electrica.

  16. Multiway modeling and analysis in stem cell systems biology

    Directory of Open Access Journals (Sweden)

    Vandenberg Scott L

    2008-07-01

    Full Text Available Abstract Background Systems biology refers to multidisciplinary approaches designed to uncover emergent properties of biological systems. Stem cells are an attractive target for this analysis, due to their broad therapeutic potential. A central theme of systems biology is the use of computational modeling to reconstruct complex systems from a wealth of reductionist, molecular data (e.g., gene/protein expression, signal transduction activity, metabolic activity, etc.. A number of deterministic, probabilistic, and statistical learning models are used to understand sophisticated cellular behaviors such as protein expression during cellular differentiation and the activity of signaling networks. However, many of these models are bimodal i.e., they only consider row-column relationships. In contrast, multiway modeling techniques (also known as tensor models can analyze multimodal data, which capture much more information about complex behaviors such as cell differentiation. In particular, tensors can be very powerful tools for modeling the dynamic activity of biological networks over time. Here, we review the application of systems biology to stem cells and illustrate application of tensor analysis to model collagen-induced osteogenic differentiation of human mesenchymal stem cells. Results We applied Tucker1, Tucker3, and Parallel Factor Analysis (PARAFAC models to identify protein/gene expression patterns during extracellular matrix-induced osteogenic differentiation of human mesenchymal stem cells. In one case, we organized our data into a tensor of type protein/gene locus link × gene ontology category × osteogenic stimulant, and found that our cells expressed two distinct, stimulus-dependent sets of functionally related genes as they underwent osteogenic differentiation. In a second case, we organized DNA microarray data in a three-way tensor of gene IDs × osteogenic stimulus × replicates, and found that application of tensile strain to a

  17. Scheduling of Power System Cells Integrating Stochastic Power Generation

    International Nuclear Information System (INIS)

    Energy supply and climate change are nowadays two of the most outstanding problems which societies have to cope with under a context of increasing energy needs. Public awareness of these problems is driving political willingness to take actions for tackling them in a swift and efficient manner. Such actions mainly focus in increasing energy efficiency, in decreasing dependence on fossil fuels, and in reducing greenhouse gas emissions. In this context, power systems are undergoing important changes in the way they are planned and managed. On the one hand, vertically integrated structures are being replaced by market structures in which power systems are un-bundled. On the other, power systems that once relied on large power generation facilities are witnessing the end of these facilities' life-cycle and, consequently, their decommissioning. The role of distributed energy resources such as wind and solar power generators is becoming increasingly important in this context. However, the large-scale integration of such type of generation presents many challenges due, for instance, to the uncertainty associated to the variability of their production. Nevertheless, advanced forecasting tools may be combined with more controllable elements such as energy storage devices, gas turbines, and controllable loads to form systems that aim to reduce the impacts that may be caused by these uncertainties. This thesis addresses the management under market conditions of these types of systems that act like independent societies and which are herewith named power system cells. From the available literature, a unified view of power system scheduling problems is also proposed as a first step for managing sets of power system cells in a multi-cell management framework. Then, methodologies for performing the optimal day-ahead scheduling of single power system cells are proposed, discussed and evaluated under both a deterministic and a stochastic framework that directly integrates the

  18. Self-Regulating Water-Separator System for Fuel Cells

    Science.gov (United States)

    Vasquez, Arturo; McCurdy, Kerri; Bradley, Karla F.

    2007-01-01

    proposed system would perform multiple coordinated functions in regulating the pressure of the oxidant gas (usually, pure oxygen) flowing to a fuelcell stack and in removing excess product water that is generated in the normal fuel-cell operation. The system could function in the presence or absence of gravitation, and in any orientation in a gravitational field. Unlike some prior systems for removing product water, the proposed system would not depend on hydrophobicity or hydrophilicity of surfaces that are subject to fouling and, consequently, to gradual deterioration in performance. Also unlike some prior systems, the proposed system would not include actively controlled electric motors for pumping; instead, motive power for separation and pumping away of product water would be derived primarily from the oxidant flow and perhaps secondarily from the fuel flow. The net effect of these and other features would be to make the proposed system more reliable and safer, relative to the prior systems. The proposed system (see figure) would include a pressure regulator and sensor in the oxidant supply just upstream from an ejector reactant pump. The pressure of the oxidant supply would depend on the consumption flow. In one of two control subsystems, the pressure of oxidant flowing from the supply to the ejector would be sensed and used to control the speed of a set of a reciprocating constant-displacement pump so that the volumetric flow of nominally incompressible water away from the system would slightly exceed the rate at which water was produced by the fuel cell(s). The two-phase (gas/liquid water) outlet stream from the fuel cell(s) would enter the water separator, a turbinelike centrifugal separator machine driven primarily by the oxidant gas stream. A second control subsystem would utilize feedback derived from the compressibility of the outlet stream: As the separator was emptied of liquid water, the compressibility of the pumped stream would increase. The

  19. Cell migration in the developing rodent olfactory system.

    Science.gov (United States)

    Huilgol, Dhananjay; Tole, Shubha

    2016-07-01

    The components of the nervous system are assembled in development by the process of cell migration. Although the principles of cell migration are conserved throughout the brain, different subsystems may predominantly utilize specific migratory mechanisms, or may display unusual features during migration. Examining these subsystems offers not only the potential for insights into the development of the system, but may also help in understanding disorders arising from aberrant cell migration. The olfactory system is an ancient sensory circuit that is essential for the survival and reproduction of a species. The organization of this circuit displays many evolutionarily conserved features in vertebrates, including molecular mechanisms and complex migratory pathways. In this review, we describe the elaborate migrations that populate each component of the olfactory system in rodents and compare them with those described in the well-studied neocortex. Understanding how the components of the olfactory system are assembled will not only shed light on the etiology of olfactory and sexual disorders, but will also offer insights into how conserved migratory mechanisms may have shaped the evolution of the brain. PMID:26994098

  20. Commercial phosphoric acid fuel cell system technology development

    Science.gov (United States)

    Prokopius, P. R.; Warshay, M.; Simons, S. N.; King, R. B.

    1979-01-01

    A review of the current commercial phosphoric acid fuel cell system technology development efforts is presented. In both the electric utility and on-site integrated energy system applications, reducing cost and increasing reliability are the technology drivers at this time. The longstanding barrier to the attainment of these goals, which manifests itself in a number of ways, has been materials. The differences in approach among the three major participants (United Technologies Corporation (UTC), Westinghouse Electric Corporation/Energy Research Corporation (ERC), and Engelhard Industries) and their unique technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection and system design philosophy are discussed.

  1. Reactivation System for Proton-Exchange Membrane Fuel-Cells

    Directory of Open Access Journals (Sweden)

    Roberto Giral

    2012-07-01

    Full Text Available In recent years, Proton-Exchange Membrane Fuel Cells (PEMFCs have been the focus of very intensive researches. Manufacturers of these alternative power sources propose a rejuvenation sequence after the FC has been operating at high power for a certain period of time. These rejuvenation methods could be not appropriate for the reactivation of the FC when it has been out of operation for a long period of time or after it has been repaired. Since the developed reactivation system monitors temperature, current, and the cell voltages of the stack, it could be also useful for the diagnostic and repairing processes. The limited number of published contributions suggests that systems developing reactivation techniques are an open research field. In this paper, an automated system for reactivating PEMFCs and results of experimental testing are presented.

  2. A combined capillary cooling system for cooling fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ana Paula; Pelizza, Pablo Rodrigo; Galante, Renan Manozzo; Bazzo, Edson [Universidade Federal de Santa Catarina (LabCET/UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], Emails: ana@labcet.ufsc.br, pablo@labcet.ufsc.br, renan@labcet.ufsc.br, ebazzo@emc.ufsc.br

    2010-07-01

    The operation temperature control has an important influence over the PEMFC (Proton Exchange Membrane Fuel Cell) performance. A two-phase heat transfer system is proposed as an alternative for cooling and thermal control of PEMFC. The proposed system consists of a CPL (Capillary Pumped Loop) connected to a set of constant conductance heat pipes. In this work ceramic wick and stainless mesh wicks have been used as capillary structure of the CPL and heat pipes, respectively. Acetone has been used as the working fluid for CPL and deionized water for the heat pipes. Experimental results of three 1/4 inch stainless steel outlet diameter heats pipes and one CPL have been carried out and presented in this paper. Further experiments are planned coupling the proposed cooling system to a module which simulates the fuel cell. (author)

  3. Advanced ECU Software Development Method for Fuel Cell Systems

    Institute of Scientific and Technical Information of China (English)

    TIAN Shuo; LIU Yuan; XIA Wenchuan; LI Jianqiu; YANG Minggao

    2005-01-01

    The electronic control unit (ECU) in electrical powered hybrid and fuel cell vehicles is exceedingly complex. Rapid prototyping control is used to reduce development time and eliminate errors during software development. This paper describes a high-efficiency development method and a flexible tool chain suitable for various applications in automotive engineering. The control algorithm can be deployed directly from a Matlab/Simulink/Stateflow environment into the ECU hardware together with an OSEK real-time operating system (RTOS). The system has been successfully used to develop a 20-kW fuel cell system ECU based on a Motorola PowerPC 555 (MPC555) microcontroller. The total software development time is greatly reduced and the code quality and reliability are greatly enhanced.

  4. Monocrystalline silicon solar cells applied in photovoltaic system

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2012-07-01

    Full Text Available Purpose: The aim of the paper is to fabricate the monocrystalline silicon solar cells using the conventional technology by means of screen printing process and to make of them photovoltaic system.Design/methodology/approach: The investigation of current – voltage characteristic to determinate basic electrical properties of monocrystalline silicon solar cells were investigated under Standard Test Condition. Photovoltaic module was produced from solar cells with the largest short-circuit current, which were joined in series.Findings: This work presents a conventional technological process by means of screen printed method of monocrystalline silicon solar cells production. In order to obtain a device producing an electrical energy, solar cells were connected in a photovoltaic module. Then protected from damages by Schottky and Zener diodes.Practical implications: The module was used to build a demonstration photovoltaic system – traffic light - pedestrian crossing, which shows the practical use of widely available, renewable energy source which is the Sun.Originality/value: The key to solve ecological problems, which are effects of mass combustion of fossil fuel such as: coal and crude oil is development of renewable energy technology like photovoltaic energy.

  5. Reformed Methanol Fuel Cell Systems - and their use in Electric Hybrid Systems

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær

    PEM fuel cells are widely regarded as a promising technology which has the potential to replace more polluting and less efficient internal combustion engines in many applications. They do, however, have the drawback that their hydrogen fuel is cumbersome and energy consuming to store and transport...... state of charge (SOC) of the battery. An analysis of the power through the drivetrain shows that most of the energy loss occurs in the RMFC system and that this loss could be minimized if a more constant lower power set point is used for the fuel cell. To achieve this, a SOC control is developed that...... Adaptive Neuro-Fuzzy Inference System model of the cell voltage of an HTPEM fuel cell which is trained on an identification experiment spanning the expected operating range. The inputs of the model are the fuel cell temperature, the carbon monoxide content in the anode’s supply gas and the current density...

  6. Nonlinear observer designs for fuel cell power systems

    Science.gov (United States)

    Gorgun, Haluk

    A fuel cell is an electrochemical device that combines hydrogen and oxygen, with the aid of electro-catalysts, to produce electricity. A fuel cell consists of a negatively charged anode, a positively charged cathode and an electrolyte, which transports protons or ions. A low temperature fuel cell has an electrical potential of about 0.7 Volt when generating a current density of 300--500 mA/cm2. Practical fuel cell power systems will require a combination of several cells in series (a stack) to satisfy the voltage requirements of specific applications. Fuel cells are suitable for a potentially wide variety of applications, from stationary power generation in the range of hundreds of megawatts to portable electronics in the range of a couple of watts. Efficient operation of a fuel cell system requires advanced feedback control designs. Reliable measurements from the system are necessary to implement such designs. However, most of the commercially available sensors do not operate properly in the reformate and humidified gas streams in fuel cell systems. Sensors working varying degrees of success are too big and costly, and sensors that are potentially low cost are not reliable or do not have the required life time [28]. Observer designs would eliminate sensor needs for measurements, and make feedback control implementable. Since the fuel cell system dynamics are highly nonlinear, observer design is not an easy task. In this study we aim to develop nonlinear observer design methods applicable to fuel cell systems. In part I of the thesis we design an observer to estimate the hydrogen partial pressure in the anode channel. We treat inlet partial pressure as an unknown slowly varying parameter and develop an adaptive observer that employs a nonlinear voltage injection term. However in this design Fuel Processing System (FPS) dynamics are not modelled, and their effect on the anode dynamics are treated as plant uncertainty. In part II of the thesis we study the FPS

  7. System design impacts on optimization of the advanced radioisotope power system (ARPS) AMTEC cell

    International Nuclear Information System (INIS)

    Several NASA deep space missions require Advanced Radioisotope Power Systems (ARPS) to supply spacecraft power for various internal functions and mission instruments and experiments. AMTEC (Alkali-Metal Thermal-Electric Conversion) power conversion is the DOE-selected technology for an advanced, next- generation RPS to power these spacecraft. Advanced Modular Power Systems, Inc. (AMPS) has begun investigating the design of an AMTEC-based ARPS using the General Purpose Heat Source (GPHS) and the latest PX-5 AMTEC cell technology with refractory materials in critical components. This paper presents and discusses the system design methodology, and results of important system design tradeoffs and system design impacts on the ARPS AMTEC cell design. This work investigated dual 2-GPHS system configurations and 4-GPHS system configurations with 16 side-mounted AMTEC cells operating at beginning-of-mission (BOM) and end-of-mission (EOM) GPHS heat dissipation conditions. Current design studies indicate using a refractory material AMTEC cell with 8-BASE tubes, 5.0 inches long, and 1.75 inches diameter in the 4-GPHS system configuration is the strongest design candidate to satisfy system performance requirements

  8. Systems Biology Perspectives on Minimal and Simpler Cells

    Science.gov (United States)

    Xavier, Joana C.; Patil, Kiran Raosaheb

    2014-01-01

    SUMMARY The concept of the minimal cell has fascinated scientists for a long time, from both fundamental and applied points of view. This broad concept encompasses extreme reductions of genomes, the last universal common ancestor (LUCA), the creation of semiartificial cells, and the design of protocells and chassis cells. Here we review these different areas of research and identify common and complementary aspects of each one. We focus on systems biology, a discipline that is greatly facilitating the classical top-down and bottom-up approaches toward minimal cells. In addition, we also review the so-called middle-out approach and its contributions to the field with mathematical and computational models. Owing to the advances in genomics technologies, much of the work in this area has been centered on minimal genomes, or rather minimal gene sets, required to sustain life. Nevertheless, a fundamental expansion has been taking place in the last few years wherein the minimal gene set is viewed as a backbone of a more complex system. Complementing genomics, progress is being made in understanding the system-wide properties at the levels of the transcriptome, proteome, and metabolome. Network modeling approaches are enabling the integration of these different omics data sets toward an understanding of the complex molecular pathways connecting genotype to phenotype. We review key concepts central to the mapping and modeling of this complexity, which is at the heart of research on minimal cells. Finally, we discuss the distinction between minimizing the number of cellular components and minimizing cellular complexity, toward an improved understanding and utilization of minimal and simpler cells. PMID:25184563

  9. Epigenetics, Nervous System Tumors, and Cancer Stem Cells

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, Irfan A. [Rosyln and Leslie Goldstein Laboratory for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Institute for Brain Disorders and Neural Regeneration, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Rose F. Kennedy Center for Research on Intellectual and Developmental Disabilities, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Mehler, Mark F., E-mail: mark.mehler@einstein.yu.edu [Rosyln and Leslie Goldstein Laboratory for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Institute for Brain Disorders and Neural Regeneration, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States); Rose F. Kennedy Center for Research on Intellectual and Developmental Disabilities, Albert Einstein College of Medicine, Bronx, New York, NY 10461 (United States)

    2011-09-13

    Recent advances have begun to elucidate how epigenetic regulatory mechanisms are responsible for establishing and maintaining cell identity during development and adult life and how the disruption of these processes is, not surprisingly, one of the hallmarks of cancer. In this review, we describe the major epigenetic mechanisms (i.e., DNA methylation, histone and chromatin modification, non-coding RNA deployment, RNA editing, and nuclear reorganization) and discuss the broad spectrum of epigenetic alterations that have been uncovered in pediatric and adult nervous system tumors. We also highlight emerging evidence that suggests epigenetic deregulation is a characteristic feature of so-called cancer stem cells (CSCs), which are thought to be present in a range of nervous system tumors and responsible for tumor maintenance, progression, treatment resistance, and recurrence. We believe that better understanding how epigenetic mechanisms operate in neural cells and identifying the etiologies and consequences of epigenetic deregulation in tumor cells and CSCs, in particular, are likely to promote the development of enhanced molecular diagnostics and more targeted and effective therapeutic agents for treating recalcitrant nervous system tumors.

  10. Epigenetics, Nervous System Tumors, and Cancer Stem Cells

    International Nuclear Information System (INIS)

    Recent advances have begun to elucidate how epigenetic regulatory mechanisms are responsible for establishing and maintaining cell identity during development and adult life and how the disruption of these processes is, not surprisingly, one of the hallmarks of cancer. In this review, we describe the major epigenetic mechanisms (i.e., DNA methylation, histone and chromatin modification, non-coding RNA deployment, RNA editing, and nuclear reorganization) and discuss the broad spectrum of epigenetic alterations that have been uncovered in pediatric and adult nervous system tumors. We also highlight emerging evidence that suggests epigenetic deregulation is a characteristic feature of so-called cancer stem cells (CSCs), which are thought to be present in a range of nervous system tumors and responsible for tumor maintenance, progression, treatment resistance, and recurrence. We believe that better understanding how epigenetic mechanisms operate in neural cells and identifying the etiologies and consequences of epigenetic deregulation in tumor cells and CSCs, in particular, are likely to promote the development of enhanced molecular diagnostics and more targeted and effective therapeutic agents for treating recalcitrant nervous system tumors

  11. Electrochemical investigations on magnesium/N-halogen organic cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Udhayan, R.; Bhatt, D.P. (Central Electrochemical Research Inst., Karaikudi (India))

    1992-09-01

    This paper reports the results of the experimental studies on various magnesium/magnesium perchlorate/N-halogen organic cell systems employing a constant current discharge method. Several battery parameters, viz. internal resistance, capacity, energy density and coulombic efficiency have been calculated. High open circuit potential (around 1000 mV), open circuit voltage (2.45-2.67 V) and closed circuit voltage (2.30-2.44 V) and non-toxicity are the important and attractive features of these organic cell systems. The trend of the capacities of various magnesium cell systems with respect to the chosen N-halogen organic cathodes is obtained as follows: N,N'-dichlorodimethylhydantoin (DDH) > trichloroisocyanuric acid (TCIA) > dichloroisocyanuric acid (DCIA) > trichloro melamine (TCM). The energy densities of DDH, TCIA, DCIA and TCM based cells are found to be 798, 660, 420 and 95 Wh (kg of N-halogen organic compound){sup -1}, respectively. Cyclic voltammetric behaviour of a typical compound, viz. N,N'-dichlorodimethylhydantoin, has also been studied. (Author).

  12. Cell mechanics and immune system link up to fight infections

    Science.gov (United States)

    Ekpenyong, Andrew; Man, Si Ming; Tourlomousis, Panagiotis; Achouri, Sarra; Cammarota, Eugenia; Hughes, Katherine; Rizzo, Alessandro; Ng, Gilbert; Guck, Jochen; Bryant, Clare

    2015-03-01

    Infectious diseases, in which pathogens invade and colonize host cells, are responsible for one third of all mortality worldwide. Host cells use special proteins (immunoproteins) and other molecules to fight viral and bacterial invaders. The mechanisms by which immunoproteins enable cells to reduce bacterial loads and survive infections remain unclear. Moreover, during infections, some immunoproteins are known to alter the cytoskeleton, the structure that largely determines cellular mechanical properties. We therefore used an optical stretcher to measure the mechanical properties of primary immune cells (bone marrow derived macrophages) during bacterial infection. We found that macrophages become stiffer upon infection. Remarkably, macrophages lacking the immunoprotein, NLR-C4, lost the stiffening response to infection. This in vitro result correlates with our in vivo data whereby mice lacking NLR-C4 have more lesions and hence increased bacterial distribution and spread. Thus, the immune-protein-dependent increase in cell stiffness in response to bacterial infection (in vitro result) seems to have a functional role in the system level fight against pathogens (in vivo result). We will discuss how this functional link between cell mechanical properties and innate immunity, effected by actin polymerization, reduces the spread of infection.

  13. Impaired function of bone marrow stromal cells in systemic mastocytosis

    Directory of Open Access Journals (Sweden)

    Krisztian Nemeth

    2015-07-01

    Full Text Available Patients with systemic mastocytosis (SM have a wide variety of problems, including skeletal abnormalities. The disease results from a mutation of the stem cell receptor (c-kit in mast cells and we wondered if the function of bone marrow stromal cells (BMSCs; also known as MSCs or mesenchymal stem cells might be affected by the invasion of bone marrow by mutant mast cells. As expected, BMSCs from SM patients do not have a mutation in c-kit, but they proliferate poorly. In addition, while osteogenic differentiation of the BMSCs seems to be deficient, their adipogenic potential appears to be increased. Since the hematopoietic supportive abilities of BMSCs are also important, we also studied the engraftment in NSG mice of human CD34+ hematopoietic progenitors, after being co-cultured with BMSCs of healthy volunteers vs. BMSCs derived from patients with SM. BMSCs derived from the bone marrow of patients with SM could not support hematopoiesis to the extent that healthy BMSCs do. Finally, we performed an expression analysis and found significant differences between healthy and SM derived BMSCs in the expression of genes with a variety of functions, including the WNT signaling, ossification, and bone remodeling. We suggest that some of the symptoms associated with SM might be driven by epigenetic changes in BMSCs caused by dysfunctional mast cells in the bone marrow of the patients.

  14. PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    W.L. Lundberg; G.A. Israelson; R.R. Moritz(Rolls-Royce Allison); S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann (Consultant)

    2000-02-01

    Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

  15. SECA Coal-Based Systems - FuelCell Energy, Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Ayagh, Hossein

    2014-01-31

    The overall goal of this U.S. Department of Energy (DOE) sponsored project is the development of solid oxide fuel cell (SOFC) cell and stack technology suitable for use in highly-efficient, economically-competitive central generation power plant facilities fueled by coal synthesis gas (syngas). This program incorporates the following supporting objectives: • Reduce SOFC-based electrical power generation system cost to $700 or less (2007 dollars) for a greater than 100 MW Integrated Gasification Fuel Cell (IGFC) power plant, exclusive of coal gasification and CO2 separation subsystem costs. • Achieve an overall IGFC power plant efficiency of at least 50%, from coal (higher heating value or HHV) to AC power (exclusive of CO2 compression power requirement). • Reduce the release of CO2 to the environment in an IGFC power plant to no more than 10% of the carbon in the syngas. • Increase SOFC stack reliability to achieve a design life of greater than 40,000 hours. At the inception of the project, the efforts were focused on research, design and testing of prototype planar SOFC power generators for stationary applications. FuelCell Energy, Inc. successfully completed the initial stage of the project by meeting the program metrics, culminating in delivery and testing of a 3 kW system at National Energy Technology Laboratory (NETL). Subsequently, the project was re-aligned into a three phase effort with the main goal to develop SOFC technology for application in coal-fueled power plants with >90% carbon capture. Phase I of the Coal-based efforts focused on cell and stack size scale-up with concurrent enhancement of performance, life, cost, and manufacturing characteristics. Also in Phase I, design and analysis of the baseline (greater than 100 MW) power plant system—including concept identification, system definition, and cost analysis—was conducted. Phase II efforts focused on development of a ≥25 kW SOFC stack tower incorporating multiple stack building

  16. Integrated Solid Oxide Fuel Cell Power System Characteristics Prediction

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2009-07-01

    Full Text Available The main objective of this paper is to deduce the specific characteristics of the CHP 100kWe Solid Oxide Fuel Cell (SOFC Power System from the steady state experimental data. From the experimental data, the authors have been developed and validated the steady state mathematical model. From the control room the steady state experimental data of the SOFC power conditioning are available and using the developed steady state mathematical model, the authors have been obtained the characteristic curves of the system performed by Siemens-Westinghouse Power Corporation. As a methodology the backward and forward power flow analysis has been employed. The backward power flow makes possible to obtain the SOFC power system operating point at different load levels, resulting as the load characteristic. By knowing the fuel cell output characteristic, the forward power flow analysis is used to predict the power system efficiency in different operating points, to choose the adequate control decision in order to obtain the high efficiency operation of the SOFC power system at different load levels. The CHP 100kWe power system is located at Gas Turbine Technologies Company (a Siemens Subsidiary, TurboCare brand in Turin, Italy. The work was carried out through the Energia da Ossidi Solidi (EOS Project. The SOFC stack delivers constant power permanently in order to supply the electric and thermal power both to the TurboCare Company and to the national grid.

  17. GCtool for fuel cell systems design and analysis : user documentation.

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, R.K.; Geyer, H.K.

    1999-01-15

    GCtool is a comprehensive system design and analysis tool for fuel cell and other power systems. A user can analyze any configuration of component modules and flows under steady-state or dynamic conditions. Component models can be arbitrarily complex in modeling sophistication and new models can be added easily by the user. GCtool also treats arbitrary system constraints over part or all of the system, including the specification of nonlinear objective functions to be minimized subject to nonlinear, equality or inequality constraints. This document describes the essential features of the interpreted language and the window-based GCtool environment. The system components incorporated into GCtool include a gas flow mixer, splitier, heater, compressor, gas turbine, heat exchanger, pump, pipe, diffuser, nozzle, steam drum, feed water heater, combustor, chemical reactor, condenser, fuel cells (proton exchange membrane, solid oxide, phosphoric acid, and molten carbonate), shaft, generator, motor, and methanol steam reformer. Several examples of system analysis at various levels of complexity are presented. Also given are instructions for generating two- and three-dimensional plots of data and the details of interfacing new models to GCtool.

  18. Molybdenum-tin as a solar cell metallization system

    Science.gov (United States)

    Boyd, D. W.; Radics, C.

    The operations of solar cell manufacture are briefly examined. The formation of reliable, ohmic, low-loss, and low-cost metal contacts on solar cells is a critical process step in cell manufacturing. In a commonly used process, low-cost metallization is achieved by screen printing a metal powder-glass frit ink on the surface of the Si surface and the conductive metal powder. A technique utilizing a molybdenum-tin alloy for the metal contacts appears to lower the cost of materials and to reduce process complexity. The ink used in this system is formulated from MoO3 with Sn powder and a trace amount of titanium resonate. Resistive losses of the resulting contacts are low because the ink contains no frit. The MoO3 is finally melted and reduced in forming gas (N2+H2) to Mo metal. The resulting Mo is highly reactive which facilitates the Mo-Si bonding.

  19. Complex Systems Analysis of Arrested Neural Cell Differentiation during Development and Analogous Cell Cycling Models in Carcinogenesis

    OpenAIRE

    Baianu, Professor I.C.; Prisecaru, M.S. V

    2004-01-01

    A new approach to the modular, complex systems analysis of nonlinear dynamics of arrested neural cell Differentiation--induced cell proliferation during organismic development and the analogous cell cycling network transformations involved in carcinogenesis is proposed. Neural tissue arrested differentiation that induces cell proliferation during perturbed development and Carcinogenesis are complex processes that involve dynamically inter-connected biomolecules in the intercellular, membrane...

  20. System model development for a methanol reformed 5 kW high temperature PEM fuel cell system

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2015-01-01

    This work investigates the system performance when reforming methanol in an oil heated reformer system for a 5 kW fuel cell system. A dynamic model of the system is created and evaluated. The system is divided into 4 separate components. These components are the fuel cell, reformer, burner and...

  1. Modulation of Programmed Cell Death in a Model System of Xylogenic Zinnia (Zinnia Elegans) Cell Culture

    NARCIS (Netherlands)

    Yakimova, E.T.; Woltering, E.J.

    2009-01-01

    Programmed cell death is an integral part of the latest stage of differentiation of the tracheary elements of plant xylem vascular system. In this study, by applying a pharmacological approach with specific peptide inhibitors, we have elucidated the involvement of plant caspase-like proteases in cel

  2. Life cycle assessment of roof integrated solar cell systems

    International Nuclear Information System (INIS)

    The research protocol, applied in this report, is designed for use within the energy R and D-context: it provides a framework for finding bottlenecks and opportunities for (new) energy technologies in the context of (energy) resource scarcity and environmental issues. Finding and analyzing these bottlenecks and opportunities is a major objective of this study. A derived objective of this study is to gain experience in using the LCA-framework and the research protocol described earlier, and to evaluate the usefulness of these instruments in helping to find and analyze bottlenecks and opportunities in energy technologies. Photovoltaic solar cell systems (PV systems) are comprised of solar cell modules and a Balance-of-System (BOS): a support structure and power conditioning equipment. In this LCA amorphous silicon cells (a-Si) are considered. For the Netherlands roof-integrated, grid-connected systems are assumed to be the major application of PV in the future. Two cases will be studied. In case 1 a system of 30 m2 of modules which are connected to the grid via a single inverter are studied. The modules are comprised of a-Si cells and have a conversion efficiency of 10%. Integration into the roof is done with aluminium profiles. In case 2 a system of 30 m2 a-Si cell modules integrated in the roof with plastic 'tiles' is studied. The modules have an efficiency of 15% and connection to the grid is more or less centralized: 25 systems share an inverter which is connected to the grid. The goal and scope of the LCA and the functional unit are described in chapter 2. In chapter 3 the process tree and descriptions of the distinguished processes are given and the inventory table is drawn up. In chapter 4 the impact assessment is dealt with, followed by a discussion of improvement options in chapter 5. Conclusions and recommendations are given in the chapters 6 and 7 only regarding the environmental aspects. 9 figs., 13 tabs., 4 appendices, 13 refs

  3. Back-Up/ Peak Shaving Fuel Cell System

    Energy Technology Data Exchange (ETDEWEB)

    Staudt, Rhonda L.

    2008-05-28

    This Final Report covers the work executed by Plug Power from 8/11/03 – 10/31/07 statement of work for Topic 2: advancing the state of the art of fuel cell technology with the development of a new generation of commercially viable, stationary, Back-up/Peak-Shaving fuel cell systems, the GenCore II. The Program cost was $7.2 M with the Department of Energy share being $3.6M and Plug Power’s share being $3.6 M. The Program started in August of 2003 and was scheduled to end in January of 2006. The actual program end date was October of 2007. A no cost extension was grated. The Department of Energy barriers addressed as part of this program are: Technical Barriers for Distributed Generation Systems: o Durability o Power Electronics o Start up time Technical Barriers for Fuel Cell Components: o Stack Material and Manufacturing Cost o Durability o Thermal and water management Background The next generation GenCore backup fuel cell system to be designed, developed and tested by Plug Power under the program is the first, mass-manufacturable design implementation of Plug Power’s GenCore architected platform targeted for battery and small generator replacement applications in the telecommunications, broadband and UPS markets. The next generation GenCore will be a standalone, H2 in-DC-out system. In designing the next generation GenCore specifically for the telecommunications market, Plug Power is teaming with BellSouth Telecommunications, Inc., a leading industry end user. The final next generation GenCore system is expected to represent a market-entry, mass-manufacturable and economically viable design. The technology will incorporate: • A cost-reduced, polymer electrolyte membrane (PEM) fuel cell stack tailored to hydrogen fuel use • An advanced electrical energy storage system • A modular, scalable power conditioning system tailored to market requirements • A scaled-down, cost-reduced balance of plant (BOP) • Network Equipment Building Standards (NEBS), UL

  4. Single Cell Analysis of a Bacterial Sender-Receiver System.

    Science.gov (United States)

    Ramalho, Tiago; Meyer, Andrea; Mückl, Andrea; Kapsner, Korbinian; Gerland, Ulrich; Simmel, Friedrich C

    2016-01-01

    Monitoring gene expression dynamics on the single cell level provides important information on cellular heterogeneity and stochasticity, and potentially allows for more accurate quantitation of gene expression processes. We here study bacterial senders and receivers genetically engineered with components of the quorum sensing system derived from Aliivibrio fischeri on the single cell level using microfluidics-based bacterial chemostats and fluorescence video microscopy. We track large numbers of bacteria over extended periods of time, which allows us to determine bacterial lineages and filter out subpopulations within a heterogeneous population. We quantitatively determine the dynamic gene expression response of receiver bacteria to varying amounts of the quorum sensing inducer N-3-oxo-C6-homoserine lactone (AHL). From this we construct AHL response curves and characterize gene expression dynamics of whole bacterial populations by investigating the statistical distribution of gene expression activity over time. The bacteria are found to display heterogeneous induction behavior within the population. We therefore also characterize gene expression in a homogeneous bacterial subpopulation by focusing on single cell trajectories derived only from bacteria with similar induction behavior. The response at the single cell level is found to be more cooperative than that obtained for the heterogeneous total population. For the analysis of systems containing both AHL senders and receiver cells, we utilize the receiver cells as 'bacterial sensors' for AHL. Based on a simple gene expression model and the response curves obtained in receiver-only experiments, the effective AHL concentration established by the senders and their 'sending power' is determined. PMID:26808777

  5. MCF-10A-NeoST: A New Cell System for Studying Cell-ECM and Cell-Cell Interactions in Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zantek, Nicole Dodge; Walker-Daniels, Jennifer; Stewart, Jane; Hansen, Rhonda K.; Robinson, Daniel; Miao, Hui; Wang, Bingcheng; Kung, Hsing-Jien; Bissell, Mina J.; Kinch, Michael S.

    2001-08-22

    There is a continuing need for genetically matched cell systems to model cellular behaviors that are frequently observed in aggressive breast cancers. We report here the isolation and initial characterization of a spontaneously arising variant of MCF-10A cells, NeoST, which provides a new model to study cell adhesion and signal transduction in breast cancer. NeoST cells recapitulate important biological and biochemical features of metastatic breast cancer, including anchorage-independent growth, invasiveness in threedimensional reconstituted membranes, loss of E-cadherin expression, and increased tyrosine kinase activity. A comprehensive analysis of tyrosine kinase expression revealed overexpression or functional activation of the Axl, FAK, and EphA2 tyrosine kinases in transformed MCF-10A cells. MCF-10A and these new derivatives provide a genetically matched model to study defects in cell adhesion and signaling that are relevant to cellular behaviors that often typify aggressive breast cancer cells.

  6. Model-based fault diagnosis in PEM fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Escobet, T.; de Lira, S.; Puig, V.; Quevedo, J. [Automatic Control Department (ESAII), Universitat Politecnica de Catalunya (UPC), Rambla Sant Nebridi 10, 08222 Terrassa (Spain); Feroldi, D.; Riera, J.; Serra, M. [Institut de Robotica i Informatica Industrial (IRI), Consejo Superior de Investigaciones Cientificas (CSIC), Universitat Politecnica de Catalunya (UPC) Parc Tecnologic de Barcelona, Edifici U, Carrer Llorens i Artigas, 4-6, Planta 2, 08028 Barcelona (Spain)

    2009-07-01

    In this work, a model-based fault diagnosis methodology for PEM fuel cell systems is presented. The methodology is based on computing residuals, indicators that are obtained comparing measured inputs and outputs with analytical relationships, which are obtained by system modelling. The innovation of this methodology is based on the characterization of the relative residual fault sensitivity. To illustrate the results, a non-linear fuel cell simulator proposed in the literature is used, with modifications, to include a set of fault scenarios proposed in this work. Finally, it is presented the diagnosis results corresponding to these fault scenarios. It is remarkable that with this methodology it is possible to diagnose and isolate all the faults in the proposed set in contrast with other well known methodologies which use the binary signature matrix of analytical residuals and faults. (author)

  7. Modeling and Optimization of PEMFC Systems and its Application to Direct Hydrogen Fuel Cell Vehicles

    OpenAIRE

    Zhao, Hengbing; Burke, Andy

    2008-01-01

    Proton Exchange Membrane fuel cell (PEMFC) technology for use in fuel cell vehicles and other applications has been extensively developed in recent decades. Besides the fuel cell stack, air and fuel control, and thermal and water management are major challenges in the fuel cell vehicle development. The air supply system can have a major impact on overall system efficiency. In this report, a fuel cell system model for optimizing system operating conditions was developed which includes the tran...

  8. Solid oxide fuel cell systems development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    The main objective in this project has been to develop a generic and dynamic tool for SOFC systems simulation and development. Developing integrated fuel cell systems is very expensive and therefore having the right tools to reduce the development cost and time to market for products becomes an important feature. The tools developed in this project cover a wide range of needs in Dantherm Power, R and D, and can be divided into 3 categories: 1. Component selection modeling; to define component specification requirements and selection of suppliers. 2. Application simulation model built from scratch, which can simulate the interface between customer demand and system output and show operation behavior for different control settings. 3. System operation strategy optimization with respect to operation cost and customer benefits. a. Allows to see how system size, in terms of electricity and heat output, and operation strategy influences a specific business case. b. Gives a clear overview of how a different property, in the system, affects the economics (e.g. lifetime, electrical and thermal efficiency, fuel cost sensitivity, country of deployment etc.). The main idea behind the structure of the tool being separated into 3 layers is to be able to service different requirements, from changing stakeholders. One of the major findings in this project has been related to thermal integration between the existing installation in a private household and the fuel cell system. For a normal family requiring 4500 kWh of electricity a year, along with the possibility of only running the system during the heating season (winter), the heat storage demand is only 210kWh of heat with an approximate value of Dkr 160,- in extra gas consumption. In this case, it would be much more cost effective to dump the heat, in the house, and save the expense of adding heat storage to the system. This operation strategy is only valid in Denmark for the time being, since the feed-In-Tariff allows for a

  9. The Cellulose System in the Cell Wall of Micrasterias

    Science.gov (United States)

    Kim; Herth; Vuong; Chanzy

    1996-11-01

    The cellulose system of the cell wall of Micrasterias denticulata and Micrasterias rotata was analyzed by diffraction contrast transmission electron microscopy, electron diffraction, and X-ray analysis. The studies, achieved on disencrusted cell ghosts, confirmed that the cellulose microfibrils occurred in crisscrossed bands consisting of a number of parallel ribbon-like microfibrils. The individual microfibrils had thicknesses of 5 nm for a width of around 20 nm, but in some instances, two or three microfibrils merged into one another to yield larger monocrystalline domains reaching up to 60 nm in lateral size. The orientation of the cellulose of Micrasterias is very unusual, as it was found that in the cell wall, the equatorial crystallographic planes of cellulose having a d-spacing of 0.60 nm [(11;0) in the Ibeta cellulose unit cell defined by Sugiyama et al., 1991, Macromolecules 24, 4168-4175] were oriented perpendicular to the cell wall surface. Up to now, such orientation has been found only in Spirogyra, another member of the Zygnemataceae group. The unusual structure of the secondary wall cellulose of Micrasterias may be tentatively correlated with the unique organization of the terminal complexes, which in this alga occur as hexagonal arrays of rosettes. PMID:8986649

  10. Multiplexed labeling system for high-throughput cell sorting.

    Science.gov (United States)

    Shin, Seung Won; Park, Kyung Soo; Song, In Hyun; Shin, Woo Jung; Kim, Byung Woo; Kim, Dong-Ik; Um, Soong Ho

    2016-09-01

    Flow cytometry and fluorescence activated cell sorting techniques were designed to realize configurable classification and separation of target cells. A number of cell phenotypes with different functionalities have recently been revealed. Before simultaneous selective capture of cells, it is desirable to label different samples with the corresponding dyes in a multiplexing manner to allow for a single analysis. However, few methods to obtain multiple fluorescent colors for various cell types have been developed. Even when restricted laser sources are employed, a small number of color codes can be expressed simultaneously. In this study, we demonstrate the ability to manifest DNA nanostructure-based multifluorescent colors formed by a complex of dyes. Highly precise self-assembly of fluorescent dye-conjugated oligonucleotides gives anisotropic DNA nanostructures, Y- and tree-shaped DNA (Y-DNA and T-DNA, respectively), which may be used as platforms for fluorescent codes. As a proof of concept, we have demonstrated seven different fluorescent codes with only two different fluorescent dyes using T-DNA. This method provides maximum efficiency for current flow cytometry. We are confident that this system will provide highly efficient multiplexed fluorescent detection for bioanalysis compared with one-to-one fluorescent correspondence for specific marker detection. PMID:27181032

  11. GaAs solar cells for concentrator systems in space

    Science.gov (United States)

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

    1983-01-01

    Cells for operation in space up to more than 100 suns were made, and an AMO efficiency of 21% at 100 suns with these cells was obtained. The increased efficiency resulted not only from the higher open circuit voltage associated with the higher light intensity (higher short circuit current); it also benefitted from the increase in fill factor caused by the lower relative contribution of the generation recombination current to the forward bias current when the cell's operating current density is increased. The experimental cells exhibited an AMO efficiency close to 16% at 200 C. The prospect of exploiting this capability for the continuous annealing of radiation damage or for high temperature missions (e.g., near Sun missions) remains therefore open. Space systems with concentration ratios on the order of 100 suns are presently under development. The tradeoff between increased concentration ratio and increased loss due to the cell's series resistance remains attractive even for space applications at a solar concentrator ratio of 100 suns. In the design of contact configuration with low enough series resistance for such solar concentration ratios, the shallow junction depth needed for good radiation hardness and the thin AlGaAs layer thickness needed to avoid excessive optical absorption losses have to be retained.

  12. T Cell Transcriptomes Describe Patient Subtypes in Systemic Lupus Erythematosus.

    Directory of Open Access Journals (Sweden)

    Sean J Bradley

    Full Text Available T cells regulate the adaptive immune response and have altered function in autoimmunity. Systemic Lupus Erythematosus (SLE has great diversity of presentation and treatment response. Peripheral blood component gene expression affords an efficient platform to investigate SLE immune dysfunction and help guide diagnostic biomarker development for patient stratification.Gene expression in peripheral blood T cell samples for 14 SLE patients and 4 controls was analyzed by high depth sequencing. Unbiased clustering of genes and samples revealed novel patterns related to disease etiology. Functional annotation of these genes highlights pathways and protein domains involved in SLE manifestation.We found transcripts for hundreds of genes consistently altered in SLE T cell samples, for which DAVID analysis highlights induction of pathways related to mitochondria, nucleotide metabolism and DNA replication. Fewer genes had reduced mRNA expression, and these were linked to signaling, splicing and transcriptional activity. Gene signatures associated with the presence of dsDNA antibodies, low complement levels and nephritis were detected. T cell gene expression also indicates the presence of several patient subtypes, such as having only a minimal expression phenotype, male type, or severe with or without induction of genes related to membrane protein production.Unbiased transcriptome analysis of a peripheral blood component provides insight on autoimmune pathophysiology and patient variability. We present an open source workflow and richly annotated dataset to support investigation of T cell biology, develop biomarkers for patient stratification and perhaps help indicate a source of SLE immune dysfunction.

  13. Gravisensing in single-celled systems: characean rhizoids and protonemata

    Science.gov (United States)

    Braun, M.

    Gravitropically tip-growing cell types are attractive unicellular model systems for investigating the mechanisms and the regulation of gravitropism. Especially useful for studying the mechanisms of positive and negative gravitropic tip-growth are characean rhizoids and protonemata. They originate from the same cell type, show the same overall cell shape, cytoplasmic zonation, arrangement of actin and microtubule cytoskeleton, use statoliths for gravisensing, but show opposite gravitropism. In both cell types, actin microfilaments are complexly organized in the apical dome, where a dense spherical actin array is colocalized with spectrin-like epitopes and a unique endoplasmic reticulum aggregate, the structural center of the Spitzenkörper. The opposite gravitropic responses seem to be based on differences in the actin-organized anchorage of the Spitzenkörper and the actin-mediated transport of statoliths. In negatively gravitropic (upward bending) protonemata, the statoliths-induced drastic upward shift of the cell tip is preceded by a relocalization of dihydropyridine-binding calcium channels and of the apical calcium gradient to the upper flank (bending by bulging). Such relocalizations have not been observed in positively gravitropically responding (downward growing) rhizoids in which statoliths sedimentation is followed by differential flank growth (bending by bowing). This paper reviews the current knowledge and hypotheses on the mechanisms of the opposite gravitropic responses in characean rhizoids and protonemata.

  14. Materials selection for solid oxide fuel cells (SOFCs) systems

    International Nuclear Information System (INIS)

    Because fuel cells, as electrochemical devices, convert fuels such as hydrogen into electricity without combustion they create virtually no pollution and hold the key to future prosperity and a healthy global environment. In recent years, the development and commercialisation of fuel cells systems for different applications is increasing tremendously. A discussion in made, in this paper, upon the benefits obtained from the few potential applications and the future of such devices with a particular, attention being given to design (and operation of Solid Oxide Fuel Cells (SOFCs), nothing the restrictions based on materials requirements and fuel specifications. The materials selection for this kind of fuel cells is very difficult due to the temperature range they operate in. The advantage and limitations, development state, and technical issues for novel materials used in SOFC electrodes, electrolyte and interconnect, that are the subject of a majority of contemporary research, and their properties are reviewed and discussed. A complete scenario is proposed as a competitive energy policy and a step forward to the target of sustainable development. It is emphasised that fuel cells will be a significant contributor within a portfolio of energy sources in the coming 10 to 20 years.(Author)

  15. Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems

    Science.gov (United States)

    Mittelsteadt, Cortney K.; Braff, William

    2009-01-01

    In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a polymer that has very high water transport properties. Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center.

  16. Integration of Antennas and Solar Cells for Autonomous Communication Systems

    OpenAIRE

    Roo Ons, Maria Jose, (Thesis)

    2010-01-01

    Solar energy is becoming an attractive alternative for powering autonomous communication systems. These devices often involve the use of separate photovoltaics and antennas, which demand a compromise in the utilization of the limited space available. This thesis deals with the design, analysis, fabrication and validation of different techniques for the integration of antennas and solar cells in a single multifunctional device. Four different photovoltaic technologies are considered within thi...

  17. Systems-biology dissection of eukaryotic cell growth

    Directory of Open Access Journals (Sweden)

    Andrews Justen

    2010-05-01

    Full Text Available Abstract A recent article in BMC Biology illustrates the use of a systems-biology approach to integrate data across the transcriptome, proteome and metabolome of budding yeast in order to dissect the relationship between nutrient conditions and cell growth. See research article http://jbiol.com/content/6/2/4 and http://www.biomedcentral.com/1741-7007/8/68

  18. A cell-based model system links chromothripsis with hyperploidy

    DEFF Research Database (Denmark)

    Mardin, Balca R; Drainas, Alexandros P; Waszak, Sebastian M;

    2015-01-01

    A remarkable observation emerging from recent cancer genome analyses is the identification of chromothripsis as a one-off genomic catastrophe, resulting in massive somatic DNA structural rearrangements (SRs). Largely due to lack of suitable model systems, the mechanistic basis of chromothripsis h...... hyperploid cells. Analysis of primary medulloblastoma cancer genomes verified the link between hyperploidy and chromothripsis in vivo. CAST provides the foundation for mechanistic dissection of complex DNA rearrangement processes....

  19. Accelerating Acceptance of Fuel Cell Backup Power Systems - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Petrecky, James; Ashley, Christopher

    2014-07-21

    Since 2001, Plug Power has installed more than 800 stationary fuel cell systems worldwide. Plug Power’s prime power systems have produced approximately 6.5 million kilowatt hours of electricity and have accumulated more than 2.5 million operating hours. Intermittent, or backup, power products have been deployed with telecommunications carriers and government and utility customers in North and South America, Europe, the United Kingdom, Japan and South Africa. Some of the largest material handling operations in North America are currently using the company’s motive power units in fuel cell-powered forklifts for their warehouses, distribution centers and manufacturing facilities. The low-temperature GenSys fuel cell system provides remote, off-grid and primary power where grid power is unreliable or nonexistent. Built reliable and designed rugged, low- temperature GenSys delivers continuous or backup power through even the most extreme conditions. Coupled with high-efficiency ratings, low-temperature GenSys reduces operating costs making it an economical solution for prime power requirements. Currently, field trials at telecommunication and industrial sites across the globe are proving the advantages of fuel cells—lower maintenance, fuel costs and emissions, as well as longer life—compared with traditional internal combustion engines.

  20. Fuel cell systems for first lunar outpost: Reactant storage options

    Science.gov (United States)

    Nelson, P. A.

    A Lunar Surface Power Working Group was formed to review candidate systems for providing power to the First Lunar Outpost habitat. The working group met for five days in the fall of 1992 and concluded that the most attractive candidate included a photovoltaic unit, a fuel cell, a regenerator to recycle the reactants, and storage of oxygen and hydrogen gases. Most of the volume (97%) and weight (64%) are taken up by the reactants and their storage tanks. The large volume is difficult to accommodate, and therefore, the working group explored ways of reducing the volume. An alternative approach to providing separate high pressure storage tanks is to use two of the descent stage propellant storage tanks, which would have to be wrapped with graphite fibers to increase their pressure capability. This saves 90% of the volume required for storage of fuel cell reactants. Another approach is to use the descent storage propellant tanks for storage of the fuel cell reactants as cryogenic liquids, but this requires a gas liquefaction system, increases the solar array by 40%, and increases the heat rejection rate by 170% compared with storage of reactants as high pressure gases. For a high power system (greater than 20 kW) the larger energy storage requirement would probably favor the cryogenic storage option.

  1. Quantitative Analysis of AGV System in FMS Cell Layout

    Directory of Open Access Journals (Sweden)

    B. Ramana

    1997-01-01

    Full Text Available Material handling is a specialised activity for a modern manufacturing concern. Automated guided vehicles (AGVs are invariably used for material handling in flexible manufacturing Systems (FMSs due to their flexibility. The quantitative analysis of an AGV system is useful for determining the material flow rates, operation times, length of delivery, length of empty move of AGV and the number of AGVs required for a typical FMS cell layout. The efficiency of the material handling system, such as AGV can be improved by reducing the length of empty move. The length of empty move of AGV depends upon despatching and scheduling methods. If these methods of AGVs are not properly planned, the length of empty move of AGV is greater than the length of delivery .This results in increase in material handling time which in turn increases the number of AGVs required in FMS cell. This paper presents a method for optimising the length of empty travel of AGV in a typical FMS cell layout.

  2. Evaluation of CBA first string full cell vacuum system

    International Nuclear Information System (INIS)

    The CBA (Colliding Beam Accelerator, formerly known as ISABELLE) Full Cell Magnet System consisting of six superconducting dipole magnets and two superconducting quadrupole magnets requires two separate vacuum systems. One, known as beam vacuum operates below 3 x 10-11 Torr and the other, known as insulating vacuum, operates at less than 10-7 Torr to isolate cryo circuits from atmosphere and from the uhv beam tubes. The uhv bore tube is isolated from the 4.00K magnet by thirty-six (36) layers of superinsulation and insulating vacuum. Heat load measurements on the bore tube have been completed and found to agree with data obtained in smaller controlled experiments. Measurements of helium, accumulated on cryogenic pumped charcoal panels over many weeks, have verified sensitive helium mass spectrometer leak detection methods for vacuum integrity, providing sound design of the welded complex. The Full Cell was assembled and operated under conditions that would exist in the completed machine. Pressures below 2 x 10-11 Torr beam vacuum requirement and below 2 x 10-7 Torr insulating vacuum, were routinely achieved during all phases of the Full Cell operation and support systems testing

  3. Fuel-cell-propelled submarine-tanker-system study

    Energy Technology Data Exchange (ETDEWEB)

    Court, K E; Kumm, W H; O' Callaghan, J E

    1982-06-01

    This report provides a systems analysis of a commercial Arctic Ocean submarine tanker system to carry fossil energy to markets. The submarine is to be propelled by a modular Phosphoric Acid Fuel Cell system. The power level is 20 Megawatts. The DOE developed electric utility type fuel cell will be fueled with methanol. Oxidant will be provided from a liquid oxygen tank carried onboard. The twin screw submarine tanker design is sized at 165,000 deadweight tons and the study includes costs and an economic analysis of the transport system of 6 ships. The route will be under the polar icecap from a loading terminal located off Prudhoe Bay, Alaska to a transshipment facility postulated to be in a Norwegian fjord. The system throughput of the gas-fed methanol cargo will be 450,000 barrels per day. The total delivered cost of the methanol including well head purchase price of natural gas, methanol production, and shipping would be $25/bbl from Alaska to the US East Coast. Of this, the shipping cost is $6.80/bbl. All costs in 1981 dollars.

  4. Fuel-cell-propelled submarine-tanker-system study

    International Nuclear Information System (INIS)

    This report provides a systems analysis of a commercial Arctic Ocean submarine tanker system to carry fossil energy to markets. The submarine is to be propelled by a modular Phosphoric Acid Fuel Cell system. The power level is 20 Megawatts. The DOE developed electric utility type fuel cell will be fueled with methanol. Oxidant will be provided from a liquid oxygen tank carried onboard. The twin screw submarine tanker design is sized at 165,000 deadweight tons and the study includes costs and an economic analysis of the transport system of 6 ships. The route will be under the polar icecap from a loading terminal located off Prudhoe Bay, Alaska to a transshipment facility postulated to be in a Norwegian fjord. The system throughput of the gas-fed methanol cargo will be 450,000 barrels per day. The total delivered cost of the methanol including well head purchase price of natural gas, methanol production, and shipping would be $25/bbl from Alaska to the US East Coast. Of this, the shipping cost is $6.80/bbl. All costs in 1981 dollars

  5. Design of improved fuel cell controller for distributed generation systems

    Energy Technology Data Exchange (ETDEWEB)

    Olsen Berenguer, F.A. [Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste, 1109, J5400ARL San Juan (Argentina); Molina, M.G. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste, 1109, J5400ARL San Juan (Argentina)

    2010-06-15

    The world has been undergoing a deregulation process which allowed competition in the electricity generation sector. This situation is bringing the opportunity for electricity users to generate power by using small-scale generation systems with emerging technologies, allowing the development of distributed generation (DG). A fuel cell power plant (FCPP) is a distributed generation technology with a rapid development because it has promising characteristics, such as low pollutant emissions, silent operation, high efficiency and long lifetime because of its small number of moving parts. The power conditioning system (PCS) is the interface that allows the effective connection to the electric power system. With the appropriate topology of the PCS and its control system design, the FCPP unit is capable of simultaneously performing both instantaneous active and reactive power flow control. This paper describes the design and implementation of a novel high performance PCS of an FCPP and its controller, for applications in distributed generation systems. A full detailed model of the FCPP is derived and a new three-level control scheme is designed. The dynamic performance of the proposed system is validated by digital simulation in SimPowerSystems (SPS) of MATLAB/Simulink. (author)

  6. Magnetic microfluidic system for isolation of single cells

    Science.gov (United States)

    Mitterboeck, Richard; Kokkinis, Georgios; Berris, Theocharis; Keplinger, Franz; Giouroudi, Ioanna

    2015-06-01

    This paper presents the design and realization of a compact, portable and cost effective microfluidic system for isolation and detection of rare circulating tumor cells (CTCs) in suspension. The innovative aspect of the proposed isolation method is that it utilizes superparamagnetic particles (SMPs) to label CTCs and then isolate those using microtraps with integrated current carrying microconductors. The magnetically labeled and trapped CTCs can then be detected by integrated magnetic microsensors e.g. giant magnetoresistive (GMR) or giant magnetoimpedance (GMI) sensors. The channel and trap dimensions are optimized to protect the cells from shear stress and achieve high trapping efficiency. These intact single CTCs can then be used for additional analysis, testing and patient specific drug screening. Being able to analyze the CTCs metastasis-driving capabilities on the single cell level is considered of great importance for developing patient specific therapies. Experiments showed that it is possible to capture single labeled cells in multiple microtraps and hold them there without permanent electric current and magnetic field.

  7. Rapid detection of microbial cell abundance in aquatic systems.

    Science.gov (United States)

    Rocha, Andrea M; Yuan, Quan; Close, Dan M; O'Dell, Kaela B; Fortney, Julian L; Wu, Jayne; Hazen, Terry C

    2016-11-15

    The detection and quantification of naturally occurring microbial cellular densities is an essential component of environmental systems monitoring. While there are a number of commonly utilized approaches for monitoring microbial abundance, capacitance-based biosensors represent a promising approach because of their low-cost and label-free detection of microbial cells, but are not as well characterized as more traditional methods. Here, we investigate the applicability of enhanced alternating current electrokinetics (ACEK) capacitive sensing as a new application for rapidly detecting and quantifying microbial cellular densities in cultured and environmentally sourced aquatic samples. ACEK capacitive sensor performance was evaluated using two distinct and dynamic systems - the Great Australian Bight and groundwater from the Oak Ridge Reservation in Oak Ridge, TN. Results demonstrate that ACEK capacitance-based sensing can accurately determine microbial cell counts throughout cellular concentrations typically encountered in naturally occurring microbial communities (10(3)-10(6) cells/mL). A linear relationship was observed between cellular density and capacitance change correlations, allowing a simple linear curve fitting equation to be used for determining microbial abundances in unknown samples. This work provides a foundation for understanding the limits of capacitance-based sensing in natural environmental samples and supports future efforts focusing on evaluating the robustness ACEK capacitance-based within aquatic environments. PMID:27315516

  8. Dynamic neural network controller model of PEM fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Hatti, Mustapha [Nuclear Technologies Division, Nuclear Research Center of Birine, Ain Oussera, B.P 180, 17200 Djelfa (Algeria); Tioursi, Mustapha [Electrical Engineering Department, University of Sciences and Technology of Oran, B.P 1505, El M' Naouar, 31000 Oran (Algeria)

    2009-06-15

    This paper presents the artificial intelligence techniques to control a proton exchange membrane fuel cell system process, using particularly a methodology of dynamic neural network. In this work a dynamic neural network control model is obtained by introducing a delay line in the input of the neural network. A static production system including a PEMFC is subjected to variations of active and reactive power. Therefore the goal is to make the system follow these imposed variations. The simulation requires the modelling of the principal element (PEMFC) in dynamic mode. The simulation results demonstrate that the model-based dynamic neural network control scheme is appropriate for controlling, the stability of the identification and the tracking error were analyzed, and some reasons for the usefulness of this methodology are given. (author)

  9. Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL) Reveals the Sequential Differentiation of Sieve Element-Like Cells.

    Science.gov (United States)

    Kondo, Yuki; Nurani, Alif Meem; Saito, Chieko; Ichihashi, Yasunori; Saito, Masato; Yamazaki, Kyoko; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Fukuda, Hiroo

    2016-06-01

    Cell differentiation is a complex process involving multiple steps, from initial cell fate specification to final differentiation. Procambial/cambial cells, which act as vascular stem cells, differentiate into both xylem and phloem cells during vascular development. Recent studies have identified regulatory cascades for xylem differentiation. However, the molecular mechanism underlying phloem differentiation is largely unexplored due to technical challenges. Here, we established an ectopic induction system for phloem differentiation named Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL). Our results verified similarities between VISUAL-induced Arabidopsis thaliana phloem cells and in vivo sieve elements. We performed network analysis using transcriptome data with VISUAL to dissect the processes underlying phloem differentiation, eventually identifying a factor involved in the regulation of the master transcription factor gene APL Thus, our culture system opens up new avenues not only for genetic studies of phloem differentiation, but also for future investigations of multidirectional differentiation from vascular stem cells. PMID:27194709

  10. Adult neural stem cells in the mammalian central nervous system

    Institute of Scientific and Technical Information of China (English)

    Dengke K Ma; Michael A Bonaguidi; Guo-li Ming; Hongjun Song

    2009-01-01

    Neural stem cells (NSCs) are present not only during the embryonic development but also in the adult brain of all mammalian species, including humans. Stem cell niche architecture in vivo enables adult NSCs to continuously generate functional neurons in specific brain regions throughout life. The adult neurogenesis process is subject to dynamic regulation by various physiological, pathological and pharmacological stimuli. Multipotent adult NSCs also appear to be intrinsically plastic, amenable to genetic programing during normal differentiation, and to epigenetic reprograming during de-differentiation into pluripotency. Increasing evidence suggests that adult NSCs significantly contribute to specialized neural functions under physiological and pathological conditions. Fully understanding the biology of adult NSCs will provide crucial insights into both the etiology and potential therapeutic interventions of major brain disorders. Here, we review recent progress on adult NSCs of the mammalian central nervous system, in-cluding topics on their identity, niche, function, plasticity, and emerging roles in cancer and regenerative medicine.

  11. Gill cell culture systems as models for aquatic environmental monitoring.

    Science.gov (United States)

    Bury, Nic R; Schnell, Sabine; Hogstrand, Christer

    2014-03-01

    A vast number of chemicals require environmental safety assessments for market authorisation. To ensure acceptable water quality, effluents and natural waters are monitored for their potential harmful effects. Tests for market authorisation and environmental monitoring usually involve the use of large numbers of organisms and, for ethical, cost and logistic reasons, there is a drive to develop alternative methods that can predict toxicity to fish without the need to expose any animals. There is therefore a great interest in the potential to use cultured fish cells in chemical toxicity testing. This review summarises the advances made in the area and focuses in particular on a system of cultured fish gill cells grown into an epithelium that permits direct treatment with water samples. PMID:24574380

  12. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system

    OpenAIRE

    Enrique Montalvillo; José Antonio Garrote; David Bernardo; Eduardo Arranz

    2014-01-01

    The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on inn...

  13. Human adipose-derived mesenchymal stem cells: a better cell source for nervous system regeneration

    Institute of Scientific and Technical Information of China (English)

    Han Chao; Zhang Liang; Song Lin; Liu Yang; Zou Wei; Piao Hua; Liu Jing

    2014-01-01

    Background In order to suggest an ideal source of adult stem cells for the treatment of nervous system diseases,MSCs from human adipose tissue and bone marrow were isolated and studied to explore the differences with regard to cell morphology,surface markers,neuronal differentiation capacity,especially the synapse structure formation and the secretion of neurotrophic factors.Methods The neuronal differentiation capacity of human mesenchymal stem cells from adipose tissue (hADSCs) and bone marrow (hBMSCs) was determined based on nissl body and synapse structure formation,and neural factor secretion function.hADSCs and hBMSCs were isolated and differentiated into neuron-like cells with rat brain-conditioned medium,a potentially rich source of neuronal differentiation promoting signals.Specific neuronal proteins and neural factors were detected by immunohistochemistry and enzyme-linked immunosorbent assay analysis,respectively.Results Flow cytometric analysis showed that both cell types had similar phenotypes.Cell growth curves showed that hADSCs proliferated more quickly than hBMSCs.Both kinds of cells were capable of osteogenic and adipogenic differentiation.The morphology of hADSCs and hBMSCs changed during neuronal differentiation and displayed neuronlike cell appearance after 14 days' differentiation.Both hADSCs and hBMSCs were able to differentiate into neuron-like cells based on their production of neuron specific proteins including β-tubulin-Ⅲ,neuron-specific enolase (NSE),nissl bodies,and their ability to secrete brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF).Assessment of synaptop hysin and growth-associated protein-43 (GAP-43) suggested synapse structure formation in differentiated hADSCs and hBMSCs.Conclusions Our results demonstrate that hADSCs have neuronal differentiation potential similar to hBMSC,but with a higher proliferation capacity than hBMSC.Adipose tissue is abundant,easily available and would be a potential ideal

  14. Vehicular hydrogen storage using lightweight tanks (regenerative fuel cell systems)

    Energy Technology Data Exchange (ETDEWEB)

    Mitlitsky, F; Myers, B; Weisberg, A H

    1999-06-01

    Energy storage systems with extremely high specific energy (>400 Wh/kg) have been designed that use lightweight tankage to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs). Lawrence Livermore National Laboratory (LLNL) will leverage work for aerospace applications supported by other sponsors (including BMDO, NASA, and USAF) to develop URFC systems for transportation and utility applications. Lightweight tankage is important for primary fuel cell powered vehicles that use on-board storage of hydrogen. Lightweight pressure vessels with state-of-the-art performance factors were designed, and prototypes are being fabricated to meet the DOE 2000 goals (4000 Wh/kg, 12% hydrogen by weight, 700 Wh/liter, and $20/kWh in high volume production). These pressure vessels use technologies that are easily adopted by industrial partners. Advanced liners provide permeation barriers for gas storage and are mandrels for composite overwrap. URFCs are important to the efficient use of hydrogen as a transportation fuel and enabler of renewable energy. H{sub 2}/halogen URFCs may be advantageous for stationary applications whereas H{sub 2}/O{sub 2} or H{sub 2}/air URFCs are advantageous for vehicular applications. URFC research and development is required to improve performance (efficiency), reduce catalyst loading, understand engineering operation, and integrate systems. LLNL has the experimental equipment and advanced URFC membrane electrode assemblies (some with reduced catalyst loading) for evaluating commercial hardware (not funded by DOE in FY1999).

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

    Science.gov (United States)

    Araghi, Koorosh R.

    2011-01-01

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

  16. Dynamic Simulation of a Proton Exchange Membrane Fuel Cell System For Automotive Applications

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud

    2012-01-01

    A dynamic model of the PEMFC system is developed to investigate the behaviour and transient response of the fuel cell system for automotive applications. The system accounts for the fuel cell stack with coolant, humidifier, heat exchangers and pumps. Governing equations for fuel cell and humidifier...

  17. Differentiation of mammalian skeletal muscle cells cultured on microcarrier beads in a rotating cell culture system

    Science.gov (United States)

    Torgan, C. E.; Burge, S. S.; Collinsworth, A. M.; Truskey, G. A.; Kraus, W. E.

    2000-01-01

    The growth and repair of adult skeletal muscle are due in part to activation of muscle precursor cells, commonly known as satellite cells or myoblasts. These cells are responsive to a variety of environmental cues, including mechanical stimuli. The overall goal of the research is to examine the role of mechanical signalling mechanisms in muscle growth and plasticity through utilisation of cell culture systems where other potential signalling pathways (i.e. chemical and electrical stimuli) are controlled. To explore the effects of decreased mechanical loading on muscle differentiation, mammalian myoblasts are cultured in a bioreactor (rotating cell culture system), a model that has been utilised to simulate microgravity. C2C12 murine myoblasts are cultured on microcarrier beads in a bioreactor and followed throughout differentiation as they form a network of multinucleated myotubes. In comparison with three-dimensional control cultures that consist of myoblasts cultured on microcarrier beads in teflon bags, myoblasts cultured in the bioreactor exhibit an attenuation in differentiation. This is demonstrated by reduced immunohistochemical staining for myogenin and alpha-actinin. Western analysis shows a decrease, in bioreactor cultures compared with control cultures, in levels of the contractile proteins myosin (47% decrease, p < 0.01) and tropomyosin (63% decrease, p < 0.01). Hydrodynamic measurements indicate that the decrease in differentiation may be due, at least in part, to fluid stresses acting on the myotubes. In addition, constraints on aggregate size imposed by the action of fluid forces in the bioreactor affect differentiation. These results may have implications for muscle growth and repair during spaceflight.

  18. Endogenous retinoic acid activity in principal cells and intercalated cells of mouse collecting duct system.

    Directory of Open Access Journals (Sweden)

    Yuen Fei Wong

    Full Text Available BACKGROUND: Retinoic acid is the bioactive derivative of vitamin A, which plays an indispensible role in kidney development by activating retinoic acid receptors. Although the location, concentration and roles of endogenous retinoic acid in post-natal kidneys are poorly defined, there is accumulating evidence linking post-natal vitamin A deficiency to impaired renal concentrating and acidifying capacity associated with increased susceptibility to urolithiasis, renal inflammation and scarring. The aim of this study is to examine the presence and the detailed localization of endogenous retinoic acid activity in neonatal, young and adult mouse kidneys, to establish a fundamental ground for further research into potential target genes, as well as physiological and pathophysiological roles of endogenous retinoic acid in the post-natal kidneys. METHODOLOGY/PRINCIPAL FINDINGS: RARE-hsp68-lacZ transgenic mice were employed as a reporter for endogenous retinoic acid activity that was determined by X-gal assay and immunostaining of the reporter gene product, β-galactosidase. Double immunostaining was performed for β-galactosidase and markers of kidney tubules to localize retinoic acid activity. Distinct pattern of retinoic acid activity was observed in kidneys, which is higher in neonatal and 1- to 3-week-old mice than that in 5- and 8-week-old mice. The activity was present specifically in the principal cells and the intercalated cells of the collecting duct system in all age groups, but was absent from the glomeruli, proximal tubules, thin limbs of Henle's loop and distal tubules. CONCLUSIONS/SIGNIFICANCE: Endogenous retinoic acid activity exists in principal cells and intercalated cells of the mouse collecting duct system after birth and persists into adulthood. This observation provides novel insights into potential roles for endogenous retinoic acid beyond nephrogenesis and warrants further studies to investigate target genes and functions of

  19. Ho:YAG laser: intervertebral disk cell interaction using three-dimensional cell culture system

    Science.gov (United States)

    Sato, Masato; Ishihara, Miya; Arai, Tsunenori; Asazuma, Takashi; Kikuchi, Toshiyuki; Kikuchi, Makoto; Fujikawa, Kyosuke

    2000-06-01

    The purpose of this study is to evaluate the influence on the intervertebral disc cells after laser irradiation using three- dimensional culture system and to clarify the optimum Ho:YAG laser irradiation condition on percutaneous laser disc decompression (PLDD) for lumbar disc herniation. Since the Ho:YAG laser ablation is characterized by water-vapor bubble dynamics, not only thermal effect but also acoustic effect on cell metabolism might occur in the intervertebral disc. We studied the disc cell reaction from the metabolic point of view to investigate photothermal and photoacoustic effects on three-dimensional cultured disc cell. Intervertebral discs were obtained from female 30 Japanese white rabbits weighing about 1 kg. A pulsed Ho:YAG laser (wavelength: 2.1 micrometer, pulse width: about 200 microseconds) was delivered through a 200 micrometer-core diameter single silica glass fiber. We used the Ho:YAG laser irradiation fluence ranging from 60 to approximately 800 J/cm2 at the fiber end. To investigate acoustic effect, the acoustic transducer constructed with polyvinylidene fluoride (PVdF) film and acoustic absorber was used to detect the stress wave. Thermocouple and thermography were used to investigate thermal effect. Concerning damage of plasma membrane and ability of matrix synthesis, thermal effect might mainly affect cell reaction in total energy of 54 J (closed to practically used condition), but in 27 J, acoustic effect might contribute to it. We found that total energy was key parameter among the optimum condition, so that temperature and/or stress wave may influence Ho:YAG laser-disc cell interactions.

  20. Remote System Technologies for Deactivating Hanford Hot Cells

    Energy Technology Data Exchange (ETDEWEB)

    Berlin, G.; Walton, T.

    2003-02-25

    Remote system technologies are being deployed by Fluor Hanford to help accelerate the deactivation of highly-radioactive hot cell facilities. These technologies offer improved methods for accessing difficult-to-reach spaces and performing tasks such as visual inspection, radiological characterization, decontamination, waste handling, and size reduction. This paper is focused on the application of remote systems in support of deactivation work being performed in several legacy facilities at Hanford (i.e., the 324 and 327 Buildings). These facilities were previously used for fuel fabrication, materials examination, and the development of waste treatment processes. The technologies described in this paper represent significant improvements to Hanford's baseline methods, and may offer benefits to other U.S. Department of Energy (DOE) sites and commercial operations.

  1. Scaling up microbial fuel cells and other bioelectrochemical systems

    KAUST Repository

    Logan, Bruce E.

    2009-12-15

    Scientific research has advanced on different microbial fuel cell (MFC) technologies in the laboratory at an amazing pace, with power densities having reached over 1 kW/m3 (reactor volume) and to 6.9 W/m2 (anode area) under optimal conditions. The main challenge is to bring these technologies out of the laboratory and engineer practical systems for bioenergy production at larger scales. Recent advances in new types of electrodes, a better understanding of the impact of membranes and separators on performance of these systems, and results from several new pilot-scale tests are all good indicators that commercialization of the technology could be possible within a few years. Some of the newest advances and future challenges are reviewed here with respect to practical applications of these MFCs for renewable energy production and other applications. © 2009 Springer-Verlag.

  2. System Size Resonance Associated with Canard Phenomenon in a Biological Cell System

    Institute of Scientific and Technical Information of China (English)

    Juan Ma; Hong-ying Li; Zhong-huai Hou; Hou-wen Xin

    2008-01-01

    The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only yields a steady state. Also, the performance of such oscillations shows two maxima with the variation of the system size, indicating the occurrence of system size resonance. This behavior is found to be intimately connected with the canard phenomenon. Interestingly, it is also found that one of the optimal system sizes matches well with the real cell size, and such a match is robust to the variation of the control parameters.

  3. Functional Genomic Analysis of Systemic Cell Division Regulation in Legumes

    International Nuclear Information System (INIS)

    Legumes develop root nodules from pluripotent stem cells in the root pericycle in response to mitogenic activation by a decorated chitin-like nodulation factor synthesized in Rhizobium bacteria. The soybean genes encoding the receptor for such signals were cloned using map-based cloning approaches. Pluripotent cells in the root pericycle and the outer or inner cortex undergo repeated cell divisions to initiate a composite nodule primordium that develops to a functional nitrogen-fixing nodule. The process itself is autoregulated, leading to the characteristic nodulation of the upper root system. Autoregulation of nodulation (AON) in all legumes is controlled in part by a leucine-rich repeat receptor kinase gene (GmNARK). Mutations of GmNARK, and its other legume orthologues, result in abundant nodulation caused by the loss of a yet-undefined negative nodulation repressor system. AON receptor kinases are involved in perception of a long distance, root-derived signal, to negatively control nodule proliferation. GmNARK and LjHAR1 are expressed in phloem parenchyma. GmNARK kinase domain interacts with Kinase Associated Protein Phosphatase (KAPP). NARK gene expression did not mirror biological NARK activity in nodulation control, as q-RT-PCR in soybean revealed high NARK expression in roots, root tips, leaves, petioles, stems and hypocotyls, while shoot and root apical meristems were devoid of NARK RNA. High through-put transcript analysis in soybean leaf and root indicated that major genes involved in JA synthesis or response are preferentially down-regulated in leaf but not root of wild type, but not NARK mutants, suggesting that AON signaling may in part be controlled by events relating to hormone metabolism. Ethylene and abscisic acid insensitive mutants of L. japonicus are described. Nodulation in legumes has significance to global economies and ecologies, as the nitrogen input into the biosphere allows food, feed and biofuel production without the inherent costs

  4. Novel electrical energy storage system based on reversible solid oxide cells: System design and operating conditions

    Science.gov (United States)

    Wendel, C. H.; Kazempoor, P.; Braun, R. J.

    2015-02-01

    Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges and questions from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. This paper presents a novel system based on ReSOCs that employ a thermal management strategy of promoting exothermic methanation within the ReSOC cell-stack to provide thermal energy for the endothermic steam/CO2 electrolysis reactions during charging mode (fuel producing). This approach also serves to enhance the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a physically based ReSOC stack model coupled with thermodynamic system component models. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (680 °C) and elevated stack pressure (20 bar). The optimal operating condition arises from a tradeoff between stack efficiency and auxiliary power requirements from balance of plant hardware.

  5. Criticality computations for CANDU - 6 cell utilizing the SCALE system

    International Nuclear Information System (INIS)

    The investigated CANDU - 6 cell was defined in the frame of a benchmark approach; the fuel pellets were of sintered UO2 (with natural uranium), the coolant and moderator are D2O of different purities, while the fuel element can, the pressure tube and the calandria are made of different zirconium based alloys. Utilising the modular system of SCALE codes for criticality computation in CANDU reactor is challenging from both the computation method (Monte Carlo) used and the nuclear data used, which are not specific to the CANDU reactor. For criticality computation the SAS1 (NITAWL, BONAMI, and KENO - VI modules) sequence of the SCALE system. The geometrical model used was is the one indicated in benchmark approach corresponding to the Final Safety Report for Cernavoda NPP Unit 1. Separate calculation with three nuclear data libraries were performed in order to evidence the influence of energy cutting (27, 44 and 238 groups, respectively) and of the nuclear data provenance. Sensitivity calculations aimed at investigating the influence of small variations in geometrical parameters and composition on the effective multiplication factor. Also, different variants of treating the leaks, ranging from the completely reflected cell up to the infinite lattice were studied

  6. FAS system deregulation in T-cell lymphoblastic lymphoma.

    Science.gov (United States)

    Villa-Morales, M; Cobos, M A; González-Gugel, E; Álvarez-Iglesias, V; Martínez, B; Piris, M A; Carracedo, A; Benítez, J; Fernández-Piqueras, J

    2014-01-01

    The acquisition of resistance towards FAS-mediated apoptosis may be required for tumor formation. Tumors from various histological origins exhibit FAS mutations, the most frequent being hematological malignancies. However, data regarding FAS mutations or FAS signaling alterations are still lacking in precursor T-cell lymphoblastic lymphomas (T-LBLs). The available data on acute lymphoblastic leukemia, of precursor origin as well, indicate a low frequency of FAS mutations but often report a serious reduction in FAS-mediated apoptosis as well as chemoresistance, thus suggesting the occurrence of mechanisms able to deregulate the FAS signaling pathway, different from FAS mutation. Our aim at this study was to determine whether FAS-mediated apoptotic signaling is compromised in human T-LBL samples and the mechanisms involved. This study on 26 T-LBL samples confirms that the FAS system is impaired to a wide extent in these tumors, with 57.7% of the cases presenting any alteration of the pathway. A variety of mechanisms seems to be involved in such alteration, in order of frequency the downregulation of FAS, the deregulation of other members of the pathway and the occurrence of mutations at FAS. Considering these results together, it seems plausible to think of a cumulative effect of several alterations in each T-LBL, which in turn may result in FAS/FASLG system deregulation. Since defective FAS signaling may render the T-LBL tumor cells resistant to apoptotic cell death, the correct prognosis, diagnosis and thus the success of anticancer therapy may require such an in-depth knowledge of the complete scenario of FAS-signaling alterations. PMID:24603338

  7. Development of an Integrated Microfluidic Perfusion Cell Culture System for Real-Time Microscopic Observation of Biological Cells

    OpenAIRE

    Chih-Chin Oh-Yang; Min-Hsien Wu; Jr-Lung Lin; Shih-Siou Wang

    2011-01-01

    This study reports an integrated microfluidic perfusion cell culture system consisting of a microfluidic cell culture chip, and an indium tin oxide (ITO) glass-based microheater chip for micro-scale perfusion cell culture, and its real-time microscopic observation. The system features in maintaining both uniform, and stable chemical or thermal environments, and providing a backflow-free medium pumping, and a precise thermal control functions. In this work, the performance of the medium pumpin...

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

    Energy Technology Data Exchange (ETDEWEB)

    Gerdes, Kirk; Richards, George

    2014-04-16

    data capturing operational degradation. The data were matched by a 3D multi-physics simulation of SOFC operational performance assuming that the entire performance loss related to coarsening of the cathode triple phase boundary (3PB). The predicted 3PB coarsening was then used to tune the mobility parameters of a phase field model describing microstructural evolution of the lanthanum strontium manganate (LSM)/ yttria stabilized zirconia (YSZ) system. Once calibrated, the phase field model predicted continuous microstructural coarsening processes occurring over the operating period, which could be extrapolated to performance periods of longer duration and also used to produce 3D graphical representations. NETL researchers also completed significant electrode engineering research complimented by 3D multi-physics simulations. In one key activity researchers generated an illustration demonstrating that control of infiltrate deposition can provide cell manufacturers with significant additional operational and engineering control over the SOFC stack. Specifically, researchers demonstrated that by engineering the deposition of electrocatalyst inside the cathode, the distribution of overpotential across the cell could be controlled to either decrease the average cell overpotential value or minimize cross-cell overpotential gradient. Results imply that manufacturers can establish improved engineering control over stack operation by implementing infiltration technology in SOFC cathodes.

  9. A Robot-Assisted Cell Manipulation System with an Adaptive Visual Servoing Method

    OpenAIRE

    Yu Xie; Feng Zeng; Wenming Xi; Yunlei Zhou; Houde Liu; Mingliang Chen

    2016-01-01

    Robot-assisted cell manipulation is gaining attention for its ability in providing high throughput and high precision cell manipulation for the biological industry. This paper presents a visual servo microrobotic system for cell microinjection. We investigated the automatic cell autofocus method that reduced the complexity of the system. Then, we produced an adaptive visual processing algorithm to detect the location of the cell and micropipette toward the uneven illumination problem. Fourtee...

  10. Sliding Mode Control of the Battery Bank for the Fuel Cell-based Distributed Generation System

    OpenAIRE

    Junsheng Jiao

    2013-01-01

    The dynamic models for the fuel cell power and the configuration of the fuel cell distributed generation system are shown in this paper. Due to nonlinear characteristics of fuel cell model, the output voltage of fuel cell varies greatly when the load changes. A novel interface is designed to provide a constant output voltage for charging of the battery bank of the fuel cell distributed generation. The thesis presents a sliding mode control design of PEMFC distributed generation system. A casc...

  11. POSSUM escore como preditor de mortalidade em pacientes cirúrgicos Utilizacion del puntaje POSSUM como indicador de la mortalidad en pacientes quirúrgicos POSSUM scoring system for predicting mortality in surgical patients

    OpenAIRE

    Adriana Cristina Galbiatti Parminondi Elias; Tiemi Matsuo; Cíntia Magalhães Carvalho Grion; Lucienne Tibery Queiroz Cardoso; Paulo Henrique Verri

    2009-01-01

    O estudo avaliou a utilização do escore POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity) para predizer a mortalidade na prática cirúrgica.Foram analisados 416 pacientes cirúrgicos com internação na UTI para cuidados de pós-operatório. Foram realizadas comparações entre as taxas de mortalidade predita e observada de acordo com 4 grupos de risco: 0-4%, 5-14%, 15-49%, 50% ou mais, e calculada a área sob a curva ROC do escore POSSUM e APACHE II para a...

  12. POSSUM escore como preditor de mortalidade em pacientes cirúrgicos Utilizacion del puntaje POSSUM como indicador de la mortalidad en pacientes quirúrgicos POSSUM scoring system for predicting mortality in surgical patients

    Directory of Open Access Journals (Sweden)

    Adriana Cristina Galbiatti Parminondi Elias

    2009-03-01

    Full Text Available O estudo avaliou a utilização do escore POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity para predizer a mortalidade na prática cirúrgica.Foram analisados 416 pacientes cirúrgicos com internação na UTI para cuidados de pós-operatório. Foram realizadas comparações entre as taxas de mortalidade predita e observada de acordo com 4 grupos de risco: 0-4%, 5-14%, 15-49%, 50% ou mais, e calculada a área sob a curva ROC do escore POSSUM e APACHE II para a mortalidade. A taxa de mortalidade foi de 22,4%. O escores POSSUM e APACHE II superestimaram o risco de morte, e a área sob a curva ROC do POSSUM foi de 0,762 e a do APACHE II de 0,737, sugerindo a utilização do POSSUM como ferramenta auxiliar na predição de risco de morte em pacientes cirúrgicos.El estudio evaluó la utilización del puntaje POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbity para predecir la mortalidad en la práctica quirúrgica. Fueron analizados 416 pacientes quirúrgicos internados en la UTI para cuidados postoperatorios. Fueron realizadas comparaciones entre las tasas de mortalidad estimada y observada, de acuerdo con 4 grupos de riesgo: 0-4%, 5-14%, 15-49%, 50% o más, y calculada el área debajo de la curva ROC del puntaje POSSUM y APACHE II para la mortalidad. La tasa de mortalidad fue de 2,4%. Los puntajes POSSUM y APACHE II superestimaron el riesgo de muerte, y el área debajo de la curva ROC del POSSUM fue de 0,762 y la del APACHE II de 0,737, lo que sugiere la utilización del POSSUM como herramienta auxiliar en la predicción de riesgo de muerte en pacientes quirúrgicos.This study evaluated the use of the POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity score for predicting mortality in surgical practice. In this study, 416 surgical patients admitted into ICUs for post-surgical care were analyzed. Both predicted and actual mortality rates were compared, according to four risk groups: 0-4%, 5-14%, 15-49%, 50% and over, and the area under the ROC curve of the POSSUM and APACHE II for mortality. The POSSUM and APACHE II scores overestimated the risk of death. The area under the ROC curve of the POSSUM was 0.762, and under APACHE II was 0.737, suggesting the use of POSSUM as an auxiliary tool to predict the risk of death in surgical patients.

  13. Enhanced Expression of Bruton's Tyrosine Kinase in B Cells Drives Systemic Autoimmunity by Disrupting T Cell Homeostasis.

    Science.gov (United States)

    Corneth, Odilia B J; de Bruijn, Marjolein J W; Rip, Jasper; Asmawidjaja, Patrick S; Kil, Laurens P; Hendriks, Rudi W

    2016-07-01

    Upon BCR stimulation, naive B cells increase protein levels of the key downstream signaling molecule Bruton's tyrosine kinase (BTK). Transgenic CD19-hBtk mice with B cell-specific BTK overexpression show spontaneous germinal center formation, anti-nuclear autoantibodies, and systemic autoimmunity resembling lupus and Sjögren syndrome. However, it remains unknown how T cells are engaged in this pathology. In this study, we found that CD19-hBtk B cells were high in IL-6 and IL-10 and disrupted T cell homeostasis in vivo. CD19-hBtk B cells promoted IFN-γ production by T cells and expression of the immune-checkpoint protein ICOS on T cells and induced follicular Th cell differentiation. Crosses with CD40L-deficient mice revealed that increased IL-6 production and autoimmune pathology in CD19-hBtk mice was dependent on B-T cell interaction, whereas IL-10 production and IgM autoantibody formation were CD40L independent. Surprisingly, in Btk-overexpressing mice, naive B cells manifested increased CD86 expression, which was dependent on CD40L, suggesting that T cells interact with B cells in a very early stage of immune pathology. These findings indicate that increased BTK-mediated signaling in B cells involves a positive-feedback loop that establishes T cell-propagated autoimmune pathology, making BTK an attractive therapeutic target in autoimmune disease. PMID:27226091

  14. Photoelectrochemical cells based on photosynthetic systems: a review

    Directory of Open Access Journals (Sweden)

    Roman A. Voloshin

    2015-06-01

    Full Text Available Photosynthesis is a process which converts light energy into energy contained in the chemical bonds of organic compounds by photosynthetic pigments such as chlorophyll (Chl a, b, c, d, f or bacteriochlorophyll. It occurs in phototrophic organisms, which include higher plants and many types of photosynthetic bacteria, including cyanobacteria. In the case of the oxygenic photosynthesis, water is a donor of both electrons and protons, and solar radiation serves as inexhaustible source of energy. Efficiency of energy conversion in the primary processes of photosynthesis is close to 100%. Therefore, for many years photosynthesis has attracted the attention of researchers and designers looking for alternative energy systems as one of the most efficient and eco-friendly pathways of energy conversion. The latest advances in the design of optimal solar cells include the creation of converters based on thylakoid membranes, photosystems, and whole cells of cyanobacteria immobilized on nanostructured electrode (gold nanoparticles, carbon nanotubes, nanoparticles of ZnO and TiO2. The mode of solar energy conversion in photosynthesis has a great potential as a source of renewable energy while it is sustainable and environmentally safety as well. Application of pigments such as Chl f and Chl d (unlike Chl a and Chl b, by absorbing the far red and near infrared region of the spectrum (in the range 700-750 nm, will allow to increase the efficiency of such light transforming systems. This review article presents the last achievements in the field of energy photoconverters based on photosynthetic systems.

  15. Chromophore maturation and fluorescence fluctuation spectroscopy of fluorescent proteins in a cell-free expression system

    OpenAIRE

    Macdonald, Patrick J.; Chen, Yan; Mueller, Joachim D.

    2011-01-01

    Cell-free synthesis, a method for the rapid expression of proteins, is increasingly used to study interactions of complex biological systems. GFP and its variants have become indispensable for fluorescence studies in live cells and are equally attractive as reporters for cell-free systems. This work investigates the use of fluorescence fluctuation spectroscopy (FFS) as a tool for quantitative analysis of protein interactions in cell-free expression systems. We also explore chromophore maturat...

  16. Murine and Human Model Systems for the Study of Dendritic Cell Immunobiology.

    Science.gov (United States)

    Hargadon, Kristian M

    2016-03-01

    Dendritic cells are a population of innate immune cells that possess their own effector functions as well as numerous regulatory properties that shape the activity of other innate and adaptive cells of the immune system. Following their development from either lymphoid or myeloid progenitors, the function of dendritic cells is tightly linked to their maturation and activation status. Differentiation into specialized subsets of dendritic cells also contributes to the diverse immunologic functions of these cells. Because of the key role played by dendritic cells in the regulation of both immune tolerance and activation, significant efforts have been focused on understanding dendritic cell biology. This review highlights the model systems currently available to study dendritic cell immunobiology and emphasizes the advantages and disadvantages to each system in both murine and human settings. In particular, in vitro cell culture systems involving immortalized dendritic cell lines, ex vivo systems for differentiating and expanding dendritic cells from their precursor populations, and systems for expanding, ablating, and manipulating dendritic cells in vivo are discussed. Emphasis is placed on the contribution of these systems to our current understanding of the development, function, and immunotherapeutic applications of dendritic cells, and insights into how these models might be extended in the future to answer remaining questions in the field are discussed. PMID:25203775

  17. Establishment of automated culture system for murine induced pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Koike Hiroyuki

    2012-11-01

    Full Text Available Abstract Background Induced pluripotent stem (iPS cells can differentiate into any cell type, which makes them an attractive resource in fields such as regenerative medicine, drug screening, or in vitro toxicology. The most important prerequisite for these industrial applications is stable supply and uniform quality of iPS cells. Variation in quality largely results from differences in handling skills between operators in laboratories. To minimize these differences, establishment of an automated iPS cell culture system is necessary. Results We developed a standardized mouse iPS cell maintenance culture, using an automated cell culture system housed in a CO2 incubator commonly used in many laboratories. The iPS cells propagated in a chamber uniquely designed for automated culture and showed specific colony morphology, as for manual culture. A cell detachment device in the system passaged iPS cells automatically by dispersing colonies to single cells. In addition, iPS cells were passaged without any change in colony morphology or expression of undifferentiated stem cell markers during the 4 weeks of automated culture. Conclusions Our results show that use of this compact, automated cell culture system facilitates stable iPS cell culture without obvious effects on iPS cell pluripotency or colony-forming ability. The feasibility of iPS cell culture automation may greatly facilitate the use of this versatile cell source for a variety of biomedical applications.

  18. Compact Electro-Permeabilization System for Controlled Treatment of Biological Cells and Cell Medium Conductivity Change Measurement

    Directory of Open Access Journals (Sweden)

    Novickij Vitalij

    2014-10-01

    Full Text Available Subjection of biological cells to high intensity pulsed electric field results in the permeabilization of the cell membrane. Measurement of the electrical conductivity change allows an analysis of the dynamics of the process, determination of the permeabilization thresholds, and ion efflux influence. In this work a compact electro-permeabilization system for controlled treatment of biological cells is presented. The system is capable of delivering 5 μs - 5 ms repetitive square wave electric field pulses with amplitude up to 1 kV. Evaluation of the cell medium conductivity change is implemented in the setup, allowing indirect measurement of the ion concentration changes occurring due to the cell membrane permeabilization. The simulation model using SPICE and the experimental data of the proposed system are presented in this work. Experimental data with biological cells is also overviewed

  19. Inexpensive remote video surveillance system with microcomputer and solar cells

    International Nuclear Information System (INIS)

    A low-cost prototype is developed with a RPI plate for remote video surveillance. Additionally, the theoretical basis to provide energy independence have developed through solar cells and a battery bank. Some existing commercial monitoring systems are studied and analyzed, components such as: cameras, communication devices (WiFi and 3G), free software packages for video surveillance, control mechanisms and theory remote photovoltaic systems. A number of steps are developed to implement the module and install, configure and test each of the elements of hardware and software that make up the module, exploring the feasibility of providing intelligence to the system using the software chosen. Events that have been generated by motion detection have been simple, intuitive way to view, archive and extract. The implementation of the module by a microcomputer video surveillance and motion detection software (Zoneminder) has been an option for a lot of potential; as the platform for monitoring and recording data has provided all the tools to make a robust and secure surveillance. (author)

  20. A Robot-Assisted Cell Manipulation System with an Adaptive Visual Servoing Method

    Directory of Open Access Journals (Sweden)

    Yu Xie

    2016-06-01

    Full Text Available Robot-assisted cell manipulation is gaining attention for its ability in providing high throughput and high precision cell manipulation for the biological industry. This paper presents a visual servo microrobotic system for cell microinjection. We investigated the automatic cell autofocus method that reduced the complexity of the system. Then, we produced an adaptive visual processing algorithm to detect the location of the cell and micropipette toward the uneven illumination problem. Fourteen microinjection experiments were conducted with zebrafish embryos. A 100% success rate was achieved either in autofocus or embryo detection, which verified the robustness of the proposed automatic cell manipulation system.

  1. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    Directory of Open Access Journals (Sweden)

    Ivana Stevanovic

    2015-09-01

    Full Text Available Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes – catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and •O2- production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells.

  2. Bioluminescent system for dynamic imaging of cell and animal behavior

    International Nuclear Information System (INIS)

    Highlights: ► We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. ► ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. ► ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. ► ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

  3. Bioluminescent system for dynamic imaging of cell and animal behavior

    Energy Technology Data Exchange (ETDEWEB)

    Hara-Miyauchi, Chikako [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Tsuji, Osahiko [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Hanyu, Aki [Division of Biochemistry, The Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo 135-8550 (Japan); Okada, Seiji [Department of Advanced Medical Initiatives, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan); Yasuda, Akimasa [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Fukano, Takashi [Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Akazawa, Chihiro [Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Nakamura, Masaya [Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Imamura, Takeshi [Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan); Core Research for Evolutional Science and Technology, The Japan Science and Technology Corporation, Tokyo 135-8550 (Japan); Matsuzaki, Yumi [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Okano, Hirotaka James, E-mail: hjokano@jikei.ac.jp [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Division of Regenerative Medicine Jikei University School of Medicine, Tokyo 150-8461 (Japan); and others

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. Black-Right-Pointing-Pointer ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. Black-Right-Pointing-Pointer ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. Black-Right-Pointing-Pointer ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

  4. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    Science.gov (United States)

    Bozic, Iva; Savic, Danijela; Stevanovic, Ivana; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate) possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes—catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and ·O−2 production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells. PMID:26388737

  5. Process engineering of ceramic composite coatings for fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Kim, H.; Chen, M.; Yang, Q.; Troczynski, T. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Metals and Materials Engineering

    2003-07-01

    Researchers at UBCeram at the Department of Metals and Materials Engineering at the University of British Columbia have developed a technology to chemically bond composite sol-gel (CB-CSG) coating onto metallic surfaces of complex or concave shapes. The process has been optimized for electrically resistive coatings and corrosion-resistant coatings. The CSG is sprayed onto metallic surfaces and is heat-treated at 300 degrees C to partially dehydrate the hydroxides. The CSG film is then chemically bonded through reaction of active alumina with metal phosphates, such as aluminium phosphate. A new chromate-free process is being developed to address the issue of coatings porosity. The electrodeposition technique involves polymer particles mixed with suspended fine alumina particles which are co-deposited by electrophoretic means or by electrocoagulation. The composite e-coatings have excellent mechanical properties and are being considered as a protective coating for various components of fuel cell systems. 9 refs., 7 figs.

  6. Lipid membrane domains in cell surface and vacuolar systems.

    Science.gov (United States)

    Kobayashi, T; Hirabayashi, Y

    2000-01-01

    Detergent insoluble sphingolipid-cholesterol enriched 'raft'-like membrane microdomains have been implicated in a variety of biological processes including sorting, trafficking, and signaling. Mutant cells and knockout animals of sphingolipid biosynthesis are clearly useful to understand the biological roles of lipid components in raft-like domains. It is suggested that raft-like domains distribute in internal vacuolar membranes as well as plasma membranes. In addition to sphingolipid-cholesterol-rich membrane domains, recent studies suggest the existence of another lipid-membrane domain in the endocytic pathway. This domain is enriched with a unique phospholipid, lysobisphosphatidic acid (LBPA) and localized in the internal membrane of multivesicular endosome. LBPA-rich membrane domains are involved in lipid and protein sorting within the endosomal system. Possible interaction between sphingolipids and LBPA in sphingolipid-storage disease is discussed. PMID:11201787

  7. Model system for plant cell biology: GFP imaging in living onion epidermal cells

    Science.gov (United States)

    Scott, A.; Wyatt, S.; Tsou, P. L.; Robertson, D.; Allen, N. S.

    1999-01-01

    The ability to visualize organelle localization and dynamics is very useful in studying cellular physiological events. Until recently, this has been accomplished using a variety of staining methods. However, staining can give inaccurate information due to nonspecific staining, diffusion of the stain or through toxic effects. The ability to target green fluorescent protein (GFP) to various organelles allows for specific labeling of organelles in vivo. The disadvantages of GFP thus far have been the time and money involved in developing stable transformants or maintaining cell cultures for transient expression. In this paper, we present a rapid transient expression system using onion epidermal peels. We have localized GFP to various cellular compartments (including the cell wall) to illustrate the utility of this method and to visualize dynamics of these compartments. The onion epidermis has large, living, transparent cells in a monolayer, making them ideal for visualizing GFP. This method is easy and inexpensive, and it allows for testing of new GFP fusion proteins in a living tissue to determine deleterious effects and the ability to express before stable transformants are attempted.

  8. Modeling and control of the output current of a Reformed Methanol Fuel Cell system

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Pasupathi, Sivakumar;

    2015-01-01

    In this work, a dynamic Matlab SIMULINK model of the relationship between the fuel cell current set point of a Reformed Methanol Fuel Cell system and the output current of the system is developed. The model contains an estimated fuel cell model, based on a polarization curve and assumed first order...

  9. Dynamic characteristics of an automotive fuel cell system for transitory load changes

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud

    2013-01-01

    A dynamic model of Polymer Electrolyte Membrane Fuel Cell (PEMFC) system is developed to investigate the behavior and transient response of a fuel cell system for automotive applications. Fuel cell dynamics are subjected to reactant flows, heat management and water transportation inside the fuel...

  10. Cell adhesion molecules in the central nervous system

    OpenAIRE

    Togashi, Hideru; Sakisaka, Toshiaki; Takai, Yoshimi

    2009-01-01

    Cell-cell adhesion molecules play key roles at the intercellular junctions of a wide variety of cells, including interneuronal synapses and neuron-glia contacts. Functional studies suggest that adhesion molecules are implicated in many aspects of neural network formation, such as axon-guidance, synapse formation, regulation of synaptic structure and astrocyte-synapse contacts. Some basic cell biological aspects of the assembly of junctional complexes of neurons and glial cells resemble those ...

  11. Development of Scalable Culture Systems for Human Embryonic Stem Cells

    OpenAIRE

    Azarin, Samira M.; Palecek, Sean P.

    2010-01-01

    The use of human pluripotent stem cells, including embryonic and induced pluripotent stem cells, in therapeutic applications will require the development of robust, scalable culture technologies for undifferentiated cells. Advances made in large-scale cultures of other mammalian cells will facilitate expansion of undifferentiated human embryonic stem cells (hESCs), but challenges specific to hESCs will also have to be addressed, including development of defined, humanized culture media and su...

  12. Optimization of cell line development in the GS-CHO expression system using a high-throughput, single cell-based clone selection system.

    Science.gov (United States)

    Nakamura, Tsuyoshi; Omasa, Takeshi

    2015-09-01

    Therapeutic antibodies are commonly produced by high-expressing, clonal and recombinant Chinese hamster ovary (CHO) cell lines. Currently, CHO cells dominate as a commercial production host because of their ease of use, established regulatory track record, and safety profile. CHO-K1SV is a suspension, protein-free-adapted CHO-K1-derived cell line employing the glutamine synthetase (GS) gene expression system (GS-CHO expression system). The selection of high-producing mammalian cell lines is a crucial step in process development for the production of therapeutic antibodies. In general, cloning by the limiting dilution method is used to isolate high-producing monoclonal CHO cells. However, the limiting dilution method is time consuming and has a low probability of monoclonality. To minimize the duration and increase the probability of obtaining high-producing clones with high monoclonality, an automated single cell-based clone selector, the ClonePix FL system, is available. In this study, we applied the high-throughput ClonePix FL system for cell line development using CHO-K1SV cells and investigated efficient conditions for single cell-based clone selection. CHO-K1SV cell growth at the pre-picking stage was improved by optimizing the formulation of semi-solid medium. The efficiency of picking and cell growth at the post-picking stage was improved by optimization of the plating time without decreasing the diversity of clones. The conditions for selection, including the medium formulation, were the most important factors for the single cell-based clone selection system to construct a high-producing CHO cell line. PMID:25792187

  13. Culturing Human Pluripotent and Neural Stem Cells in an Enclosed Cell Culture System for Basic and Preclinical Research

    Science.gov (United States)

    Stover, Alexander E.; Herculian, Siranush; Banuelos, Maria G.; Navarro, Samantha L.; Jenkins, Michael P.; Schwartz, Philip H.

    2016-01-01

    This paper describes how to use a custom manufactured, commercially available enclosed cell culture system for basic and preclinical research. Biosafety cabinets (BSCs) and incubators have long been the standard for culturing and expanding cell lines for basic and preclinical research. However, as the focus of many stem cell laboratories shifts from basic research to clinical translation, additional requirements are needed of the cell culturing system. All processes must be well documented and have exceptional requirements for sterility and reproducibility. In traditional incubators, gas concentrations and temperatures widely fluctuate anytime the cells are removed for feeding, passaging, or other manipulations. Such interruptions contribute to an environment that is not the standard for cGMP and GLP guidelines. These interruptions must be minimized especially when cells are utilized for therapeutic purposes. The motivation to move from the standard BSC and incubator system to a closed system is that such interruptions can be made negligible. Closed systems provide a work space to feed and manipulate cell cultures and maintain them in a controlled environment where temperature and gas concentrations are consistent. This way, pluripotent and multipotent stem cells can be maintained at optimum health from the moment of their derivation all the way to their eventual use in therapy. PMID:27341536

  14. Using single cell cultivation system for on-chip monitoring of the interdivision timer in Chlamydomonas reinhardtii cell cycle

    Directory of Open Access Journals (Sweden)

    Soloviev Mikhail

    2010-09-01

    Full Text Available Abstract Regulation of cell cycle progression in changing environments is vital for cell survival and maintenance, and different regulation mechanisms based on cell size and cell cycle time have been proposed. To determine the mechanism of cell cycle regulation in the unicellular green algae Chlamydomonas reinhardtii, we developed an on-chip single-cell cultivation system that allows for the strict control of the extracellular environment. We divided the Chlamydomonas cell cycle into interdivision and division phases on the basis of changes in cell size and found that, regardless of the amount of photosynthetically active radiation (PAR and the extent of illumination, the length of the interdivision phase was inversely proportional to the rate of increase of cell volume. Their product remains constant indicating the existence of an 'interdivision timer'. The length of the division phase, in contrast, remained nearly constant. Cells cultivated under light-dark-light conditions did not divide unless they had grown to twice their initial volume during the first light period. This indicates the existence of a 'commitment sizer'. The ratio of the cell volume at the beginning of the division phase to the initial cell volume determined the number of daughter cells, indicating the existence of a 'mitotic sizer'.

  15. Metabolic response of lung cancer cells to radiation in a paper-based 3D cell culture system.

    Science.gov (United States)

    Simon, Karen A; Mosadegh, Bobak; Minn, Kyaw Thu; Lockett, Matthew R; Mohammady, Marym R; Boucher, Diane M; Hall, Amy B; Hillier, Shawn M; Udagawa, Taturo; Eustace, Brenda K; Whitesides, George M

    2016-07-01

    This work demonstrates the application of a 3D culture system-Cells-in-Gels-in-Paper (CiGiP)-in evaluating the metabolic response of lung cancer cells to ionizing radiation. The 3D tissue-like construct-prepared by stacking multiple sheets of paper containing cell-embedded hydrogels-generates a gradient of oxygen and nutrients that decreases monotonically in the stack. Separating the layers of the stack after exposure enabled analysis of the cellular response to radiation as a function of oxygen and nutrient availability; this availability is dictated by the distance between the cells and the source of oxygenated medium. As the distance between the cells and source of oxygenated media increased, cells show increased levels of hypoxia-inducible factor 1-alpha, decreased proliferation, and reduced sensitivity to ionizing radiation. Each of these cellular responses are characteristic of cancer cells observed in solid tumors. With this setup we were able to differentiate three isogenic variants of A549 cells based on their metabolic radiosensitivity; these three variants have known differences in their metastatic behavior in vivo. This system can, therefore, capture some aspects of radiosensitivity of populations of cancer cells related to mass-transport phenomenon, carry out systematic studies of radiation response in vitro that decouple effects from migration and proliferation of cells, and regulate the exposure of oxygen to subpopulations of cells in a tissue-like construct either before or after irradiation. PMID:27116031

  16. Fault tolerance control for proton exchange membrane fuel cell systems

    Science.gov (United States)

    Wu, Xiaojuan; Zhou, Boyang

    2016-08-01

    Fault diagnosis and controller design are two important aspects to improve proton exchange membrane fuel cell (PEMFC) system durability. However, the two tasks are often separately performed. For example, many pressure and voltage controllers have been successfully built. However, these controllers are designed based on the normal operation of PEMFC. When PEMFC faces problems such as flooding or membrane drying, a controller with a specific design must be used. This paper proposes a unique scheme that simultaneously performs fault diagnosis and tolerance control for the PEMFC system. The proposed control strategy consists of a fault diagnosis, a reconfiguration mechanism and adjustable controllers. Using a back-propagation neural network, a model-based fault detection method is employed to detect the PEMFC current fault type (flooding, membrane drying or normal). According to the diagnosis results, the reconfiguration mechanism determines which backup controllers to be selected. Three nonlinear controllers based on feedback linearization approaches are respectively built to adjust the voltage and pressure difference in the case of normal, membrane drying and flooding conditions. The simulation results illustrate that the proposed fault tolerance control strategy can track the voltage and keep the pressure difference at desired levels in faulty conditions.

  17. Particle in cell simulations of beam plasma system

    International Nuclear Information System (INIS)

    The propagation of relativistic electron beam in dense plasma is studied with the help of Particle in Cell simulations for both 2D and 3D configurations. The background plasma system provides for the return currents balancing the beam current. These two current systems are unstable to Weibel destabilization as a result of which the forward and return currents separate spatially. This leads to the generation of magnetic fields. The present paper focuses on the study of the spatial and temporal profiles of the generated magnetic fields. In the normal case of infinite and/or periodic simulation box with homogeneous plasma density the observed magnetic field dominates at the scale length of skin depth. The role of plasma density inhomogeneity and the finite transverse width of the beam electrons are investigated in the work. It is shown that when the plasma density inhomogeneity with scales sharper than the skin depth is chosen, the magnetic field structures with similar short scales form. It is also observed that when the beam width is finite magnetic fields with structures at the scale length of beam width form. (author)

  18. Application of the identification methods from Hilbert and Prony to the study of oscillatory phenomena in electrical power systems; Aplicacion de los metodos de identificacion de Hilbert y Prony al estudio de fenomenos oscilatorios en sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Andrade Soto, Manuel Antonio

    2002-10-15

    In the present thesis work the application of identification techniques is investigated based on methods of spectral analysis to the study of the instantaneous characteristics of signals obtained by means of digital simulation of the dynamic behavior of the power system. The study focuses on the perspectives developed from two different approaches of analysis: the use of lineal methods of spectral analysis and the use of methods of non-lineal analysis, based on the concept of an analytical signal. The developed tools are applied to the study of two phenomena of electromechanical origin of different characteristics in complex power systems. A comparison between the results obtained is performed for these techniques and the possibility of its application is discussed for the problem of on-line identification in power systems. [Spanish] En el presente trabajo de tesis se investiga la aplicacion de tecnicas de identificacion basadas en metodos de analisis espectral al estudio de las caracteristicas instantaneas de senales obtenidas mediante simulacion digital del comportamiento dinamico del sistema de potencia. El estudio se centra en las aproximaciones desarrolladas desde dos enfoques distintos de analisis: la utilizacion de metodos lineales de analisis espectral y la utilizacion de metodos de analisis no lineal, basados en el concepto de una senal analitica. Las herramientas desarrolladas se aplican al estudio de dos fenomenos de origen electromecanico de caracteristicas distintas en sistemas complejos de potencia. Se hace una comparacion entre los resultados obtenidos por estas tecnicas y se discute la posibilidad de su aplicacion al problema de identificacion en linea en sistemas de potencia.

  19. Non-Flow-Through Fuel Cell System Test Results and Demonstration on the SCARAB Rover

    Science.gov (United States)

    Scheidegger, Brianne, T.; Burke, Kenneth A.; Jakupca, Ian J.

    2012-01-01

    This paper describes the results of the demonstration of a non-flow-through PEM fuel cell as part of a power system on the SCARAB rover. A 16-cell non-flow-through fuel cell stack from Infinity Fuel Cell and Hydrogen, Inc. was incorporated into a power system designed to act as a range extender by providing power to the rover s hotel loads. This work represents the first attempt at a ground demonstration of this new technology aboard a mobile test platform. Development and demonstration were supported by the Office of the Chief Technologist s Space Power Systems Project and the Advanced Exploration System Modular Power Systems Project.

  20. Zika Kills Vital Nervous System Cells in Adult Mice, Study Finds

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160505.html Zika Kills Vital Nervous System Cells in Adult Mice, ... 2016 THURSDAY, Aug. 18, 2016 (HealthDay News) -- The Zika virus kills neural stem cells in the brains ...

  1. Control assembly for controlling a fuel cell system during shutdown and restart

    Science.gov (United States)

    Venkataraman, Ramki; Berntsen, George; Carlson, Glenn L.; Farooque, Mohammad; Beachy, Dan; Peterhans, Stefan; Bischoff, Manfred

    2010-06-15

    A fuel cell system and method in which the fuel cell system receives and an input oxidant gas and an input fuel gas, and in which a fuel processing assembly is provided and is adapted to at least humidify the input fuel gas which is to be supplied to the anode of the fuel cell of the system whose cathode receives the oxidant input gas via an anode oxidizing assembly which is adapted to couple the output of the anode of the fuel cell to the inlet of the cathode of the fuel cell during normal operation, shutdown and restart of the fuel cell system, and in which a control assembly is further provided and is adapted to respond to shutdown of the fuel cell system during which input fuel gas and input oxidant gas cease to be received by the fuel cell system, the control assembly being further adapted to, when the fuel cell system is shut down: control the fuel cell system so as to enable a purging gas to be able to flow through the fuel processing assembly to remove humidified fuel gas from the processing assembly and to enable a purging gas to be able to flow through the anode of the fuel cell.

  2. Approaches to systems biology. Four methods to study single-cell gene expression, cell motility, antibody reactivity, and respiratory metabolism

    DEFF Research Database (Denmark)

    Hagedorn, Peter

    To understand how complex systems, such as cells, function, comprehensive Measurements of their constituent parts must be made. This can be achieved by combining methods that are each optimized to measure specific parts of the system. Four such methods,each covering a different area, are presented......: Transcript profiling of one cell type extracted from a complex tissue containing several cell types; observation and recording of cell motility; measurement of antibody reactivities using microarrays; and invivo measurement of free and bound NADH in mitochondria. Detailed statistical analysis of the data...... from such measurements allows models of the system to be developed and tested. For each of the methods, such analysis and modelling approaches have beenapplied and are presented: Differentially regulated genes are identified and classified according to function; cell-specfic motility models are...

  3. Use of closed circuit tv systems at the IEM cell

    International Nuclear Information System (INIS)

    The Interim Examination and Maintenance (IEM) Cell is a vertical, argon inerted hot cell located within the containment building of the Fast Flux Test Facility (FFTF). The IEM Cell has two basic functions: (1) to perform disassembly and non-destructive testing on radioactive, sodium-wetted reactor components, and (2) to provide a shielded work volume where radioactive, sodium-wetted reactor and refueling equipment can be repaired and maintained. Another important aspect of the cell is the ability to remotely remove, transfer and reinstall in-cell equipment for maintenance. This paper describes one technique used to enhance in-cell visibility during these remote operations

  4. Use of closed circuit TV systems at the IEM cell

    International Nuclear Information System (INIS)

    The Interim Examination and Maintenance (IEM) Cell is a vertical, argon inerted hot cell located within the containment building of the Fast Flux Test Facility (FFTF). The IEM Cell has two basic functions: (1) to perform disassembly and nondestructive testing on radioactive, sodium-wetted reactor components, and (2) to provide a shielded work volume where radioactive, sodium-wetted reactor and refueling equipment can be repaired and maintained. Another important aspect of the cell is the ability to remotely remove, transfer and reinstall in-cell equipment for maintenance. This paper describes one technique used to enhance in-cell visibility during these remote operations

  5. A Continuous-Exchange Cell-Free Protein Synthesis System Based on Extracts from Cultured Insect Cells

    OpenAIRE

    Marlitt Stech; Quast, Robert B.; Rita Sachse; Corina Schulze; Wüstenhagen, Doreen A.; Stefan Kubick

    2014-01-01

    In this study, we present a novel technique for the synthesis of complex prokaryotic and eukaryotic proteins by using a continuous-exchange cell-free (CECF) protein synthesis system based on extracts from cultured insect cells. Our approach consists of two basic elements: First, protein synthesis is performed in insect cell lysates which harbor endogenous microsomal vesicles, enabling a translocation of de novo synthesized target proteins into the lumen of the insect vesicles or, in the case ...

  6. CellSense: A Probabilistic RSSI-based GSM Positioning System

    OpenAIRE

    Ibrahim, Mohamed; Youssef, Moustafa

    2010-01-01

    Context-aware applications have been gaining huge interest in the last few years. With cell phones becoming ubiquitous computing devices, cell phone localization has become an important research problem. In this paper, we present CellSense, a prob- abilistic RSSI-based fingerprinting location determina- tion system for GSM phones.We discuss the challenges of implementing a probabilistic fingerprinting local- ization technique in GSM networks and present the details of the CellSense system and...

  7. Organic Production Systems: What the Biological Cell Can Teach Us About Manufacturing

    OpenAIRE

    Lieven Demeester; Knut Eichler; Christoph H. Loch

    2004-01-01

    Biological cells run complicated and sophisticated production systems. The study of the cell's production technology provides us with insights that are potentially useful in industrial manufacturing. When comparing cell metabolism with manufacturing techniques in industry, we find some striking commonalities, but also some important differences. Like today's well-run factories, the cell operates a very lean production system, assures quality at the source, and uses component commonality to si...

  8. Dynamic characteristics of an automotive fuel cell system for transitory load changes

    OpenAIRE

    Rabbani, Raja Abid; Rokni, Masoud

    2013-01-01

    A dynamic model of Polymer Electrolyte Membrane Fuel Cell (PEMFC) system is developed to investigate the behavior and transient response of a fuel cell system for automotive applications. Fuel cell dynamics are subjected to reactant flows, heat management and water transportation inside the fuel cell. Therefore, a control-oriented model has been devised in Aspen Plus Dynamics, which accommodates electrochemical, thermal, feed flow and water crossover models in addition to two-phase calculatio...

  9. T Cells That Promote B-Cell Maturation in Systemic Autoimmunity

    OpenAIRE

    Weinstein, Jason S.; Hernandez, Sairy G.; Craft, Joe

    2012-01-01

    Follicular helper T (Tfh) cells play an essential role in helping B cells generate antibodies upon pathogen encounters. Such T-cell help classically occurs in germinal centers (GCs) located in B-cell follicles of secondary lymphoid organs, a site of immunoglobulin affinity maturation and isotype switching. B-cell maturation also occurs extrafollicularly, in the red pulp of the spleen and medullary cords in lymph nodes, with plasma cell formation and antibody production. Development of extrafo...

  10. A review of decellularized stem cell matrix: a novel cell expansion system for cartilage tissue engineering

    OpenAIRE

    M Pei; Li JT; Shoukry, M; Y Zhang

    2011-01-01

    Cell-based therapy is a promising biological approach for the treatment of cartilage defects. Due to the small size of autologous cartilage samples available for cell transplantation in patients, cells need to be expanded to yield a sufficient cell number for cartilage repair. However, chondrocytes and adult stem cells tend to become replicatively senescent once they are expanded on conventional plastic flasks. Many studies demonstrate that the loss of cell properties is concomitant with the ...

  11. Innovative production of bio-cellulose using a cell-free system derived from a single cell line.

    Science.gov (United States)

    Ullah, Muhammad Wajid; Ul-Islam, Mazhar; Khan, Shaukat; Kim, Yeji; Park, Joong Kon

    2015-11-01

    The current study was intended to produce bio-cellulose through a cell-free system developed by disrupting Gluconacetobacter hansenii PJK through bead-beating. Microscopic analysis indicated the complete disruption of cells (2.6 × 10(7) cells/mL) in 20 min that added 95.12 μg/mL protein, 1.63 mM ATP, and 1.11 mM NADH into the medium. A liquid chromatography mass spectrometry/mass spectrometry linear trap quadrupole (LC-MS/MS LTQ) Orbitrap analysis of cell-lysate confirmed the presence of all key enzymes for bio-cellulose synthesis. Under static conditions at 30 °C, microbial and cell-free systems produced 3.78 and 3.72 g/L cellulose, corresponding to 39.62 and 57.68% yield, respectively after 15 days. The improved yield based on consumed glucose indicated the superiority of cell-free system. Based on current findings and literature, we hypothesized a synthetic pathway for bio-cellulose synthesis in the cell-free system. This approach can overcome some limitations of cellulose-producing cells and offers a wider scope for synthesizing cellulose composites with bactericidal elements through in situ synthesizing approaches. PMID:26256351

  12. Culturing of PC12 Cells, Neuronal Cells, Astrocytes Cultures and Brain Slices in an Open Microfluidic System

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya; Rømer Sørensen, Ane;

    culturing PC12 cells, neuronal cells, astrocytes cultures and brain slices. The microfluidic system provides efficient nutrient delivery, waste removal, access to oxygen, fine control over the neurochemical environment and access to modern microscopy. Additionally, the setup consists of an in vitro...

  13. Immunological Barriers to Stem Cell Therapy in the Central Nervous System

    OpenAIRE

    Tullis, Gregory E.; Kathleen Spears; Kirk, Mark D.

    2014-01-01

    The central nervous system is vulnerable to many neurodegenerative disorders such as Alzheimer's disease that result in the extensive loss of neuronal cells. Stem cells have the ability to differentiate into many types of cells, which make them ideal for treating such disorders. Although stem cell therapy has shown some promising results in animal models for many brain disorders it has yet to translate into the clinic. A major hurdle to the translation of stem cell therapy into the clinic is ...

  14. The role of fuel cells and electrolysers in future efficient energy systems

    DEFF Research Database (Denmark)

    Hendriksen, Peter Vang; Mathiesen, Brian Vad; Pedersen, Allan S.;

    2012-01-01

    Fuel cells can increase the efficiency of the energy system and electrolysers can help enable a de-carbonisation of the energy supply. In this chapter we explain the role of fuel cells in future energy systems together with the role of electrolysers in smart energy systems with increasing...

  15. Biological studies using mammalian cell lines and the current status of the microbeam irradiation system, SPICE

    Science.gov (United States)

    Konishi, T.; Ishikawa, T.; Iso, H.; Yasuda, N.; Oikawa, M.; Higuchi, Y.; Kato, T.; Hafer, K.; Kodama, K.; Hamano, T.; Suya, N.; Imaseki, H.

    2009-06-01

    The development of SPICE (single-particle irradiation system to cell), a microbeam irradiation system, has been completed at the National Institute of Radiological Sciences (NIRS). The beam size has been improved to approximately 5 μm in diameter, and the cell targeting system can irradiate up to 400-500 cells per minute. Two cell dishes have been specially designed: one a Si 3N 4 plate (2.5 mm × 2.5 mm area with 1 μm thickness) supported by a 7.5 mm × 7.5 mm frame of 200 μm thickness, and the other a Mylar film stretched by pressing with a metal ring. Both dish types may be placed on a voice coil stage equipped on the cell targeting system, which includes a fluorescent microscope and a CCD camera for capturing cell images. This microscope system captures images of dyed cell nuclei, computes the location coordinates of individual cells, and synchronizes this with the voice coil motor stage and single-particle irradiation system consisting of a scintillation counter and a beam deflector. Irradiation of selected cells with a programmable number of protons is now automatable. We employed the simultaneous detection method for visualizing the position of mammalian cells and proton traversal through CR-39 to determine whether the targeted cells are actually irradiated. An immuno-assay was also performed against γ-H2AX, to confirm the induction of DNA double-strand breaks in the target cells.

  16. Alkaline Exchange Membrane (AEM) for High-Efficiency Fuel Cells, Electrolyzers and Regenerative Fuel Cell Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop an alkaline exchange membrane (AEM)for use as a polymer electrolyte in both fuel cell and electrolyzer systems.  The ultimate goal in AEM development...

  17. A Safeguard System for Induced Pluripotent Stem Cell-Derived Rejuvenated T Cell Therapy

    Directory of Open Access Journals (Sweden)

    Miki Ando

    2015-10-01

    Full Text Available The discovery of induced pluripotent stem cells (iPSCs has created promising new avenues for therapies in regenerative medicine. However, the tumorigenic potential of undifferentiated iPSCs is a major safety concern for clinical translation. To address this issue, we demonstrated the efficacy of suicide gene therapy by introducing inducible caspase-9 (iC9 into iPSCs. Activation of iC9 with a specific chemical inducer of dimerization (CID initiates a caspase cascade that eliminates iPSCs and tumors originated from iPSCs. We introduced this iC9/CID safeguard system into a previously reported iPSC-derived, rejuvenated cytotoxic T lymphocyte (rejCTL therapy model and confirmed that we can generate rejCTLs from iPSCs expressing high levels of iC9 without disturbing antigen-specific killing activity. iC9-expressing rejCTLs exert antitumor effects in vivo. The system efficiently and safely induces apoptosis in these rejCTLs. These results unite to suggest that the iC9/CID safeguard system is a promising tool for future iPSC-mediated approaches to clinical therapy.

  18. Charging system for fuel cell applications; Luftversorgung fuer Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Metz, Dietmar; Werner, Juergen; Muenz, Stefan [BorgWarner Turbo Systems, Kirchheimbolanden (Germany). Bereich Advanced Engineering; Becker, Michael [BorgWarner BERU Systems GmbH, Ludwigsburg (Germany)

    2013-04-15

    Vehicles with fuel cells become increasingly important, as OEM have announced to introduce fuel cell vehicles into the market starting in 2015. Similarly to a combustion engine, the fuel cell also needs compressed air to provide high power density. For a longer period, BorgWarner has collaborated with different OEM and has developed a turbocharger for fuel cells with high maturity level which is scalable to support various applications. (orig.)

  19. Regulation of the adaptive immune system by innate lymphoid cells

    OpenAIRE

    Hepworth, Matthew R.; Sonnenberg, Gregory F.

    2014-01-01

    Innate lymphoid cells (ILCs) are a group of lymphocytes that promote rapid cytokine-dependent innate immunity, inflammation and tissue repair. In addition, a growing body of evidence suggests ILCs can influence adaptive immune cell responses. During fetal development a subset of ILCs orchestrate the generation and maturation of secondary lymphoid tissues. Following birth, ILCs continue to modulate adaptive immune cell responses indirectly through interactions with stromal cells in lymphoid ti...

  20. Stem cell autotomy and niche interaction in different systems

    OpenAIRE

    Dorn, David C.; Dorn, August

    2015-01-01

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form ...

  1. Method and system for purification of gas/liquid streams for fuel cells or electrolysis cells

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention provides in embodiments a method for purification of inlet gas/liquid streams in a fuel cell or electrolysis cell, the fuel cell or electrolysis cell comprising at least a first electrode, an electrolyte and a second electrode, the method comprising the steps of: - providing...... at least one scrubber in the gas/liquid stream at the inlet side of the first electrode of the fuel cell or electrolysis cell; and/or providing at least one scrubber in the gas/liquid stream at the inlet side of the second electrode of the fuel cell or electrolysis cell; and - purifying the gas...... purified with the at least one scrubber, with the proviso that the fuel cell or electrolysis cell is not a solid oxide cell....

  2. High efficiency solar cells combining a perovskite and a silicon heterojunction solar cells via an optical splitting system

    Energy Technology Data Exchange (ETDEWEB)

    Uzu, Hisashi, E-mail: Hisashi.Uzu@kaneka.co.jp, E-mail: npark@skku.edu; Ichikawa, Mitsuru; Hino, Masashi; Nakano, Kunihiro; Meguro, Tomomi; Yamamoto, Kenji [Kaneka Corporation, 5-1-1, Torikai-Nishi, Settsu, Osaka 566-0072 (Japan); Hernández, José Luis [Kaneka Belgium N.V., Nijverheidsstraat 16, 2260 Westerlo-Oevel (Belgium); Kim, Hui-Seon; Park, Nam-Gyu, E-mail: Hisashi.Uzu@kaneka.co.jp, E-mail: npark@skku.edu [School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746 (Korea, Republic of)

    2015-01-05

    We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an “optical splitter.” An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550 nm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells.

  3. High efficiency solar cells combining a perovskite and a silicon heterojunction solar cells via an optical splitting system

    International Nuclear Information System (INIS)

    We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an “optical splitter.” An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH3NH3PbI3 perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550 nm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells

  4. Natural killer (NK) cells inhibit systemic metastasis of glioblastoma cells and have therapeutic effects against glioblastomas in the brain

    OpenAIRE

    Lee, Se Jeong; Kang, Won Young; Yoon, Yeup; Jin, Ju Youn; Song, Hye Jin; Her, Jung Hyun; Kang, Sang Mi; Hwang, Yu Kyeong; Kang, Kyeong Jin; Joo, Kyeung Min; Nam, Do-Hyun

    2015-01-01

    Background Glioblastoma multiforme (GBM) is characterized by extensive local invasion, which is in contrast with extremely rare systemic metastasis of GBM. Molecular mechanisms inhibiting systemic metastasis of GBM would be a novel therapeutic candidate for GBM in the brain. Methods Patient-derived GBM cells were primarily cultured from surgical samples of GBM patients and were inoculated into the brains of immune deficient BALB/c-nude or NOD-SCID IL2Rgammanull (NSG) mice. Human NK cells were...

  5. Design of a trigeneration system using a high temperature fuel cell

    OpenAIRE

    Malico, Isabel; Carvalhinho, Ana Paula; Tenreiro, Joaquim

    2009-01-01

    Fuel cells are one of the technologies available for CHCP, combined heat, cooling and power production, systems. They offer several advantages over more conventional systems, but they still need to overcome a number of barriers until they are readily available for commercialization. At this stage, it is important to fund demonstration projects that experiment with fuel cell technology in pre-commercial situations. In this context, a CHCP system, using a high temperature fuel cell (SOFC) and a...

  6. Increasing Fuel Efficiency of Direct Methanol Fuel Cell Systems with Feedforward Control of the Operating Concentration

    OpenAIRE

    Youngseung Na; Federico Zenith; Ulrike Krewer

    2015-01-01

    Most of the R&D on fuel cells for portable applications concentrates on increasing efficiencies and energy densities to compete with other energy storage devices, especially batteries. To improve the efficiency of direct methanol fuel cell (DMFC) systems, several modifications to system layouts and operating strategies are considered in this paper, rather than modifications to the fuel cell itself. Two modified DMFC systems are presented, one with an additional inline mixer and a further ...

  7. MEMS-based flow cytometry: microfluidics-based cell identification system by fluorescent imaging.

    Science.gov (United States)

    Wu, W K; Liang, C K; Huang, J Z

    2004-01-01

    This study utilizes MEMS technology to realize a novel low-cost microfluidics-based biochip system for flow-type cell handling. Powered by vacuum pump, the microfluidic driving system enables cells to move in order one by one in the biochip by an effect of sheath flow prefocus. Then, cells are guided to a fluorescent inspection region where two detection tasks such as cell image identification and cell counting are conducted. Currently, the glass-based biochip has been manufactured and all the related devices have been well set up in our laboratory. With this proposed prototype system, typical results about cell separation of yeast cell and PC-3 cell are available and their separated images are also presented, respectively. PMID:17270801

  8. Temperature dependent estimator for load cells using an adaptive neuro-fuzzy inference system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K-C [Department of Automation Engineering, National Formosa University, Huwei, Yunlin 63208, Taiwan (China)

    2005-01-01

    Accurate weighting of pieces in various temperature environments for load cells is a key feature in many industrial applications. This paper proposes a method to achieve high-precision {+-}0.56/3000 grams for a load-cell-based weighting system by using ANFIS. ANFIS is used to model the relationship between the reading of load cells and the actual weight of samples considering temperature-varying effect and nonlinearity of the load cells. The model of the load-cell-based weighting system can accurately estimate the weight of test samples from the load cell reading. The proposed ANFIS-based method is convenient for use and can improve the precision of digital load cell measurement systems. Experiments demonstrate the validity and effectiveness of fuzzy neural networks for modeling of load cells and the results show that the proposed ANFIS-based method outperforms some existing methods in terms of modeling and prediction accuracy.

  9. Friction measurement system using load cell for Tribotronic system on Pin-On-Disc (POD) tribometer

    International Nuclear Information System (INIS)

    This paper discusses part of Tribotronic system on Pin-On-Disc (POD) Tribometer focusing on friction measurement using load cell. The analysis conducted using MATLAB software to measure Coefficient of Friction (CoF) of 2 sample types in order to prove the validity of the measurement. The 2 samples are lubricant (Shell Helix Fully synthetic oil) and lubricant (Shell Helix Fully synthetic oil) with additive. It is revealed that the measurement of the lubricant with additive shows better CoF (0.006) than lubricant without additive, CoF of 0.02.

  10. A Regulatory Feedback between Plasmacytoid Dendritic Cells and Regulatory B Cells Is Aberrant in Systemic Lupus Erythematosus.

    Science.gov (United States)

    Menon, Madhvi; Blair, Paul A; Isenberg, David A; Mauri, Claudia

    2016-03-15

    Signals controlling the generation of regulatory B (Breg) cells remain ill-defined. Here we report an "auto"-regulatory feedback mechanism between plasmacytoid dendritic cells (pDCs) and Breg cells. In healthy individuals, pDCs drive the differentiation of CD19(+)CD24(hi)CD38(hi) (immature) B cells into IL-10-producing CD24(+)CD38(hi) Breg cells and plasmablasts, via the release of IFN-α and CD40 engagement. CD24(+)CD38(hi) Breg cells conversely restrained IFN-α production by pDCs via IL-10 release. In systemic lupus erythematosus (SLE), this cross-talk was compromised; pDCs promoted plasmablast differentiation but failed to induce Breg cells. This defect was recapitulated in healthy B cells upon exposure to a high concentration of IFN-α. Defective pDC-mediated expansion of CD24(+)CD38(hi) Breg cell numbers in SLE was associated with altered STAT1 and STAT3 activation. Both altered pDC-CD24(+)CD38(hi) Breg cell interactions and STAT1-STAT3 activation were normalized in SLE patients responding to rituximab. We propose that alteration in pDC-CD24(+)CD38(hi) Breg cell interaction contributes to the pathogenesis of SLE. PMID:26968426

  11. Role of the ubiquitin proteasome system in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Corn Paul G

    2007-11-01

    Full Text Available Abstract Renal cell carcinoma (RCC accounts for approximately 2.6% of all cancers in the United States. While early stage disease is curable by surgery, the median survival of metastatic disease is only 13 months. In the last decade, there has been considerable progress in understanding the genetics of RCC. The VHL tumor suppressor gene is inactivated in the majority of RCC cases. The VHL protein (pVHL acts as an E3 ligase that targets HIF-1, the hypoxia inducible transcription factor, for degradation by the ubiquitin proteasome system (UPS. In RCC cases with mutant pVHL, HIF-1 is stabilized and aberrantly expressed in normoxia, leading to the activation of pro-survival genes such as vascular endothelial growth factor (VEGF. This review will focus on the defect in the UPS that underlies RCC and describe the development of novel therapies that target the UPS. Publication history: Republished from Current BioData's Targeted Proteins database (TPdb; http://www.targetedproteinsdb.com.

  12. Single Vector Calibration System for Multi-Axis Load Cells and Method for Calibrating a Multi-Axis Load Cell

    Science.gov (United States)

    Parker, Peter A. (Inventor)

    2003-01-01

    A single vector calibration system is provided which facilitates the calibration of multi-axis load cells, including wind tunnel force balances. The single vector system provides the capability to calibrate a multi-axis load cell using a single directional load, for example loading solely in the gravitational direction. The system manipulates the load cell in three-dimensional space, while keeping the uni-directional calibration load aligned. The use of a single vector calibration load reduces the set-up time for the multi-axis load combinations needed to generate a complete calibration mathematical model. The system also reduces load application inaccuracies caused by the conventional requirement to generate multiple force vectors. The simplicity of the system reduces calibration time and cost, while simultaneously increasing calibration accuracy.

  13. Study on Fuel Cell Network System Considering Reduction in Fuel Cell Capacity Using Load Leveling and Heat Release Loss

    Science.gov (United States)

    Obara, Shin'ya; Kudo, Kazuhiko

    Reduction in fuel cell capacity linked to a fuel cell network system is considered. When the power demand of the whole network is small, some of the electric power generated by the fuel cell is supplied to a water electrolysis device, and hydrogen and oxygen gases are generated. Both gases are compressed with each compressor and they are stored in cylinders. When the electric demand of the whole network is large, both gases are supplied to the network, and fuel cells are operated by these hydrogen and oxygen gases. Furthermore, an optimization plan is made to minimize the quantity of heat release of the hot water piping that connects each building. Such an energy network is analyzed assuming connection of individual houses, a hospital, a hotel, a convenience store, an office building, and a factory. Consequently, compared with the conventional system, a reduction of 46% of fuel cell capacity is expected.

  14. Tc17 Cells in Immunity and Systemic Autoimmunity.

    Science.gov (United States)

    Liang, Yan; Pan, Hai-Feng; Ye, Dong-Qing

    2015-01-01

    Tc17 cells-a subset of CD8(+)T cells-have recently been identified that are characterized by the production of interleukin (IL)-17. Cytokines IL-6 and transforming growth factor-beta 1 (TGF-β1) and transcription factors signaling transducers and activators of transcription (STAT)3, retinoic acid receptor-related orphan nuclear receptor gamma (RORγt), and interferon regulatory factor (IRF)4 are necessary for differentiation of Tc17 cells, controlling expression of molecules essential for Tc17 cell trafficking and function. Current human researches have determined the significance of CD161 expression as either a marker of Tc17 cells or as an effector and regulator of Tc17 cell function. Noncytotoxic Tc17 cells possess a high plasticity to convert into IFN-γ producing cells, which exhibit strong cytotoxic activity. The importance of in vivo plasticity of Tc17 cells for the induction of autoimmune diseases has been demonstrated and Tc17 cells potentially represent novel therapeutic targets in autoimmune diseases. The involvement of interleukin (IL)-17-producing CD8(+)T cells (Tc17) in various conditions, such as infection, cancer, and autoimmune inflammation, has been documented in both humans and mice; however, Tc17 cells have received only marginal attention. Here, we provide an overview of the cytokines and chemokines that characterize the murine and human Tc17 cells. Moreover, we discuss signaling pathways, molecular interactions, and transcriptional events that contribute to Tc17 differentiation and acquisition of effector functions. Also considered is the basis of Tc17 cell plasticity toward the Tc1 lineage, and we suggest that in vivo plasticity of Tc17 cells may be a key feature of Tc17 cell biology in autoimmune diseases. Furthermore, current human researches have revealed that Tc17 cells are different than that in mice because all of them express CD161 and exclusively originate from CD161 precursors present in umbilical cord blood. Finally, we focus on the

  15. Adipose-Derived Stem Cells for Future Regenerative System Medicine

    Directory of Open Access Journals (Sweden)

    Yani Lina

    2012-08-01

    Full Text Available BACKGROUND: The potential use of stem cell-based therapies for repair and regeneration of various tissues and organs offers a paradigm shift that may provide alternative therapeutic solutions for a number of disease. Despite the advances, the availability of stem cells remaining a challenge for both scientist and clinicians in pursuing regenerative medicine. CONTENT: Subcutaneous human adipose tissue is an abundant and accessible cell source for applications in tissue engineering and regenerative medicine. Routinely, the adipose issue is digested with collagenase or related lytic enzymes to release a heterogeneous population for stromal vascular fraction (SVF cells. The SVF cells can be used directly or can be cultured in plastic ware for selection and expansion of an adherent population known as adipose-derived stromal/stem cells (ASCs. Their potential in the ability to differentiate into adipogenic, osteogenic, chondrogenic and other mesenchymal lineages, as well in their other clinically useful properties, includes stimulation of angiogenesis and suppression of inflammation. SUMMARY: Adipose tissue is now recognized as an accessible, abundant and reliable site for the isolation of adult stem cels suitable for the application of tissue engineering and regenerative medicine applications. The past decade has witnessed an explosion of preclinical data relating to the isolation, characterization, cryopreservation, differentiation, and transplantation of freshly isolated stromal vascular fraction cells and adherent, culture-expanded, adipose-derived stromal/stem cells in vitro and in animal models. KEYWORDS: adipose tissue, adult stem cells, regenerative medicine, mesenchymal stem cells.

  16. Central nervous system mast cells in peripheral inflammatory nociception

    Directory of Open Access Journals (Sweden)

    Ellmeier Wilfried

    2011-06-01

    Full Text Available Abstract Background Functional aspects of mast cell-neuronal interactions remain poorly understood. Mast cell activation and degranulation can result in the release of powerful pro-inflammatory mediators such as histamine and cytokines. Cerebral dural mast cells have been proposed to modulate meningeal nociceptor activity and be involved in migraine pathophysiology. Little is known about the functional role of spinal cord dural mast cells. In this study, we examine their potential involvement in nociception and synaptic plasticity in superficial spinal dorsal horn. Changes of lower spinal cord dura mast cells and their contribution to hyperalgesia are examined in animal models of peripheral neurogenic and non-neurogenic inflammation. Results Spinal application of supernatant from activated cultured mast cells induces significant mechanical hyperalgesia and long-term potentiation (LTP at spinal synapses of C-fibers. Lumbar, thoracic and thalamic preparations are then examined for mast cell number and degranulation status after intraplantar capsaicin and carrageenan. Intradermal capsaicin induces a significant percent increase of lumbar dural mast cells at 3 hours post-administration. Peripheral carrageenan in female rats significantly increases mast cell density in the lumbar dura, but not in thoracic dura or thalamus. Intrathecal administration of the mast cell stabilizer sodium cromoglycate or the spleen tyrosine kinase (Syk inhibitor BAY-613606 reduce the increased percent degranulation and degranulated cell density of lumbar dural mast cells after capsaicin and carrageenan respectively, without affecting hyperalgesia. Conclusion The results suggest that lumbar dural mast cells may be sufficient but are not necessary for capsaicin or carrageenan-induced hyperalgesia.

  17. New insights into the immunopathogenesis of systemic lupus erythematosus: the role of T follicular helper cells

    Institute of Scientific and Technical Information of China (English)

    Ma Huijuan; Wan Suigui; Xia Changqing

    2014-01-01

    Objective To review the development of T follicular helper (TFH) cells and their role in systemic lupus erythematosus (SLE) pathogenesis,the effect of dendritic cells (DCs) on TFH cells in SLE,as well as the potential use of TFH cells as a new therapeutic target in clinical practice.Data sources The data used in this review were retrieved mainly from the PubMed database (1989-2013).The terms used in the literature search were "T follicular helper cells," "systemic lupus erythematosus," and "dendritic cells." Study selection Relevant publications about the TFH cells development,the interaction between the TFH cells and the DCs,and the clinical applications of TFH cells were identified,retrieved,and reviewed.Results TFH cells,a novel distinct CD4+ T cell subset,are specialized in providing help to B cells in the formation of germinal centers (GCs) and long-term protective humoral immune responses.The development of TFH cells from na(i)ve CD4+ T cell is a multistep process.As the pivot of immunoregulation,DCs are indispensable for TFH cells generation.In addition to receptor-ligand interactions between TFH cells and DCs,the cytokines secreted by DCs are also necessary for TFH cell generation.TFH cell dysregulation has been implicated in the development of SLE.More evidence from animal models of SLE and SLE patients suggests that TFH cells are necessary for pathogenic autoantibody production.Therefore,therapeutically targeting TFH cells can be a promising approach to treat antibody-mediated autoimmune diseases including SLE.Conclusion TFH cells play a critical role in the pathogenesis of SLE,making them attractive therapeutic targets in clinical practice.

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

    Science.gov (United States)

    Nguyen, Gia Luong Huu

    Fuel cells can produce electricity with high efficiency, low pollutants, and low noise. With the advent of fuel cell technologies, fuel cell systems have since been demonstrated as reliable power generators with power outputs from a few watts to a few megawatts. With proper equipment, fuel cell systems can produce heating and cooling, thus increased its overall efficiency. To increase the acceptance from electrical utilities and building owners, fuel cell systems must operate more dynamically and integrate well with renewable energy resources. This research studies the dynamic performance of fuel cells and the integration of fuel cells with other equipment in three levels: (i) the fuel cell stack operating on hydrogen and reformate gases, (ii) the fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit, and (iii) the hybrid energy system consisting of photovoltaic panels, fuel cell system, and energy storage. In the first part, this research studied the steady-state and dynamic performance of a high temperature PEM fuel cell stack. Collaborators at Aalborg University (Aalborg, Denmark) conducted experiments on a high temperature PEM fuel cell short stack at steady-state and transients. Along with the experimental activities, this research developed a first-principles dynamic model of a fuel cell stack. The dynamic model developed in this research was compared to the experimental results when operating on different reformate concentrations. Finally, the dynamic performance of the fuel cell stack for a rapid increase and rapid decrease in power was evaluated. The dynamic model well predicted the performance of the well-performing cells in the experimental fuel cell stack. The second part of the research studied the dynamic response of a high temperature PEM fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit with high thermal integration. After verifying the model performance with the

  19. Unique cell culture systems for ground based research

    Science.gov (United States)

    Lewis, Marian L.

    1990-01-01

    The horizontally rotating fluid-filled, membrane oxygenated bioreactors developed at NASA Johnson for spacecraft applications provide a powerful tool for ground-based research. Three-dimensional aggregates formed by cells cultured on microcarrier beads are useful for study of cell-cell interactions and tissue development. By comparing electron micrographs of plant seedlings germinated during Shuttle flight 61-C and in an earth-based rotating bioreactor it is shown that some effects of microgravity are mimicked. Bioreactors used in the UAH Bioreactor Laboratory will make it possible to determine some of the effects of altered gravity at the cellular level. Bioreactors can be valuable for performing critical, preliminary-to-spaceflight experiments as well as medical investigations such as in vitro tumor cell growth and chemotherapeutic drug response; the enrichment of stem cells from bone marrow; and the effect of altered gravity on bone and muscle cell growth and function and immune response depression.

  20. Relationships between systemic vascular resistance, blood rheology and nitric oxide in children with sickle cell anemia or sickle cell-hemoglobin C disease. : Hemodynamics in sickle cell disease

    OpenAIRE

    Lamarre, Yann; Hardy-Dessources, Marie-Dominique; Romana, Marc; Lalanne-Mistrih, Marie-Laure; Waltz, Xavier; Petras, Marie; Doumdo, Lydia; Blanchet-Deverly, Anne; Martino, Jean; Tressières, Benoît; Maillard, Frederic; Tarer, Vanessa; Etienne-Julan, Maryse; Connes, Philippe

    2013-01-01

    Vascular function has been found to be impaired in patients with sickle cell disease (SCD). The present study investigated the determinants of systemic vascular resistance in two main SCD syndromes in children: sickle cell anemia (SCA) and sickle cell-hemoglobin C disease (SCC). Nitric oxide metabolites (NOx), hematological, hemorheological, and hemodynamical parameters were investigated in 61 children with SCA and 49 children with SCC. While mean arterial pressure was not different between S...

  1. Ultrasonic Handling of Living Cells in Microfluidic Systems

    OpenAIRE

    Svennebring, Jessica

    2009-01-01

    Microfluidic chips have become a powerful tool in research where biological cells are processed and/or analyzed. One method for contactless cell manipulation in microfluidic chips that has gained an increasing amount of attention the last decade is ultrasonic standing wave (USW) technology. This Thesis explores the biocompatibility of USW technology applied to microfluidic chips, and presents a novel USW-based method for serial processing and accurate characterization of living cells. The bio...

  2. A hybrid solar/diesel water heating system: in medicine area in a hospital in Mexico city; Sistema hibrido de energia solar y diesel para calentamiento de agua: caso en el area de medicina fisica en un hospital en la ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Nolasco Mejia, Miguel; Wolpert Kuri, Jorge [UNAM, Mexico, D.F. (Mexico)

    2000-07-01

    A hybrid solar/diesel water heating system for therapy in a hospital in Mexico is described in this paper. The use of solar energy in hospitals and clinics, represent an environmentally friendly alternative to the burning of fossil fuels. Analysis is made regarding the feasibility of integrating both solar energy and conventional energy (fuel oil) as back up, to satisfy the hot water demand for hydrotherapy in a hospital. Results from simulation show that solar energy is a cheap means to provide up to 60% of the hot water demand. The solar assisted system proposed uses flat plate solar collectors integrated with an existing hot water tank, where water is heated with vapor from a diesel ran boiler. This represents significant savings on the solar system cost. [Spanish] La utilizacion de la energia solar en hospitales y clinicas, representa una posibilidad para obtener ahorros importantes de energia para satisfacer la demanda de agua caliente. En el presente estudio se analiza la demanda de agua caliente para uso en medicina fisica (hidroterapia), en un hospital ubicado en la Cd. De Mexico y la factibilidad de usar la energia solar, empleando como apoyo el sistema tradicional de combustible fosil (diesel). Mediante un analisis termico se determina el calor necesario para satisfacer la demanda de agua caliente. El analisis economico muestra los costos del sistema solar, los ahorros que se tendran y el periodo de recuperacion de la inversion. Los resultados muestran que la utilizacion de la energia solar es factible debido a la disminucion tanto del consumo de combustible, como de las emisiones atmosfericas. Se propone la instalacion de un sistema solar con colectores planos y el aprovechamiento de uno de los dos tanques de agua caliente existentes, donde se efectua la trasferencia de calor al agua por medio de vapor, lo cual disminuye el costo del sistema solar. La aportacion solar puede ser mayor del 60%, el complemento sera aportado por el sistema tradicional con

  3. Identification, localization and morphology of APUD cells in gastroenteropancreatic system of stomach-containing teleosts

    OpenAIRE

    Pan, Qian Sheng; Fang, Zhi Ping; Huang, Feng Jie

    2000-01-01

    AIM: To identify the type localization and morphology of APUD endocrine cells in the gastroenteropancreatic (GEP) system of stomach-containing teleosts, and study APUD endocrine system in the stomach, intestine and pancreas of fish species.

  4. Nanog reporter system in mouse embryonic stem cells based on highly efficient BAC homologous recombination

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nanog is a novel transcription factor specifically expressed in mouse embryonic stem cells (mES cells). It has been reported that Nanog plays an essential role in maintaining multi-potency of ES cells. The expression of Nanog is very sensitive to ES cells differentiation, making Nanog one of the best markers to indicate the status of ES cells. In this study, we developed an efficient method to construct Nanog promoter driven EGFP reporter system based on the BAC homologous recombination. We further generated a Nanog-EGFP reporter mES cell line. This reporter mES cell line exhibited features similar to those of normal mES cells, and the EGFP reporter efficiently reflected the expression of Nanog, indicating the differentiation status of mES cells. We achieved a reliable experimental reporter system to research self-renewal and differentiation of mES cells. The system could facilitate research on culture system of mES cells and researches on the expression and regulation of Nanog and other related factors in mES cells.

  5. System X supercomputer provides super tool for simulation of cell division

    OpenAIRE

    Trulove, Susan

    2007-01-01

    Virginia Tech researchers in computer science and biology have used the university's supercomputer, System X, to create models and algorithms that make it possible to simulate the cell cycle -- the processes leading to cell division. They have demonstrated that the new mathematical models and numerical algorithms provide powerful tools for studying the complex processes going on inside living cells.

  6. 21 CFR 866.6020 - Immunomagnetic circulating cancer cell selection and enumeration system.

    Science.gov (United States)

    2010-04-01

    ... cancer cells in a prepared sample of whole blood. This device is intended for adjunctive use in... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunomagnetic circulating cancer cell selection... Associated Antigen immunological Test Systems § 866.6020 Immunomagnetic circulating cancer cell selection...

  7. Advanced Materials for PEM-Based Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    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

  8. Advanced Materials for PEM-Based Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    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

  9. Self-regulating control of parasitic loads in a fuel cell power system

    Science.gov (United States)

    Vasquez, Arturo (Inventor)

    2011-01-01

    A fuel cell power system comprises an internal or self-regulating control of a system or device requiring a parasitic load. The internal or self-regulating control utilizes certain components and an interconnection scheme to produce a desirable, variable voltage potential (i.e., power) to a system or device requiring parasitic load in response to varying operating conditions or requirements of an external load that is connected to a primary fuel cell stack of the system. Other embodiments comprise a method of designing such a self-regulated control scheme and a method of operating such a fuel cell power system.

  10. Local Microenvironment Controls the Compartmentalization of NK Cell Responses during Systemic Inflammation in Mice.

    Science.gov (United States)

    Rasid, Orhan; Ciulean, Ioana Sonya; Fitting, Catherine; Doyen, Noelle; Cavaillon, Jean-Marc

    2016-09-15

    Systemic inflammatory response syndrome is a whole-body reaction to a triggering insult that often results in life-threatening illness. Contributing to the development of this inflammatory cascade are numerous cellular partners, among which NK cells were shown to play a key role. Accumulating evidence points to organ-specific properties of systemic inflammation and NK cells. However, little is known about compartment-specific activation of NK cells during systemic inflammatory response syndrome or the relative contribution of NK cell-intrinsic properties and microenvironmental cues. In this study, we undertook a sequential characterization of NK responses in the spleen, lungs, bone marrow, peritoneum, and blood using a mouse model of endotoxemia. We report that, despite similar systemic dynamics of NK cell responses, expression of activation markers (CD69 and CD25) and effector molecules (IFN-γ, granzyme B, and IL-10) display organ-specific thresholds of maximum activation. Using adoptive transfers of spleen and lung NK cells, we found that these cells have the capacity to quickly adapt to a new environment and adjust their response levels to that of resident NK cells. This functional adaptation occurs without significant alterations in phenotype and independently of subpopulation-specific trafficking. Thus, using a dynamic in vivo-transfer system, to our knowledge our study is the first to report the compartmentalization of NK cells responses during systemic inflammation and to show that NK cell-intrinsic properties and microenvironmental cues are involved in this process, in a sequential manner. PMID:27521338

  11. [Current cell therapy strategies for repairing the central nervous system].

    Science.gov (United States)

    Féron, F

    2007-09-01

    One of the chief contemporary goals of neurologists and neuroscientists is to find a way to overcome the debilitating effects of brain diseases, especially neurodegenerative diseases. Since very few molecules have been found to be efficient in curing the patients and even halting the progression of the symptoms, cell therapy is now seen as an attractive alternative. Two therapeutic strategies are currently under investigation: i) the "substitution" strategy, based on grafts of cells capable of differentiating in the appropriate cells and restoring lost functions and ii) the "neuroprotective" or "conservative" strategy aiming to increase the resistance of spared cells to the toxicity of their environment and to reinforce the body's own mechanisms of healing. Twenty years ago, foetal neuroblasts were the first cells to be transplanted in the brains of patients with Parkinson's or Huntington disease. A phase II clinical trial is presently conducted in France for the latter disorder. However, the numerous ethical and technical issues raised by the use of embryonic and foetal cells have directed the focus of clinicians and researchers towards substitute cell types. In this review, we summarise the main findings of the most recent basic studies and clinical trials based on: i) the grafting of surrogate adult cells such as bone marrow mesenchymal stem cells and olfactory ensheathing cells; ii) the potential therapeutic applications of neuropoiesis - the persistent neurogenesis in the brain - as a source for tissue engraftment and as self-repair by a person's own indigenous population of pluripotent cells and iii) immune-based therapy (autologous activated macrophages and T cell vaccination) as well as administration of immunomodulatory molecules. Unexpectedly, it has been found that undifferentiated adult stem cells can display immune-like functions when they home in on an inflamed brain area while immune cells and immunosuppressors can improve functional and

  12. Efficient dielectrophoretic cell enrichment using a dielectrophoresis-well based system

    OpenAIRE

    Abdul Razak, Mohd Azhar; Hoettges, Kai F.; Fatoyinbo, Henry O.; Labeed, Fatima H.; Hughes, Michael P

    2013-01-01

    Whilst laboratory-on-chip cell separation systems using dielectrophoresis are increasingly reported in the literature, many systems are afflicted by factors which impede “real world” performance, chief among these being cell loss (in dead spaces, attached to glass and tubing surfaces, or sedimentation from flow), and designs with large channel height-to-width ratios (large channel widths, small channel heights) that make the systems difficult to interface with other microfluidic systems. In t...

  13. Carbonate fuel cell system with integrated carbon dioxide/thermal management

    Energy Technology Data Exchange (ETDEWEB)

    Paetsch, L.

    1995-08-01

    The objective of the present work is to define the stack design and system requirements for a commercial-scale carbonate fuel cell with an integrated carbon dioxide management system. Significant simplification and cost reduction of the system is achieved by direct transfer of the fuel exhaust to the oxidant inlet of the fuel cell, thereby eliminating the anode exhaust converter and high temperature piping utilized in conventional system designs.

  14. Model systems to study biochemical functions of rat sertoli cells

    NARCIS (Netherlands)

    J.M.W. Toebosch (Annemarie)

    1990-01-01

    textabstractDevelopment of roale genn cells (spermatogenesis) takes place in the testicular seminiferous tubules. The honrones follicle-stimulating honnone (FSH) and testosterone are essential for the initiation and maintenance of spermatogenesis. n>e genn cells in the tubules (spermatogonia, sperma

  15. Pancreatic differentiation from pluripotent stem cells: Tweaking the system

    Institute of Scientific and Technical Information of China (English)

    Andrew M Holland; Andrew G Elefanty; Edouard G Stanley

    2009-01-01

    @@ Autoimmune destruction of insulin producing pancreatic β cells results in type 1 diabetes, a condition for which there is presently no cure. Clinical trials indicate that, in some instances, control of blood glucose can be restored by transplantation of cadaveric derived islets [1], raising hopes that such cell-based therapies may eventually form part of a curative treatment.

  16. Immune cells: more than simple carriers for systemic delivery of oncolytic viruses

    Directory of Open Access Journals (Sweden)

    Eisenstein S

    2014-11-01

    Full Text Available Samuel Eisenstein,1 Shu-Hsia Chen,2 Ping-Ying Pan21Department of Surgery, 2Department of Oncological Sciences and Tisch Cancer Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, USAAbstract: Oncolytic virotherapy on its own has numerous drawbacks, including an inability of the virus to actively target tumor cells and systemic toxicities at the high doses necessary to effectively treat tumors. Addition of immune cell-based carriers of oncolytic viruses holds promise as a technique in which oncolytic virus can be delivered directly to tumors in smaller and less toxic doses. Interestingly, the cell carriers themselves have also demonstrated antitumor effects, which can be augmented further by tailoring the appropriate oncolytic virus to the appropriate cell type. This review discusses the multiple factors that go into devising an effective, cell-based delivery system for oncolytic viruses.Keywords: oncolytic virus, cell carrier, immune cells, cancer therapy, myeloid-derived suppressor cells

  17. Systemic Therapy for Metastatic Non-Clear Cell Renal Cell Carcinoma: Recent Progress and Future Directions

    OpenAIRE

    Chowdhury, Simon; Matrana, Marc; Tsang, Christopher; Atkinson, Bradley; Choueiri, Toni K.; Tannir, Nizar M.

    2011-01-01

    Renal cell carcinoma (RCC) encompasses a heterogeneous group of histological subtypes of which clear-cell RCC (CCRCC) is the most common comprising more than 70–80% of all cases. Papillary renal cell carcinoma (PRCC) is the next most common comprising 10–15% of cases. PRCC is refractory to chemotherapy, immunotherapy and hormonal therapy.

  18. Round Trip Energy Efficiency of NASA Glenn Regenerative Fuel Cell System

    Science.gov (United States)

    Garcia, Christopher P.; Chang, Bei-jiann; Johnson, Donald W.; Bents, David J.; Scullin, Vincent J.; Jakupca, Ian J.; Scullin, Vincent J.; Jakupca, Ian J.

    2006-01-01

    NASA Glenn Research Center (GRC) has recently demonstrated a Polymer Electrolyte Membrane (PEM) based hydrogen/oxygen regenerative fuel cell system (RFCS) that operated for a charge/discharge cycle with round trip efficiency (RTE) greater than 50 percent. The regenerative fuel cell system (RFCS) demonstrated closed loop energy storage over a pressure range of 90 to 190 psig. In charge mode, a constant electrical power profile of 7.1 kWe was absorbed by the RFCS and stored as pressurized hydrogen and oxygen gas. In discharge mode, the system delivered 3 to 4 kWe of electrical power along with product water. Fuel cell and electrolyzer power profiles and polarization performance are documented in this paper. Individual cell performance and the variation of cell voltages within the electrochemical stacks are also reported. Fuel cell efficiency, electrolyzer efficiency, and the system RTE were calculated from the test data and are included below.

  19. High Concentrating GaAs Cell Operation Using Optical Waveguide Solar Energy System

    Science.gov (United States)

    Nakamura, T.; Case, J. A.; Timmons, M. L.

    2004-01-01

    This paper discusses the result of the concentrating photovoltaic (CPV) cell experiments conducted with the Optical Waveguide (OW) Solar Energy System. The high concentration GaAs cells developed by Research Triangle Institute (RTI) were combined with the OW system in a "fiber-on-cell" configuration. The sell performance was tested up to the solar concentration of 327. Detailed V-I characteristics, power density and efficiency data were collected. It was shown that the CPV cells combined with the OW solar energy system will be an effective electric power generation device.

  20. Modeling and control of a small solar fuel cell hybrid energy system

    Institute of Scientific and Technical Information of China (English)

    LI Wei; ZHU Xin-jian; CAO Guang-yi

    2007-01-01

    This paper describes a solar photovoltaic fuel cell (PVEC) hybrid generation system consisting of a photovoltaic (PV) generator, a proton exchange membrane fuel cell (PEMFC), an electrolyser, a supercapacitor, a storage gas tank and power conditioning unit (PCU). The load is supplied from the PV generator with a fuel cell working in parallel. Excess PV energy when available is converted to hydrogen using an electrolyser for later use in the fuel cell. The individual mathematical model for each component is presented. Control strategy for the system is described. MATLAB/Simulink is used for the simulation of this highly nonlinear hybrid energy system. The simulation results are shown in the paper.

  1. An in-cell alpha detection system for radioisotope component assembly operations

    International Nuclear Information System (INIS)

    A remotely operated alpha detection system is being developed for use at the Radioisotope Power Systems Facility at the US Department of Energy's Hanford Site. It will be used in hot cells being constructed to assemble components of Radioisotope Thermoelectric Generators for space power applications. The in-cell detection equipment will survey radiological swipe samples to determine smearable surface contamination levels on radioisotope fuel, fueled components, and hot-cell work areas. This system is potentially adaptable to other hot cell and glovebox applications where radiation dose rates and contamination levels are expected to be low. 2 figs

  2. Regulation of intestinal immune system by dendritic cells.

    Science.gov (United States)

    Ko, Hyun-Jeong; Chang, Sun-Young

    2015-02-01

    Innate immune cells survey antigenic materials beneath our body surfaces and provide a front-line response to internal and external danger signals. Dendritic cells (DCs), a subset of innate immune cells, are critical sentinels that perform multiple roles in immune responses, from acting as principal modulators to priming an adaptive immune response through antigen-specific signaling. In the gut, DCs meet exogenous, non-harmful food antigens as well as vast commensal microbes under steady-state conditions. In other instances, they must combat pathogenic microbes to prevent infections. In this review, we focus on the function of intestinal DCs in maintaining intestinal immune homeostasis. Specifically, we describe how intestinal DCs affect IgA production from B cells and influence the generation of unique subsets of T cell. PMID:25713503

  3. Successive evaluation of multiple parameters in individual cells: the SEMPIC photometric system.

    Science.gov (United States)

    Dörmer, P; Pachmann, K; Lau, B

    1978-12-28

    An automated microphotometric system has been designed for the successive assessment of a maximum number of parameters from individual cells. The hardware and software elements are described as well as the various photometric functions that can be performed. The aim is to obtain a multiparameter analysis of morphology, cytochemistry, cell surface characteristics, and metabolic activity including cell cycle characteristics for any set of cells selected from a sample. The combination of DNA synthesis rate determination in a really quantitative approach with the analysis of features of nuclear chromatin texture opens up a new field for associating morphology with functional properties. Examples of application are presented to demonstrate the applicability of the system in a heterogeneous cell population of a very limited sample size. For this purpose, human peripheral blood cells grown in diffusion chambers in preirradiated mice were investigated. It is shown that, depending on their functions, different cell types may have quite different nuclear-to-cell area ratios. Further, a crude morphological parameter, such as the degree of basophilia of Giemsa-stained cells, may be associated with the rate of DNA synthesis, thus bearing information on the replicative activity of a cell. Cell surface properties related to the leukemia-associated cALL antigen are investigated in a human-derived cell line and correlated with cell-cycle characteristics. It is concluded that different antigenic sites rather than cell-cycle dependent differences of antigen density account for the outcome of a bimodal distribution. PMID:283066

  4. Single-cell-based sensors and synchrotron FTIR spectroscopy: a hybrid system towards bacterial detection.

    Science.gov (United States)

    Veiseh, Mandana; Veiseh, Omid; Martin, Michael C; Bertozzi, Carolyn; Zhang, Miqin

    2007-09-30

    Microarrays of single macrophage cell-based sensors were developed and demonstrated for potential real-time bacterium detection by synchrotron FTIR microscopy. The cells were patterned on gold electrodes of silicon oxide substrates by a surface engineering technique, in which the gold electrodes were immobilized with fibronectin to mediate cell adhesion and the silicon oxide background was passivated with polyethylene glycol (PEG) to resist protein adsorption and cell adhesion. Cell morphology and IR spectra of single, double, and triple cells on gold electrodes exposed to lipopolysaccharide (LPS) of different concentrations were compared to reveal the detection capability of this cell-based sensing platform. The single-cell-based system was found to generate the most significant and consistent IR spectrum shifts upon exposure to LPS, thus providing the highest detection sensitivity. Changes in cell morphology and IR shifts upon cell exposure to LPS were found to be dependent on the LPS concentration and exposure time, which established a method for the identification of LPS concentration and infected cell population. Possibility of using this single-cell system with conventional IR spectroscopy as well as its limitation was investigated by comparing IR spectra of single-cell arrays with gold electrode surface areas of 25, 100, and 400 microm2 using both synchrotron and conventional FTIR spectromicroscopes. This cell-based platform may potentially provide real-time, label-free, and rapid bacterial detection, and allow for high-throughput statistical analyses, and portability. PMID:17560777

  5. Selectins mediate small cell lung cancer systemic metastasis.

    Directory of Open Access Journals (Sweden)

    Franziska Heidemann

    Full Text Available Metastasis formation is the major reason for the extremely poor prognosis in small cell lung cancer (SCLC patients. The molecular interaction partners regulating metastasis formation in SCLC are largely unidentified, however, from other tumor entities it is known that tumor cells use the adhesion molecules of the leukocyte adhesion cascade to attach to the endothelium at the site of the future metastasis. Using the human OH-1 SCLC line as a model, we found that these cells expressed E- and P-selectin binding sites, which could be in part attributed to the selectin binding carbohydrate motif sialyl Lewis A. In addition, protein backbones known to carry these glycotopes in other cell lines including PSGL-1, CD44 and CEA could be detected in in vitro and in vivo grown OH1 SCLC cells. By intravital microscopy of murine mesenterial vasculature we could capture SCLC cells while rolling along vessel walls demonstrating that SCLC cells mimic leukocyte rolling behavior in terms of selectin and selectin ligand interaction in vivo indicating that this mechanism might indeed be important for SCLC cells to seed distant metastases. Accordingly, formation of spontaneous distant metastases was reduced by 50% when OH-1 cells were xenografted into E-/P-selectin-deficient mice compared with wild type mice (p = 0.0181. However, as metastasis formation was not completely abrogated in selectin deficient mice, we concluded that this adhesion cascade is redundant and that other molecules of this cascade mediate metastasis formation as well. Using several of these adhesion molecules as interaction partners presumably make SCLC cells so highly metastatic.

  6. A novel three-dimensional system to study interactions between endothelial cells and neural cells of the developing central nervous system

    Directory of Open Access Journals (Sweden)

    Milner Richard

    2007-01-01

    Full Text Available Abstract Background During angiogenesis in the developing central nervous system (CNS, endothelial cells (EC detach from blood vessels growing on the brain surface, and migrate into the expanding brain parenchyma. Brain angiogenesis is regulated by growth factors and extracellular matrix (ECM proteins secreted by cells of the developing CNS. In addition, recent evidence suggests that EC play an important role in establishing the neural stem cell (NSC niche. Therefore, two-way communication between EC and neural cells is of fundamental importance in the developing CNS. To study the interactions between brain EC and neural cells of the developing CNS, a novel three-dimensional (3-D murine co-culture system was developed. Fluorescent-labelled brain EC were seeded onto neurospheres; floating cellular aggregates that contain NSC/neural precursor cells (NPC and smaller numbers of differentiated cells. Using this system, brain EC attachment, survival and migration into neurospheres was evaluated and the role of integrins in mediating the early adhesive events addressed. Results Brain EC attached, survived and migrated deep into neurospheres over a 5-day period. Neurospheres express the ECM proteins fibronectin and laminin, and brain EC adhesion to neurospheres was inhibited by RGD peptides and antibodies specific for the β1, but not the α6 integrin subunit. Conclusion A novel 3-D co-culture system for analysing the interactions between EC and neural cells of the developing CNS is presented. This system could be used to investigate the reciprocal influence of EC and NSC/NPC; to examine how NSC/NPC influence cerebral angiogenesis, and conversely, to examine how EC regulate the maintenance and differentiation of NSC/NPC. Using this system it is demonstrated that EC attachment to neurospheres is mediated by the fibronectin receptor, α5β1 integrin.

  7. Cell saver for on-pump coronary operations reduces systemic inflammatory markers: a randomized trial

    DEFF Research Database (Denmark)

    Damgaard, Sune; Nielsen, Claus Henrik; Andersen, Lars Willy;

    2010-01-01

    This study investigated whether intraoperative use of a cell saver reduces the systemic inflammatory response after coronary operations using cardiopulmonary bypass (CPB).......This study investigated whether intraoperative use of a cell saver reduces the systemic inflammatory response after coronary operations using cardiopulmonary bypass (CPB)....

  8. Development of 3-D Hydrogel Culture Systems With On-Demand Cell Separation

    OpenAIRE

    Hamilton, Sharon K.; Bloodworth, Nathaniel C.; Massad, Christopher S.; Hammoudi, Taymour M.; Suri, Shalu; Yang, Peter J.; Lu, Hang; Temenoff, Johnna S.

    2013-01-01

    Recently there has been an increased interest in the effects of paracrine signaling between groups of cells, particularly in the context of better understanding how stem cells contribute to tissue repair. Most current 3-D co-culture methods lack the ability to effectively separate 2 cell populations after the culture period, which is important for simultaneously analyzing the reciprocal effects of each cell type on the other. Here, we detail the development of a 3-D hydrogel co-culture system...

  9. CellSense: An Accurate Energy-Efficient GSM Positioning System

    OpenAIRE

    Ibrahim, Mohamed; Youssef, Moustafa

    2011-01-01

    Context-aware applications have been gaining huge interest in the last few years. With cell phones becoming ubiquitous computing devices, cell phone localization has become an important research problem. In this paper, we present CellSense, a prob- abilistic RSSI-based fingerprinting location determi- nation system for GSM phones. We discuss the chal- lenges of implementing a probabilistic fingerprinting localization technique in GSM networks and present the details of the CellSense systemand...

  10. Optimum design of bipolar plates for separate air flow cooling system of PEM fuel cells stacks

    Science.gov (United States)

    Franco, Alessandro

    2015-12-01

    The paper discusses about thermal management of PEM fuel cells. The objective is to define criteria and guidelines for the design of the air flow cooling system of fuel cells stacks for different combination of power density, bipolar plates material, air flow rate, operating temperature It is shown that the optimization of the geometry of the channel permits interesting margins for maintaining the use of separate air flow cooling systems for high power density PEM fuel cells.

  11. Development of a 3D coculture system to study adipocyte and lymph node cell interactions

    OpenAIRE

    Daya, S.; Loughlin, J.; MacQueen, H.

    2006-01-01

    We have developed a long term 3-dimensional coculture system with adipocytes and lymph node cells for the purpose of investigating interactions between these cells in vitro. Present experimental work with the culture system is aimed at introducing lymph node cells, in proportions similar to those found in intact lymph nodes, among differentiated adipocytes and observing interactions and the establishment of a spatial relationship between them. Co-cultures will be used to investigate the ly...

  12. NASA Glenn Research Center's Fuel Cell Stack, Ancillary and System Test and Development Laboratory

    Science.gov (United States)

    Loyselle, Patricia L.; Prokopius, Kevin P.; Becks, Larry A.; Burger, Thomas H.; Dick, Joseph F.; Rodriguez, George; Bremenour, Frank; Long, Zedock

    2011-01-01

    At the NASA Glenn Research Center, a fully operational fuel cell test and evaluation laboratory is available which is capable of evaluating fuel cell components and systems for future NASA missions. Components and subsystems of various types can be operated and monitored under a variety of conditions utilizing different reactants. This fuel cell facility can test the effectiveness of various component and system designs to meet NASA's needs.

  13. Object-oriented architecture of control system for agile manufacturing cells

    OpenAIRE

    Lau, HCW; Ning, A.; Chan, FTS; Zhang, J.

    2000-01-01

    The depiction of the agile manufacturing cell includes a synopsis of some of the change proficiencies obtained by the configuration. To achieve agile configuration, the cell control system for agile manufacturing must be rapidly and efficiently generated or modified. In this paper, the object-oriented architecture is defined that supports design and implementation of highly reconfigurable control systems for agile manufacturing cells, which is composed of database objects, control objects, an...

  14. The cell monolayer trajectory from the system state point of view.

    Science.gov (United States)

    Stys, Dalibor; Vanek, Jan; Nahlik, Tomas; Urban, Jan; Cisar, Petr

    2011-10-01

    Time-lapse microscopic movies are being increasingly utilized for understanding the derivation of cell states and predicting cell future. Often, fluorescence and other types of labeling are not available or desirable, and cell state-definitions based on observable structures must be used. We present the methodology for cell behavior recognition and prediction based on the short term cell recurrent behavior analysis. This approach has theoretical justification in non-linear dynamics theory. The methodology is based on the general stochastic systems theory which allows us to define the cell states, trajectory and the system itself. We introduce the usage of a novel image content descriptor based on information contribution (gain) by each image point for the cell state characterization as the first step. The linkage between the method and the general system theory is presented as a general frame for cell behavior interpretation. We also discuss extended cell description, system theory and methodology for future development. This methodology may be used for many practical purposes, ranging from advanced, medically relevant, precise cell culture diagnostics to very utilitarian cell recognition in a noisy or uneven image background. In addition, the results are theoretically justified. PMID:21879106

  15. Asymmetric cell division of stem cells in the lung and other systems

    Directory of Open Access Journals (Sweden)

    AhmedH. K.El-Hashash

    2014-07-01

    Full Text Available New insights have been added to identification, behavior and cellular properties of embryonic and tissue-specific stem cells over the last few years. The modes of stem cell division, asymmetric versus symmetric, are tightly regulated during development and regeneration. The proper choice of a stem cell to divide asymmetrically or symmetrically has great consequences for development and disease because inappropriate asymmetric division disrupts organ morphogenesis, whereas uncontrolled symmetric division induces tumorigenesis. Therefore, understanding the behavior of lung stem cells could identify innovative solutions for restoring normal morphogenesis and/or regeneration of different organs. In this concise review, we describe recent studies in our laboratory about the mode of division of lung epithelial stem cells. We also compare asymmetric cell division in the lung stem cells with other tissues in different organisms.

  16. Development of a model for thermoeconomic design and operation optimization of a PEM fuel cell system

    International Nuclear Information System (INIS)

    A thorough analysis of a polymer electrolyte membrane (PEM) fuel cell system is presented. A generalized performance model of a single PEM fuel cell is developed and applied in a semi-empirical form for a Ballard Mark V 35-cell, 5 kW PEM fuel cell. A thermodynamic and economic analysis of the components and of the whole system is performed. The purpose of this study is to explore the intrinsic relations among various fuel cell system performance and cost indicators in order to provide insights for new cost effective and high performance designs. Optimization techniques have been applied in order to determine the optimal design and operation mode of the system. An application of the system onboard merchant ships has been considered as an example

  17. Sleeping Beauty system to redirect T-cell specificity for human applications

    Science.gov (United States)

    Maiti, Sourindra; Huls, Helen; Singh, Harjeet; Dawson, Margaret; Figliola, Matthew; Olivares, Simon; Rao, Pullavathi; Jue, Yi; Multani, Asha; Yang, Ge; Zhang, Ling; Kellar, Denise; Ang, Sonny; Torikai, Hiroki; Rabinovich, Brian; Lee, Dean A.; Kebriaei, Partow; Hackett, Perry; Champlin, Richard E.; Cooper, Laurence J.N.

    2013-01-01

    The Sleeping Beauty (SB) transposon/transposase DNA plasmid system is used to genetically modify cells for long-term transgene expression. We adapted the SB system for human application and generated T cells expressing a chimeric antigen receptor (CAR) specific for CD19. Electro-transfer of CD19-specific SB DNA plasmids in PBMC and propagation on CD19+ artificial antigen presenting cells (aAPC) was used to numerically expand CD3+ T cells expressing CAR. By Day 28 of co-culture >90% of expanded CD3+ T cells expressed CAR. CAR+ T cells specifically killed CD19+ target cells and consisted of subsets expressing biomarkers consistent with central memory, ieffector memory, and effector phenotypes. CAR+ T cells contracted numerically in the absence of CD19 antigen, did not express SB11 transposase, and maintained a polyclonal TCRVα and TCRVβ repertoire. Quantitative fluorescence in situ hybridization (Q-FISH) revealed that CAR+ T cells preserved telomere length. Quantitative PCR (Q-PCR) and FISH showed CAR transposon integrated on average once per T-cell genome. CAR+ T cells in peripheral blood can be detected by Q-PCR at a sensitivity of 0.01%. These findings lay the groundwork as the basis of our first-in-human clinical trials of the non-viral SB system for the investigational treatment of CD19+ B-cell malignancies (currently under three INDs #: 14193, 14577, and 14739). PMID:23377665

  18. High-performance radial AMTEC cell design for ultra-high-power solar AMTEC systems

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, T.J.; Huang, C.

    1999-07-01

    Alkali Metal Thermal to Electric Conversion (AMTEC) technology is rapidly maturing for potential application in ultra-high-power solar AMTEC systems required by potential future US Air Force (USAF) spacecraft missions in medium-earth and geosynchronous orbits (MEO and GEO). Solar thermal AMTEC power systems potentially have several important advantages over current solar photovoltaic power systems in ultra-high-power spacecraft applications for USAF MEO and GEO missions. This work presents key aspects of radial AMTEC cell design to achieve high cell performance in solar AMTEC systems delivering larger than 50 kW(e) to support high power USAF missions. These missions typically require AMTEC cell conversion efficiency larger than 25%. A sophisticated design parameter methodology is described and demonstrated which establishes optimum design parameters in any radial cell design to satisfy high-power mission requirements. Specific relationships, which are distinct functions of cell temperatures and pressures, define critical dependencies between key cell design parameters, particularly the impact of parasitic thermal losses on Beta Alumina Solid Electrolyte (BASE) area requirements, voltage, number of BASE tubes, and system power production for both maximum power-per-BASE-area and optimum efficiency conditions. Finally, some high-level system tradeoffs are demonstrated using the design parameter methodology to establish high-power radial cell design requirements and philosophy. The discussion highlights how to incorporate this methodology with sophisticated SINDA/FLUINT AMTEC cell modeling capabilities to determine optimum radial AMTEC cell designs.

  19. The thioredoxin system in breast cancer cell invasion and migration

    OpenAIRE

    Maneet Bhatia; Kelly L. McGrath; Giovanna Di Trapani; Pornpimol Charoentong; Fenil Shah; Mallory M. King; Clarke, Frank M.; Tonissen, Kathryn F

    2016-01-01

    Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient ...

  20. Description and modelling of the solar-hydrogen-biogas-fuel cell system in GlashusEtt

    Science.gov (United States)

    Hedström, L.; Wallmark, C.; Alvfors, P.; Rissanen, M.; Stridh, B.; Ekman, J.

    The need to reduce pollutant emissions and utilise the world's available energy resources more efficiently has led to increased attention towards e.g. fuel cells, but also to other alternative energy solutions. In order to further understand and evaluate the prerequisites for sustainable and energy-saving systems, ABB and Fortum have equipped an environmental information centre, located in Hammarby Sjöstad, Stockholm, Sweden, with an alternative energy system. The system is being used to demonstrate and evaluate how a system based on fuel cells and solar cells can function as a complement to existing electricity and heat production. The stationary energy system is situated on the top level of a three-floor glass building and is open to the public. The alternative energy system consists of a fuel cell system, a photovoltaic (PV) cell array, an electrolyser, hydrogen storage tanks, a biogas burner, dc/ac inverters, heat exchangers and an accumulator tank. The fuel cell system includes a reformer and a polymer electrolyte fuel cell (PEFC) with a maximum rated electrical output of 4 kW el and a maximum thermal output of 6.5 kW th. The fuel cell stack can be operated with reformed biogas, or directly using hydrogen produced by the electrolyser. The cell stack in the electrolyser consists of proton exchange membrane (PEM) cells. To evaluate different automatic control strategies for the system, a simplified dynamic model has been developed in MATLAB Simulink. The model based on measurement data taken from the actual system. The evaluation is based on demand curves, investment costs, electricity prices and irradiation. Evaluation criteria included in the model are electrical and total efficiencies as well as economic parameters.

  1. Systemic Sclerosis Patients Present Alterations in the Expression of Molecules Involved in B-Cell Regulation

    Science.gov (United States)

    Soto, Lilian; Ferrier, Ashley; Aravena, Octavio; Fonseca, Elianet; Berendsen, Jorge; Biere, Andrea; Bueno, Daniel; Ramos, Verónica; Aguillón, Juan Carlos; Catalán, Diego

    2015-01-01

    The activation threshold of B cells is tightly regulated by an array of inhibitory and activator receptors in such a way that disturbances in their expression can lead to the appearance of autoimmunity. The aim of this study was to evaluate the expression of activating and inhibitory molecules involved in the modulation of B cell functions in transitional, naive, and memory B-cell subpopulations from systemic sclerosis patients. To achieve this, blood samples were drawn from 31 systemic sclerosis patients and 53 healthy individuals. Surface expression of CD86, MHC II, CD19, CD21, CD40, CD22, Siglec 10, CD35, and FcγRIIB was determined by flow cytometry. IL-10 production was evaluated by intracellular flow cytometry from isolated B cells. Soluble IL-6 and IL-10 levels were measured by ELISA from supernatants of stimulated B cells. Systemic sclerosis patients exhibit an increased frequency of transitional and naive B cells related to memory B cells compared with healthy controls. Transitional and naive B cells from patients express higher levels of CD86 and FcγRIIB than healthy donors. Also, B cells from patients show high expression of CD19 and CD40, whereas memory cells from systemic sclerosis patients show reduced expression of CD35. CD19 and CD35 expression levels associate with different autoantibody profiles. IL-10+ B cells and secreted levels of IL-10 were markedly reduced in patients. In conclusion, systemic sclerosis patients show alterations in the expression of molecules involved in B-cell regulation. These abnormalities may be determinant in the B-cell hyperactivation observed in systemic sclerosis. PMID:26483788

  2. Integration of B cells and CD8+ T in the protective regulation of systemic epithelial inflammation

    Science.gov (United States)

    Wei, Bo; McPherson, Michael; Turovskaya, Olga; Velazquez, Peter; Fujiwara, Daisuke; Brewer, Sarah; Braun, Jonathan

    2008-01-01

    Mechanisms that control abnormal CD4+ T cell-mediated tissue damage are a significant factor in averting and resolving chronic inflammatory epithelial diseases. B cells can promote such immunoregulation, and this is thought to involve interaction with MHC II- or CD1-restricted regulatory T cells. The purpose of this study is to genetically define the interacting cells targeted by protective B cells, and to elucidate their regulatory mechanisms in CD4+ T cell inflammation. Transfer of Gαi2−/− CD3+ T cells into lymphopenic mice causes a dose-dependent multi-organ inflammatory disease including the skin, intestine, and lungs. Disease activity is associated with elevated levels of serum TNF-α and IFN-γ and an activated IL-17 producing CD4+ T cell population. Mesenteric node B cells from wild type mice suppress disease activity, serum cytokine expression, and levels of CD4+ T cells producing TNF-α, IFN-γ, and IL-17. The protective function of B cells requires genetic sufficiency of IL-10, MHC I and TAP1. Regulatory B cells induce the expansion and activation of CD8+ T cells, which is correlated with disease protection. These results demonstrate that CD8+ T cells can ameliorate lymphopenic systemic inflammatory disease, through peptide/MHC I-dependent B cell interaction. PMID:18282744

  3. Performance study of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal system

    International Nuclear Information System (INIS)

    Highlights: → The performances of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal (TCPV/T) system have been studied. → The optimum concentration ratios for the single crystalline silicon cell, the Super cells and the GaAs cells were studied by experiments. → The influences between the solar cell's performance and the series resistances, the working temperature, solar irradiation intensity were explored. - Abstract: The performances of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal (TCPV/T) system have been studied via both experiment and theoretical calculation. The I-V characteristics of the solar cell arrays and the output performances of the TCPV/T system demonstrated that among the investigated four types of solar cell arrays, the triple junction GaAs cells possessed good performance characteristics and the polysilicon cells exhibited poor performance characteristics under concentrating conditions. The optimum concentration ratios for the single crystalline silicon cell, the Super cells and the GaAs cells were also studied by experiments. The optimum concentration ratios for the single crystalline silicon cells and Super cells were 4.23 and 8.46 respectively, and the triple junction GaAs cells could work well at higher concentration ratio. Besides, some theoretical calculations and experiments were performed to explore the influences of the series resistances and the working temperature. When the series resistances Rs changed from 0 Ω to 1 Ω, the maximum power Pm of the single crystalline silicon, the polycrystalline silicon, the Super cell and the GaAs cell arrays decreased by 67.78%, 74.93%, 77.30% and 58.07% respectively. When the cell temperature increased by 1 K, the short circuit current of the four types of solar cell arrays decreased by 0.11818 A, 0.05364 A, 0.01387 A and 0.00215 A respectively. The research results demonstrated that the output performance of the solar cell arrays with lower series

  4. Characterization of Rat Hair Follicle Stem Cells Selected by Vario Magnetic Activated Cell Sorting System

    International Nuclear Information System (INIS)

    Hair follicle stem cells (HfSCs) play crucial roles in hair follicle morphogenesis and hair cycling. These stem cells are self-renewable and have the multi-lineage potential to generate epidermis, sebaceous glands, and hair follicle. The separation and identification of hair follicle stem cells are important for further research in stem cell biology. In this study, we report on the successful enrichment of rat hair follicle stem cells through vario magnetic activated cell sorting (Vario MACS) and the biological characteristics of the stem cells. We chose the HfSCs positive surface markers CD34, α6-integrin and the negative marker CD71 to design four isolation strategies: positive selection with single marker of CD34, positive selection with single marker of α6-integrin, CD71 depletion followed by CD34 positive selection, and CD71 depletion followed by α6-integrin positive selection. The results of flow cytometry analysis showed that all four strategies had ideal effects. Specifically, we conducted a series of researches on HfSCs characterized by their high level of CD34, termed CD34bri cells, and low to undetectable expression of CD34, termed CD34dim cells. CD34bri cells had greater proliferative potential and higher colony-forming ability than CD34dim cells. Furthermore, CD34bri cells had some typical characteristics as progenitor cells, such as large nucleus, obvious nucleolus, large nuclear:cytoplasmic ratio and few cytoplasmic organelles. Our findings clearly demonstrated that HfSCs with high purity and viability could be successfully enriched with Vario MACS

  5. Advanced Space Power Systems (ASPS): Regenerative Fuel Cells (RFC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the regenerative fuel cell project element is to develop power and energy storage technologies that enable new capabilities for future human space...

  6. Modular PEM Fuel Cell System for Outdoor Applications

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, Mark; Haberman, David; Ibrahim, Samir; Lokken, Orrin; Dunn, Dan; Cherniack, Mark; Salter, Carlton [DCH Technology, Valencia, CA 91355 (United States); Stetson, Ned [Energy Conversion Devices, Troy, MI 48084 (United States)

    1999-10-01

    In this paper we discuss small proton exchange membrane (PEM) fuel cells that are well-suited to providing electrical power for many outdoor and portable applications. By utilizing a design that does not require any active components such as pumps, compressors, fans or blowers we are able to achieve high efficiencies and extremely reliable operation in a rugged, quiet and lightweight package. The fuel cell runs on hydrogen gas which reacts with oxygen from the air to produce electricity and water vapor. There are absolutely no emissions other than pure water vapor so the fuel cell is truly a `zero emissions` device. If larger amounts of power are desired for portable or stationary applications the modular fuel cells can be easily combined in parallel or series to produce the required voltage and current. (author) 6 refs., 1 tab., 9 figs.

  7. General Information About Childhood Central Nervous System Germ Cell Tumors

    Science.gov (United States)

    ... germ cell tumors to form is near the pineal gland and in an area of the brain that ... of the inside of the brain, showing the pineal and pituitary glands, optic nerve, ventricles (with cerebrospinal fluid shown in ...

  8. Hydrogen and fuel cells - The clean energy system

    Science.gov (United States)

    Rohland, B.; Nitsch, J.; Wendt, H.

    1992-01-01

    A strategy where hydrogen is effectively converted into useful energies like electricity and heat by fuel cells in the cogeneration mode is presented. A scenario is presented where renewable energies are used in an extensive but technologically achievable way. Renewable shares of 13 percent (2005), 36 percent (2025), and 69 percent (2050) on the total energy demand will lead to hydrogen shares of 11 percent in 2025 and 34 percent in 2050. Fuel cells provide high conversion efficiencies with respect to electricity and make it possible to use waste heat at different temperature levels. Low- and medium temperature fuel cells using pure hydrogen and high-temperature fuel cells for a mixed biogas-hydrogen conversion with a high energy yield are discussed.

  9. Systems biology and metabolic engineering of Arthrospira cell factories

    OpenAIRE

    Amornpan Klanchui; Tayvich Vorapreeda; Wanwipa Vongsangnak; Chiraphan Kannapho; Supapon Cheevadhanarak; Asawin Meechai

    2012-01-01

    Arthrospira are attractive candidates to serve as cell factories for production of many valuable compounds useful for food, feed, fuel and pharmaceutical industries. In connection with the development of sustainable bioprocessing, it is a challenge to design and develop efficient Arthrospira cell factories which can certify effective conversion from the raw materials (i.e. CO2 and sun light) into desired products. With the current availability of the genome sequences and metabolic models of A...

  10. Surface charge characteristics of cells from malignant cell lines and normal cell lines of the human hematopoietic system.

    Science.gov (United States)

    Marikovsky, Y; Ben-Bassat, H; Leibovich, S J; Cividalli, L; Fischler, H; Danon, D

    1979-02-01

    Cells from malignant and normal lines of human hematopoietic origin were studied for their surface charge characteristics with the use of the following criteria: 1) the electron microscopic appearance of cell membranes after labeling with cationized ferritin (CF) either before or after glutaraldehyde fixation, 2) electrophoretic mobility, 3) total sialic acid content, and 4) agglutinability with poly-L-lysine (PLL). CF induced a time-dependent redistribution of surface receptors in unfixed malignant cells but not in unfixed normal cells. After 10 seconds of labeling with CF, both normal and malignant unfixed cells showed a uniform and even labeling pattern. After 5 minutes of labeling, malignant cells exhibited a highly pronounced pattern of clusters and patches, as distinct from a random and even pattern exhibited by normal cells. Both normal and malignant cells after fixation exhibited an equivalent random and even labeling pattern with CF, independent of the duration of labeling. The malignant cells studied possessed less sialic acid, had a lower electric mobility, and were agglutinated more readily with PLL than were the normal cells. PMID:310907

  11. Changes in cell adhesion molecule expression on T cells associated with systemic virus infection

    DEFF Research Database (Denmark)

    Andersson, E C; Christensen, Jan Pravsgaard; Marker, O;

    1994-01-01

    -4, LFA-1, and ICAM-1, are up-regulated on CD8+ cells, whereas the lymph node homing receptor MEL-14 is down-regulated during the infection; only marginal changes were observed for CD4+ cells. Basically similar but less marked results were obtained in mice infected with Pichinde virus. Further......, it was found that up-regulation of VLA-4 expression on splenic T cells correlated with influx of inflammatory cells into the cerebrospinal fluid of intracerebrally infected animals, and that the number of CD8+VLA-4hi cells increased from lymph nodes and spleen to blood and cerebrospinal fluid. These...... results support the hypothesis that up-regulation of VLA-4 is important for effector T cell homing to sites of inflammation....

  12. Immunosuppression after sepsis: systemic inflammation and sepsis induce a loss of naive T-cells but no enduring cell-autonomous defects in T-cell function.

    Directory of Open Access Journals (Sweden)

    Robby Markwart

    Full Text Available Sepsis describes the life-threatening systemic inflammatory response (SIRS of an organism to an infection and is the leading cause of mortality on intensive care units (ICU worldwide. An acute episode of sepsis is characterized by the extensive release of cytokines and other mediators resulting in a dysregulated immune response leading to organ damage and/or death. This initial pro-inflammatory burst often transits into a state of immune suppression characterised by loss of immune cells and T-cell dysfunction at later disease stages in sepsis survivors. However, despite these appreciations, the precise nature of the evoked defect in T-cell immunity in post-acute phases of SIRS remains unknown. Here we present an in-depth functional analysis of T-cell function in post-acute SIRS/sepsis. We document that T-cell function is not compromised on a per cell basis in experimental rodent models of infection-free SIRS (LPS or CpG or septic peritonitis. Transgenic antigen-specific T-cells feature an unaltered cytokine response if challenged in vivo and ex vivo with cognate antigens. Isolated CD4(+/CD8(+ T-cells from post-acute septic animals do not exhibit defects in T-cell receptor-mediated activation at the the level of receptor-proximal signalling, activation marker upregulation or expansion. However, SIRS/sepsis induced transient lymphopenia and gave rise to an environment of immune attenuation at post acute disease stages. Thus, systemic inflammation has an acute impact on T-cell numbers and adaptive immunity, but does not cause major cell-autonomous enduring functional defects in T-cells.

  13. Optimization and Evaluation of a Novel Size Based Circulating Tumor Cell Isolation System.

    Science.gov (United States)

    Xu, Lei; Mao, Xueying; Imrali, Ahmet; Syed, Ferrial; Mutsvangwa, Katherine; Berney, Daniel; Cathcart, Paul; Hines, John; Shamash, Jonathan; Lu, Yong-Jie

    2015-01-01

    Isolation of circulating tumor cells (CTCs) from peripheral blood has the potential to provide a far easier "liquid biopsy" than tumor tissue biopsies, to monitor tumor cell populations during disease progression and in response to therapies. Many CTC isolation technologies have been developed. We optimized the Parsortix system, an epitope independent, size and compressibility-based platform for CTCs isolation, making it possible to harvest CTCs at the speed and sample volume comparable to standard CellSearch system. We captured more than half of cancer cells from different cancer cell lines spiked in blood samples from healthy donors using this system. Cell loss during immunostaining of cells transferred and fixed on the slides is a major problem for analyzing rare cell samples. We developed a novel cell transfer and fixation method to retain >90% of cells on the slide after the immunofluorescence process without affecting signal strength and specificity. Using this optimized method, we evaluated the Parsortix system for CTC harvest in prostate cancer patients in comparison to immunobead based CTC isolation systems IsoFlux and CellSearch. We harvested a similar number (p = 0.33) of cytokeratin (CK) positive CTCs using Parsortix and IsoFlux from 7.5 mL blood samples of 10 prostate cancer patients (an average of 33.8 and 37.6 respectively). The purity of the CTCs harvested by Parsortix at 3.1% was significantly higher than IsoFlux at 1.0% (p = 0.02). Parsortix harvested significantly more CK positive CTCs than CellSearch (p = 0.04) in seven prostate cancer patient samples, where both systems were utilized (an average of 32.1 and 10.1 respectively). We also captured CTC clusters using Parsortix. Using four-color immunofluorescence we found that 85.8% of PC3 cells expressed EpCAM, 91.7% expressed CK and 2.5% cells lacked both epithelial markers. Interestingly, 95.6% of PC3 cells expressed Vimentin, including those cells that lacked both epithelial marker expression

  14. Optimization and Evaluation of a Novel Size Based Circulating Tumor Cell Isolation System.

    Directory of Open Access Journals (Sweden)

    Lei Xu

    Full Text Available Isolation of circulating tumor cells (CTCs from peripheral blood has the potential to provide a far easier "liquid biopsy" than tumor tissue biopsies, to monitor tumor cell populations during disease progression and in response to therapies. Many CTC isolation technologies have been developed. We optimized the Parsortix system, an epitope independent, size and compressibility-based platform for CTCs isolation, making it possible to harvest CTCs at the speed and sample volume comparable to standard CellSearch system. We captured more than half of cancer cells from different cancer cell lines spiked in blood samples from healthy donors using this system. Cell loss during immunostaining of cells transferred and fixed on the slides is a major problem for analyzing rare cell samples. We developed a novel cell transfer and fixation method to retain >90% of cells on the slide after the immunofluorescence process without affecting signal strength and specificity. Using this optimized method, we evaluated the Parsortix system for CTC harvest in prostate cancer patients in comparison to immunobead based CTC isolation systems IsoFlux and CellSearch. We harvested a similar number (p = 0.33 of cytokeratin (CK positive CTCs using Parsortix and IsoFlux from 7.5 mL blood samples of 10 prostate cancer patients (an average of 33.8 and 37.6 respectively. The purity of the CTCs harvested by Parsortix at 3.1% was significantly higher than IsoFlux at 1.0% (p = 0.02. Parsortix harvested significantly more CK positive CTCs than CellSearch (p = 0.04 in seven prostate cancer patient samples, where both systems were utilized (an average of 32.1 and 10.1 respectively. We also captured CTC clusters using Parsortix. Using four-color immunofluorescence we found that 85.8% of PC3 cells expressed EpCAM, 91.7% expressed CK and 2.5% cells lacked both epithelial markers. Interestingly, 95.6% of PC3 cells expressed Vimentin, including those cells that lacked both epithelial marker

  15. Border Cell Migration: A Model System for Live Imaging and Genetic Analysis of Collective Cell Movement

    OpenAIRE

    M Prasad; Wang, X; He, L.; Cai, D.; Montell, DJ

    2015-01-01

    © 2015, Springer Science+Business Media New York. Border cell migration in the Drosophila ovary has emerged as a genetically tractable model for studying collective cell movement. Over many years border cell migration was exclusively studied in fixed samples due to the inability to culture stage 9 egg chambers in vitro. Although culturing late-stage egg chambers was long feasible, stage 9 egg chambers survived only briefl y outside the female body. We identifi ed culture conditions that suppo...

  16. QSpec: online control and data analysis system for single-cell Raman spectroscopy

    Directory of Open Access Journals (Sweden)

    Lihui Ren

    2014-06-01

    Full Text Available Single-cell phenotyping is critical to the success of biological reductionism. Raman-activated cell sorting (RACS has shown promise in resolving the dynamics of living cells at the individual level and to uncover population heterogeneities in comparison to established approaches such as fluorescence-activated cell sorting (FACS. Given that the number of single-cells would be massive in any experiment, the power of Raman profiling technique for single-cell analysis would be fully utilized only when coupled with a high-throughput and intelligent process control and data analysis system. In this work, we established QSpec, an automatic system that supports high-throughput Raman-based single-cell phenotyping. Additionally, a single-cell Raman profile database has been established upon which data-mining could be applied to discover the heterogeneity among single-cells under different conditions. To test the effectiveness of this control and data analysis system, a sub-system was also developed to simulate the phenotypes of single-cells as well as the device features.

  17. Study on two-cell stimulated Brillouin scattering system with mixture medium

    Institute of Scientific and Technical Information of China (English)

    HASI; Wuliji

    2007-01-01

    In this paper,a method of choosing mixture medium in two-cell stimulated Brillouinscattering(SBS)system to improve the system performance is proposed.The Brillouin frequency shift(BFS)of mixture medium varies with the mixing ratio andthus the difference of the BFS between the two cells can be eliminated.The two-cellSBS system with acetone(C3H6O)in its generator cell and mixture liquid ofCCl4/C2Cl4 in its amplifier cell is investigated.The C3H6O has a high optical breakdown threshold and the mixture liquid of CCl4/C2Cl4 has a small absorption coeffi-cient and the same BFS as that of C3H6O when the volume fraction of CCl4 is 4%.Compared with two-cell SBS system with the same liquid(C2Cl4)or different liquid(C3H6O and C2Cl4)in generator and amplifier cell,the SBS system with mixture liq-uid(CCl4/C2Cl4)in amplifier cell and C3H6O in generator cell improves thepower-load,energy reflectivity(ER),phase conjugation(PC)fidelity and ER stabil-ity.

  18. Study on two-cell stimulated Brillouin scattering system with mixture medium

    Institute of Scientific and Technical Information of China (English)

    HASI Wuliji; L(U) ZhiWei; LI Qiang; BA DeXin; HE WeiMing

    2007-01-01

    In this paper, a method of choosing mixture medium in two-cell stimulated Brillouin scattering (SBS) system to improve the system performance is proposed. The Brillouin frequency shift (BFS) of mixture medium varies with the mixing ratio and thus the difference of the BFS between the two cells can be eliminated. The two-cell SBS system with acetone (C3H6O) in its generator cell and mixture liquid of CCl4/C2Cl4 in its amplifier cell is investigated. The C3H6O has a high optical break- down threshold and the mixture liquid of CCl4/C2Cl4 has a small absorption coefficient and the same BFS as that of C3H6O when the volume fraction of CCl4 is 4%. Compared with two-cell SBS system with the same liquid (C2Cl4) or different liquid (C3H6O and C2Cl4) in generator and amplifier cell, the SBS system with mixture liquid (CCl4/C2Cl4) in amplifier cell and C3H6O in generator cell improves the power-load, energy reflectivity (ER), phase conjugation (PC) fidelity and ER stability.

  19. Biotechnological and biomedical applications of mesenchymal stem cells as a therapeutic system.

    Science.gov (United States)

    Rahimzadeh, Amirbahman; Tabatabaei Mirakabad, Fatemeh Sadat; Movassaghpour, Aliakbar; Shamsasenjan, Karim; Kariminekoo, Saber; Talebi, Mehdi; Shekari, Abolfazl; Zeighamian, Vahideh; Gandomkar Ghalhar, Masoud; Akbarzadeh, Abolfazl

    2016-03-01

    Mesenchymal stem cells (MSCs) are non-hematopoietic, multipotent progenitor cells which reside in bone marrow (BM), support homing of hematopoietic stem cells (HSCs) and self-renewal in the BM. These cells have the potential to differentiate into tissues of mesenchymal origin, such as fibroblasts, adipocytes, cardiomyocytes, and stromal cells. MSCs can express surface molecules like CD13, CD29, CD44, CD73, CD90, CD166, CXCL12 and toll-like receptors (TLRs). Different factors, such as TGF-β, IL-10, IDO, PGE-2, sHLA-G5, HO, and Galectin-3, secreted by MSCs, induce interaction in cell to cell immunomodulatory effects on innate and adaptive cells of the immune system. Furthermore, these cells can stimulate and increase the TH2 and regulatory T-cells through inhibitory effects on the immune system. MSCs originate from the BM and other tissues including the brain, adipose tissue, peripheral blood, cornea, thymus, spleen, fallopian tube, placenta, Wharton's jelly and umbilical cord blood. Many studies have focused on two significant features of MSC therapy: (I) MSCs can modulate T-cell-mediated immunological responses, and (II) systemically administered MSCs home in to sites of ischemia or injury. In this review, we describe the known mechanisms of immunomodulation and homing of MSCs. As a result, this review emphasizes the functional role of MSCs in modulating immune responses, their capability in homing to injured tissue, and their clinical therapeutic potential. PMID:25340260

  20. Hardware in the loop simulation test platform of fuel cell backup system

    OpenAIRE

    Ma Tiancai; Wang Fuxian; Xu Shi; Zhu Dong; Dai Yuanxing; Gu Rongxin

    2015-01-01

    Based on an analysis of voltage mechanistic model, a real-time simulation model of the proton exchange membrane (PEM) fuel cell backup system is developed, and verified by the measurable experiment data. The method of online parameters identification for the model is also improved. Based on the software LabVIEW/VeriStand real-time environment and the PXI Express hardware system, the PEM fuel cell system controller hardware in the loop (HIL) simulation plat-form is established. Controller simu...

  1. Incubator embedded cell culture imaging system (EmSight) based on Fourier ptychographic microscopy

    OpenAIRE

    Kim, Jinho; Henley, Beverley M.; Kim, Charlene H.; Lester, Henry A.; Yang, Changhuei

    2016-01-01

    Multi-day tracking of cells in culture systems can provide valuable information in bioscience experiments. We report the development of a cell culture imaging system, named EmSight, which incorporates multiple compact Fourier ptychographic microscopes with a standard multiwell imaging plate. The system is housed in an incubator and presently incorporates six microscopes. By using the same low magnification objective lenses as the objective and the tube lens, the EmSight is configured as a 1:1...

  2. Intelligent Power Management of hybrid Wind/ Fuel Cell/ Energy Storage Power Generation System

    OpenAIRE

    A. Hajizadeh; Hassanzadeh, F.

    2013-01-01

    This paper presents an intelligent power management strategy for hybrid wind/ fuel cell/ energy storage power generation system. The dynamic models of wind turbine, fuel cell and energy storage have been used for simulation of hybrid power system. In order to design power flow control strategy, a fuzzy logic control has been implemented to manage the power between power sources. The optimal operation of the hybrid power system is a main goal of designing power management strategy. The hybrid ...

  3. IMAGING OF THE INTERACTION OF CANCER CELLS AND THE LYMPHATIC SYSTEM

    OpenAIRE

    Tran Cao, Hop S.; McElroy, Michele; Kaushal, Sharmeela; Robert M. Hoffman; Bouvet, Michael

    2011-01-01

    A thorough understanding of the lymphatic system and its interaction with cancer cells is crucial to our ability to fight cancer metastasis. Efforts to study the lymphatic system had previously been limited by the inability to visualize the lymphatic system in vivo in real time. Fluorescence imaging can address these limitations and allow for visualization of lymphatic delivery and trafficking of cancer cells and possibly therapeutic agents as well. Here, we review recent articles in which an...

  4. Cre Reporter System To Monitor the Translocation of Type III Secreted Proteins into Host Cells

    OpenAIRE

    Briones, Gabriel; Hofreuter, Dirk; Galán, Jorge E.

    2006-01-01

    Central to the study of type III secretion systems is the availability of reporter systems to monitor bacterial protein translocation into host cells. We report here the development of a bacteriophage P1 Cre recombinase-based system to monitor the translocation of bacterial proteins into mammalian cells. Bacteriophage P1 Cre recombinase fused to the secretion and translocation signals of Salmonella enterica serovar Typhimurium of the type III secreted protein SopE was secreted in a type III s...

  5. A cell counting/sorting system incorporated with a microfabricated flow cytometer chip

    Science.gov (United States)

    Yang, Sung-Yi; Hsiung, Suz-Kai; Hung, Yung-Ching; Chang, Chen-Min; Liao, Teh-Lu; Lee, Gwo-Bin

    2006-07-01

    Flow cytometry is a popular technique for counting and sorting individual cells. This study presents and demonstrates a new cell counting/sorting system integrated with several essential components including a micromachined flow cytometer chip device, an optical detection system and a data analysis and control system to achieve the functions of cell sample injection, optical signal detection and cell collection. By using MEMS technology, we have integrated several microfluidic components such as micro pneumatic pumps/valves onto a polymer-based chip device. Three pneumatic micropumps are used to provide the hydrodynamic driving force for both sample and sheath flows such that hydrodynamic flow focusing can be achieved, and a micro flow switch device comprising three pneumatic microvalves located downstream of the micro sample flow channel is used for cell collection. Cell samples of human lung cancer cells labelled with commercially available fluorescent dyes have been detected and collected successfully utilizing the developed device. The real-time image of dye-labelled cell samples being excited and detected can be monitored and observed through the LCD panel by a custom designed CCD/APD holder and moving stage. Finally, micro flow switch devices were used to successfully sort the cells into the desired outlet channel, and the counting results of the specific cell samples were monitored through the counting panel. The current study focuses on the setup of the overall system. The proposed flow cytometer system has several advantages such as portability, low cost and easy operation process. The size of the system is 37 cm × 16 cm × 18 cm and the weight is 3.5 kg. The error rate of counting and sorting was 1.5% and 2%, respectively. The sorting frequency of the microvalve device is calculated to be 120 cells min-1. The developed microfluidic chip device could be a promising tool for cell-based application fields such as profiling, counting and sorting.

  6. Development of an energy consumption and cost data base for fuel cell total energy systems and conventional building energy systems

    Science.gov (United States)

    Pine, G. D.; Christian, J. E.; Mixon, W. R.; Jackson, W. L.

    1980-07-01

    The procedures and data sources used to develop an energy consumption and system cost data base for use in predicting the market penetration of phosphoric acid fuel cell total energy systems in the nonindustrial building market are described. A computer program was used to simulate the hourly energy requirements of six types of buildings; office buildings; retail stores; hotels and motels; schools; hospitals; and multifamily residences. The simulations were done by using hourly weather tapes for one city in each of the ten Department of Energy administrative regions. Two types of building construction were considered, one for existing buildings and one for new buildings. A fuel cell system combined with electrically driven heat pumps and one combined with a gas boiler and an electrically driven chiller were compared with similar conventional systems. The methods of system simulation, component sizing, and system cost estimation are described for each system.

  7. An Easy-to-Use Polystyrene Microchip-based Cell Culture System.

    Science.gov (United States)

    Tazawa, Hidekatsu; Sunaoshi, Shohei; Tokeshi, Manabu; Kitamori, Takehiko; Ohtani-Kaneko, Ritsuko

    2016-01-01

    In this study, we developed an integrated, low-cost microfluidic cell culture system that is easy to use. This system consists of a disposable polystyrene microchip, a polytetrafluoroethylene valve, an air bubble trap, and an indium tin oxide temperature controller. Valve pressure resistance was validated with a manometer to be 3 MPa. The trap protected against bubble contamination. The temperature controller enabled the culture of Macaca mulatta RF/6A 135 vascular endothelial cells, which are difficult to culture in glass microchips, without a CO2 incubator. We determined the optimal coating conditions for these cells and were able to achieve stable, confluent culture within 1 week. This practical system is suitable for low-cost screening and has potential applications as circulatory cell culture systems and research platforms in cell biology. PMID:26960617

  8. Characterisation of a hybrid, fuel-cell-based propulsion system for small unmanned aircraft

    Science.gov (United States)

    Verstraete, D.; Lehmkuehler, K.; Gong, A.; Harvey, J. R.; Brian, G.; Palmer, J. L.

    2014-03-01

    Advanced hybrid powerplants combining a fuel cell and battery can enable significantly higher endurance for small, electrically powered unmanned aircraft systems, compared with batteries alone. However, detailed investigations of the static and dynamic performance of such systems are required to address integration challenges. This article describes a series of tests used to characterise the Horizon Energy Systems' AeroStack hybrid, fuel-cell-based powertrain. The results demonstrate that a significant difference can exist between the dynamic performance of the fuel-cell system and its static polarisation curve, confirming the need for detailed measurements. The results also confirm that the AeroStack's lithium-polymer battery plays a crucial role in its response to dynamic load changes and protects the fuel cell from membrane dehydration and fuel starvation. At low static loads, the AeroStack fuel cell recharges the battery with currents up to 1 A, which leads to further differences with the polarisation curve.

  9. LEYDIG CELLS AS A MODEL OF MALE REPRODUCTIVE SYSTEM

    Directory of Open Access Journals (Sweden)

    Tomáš Jambor

    2014-02-01

    Full Text Available During the past decades, a large anount of information concerning the infertility, which can be caused by malfunction at the level of sperm or production of testosterone was published. It is about androgene which is from 95 percent synthetized in testes. It plays significant role in development of individual´s sexual signs and is also the starter of spermatogenesis. The main mechanism ensuring the production of this important hormone is the process determined as a steroidogenesis. This process runs in cells located in testes and are known as Leydig cells (LC. Several types of LC are classified as for example fetal, adult, stem, progenitor or immature cells. There are mutual differences, but their common feature is a production of androgenes. Mitochondria and endoplasmic reticulum have irreplaceable position within LC and they, together with relevant enzymes and cascades of reactions, ensure the metamorphosis of cholesterol up to testosterone. With rising age the activity of steroidogenesis declines what is, however, natural. But there are many cases when this process in cells of developing individual is impaired by external or internal factors. Their identification and consequent elimination is for sufficient production of testosterone very important. This review contains on overview of Leydig cell biology and testosterone synthesis.

  10. Nestin Reporter Transgene Labels Multiple Central Nervous System Precursor Cells

    Directory of Open Access Journals (Sweden)

    Avery S. Walker

    2010-01-01

    Full Text Available Embryonic neuroepithelia and adult subventricular zone (SVZ stem and progenitor cells express nestin. We characterized a transgenic line that expresses enhanced green fluorescent protein (eGFP specified to neural tissue by the second intronic enhancer of the nestin promoter that had several novel features. During embryogenesis, the dorsal telencephalon contained many and the ventral telencephalon few eGFP+ cells. eGFP+ cells were found in postnatal and adult neurogenic regions. eGFP+ cells in the SVZ expressed multiple phenotype markers, glial fibrillary acidic protein, Dlx, and neuroblast-specific molecules suggesting the transgene is expressed through the lineage. eGFP+ cell numbers increased in the SVZ after cortical injury, suggesting this line will be useful in probing postinjury neurogenesis. In non-neurogenic regions, eGFP was strongly expressed in oligodendrocyte progenitors, but not in astrocytes, even when they were reactive. This eGFP+ mouse will facilitate studies of proliferative neuroepithelia and adult neurogenesis, as well as of parenchymal oligodendrocytes.

  11. Redefining plant systems biology: from cell to ecosystem

    NARCIS (Netherlands)

    Keurentjes, J.J.B.; Angenent, G.C.; Dicke, M.; Martins Dos Santos, V.A.P.; Molenaar, J.; Putten, van der W.H.; Ruiter, de P.C.; Struik, P.C.; Thomma, B.

    2011-01-01

    Molecular biologists typically restrict systems biology to cellular levels. By contrast, ecologists define biological systems as communities of interacting individuals at different trophic levels that process energy, nutrient and information flows. Modern plant breeding needs to increase agricultura

  12. Multilineage differentiation of rhesus monkey embryonic stem cells in three-dimensional culture systems

    Science.gov (United States)

    Chen, Silvia S.; Revoltella, Roberto P.; Papini, Sandra; Michelini, Monica; Fitzgerald, Wendy; Zimmerberg, Joshua; Margolis, Leonid

    2003-01-01

    In the course of normal embryogenesis, embryonic stem (ES) cells differentiate along different lineages in the context of complex three-dimensional (3D) tissue structures. In order to study this phenomenon in vitro under controlled conditions, 3D culture systems are necessary. Here, we studied in vitro differentiation of rhesus monkey ES cells in 3D collagen matrixes (collagen gels and porous collagen sponges). Differentiation of ES cells in these 3D systems was different from that in monolayers. ES cells differentiated in collagen matrixes into neural, epithelial, and endothelial lineages. The abilities of ES cells to form various structures in two chemically similar but topologically different matrixes were different. In particular, in collagen gels ES cells formed gland-like circular structures, whereas in collagen sponges ES cells were scattered through the matrix or formed aggregates. Soluble factors produced by feeder cells or added to the culture medium facilitated ES cell differentiation into particular lineages. Coculture with fibroblasts in collagen gel facilitated ES cell differentiation into cells of a neural lineage expressing nestin, neural cell adhesion molecule, and class III beta-tubulin. In collagen sponges, keratinocytes facilitated ES cell differentiation into cells of an endothelial lineage expressing factor VIII. Exogenous granulocyte-macrophage colony-stimulating factor further enhanced endothelial differentiation. Thus, both soluble factors and the type of extracellular matrix seem to be critical in directing differentiation of ES cells and the formation of tissue-like structures. Three-dimensional culture systems are a valuable tool for studying the mechanisms of these phenomena.

  13. Characterization of Ethanol Production from Xylose and Xylitol by a Cell-Free Pachysolen tannophilus System

    OpenAIRE

    Xu, Jie; Taylor, Kenneth B.

    1993-01-01

    Whole cells and a cell extract of Pachysolen tannophilus converted xylose to xylitol, ethanol, and CO2. The whole-cell system converted xylitol slowly to CO2 and little ethanol was produced, whereas the cell-free system converted xylitol quantitatively to ethanol (1.64 mol of ethanol per mol of xylitol) and CO2. The supernatant solution from high-speed centrifugation (100,000 × g) of the extract converted xylose to ethanol, but did not metabolize xylitol unless a membrane fraction and oxygen ...

  14. Clinical applications of circulating tumor cells in lung cancer patients by CellSearch system

    Directory of Open Access Journals (Sweden)

    AnnaTruini

    2014-09-01

    In the present review the significance of CTC detection in lung cancer is examined through the analysis of the published studies in both non-small cell and small cell lung cancers; additionally the prognostic and the clinical role of CTC enumeration in treatment monitoring will be reported and discussed.

  15. Development of a PEM Fuel Cell City Bus with a Hierarchical Control System

    Directory of Open Access Journals (Sweden)

    Siliang Cheng

    2016-05-01

    Full Text Available The polymer electrolyte membrane (PEM fuel cell system is considered to be an ideal alternative for the internal combustion engine, especially when used on a city bus. Hybrid buses with fuel cell systems and energy storage systems are now undergoing transit service demonstrations worldwide. A hybrid PEM fuel cell city bus with a hierarchical control system is studied in this paper. Firstly, the powertrain and hierarchical control structure is introduced. Secondly, the vehicle control strategy including start-stop strategy, energy management strategy, and fuel cell control strategy, including the hydrogen system and air system control strategies, are described in detail. Finally, the performance of the fuel cell was analyzed based on road test data. Results showed that the different subsystems were well-coordinated. Each component functioned in concert in order to ensure that both safety and speed requirements were satisfied. The output current of the fuel cell system changed slowly and the output voltage was limited to a certain range, thereby enhancing durability of the fuel cell. Furthermore, the economic performance was optimized by avoiding low load conditions.

  16. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    Science.gov (United States)

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  17. Gas composition modeling in a reformed Methanol Fuel Cell system using adaptive Neuro-Fuzzy Inference Systems

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Shaker, Hamid Reza;

    2013-01-01

    This work presents a method for modeling the gas composition in a Reformed Methanol Fuel Cell system. The method is based on Adaptive Neuro-Fuzzy-Inference-Systems which are trained on experimental data. The developed models are of the H2, CO2, CO and CH3OH mass flows of the reformed gas. The ANFIS...

  18. Gamma Interferon Signaling in Macrophage Lineage Cells Regulates Central Nervous System Inflammation and Chemokine Production ▿

    OpenAIRE

    Lin, Adora A.; Tripathi, Pulak K.; Sholl, Allyson; Jordan, Michael B.; Hildeman, David A.

    2009-01-01

    Intracranial (i.c.) infection of mice with lymphocytic choriomeningitis virus (LCMV) results in anorexic weight loss, mediated by T cells and gamma interferon (IFN-γ). Here, we assessed the role of CD4+ T cells and IFN-γ on immune cell recruitment and proinflammatory cytokine/chemokine production in the central nervous system (CNS) after i.c. LCMV infection. We found that T-cell-depleted mice had decreased recruitment of hematopoietic cells to the CNS and diminished levels of IFN-γ, CCL2 (MCP...

  19. High Performance Fuel Cell and Electrolyzer Membrane Electrode Assemblies (MEAs) for Space Energy Storage Systems

    Science.gov (United States)

    Valdez, Thomas I.; Billings, Keith J.; Kisor, Adam; Bennett, William R.; Jakupca, Ian J.; Burke, Kenneth; Hoberecht, Mark A.

    2012-01-01

    Regenerative fuel cells provide a pathway to energy storage system development that are game changers for NASA missions. The fuel cell/ electrolysis MEA performance requirements 0.92 V/ 1.44 V at 200 mA/cm2 can be met. Fuel Cell MEAs have been incorporated into advanced NFT stacks. Electrolyzer stack development in progress. Fuel Cell MEA performance is a strong function of membrane selection, membrane selection will be driven by durability requirements. Electrolyzer MEA performance is catalysts driven, catalyst selection will be driven by durability requirements. Round Trip Efficiency, based on a cell performance, is approximately 65%.

  20. Carbon dioxide electrolysis with solid oxide electrolyte cells for oxygen recovery in life support systems

    Science.gov (United States)

    Isenberg, Arnold O.; Cusick, Robert J.

    1988-01-01

    The direct electrochemical reduction of carbon dioxide (CO2) is achieved without catalysts and at sufficiently high temperatures to avoid carbon formation. The tubular electrolysis cell consists of thin layers of anode, electrolyte, cathode and cell interconnection. The electrolyte is made from yttria-stabilized zirconia which is an oxygen ion conductor at elevated temperatures. Anode and cell interconnection materials are complex oxides and are electronic conductors. The cathode material is a composite metal-ceramic structure. Cell performance characteristics have been determined using varying feed gas compositions and degrees of electrochemical decomposition. Cell test data are used to project the performance of a three-person CO2-electrolysis breadboard system.

  1. Use of Trypan blue-Arabinose System in Photogalvanic Cell for Solar Energy Conversion and Storage

    OpenAIRE

    K. M. Gangotri*; Mohan Lal

    2014-01-01

    Photogalvanic effect was studied in the cell containing Trypan blue as photosensitizer in Arabinose-NaOH system. The conversion efficiency of the cell, fill factor and the cell performance were observed 0.80%, 0.23 and 140.0 minutes in dark respectively. The effects of different parameters on the electrical output of the cell were observed and current-voltage (i–V) characteristics of the cell were also studies. The photopotential and photocurrent were observed as 834 mV and 35...

  2. FOXP3 positive regulatory T-cells in cutaneous and systemic CD30 positive T-cell lymphoproliferations

    DEFF Research Database (Denmark)

    Gjerdrum, Lise Mette; Woetmann, Anders; Ødum, Niels;

    2008-01-01

    -cells (Tregs) may be implicated. In this study, skin biopsies from lymphomatoid papulosis (LyP) (n = 14), primary cutaneous anaplastic large cells lymphoma (C-ALCL) (n = 13) and systemic anaplastic large cells lymphoma (S-ALCL) with (n = 9) or without (n = 6) ALK expression were examined by immunohistology for...... FOXP3 expression in tumour cells and tumour infiltrating Tregs. Labelling of a majority of the neoplastic cells was seen in one case of C-ALCL. Another three cases (one LyP and two C-ALCL) displayed weak labelling of very occasional atypical T-cells. In the remaining 38 cases the atypical lymphoid...... infiltrate was FOXP3 negative. By contrast, all biopsies contained tumour infiltrating FOXP3-positive Tregs. Significant higher numbers were recorded in ALK negative S-ALCL and LyP than in C-ALCL and S-ALCL positive for ALK. In conclusion, it is shown that FOXP3 expression in cutaneous and systemic CD30...

  3. Design and Comparison of Power Systems for a Fuel Cell Hybrid Electric Vehicle

    DEFF Research Database (Denmark)

    Schaltz, Erik; Rasmussen, Peter Omand

    2008-01-01

    In a fuel cell hybrid electric vehicle (FCHEV) the fuel cell stack is assisted by one or more energy storage devices. Thereby the system cost, mass, and volume can be decreased, and a significant better performance can be obtained. Two often used energy storage devices are the battery and...... ultracapacitors are the only energy storage device the system becomes too big and heavy. A fuel cell/battery/ultracapacitor hybrid provides the longest life time of the batteries. If the fuel cell stack power is too small, the system will be big, heavy, and have a poor efficiency....... ultracapacitor. In this paper a design method to design the power system of a FCHEV is presented. 10 cases of combining the fuel stack with either the battery, ultracapacitor, or both are investigated. The system volume, mass, efficiency, and battery lifetime are also compared. It is concluded that when...

  4. GEM System: automatic prototyping of cell-wide metabolic pathway models from genomes

    Directory of Open Access Journals (Sweden)

    Nakayama Yoichi

    2006-03-01

    Full Text Available Abstract Background Successful realization of a "systems biology" approach to analyzing cells is a grand challenge for our understanding of life. However, current modeling approaches to cell simulation are labor-intensive, manual affairs, and therefore constitute a major bottleneck in the evolution of computational cell biology. Results We developed the Genome-based Modeling (GEM System for the purpose of automatically prototyping simulation models of cell-wide metabolic pathways from genome sequences and other public biological information. Models generated by the GEM System include an entire Escherichia coli metabolism model comprising 968 reactions of 1195 metabolites, achieving 100% coverage when compared with the KEGG database, 92.38% with the EcoCyc database, and 95.06% with iJR904 genome-scale model. Conclusion The GEM System prototypes qualitative models to reduce the labor-intensive tasks required for systems biology research. Models of over 90 bacterial genomes are available at our web site.

  5. Microgravity-induced alterations in signal transduction in cells of the immune system

    Science.gov (United States)

    Paulsen, Katrin; Thiel, Cora; Timm, Johanna; Schmidt, Peter M.; Huber, Kathrin; Tauber, Svantje; Hemmersbach, Ruth; Seibt, Dieter; Kroll, Hartmut; Grote, Karl-Heinrich; Zipp, Frauke; Schneider-Stock, Regine; Cogoli, Augusto; Hilliger, Andre; Engelmann, Frank; Ullrich, Oliver

    2010-11-01

    Since decades it is known that the activity of cells of the immune system is severely dysregulated in microgravity, however, the underlying molecular aspects have not been elucidated yet. The identification of gravity-sensitive molecular mechanisms in cells of the immune system is an important and indispensable prerequisite for the development of counteractive measures to prevent or treat disturbed immune cell function of astronauts during long-term space missions. Moreover, their sensitivity to altered gravity renders immune cells an ideal model system to understand if and how gravity on Earth is required for normal mammalian cell function and signal transduction. We investigated the effect of simulated weightlessness (2D clinostat) and of real microgravity (parabolic flights) on key signal pathways in a human monocytic and a T lymphocyte cell line. We found that cellular responses to microgravity strongly depend on the cell-type and the conditions in which the cells are subjected to microgravity. In Jurkat T cells, enhanced phosphorylation of the MAP kinases ERK-1/2, MEK and p38 and inhibition of nuclear translocation of NF-kB were the predominant responses to simulated weightlessness, in either stimulated or non-stimulated cells. In contrast, non-stimulated monocytic U937 cells responded to simulated weightlessness with enhanced overall tyrosine-phosphorylation and activation of c-jun, whereas PMA-stimulated U937 cells responded the opposite way with reduced tyrosine-phosphorylation and reduced activation of c-jun, compared with PMA-stimulated 1 g controls. P53 protein was phosphorylated rapidly in microgravity. The identification of gravi-sensitive mechanisms in cells of the immune system will not only enable us to understand and prevent the negative effects of long time exposure to microgravity on Astronauts, but could also lead to novel therapeutic targets in general.

  6. Fuel cells science and engineering. Materials, processes, systems and technology. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Stolten, Detlef; Emonts, Bernd (eds.) [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF), Brennstoffzellen (IEF-3)

    2012-07-01

    The second volume is divided in four parts and 19 chapters. It is structured as follows: PART V: Modeling and Simulation. Chapter 23: Messages from Analytical Modeling of Fuel Cells (Andrei Kulikovsky); 24: Stochastic Modeling of Fuel-Cell Components (Ralf Thiedmann, Gerd Gaiselmann, Werner Lehnert and Volker Schmidt); 25: Computational Fluid Dynamic Simulation Using Supercomputer Calculation Capacity (Ralf Peters and Florian Scharf); 26 Modeling Solid Oxide Fuel Cells from the Macroscale to the Nanoscale (Emily M. Ryan and Mohammad A. Khaleel); 27: Numerical Modeling of the Thermomechanically Induced Stress in Solid Oxide Fuel Cells (Murat Peksen); 28: Modeling of Molten Carbonate Fuel Cells (Peter Heidebrecht, Silvia Piewek and Kai Sundmacher); Chapter 29: High-Temperature Polymer Electrolyte Fuel-Cell Modeling (Uwe Reimer); Chapter 30: Modeling of Polymer Electrolyte Membrane Fuel-Cell Components (Yun Wang and Ken S. Chen); 31: Modeling of Polymer Electrolyte Membrane Fuel Cells and Stacks (Yun Wang and Ken S. Chen). PART VI: Balance of Plant Design and Components. Chapter 32: Principles of Systems Engineering (Ludger Blum, Ralf Peters and Remzi Can Samsun); 33: System Technology for Solid Oxide Fuel Cells (Nguyen Q. Minh); 34: Desulfurization for Fuel-Cell Systems (Joachim Pasel and Ralf Peters); 35: Design Criteria and Components for Fuel Cell Powertrains (Lutz Eckstein and Bruno Gnoerich); 36: Hybridization for Fuel Cells (Joerg Wilhelm). PART VII: Systems Verification and Market Introduction. Chapter 37: Off-Grid Power Supply and Premium Power Generation (Kerry-Ann Adamson); 38: Demonstration Projects and Market Introduction (Kristin Deason). PART VIII: Knowledge Distribution and Public Awareness. Chapter 39: A Sustainable Framework for International Collaboration: the IEA HIA and Its Strategic Plan for 2009-2015 (Mary-Rose de Valladares); 40: Overview of Fuel Cell and Hydrogen Organizations and Initiatives Worldwide (Bernd Emonts) 41: Contributions for

  7. Simple display system of mechanical properties of cells and their dispersion.

    Directory of Open Access Journals (Sweden)

    Yuji Shimizu

    Full Text Available The mechanical properties of cells are unique indicators of their states and functions. Though, it is difficult to recognize the degrees of mechanical properties, due to small size of the cell and broad distribution of the mechanical properties. Here, we developed a simple virtual reality system for presenting the mechanical properties of cells and their dispersion using a haptic device and a PC. This system simulates atomic force microscopy (AFM nanoindentation experiments for floating cells in virtual environments. An operator can virtually position the AFM spherical probe over a round cell with the haptic handle on the PC monitor and feel the force interaction. The Young's modulus of mesenchymal stem cells and HEK293 cells in the floating state was measured by AFM. The distribution of the Young's modulus of these cells was broad, and the distribution complied with a log-normal pattern. To represent the mechanical properties together with the cell variance, we used log-normal distribution-dependent random number determined by the mode and variance values of the Young's modulus of these cells. The represented Young's modulus was determined for each touching event of the probe surface and the cell object, and the haptic device-generating force was calculated using a Hertz model corresponding to the indentation depth and the fixed Young's modulus value. Using this system, we can feel the mechanical properties and their dispersion in each cell type in real time. This system will help us not only recognize the degrees of mechanical properties of diverse cells but also share them with others.

  8. Free water surface constructed wetlands for urban-industrial wastewater treatment; Utilizacion de humedales construidos de flujo superficial en el tratamiento de aguas residuales de origen urbano-industrial

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Garcia, M.; Cabezas Beaumont, A.; Comin Sebastian, F.

    2009-07-01

    In order to assay superficial flow wetlands efficiency in the urban-industrial mixed wastewater quality improve and their effect in its re valorization for potential reuse in irrigation, three Free Water Surface Flow Wetlands were studied. the system presents a high capacity to reduce TSS, nitrate, nitrite and NT concentrations and this efficiency was growing up as the system mature. Denitrification processes in sediment is the main cause of nitrogen elimination. On the other hand reeds biomass development during this period could be contributing to treatment efficiency by means of reeds nutrients assimilation. (Author) 25 refs.

  9. Similar disturbances in B cell activity and regulatory T cell function in Henoch-Schonlein purpura and systemic lupus erythematosus

    International Nuclear Information System (INIS)

    The immunoglobulin synthesizing activities of peripheral mononuclear cells (MNC) from five patients with Henoch-Schonlein purpura (HSP) and eight patients with active systemic lupus erythematosus (SLE) were compared. Cumulative amounts of IgM, IgG, and IgA synthesized and secreted by unstimulated and PWM-stimulated patient cells over a 12-day period were determied in a solid-phase radioimmunoassay. In unstimulated control cultures mean rates of IgM, IgG, and IgA synthesis were less than 250 ng/ml. The synthetic activities of patient MNC were markedly increased. In HSP cultures IgA was the major immunoglobulin class produced (2810 x/divide 1.33 ng/ml) followed by IgG (1754 x/divide 1.32 ng/ml) and IgM (404 x/divide 1.16 ng/ml). In SLE cultures IgA and IgG syntheses were equally elevated (4427 x/divide 1.20 and 4438 x/divide 1.49 ng/ml, respectively) whereas IgM synthesis averaged 967 x/divide 1.66 ng/ml. PWM stimulation of pateient MNC caused a sharp decline in the synthesis of all three immunoglobulin classes. After T cell depletion B cell-enriched fractions from HSP and SLE patients maintained high levels of IgA and IgG synthesis that were inhibited by PWM and by normal allogeneic but not autologous T cells. In PWM-stimulted co-cultures, patient T cells nonspecifically suppressed the synthetic activities of autologous and control B cells. in contrast patient B cells achieved normal levels of immunoglobulin synthesis when cultured with control T cells plus PWM. In longitudinal studies patient B and T cell disturbances persisted despite clinical improvement

  10. Fuel Cell Power Model Version 2: Startup Guide, System Designs, and Case Studies. Modeling Electricity, Heat, and Hydrogen Generation from Fuel Cell-Based Distributed Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Steward, D.; Penev, M.; Saur, G.; Becker, W.; Zuboy, J.

    2013-06-01

    This guide helps users get started with the U.S. Department of Energy/National Renewable Energy Laboratory Fuel Cell Power (FCPower) Model Version 2, which is a Microsoft Excel workbook that analyzes the technical and economic aspects of high-temperature fuel cell-based distributed energy systems with the aim of providing consistent, transparent, comparable results. This type of energy system would provide onsite-generated heat and electricity to large end users such as hospitals and office complexes. The hydrogen produced could be used for fueling vehicles or stored for later conversion to electricity.

  11. Fuel cell systems international situation and Italian programmes

    International Nuclear Information System (INIS)

    Among innovation technologies in the field of energy production, fuel cells are meeting with deep interest, thanks to their characteristics which are answering the purposed pursued in the electrical field i.e. improved efficiency in the primary sources conversion, flexibility in the use of the fuels and reduction of pollutant emissions in the atmosphere

  12. A versatile expression vector system for mammalian cell factories

    DEFF Research Database (Denmark)

    Lund, Anne Mathilde; Kildegaard, Helene Faustrup; Hansen, Bjarne Gram; Andersen, Mikael Rørdam; Mortensen, Uffe Hasbro

    The development of the field of mammalian cell factories requests fast and high-throughput methods which means high need for simpler and more efficient cloning techniques. This project applies the ligation-free USERTM (uracil-specific excision reagent) cloning technique to construct mammalian...... expression vectors with maximum flexibility....

  13. CEACAM1 mediates B cell aggregation in central nervous system autoimmunity.

    Science.gov (United States)

    Rovituso, Damiano M; Scheffler, Laura; Wunsch, Marie; Kleinschnitz, Christoph; Dörck, Sebastian; Ulzheimer, Jochen; Bayas, Antonios; Steinman, Lawrence; Ergün, Süleyman; Kuerten, Stefanie

    2016-01-01

    B cell aggregates in the central nervous system (CNS) have been associated with rapid disease progression in patients with multiple sclerosis (MS). Here we demonstrate a key role of carcinoembryogenic antigen-related cell adhesion molecule1 (CEACAM1) in B cell aggregate formation in MS patients and a B cell-dependent mouse model of MS. CEACAM1 expression was increased on peripheral blood B cells and CEACAM1(+) B cells were present in brain infiltrates of MS patients. Administration of the anti-CEACAM1 antibody T84.1 was efficient in blocking aggregation of B cells derived from MS patients. Along these lines, application of the monoclonal anti-CEACAM1 antibody mCC1 was able to inhibit CNS B cell aggregate formation and significantly attenuated established MS-like disease in mice in the absence of any adverse effects. CEACAM1 was co-expressed with the regulator molecule T cell immunoglobulin and mucin domain -3 (TIM-3) on B cells, a novel molecule that has recently been described to induce anergy in T cells. Interestingly, elevated coexpression on B cells coincided with an autoreactive T helper cell phenotype in MS patients. Overall, these data identify CEACAM1 as a clinically highly interesting target in MS pathogenesis and open new therapeutic avenues for the treatment of the disease. PMID:27435215

  14. Cover and startup gas supply system for solid oxide fuel cell generator

    Science.gov (United States)

    Singh, Prabhakar; George, Raymond A.

    1999-01-01

    A cover and startup gas supply system for a solid oxide fuel cell power generator is disclosed. Hydrocarbon fuel, such as natural gas or diesel fuel, and oxygen-containing gas are supplied to a burner. Combustion gas exiting the burner is cooled prior to delivery to the solid oxide fuel cell. The system mixes the combusted hydrocarbon fuel constituents with hydrogen which is preferably stored in solid form to obtain a non-explosive gas mixture. The system may be used to provide both non-explosive cover gas and hydrogen-rich startup gas to the fuel cell.

  15. Estimation of membrane hydration status for standby proton exchange membrane fuel cell systems by impedance measurement

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Rugholt, Mark; Nielsen, Morten Busk;

    2014-01-01

    Fuel cells are getting growing interest in both backup systems and electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However, the membrane of which PEMFCs are made tends to dry out when not in...... use. This increases the time required to start the system and could lead to the destruction of the fuel cell. In this article an impedance measurement circuit is presented, which is part of a humidity status estimator for monitoring the humidity status of a fuel cell stack during standby. The...

  16. A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

    International Nuclear Information System (INIS)

    Highlights: → Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. → An ideal artificial APCs system was successfully prepared in vivo. → Controlled release of IL-2 leads to much more T-cell expansion. → This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

  17. A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hui [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Peng, Ji-Run, E-mail: pengjr@medmail.com.cn [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Chen, Peng-Cheng; Gong, Lei [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Qiao, Shi-Shi [Department of Hepatobiliary Surgery, The First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052 (China); Wang, Wen-Zhen; Cui, Zhu-Qingqing; Yu, Xin; Wei, Yu-Hua [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Leng, Xi-Sheng, E-mail: lengxs2003@yahoo.com.cn [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China)

    2011-08-05

    Highlights: {yields} Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. {yields} An ideal artificial APCs system was successfully prepared in vivo. {yields} Controlled release of IL-2 leads to much more T-cell expansion. {yields} This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

  18. Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Turgut Gur

    2010-04-30

    This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

  19. Final Report: Development of a Thermal and Water Management System for PEM Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Zia Mirza, Program Manager

    2011-12-06

    This final program report is prepared to provide the status of program activities performed over the period of 9 years to develop a thermal and water management (TWM) system for an 80-kW PEM fuel cell power system. The technical information and data collected during this period are presented in chronological order by each calendar year. Balance of plant (BOP) components of a PEM fuel cell automotive system represents a significant portion of total cost based on the 2008 study by TIAX LLC, Cambridge, MA. The objectives of this TWM program were two-fold. The first objective was to develop an advanced cooling system (efficient radiator) to meet the fuel cell cooling requirements. The heat generated by the fuel cell stack is a low-quality heat (small difference between fuel cell stack operating temperature and ambient air temperature) that needs to be dissipated to the ambient air. To minimize size, weight, and cost of the radiator, advanced fin configurations were evaluated. The second objective was to evaluate air humidification systems which can meet the fuel cell stack inlet air humidity requirements. The moisture from the fuel cell outlet air is transferred to inlet air, thus eliminating the need for an outside water source. Two types of humidification devices were down-selected: one based on membrane and the other based on rotating enthalpy wheel. The sub-scale units for both of these devices have been successfully tested by the suppliers. This project addresses System Thermal and Water Management.

  20. Repurposing a Prokaryotic Toxin-Antitoxin System for the Selective Killing of Oncogenically Stressed Human Cells.

    Science.gov (United States)

    Preston, Mark A; Pimentel, Belén; Bermejo-Rodríguez, Camino; Dionne, Isabelle; Turnbull, Alice; de la Cueva-Méndez, Guillermo

    2016-07-15

    Prokaryotes express intracellular toxins that pass unnoticed to carrying cells until coexpressed antitoxin partners are degraded in response to stress. Although not evolved to function in eukaryotes, one of these toxins, Kid, induces apoptosis in mammalian cells, an effect that is neutralized by its cognate antitoxin, Kis. Here we engineered this toxin-antitoxin pair to create a synthetic system that becomes active in human cells suffering a specific oncogenic stress. Inspired by the way Kid becomes active in bacterial cells, we produced a Kis variant that is selectively degraded in human cells expressing oncoprotein E6. The resulting toxin-antitoxin system functions autonomously in human cells, distinguishing those that suffer the oncogenic insult, which are killed by Kid, from those that do not, which remain protected by Kis. Our results provide a framework for developing personalized anticancer strategies avoiding off-target effects, a challenge that has been hardly tractable by other means thus far. PMID:26230535

  1. Sliding Mode Control of the Battery Bank for the Fuel Cell-based Distributed Generation System

    Directory of Open Access Journals (Sweden)

    Junsheng Jiao

    2013-07-01

    Full Text Available The dynamic models for the fuel cell power and the configuration of the fuel cell distributed generation system are shown in this paper. Due to nonlinear characteristics of fuel cell model, the output voltage of fuel cell varies greatly when the load changes. A novel interface is designed to provide a constant output voltage for charging of the battery bank of the fuel cell distributed generation. The thesis presents a sliding mode control design of PEMFC distributed generation system. A cascaded control structure is chosen for ease of control realization and to exploit the motion separation property of power converters. The simulation results confirm the output current and voltage of the PEM fuel cell array converge rapidly to their reference values.

  2. Three-dimensional hydrogel cell culture systems for modeling neural tissue

    Science.gov (United States)

    Frampton, John

    Two-dimensional (2-D) neural cell culture systems have served as physiological models for understanding the cellular and molecular events that underlie responses to physical and chemical stimuli, control sensory and motor function, and lead to the development of neurological diseases. However, the development of three-dimensional (3-D) cell culture systems will be essential for the advancement of experimental research in a variety of fields including tissue engineering, chemical transport and delivery, cell growth, and cell-cell communication. In 3-D cell culture, cells are provided with an environment similar to tissue, in which they are surrounded on all sides by other cells, structural molecules and adhesion ligands. Cells grown in 3-D culture systems display morphologies and functions more similar to those observed in vivo, and can be cultured in such a way as to recapitulate the structural organization and biological properties of tissue. This thesis describes a hydrogel-based culture system, capable of supporting the growth and function of several neural cell types in 3-D. Alginate hydrogels were characterized in terms of their biomechanical and biochemical properties and were functionalized by covalent attachment of whole proteins and peptide epitopes. Methods were developed for rapid cross-linking of alginate hydrogels, thus permitting the incorporation of cells into 3-D scaffolds without adversely affecting cell viability or function. A variety of neural cell types were tested including astrocytes, microglia, and neurons. Cells remained viable and functional for longer than two weeks in culture and displayed process outgrowth in 3-D. Cell constructs were created that varied in cell density, type and organization, providing experimental flexibility for studying cell interactions and behavior. In one set of experiments, 3-D glial-endothelial cell co-cultures were used to model blood-brain barrier (BBB) structure and function. This co-culture system was

  3. A data integration approach for cell cycle analysis oriented to model simulation in systems biology

    Directory of Open Access Journals (Sweden)

    Mosca Ettore

    2007-08-01

    Full Text Available Abstract Background The cell cycle is one of the biological processes most frequently investigated in systems biology studies and it involves the knowledge of a large number of genes and networks of protein interactions. A deep knowledge of the molecular aspect of this biological process can contribute to making cancer research more accurate and innovative. In this context the mathematical modelling of the cell cycle has a relevant role to quantify the behaviour of each component of the systems. The mathematical modelling of a biological process such as the cell cycle allows a systemic description that helps to highlight some features such as emergent properties which could be hidden when the analysis is performed only from a reductionism point of view. Moreover, in modelling complex systems, a complete annotation of all the components is equally important to understand the interaction mechanism inside the network: for this reason data integration of the model components has high relevance in systems biology studies. Description In this work, we present a resource, the Cell Cycle Database, intended to support systems biology analysis on the Cell Cycle process, based on two organisms, yeast and mammalian. The database integrates information about genes and proteins involved in the cell cycle process, stores complete models of the interaction networks and allows the mathematical simulation over time of the quantitative behaviour of each component. To accomplish this task, we developed, a web interface for browsing information related to cell cycle genes, proteins and mathematical models. In this framework, we have implemented a pipeline which allows users to deal with the mathematical part of the models, in order to solve, using different variables, the ordinary differential equation systems that describe the biological process. Conclusion This integrated system is freely available in order to support systems biology research on the cell cycle and

  4. Cytokeratin changes in cell culture systems of epithelial cells isolated from oral mucosa: a short review.

    Science.gov (United States)

    Gasparoni, Alberto; Squier, Christopher Alan; Fonzi, Luciano

    2005-01-01

    In the past three decades, many studies have analyzed ultrastructural and molecular markers of differentiation in squamous stratified epithelial tissues. In these tissues, epithelial cells migrating from the basal layer to the upper layers undergo drastic changes, which involve membrane-associated proteins, DNA synthesis, phenotypic aspects, lipid composition, and cytoskeletal components. Cytoskeletal components include a large and heterogeneous group, including intermediate filaments, components of the cornified envelope, and of the stratum corneum. When grown in mono- and multilayer cell cultures, epithelial cells isolated from the oral mucosa may reproduce many of the biochemical and morphological aspects of epithelial tissue in vivo. In the present paper, we examine phenotypic changes, development of suprabasal layer, and Involucrin expression occurring in differentiating oral epithelial cells, based on literature review and original data. PMID:16277157

  5. CellSense: An Accurate Energy-Efficient GSM Positioning System

    CERN Document Server

    Ibrahim, Mohamed

    2011-01-01

    Context-aware applications have been gaining huge interest in the last few years. With cell phones becoming ubiquitous computing devices, cell phone localization has become an important research problem. In this paper, we present CellSense, a prob- abilistic RSSI-based fingerprinting location determi- nation system for GSM phones. We discuss the chal- lenges of implementing a probabilistic fingerprinting localization technique in GSM networks and present the details of the CellSense systemand how it addresses these challenges. We then extend the proposed system using a hybrid technique that combines probabilistic and deterministic estimation to achieve both high ac- curacy and low computational overhead.Moreover, the accuracy of the hybrid technique is robust to changes in its parameter values. To evaluate our proposed system, we implemented CellSense on Android-based phones. Results from two different testbeds, represent- ing urban and rural environments, for three differ- ent cellular providers show that Ce...

  6. Cell and Tissue Organization in the Circulatory and Ventilatory Systems Volume 1 Signaling in Cell Organization, Fate, and Activity, Part A Cell Structure and Environment

    CERN Document Server

    Thiriet, Marc

    2011-01-01

    The volumes in this authoritative series present a multidisciplinary approach to modeling and simulation of flows in the cardiovascular and ventilatory systems, especially multiscale modeling and coupled simulations. The cardiovascular and respiratory systems are tightly coupled, as their primary function is to supply oxygen to and remove carbon dioxide from the body's cells. Because physiological conduits have deformable and reactive walls, macroscopic flow behavior and prediction must be coupled to nano- and microscopic events in a corrector scheme of regulated mechanisms. Therefore, investigation of flows of blood and air in physiological conduits requires an understanding of the biology, chemistry, and physics of these systems together with the mathematical tools to describe their functioning.  The present volume is devoted to cellular events that allow adaptation to environmental conditions, particularly mechanotransduction. It begins with cell organization and a survey of cell types in the vasculatur...

  7. In colorectal cancer mast cells contribute to systemic regulatory T-cell dysfunction

    OpenAIRE

    Blatner, Nichole R.; Bonertz, Andreas; Beckhove, Philipp; Cheon, Eric C.; Krantz, Seth B.; Strouch, Matthew; Weitz, Juergen; Koch, Moritz; Halverson, Amy L.; Bentrem, David J.; Khazaie, Khashayarsha

    2010-01-01

    T-regulatory cells (Treg) and mast cells (MC) are abundant in colorectal cancer (CRC) tumors. Interaction between the two is known to promote immune suppression or loss of Treg functions and autoimmunity. Here, we demonstrate that in both human CRC and murine polyposis the outcome of this interaction is the generation of potently immune suppressive but proinflammatory Treg (ΔTreg). These Treg shut down IL10, gain potential to express IL17, and switch from suppressing to promoting MC expansion...

  8. Enrichment of prostate cancer cells from blood cells with a hybrid dielectrophoresis and immunocapture microfluidic system

    OpenAIRE

    Huang, Chao; Liu, He; Bander, Neil H.; Kirby, Brian J.

    2013-01-01

    The isolation of circulating tumor cells (CTCs) from cancer patient blood is a technical challenge that is often addressed by microfluidic approaches. Two of the most prominent techniques for rare cancer cell separation, immunocapture and dielectrophoresis (DEP), are currently limited by a performance tradeoff between high efficiency and high purity. The development of a platform capable of these two performance criteria can potentially be facilitated by incorporating both DEP and immunocaptu...

  9. Micromorph tandem solar cells: optimization of the microcrystalline silicon bottom cell in a single chamber system

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiao-Dan; Zheng Xin-Xia; Xu Sheng-Zhi; Lin Quan; Wei Chang-Chun; Sun Jian; Geng Xin-Hua; Zhao Ying

    2011-01-01

    We report on the development of single chamber deposition of microcrystalline and micromorph tandem solar cells directly onto low-cost glass substrates.The cells have pin single-junction or pin/pin double-junction structures on glass substrates coated with a transparent conductive oxide layer such as SnO2 or ZnO.By controlling boron and phosphorus contaminations,a single-junction microcrystalline silicon cell with a conversion efficiency of 7.47% is achieved with an i-layer thickness of 1.2 μm.In tandem devices,by thickness optimization of the microcrystalline silicon bottom solar cell,we obtained an initial conversion efficiency of 9.91% with an aluminum (Al) back reflector without a dielectric layer.In order to enhance the performance of the tandem solar cells,an improved light trapping structure with a ZnO/Al back reflector is used.As a result,a tandem solar cell with 11.04% of initial conversion efficiency has been obtained.

  10. Micromorph tandem solar cells: optimization of the microcrystalline silicon bottom cell in a single chamber system

    Science.gov (United States)

    Zhang, Xiao-Dan; Zheng, Xin-Xia; Xu, Sheng-Zhi; Lin, Quan; Wei, Chang-Chun; Sun, Jian; Geng, Xin-Hua; Zhao, Ying

    2011-10-01

    We report on the development of single chamber deposition of microcrystalline and micromorph tandem solar cells directly onto low-cost glass substrates. The cells have pin single-junction or pin/pin double-junction structures on glass substrates coated with a transparent conductive oxide layer such as SnO2 or ZnO. By controlling boron and phosphorus contaminations, a single-junction microcrystalline silicon cell with a conversion efficiency of 7.47% is achieved with an i-layer thickness of 1.2 μm. In tandem devices, by thickness optimization of the microcrystalline silicon bottom solar cell, we obtained an initial conversion efficiency of 9.91% with an aluminum (Al) back reflector without a dielectric layer. In order to enhance the performance of the tandem solar cells, an improved light trapping structure with a ZnO/Al back reflector is used. As a result, a tandem solar cell with 11.04% of initial conversion efficiency has been obtained.

  11. Spatial Organization of Cytokinesis Signaling Reconstituted in a Cell-Free System*

    OpenAIRE

    Nguyen, Phuong A.; Groen, Aaron C.; Loose, Martin; Ishihara, Keisuke; Wühr, Martin; Field, Christine M.; Mitchison, Timothy J.

    2014-01-01

    During animal cell division, the cleavage furrow is positioned by microtubules that signal to the actin cortex at the cell midplane. We developed a cell-free system to recapitulate cytokinesis signaling using cytoplasmic extract from Xenopus eggs. Microtubules grew out as asters from artificial centrosomes and met to organize antiparallel overlap zones. These zones blocked interpenetration of neighboring asters and recruited cytokinesis midzone proteins including the Chromosoma...

  12. Energy Analysis of a Fuel Cell System for Commercial Greenhouse Applications

    OpenAIRE

    Sardella, Marco

    2013-01-01

    Sustainable energy management becomes more important due to the ever more actual problems of environmental pollution and limited natural resources. The fuel cell technology is one of the most attractive solutions in this sense. During the past decades fuel cells have been investigated and demonstrated for several applications. One of the most attractive applications is using fuel cell system for stationary energy cogeneration (CHP), since they are capable of producing thermal energy and power...

  13. Lateral View Flow System for Studies of Cell Adhesion and Deformation under Flow Conditions

    OpenAIRE

    Yuan, Jin; Melder, Robert J; Jain, Rakesh K.; Munn, Lance L.

    2001-01-01

    Physical interactions between circulating cells and the vascular wall play a central role in inflammation, metastasis, atherosclerosis, and therapeutic cell delivery. Unfortunately, traditional in vitro flow assays cannot be used to visualize the details of cell-surface interactions in blood flow because of inappropriate geometry and the poor penetration of light in erythrocyte solutions. To overcome these obstacles, we have developed an agarose-cast cylindrical vessel system to examine the p...

  14. A Systems Model for Immune Cell Interactions Unravels the Mechanism of Inflammation in Human Skin

    OpenAIRE

    Valeyev, Najl V; Hundhausen, Christian; Umezawa, Yoshinori; Kotov, Nikolay V; Williams, Gareth; Clop, Alex; Ainali, Crysanthi; Ouzounis, Christos; Tsoka, Sophia; Nestle, Frank O

    2010-01-01

    Author Summary A functional immune system requires complex interactions among diverse cell types, mediated by a variety of cytokines. These interactions include phenomena such as positive and negative feedback loops that can be experimentally characterized by dose-dependent cytokine production measurements. However, any experimental approach is not only limited with regard to the number of cell-cell interactions that can be studied at a given time, but also does not have the capacity to asses...

  15. cellPACK: A Virtual Mesoscope to Model and Visualize Structural Systems Biology

    OpenAIRE

    Johnson, Graham T; Autin, Ludovic; Al-Alusi, Mostafa; Goodsell, David S.; Sanner, Michel F.; Olson, Arthur J.

    2014-01-01

    cellPACK assembles computational models of the biological mesoscale, an intermediate scale (10−7–10−8m) between molecular and cellular biology. cellPACK’s modular architecture unites existing and novel packing algorithms to generate, visualize and analyze comprehensive 3D models of complex biological environments that integrate data from multiple experimental systems biology and structural biology sources. cellPACK is currently available as open source code, with tools for validation of model...

  16. Calibration of a multi-load cells weighing system based on neural networks

    OpenAIRE

    Tavares, Adriano; Correia, J H; Couto, Carlos

    1995-01-01

    Multi-load cells weighting systems are based on a platform supported by four or more load cells, normally in parallel inputting lhe same signal conditioning unit. Because of mechanical and electrical paralleling tuning the gain of a load cell affects lhe behavior of the others, making the calibration difficult and tedious, specially withweightbridges for cars and trucb, requiring lhemotion of heavy weights around /arge p/atforms.

  17. Diminished Expression of Complement Regulatory Proteins on Peripheral Blood Cells from Systemic Lupus Erythematosus Patients

    OpenAIRE

    Ricardo Machado Xavier; João Carlos Tavares Brenol; Priscila Schmidt Lora; Odirlei Andre Monticielo; Amanda Kirchner Piccoli; Laiana Schneider; Ana Paula Alegretti

    2012-01-01

    CD55, CD59, CD46, and CD35 are proteins with complement regulatory (Creg) properties that ensure cell and tissue integrity when this system is activated. The aim of this study was to evaluate the Creg expression on peripheral blood cells from SLE patients and its association with cytopenia and disease activity. Flow cytometric analyses were performed on blood cells from 100 SLE patients and 61 healthy controls. Compared with healthy controls, we observed in SLE patients with lymphopenia and n...

  18. Cold-start effects on performance and efficiency for vehicle fuel cell systems

    OpenAIRE

    Gurski, Stephen Daniel

    2002-01-01

    In recent years government, academia and industry have been pursuing fuel cell technology as an alternative to current power generating technologies. The automotive industry has targeted fuel cell technology as a potential alternative to internal combustion engines. The goal of this research is to understand and quantify the impact and effects of low temperature operation has on the performance and efficiency of vehicle fuel cell systems through modeling. More specifically, this work addre...

  19. Circulating blood cells function as a surveillance system for damaged tissue in Drosophila larvae

    OpenAIRE

    Babcock, Daniel T.; Brock, Amanda R.; Fish, Greg S.; Wang, Yan; Perrin, Laurent; Krasnow, Mark A.; Galko, Michael J.

    2008-01-01

    Insects have an open circulatory system in which the heart pumps blood (hemolymph) into the body cavity, where it directly bathes the internal organs and epidermis. The blood contains free and tissue-bound immune cells that function in the inflammatory response. Here, we use live imaging of transgenic Drosophila larvae with fluorescently labeled blood cells (hemocytes) to investigate the circulatory dynamics of larval blood cells and their response to tissue injury. We find that, under normal...

  20. Subpopulations of Regulatory T Cells in Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Behcet's Disease

    OpenAIRE

    KIM, JAE-RYONG; Chae, Jin-Nyeong; Kim, Sang-Hyon; Ha, Jung-Sook

    2012-01-01

    Recently, subpopulations of regulatory T (Treg) cells, resting Treg (rTreg) and activated Treg (aTreg), have been discovered. The authors investigated the relationship between the change of Treg, aTreg and rTreg and autoimmune diseases. Treg cells and those subpopulations were analyzed by using the human regulatory T cell staining kit and CD45RA surface marker for 42 rheumatoid arthritis (RA), 13 systemic lupus sclerosis (SLE), 7 Behcet's disease (BD), and 22 healthy controls. The proportion ...

  1. Exergoeconomic analysis of vehicular PEM (proton exchange membrane) fuel cell systems with and without expander

    International Nuclear Information System (INIS)

    In this paper we perform an exergoeconomic analysis to a PEM (proton exchange membrane) vehicular fuel cell system used in the latest generation of environmentally friendly cars. Two alternative configurations of a fuel cell system are considered (with and without an expander), and two alternative design concepts for each configuration: BoL (Begin of Life) and EoL (End of Life). The system including an expander generates additional power from the exhaust gases leaving the fuel cell stack, which might increase the system efficiency. However the total investment costs for this case are higher than for the other system configuration without an expander, due to the investment costs associated with the expander and its accessories. The fuel cell stack area in the EoL-sized systems is larger than in the BoL-sized systems. A larger stack area on one hand raises the investment costs, but on the other hand decreases the fuel consumption due to a higher cell efficiency. In this paper, exergoeconomic analyses have been implemented to consider a trade-off between positive and negative effects of using an expander in the system and to select the proper design concept. The results from the exergoeconomic analysis show that (a) an EoL-sized system with an expander is the most cost effective system, (b) the compression and humidification of air are very expensive processes, (c) the stack is by far the most important component from the economic viewpoint, and (d) the thermodynamic efficiency of almost all components must be improved to increase the cost effectiveness of the overall system. - Highlights: • Two vehicular PEM (proton exchange membrane) fuel cell system configurations are studied in this paper. • Exergoeconomics has been performed to compare these two system configurations. • The compression and humidification of air are very expensive processes. • The stack is by far the most important component from the economic viewpoint. • The thermodynamic efficiencies

  2. Energy system analysis of fuel cells and distributed generation

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik

    2007-01-01

    technologies are very often connected to the use of hydrogen, which has to be provided e.g. from electrolysers. Decentralised and distributed generation has the possibility of improving the overall energy efficiency and flexibility of energy systems. Therefore, energy system analysis tools and methodologies...

  3. Artificial neural network control strategies for fuel cell hybrid system

    OpenAIRE

    Oheda, Hakim

    2013-01-01

    The greening of air transport is the driver for developing technologies to reduce the environmental impact of aviation with the aim of halving the amount of carbon dioxide (COଶ) emitted by air transport, cutting specific emissions of nitrogen oxides (NO୶) by 80% and halving perceived noise by the year 2020. Fuel Cells (FC) play an important role in the new power generation field as inherently clean, efficient and reliable source of power especially when comparing with the tradi...

  4. Alternative redox systems for the dye-sensitized solar cell

    OpenAIRE

    Nusbaumer, Hervé; Grätzel, Michael

    2005-01-01

    Due to their high efficiencies and their potentially low production costs, dye-sensitized solar cells (DSSC) have attracted much attention during the last few years. The technology is based on a layer made of mesoscopic TiO2 film which significantly increases the optical path for light harvesting by the surface-anchored sensitizer molecules, whilst keeping an efficient contact with the electrolytic solution. These sensitizer molecules are often based on ruthenium polypyridyl complexes because...

  5. Alternative redox systems for the dye-sensitized solar cell

    OpenAIRE

    Nusbaumer, Hervé

    2004-01-01

    Due to their high efficiencies and their potentially low production costs, dye-sensitized solar cells (DSSC) have attracted much attention during the last few years. The technology is based on a layer made of mesoscopic TiO2 film which significantly increases the optical path for light harvesting by the surface-anchored sensitizer molecules, whilst keeping an efficient contact with the electrolytic solution. These sensitizer molecules are often based on ruthenium polypyridyl complexes because...

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

    Science.gov (United States)

    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.

  7. [Cashmere goat bacterial artificial chromosome recombination and cell transfection system].

    Science.gov (United States)

    Huang, Tian; Cao, Zhongyang; Yang, Yaohui; Cao, Gengsheng

    2016-03-01

    The Cashmere goat is mainly used to produce cashmere, which is very popular for its delicate fiber, luscious softness and natural excellent warm property. Keratin associated protein (KAP) and bone morphogenetic protein (BMP) of the Cashmere goat play an important role in the proliferation and development of cashmere fiber follicle cells. Bacterial artificial chromosome containing kap6.3, kap8.1 and bmp4 genes were used to increase the production and quality of Cashmere. First, we constructed bacterial artificial chromosomes by homology recombination. Then Tol2 transposon was inserted into bacterial artificial chromosomes that were then transfected into Cashmere goat fibroblasts by Amaxa Nucleofector technology according to the manufacture's instructions. We successfully constructed the BAC-Tol2 vectors containing target genes. Each vector contained egfp report gene with UBC promoter, Neomycin resistant gene for cell screening and two loxp elements for resistance removing after transfected into cells. The bacterial artificial chromosome-Tol2 vectors showed a high efficiency of transfection that can reach 1% to 6% with a highest efficiency of 10%. We also obtained Cashmere goat fibroblasts integrated exogenous genes (kap6.3, kap8.1 and bmp4) preparing for the clone of Cashmere goat in the future. Our research demonstrates that the insertion of Tol2 transposons into bacterial artificial chromosomes improves the transfection efficiency and accuracy of bacterial artificial chromosome error-free recombination. PMID:27349114

  8. Thermal modeling and temperature control of a PEM fuel cell system for forklift applications

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen;

    2014-01-01

    Temperature changes in PEM fuel cell stacks are considerably higher during load variations and have a negative impact as they generate thermal stresses and stack degradation. Cell hydration is also of vital importance in fuel cells and it is strongly dependent on operating temperature. A combinat......Temperature changes in PEM fuel cell stacks are considerably higher during load variations and have a negative impact as they generate thermal stresses and stack degradation. Cell hydration is also of vital importance in fuel cells and it is strongly dependent on operating temperature. A...... combination of high temperature and reduced humidity increases the degradation rate. Stack thermal management and control are, thus, crucial issues in PEM fuel cell systems especially in automotive applications such as forklifts. In this paper we present a control–oriented dynamic model of a liquid–cooled PEM...... designers in choosing the required coolant mass flow rate and radiator size to minimize the stack temperature gradients....

  9. Rapid assay system for cytotoxicity tests using 14C-leucine incorporation into tumor cells

    International Nuclear Information System (INIS)

    Cell viability under various conditions of cytotoxicity test was assessed by terminal labeling of tumor cells, T24 cell line derived from urinary bladder carcinoma, with 14C-leucine. Changes of 14C-leucine incorporation into the cells were fairly proportional to those of viable cell number measured by the trypan blue exclusion method, but a definite correlation between the two measurements was not always found following cytotoxic manipulations. When the cells were labeled immediately after drug treatments, 14C-leucine incorporation usually led to fluctuated and insensitive results presumably due to disturbed metabolic activities unrelated to cell viability and failed to indicate the degree of cell damage. It was shown, however, that the cytotoxicity test was satisfactorily determined by labeling tumor cells with 14C-leucine after recovery in fresh medium for 24 hr. Cytotoxic effects of anticancer drugs with concentration- and time-dependency, hyperthermia and phytohemagglutinin-stimulated lymphocytes were demonstrated by the radioactivity incorporated into the target cells on day 2 after removal of the cytotoxic factors. The results indicate that the terminal labeling of tumor cells with 14C-leucine can be used as a rapid and reliable measure sensitivities to cell viability for an in vitro assay system. (author)

  10. Automatic Detection of Cervical Cancer Cells by a Two-Level Cascade Classification System

    Science.gov (United States)

    Su, Jie; Xu, Xuan; He, Yongjun; Song, Jinming

    2016-01-01

    We proposed a method for automatic detection of cervical cancer cells in images captured from thin liquid based cytology slides. We selected 20,000 cells in images derived from 120 different thin liquid based cytology slides, which include 5000 epithelial cells (normal 2500, abnormal 2500), lymphoid cells, neutrophils, and junk cells. We first proposed 28 features, including 20 morphologic features and 8 texture features, based on the characteristics of each cell type. We then used a two-level cascade integration system of two classifiers to classify the cervical cells into normal and abnormal epithelial cells. The results showed that the recognition rates for abnormal cervical epithelial cells were 92.7% and 93.2%, respectively, when C4.5 classifier or LR (LR: logical regression) classifier was used individually; while the recognition rate was significantly higher (95.642%) when our two-level cascade integrated classifier system was used. The false negative rate and false positive rate (both 1.44%) of the proposed automatic two-level cascade classification system are also much lower than those of traditional Pap smear review. PMID:27298758

  11. Systems Modelling and the Development of Coherent Understanding of Cell Biology

    Science.gov (United States)

    Verhoeff, Roald P.; Waarlo, Arend Jan; Boersma, Kerst Th.

    2008-01-01

    This article reports on educational design research concerning a learning and teaching strategy for cell biology in upper-secondary education introducing "systems modelling" as a key competence. The strategy consists of four modelling phases in which students subsequently develop models of free-living cells, a general two-dimensional model of…

  12. Vision-based Nano Robotic System for High-throughput Non-embedded Cell Cutting

    Science.gov (United States)

    Shang, Wanfeng; Lu, Haojian; Wan, Wenfeng; Fukuda, Toshio; Shen, Yajing

    2016-03-01

    Cell cutting is a significant task in biology study, but the highly productive non-embedded cell cutting is still a big challenge for current techniques. This paper proposes a vision-based nano robotic system and then realizes automatic non-embedded cell cutting with this system. First, the nano robotic system is developed and integrated with a nanoknife inside an environmental scanning electron microscopy (ESEM). Then, the positions of the nanoknife and the single cell are recognized, and the distance between them is calculated dynamically based on image processing. To guarantee the positioning accuracy and the working efficiency, we propose a distance-regulated speed adapting strategy, in which the moving speed is adjusted intelligently based on the distance between the nanoknife and the target cell. The results indicate that the automatic non-embedded cutting is able to be achieved within 1–2 mins with low invasion benefiting from the high precise nanorobot system and the sharp edge of nanoknife. This research paves a way for the high-throughput cell cutting at cell’s natural condition, which is expected to make significant impact on the biology studies, especially for the in-situ analysis at cellular and subcellular scale, such as cell interaction investigation, neural signal transduction and low invasive cell surgery.

  13. Isotropic averaging for cell-dynamical-system simulation of spinodal decomposition

    Indian Academy of Sciences (India)

    Anand Kumar

    2003-07-01

    Formulae have been developed for the isotropic averagings in two and three dimensions. Averagings are employed in the cell-dynamical-system simulation of spinodal decomposition for inter-cell coupling. The averagings used in earlier works on spinodal decomposition have been discussed.

  14. Miniaturized Mass-Spectrometry-Based Analysis System for Fully Automated Examination of Conditioned Cell Culture Media

    NARCIS (Netherlands)

    Weber, E.; Pinkse, M.W.H.; Bener-Aksam, E.; Vellekoop, M.J.; Verhaert, P.D.E.M.

    2012-01-01

    We present a fully automated setup for performing in-line mass spectrometry (MS) analysis of conditioned media in cell cultures, in particular focusing on the peptides therein. The goal is to assess peptides secreted by cells in different culture conditions. The developed system is compatible with M

  15. Systemic mastocytosis presenting as cardiac tamponade with CD25(+) pericardial mast cells.

    Science.gov (United States)

    Sukrithan, Vineeth K; Salamon, Jason N; Berulava, Giorgi; Sibinga, Nicholas E; Verma, Amit

    2016-03-01

    In this first-in-literature case, we describe a patient with Systemic mastocytosis presenting with life-threatening cardiac tamponade associated with the presence of aberrant mast cells in the pericardium. Procedures involving surgical incisions through the pericardium in such cases can lead to uncontrolled mast cell degranulation leading to circulatory collapse. PMID:27014452

  16. An integrated approach for the cell formation and layout design in cellular manufacturing systems

    NARCIS (Netherlands)

    Javadi, Babak; Jolai, Fariborz; Slomp, Jannes; Rabbani, Masoud; Tavakkoli-Moghaddam, Reza

    2013-01-01

    In this paper, a comprehensive model is presented for cell formation and layout design in cellular manufacturing systems (CMS). The proposed model incorporates an extensive coverage of important operational features and especially layout design aspects to determine optimal cell configuration and Int

  17. Disparate Requirement for T Cells in Resistance to Mucosal and Acute Systemic Candidiasis

    OpenAIRE

    Jones-Carson, Jessica; Vazquez-Torres, Andres; Warner, Thomas; Balish, Edward

    2000-01-01

    Although highly susceptible to orogastric candidiasis, T-cell receptor δ- and α-chain knockout mice, deficient in γδ and αβ T cells, respectively, were found to be resistant to disseminated candidiasis of endogenous origin and to acute systemic candidiasis (resulting from intravenous injection).

  18. Regulation of fibrotic phenotype of the fibroblast cell system by TGF-b

    International Nuclear Information System (INIS)

    Radiation fibrosis of various organs is a multicellular process mediated through the action of specific growth factors and cytokines. Although different cell systems, i.e. endothelial and epithelial cells, macrophages and fibroblasts are involved in the induction and manifestation of fibrosis, the fibrogenic tissue remodeling is mainly due to the action of the fibroblast/fibrocyte cell system. This cell system is stimulated by irradiation to alter its differentiation pattern and collagen production leading to the fibrosis-specific production and deposition of interstitial collagens. Normally the fibroblast/fibrocyte cell system presents a 2:1 ratio of progenitor fibroblasts and terminal differentiated functioning fibrocytes. As shown by the use of TGF-b1 knock-out systems, the cytokine TGF-b1 is a major determinant of fibroblasts' radiation sensitivity and differentiation. TGF-b1 activated in response to radiation from its latent form (LTGF), TGF-b1 regulates the radiation-induced terminal differentiation of the fibroblast cell system through the TGF-b1 receptor II-dependent Smad signaling cascade. As a result of this pathway the expression of cell cycle inhibitors such as p21 and p27 is induced leading to a permanent cell cycle arrest and terminal differentiation of progenitor fibroblasts into collagen producing postmitotic fibrocytes. Antagonizing the protease-dependent and radiation-induced activation step of LTGF-b1 to TGF-b1 or neutralizing active TGF-b1 by specific antibodies inhibits the induction of the fibrotic phenotype of the fibroblast cell system. Applying in situ hybridization techniques, the same molecular and cellular response pattern as shown in in vitro cultures could be demonstrated for lung tissue in vivo

  19. A portable system powered with hydrogen and one single air-breathing PEM fuel cell

    International Nuclear Information System (INIS)

    Highlights: • A portable system based on hydrogen and single air breathing PEM fuel cell. • Control electronics designed for low single cell voltage (0.5–0.8 V). • Forced air convection and anode purging required to help water management. • Application consisting of a propeller able to display a luminous message. • Up to 20 h autonomy with continuous 1.1 W consumption, using 1 g H2. - Abstract: A portable system for power generation based on hydrogen and a single proton exchange membrane fuel cell (PEMFC) has been built and operated. The fuel cell is fed in the anode with hydrogen stored in a metal hydrides cartridge, and in the cathode with oxygen from quiescent ambient air (‘air breathing’). The control electronics of the system performs DC–DC conversion from the low voltage (0.5–0.8 V) and high current output (200–300 mA cm−2) of the single fuel cell, up to 3.3 V to power an electronic application. System components assist fuel cell operation, including an electronic valve for anode purging, a fan in front of the open cathode, two supercapacitors for auxiliary power requirements, four LED lights, and a display screen. The influence of the system components on fuel cell behaviour is analyzed. The cathode fan and anodic purging help excess water removal from the electrodes leading to steadier cell response at the expense of extra power consumption. The power system is able to provide above 1 W DC electricity to an external application during 20 h using 1 g of H2. An application consisting of a propeller able to display a luminous message is chosen to test system. It is shown that one single air breathing PEM fuel cell powered with hydrogen may provide high energy density and autonomy for portable applications

  20. Fuel cell/back-up battery hybrid energy conversion systems: Dynamic modeling and harmonic considerations

    International Nuclear Information System (INIS)

    Highlights: • Novel technique to completely eliminate the harmful harmonics of fuel cell system. • Presenting a novel high accurate detailed electrochemical dynamic model of fuel cells. • Back-up battery system to compensate the slow dynamic response of fuel cell system. • Exact analysis of real electrochemical reactions occurring inside fuel cells. - Abstract: In this study, a novel dynamic model of fuel cells is presented. High accurate static and dynamic responses of the proposed model are experimentally validated by comparing simulated results with real experimental data. The obtained model together with theoretical results shows that a fuel cell or a fuel cell stack has very slow dynamic response, so that, it cannot adapt itself to the fast variations in load demand. It is shown that for adapting well a fuel cell stack to the load demand, the stack should be equipped with a proposed back-up battery system which compensates the slow dynamic response of the stack by providing a bidirectional path to transmit/absorb the extra instant power. It is proved that the conventional switching waveforms used in the converters of the stacks and back-up systems produce an enormous amount of harmful harmonics. Then, a novel technique is proposed to completely eliminate main harmful harmonics. It is worthwhile to note that all the other techniques only reduce the harmful harmonics. Simulated results verify that the back-up battery system together with applying the proposed technique provide a fast dynamic response for the fuel cell/back-up battery system, and also completely eliminate the main harmful harmonics